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Dr. Mohammed Alruby
Preventive orthodontics
Prepared by:
Dr Mohammed Alruby
‫صواب‬ ‫علي‬ ‫دائما‬ ‫انفسهم‬ ‫يرون‬ ‫اشخاص‬ ‫مع‬ ‫نتعايش‬ ‫ان‬ ‫الصعب‬ ‫من‬

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Dr. Mohammed Alruby
Orthodontics: is a branch of science and art of dentistry dealing with prevention, interception and
correction of positional or dimensional dentofacial abnormalities
It has the responsibility to study and supervise the dentofacial growth and development from birth until
maturity
Orthodontic treatment could be divided as follow:
1- Preventive orthodontic treatment
2- Interceptive orthodontic treatment
3- Corrective orthodontic treatment
- Early corrective
- Late corrective
4- Post treatment maintenance or retention and follow up
= Preventive orthodontics may be defined as that phase of orthodontics that employed in recognition and
elimination of potential malocclusions
= Effective preventive measures must be applied as early as possible in the life of child (deciduous and
early mixed dentition)
= Note that prevention of malocclusion in early life din not necessarily prevent development of
malocclusion in later life
= Periodic mouth examination and full diagnostic records are necessary at least every 6 months during
the early mixed dentition because it is very critical phase during which many changes are observed as the
child transformed from deciduous to mixed dentition
Preventive measures consist mainly of the following:
1- Recognition of early deviations from the normal, this requires:
- Accurate diagnosis aided by clinical examination and full diagnostic records done at periodic
interval of 6 months
- High clinical experience and basic knowledge to differentiate between the normal occlusion
and potential malocclusion and predict the growth of dentofacial complex
2- Recognize predisposing factors of malocclusion
3- Recognize the harmful dentofacial habits
4- Classify the malocclusion and advise the needs for orthodontic care
5- Promote and maintain the normal occlusion by:
- Extraction of over retained deciduous teeth, remaining roots and supernumerary teeth
- Using space maintainer when indicated
- Caries control and restoration of caries teeth
- Control of periodontal disease and maintenance of good oral hygiene
6- Refer the child to medical specialist for diagnosis and treatment of systemic conditions
7- Refer the child with cleft palate for maxillofacial surgeon
8- Refer the patient to psychiatric when needed
The child as a patient
= children will accept orthodontic treatment if the purpose for treatment is explained in a simple term that
can understand. Information concerning treatment aims and procedures should be given to the child
without hesitation and under authority, neither give him a great attention nor neglect him
= be familiar with the child and give him some sympathy
= Most children at pre-adolescent age are ready to accept orthodontic treatment, if the orthodontist was
able to establish a sympathetic relationship with the child. The child must not force to treatment but it is
better to postpone treatment until the child feels the needs for treatment

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Dr. Mohammed Alruby
The adolescent patients
15 years old patient frequently consider himself as a man and must has a special management, adolescent
patient may deny, that his teeth needs correction of his teeth and wearing of the appliance. It is very
important to know whether the patient came the office alone, or with friend or forced by his parents
Psycho-dynamics of dentofacial, malformation
= Dentofacial malformation frequently have a psychological impact especially in adolescent patients, this
because of the constant preoccupation with their facial deformity. The psychological disturbances
associated with dentofacial deformity may have more marked effect on patient than that caused by hand
capping of the deformity itself. So the patient must be reassumed from time to time his deformity is being
corrected.
= the psychological disturbance of facially malformed children not only due to reaction of their friends at
school or when playing but also due to the reaction of his family
Families of malformed children react in different ways:
1- They either reject the child or over protect him, both condition will cause an abnormal
psychological behavior
2- The parents may blame each other on the occurrence of malformation
Results: the child also react in different ways:
1- Withdraw himself from the social contact, tend to be alone and usually accept an inferior position
in the society which usually accorded him
2- Other children may use their facial deformity as protective mechanism to get sympathy for other
people. They feel that they must have a special management because of their hand cap
= unfortunately, both behavior may not stop after correction of deformity
= when possible, correction should be done before the school age the dentist should not extract the tooth
without permission of the child, otherwise the child may lose confidence in is dentist and become
uncooperative. If refused extraction refer him to family dentist
Timing of treatment
Timing of preventive orthodontic treatment depends primarily on the presence of conditions that
require an immediate intervention regardless the age of patient however the preventive treatment is usually
carried out during deciduous and early mixed dentition
= serial examination and diagnostic record should be obtained at the following intervals:
1- Before permanent mandibular incisors begins to erupt ---- at 5 years
2- After permanent maxillary incisors begin to erupt --- at 6.5 years
3- After permanent maxillary lateral incisors begins to erupt ---- at 7.5 to 8 years
= the size of the dental arches increases rapidly in females than in males, but the time span of such increase
is shorter in females than males
= Morrees found that, the changes in the arch length and intercanine width are small between 3 and 5
years, as the permanent incisors erupt between 6: 8, the inter-canine width increase about 3mm
= from 4:6 years the arch length is stable, it is gradually increase between 6 and 10 years as a result of
eruption and increase proclination of incisors.
Between 10 and 14 years, the arch length decrease by about 1.5mm in maxilla and 2.5mm in mandible
because the mesial shifting of U and L 6 occupying the leeway space
= shorter after 10 years, the maxillary intercanine width increase by about 2mm due to eruption of U3,
while the mandibular intercanine width decrease slightly
Both arch length and intercanine width may shows slight increase after 14 years

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Dr. Mohammed Alruby
When treatment is recommended:
= potential malocclusion should be treated as early as possible when the condition is observed to interface
with normal growth, development and function or endanger the health of oral tissues
= certain types of malocclusion are self-corrected and require no treatment
Preventive procedures
- Without appliances
- With appliances
A- Preventive procedure without appliances
1- Pre-dental preventive procedures
2- Dental preventive procedures
1- Pre-dental preventive procedures:
Instruct the mother to feed his baby from breast, if the baby feed by bottle the nipple should be long enough
to rest on anterior 1/3 of the tongue. It also should contain small side opening instead of single end hole,
this allow the milk to flow on the dorsum of the tongue and prevent it from being squeezed directly into the
pharynx. By this method the tongue is allowed to functions properly during swallowing which is very
important in normal growth of the jaws, also less air will be swallowed with milk.
2- Dental preventive procedures:
1- Dental caries
= Dental caries makes possible tipping and crowding of adjacent teeth, over eruption of opposing teeth,
decrease in arch length and possible loss of the teeth. Caries should be restored to normal contour.
= Inter-proximal cavities should be prepared and permanently filled in one visit especially in mixed
dentition period, because the rapid loss of space by mesial shifting of the teeth. Permanent teeth lost due
to caries or any other reasons, should be replaced in children as early as possible if malocclusion to be
avoided. Malocclusion can be initiated due to caries or loss of the teeth as the child favor one side for
mastication to avoid chewing on painful caries tooth or hand capping by the lost teeth.
Technique for fluoride application:
The following technique is described by Knutson:
- Clean the teeth thoroughly (only the 1st
application is proceeding by dental prophylaxis)
- Isolate the teeth with cotton rolls
- Dry the teeth with compressed air
- Wet the crown surface with 2 % sodium fluoride solution using cotton applicator
- Allow the teeth to dry for 4 minutes
- Rinse the mouth with water if desired
- The 2nd
, 3rd
, fourth application are made at approximately one-week interval, Solzman found
that malocclusion is more frequent among non-fluorinated ones, this would attribute to the high
caries index and early loss of 6 in children living in areas with non- fluorinated water supply
2- Loss of the teeth and supernumerary:
Loss of teeth:
Space loss following loss of teeth are common in maxilla than in mandible and in poorly developed arch
than in well-developed arch. Well- developed arch shows a little or no space loss after extraction. Lost
teeth should be replaced as early as possible in children if malocclusion to be avoided to prevent the child
from developing an abnormal mandibular posture (bite of accommodation) or bad habits. The space of lost
teeth can be opened or closed according to the condition
Supernumerary teeth:
May cause an abnormal eruption path, malposition, ectopic eruption or even impaction of permanent teeth.
Mesiodens is one cause of median diastema, supernumerary teeth should be removed as early as possible
when detected to allow normal eruption of permanent teeth

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Dr. Mohammed Alruby
3- Infection:
Infected deciduous tooth should not keep in month for the purpose of space retention. The pressure of
inflammatory exudate can deflect the permanent tooth bud causing ectopic eruption or impaction of
permanent teeth.
Shiere et al found that complete exfoliation of permanent tooth bud may result from local inflammation
and suppuration caused by infected deciduous tooth
4- Ankylosed deciduous molars:
Ankylosed deciduous molars should be extracted when permanent successors are present, but when
permanent successors are congenitally absent, the decision in such case depend upon the condition:
- If the arch length is abundant and can accommodate all permanent teeth in a good alignment,
the tooth should be kept
- If the arch length is deficient, the ankylosed tooth should be extracted and the space is utilized
for aligning the teeth
5- Extraction of 1st
permanent molars:
If 1st
permanent molar was caries beyond repair, it may be extracted and the space is utilized for correction
of anterior crowding
The extraction is better done before eruption of 2nd
molar because there will be a great chance for 2nd
molar to erupt forward closing the space of extracted 1st
molar
6- Ectopic eruption:
Orthodontic correction of ectopically erupted teeth is too difficult, so that the prevention of ectopic eruption
is better and easy task, prevention of ectopic eruption can be achieved by:
- Removal of supernumerary teeth
- Correction of malposed teeth
- Closure of spaces of missing teeth either by orthodontic or prosthetic means
- Removal of over retained deciduous teeth
7- Premature contact:
Grinding of the incisal tip of primary canines is useful to permit free lateral excursion of the mandible, to
prevent interference with forward movement of the mandible and to correct the early cross bite
8- Over retained deciduous teeth:
Extraction of over retained deciduous teeth should be performed as indicated by the developmental status
of permanent successors
Panoramic and periapical radiograph are diagnostic
9- Deeply locked 1st
permanent molar:
= may cause resorption of the distal roots and cervical portion of 2nd
primary molars, this can treat either
by disking the distal surface of E to free the 6 or by extraction of E and maintenance the space for 5
= slightly locked 1st
permanent molar:
May freed itself automatically without active treatment or may be treated by separation with brass wire
that pass inter-dentally between E and 6 then twisted and tightened, when become loose it should be twisted
again until complete eruption of 6 takes place.
= locking of 1st
permanent molar under the cervical portion of E is usually associated with general lock
of growth of basal bone and crowding of the teeth.
10- Mouth breathing:
= Preventive measures consisted of elimination of naso-pharyngeal obstruction and construction of oral
screen. It is important to ascertain that the child can breathe through his nose before construction of oral
screen.
= many clinical tests are available, refer the child to an otolaryngologist to remove hypertrophied tissue
before any interceptive measures is taken
11- Recurrent subluxation of the mandible:
May causes occlusal and TMJ disorders when the mandible is easy dislocated as evidenced by recurrent
subluxation, the mouth opening should limit either by interdental elastics applied to fixed appliance or by
using chin cup and occlusal anchorage

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Dr. Mohammed Alruby
12- Abnormal labial Frenum:
Abnormal labial Frenum is one of the causes of median diastema, it should surgically excise before
correction of diastema
13- Tongue tie:
Congenital inferior ankyloglossia is caused by thickened abnormally attached genioglossus muscle which
fix the tongue to the floor of the mouth. Tongue tie causing feeling difficulties in infant, abnormal tongue
function and speech defect ((the sound S and R are affected)) this due to limitation of tongue movements
Healing after surgical removal of tongue tie often leaves an extensive scar which may immobilize the
tongue, so that the operation should be avoided until there is gross functional disturbance. Tongue tie may
disappear after 4 years ago, so that the operation must be carried before this age
14- Orthodontic for hemophiliacs:
= Extraction of the teeth in hemophilic patients is contraindicated when it can be avoided, but if to be done
the child should be hospitalized, multiple extractions of deciduous is done under general anesthesia, blood
transfusion is necessary to supply the child with lacking coagulating factors, if oozing occurs after loss of
deciduous teeth, ice packs, pressure, adrenaline and liquid thrombin should be applied locally
= Removable appliances are the treatment of choice for hemophilic child, impression should be taken in
hospital or in the presence of physician if fixed appliance to be used, avoiding pushing or bands against
gingiva avoiding leaving any sharp edges of the wire. Sticky wax should use to cover any sharp points in
the appliance, it preferable to use ligating elastic ring instead of ligature wire, direct bond instead of bands
B- Preventive procedures with appliance:
1- Mouth protectors:
Should be wear by children playing contact sports to avoid accidental fracture of the teeth and injuries of
soft tissues
Requirements of mouth protectors:
- Should not interfere with normal functions
- Should give maximum protection of the teeth
- Should have minimum and maximum strength
- Should be fit properly over the entire dental arch
- Should occupies little space as possible
- Should be light and easily adjusted
- Should not impinge the soft tissues
- Should not disturb the muscle function
- Should not expensive
Construction of mouth guard:
= an alginate impression material is taken and the cast is poured, a wax bite is taken with the teeth in full
occlusion.
= the appliance is fabricated from rubber with thermoplastic lining, latex or acrylic shelf with soft lining,
the appliance is worn on maxillary arch
= fixed orthodontic appliance should not remove from construction of the mouth protector, but impression
is taken with fixed appliance on place and mouth protector is constructed to fit the appliance, so it will
provide a double protection for the teeth and fixed appliance
2- Treatment of injured teeth:
Accidental traumatic injuries of maxillary anterior teeth is common and frequently occurs with protruding,
the prognosis is more favorable when the root is not completely formed
Direct blow may cause fracture of the crown while indirect blow is abler to causes fractures of the root
especially when completely formed.
Sequelae:
a- The crown may fracture with or without pulp exposure
b- Root may be fractured longitudinally or transversely with or without fracture of alveolar process

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Dr. Mohammed Alruby
c- Devitalization of the teeth is a common sequela but there may be a chance for pulp survival
especially when the root is not completely formed. So that the tooth should be kept under periodic
observation for any change of the color
d- Internal or external root resorption especially when the root is completely formed
e- Infections
f- Looseness of the teeth
g- Ankylosis
Treatment:
a- Crown fracture without pulp exposure ---- jacket crown
b- Crown fracture with pulp exposure ------- pulp capping or pulpotomy or pulpectomy and jacket
crown
c- Root fracture: usually heals by cemental deposition
Fracture of apical third with pulp devitalization --– apicectomy + endodontic treatment + jacket crown
d- Fracture of alveolar process; manual reduction and immobilization for at least six weeks
e- Looseness of the teeth ------ immobilization by acrylic splint. Self-cure acrylic splint is made directly
over the teeth including the sound teeth on both sides, the patient is asked to bring the teeth into
full occlusion with the splint in place. Then the splint is removed, allowed to set, trimmed and
polished, the cemented on maxillary teeth for 6 weeks at least.
Wiring of the loose teeth is not effective and may causes and may causes undesirable tooth
movements
Space control in deciduous and mixed dentition
= diagnosis of space deficiency problem: mixed dentition analysis
= diagnostic aids:
study cast
panoramic radiograph
periapical radiograph
bitewing radiograph
= premature loss of deciduous teeth, can causes malocclusion of permanent teeth, the deciduous teeth act
to preserve the mesio-distal and vertical spaces for their permanent successor. In determining the need for
space maintainer, careful prediction of growth and development of dentition and basal bones is necessary.
= abnormal resorption pattern of deciduous teeth may be an indication for arch length inadequacy and
future crowding
= an important part of preventive orthodontics is the correct handling of space created by premature loss
of deciduous teeth and to know whether this space should be maintained or allowed to close
= as a general rule, whenever the loss of deciduous teeth predisposes the patient to develop malocclusion,
space maintainer should be inserted.
= actually there are no hard rules for determining whether or not the premature loss of deciduous teeth
could result in malocclusion, but there are some guiding principles that must be followed carefully before
making such decision.
= when a deciduous tooth has been lost prematurely, the dentist must ask himself the following question:
1- Has the balance been disturbed?
The question is too difficult and cannot be easily answered, the teeth in the neutral zone are usually in a
state of balance under different forces acting upon them, the teeth themselves are an essential key in
maintaining this balance through their proper contact. When proximal contact is destructed by loss of
tooth, adjacent teeth will have the tendency to migrate into the edentulous space and closing it and thus
the balance disturbed
= this is not particularly true for all cases; some exception exists among which for example:
a- Well-developed dental arches and proper intercuspation; in such cases premature loss of deciduous
teeth not followed by shifting and space closure in most cases

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Dr. Mohammed Alruby
b- State of growth: the loss of the teeth in growing medium may be different from the teeth loss after
growth is completed, the chance of space closure is less in the latter case
c- Generalized spacing of the teeth: in such cases the premature loss of one of maxillary or mandibular
incisors is not followed by shifting or space closure and the construction of space maintainer
become primarily for esthetic reasons
d- The site of lost tooth: premature loss of primary mandibular molars is often requiring space
maintainer because the balance is more likely to be disturbed in this area
= if your decision is not to retain the space, it is important to check it periodically. If there is any
evidence of space closure, space maintainer should immediately inserted
2- Will the structures adapt to the space loss favorable or unfavorable?
One of the interesting properties of human organism is the ability to accommodate itself to environmental
stimuli, actually both favorable and unfavorable adaptation may occur as a results of premature loss, for
example:
a- When one of the primary molars is lost prematurely, lateral tongue thrust may occurs an adaptive
mechanism to close this space.
Actually this has favorable sequelae which is preservation of the space for permanent successors i.e.
The tongue provides some sort of dynamic space maintainers, also has favorable sequelae which is
the development of abnormal tongue habit which might cause open bite at this area.
b- Another example is the mucosa at the extraction site which when irritated by the action of mastication
and the food bolus it will become more fibrous and the underlying bone become more resistant which
considered as a favorable adaptive mechanism, however this may prevent eruption or causes
malposition of permanent tooth which unfavorable sequelae
3- Is the loss of deciduous tooth stimuli abnormal muscle function or habits?
Not all muscles react favorable to the tooth loss, for example, the loss of one of mandibular incisors in
cases of hyperactive mentalis muscles may followed by shifting of the teeth and midline toward the
extraction space, flattening of anterior segment and collapse of the dental arch.
Sometime premature loss may result in an abnormal muscle function as tongue thrust adaptive mechanism,
abnormal chewing habits also lip biting thumb sucking are more likely to develop especially when
premature loss in the anterior segment in such cases space maintainer is indicated.
4- Will the occlusion be sufficient to prevent migration of the teeth?
Proper intercuspation of the teeth may actually prevent migration of the teeth and space closure. This is
particularly true for the 1st
permanent molars when present good intercuspation, but if show cusp to cusp
relationship this will be largely wishful thinking because the intercuspation is poor, this would be applied
to primary teeth because the poorly defined occlusal table.
5- What does the premature loss of deciduous teeth effect the eruption time of its successor?
Premature loss of deciduous tooth may accelerate or identify retard the eruption of its permanent
successors, this depends on the developmental status and the amount of bone covering the permanent tooth
at the time loss of its predecessor. Periapical radiograph is important to evaluate the condition:
a- When more than 1/3 of the root is already formed and there is no thick bulk of covering bone,
accelerate eruption may occur
b- When less than 1/3 of the root is formed and there is thick bulk of covering bone and the gum may
become more fibrous and the eruption may be retarded indefinitely.
Do not surprise when see premolar erupt at 7 years and other in other case erupt at 15 years of
age
6- If the malocclusion is already present, will it has any effect on the space created by premature loss?
The answer depends on the type of malocclusion, as;

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Dr. Mohammed Alruby
a- In class II div 1 with hyperactive mentalis muscle, the loss of one of lower primary molars may result
in collapse of lower dental arch and increase the severity of class II
b- In case of crowding and arch length deficiency, premature loss of deciduous tooth is followed by
rapid space closure
c- In cases of large tongue and generalized spacing, space loss does not frequently occur and space
maintainers would not be necessary
7- If the space maintainer has to be placed, what kind of appliance should be used?
This depend on many factors including:
- Type of the tooth lost
- Type of malocclusion
- Patient cooperation
- Health of remaining teeth
- Age of patient
Factors influencing development of malocclusion following premature loss of deciduous teeth:
a- Abnormalities of oral musculatures, tongue thrust, hyperactive mentalis muscle
b- Presence of oral habits, thumb sucking, finger nail biting
c- Presence of incipient malocclusion; potential class II and class III and poor intercuspation and
arch length inadequacy
d- Sequence of eruption, age of patient, state of occlusal development, premature loss occurs before
or after eruption of 6
Space maintainers
Indications:
As a general rule, whenever the loss of deciduous teeth predisposes the patient to malocclusion, space
maintainer is indicated. Thus indication of space maintainer can be summarized as follows:
1- When disturbance in balance and shifting of the teeth is expected, this actually true for the
premature loss of one of primary mandibular molars
2- When abnormal muscle function is expected following premature loss as: premature loss of
mandibular incisors associated with hyperactive mentalis muscle
3- When premature loss of deciduous teeth can stimulate an abnormal habit as: tongue thrust, thumb
sucking
4- Poor intercuspation and expected shifting
5- Presence of potential malocclusion which might become more sever after premature loss, for
example: arch length inadequacy and expected crowding
6- When the arch length is sufficient to accommodate all permanent teeth anterior to 1st
permanent
molars in a good alignment and no further treatment will require at latter age.
7- When periapical radiographs reveals:
a- Abnormal sequence of eruption, when ectopic eruption is expected
b- Delayed eruption of permanent teeth due to either:
- Less than 1/3 of the root is formed
- Appreciable amount of alveolar bone covering the tooth
c- Uneven resorption of deciduous teeth roots and arch length deficiency is expected
8- When the space supervision reveals sign of closure
9- If retention of space will aid in prevention of further complicated treatment at later age.
Contraindication of space maintainer:
1- When tooth eruption is expected within few weeks as evidenced by:
- Formation of more the 1/3 of the roots
- No or little amount of covering alveolar bone.
2- Generalized spacing and large tongue

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Dr. Mohammed Alruby
3- When space required for permanent teeth is in excess as evidenced by actual analysis of x-ray and
cast
4- When the space retention will be complicated the condition as arch length inadequacy, the space is
allowed to close
5- When the permanent successor is congenitally missing and there is arch length inadequacy
6- Well-developed dental arches and proper intercuspation.
Requirement of space maintainer:
1- Should maintain the mesio-distal as well as the vertical dimension of lost tooth
2- If possible it should be functional at least to prevent over eruption of opposing tooth
3- Should be simple and easily fabricated
4- Should be storage enough to acts over the required periods
5- Should not endanger the remaining teeth or soft tissues
6- Should not interfere the normal growth and function
7- Should be hygienic and easily cleaned
Types of space maintainer:
I- a- functional: maintain the mesio-distal as well as vertical dimension of the teeth, in addition
restore normal functions (mastication and speech) and esthetics
b-non-functional: maintain the mesio-distal width only
II- a- fixed: band or chrome steel crown and loop maintainer, fixed lingual arch cantilever and
space regainers
b-semifixed: cantilever maintainer
c-removable: acrylic partial denture
III- a-active: space regainer
b-passive: band and loop space maintainer.
Factors affecting the type of space maintainers
Selection of space maintainer depends upon the following:
1- the tooth or teeth lost
2- the age of the patient, the sex of the patient
3- the health of the remaining teeth
4- the type of occlusion
5- possible speech involvement
6- patient cooperation
7- performance of the operator.
Space maintainer in maxillary and mandibular anterior segments
In maxillary anterior segment:
= space maintainers are not usually required even with drifting of the teeth because the inter-canine width
will increase by normal growth, however in very young children, space maintainer for this segment is
required to prevent lisping and speech defects as well as for esthetic and psychological reasons. In such
cases, removable partial denture is the appliance of choice if the child is quite cooperative.
In mandibular anterior segment:
= the construction of space maintainer for this area is controversial. You must sure that the musculature,
functional forces, growth and developmental pattern will work together to overcome the effect of tooth loss,
otherwise space maintainer must be inserted because the lower arch is the contained arch and is more
likely to collapse after premature loss. Also as the permanent mandibular incisors erupt they will need
every available bite of space to achieve normal position

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Dr. Mohammed Alruby
Fixed space maintainer as: metal crown with cantilever pontic, canine to canine or molar to molar fixed
lingual arch are the appliance of choice for this segment, removable space maintainer is undesirable in
this region because of:
- poor retention
- possible removal at meal time
- may be lost
- may interfere with normal eruption of permanent mandibular incisors which usually erupt
lingually and then uprighted by action of the tongue (festoons of removable space maintainer
prevent this movement)
space maintainers in the buccal segments:
careful space analysis is required, age, sex of the patient and the time at which premature loss occurs must
take into consideration before taking decision
diagnostic aids:
- full periapical radiograph using, long cone technique
- study casts
- panoramic radiograph
- Moyers mixed dentition analysis chart if possible
Information required:
- Lee way space
- Pattern of deciduous teeth roots resorption
- State of development of permanent teeth
- Sequence of eruption of permanent teeth
- The position of erupting permanent teeth
- Character of alveolar bone
- Type of malocclusion: normal or abnormal
- Growth pattern
- Age of patient
- Sex of patients: teeth of girls erupt 1.5:2 years earlier than boys
- The presence of abnormal muscle function
- The presence of abnormal habits
= all this information is required to know whether or not you must retain the space
= among the common mistakes is the space retention in the deciduous canine region where serial extraction
is indicated.
This depend on the degree of arch length deficiency
= slight deficiency ------- space maintainer
= severe deficiency --------serial extraction
= when the operator decides not to retain the space, a periodic supervision at 2 months’ intervals is
necessary
Space maintainer for the 1st
primary molars area
In the maxillary arch:
Most investigator feel that the loss of 1st
primary molars is less critical than loss of 2nd
primary molars and
is not followed by space closure in most cases for 2 reasons:
- The 1st
premolars erupt before canines.
- The 2nd
premolars seems to resist the unwanted shifting of 1st
permanent molars
In the mandibular arch:
The loss of 1st
primary molars is more critical and often require space maintainer
The effect of premature loss of 1st
primary molar also depends on the stage of development of
Occlusion at the time of loss:
- If loss occurs during the active eruption of 6 a strong mesial force will be exerted on E which
accordingly tip to close the space

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Dr. Mohammed Alruby
- If the loss occurs during active eruption of lateral incisors, the primary canine will drift distally
and close the space
In such cases space maintainer should be placed if another consideration permits or if serial extraction is
not indicated, when you decide to retain the space in this region, the fixed type as band or crown with loop
are the appliance of choice.
Space maintainer for 2nd
primary molars area:
= the 1st
permanent molars will shift mesially closing the space created by premature loss of 2nd
primary
molars, resulting in impaction of 2nd
premolars.
= the degree of mesial shifting of 6 depends upon the time at which the 2nd
primary molar is lost:
- If the second primary molar is lost before eruption of 6 it will erupt far mesially closing the
most of space. Band or chrome steel crown and loop with distal tissue extension may guide 6 to
normal eruption, however in some cases it may interfere with normal eruption of 6
- If 2nd
primary molar is lost after eruption of 6 the 6 may be tipped slightly or excessively
depending on the type of occlusion, intercuspation, muscle factor and he presence of arch length
deficiency and other factors. The condition will be more critical in the lower arch than in upper.
Band or chrome steel crown and loop maintainer are the appliance of choice in this region
Space maintainer for primary canine region:
= this depend on the degree of arch length inadequacy and whether serial extraction is indicated or not
= in sever arch length inadequacy, the extraction of primary canine will be a part of the planned program
of serial extraction and the space of primary canines is utilized for aligning of incisors
= in mild arch length deficiency which can solved by other means rather than extraction or in cases of
arch length sufficiency, the space of prematurely lost primary canine should be retained, otherwise
permanent canine may be blocked labially or lingually
Space maintainer for areas of multiple teeth loss:
Acrylic partial denture or full denture for children, canine to canine, molar to molar rigid lingual arch 0.7
or 0.8 stst wire are available according the case.
Fixed space maintainers
A- Functional space maintainers:
1- Fixed bridge:
= fixed bridge is very rarely used for the following reasons:
- Exert a tolerable load upon abutment teeth
- Require much chair time and much laboratory work and much adjustment
- Require reduction of abutment teeth
= it can be constructed for the anterior region by ¾ crown preparation on abutment teeth with the least
possible reduction.
= full veneer metal crown for posterior segment, an acrylic pontic is constructed and attached to the
abutment by metal bar soldered to the crown
2- Crown and bar or band and bar maintainers:
This is the simplest functional space maintainer, if not the most desirable bar is soldered to the tooth ends
of abutment teeth crown or bands. Crown is preferable than bands because of less caries susceptibility and
less likely to require re-cementation later

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Dr. Mohammed Alruby
3- Stress breaker functional space maintainer:
It is one of the most successful types of functional retainer, it is consisting of two crowns or two bands L
shape stst or nickel chrome and round vertical tube. The L shape bar is soldered on the mesial surface of
the crown of one abutment and other end fit vertical tube soldered on the distal surface of the crown of
other abutment
Band or crown, bar and sleeve retainer allows vertical movement of abutment under-functional forces, so
that, it prevent un-tolerable loads being thrust upon the supporting teeth.
B- Non-functional fixed maintainers:
1- Band and loop or chrome steel crown and loop maintainer
Advantages:
- Easily constructed
- Non expensive
- Provides rooms for erupting permanent teeth
Disadvantages:
Cannot restore the vertical dimension
- Will not restore the masticatory function
- It will not prevent over eruption of opposing teeth
Steps of construction:
- Selection of an orthodontic band or crown to fit the tooth (usually distal to the space)
- A compound impression is taken with band or crown in place
- The band or crown is removed from the tooth and replace securely in the compound impression
- The cast is poured
- A loop of 0.7 stst wire is contoured to rest on the tissue so that its mesial end is contact the
mesial abutment and its distal end is soldered to the mesial surface of distal abutment band or
crown
The loop should be wide enough to permit eruption of permanent tooth
- The maintainer is removed from the models, finished and polished and cemented in the mouth
**** this type can be made directly in the mouth by adapting and contouring the loop directly in the mouth
of the patients, the point of contact between the loop and distal abutment is marked by marking pen. Then
the band is removed and the loop is welded at this point by spot welding. Re-check again in the mouth until
desired position of the loop is obtained.
Then the loop is soldered to the band by silver and flux, finished and cemented in place.
2- Band or crown and loop with distal shoe tissue extension:
This type is indicated when 2nd
primary molar is prematurely lost before eruption of 1st
permanent molar,
the distal tissue extension may help to guide the 1st
permanent molar into normal eruption, on the other
hand it may interfere with its eruption
Steps in construction:
- A band or crown is soldered for the 1st
primary molar
- A compound impression is taken
- The band is removed and replaced in the impression and the stone cast is poured
- If the 2nd
primary molar is planned for extraction but still not, it should be cut off the model.
- A hole is made in the model in the area of disto-buccal root of 2nd
primary molar using drill,

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Dr. Mohammed Alruby
The exact length of the hole should be determined by X-ray measurement of the disto-buccal root
length of 2nd
primary molar
- The loop is made and contoured on the tissues and its mesial end is soldered to the distal surface
of 1st
primary molar band or crown and its distal end is soldered to the gold extension in the
hole
- The appliance is finished and polished, the gold extension is sharpened by carborundum stone
- Try the appliance in the mouth before cementation, X-ray film is essential to see the relation of
the gold tissue extension to the erupting 1st
permanent molar
When good relation is present, the appliance is cemented in place, it was found that the tissue
can tolerate the gold extension very well
3- Passive lingual arch:
It is the space maintainer of choice following the multiple loss of the teeth in maxillary or mandibular arch.
Although it does not restore function or prevent over-eruption of opposing teeth, it has many advantages:
- Eliminate the problem of patient cooperation
- No problem of breakage or loss
- Less caries susceptibility
Steps of construction:
= orthodontic bands are adapted on 1st
permanent molars or the most posterior teeth on the arch on both
sides
= Compound impression is taken with bands in place, the bands are removed and placed in impression
accurately in place
= The stone cast is poured
= 0.8 stst wire is contoured from the band on one side to the band on the other side of the arch and should
touch the cingulum of anterior teeth just above the gingival margin
= the free ends are soldered to the middle of lingual surface of the molars bands on both sides
Vertical loops may incorporate in the wire just mesial to the molar bands if space requiring is indicated
= the appliance is finished and polished then cemented.
4- Gerber space maintainer:
This type may be fabricated directly in the mouth during one relatively short appointment and requires no
lab work.
- Orthodontic band or crown is selected to fit the abutment tooth
- The mesial surface of the band is marked for placement of U- shaped assembly which may be
welded or soldered in place
- The u shaped assembly is fit a u shaped tube which should be adjusted until contact the surface
of mesial abutment. A marking pen is used to mark the proper position, then the U wire is welded
in the U tube in this position, occlusal rest can be added to the U tube selection to minimize the
cantilever effect
- If the appliance is used as space regainer the U wire should not welded in the U tube but instead
of open coil spring is placed between the tube and U wire selection

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Dr. Mohammed Alruby
5- Mayne space maintainer:
= impression is taken with bands on 1st
permanent molars
= the bands are removed and placed accurately in the impression then the cast is poured
= 0.036 inch stst wire is soldered on the buccal surface of molar bands then adapted to the buccal aspect
of the edentulous area, then bent lingually at the distal surface of the 1st
bicuspid and adapted to this
surface
= this wire can be activated to move first bicuspid mesially to regain space for erupting 2nd
bicuspid
This design is introduced by Dr. W R Mayne.
6- Cantilever space maintainer:
= similar to band and loop with distal shoe extension
= it is formed of casted crown with a bar rest on the tissue at edentulous area at the end of which vertical
flat arm is made to inter the tissues just mesial to the erupting 1st
molar
= careful radiographic assessment is required
= the space maintainer should be modified after eruption of 1st
permanent molars
=== the term cantilever refers to any appliance or restoration that have an extended wire that carries a
pontic or modified to perform function
Removable space maintainer
Advantage:
1- Tissue born impose less stress on adjacent teeth.
2- They can be restoring masticatory function, prevent over eruption of opposing teeth, aids in normal
speech, provide accepted esthetics
3- Easily fabricated and non-expensive
4- More hygienic and easily cleaned
5- Stimulate the tissue beneath them and thus accelerate eruption of permanent teeth

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Dr. Mohammed Alruby
Disadvantages:
1- Demand patient cooperation, so it can be lost or broken
Removable space maintainers are indicated in areas of multiple teeth loss or bilateral teeth loss
It is the appliance of choice in the maxillary arch, but the problem of retention in the mandibular arch may
restrict their use, so passive lingual arch in mandible is superior to it
Removable space maintainer can be:
- Removable partial denture
- Full denture for children
Fixed removable space maintainer
= this type may be indicated to overcome the problem of retention in removable partial denture
The use of partial or full crowns with lugs to assist in retention usually increase efficiency of removable
space maintainers
Fixed removable lingual arch
In which the vertical tubes are soldered on the lingual surface of molar bands to which the lingual arch is
fitted. This method permits the dentist to remove and adjust the lingual arch if necessary.

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Dr. Mohammed Alruby