abnormalities of individual tooth positions ,dental arches and basal arches are presented

1. Malocclusion of
teeth
Dr Maher Fouda
Professor of orthodontics
Faculty of Dentistry Mansoura Egypt

2. Normal occlusion
In a normal sagittal occlusion, the mesio-buccal cusp of the
maxillary first molar occludes with the mesio-buccal groove of
the mandibular first molar .The maxillary canine cusp tip
occludes between the mandibular canine and first premolar .

3. In normal occlusion there is alignment
of the teeth, normal overbite and
overjet and coincident maxillary and
mandibular midlines.

4. A malocclusion is a misalignment or
incorrect relation between the teeth of the
two dental arches when they approach
each other as the jaws close

5. While occlusion refers to the proper alignment of
teeth in the upper and lower jaws so that they fit
together to create a healthy "bite," malocclusion
refers to a disruption of this alignment and incorrect
relation between the upper and lower teeth.

6. To understand a group of identities it is advisable to
divide them into groups and subgroups based on
certain similarities. Classification of malocclusion is the
description of dentofacial deviations according to a
common
characteristic, or norm.

7. Various classifications are
proposed by different researchers based on their
experiences and depending upon what they found to
be clinically relevant.

8. The understanding of these
classifications is essential for the student of
orthodontics as they would be frequently referred to
during communications between consultants and
sometimes, certain identities within a subgroup will
require the same treatment protocols.

9. Depending upon which part of the oral and
maxillofacial unit is at fault, malocclusions can be
broadly divided into three types-
• Individual tooth malpositions.
• Malrelation of the dental arches or dentoalveolar
segments.
• Skeletal malrelationships.

10. The alveolar process (also called the alveolar bone) is the thickened
ridge of bone that contains the tooth sockets (dental alveoli) on the
jaw bones that hold teeth. In humans, the tooth-bearing bones are the
maxilla and the mandible.The curved part of each alveolar process on
the jaw is called the alveolar arch
alveolar process

11. The dental arches are the two arches (crescent
arrangements) of teeth, one on each jaw, that
together constitute the dentition
Maxillary dental arch

12. The term “apical base” is used to describe basal bone and
was first defined by Lundstrom in 1925 as the junction of the
alveolar and basal bones of the maxilla and the mandible in
the region of the apices of the teeth.
apical base

13. These three can exist individually in a patient or in
combination involving each other, depending upon
where the fault lies—in the individual dental arch or
the dentoalveolar segments or the underlying skeletal
structure.

14. An erupted or partly erupted tooth may occupy a position other
than normal by being inclined, i.e., the crown of the tooth may
occupy an abnormal position while its apex is normally placed.
INDIVIDUAL TOOTH MALPOSITIONS

15. On the other hand, the crown and the root
of the tooth may be
bodily displaced in the same direction.

16. In addition, a tooth may be
rotated on its long axis. The various
anomalies are designated
according to the direction and nature of
the malposition

18. These are malpositions of individual teeth in respect
to adjacent teeth within the same dental arch. Hence,
they are also called intra-arch malocclusions.
These can be of the following types:
MESIAL INCLINATION OR TIPPING
The tooth is tilted mesially, i.e. the crown is mesial to
the root .
Mesially inclined/tipped central incisors.
The long axis of the teeth is depicted in black and red , with
the midline in white and black dots

19. describes a tooth which is bodily displaced
towards the mid-line of the dental arch.
Mesial bodily displacement

20. DISTAL INCLINATION OR TIPPING
The tooth is tilted distally, i.e. the crown is distal to
the root .
Distally inclined
maxillary right
lateral incisor. The
long axis is depicted
in
black, with the ideal
inclination of the
tooth
depicted by white
dots
Distally inclined maxillary maxillary
central incisors with midline
diastema between them

21. describes a tooth which is bodily displaced
in a direction away from the mid-line of the arch.
Distal displacement

22. Median diastema is a term which
is commonly applied to the
space which results when two
upper central incisors are in distal
inclination or distal displacement.
More simply, the term 'midline
space' may be used.

23. LINGUAL INCLINATION OR TIPPING
The tooth is abnormally tilted towards the tongue (or
the palate in the maxillary arch) .
Palatally inclined maxillary
left incisor
Lingually inclined
mandibular second molars

24. is a term frequently used also
to refer to the lingual tilting of the anterior teeth.
Retroclination

25. LABIAL/BUCCAL INCLINATION OR TIPPING
The tooth is abnormally inclined towards the lips/
cheeks .
Labially inclined maxillary right central incisor

26. proclination
may be used also to describe the outward tilting of inisors and
canine teeth towards the lips condition. In the case of the
molars and premolars, the term 'buccal' inclination is used. The
composite term 'Vestibular' may be used to embrace both 'labial'
and 'buccal' when indicating the outer side of the dental arch.

27. are used similarly to describe
bodily displacement of teeth in an
outward direction.
Labial and buccal displacement

28. describes a tooth bodily displaced towards
the tongue.
Lingual displacement

29. INFRA-OCCLUSION
The tooth is below the occlusal
plane as compared to
other teeth in the arch.
Right mandibular Ist premolar in infra-
occlusion

30. SUPRAOCCLUSION
The tooth is above the occlusal plane as
compared to
other teeth in the arch .
Supraerupted maxillary anteriors Maxillary central and mandibular
incisors are supraerupted

31. ROTATIONS
This term refers to tooth movements around the long
axis of the tooth. Rotations are of the following two
types:
Mesiolingual or Distolabial
The mesial aspect of the tooth is inclined lingually or
in other words, the distal aspect of the crown is labially
placed as compared to its mesial aspect .
Maxillary central incisors are rotated
mesio-palatally

32. Distolingual or Mesiolabial
The distal aspect of the tooth is inclined lingually or
in other words, the mesial aspect of the crown is
labially placed as compared to its distal aspect .
Maxillary left central incisor is rotated mesio-buccally

33. Transposition
This term is used in case where two teeth exchange
places, e.g. a canine in place of the lateral incisor .
Transposition of the mandibular right canine with
the mandibular right lateral incisor

34. canine changed its position with the FIRST BICUSPID
Transposition

35. An overlap of incisors and canines due to crowding.
The overlapping of incisor teeth in the same direction
imbrication
OR
describes teeth (especially lower incisors) which
are irregularly arranged within the arch due to lack of space for
them
OR

36. The most common orthodontic problem is crowding. By
definition, crowding occurs when the width of the teeth, in
either the upper or lower jaw, is greater than the amount of
space available. Crowding takes many different shapes and
forms and no two instances will be the same.
OR Crowding, or tooth size arch length deficiency, is
one of the most common reasons that people seek
orthodontic treatment for themselves or their children

37. Crowding results in maligned or crooked teeth and
may result in rotated teeth, overlapping teeth,
and/or in and out discrepancies between adjacent
teeth. Crowding may also preclude teeth from
erupting into the arch form and may result in
impacted teeth (teeth stuck in the bone).

38. Spacing, the opposite of crowding, is an excess of space for your
teeth, resulting in gaps between your teeth. This generally occurs
when the teeth are smaller than the available space. Spacing can
also be caused by protrusive teeth, missing or impacted teeth, or
abnormal tissue attachments to the gums.

39. Spacing should be corrected because it can:
•Result in gum problems due to the lack of protection by the teeth.
•Prevent proper functioning of the teeth.
•Make your smile less attractive

40. MALRELATION OF DENTAL ARCHES
These malocclusions are characterized by an abnormal
relationship between teeth or groups of teeth of one
dental arch to that of the other arch. These inter-arch
malrelations can occur in all the three planes of space,
namely—sagittal, vertical or transverse.

41. In the sagittal classification, the basis for assessment is the
intermaxillary positions of the first molars.There exist three
characteristics: normal, postnormal (Angle Class II) and prenormal
(Angle Class III) occlusion.
normal postnormal (Angle Class II) prenormal (Angle Class III) occlusion.

42. SAGITTAL PLANE MALOCCLUSIONS
They can be of two types:
Pre-normal Occlusion
Where the mandibular dental arch is placed more
anteriorly when the teeth meet in centric occlusion
Angle Class III malocclusion (prenormal occlusion).Angle Class I occlusion (normal occlusion).

43. Angle Class III, or prenormal, occlusion is evident when
the mandibular first molar is in a prenormal position
compared to the normal occlusion, i.e. in front of the
normal position, or in a mesial relationship . In cases of
Angle Class III occlusion, the overjet is often reversed
(<0 mm), implying an anterior crossbite
Angle Class III malocclusion (prenormal occlusion).
The mandible is placed more anteriorly as
compared to normal

44. Post-normal Occlusion
Where the mandibular dental arch is placed more
posteriorly when the teeth meet in centric occlusion.
The mandibular arch is located more
posteriorly as compared to normal
Angle Class II malocclusion (postnormal occlusion).

45. In an Angle Class II, or postnormal, occlusion, the mandibular
first molar has a posterior position compared with normal
occlusion, i.e. behind the normal position or in a distal
relationship .
Angle Class II malocclusion (postnormal occlusion).

46. In about 90% of the Angle Class II occlusions, the
maxillary incisors are proclined, i.e. Angle Class II
division 1 , while approximately 10% show
retroclined maxillary central incisors, i.e. Angle Class
II division 2 .
Angle Class II division 1 malocclusion (a) with proclined maxillary incisors (red line in
a), and Angle Class II division 2 malocclusion (b) with retroclined maxillary central
incisors (purple line in b).

47. In an Angle Class II division 1 occlusion, the overjet is
often enlarged, and if the overjet is over 6 mm, it is
counted as great, and anything above 9 mm is
considered extreme

48. Overjet’ is a horizontal measurement referring to the
distance between the lingual aspect of the maxillary
incisors and the labial surface of the mandibular
incisors when the teeth are in habitual or centric
occlusion.

49. Bimaxillary Protrusion
Occasionally, the mesiodistal relationship of the upper
and lower first molars may be normal and the
interdigitation of the buccal segments correct, with no
overt tooth malpositions, but the entire dentition is
forward with respect to the facial profile. The
orthodontist calls this a bimaxillary protrusion .

50. on their respective bases. Bimaxillary
protrusions usually fall in the Class I
category
With normal anteroposterior jaw
relationship, the teeth are forward

51. They can be of two types depending on the vertical
overlap of the teeth between the two jaws.
VERTICAL PLANE MALOCCLUSIONS
The term ‘overbite’ applies to the distance that the
maxillary incisal margin closes vertically past the
mandibular incisal margin when the teeth are brought into
habitual or centric occlusion.

52. Deep Bite OR ‘closed bite’
Here the vertical overlap between the maxillary and
mandibular teeth is in excess of the normal .
Anterior deep bite

53. Deep bite is defined as an excessive vertical overlap of the incisors,
i.e. vertically, where more than two-thirds of the buccal surfaces of
the mandibular incisors are covered by the maxillary incisors . Most
often, the reason for deep bite is an over-eruption of the incisors or
an anterior rotation of the mandible.
A deep bite with contact between the edges of the mandibular incisors and the
palatal mucosa behind the maxillary incisors

54. A deep bite occasionally manifests with contact
between the edges of the mandibular incisors and the
palatal mucosa behind the maxillary incisors . In such
cases, the contact between incisors and the mucosa
may cause tissue ulceration. Therefore, the
classification of deep bite includes evaluating whether
contact exists between incisors and palatal mucosa
and whether ulcerations occur.

55. Open Bite
Here there is no overlap or a gap exists between the
maxillary and mandibular teeth when the patient bites
in centric occlusion. An open bite can exist in the
anterior or the posterior region.
Anterior open bite
Posterior open bite due
to the presence of a
lateral tongue thrust
habit

56. TRANSVERSE PLANE MALOCCLUSIONS
These include the various types of cross bites.
Generally the maxillary teeth are placed labial/buccal
to the mandibular teeth. But sometimes due to the
constriction of the dental arches or some other reason
this relationship is disturbed, i.e. one or more maxillary
teeth are placed palatal/lingual to the mandibular
teeth . These differ in intensity,
position and the number of teeth that may be involved.
The posterior segment is in cross bite Single maxillary lateral incisor in cross bite

57. In a posterior crossbite, the buccal cusps of the maxillary premolars
and/or molars occlude lingually to the buccal cusps of the mandibular
premolars and/or molars.The posterior crossbite can be either
unilateral or bilateral. Unilateral crossbites of dento-alveolar origin are
caused by palatal tipping of the maxillary premolars and molars, and is
most often accompanied with a forced guidance of the mandible, thus
deviating the midline of the mandible to the crossbite side .
Unilateral crossbite on the right side of the individual, and there has been a forced
guidance of the mandible, deviating the midline to the crossbite side (arrow).

58. A bilateral crossbite is often caused by a transversal
skeletal constriction of the maxilla and without a forced
guidance of the mandible.
Bilateral crossbite.

59. Scissors bite
In a scissors bite situation, one or more premolars or molars in
the maxilla occlude with their lingual cusps buccal to the
mandibular buccal cusps of the premolars and/or molars .
Scissors bite may occur unilaterally or bilaterally and be
associated with forced guidance of the mandible, but forced
guidance is more infrequent than in posterior crossbites.
Bilateral scissors bite is occasionally referred to as the Brodi
syndrome.

60. Angle classified occlusion according to the molar relationship and this remains the most internationally
recognized classification of malocclusion.When looking at ideal occlusion, Angle found that the
mesiobuccal cusp of the upper first permanent molar should occlude with the sulcus between the mesial
and distal buccal cusps of the lower first permanent molar .
Introduced by Edward H. Angle in1899.
Angle’s Classification

61. • Class I—the position of the dental arches is normal,
with first molars in normal occlusion.
• Class II—the relations of the dental arches are
abnormal, with all the mandibular teeth occluding
distal to normal. Angle recognized two subdivisions
under class II:
• Class II division 1—upper incisors are protruding;
• Class II division 2—upper incisors are lingually
inclined.
• Class III—the relations of the dental arches are also
abnormal, with all mandibular teeth occluding mesial
to normal.
He therefore based his classification of occlusion
on this relative mesiodistal position:

62. Class I Malocclusion
A normal molar relationship exists but there is
crowding, misalignment of the teeth, cross bites, etc.

63. A malocclusion where the molar relationship shows
the buccal groove of the mandibular first molar
distally positioned when in occlusion with the
mesiobuccal cusp of the maxillary first molar.
Class II Malocclusion

64. Class II Malocclusion has two divisions to
describe the position of the anterior teeth.
Class II Division 1 is when the maxillary
anterior teeth are proclined and a large overjet
is present.
Class II Division 2 is where the maxillary
anterior teeth are retroclined and a deep
overbite exists.
Class II Malocclusion
Class II Division 1
Class II Division 2

65. •First permanent molars are not fixed points
•Based only on anteroposterior relationship
•Skeletal and dental malocclusion – not
differentiated
•Individual tooth malpositions cannot be
visualised
•Cannot apply in cases of missing first molars
Limitations of Angle’s Classification

66. Skeletal classification takes into account the classification of the
facial skeletal pattern and its relationship with the teeth. There
are three classes under skeletal classification as well.
Skeletal Classification

67. Thus Skeletal I can be taken to indicate a dental base relation
which is favourable to the production of a satisfactory occlusion
either by normal development or by orthodontic tooth movement.
Straight Profile
Class 1: The bones of the face and the jaw are in harmony with one
another and with the rest of the head. The maxilla is slightly ahead of
the mandible. The profile is orthognathic .

68. Skeletal 2
Convex Profile
OR Class 2: Subnormal distal mandibular development in relation to the
maxilla. Maxillary dental arch is narrower than mandibular and there is
crowding in the canine region, crossbite and reduced vertical height. Protrusion
of the maxillary anterior teeth. The profile is retrognathic .

69. Skeletal 3
Concave Profile
OR Class 3: Overgrowth of the mandible and obtuse
mandibular angle. The profile is prognathic at the mandible.

70. SKELETAL MALOCCLUSIONS
These malocclusions are caused due to the defect in
the underlying skeletal structure itself. The defect can
be in size, position or relationship between the jaw bones.

71. Skeletal Class II malocclusion, either division 1 or 2,
is characterized by a mandibular retrusion, a
maxillary protrusion, or a combination of both.
Skeletal Class II division 2Skeletal Class II division 1

72. Skeletal Class II, Division 1 Malocclusion
The maxilla was normal relative to the cranial base
with an SNA at 80°. The mandible was retrognathic
with an SNB value of 73°. The maxillary incisors
were proclined.

73. CEPHALOMETRIC X-RAY

74. The skeletal Class III is the malocclusion the most
studied genetically. Class III malocclusion is caused
by a deficiency of the maxilla growth, excessive
mandibular growth, or a combination of both
Class III du to
maxillary retrusion
and mandibular
protrusion

75. Skeletally, the patient had a prognathic
mandible and a hypoplastic maxilla, a severe
Class III sagittal relationship,
Skeletal Class III

76. SNA
SN-Npog
S N
A

77. Dental Class II Division 2
Malocclusion and class 2 skeleton
Dental Class II Division 2 Malocclusion and class 2 skeleton

78. Cephalometric analysis showed Class II skeletal
pattern with ANB angle 4 degrees, horizontally
directed growth, retrusive mandible and skeletal deep
bite.
Cephalometric x-ray
ANB angle

79. Transversal Skeletal Malocclusion
transverse maxillary deficiency,
MARPE appliance in which miniscrews are incorporated to the screw
support design, with measures determined on the basis of
morphology of the palatal region parallel to the midpalatal suture: A)
MSE expansion appliance (maxillary skeletal expander, B) MARPE
appliance modified by Suzuki et al

80. Vertical Skeletal Malocclusion
Vertical skeletal malocclusions can be classified
as skeletal open- or deep-bite, both presenting
specific clinical characteristics.
skeletal open-bite skeletal deep-bite

81. Skeletal open-bite is often associated with a negative
overbite, hyper-divergence of the mandibular and palatal
planes, increased anterior facial height, augmented
clockwise facial growth, and proclined incisors.
Skeletal open-bite mandibular planes
palatal planes

82. The inverse features, such as an increased vertical overlap between the
upper and lower incisors, short anterior lower face height, excessive
forward rotation of the mandible, horizontal palatal plane and a large
gonial angle characterize the skeletal deep-bite individuals
Class II division 2 with deep over bite
Cephalometric x-ray and cephalometric tracing
horizontal palatal plane
a large gonial angle

83. The presence of open- or deep-bite in patients skeletal
Class II and Class III are to some extent common.
skeletal Class II division 1 with deep over bite
skeletal Class III with deep reverse over bite

84. Reference: