Occlusal guidance

Occlusal Guidance In
Pediatric Dentistry
Dr. Lilavanti Vaghela
MDS in Pediatric and Preventive Dentistry

Content
▪ Introduction
▪ Definition of occlusal guidance
▪ Significance of occlusal guidance
▪ Development of the dental arch and occlusion
1. The primary Dentition
2. Eruption of the first molar
3. The exchange of incisors
4. Exchange of the lateral teeth (canines and premolars)
5. Eruption of the second permanent molar
6. Local factors affecting the exchange of teeth
▪ Diagnosis in occlusal guidance
▪ Treatment plan in occlusal guidance
1. Treatment in passive occlusal guidance
2. Treatment in active occlusal guidance
✓ Clinical examples of cases treated by occlusal guidance
▪ Conclusion
▪ References

✓ Many changes in the craniofacial and oral structures occur during a child's growth and
development.
✓ The ultimate goal of the pediatric dentist is to develop a perfect and healthy occlusion
in the permanent dentition by preventive, interceptive, and corrective treatments that
are timed precisely according to the changes in dentition and jaws which result from
that growth and development.
✓ The concept embodied in this clinical management system is known as "occlusal
guidance".
Introduction
Occlusal GuidanceinPediatricDentistry, Minoru Nakata,
Stephen H.Y. Wei: ISBN0-912791-63-2

✓ In its broadest sense, the concept of occlusal guidance involves virtually all treatment
carried out in pediatric dentistry.
Significance of dental treatment in the primary dentition
Significance of occlusal guidance

✓ Therefore, the final goal of all dental treatments for the child is the establishment
of a healthy occlusion in the permanent dentition.
✓ Again, any treatment contributing to this goal may -- broadly speaking -- be
considered an aspect of "occlusal guidance".
✓ However, in a more definitive sense, a narrower range of treatment modalities
should be considered the essential aspects of occlusal guidance.

Specific treatment modalities can be grouped according to two categories.
✓ The first involves ensuring that
the dental arch of the primary
dentition is maintained
throughout the exfoliation of the
primary teeth and their
succession by the normal
permanent dentition.
✓ e.g. use of space maintenance
appliances
Passive occlusal guidance
✓ The second modality involves
the detection of any
abnormality at an early stage
of development of the dental
arches and occlusion, and the
implementation of interceptive
and corrective treatment.
✓ Also called as "preventive
orthodontics"
Active occlusal guidance

The specific treatments carried out as part of occlusal guidance then, include the following:
Passive occlusal guidance
(1) Space maintenance
(2) Properly timed and planned extraction of teeth
Active occlusal guidance
(1) Space regaining
(2) Occlusal adjustment during the mixed dentition period
(3) Early detection and treatment of ectopic eruption of teeth
(4) Early detection, interception and treatment of occlusal disharmony and
abnormalities
(5) Control of oral habits

✓ The causative factors of occlusal abnormalities which may adversely affect the normal
growth and development of the teeth and occlusion include genetic variations in shape
and size of the teeth and jaws, congenital abnormalities, plus environmental and local
factors influencing the oral structures.
✓ These factors may be prevented, their detrimental effects minimized, or the conditions
treated early before their full-blown manifestation.
✓ It is not unusual to encounter such clinical cases, and if not properly managed during
the course of dental development, they may result in unnecessary treatment for much
longer time periods than strictly necessary.

✓ Various malocclusion problems mostly develop during the period of transition from primary to
✓ It is therefore most important to carefully monitor the occlusal development of children at an early
age in order to reduce the degree of severity of any malocclusion.
✓ For dental practitioners who regularly observe and follow the dental health of their child patients, this
is one of the most important and basic aspects of the recall examination.
✓ The responsibility of pediatric dentists is therefore very great.
✓ Fortunately, this is also one of the most enjoyable aspects of treating children.
✓ The emphasis in dentistry for children is clearly shifting towards an increased awareness of
prevention, not only of dental caries and periodontal disease, but also in preventing the disharmony of
oral functions as a result of malocclusion.
Role of pediatric dentist

Characteristics of occlusal guidance
The basic principle of occlusal guidance → to maintain the integrity of the arch form and
teeth in the primary dentition, and then to achieve a smooth transition from the primary to the
✓ It is not an exaggeration to state that this is the fundamental philosophy which supports all
dental treatments undertaken for children.
✓ However, even when one practices this concept of maintaining the integrity of the primary
dentition, a normal permanent dentition with optimal occlusion is not always guaranteed.

✓ When we consider the primary dentition as the foundation for the permanent dentition, the need for the
succedaneous teeth to correspond, in a relative sense, to the size of their primary predecessors becomes
apparent.
one third of all individuals
will develop a harmonious
relationship in the
permanent teeth.
Correlations of tooth size between the primary and succedaneous teeth.

✓ In other words, it is impossible to accurately predict the conditions of the permanent dentition from
the primary dentition.
✓ This means that even if the development of the permanent dentition has been managed properly, the
primary dentition has functioned normally, and the transition of the dentitions has occurred smoothly
and uneventfully, there still may be a chance of malocclusion.
✓ Therefore, simply facilitating a smooth exchange of the dentitions is --in itself- insufficient to
establish a normal permanent occlusion.

✓ Characteristic of applied occlusal guidance is mainly due to the problem that patients and their
parents have a very low awareness of malocclusion and their treatment needs.
✓ The situation is similar to the problem of generally low dental awareness and the difficulty of
trying to get the patients' understanding and cooperation for preventive or early treatment of teeth,
when there are no obviously decayed teeth or gross cavities, and they have experienced little or no
pain.

✓ In short, occlusal guidance is based on a method of "prediction".
✓ The result of the ensuing treatment is, of course, largely dependent on the
accuracy of the prediction.
✓ At present, there is - to our knowledge - no completely accurate method of
prediction that can guarantee no failures.
✓ This is why children must always see their dentists regularly. Otherwise,
occlusal guidance may not be successful.
✓ This principle applies also to other aspects of pediatric dental care.

Development of the dental arch and occlusion
✓ As a general rule, the characteristic changes
associated with growth and development are
continuous.
✓ But from the clinical point of view, there is a
need to classify these continuous changes into
several characteristic stages.
✓ In order to evaluate the growth of children,
dental age is more clinically useful than
chronological age, because it is based on the
development of the dentition.
Hellman's dental stages (Hellman, 1929)
The classical and traditional evaluation of dentitional development.

Stages of occlusal development from the clinical point of
view (Barnett. 1978)

✓ The distal surface of the second primary molar (the 1st stage) guides the site of eruption of
the first permanent molar (the 2nd stage).
✓ The mesial surface of the primary canine (the 1st stage) guides the location and arrangement
of the permanent incisors (the 3rd stage).
✓ After that, the canine and two premolars erupt in the limited space between the mesial
surface of the first permanent molar (the 2nd stage) and the distal surface of the lateral
incisor (the 3rd stage).
✓ The distal surface of the first permanent molar (the 2nd stage) guides the second permanent
molar, completing the development of the permanent dental arch and occlusion (the 5th
stage).
✓ If dental development occurs normally at every stage, and the stages occur in the proper
sequence, there is a good chance that a normal healthy permanent dentition and occlusion
will be established.

1. The Primary Dentition
✓ Initiation of' the primary tooth buds occurs during the first 6 weeks of intra-uterine life.
✓ The eruption of the first primary tooth begins at about 6 months after birth, and all primary teeth
are usually erupted by 2 1/2 years of age, when the second primary molars come into occlusion.
✓ However, at this age, the roots of the second primary molars are usually not yet complete

✓ Therefore, the establishment of the primary dentition is usually considered to take place at about
3 years of age when the roots of the second primary molars complete their development, and to
last until about 6 years of age when the first permanent tooth begins to erupt.
✓ From 3 to 4 years of age, the dental arch is relatively stable and changes very slightly.
✓ From 5 to 6 years of age, the size of the dental arch begins to change due to the eruptive force of
the first permanent molar.
✓ During this period, one must observe changes in the primary dentition carefully because these
changes are indicative of what may be the prototype of the future permanent dentition.

1) Spaces in the primary dentition
2) Occlusal relationship of the second primary molars
3) Size of the dental arch

1) Spaces in the primary dentition
Primate space/Simian space/Anthropoid space
✓ It is very common to find physiological spaces in the primary dentition, with the most
prevalent spaces mesial to the primary canine in the maxilla, and distal to the primary canine
in the mandible.
✓ The other spaces in the primary dentition are called the developmental spaces. Such dental
spaces are termed "physiological spaces", and pay an important role in the normal
development of the permanent dentition.

2) Occlusal relationship of the second primary molars
✓ The primary dentition is complete after the eruption of the second primary molars.
✓ This means that the location for eruption of the permanent teeth in the future has already been
determined at this stage.
✓ In other words, the dental arch circumference that connects the most distal surfaces of the
right and left second primary molars should be preserved for the permanent dentition after the
exchange of dentitions, and the space behind the primary molars is adequate for the permanent
molars space including the first permanent molars.
✓ The relation of the distal surface of the maxillary and mandibular second primary molars is,
therefore, one of the most important factors that influence the future occlusion of the

• The mesio-distal relation between the distal surface of the upper and lower second primary
molars is called the terminal plane when the primary teeth contact in the centric occlusion.
• The terminal plane can be classified into the three types.

The prevalence of various types of terminal planes
Study of occlusal characteristics of primary dentition and the
prevalence of maloclusion in 4 to 6 years old children in
India
(Bhayya DP et at; India. Dent Res J (Isfahan). 2012;9(5):619-623.)
Occlusal characteristic found were-- flush terminal plane
(52.5%), class I canine relationship (84%), maxillary
developmental spaces (35.4%), primate spaces in maxilla
(47.6%), mandibular crowding (4.6%)
Occlusal Characteristics and Spacing in Primary Dentition: A
Gender Comparative Cross-Sectional Study
(Madhuri Vegesna et al, International Scholarly Research Notices
Volume 2014, Article ID 512680, 7 pages)
The flush terminal plane molar relation (80.3%) was the most
common primary molar relation. The distal step molar
relation was more frequently found in female children
(12.8%) than in males (8.6%).

3) Size of the dental arch
✓ The size of the primary dental arch can be
measured by the dental arch width between the
primary canines and between the second primary
molars.
✓ The dental arch length can be measured from the
most labial surface of the primary central
incisors to the canines and to the second primary
molars.
✓ The dental arch width increases a little during
the primary dentition period, especially between
the primary molars. On the contrary, the dental
arch length tends to decrease as a rule.

2. Eruption of the first molar
✓ The first permanent molar is the key to the permanent occlusion of the teeth.
✓ It plays a very important role in the establishment and function of the
occlusion of the permanent dentition.
1) Pathway of eruption of the first molars
2) Establishment of occlusion of the first permanent molars

1) Pathway of eruption of the first molars
• The tooth germ of the
maxillary first permanent
molar develops in the
maxillary tuberosity, and its
occlusal surface is usually
oriented downwards and
backwards
• The tooth germ of the
mandibular first permanent
molar is usually located at
the corner of the mandibular
gonion with its occlusal
surface facing upwards and
forwards
Maxilla Mandible

✓ The terminal plane is very important in determining the interocclusal relationship of the first
permanent molars.
✓ As soon as a first permanent molar erupts into the oral cavity, it comes in contact with the distal
surface of the second primary molar.
✓ However, its location during this period is not stable until the final interocclusal relation has been
established, when the intercuspal digitation between the maxillary and mandibular first permanent
molars has been achieved.
✓ During this process, any unusual spaces created by the carious or traumatic destruction of the tooth
crown and/ or premature loss of the primary teeth will result in the mesial shift of the first molar in
various ways due to the presence of physiological spaces in the primary dentition

2) Establishment of occlusion of the first permanent molars
✓ How the first molars will occlude may be predicted to some extent at the primary dentition stage.
a. Vertical plane type
If the dental spaces existed in the
primary dental arch, the first
molars will erupt into Class I
occlusion. If not, they will erupt
into a cusp-to-cusp occlusion.
b. Mesial step type
The first molars erupt directly
into Angle's Class I occlusion.
c. Distal step type
The first molars erupt directly
and definitively into Angle's
Class II occlusion.

• When the terminal plane is the vertical type, the interocclusal
relationship of the first molars will be unstable in cusp to
cusp occlusion.
• In this case, if physiological spaces exist in the primary
dentition, there will be a chance for the occlusion to become
Class I.
• If there are physiological spaces, such as the primate or
developmental spaces in the mandible, an eruptive force in
the mesial direction by the mandibular first permanent molar
will close the existing spaces in the dental arch to push the
primary molars mesially.
• Because the lower teeth usually erupt earlier than the upper
teeth, the lower molars will move mesially as much as the
amount of space reduction which enables them to erupt into
a Class I occlusion.

✓ The relationships between the various types of terminal planes and the occlusion of
the first permanent molars were as follows: with the mesial step type of terminal
plane, the occlusion changed to → Class 1,49%; Class II, 9%; and Class III, 42%.
✓ With the vertical plane type, the change was to → Class I,67%; and Class II,33%.
✓ With the distal step type, the change in occlusion was to → Class II, 100%.
(Nabeta et al, 1982).

Modified Angle’s Classification for Primary Dentition
✓ Angle used capital Roman numbers I/II/III to identify Class I, Class II, and Class III
malocclusions, respectively.
✓ Janson et al. [2010] have described half cusp Class II or III and Class II or III
severity of malocclusions.
Chandranee KN, Chandranee NJ, Nagpal D, Lamba G, Choudhari P, Hotwani K. Modified angle's classification for
primary dentition. Contemp Clin Dent 2017;8:617-20.

Class i: When the mesiobuccal cusp of the primary maxillary second molar occludes with the mesiobuccal groove of the primary
mandibular second molar
Class ii: When the mesiobuccal cusp of the primary maxillary second molar occludes with the interdental space between primary
mandibular first and second molar
Class iii: When the mesiobuccal cusp of the primary maxillary second molar occludes with the distobuccal groove or distal surface of the
primary mandibular second molar
Half cusp Class ii: When the mesiobuccal cusp of the primary maxillary second molar occludes with the mesiobuccal cusp of the primary
Half cusp Class iii: When the mesiobuccal cusp of the primary maxillary second molar occludes with the distobuccal cusp of the primary
Subdivision: When molar relationships on both sides in a child is different wherein one side is Class i and the other being any one of the
other types described above. The subdivision is the side which is not Class i side.

Significance of modified angle’s classification
✓ Children having various combinations of Class ii and Class iii, primary molar relationships are the
cases having unilateral Class i and/or transient unstable unilateral/bilateral half cusp Class ii or
Class iii molar relationships may need supervision, monitoring, and depending on their transition
into full cusp Class ii or Class iii molar relationships may need interceptive and/or corrective
orthodontic measures.
Chandranee KN, Chandranee NJ, Nagpal D, Lamba G, Choudhari P, Hotwani K. Modified angle's classification for
primary dentition. Contemp Clin Dent 2017;8:617-20.

✓ According to Nance (1947) the extra space obtained at the exchange of the lateral teeth,
known as the Leeway space, is the factor which determines whether the molars move
into Class I after the adjustment of cusp-to-cusp occlusion by the first molars.
✓ Regulatory factors for occlusal relation
Second primary molar's occlusion,
The spaces in the primary dentition,
The growth of the maxilla and mandible.

3. The exchange of incisors
✓ Before and after the eruption of the first molars, the primary incisors begin to
exchange with the permanent incisors, starting from the lower central incisors.
✓ The total sum of the mesio- distal width of the four permanent incisors is larger than
that of the primary incisors by about 7 mm in the maxilla, and by about 5 mm in the
mandible.
✓ Remarkable changes occur in the dental arch during the exchange of incisors to
accommodate the much larger permanent incisors.
✓ Moorrees (1965) found that the total space in the dental arch appears to became
deficient. In other words, there is usually some crowding during the exchange of
canines and lateral incisors.

Changes in interdental spaces in the incisor segment due to the exchange of the
permanent incisors. The vertical axis shows the amount of space gain (+) or loss (-). The
time of eruption of each permanent tooth is indicated by arrows (Moorrees, 1965).

• How the incisors are arranged will also influence whether or not the canines and
premolars are arranged normally in the next stage.
• The regulatory factors controlling the arrangement of the four permanent incisors can be
summarized according to the following five stages.
1) Interdental spaces in the primary incisor region
2) Increase of inter canine width
3) Increase of anterior length in the dental arch
4) Change of tooth axis of incisors
5) Ugly duckling stage

1) Interdental spaces in the primary incisor region
✓ The physiological spaces that exist in the primary dentition are important factors in
allowing the relatively large permanent incisors to be accommodated in the arch.
✓ The permanent incisors are much more easily aligned in a primary dentition which
has adequate interdental spaces in the anterior region than in a closed type which
has no space.
✓ If there is no space in the primary dentition, the permanent incisors tend to become
crowded
Relationship of spacings in the
primary dental arch to the
alignment of anterior teeth in
the permanent dental arch
(Motchizuki. 1965)

Relationship of the amount of spacings in the primary dentition
to the alignment of incisor teeth in the permanent dentition
(Namba, 1981)
✓ Thus, the presence or absence of the primary
spaces will affect the arrangement of the
permanent incisors in a significant way.

2) Increase of intercanine width
✓ It has been mentioned that the developmental changes during
the initial period of primary dentition are not so significant but
during the incisors' exchange period an obvious change in the
dental arch can be observed.
✓ That is, intercanine width increases markably at the time of
eruption of the maxillary central incisors and the mandibular
lateral incisors.
✓ Moorrees (1959) reported that by the time the lateral incisors
have completed their eruption, the intercanine width has
increased by about 3 mm in each of the maxilla and in the
mandible.
✓ Furthermore, in the maxilla, the intercanine width increases by
another 1.5 mm when the canines erupt.
Changes in the inter-canine width of the dental arches. Solid line: boys; dotted line: girls.
The times of eruption of the permanent teeth are indicated by arrows (Moorrees. 1964).

✓ These changes are important factors which allow the much larger permanent incisors to be
accommodated in the arch previously occupied by the primary incisors.
✓ Therefore, clasps on the cuspids attached to a space maintainer must be cut off at this
time, or should be designed so as to allow the natural increase of intercanine width to
occur unimpeded.

3) Increase of anterior length in the dental arch
✓ Increase in the length of the dental arch in the antero-posterior dimension will also provide
space for the larger permanent incisors to be accommodated.
✓ It is necessary for the permanent incisors to erupt more labially to obtain the necessary added
space.
✓ Actually, the permanent incisors move by about 2 to 3 mm labially from the location of the
primary incisors.
✓ The permanent incisors in the mandible are located occasionally on the lingual side of the
preceeding primary incisors immediately after their eruption.
✓ As the permanent incisors erupt, they also tend to move labially.

✓ In order not to interfere with the natural pathway of labially oriented eruption of the
permanent incisors, one needs to pay careful attention to any abnormal root resorption of
the primary incisors and/ or the use of an incorrectly designed space maintainer at regular
recall appointments, which should occur as early as possible.

4) Change of tooth axis of incisors
✓ One of the characteristic differences between the permanent and
primary teeth is the tooth axis.
✓ In general, primary teeth are very upright but the permanent teeth
tend to incline to the labial or buccal surface.
✓ The interincisal angle between the maxillary and mandibular central
incisors is about 150◦ in the primary dentition, whereas it averages
about 123◦ in the permanent dentition. In other words, the
permanent incisors in both the maxilla and mandible are inclined to
the labial much more than the primary incisors .
✓ This makes the permanent dental arch circumference wider. This is
another advantageous condition for the arrangement of the larger
permanent incisors.
150◦
123◦

5) Ugly duckling stage
✓ Children in the lower classes in elementary schools tend to look unusual during the
time of exchange of their incisors, especially in the upper arch when the permanent
incisors are about to erupt.
✓ The permanent incisors appear to be much too large compared with the primary teeth
with their longitudinal axes flared out like as an inverse "V".
Changes in the axial inclination due to the eruption of the maxillary anterior teeth (Broadbent, 1957)

The central
diastema
decreases
considerably
during eruption of
~ at 8 years and 2
months.
Eruption of .11,12. 7-
year-old girl
central diastema is
almost completely
closed at 11 years.

Frequency and distribution of diastema during the
eruption of the upper central incisors (Sakuma,
1960)
The prognosis of mid-line diastema closure (Sakuma, 1960).

4. Exchange of the lateral teeth (canines and premolars)
✓ The available space for accommodating the lateral teeth is rather limited, as the mesial
surface of the first permanent molar forms its distal limit and the distal surface of the
permanent lateral incisor forms its mesial limit.
✓ Therefore, in order to allow the smooth exchange of the lateral teeth, it is necessary to
have the following conditions.
1) Leeway space
2) Order of exchange of the lateral teeth

1) Leeway space
✓ The sum of the mesio-distal widths of the permanent lateral
teeth is generally smaller than that of the primary lateral
teeth by about 1 mm in the maxilla and about 3 mm in the
mandible. This difference is called the leeway space.
✓ The leeway space is the fundamental factor necessary to
carry out the smooth exchange of the lateral teeth.
✓ The leeway spaces are utilized for the late mesial shift of the
first permanent molars and also for the alleviation of anterior
crowding at the time of exchange in the lateral teeth
segment.

✓ When one observes the size of each of the lateral teeth, the permanent canine is larger
than the primary canine, the first premolar is as large as the primary first molar, and the
second premolar is smaller than the second primary molar.
✓ Therefore, although an exchange of the lateral teeth may be carried out smoothly, there is
crowding as each tooth is exchanged.
Differences in the mesio-distal diameters between primary and permanent lateral teeth. (mm)
(Noda, 1972)

According to Noda, 1972
✓ The distance between the mesial surface of first molar and
the distal surface of the lateral incisor has changed due to the
exchange of the lateral teeth, where the leeway space was
0.60 mm.
✓ The dental arch became crowded transitionally when the first
premolar erupted, but in this case returned to normal by the
time the upper second premolar was fully erupted.
✓ Although this is also very much related to the changing order
of the lateral teeth, the lack of space always happens when a
canine tooth is exchanged in the mandible
crowding

✓ This lack of space is resolved eventually at the time of exfoliation of the second primary molar.
✓ In the case of the vertical type of terminal plane (flush terminal plane) without any spaces in the
primary dental arch, the occlusion of the first permanent molars at the initial contact will be
likely to become rather unstable in the cusp-to-cusp occlusal relationship.
✓ Some of the cases will finally become normal Class I occlusions through the mesial shift of the
lower first permanent molar, which is brought about by the use of the leeway space during the
exchange period of the lateral tooth.
✓ Further, after the exchange of the lateral incisors, the crowding of the anterior tooth region often
observed in the mandible is also alleviated by using the leeway space.

2) Order of exchange of the lateral teeth
✓ It takes about one and a half years to complete the exchange of all the lateral teeth.
✓ Under such difficult conditions with a relatively short time span and limited space in
the arch, for the sake of normal exchange of the lateral teeth, one must consider the
order of exchange as an important factor.

✓ As mentioned previously, because the permanent canine is larger than the primary canine,
crowding is very common immediately after the exchange of the canines.
✓ This phenomenon is more prevalent in the mandible.
✓ If one changes the 3-4-5 pattern, the crowding will be alleviated after the exfoliation of the
second primary molar.
✓ This is the type of exchange in which the normal alignment of the lateral incisors will be the
easiest to accomplish.
✓ By contrast, if the sequence is changed to 4-3-5 or 4-5-3, the leeway space will not be utilized as
efficiently. In such cases, the dentition will become crowded without the leeway space helping
to improve it.

5. Eruption of the second permanent molar
✓ After the exchange of the lateral teeth has been completed, and the dental arch up to the
first molar is established, the second permanent molars will begin to erupt.
✓ In most cases, just prior to the eruption of the second molar, the dental arch length will be
reduced by the eruptive force immediately mesial with the second permanent molar.
✓ With the eruption of the second molar in the permanent dentition, the arch circumference
may become shorter than that of the primary dental arch by the utilization of the leeway
space with the exchange of the second primary molar to the second premolar.
✓ Therefore, it is quite possible that the crowding up to this point may be accentuated if this
trend has already emerged in the last stage of dentitional development.

When the second molars erupt prior to the lateral teeth, there
may be a lack of available space for the teeth which erupt last.

✓ Proximal carious lesions or the early extraction of the second primary molar, which
is not unusual because of the high prevalence of caries for this tooth, will cause
further loss of dental arch space.
✓ This space decreases substantially during the eruption period of the second molar and
will significantly affect occlusal relationships in the molar region.

✓ Finally, there are a few cases in which the eruption of the second molar begins
prior to that of the second premolar.
✓ If the space after the extraction of the second primary molar is not well maintained,
that space will be lost rapidly.
✓ Therefore, sufficient surveillance will be needed during the eruption of the second
molar.
✓ If this is neglected, malocclusion will result in the permanent dentition.

6. Local factors affecting the exchange of teeth
• A smooth exchange from the primary to the permanent dentition is of utmost
importance in occlusal guidance.
• One of the prerequisite conditions for a normal exchange is the condition of the teeth
themselves and the characteristics of the primary dentition that can be regarded as
the prototype of the permanent dentition.
• These prerequisite conditions can be subdivided into two groups: general and local
factors.
Local factors are more clinically related, as follow
1) Dental caries of the primary teeth
2) Factors related to dental abnormalities
3) Factors related to the permanent teeth

1) Dental caries of the primary teeth
(I) A reduction in the mesio-distal width of the tooth crown by dental caries, retained primary tooth
roots, and premature exfoliation or extraction of primary teeth can cause mesial movement of
the adjacent tooth.
• The most conspicuous space loss usually occurs in the first 6 months of the loss of primary
teeth.
Mesial drift of 6 due to the premature loss of the crown of D and E.

(2) Disturbances in the normal root resorption process that are occasionally associated with
infected dental pulp and periodontal tissues will prevent or delay the normal exfoliation of primary
teeth, resulting in the ectopic eruption of the succedaneous teeth
(3) A periapical lesion of the primary tooth can cause abnormality in the direction of eruption and
timing of eruption of a succedaneous tooth

(4) The destruction of the tooth crown or root stump and the premature loss of teeth may cause a
reduction in the occlusal vertical dimension, thus producing an abnormal height of occlusion at the time
of eruption of a succedaneous tooth.
It has been statistically shown that the main cause of deep overbite in the young permanent dentition is
due to the destruction of the tooth crown and premature loss of the primary molar.
There are many root stumps due to gross caries of the primary teeth resulting in premature space loss in
the upper and lower dental arches. An anterior crossbite with deep overbite resulted (8-year-old boy).

2) Factors related to dental abnormalities
(1) The location and direction of eruption of the permanent tooth is easily affected by the existence of a
supernumerary tooth and odontoma.
• Furthermore, this condition wilI adversely influence the root formation of a permanent tooth, resulting in
dilacerations and other pathological abnormalities.
(2) Congenital missing teeth, especialIy in the region of the primary mandibular incisors, wilI cause a
reduction in the circumference of the primary dental arch.
(3) Morphological abnormalities ofthe teeth, e.g. fused teeth, may cause abnormalities in the size and shape
of the dental arch as well as in occlusal relationships.

(1) The impaction of a permanent tooth which can be induced by abnormality in location or tooth axis
of the tooth germ may be associated with the prolonged retention of the primary tooth, resulting in
adverse changes in the developing dental arch.
(2) An ectopic eruption of the first molar may cause an unusual resorption of the roots of a second
primary molar and- quite commonly - early exfoliation of that tooth
(3) The eruption of a permanent tooth maybe retarded by the presence of hyperplasia of the gingival
tissues, either locally or generally.
3) Factors related to the permanent teeth

(4) The early loss of a permaneht tooth, e.g. the loss of a first permanent molar due to dental
caries or the loss of the permanent incisor by traumatic injury may result in the reduction of dental
arch circumference

Diagnosis in occlusal guidance
✓ Treatment of occlusal guidance is carried out during the period when the growth and
development of the entire masticatory apparatus, including dental arch and occlusion,
proceeds from the primary to the permanent dentition.
✓ Therefore, it is important to make a precise diagnosis regarding the various factors that
influence the growth of the jaws and the dentition, or even the growth of an individual
tooth.
✓ It is also important to set up a long term treatment plan.

1. Chief complaint
2. Systematic examination (by interview and inspection)
3. Facial morphology (by inspection and palpation)
4. Oral cavity -1) Dental age
2) Soft tissues (by inspection and palpation)
3) Teeth (by inspection, palpation and radiographic examination
5. Occlusion (by inspection and dental model) -1) Midline
2) Occlusion
3) tooth size
4) Size and shape of the dental arch
5) Mixed dentition analysis
6. Radiographs
1) Panoramic Tomographic Radiography
2) Occlusal Radiographs
3) Bite-wing Radiographs
4) Cephalometric Radiographs
7. Mixed dentitional space analysis

1. Chief complaint
✓ Ask → about the chief complain of dental arch and occlusion the chief complaint of the patient
or parents.
✓ The treatment of occlusal guidance usually begins at an early age, when abnormalities of the
dental arch and occlusion have not been completely defined.
✓ Therefore, it is most important to explain the necessity of the treatment to the patient and his/
her parents in a sufficiently detailed manner.
✓ If there is good mutual understanding between the patients and their dentist, it is relatively easy
to communicate the need for occlusal guidance.

2. Systematic examination (by interview and inspection)
2) Family history
✓ We must first confirm any related occlusal abnormalities in the patient's family history.
✓ Also, the presence of destructive oral habits or nasopharyngeal disease in the patient
must be confirmed.
✓ This information also is useful when one judges whether the occlusal disharmony is
environmental or hereditary in origin.
1) Systemic diseases
✓ It is important for the dentist to judge the relevancy of systemic diseases to oral
abnormalities, particularly in relation to the continuity of treatment during the curative
period.
✓ Poor cooperation of the child patient in the presence of systemic diseases is often
encountered.

3. Facial morphology (by inspection and palpation)
✓ It is helpful to know if any occlusal abnormality is due to local factors or skeletal conditions.
✓ Even though a cephalogram might be the best aid towards a precise diagnosis.
✓ An examination of the facial profile by inspection and palpation can often help to determine
the nature of the problem.

4. Oral cavity
1) Dental age
▪ Inspection of the number and status of eruption of the permanent teeth in the oral
cavity can determine the patient's dental age.
▪ By comparing it with the chronological age of the patient, one can evaluate the
developmental status of the child's dental arch and occlusion.
▪ A treatment plan for occlusal guidance should be developed in harmony with the stage
of development of each patient.

2) Soft tissues (by inspection and palpation)
• The muscular forces from the surrounding soft tissues exert a significant influence on the
structure of the dental arch and occlusion.
• The position of the lips and tongue are related largely to the degree of over-jet and over-bite
of the anterior teeth.
• The structure of the palate is also strongly related to the morphology of the dental arch.

3) Teeth (by inspection, palpation and radiographic examination)
✓ The presence of defects or dental caries, the number of teeth and the structure of the teeth should
be carefully examined.
✓ one should pay attention to the degree of eruption of the second molars and the tooth axis of the
canine tooth germs.

5. Occlusion (by inspection and dental model)
1) Midline
2) Occlusion
3) Tooth size

1) Midline
✓ The examination of the midline should be undertaken with the jaws in opened and closed positions.
✓ This is very important when the presence of premature contact exists. In the case of a cross-bite, the
diagnosis of any midline deviation is helpful to determine whether the cross-bite is bilateral or unilateral.
2) Occlusion
✓ Should be carefully and separately determined in the incisor, the canine, and the molar regions.
✓ In the incisor region → the extent of the over-bite and over-jet must be examined carefully.
✓ In the canine region → it is important to check whether or not the central axis of the upper canine coincides
with the interproximal mid-point between the mandibular canine and the primary first molar.
✓ The standard of examination in the molar region is to use the Angle's classification of the first permanent
molars and the terminal plane of the second primary molars.

3) Tooth size
✓ The measurement of the mesio-distal widths for every individual tooth on the study model should be
done with a pair of sliding calipers.
✓ The size of these teeth can be judged by computing the standard score, which is the ratio of the
difference between the measured value and the mean value of the population to its standard deviation.
✓ This value is indicative of the variability of tooth size in the form of a standard deviation.
✓ To know the divergence between the size of the permanent teeth and their preceding primary teeth is
of great value, but one has to wait until the mixed dentition stage before one can have relatively
accurate and practical predictions of the size of the unerupted permanent teeth.

✓ The measurement of the size of the dental arch is carried out by measuring its length and width with a
pair of sliding calipers.
✓ Just as with the size of the teeth, the calculation of standard scores for these measurements can be a
useful evaluative tool.
✓ The shape of the dental arch can be evaluated by inspection.

6. Radiographs
1) Panoramic Tomographic Radiography
• Useful in evaluating the overall condition of the oral hard tissues such as number, location, and
developmental stages of teeth as well as abnormalities of the jaws.
• It is desirable to take the panoramic tomography radiographs periodically according to the developmental
stages of the dental arch
2) Occlusal Radiographs
• Used for detecting the presence of supernumerary and impacted teeth.
3) Bite-wing Radiographs
• The relation of the first permanent molars to the terminal plane of the primary dentition can be diagnosed
with bite wing radiographs.
4) Cephalometric Radiographs
• The cephalometric radiograph is an important diagnostic aid to determine accurately the relationship
between facial structure and dental occlusion.
• It is particularly useful in determining whether any malocclusion is skeletal or dental in origin.

7. Mixed dentitional space analysis
✓ There are relatively high correlations between each tooth class in the permanent
dentition.
✓ These significant correlations can be utilized to estimate the tooth widths of unerupted
permanent teeth, with a certain level of probability, from the dimensions of the
permanent teeth which have erupted.
✓ Therefore, it is possible to diagnose if the space present in the dental arch due to the early
loss of the primary teeth will be adequate to accommodate the unerupted succedaneous
teeth.
✓ Or, the tooth size of the permanent lateral teeth may be compared with the lateral teeth
group in the primary dentition. This is called the mixed dentition space analysis. It is one
of the very important diagnostic methods in occlusal guidance.

The space analysis of the mixed dentition consists of two steps.
✓ First of all, one estimates the sum of tooth widths of the unerupted permanent lateral teeth
✓ second --based on this estimated value--one analyses the difference with the available space that
exists in the dental arch.
(Armamentarium needed for the mixed dentition analysis)

1) Estimation of the sum of the tooth widths of the permanent lateral teeth
2) Space analysis of the mixed dentition

1) Estimation of the sum of the tooth widths of the permanent lateral teeth
✓ When one estimates the sum of the tooth widths of the unerupted permanent lateral teeth,
it is common to refer to the regression equation developed by Ono (1960) for Oriental
children and the probability chart by Moyers (1976) for Caucasian children.

(1) Estimation using the regression equation by Ono (1960)

(2) Estimation by the Moyers' probability chart

Advantages of moyer’s analysis:
✓ It can be completed in the mouth as well as on casts, and it may be used for both arches.
✓ The analysis is based on a correlation of tooth size; one may measure a tooth or a group of teeth and
predict accurately the size of the other teeth in the same mouth.
✓ The mandibular incisors, because they erupt early in the mixed dentition and may be measured
accurately, have been chosen for measurement to predict the size of the upper, as well as the lower,
posterior teeth.

Tanaka and Johnston Analysis.
✓ The Tanaka and Johnston method of arch-length analysis is a variation of Moyers' analysis
except that a prediction table is not needed.'

✓ Irwin, Herold, and Richardson reviewed the various methods of mixed dentition analysis.
✓ They concluded that the Hixon and Oldfather method is more accurate and any error involves a
consistent underprediction of tooth size, which is of less clinical significance than the overprediction
of tooth size, as seen in all the other methods.
Disadvantage - It is more cumbersome.

Hixon and Oldfather analysis

➢ Moyers claimed that, for the measure of mandibular incisors alone, 95% of the dentitions of patients
with a combined width of canine and premolar teeth within 1 mm of the predicted value should be
clinically acceptable.
➢ Therefore the Tanaka and Johnston analysis provides significant clinical acceptability with a minimal
amount of time and effort.

✓ Another particularly valuable study model analysis is the Bolton analysis.
✓ This analysis addresses tooth mass discrepancies between the maxillary and mandibular
arches.
✓ It can be used to compare the sum of the mesiodistal widths of the 12 maxillary teeth with
that of the 12 mandibular teeth, first molar to first molar, and to compare the 6 maxillary
teeth with the 6 mandibular teeth, canine to canine.
✓ The Bolton analysis ratio is as follows:
(Sum mandibular)/(Sum maxillary) x 100 = Tooth mass ratio

Huckaba Analysis
✓ Recommended by Huckaba G.W. 1964.
✓ Compensates for radiographic enlargement of tooth image in periapical film.
✓ It is based on the assumption that degree of magnification for a primary tooth will be the same as
that of its underlying permanent successor on the same film.

✓ When a significant discrepancy with these ratios is noted, the clinician must assess where
the tooth mass problem is located and decide on the best method to resolve it.
✓ It is not always an easy matter to detect a problem.
✓ A common example is smaller than normal maxillary lateral incisors.
✓ Depending on the size of the discrepancy and the patient's overall malocclusion, two
methods that might be used to resolve this problem include slenderization of the
mandibular anterior teeth or bonding to increase the mesiodistal width of the lateral
incisors.

Space
analysis
of the
mixed
dentition

(7) Diagnosis of available space:
• Finally, for the left and right sides in the upper and lower arches, the amount of space
at the incisor region and the amount of space at the lateral teeth region are added to
determine the amount of space available for each quadrant of the arch.
✓ As a convenience for space analysis, a mixed dentition analyzer is available with a built-in
computing program for space analysis.
✓ The measurements follow a specific order.
✓ By using this tool one can carry out the necessary analysis with an automatic print-out.

Treatment plan in occlusal guidance
a) Space maintenance
b) Timed extraction

PREVENTIVE MANAGEMENT OF THE DEVELOPING OCCLUSION
Planning for space maintenance
✓ Ideally, as the occlusion develops from the primary dentition through the transitional (or mixed)
dentition to the permanent dentition, a sequence of events occurs in an orderly and timely fashion.
✓ These events result in a functional, esthetic, and stable occlusion.
✓ When this sequence is disrupted, however, problems arise that may affect the ultimate occlusal status
of the permanent dentition.
✓ When such disruptions do occur, appropriate corrective measures are needed to restore the normal
process of occlusal development.
✓ Such corrective procedures may involve some type of passive space maintenance, active tooth
guidance, or a combination of both.

General factors influence the development of a malocclusion:
1. Abnormal oral musculature.
2. Oral habits.
3. Existing malocclusion
4. Stage of occlusal development
Forces that act on a tooth to maintain its relationship
in the arch. If one of these forces were removed, as
would be the case if a tooth mesial to the tooth shown
were extracted, forward tipping and mesial drifting
would occur.
Mcdonald and avery’s DENTISTRY FOR THE CHILD AND ADOLESCENT: first south asia edition

1. Abnormal oral musculature.
✓ High tongue position coupled with a strong mentalis muscle may damage the
occlusion after the loss of a mandibular primary molar.
A collapse of the lower dental arch and distal drifting of the anterior segment will
result.
2. Oral habits.
✓ Thumb or finger habits cause abnormal forces on the dental arch and are
responsible for initiating a collapse after the untimely loss of teeth.
Occlusal GuidanceinPediatricDentistry, Minoru Nakata, Stephen H.Y. Wei: ISBN0-912791-63-2

3. Existing malocclusion.
✓ Arch-length inadequacies and other forms of malocclusion, particularly class II division 1,
usually become more severe after the untimely loss of mandibular primary teeth.
4. Stage of occlusal development.
✓ In general, more space loss is likely to occur if teeth are actively erupting adjacent to the
space left by the premature loss of a primary tooth.

Factors are important when space maintenance is considered after the untimely loss of
primary teeth.
1. Time elapsed since loss.
2. Dental age of the patient.
3. Amount of bone covering the unerupted tooth.
4. Sequence of the eruption of teeth.
5. Delayed eruption of the permanent tooth.
6. Congenital absence of the permanent tooth

1. Time elapsed since loss
If space closure occurs, it usually takes place during the first 6 months after the extraction. When a
primary tooth is removed and all factors indicate the need for space maintenance, it is best to insert
an appliance as soon as possible after the extraction.
2. Dental age of the patient.
✓ The chronologic age of the patient is not as important as the developmental age.
✓ Cron et al found that teeth erupt when three fourths of the root is developed, regardless of the
child' s chronologic age.
✓ Several studies have indicated that the loss of a primary molar before 7 years of age
(chronologic) will lead to delayed emergence of the succedaneous tooth, whereas the loss after 7
years of age leads to an early emergence. The magnitude of this effect decreases with age.
✓ In other words, if a primary molar is lost at 4 years of age, the emergence of the premolar could
be delayed by as much as 1 year; emergence will occur at the stage of root completion.
✓ If the same primary molar is lost at 6 years of age, a delay of about 6 months is more likely;
emergence will occur at a time when root development approaches completion.

3. Amount of bone covering the unerupted tooth.
✓ Predictions of tooth emergence based on root development and the influence of the time of the primary
tooth loss are not reliable if the bone covering the developing permanent tooth has been destroyed by
infection.
✓ In such a situation the emergence of the permanent tooth is usually accelerated. If there is bone covering
the crowns, it can be readily predicted that eruption will not occur for many months; insertion of a space-
maintaining appliance is indicated.
✓ A guideline for predicting emergence is that erupting premolars usually require 4 to 5 months to move
through 1 mm of bone as measured on a bite-wing radiograph.
4. Congenital absence of the permanent tooth.
✓ If permanent teeth are congenitally absent, the dentist must decide whether to hold the space for many
years until a fixed replacement can be provided or to allow the space to close.

5. Sequence of the eruption of teeth.
✓ The dentist should observe the relationship of developing and erupting teeth adjacent to the space created by
the untimely loss of a tooth.
✓ A similar situation exists if the first primary molar has been lost prematurely and the permanent lateral incisor
is in an active state of eruption.
✓ The eruption of the permanent lateral incisor will often result in a distal movement of the primary canine and
an encroachment on the space needed by the first premolar.
✓ This condition is frequently accompanied by a shift in the midline toward the area of the loss. In the
mandibular arch a "falling in" of the anterior segment may occur and an increased overbite may result.
6. Delayed eruption of the permanent tooth.
✓ It is not uncommon to observe partially impacted permanent teeth or a deviation in the eruption path that will
result in abnormally delayed eruption.
✓ In cases of this type it is generally necessary to extract the primary tooth, construct a space maintainer, and
allow the permanent tooth to erupt and assume its normal position.

Factors related to arch-length adequacy
✓ Before placing space maintainers or starting tooth movement, the dentist must thoroughly evaluate
arch length.
✓ This is particularly important during the primary and mixed
dentition periods.
✓ Regardless of the arch-length analysis method used, several factors
other than linear arch length and tooth size must be considered.
✓ First, the position of the lower incisors over basal bone must be
determined. If the teeth are retroclined, one may obtain additional
arch length by placing them in a more normal axial inclination.

✓ If the lower incisors are near their upper limit when measured to the mandibular plane
on a cephalogram, further flaring or anterior advancement would jeopardize the
periodontal support of these teeth.
✓ Also, the degree of crowding and amount of space needed to correctly align the
anterior segment must be determined.
✓ Generally, every overlapped contact will require at least 1 mm or more of space for
correction, depending on the severity of crowding.

✓ Using radiographic measurements, prediction charts, or combinations of the two, one
should determine the size of the unerupted premolars and canines.
✓ In some instances, unusually large permanent teeth will necessitate removal of teeth
because of the significant tooth mass/arch-length discrepancy.
✓ The depth of the curve of Spee may also influence available
arch length.
✓ According to Andrews, the ideal occlusion will have a nearly
flat or very slight curve of Spee.’
✓ When leveled, the teeth will require more linear space than
they occupied before.
✓ Generally, 1 mm of linear space is required per side for
every millimeter of the depth of the curve of Spee.

Use of leeway space
✓ If the leeway space as described by Nance is not used, the total arch length will be decreased
further as the permanent molars shift mesially.
✓ Whether this space should be maintained with holding arches depends on the space requirements
as determined from an arch-length analysis.
✓ In some instances, holding leeway space may allow the permanent premolars and canines to erupt
and still provide some space to alleviate anterior crowding.
✓ If the leeway space is not held, future orthodontic treatment may require premolar extractions to
allow the anterior segment to be aligned.

• Moorrees reported that the average arch length of an individual is smaller at 18 years of age than
at 3 years of age.
• This is the result of the decrease in maxillary and mandibular dental arch length that occurs
between 10 and 14 years of age, caused by the exchange of primary molars for the first and
second premolars.

✓ Dimensional changes for dental arch length, circumference, and intermolar and
intercanine widths during childhood and adolescence have been compiled by Moorrees.
Average dimensional dental arch changes from age 6 to 18 years for maxillary and
mandibular arches are as follows:

SPACE MAINTENANCE
✓ Space Maintenance for the First and Second Primary Molar and the Primary
Canine Area
✓ Loss of the Second Primary Molar Before Eruption of the First Permanent Molar
✓ Space Maintenance for the Primary and Permanent Incisor Area
✓ Space Maintenance for Areas of Multiple Tooth Loss

Clinical Disposition Guidelines For Various Dental Arch Space
Conditions Resulting From Overall Mixed Dentition Space Appraisal

Space Maintenance for the First and Second Primary Molar and the Primary
Canine Area
The Band and Loop space Maintainer
✓ It is easy and economical to make, takes little chair time, and adjusts easily to accommodate
the changing dentition.
✓ However, it does not restore chewing function and will not prevent the continued eruption of
the opposing teeth.

✓ The stainless steel crown and loop maintainer may be used if the posterior abutment tooth
has extensive caries and requires a crown restoration or if the abutment tooth has had vital
pulp therapy, in which case it is desirable to protect the crown with full coverage.
✓ A piece of 0.036-inch steel wire is used to prepare the loop.
✓ The advantages of the crown and loop maintainer are similar to those of the band and loop.
✓ Because it is difficult to remove the crown to make adjustments in the loop, some dentists
prefer to adapt a band over a cemented crown restoration and construct a conventional
band and loop appliance.

✓ The loss of the second primary molar will usually have less effect on the teeth in the
anterior segment than the loss of a first primary molar.
✓ However, an irregularity may develop in the permanent molar relationship.
✓ Early loss of the second primary molar is invariably followed by mesial drifting of the first
permanent molar and possible impaction of the second premolar. Also a maxillary molar
often will rotate mesial in.

Occlusal rest in band and loop
✓ A band and loop may require a vertical projection in which the loop contacts the
abutment tooth.
✓ This occlusal rest can prevent tipping and can prevent the anterior portion of the loop
from sliding below the proximal height of contour, which can lead to the wire's
embedding in the gingival tissue several weeks or months later.

Primary canine loss…??
✓ Most often due to ectopic eruption of permanent lateral incisors, early loss of a mandibular canine is a
significant indicator of a tooth size- arch size discrepancy.
✓ Unilateral loss of lower primary canine is frequently followed by a shift in the dental midline toward the
side of tooth loss, lingual collapse of the incisor segment and possibly depending of the bite.
✓ If ectopic eruption involves bilateral loss of both lower primary canine, pronounced lingual inclination
and drifting of the permanent incisors, deepening of the overbite, increased overjet and significant loss of
arch perimeter are likely to be the alignment results.

✓ If one primary canine is lost during incisor eruption, it may be desirable to extract the
contralateral primary canine to help maintain arch symmetry.
✓ When the loss of the primary canine occurs prematurely and there has been no shift in the
midline or space closure, a band and loop or a lingual arch with a spur can be used.
✓ The first primary molar is the abutment tooth if a band and loop is made. If the permanent
molars can be banded, the lingual arch is probably the preferred appliance.

✓ The ectopic loss of maxillary primary canine occurs less frequently than does mandibular
loss, given more favorable space adjustment for incisor liability.
✓ When it occurs, ectopic loss of a maxillary primary canine typically reflects a very distal
eruptive displacement of the permanent lateral incisors and not necessarily a significant
tooth mass problem.
✓ Early loss of maxillary primary canine is an indicator for early orthodontic treatment with an
understanding that child is a definite candidate for comprehensive orthodontic intervention.

• In the mixed dentition, a passive soldered lingual arch is almost always the appliance of choice
in the mandibular arch → especially if the permanent mandibular incisors exhibit crowding.
• Also, the upper lingual arch (Nance appliance) or the lower lingual arch is the appliance of
choice when bilateral space loss is present or when leeway space must be preserved.
• The use of unilateral and bilateral band and loop maintainers is not indicated to manage leeway
space; however, bilateral band and loop maintainers are needed before the eruption of the
permanent incisors.
Mcdonald and avery’s DENTISTRY FOR THE CHILD
AND ADOLESCENT: first south asia edition

Loss of the Second Primary Molar Before Eruption of the First Permanent Molar
✓ Mesial movement and migration of the first permanent molar often occurs before
eruption in instances of premature loss of the second primary molar.
✓ This is one of the most difficult problems of the developing dentition to confront the
pediatric dentist.
✓ Use of a space maintainer that will guide the first permanent molar into its normal
position is indicated.

The Distal Shoe Appliance
✓ Roche has advocated a crown and band appliance with a distal intragingival extension.
✓ This appliance or modifications of it may be used to maintain space or, in some instances, to
influence the active eruption of the first permanent molar in a distal direction.

✓ It is not necessary for the distal extension to be in direct contact with the permanent molar
unless the tooth has already moved mesially.
✓ If the mesiodistal dimension of the second premolar has been duplicated in the appliance,
the length of the loop will be correct.
✓ The depth of the intragingival extension should be about 1.0 to 1.5 mm below the mesial
marginal ridge of the molar, or just sufficient to "capture" its mesial surface as the tooth
erupts and moves forward.

✓ After the molar has erupted, the intragingival extension is removed.
✓ If the appliance is to be used as a reverse band and loop space maintainer, it may be
necessary to add a supragingival extension to prevent the molar from tipping over the
wire.

Contraindicate the use of the distal shoe appliance.
✓ If several teeth are missing, abutments to support a cemented appliance may be absent.
✓ Poor oral hygiene or lack of patient and parental cooperation greatly reduces the possibility
of a successful clinical result.
✓ Certain medical conditions, such as blood dyscrasias, immunosuppression, congenital heart
defects, history of rheumatic fever, diabetes, or generalized debilitation,

Histologic studies show that….
The distal shoe implant never becomes totally lined with epithelium and is
associated with a chronic inflammatory response.
Mcdonald and avery’s DENTISTRY FOR THE CHILD AND
ADOLESCENT: first south asia edition

✓ Two possibilities for treatment exist:
(1) allow the tooth to erupt and regain space later or
(2) use a removable or fixed appliance that does not penetrate the tissue but places pressure on
the ridge mesial to the unerupted permanent molar.
✓ Carroll and Jones have reported three cases in which a pressure appliance, removable or
fixed, was used to guide the permanent molar as it erupted.
✓ If several teeth are missing, the removable appliance can also be designed to restore function
and prevent supra-eruption of opposing teeth.
What to do when distal shoe is contra-indicated…./
Mcdonald and avery’s DENTISTRY FOR THE CHILD AND ADOLESCENT: first south asia
edition

Space Maintenance for the Primary and Permanent Incisor Area
✓ Some dentists believe that space closure rarely occurs in the anterior part of the mouth, but
this is not true; each case must be critically evaluated.
✓ It is important to consider the occlusion and the degree of spacing, if any, between the
anterior teeth.
✓ If the anterior primary teeth were in contact before the loss or there is evidence of an arch-
length inadequacy in the anterior region, a collapse in the arch after the loss of one of the
primary incisors is almost certain
edition

Removable Partial Dentures.
✓ Even when spacing is present, it may be desirable to construct a partial denture or a
fixed appliance to reproduce a desirable esthetic appearance, to reestablish function, or
to prevent abnormal speech and tongue habits.
✓ Acrylic partial dentures have been used successfully to replace maxillary anterior
primary teeth.
✓ It is unwise to place a removable partial denture, however, if an uncontrolled dental
caries problem exists or if the child's mouth will not be kept clean enough to reduce the
possibility of dental caries activity.
edition

Fixed Appliances.
✓ If a fixed appliance is required, one approach is to attach the anterior replacement teeth to a
0.040- or 0.045-inch stainless steel wire framework retained with bands or crowns on the
second primary molars.
✓ If the first primary molars are present, an indirect retainer may be placed on the occlusal area
to prevent the wire from flexing.
✓ One can also obtain additional stabilization by using a Nance button or covering the ridge
with dental acrylic resin.
edition

✓ The loss of anterior permanent teeth requires immediate treatment by the dentist if
intraarch changes are to be prevented.
✓ Within a few days after the loss of a tooth as a result of trauma or the extraction of a
severely traumatized tooth, the teeth adjacent to the space will begin to drift, and often
within a few weeks several millimeters of space will be lost.
✓ Rather than allow the extraction area to heal and regain normal contour, the dentist
should take an impression at the time of the initial appointment or within a few days.
✓ The temporary appliance is constructed and inserted as soon as possible after the loss to
prevent space closure.
In case of loss of permanent teeth
edition

In case of space close in anterior region…??
✓ If any degree of space closure has occurred, the space should be regained, if possible,
before the construction of a space maintainer.
✓ A partial denture—activating appliance can be used successfully in this procedure if there
is no need for bodily movement of teeth.
✓ Helical finger springs of 0.018- to 0.022-inch wire are contoured to the
teeth to be moved.
✓ The wire is placed as far cervically as possible. The finger springs are
adjusted about 1 to 1.5 mm every 3 to 4 weeks.
✓ This procedure avoids excessive pressure on the teeth and allows their slow
and regular movement.
edition

✓ Neither the labial bow nor the palatal acrylic material should interfere with the teeth as
they are being moved.
✓ Otherwise the space will not open. After the space is regained, a tooth may be added or a
new retainer with a replacement tooth can be used until a fixed replacement is made.

Space Maintenance for Areas of Multiple Tooth Loss
✓ The multiple loss of primary molars in the primary or mixed dentition will invariably
lead to……
severe mutilation of the developing dentition unless an appliance is constructed to
maintain the relationship of the remaining teeth and to guide the eruption of the
developing teeth.

Consequences of multiple tooth loss
✓ Crossbite in the first permanent molar area and subsequent anterior drifting of the
permanent molars have been observed to occur after the loss of the maxillary primary
molars.
✓ Reduced masticatory function is undesirable from a nutritional standpoint.
✓ The accumulation of plaque material and food debris after the loss of normal cleansing
function will often result in increased dental caries activity and gingival inflammation.

Acrylic Partial Denture.
✓ The acrylic partial denture has been used successfully after the multiple loss of teeth in the
mandible or the maxillary arch.
Indication → bilateral loss of more than a single tooth, can be readily adjusted to allow for the
eruption of teeth.
✓ If artificial teeth are included on the denture, an essentially normal degree of function will
be restored.

Advantage
✓ Contoured clasp type is acceptable from the standpoint of simplicity of
construction, functional requirements, and cost to the patient
Disadvantage
✓ Parental and patient cooperation are imperative
✓ breakage of the appliance is a potential factor, since the pediatric patient may not
exercise the necessary care.

✓ Retention is important particularly during the initial period of insertion.
✓ Stainless steel wire clasps are contoured for the primary canines, and 0.036-inch steel wire
rests are contoured for the molars.
If the permanent incisors are in an active state of eruption, it is desirable to remove the
clasps after the child has become accustomed to wearing the appliance to allow the
distal drifting and lateral movement of the primary canines and alignment of the
permanent incisors.

It is unlikely that there will be additional intercanine expansion in the older child.
Therefore the fixation of the primary canines before the eruption of the permanent
successors will have no adverse effect on the dental arch.

Situation where→ the loss of one or both of the second primary molars occurs a short time before
the eruption of the first permanent molars, the acrylic removable appliance may be considered.
✓ Immediate use of an acrylic partial denture with an acrylic distal shoe extension has been
advocated by Starkey, and such a device has been employed successfully to guide first
permanent molars into position .
✓ The tooth to be extracted is cut away from the stone cast,
and a depression is cut into the stone model to allow the
fabrication of the acrylic extension.
✓ The acrylic will extend into the alveolus after removal of the
primary tooth.
✓ The extension may be removed after the eruption of the
permanent tooth.

Passive Lingual Arch.
✓ Choice after the multiple loss of primary teeth in the maxillary or in the
mandibular arch.
✓ Although it does not satisfy the requirements for restoring function, the
appliance has many advantages that outweigh this fact.
✓ The use of the lingual arch essentially eliminates
the problem of patient cooperation.
✓ With properly fitted bands and a well-made
appliance, there should be no problems with
breakage or retention and no concern about
whether the child is wearing it.
Mcdonald and avery’s DENTISTRY FOR THE
CHILD AND ADOLESCENT: first south asia
edition

✓ In contouring the arch wire, one should allow for the path of eruption of the
premolar and canines so that the arch wire will not interfere.
✓ Should this occur, the appliance will need to be remade or altered.
✓ Where possible, an ideal anterior arch form should be constructed so that the
incisors have an opportunity for alignment.

Full Dentures for Children.
✓ It is occasionally necessary to recommend the extraction
of all the primary teeth of a preschool child.
✓ Although this procedure was more common in the
prefluoridation era, some children even today must have
all of their teeth removed because of widespread oral
infection and because the teeth are unrestorable.
✓ Preschool children can wear complete dentures
successfully before the eruption of permanent teeth

Loss of the First Permanent Molar
➢ Loss of the First Permanent Molar Before the Eruption of the Second
Permanent Molar.
➢ Loss of the First Permanent Molar After the Eruption of the Second
Permanent Molar.

✓ A carious lesion may develop rapidly in the first permanent molar and
occasionally progress from an incipient lesion to a pulp exposure in a 6-month
period.
✓ The loss of a first permanent molar in a child can lead to changes in the dental
arches that can be traced throughout the life of that person.
✓ Unless appropriate corrective measures are instituted, these changes include…
Diminished local function
Drifting of teeth
Continued eruption of opposing teeth

Loss of the First Permanent Molar Before the Eruption of the Second Permanent
Molar.
✓ Although it is possible to prevent overeruption of a maxillary first permanent
molar by placing a lower partial denture, there is no completely effective way to
influence the path of eruption of the developing second permanent molar other
than the use of an acrylic distal shoe extension on a partial denture.
✓ The second molar will drift mesially before eruption when the first permanent
molar has been extracted.
✓ Repositioning this tooth orthodontically is possible after its eruption. However,
the child must then be considered for prolonged space maintenance until the
time when a more permanent tooth replacement can be inserted.

✓ If the first permanent molars are removed several years before the eruption
of the second permanent molars, there is an excellent chance that the second
molars will erupt in an acceptable position.
✓ However, the axial inclination of the second molars, particularly in the lower
arch, may be greater than normal.

✓ The decision as to whether to allow the second molar to drift mesially or to
guide it forward in an upright position may be influenced by →the presence of
a third molar of normal size.
✓ If there is a question regarding the favorable development of a third molar on
the affected side, repositioning the drifted second molar and holding space for a
replacement prosthesis is usually the treatment of choice.

Loss of the First Permanent Molar After the Eruption of the Second Permanent
Molar
✓ Orthodontic evaluation is indicated, and the following points should be
considered:
✓ Is the child in need of corrective treatment other than in the first permanent
molar area?
✓ Should the space be maintained for a replacement prosthesis?
✓ Should the second molar be moved forward into the area formerly occupied by
the first molar?
✓ The latter choice is often the more satisfactory, even though there will be a
difference in the number of molars in the opposing arch.

If the space should be maintained, this may be accomplished in one of several ways:
1. Cast overlay band and loop
2. Band and loop maintainer with occlusal bar and rest
3. Conventional fixed bridgework
4. Etched-casting, resin-bonded posterior bridge ( modified fixed bridgework)
5. Single-unit implant prosthesis

✓ Another option to consider, however, is autotransplantation of a third
molar into the first molar position.
✓ According to Bauss et al → autotransplantation has become a well-
established treatment modality in cases of early tooth loss or aplasia.
✓ For third molars with partly developed roots, transplantation success
rates have been reported in the range of 74% to 100%.

✓ When there is a slight difference in the timing of the exchange of the anterior teeth
between the right and left sides, a deviation of the midline may also occur.
✓ The other main strategy falling under this category is the management of space
through the timely extraction of primary teeth, based up on an assessment of the
condition of root formation of the succedaneous teeth. This type of the extraction of
sound primary teeth is called "timed extraction".
✓ The normal development of the dentition in these cases can be guided by the timely
extraction of intact primary teeth.
2) Timed extraction

✓ There is a high correlation between the amount of eruption and the
apical growth of the teeth.
✓ The eruption of the successor tooth is usually accelerated just after
the extraction of the preceding primary tooth, provided that more
than one half of the root has formed.
✓ The most appropriate time for the "timed extraction" procedure
should be determined according to the developmental stages of the
succedaneous teeth as observed from radiographs.
✓ Hence, the preservation of the total arch circumference may be
achieved by "timed extraction".
(The amount of root formation at the time of eruption of the lateral
teeth. Usually eruption of a tooth commences when more than half of
its root formation is complete.)

2. Treatment in active occlusal guidance
✓ Active occlusal guidance involves the early detection, interception, and treatment of
abnormal developments in the dental arch and occlusion.
✓ Such abnormalities -- which can be treated in their early stages to good result -- are
associated with….
➢ Ectopic eruption of the permanent teeth
➢ Mesial shift or inclination of the first permanent molars due to the early
loss of primary molars
➢ Exchange errors of the dentition, and anterior or posterior cross bites
Other possible occlusal abnormalities → oral habits, skeletal problems, severe
crowding due to discrepancies between the size of the primary and permanent
teeth, severe tooth and jaw size discrepancies.
Occlusal GuidanceinPediatricDentistry, Minoru Nakata, Stephen H.Y.
Wei: ISBN0-912791-63-2

Active occlusal guidance includes the following specific items:
1) Space regaining
2) Occlusal adjustment at the mixed dentition stage
3) Early detection and treatment of abnormal eruption
4) Early detection, interception and treatment of occlusal disharmony
5) Control of oral habits

1) Space regaining
✓ With cases in which dental decay has caused a premature loss of the primary molars (resulting in a
reduction of dental arch circumference), and the first permanent molar has then shifted or inclined
mesially
The lost space may be regained by an "uprighting" or distal movement of the first permanent molar to its
normal position.

✓ Before treating such a case, one must confirm that the space loss is not caused by a size discrepancy or
disharmony between the dental arch and teeth.
✓ A thorough analysis for any skeletal disharmony, including space analysis, should be undertaken.
If the loss of space is
< 3 mm, this space can
generally be regained
by the distal movement
of the first permanent
molar
Serial extraction
will be the method
of choice for cases
in which the space
loss is 5 mm or
greater.
The border-line cases in which space loss is between 3 - 5 mm, must be carefully
dealt with on a case-by-case basis, using good clinical judgement.

(1) Removable type space regainer
(2) Lingual arch type space regainer
(1) Removable type space regainer
a. Sling-shot type space regainer
b. Screw type space regainer
c. Spring type space regainer
d. Split saddle type space regainer
Note :
• All removable appliances are limited in effectiveness by the degree of
cooperation of the child patient.
• The other important criteria for their success is adequate stability and anchorage
of the appliance.

a. Sling-shot type space regainer (named because of its resemblance to a “Sling-shot”)
✓ From the distal end of this appliance, hooks are attached on the buccal and lingual sides of the first
permanent molar, which needs to be moved distally.
✓ An elastic band is slung between the hooks, and the tension force from the elastic band then produces
the distal movement of the first permanent molar.
✓ The force that acts to produce the distal movement of the tooth is very gentle and physiological:
however, the distal movement is limited to I - 2 mm in distance.

b. Screw type space regainer
✓ An expansion screw can be embedded in the resin base of a removable appliance.
✓ By expanding the screw, distal movement of the first permanent molar is achieved.
✓ The expansion of the screw is performed by the patient once a week.
✓ The first permanent molar can be distalized by the maximum opening width of the screw,
which is about 3 mm.
✓ Further movement can be achieved by using a second appliance with a new screw.

c. Spring type space regainer
✓ The distal movement of the first permanent molar can be achieved through
the force produced by a spring using 0.7 mm wire.

d. Split saddle type space regainer
✓ This appliance is most commonly used in the lower arch.
✓ A distal movement of the first permanent molar is achieved by flattening the bent
portion of the wire connecting the split saddles of the acrylic base plate.
✓ The distal movement is limited to 1-2 mm.
✓ This appliance is contraindicated when no space is present in the mesial aspect of
the first permanent molar.

(2) Lingual arch type space regainer
✓ A distal movement of the first permanent molar is achieved by means of a wire spring,
attached to the lingual arch.
✓ Anchorage is very important in assuring that sufficient force is exerted to move the first
permanent molar distally.
(Lingual arch with spring wire attached.) Occlusal GuidanceinPediatricDentistry, Minoru Nakata, Stephen
H.Y. Wei: ISBN0-912791-63-2

2) Occlusal adjustment at the mixed dentition stage
✓ In some cases, a transient crowding or premature occlusal contact develops in the
exchange process from primary to permanent dentition.
✓ Early intervention and correction of this condition can improve and abort the abnormal
path of development which will then speedily change to a normal stage of development.
✓ Otherwise, the case can become very complicated, requiring more extensive treatment of
the occlusal disharmony in the future.

✓ Occlusal adjustments of the primary teeth are highly effective when→ properly done in a
timely fashion.
✓ The procedures used include judicious incisal and proximal grinding.
✓ By properly grinding the incisal edges or cusp tips of selected anterior occlusal
interferences, premature contacts on biting will be eliminated.
✓ Proximal grinding is the method whereby the temporary crowding that appears at the time
of exfoliation is ameliorated by eliminating the contiguity of the primary teeth.
Occlusal GuidanceinPediatricDentistry, Minoru
Nakata, Stephen H.Y. Wei: ISBN0-912791-63-2

3) Early detection and treatment of abnormal eruption
✓ When a permanent incisor or first molar erupts ectopically in an abnormal
location, it is called "ectopic eruption".
✓ E.g ,when a first permanent molar erupts too mesially, the distal root of the second
primary molar is resorbed.
Occlusal GuidanceinPediatricDentistry, Minoru Nakata, Stephen H.Y. Wei:
ISBN0-912791-63-2

✓ Such cases should be treated by → separation of the adjoining teeth with the
use of a ligature wire or safety-pintype spring.
✓ As the first molar is distalized and uprighted by this procedure, further
eruption can take place, with the tooth usually erupting into its normal
position.

✓ Also, the presence of supernumerary teeth, odontoma or excessively large and
fibrous upper labial frenum should be detected at an early stage, before clinical signs
appear.
✓ The early treatment of such abnormalities will usually restore the developmental
processes of the dental arch and occlusion to their normal conditions.

4) Early detection, interception and treatment of occlusal disharmony
✓ Among various occlusal abnormalities, the frequency of cross-bites and mandibular
prognathism is relatively high.
✓ With cases in which the abnormality is dental in origin, early treatment can usually
produce satisfactory results.
✓ However, if skeletal disharmony exists, the rapid growth of the mandible during the
period of active skeletal growth will increase the abnormal jaw relationship.
✓ Even with these cases, interceptive treatment undertaken at an early age can produce
effective results, greatly alleviating the extent of occlusal abnormality.
Occlusal GuidanceinPediatricDentistry, Minoru
Nakata, Stephen H.Y. Wei: ISBN0-912791-63-2

(1) Molar cross-bite
(2) Anterior cross-bite
(3) Mandibular prognathism
(1) Molar cross-bite
✓ When the first permanent maxillary and mandibular molars first reach their occlusal planes,
they occasionally develop a cross-bite.
✓ Cause = discrepancy in arch width between the upper and lower arches, or may be due to a
difference in bucco-lingual tooth axial inclinations.

✓ In the latter case, the condition can be improved by using cross elastics.
✓ When the cross-bite involves several teeth, one needs to know whether the etiology is dental
or skeletal.
✓ If dental in origin, the use of an appliance -such as a Porter's W appliance or an expansion
appliance like a Coffin spring- to expand the maxillary arch width is usually very successful.

Occlusal guidance

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Occlusal guidance

Similar to Occlusal guidance (20)

More from Dr. Lilavanti vaghela

More from Dr. Lilavanti vaghela (9)

Recently uploaded

Recently uploaded (20)

Occlusal guidance