4. The relation of the
Maxillary and Mandibular
teeth when the jaws are
- Closed in centric
relation
- Without strain of
musculature or
displacement of
condyles in their
fossae
OCCLUSION
Definition
5. Ideal & Normal occlusion
“Normal” implies to the variations
around an average mean value
اإلطباق"المثالي"افتراضي مفهوم
“IDEAL” is a hypothetical concept or
a standardized goal
The best arrangement and relationship of
teeth in both the maxilla and mandible
The Perfect Occlusion
6. Ideal occlusion Normal occlusion
- A coincident mid-line - Is one which shows:
some deviation from that of the ideal
but is aesthetically acceptable and
functionally stable for the individual
- the upper and lower teeth fit nicely
and evenly together with the least
amount of destructive interferences
Any deviation from ideal (normal)
that may be considered aesthetically
or functionally unsatisfactory is called
Malocclusion
- No (crowding/spacing/rotations)
Over-jet = 2-4mm
- Correct crown angulation and inclination
- Class I molar & canine relationship
A flat or slightly upwards curve of Spee
maximum contact
Maxillary teeth
slightly overlap
Mandibular teeth
7.
8. Class I molar relationship Correct crown angulation
Correct crown inclination No rotation
No spaces Flat to slight curve of spee
Andrews 6 keys of Normal Occlusion(1972)
9. •The maxillary teeth OVERLAP the mandibular ones
CENTRIC OCCLUSION
•The mesial surfaces of the upper & lower
central incisors are in one line at the median
plane
10. 1) Each tooth in the dental arch occludes with 2 antagonist teeth
in the opposing arch except 2 teeth ??
GENERAL CHARACTERISTIC SIGNS OBSERVED IN THE INTERCUSPAL RELATION
BETWEEN THE 2 ARHES IN NORMAL CENTRIC OCCLUSION
Importance of such design:
a- Stabilizing teeth in position & prevention of tooth elongation
in case of loss of opposite one
b- better distribution of forces
11. 2) Each maxillary tooth is in a more distal position to its antagonist in the
mandibular arch (this is reflected in the molar relationship)
12. Overbite is a vertical measurement
Overjet is a horizontal measurement
3) Overlap relationship
a- Overbite (vertival overlap)
b- Overjet (horizontal overlap)
13. -The Incisal Ridges of the mandibular anterior teeth CONTACT the lingual surfaces of
the maxillary ones
4) Intercuspal relationship:
14. Maxillary teeth
The buccal cusps OVERLAP the buccal cusps of mandibular
Lingual Cusps OCCLUDE with the fossae & central grooves
on the occlusal surfaces of their lower
Mandibular teeth
The buccal
cusps
occlude with the opposing
central grooves & fossae on the
occlusal surfaces of their upper
antagonists
lingual cusps situated in a lingual position to
the upper lingual cusps
17. tooth‐ to‐ tooth contact which prevents or hampers smooth mandibular movement
• Wear of the functional surfaces of
the teeth which is out of proportion
to the patients age.
Interferences: الذي اإلطباقالسفلي الفك حركة سالسة يعوق أو يمنع
The occlusal abnormality may result into:
• Drifting of anterior teeth, loose teeth(mobility).
biomechanical induced dental disease:
• Sensitivity, fracture of tooth
or root, chipping, cracks
• Gingival recession‐ exposed
root surfaces, abfraction ( stress
induced lesions at the
cervicoenamel junction)
18. or incorrect relation between the teeth of the two dental
arches. The term was coined by Edward Angle, the
"father of modern orthodontics", as a derivative of
occlusion, which refers to the manner in which opposing
teeth meet.
Malocclusion is a misalignment of teeth
19. Definition:
Malocclusion may be defined as
―A condition where there is
departure from the normal relation
of the teeth to
- other teeth in the same dental arch
and/or to
- teeth in the opposing arch‖
Malocclusion
المألوف عن الخروج
اإلطباق سوء
20. ii. The buccal cusps and incisal
edges of the mandibular teeth
the line of occlusion passes through
i. The central fossae and along the
cingulae of the maxillary teeth
In Normal Occlusion,
21. 1. (intra-arch problems)
Malpositions of individual or group of teeth in the same arch
2. (inter-arch problems)
3. Malrelation b/w upper & lower dental arches
Malocclusion can be classified depending upon the problems present:
Classification based on intra-arch and intra-arch problems
22. 1. Malpositions of individual or
group of teeth in the same arch
i. Sagittal problems
- Labioversion - Linguoversion
- Mesioversion - Distoversion
ii. Transverse problems
- Crowding - Spacing
- Linguoversion - Buccoversion
iii. Vertical problems
- Supraversion - Infraversion
iv. Rotated teeth
v. Transposition of teeth
2. Malrelation b/w upper & lower
dental arches
Sagittal
• Class II malocclusion
• Class III malocclusion
ii. Transverse
• Crossbites, scissor bite
• Midline shift
iii. Vertical
• Deep bite
• Open bite
Classification based on intra-arch and inter-arch problems
23. is identified by adding the suffix ―version to the direction of
deviation, as follows:
Malposition of individual teeth:
الحقة
The direction of the deviation of a tooth from the line of normal occlusion
Mesioversion Mesial to the normal position
Distoversion Distal to the normal position
Labioversion Towards the lip—Maxillary and Mandibular
anterior teeth.
Buccoversion Towards the cheeks – Maxillary and
Mandibular posterior teeth
Palatoversion Towards the Palate – Maxillary teeth
Linguoversion Towards the tongue—Mandibular teeth
Supraversion Erupted past the line of occlusion—
Overerupted
Infraversion: Short of the line of occlusion—Submerged
Torsiversion Rotated on its long axis
27. Supraversion
• Over-erupted beyond the level of occlusion
• Depressed below the line of occlusion, for
example, primary tooth that is submerged
or ankylosed
Infraversion
28. What else do you see in this photograph?
• Turned or rotated
Torsiversion
30. Malrelation of the upper and lower dental arch is
analyzed in the three planes of space:
Transverse
Vertical
Antero-posterior/sagittal
31.
32. - Abnormal overjet
- Anterior cross-bite
Anteriorly
Posteriorly
Class II malocclusion
Class III malocclusion
In the Sagittal direction
OR
Either :
33. Overjet
It is the h o r i z o n t a l d i s t a n c e between the labial aspect
of the lower incisors and the incisal edge of the upper incisors when
the teeth are in centric occlusion. It is normally 1 to 3 mm.
34. i. Increased overjet: Overjet is more than 3 mm.
ii. Edge to Edge bite: No overjet.
iii. Reversed overjet/ anterior cross bite: Overjet
is negative
Abnormal overjet may be:
35. Anterior Crossbite
It’s the situation when
upper teeth are behind
lower teeth.
Normally, upper teeth
should be in front of lower
teeth.
the primary or permanent maxillary incisors
locked lingual to mandibular incisors
Malocclusion in which the mandibular teeth are in buccal version to the maxillary teeth
36. Pre-normal Occlusion
Class II malocclusion
Class III malocclusion
Postnormal Occlusion
Class I malocclusion
Normal Occlusion
Class III molar and
Class III canine
relationships
Class I molar and
Class I canine
relationships
Class II molar and
Class II canine
relationships
Posterior Sagittal inter-arch problems:
37. Deviations of the midline:
Posterior Cross bite:
In the Transverse direction
inter-arch problems
Either :
Anteriorly
Posteriorly
OR
38. This may be due to: deviation of the upper
midline, lower midline or both
- The midline may be deviated to the right
or to the left
Deviations of the midline:
The upper and lower midlines may be:
- Coincident: normal
- Incoincident:
متطابق
متطابق غير
39. one or more Posterior Teeth occlude in an abnormal buccolingual relation with their
antagonist
Posterior Cross bite:
40. In a posterior cross bite the buccal cusps of the
maxillary posterior teeth usually occlude in the
central fossae of the mandibular teeth.
Posterior Cross bite: It is either unilateral or bilateral:
ii. Bilateral Crossbite:
The etiology is usually
skeletal—A narrow
maxilla and a wide
mandible.
i. Unilateral Crossbite: The etiology is usually abnormal soft
tissue behavior, and sometimes a slight skeletal discrepancy.
42. Definition:
overbite defined as “the overlapping of the upper anterior teeth
over the lowers in the vertical plane”.
“the amount and percentage of overlap of the lower incisors by
the upper incisors” .
5-25% normal (yellow),
25-40% increased (orange)
>40% excessive (red)
Ranges of overbite.
Overbite
ideal overbite ranges from 5-25% overlap.
45. i. Deep overbite: if the overbite is excessive
This abnormality may be due to:
Supraposition of the anterior teeth
Infraposition of the buccal segments
46. ii. Open bite: if the overbite is negative, it is called open bite
This term is applied when there is no vertical overlap of the upper and lower incisors
47. This abnormality may be due to:
Infrapositon of anterior teeth
Supraposition of posterior teeth
Open bite is associated by:
- abnormal soft tissue behavior patterns preventing the
dentoalveolar structures from closing the intermaxillary
space, e.g. thumb, lip and/or tongue.
48.
49. Malrelation is analyzed in three
planes, similar to malrelation of the
dental arches:
I. Anteroposterior
II. Vertical
III. Transverse
Malrelation of the upper and lower apical bases is due to:
a. Abnormal size;
b. Abnormal shape;
c. Abnormal relation to the skull;
d. Abnormal relation to each other.
Malrelation of the apical bases:
50. Assessment of the malrelation of the apical bases in the transverse plane is
done through the analyses of Postero-anterior Cephalometirc X-ray films
Assessment of the malrelation of the apical bases in the anteroposterior and
vertical planes is done through the analysis of Lateral Cephalometric X-rays films
51. Let’s take a look at how orthodontists
classify malocclusions:
To understand what’s involved in orthodontic treatment
52. Why we need a Classification for malocclusion?
In order to:
- acquire a better understanding of the many
deviations from normal occlusion and to
- assist in diagnosis and treatment planning, it
becomes necessary to group the varieties of
malocclusion into order
53. Classification of Malocclusion
Orthodontics made its first appearance more
than a hundred years ago
ANGLE SYSTEM AND ITS MODIFICATIONS
SIMONS SYSTEM
AETIOLOGICAL CLASSIFICATION
BAUME CLASSIFICATION OF PRIMARY TEETH
ACKERMANN AND PROFITT CLASSIFICATION
BALLARDS CLASSIFICATION
WHO CLASSIFICATION
VARIOUS SYSTEMS OF CLASSIFICATION
54. PIONEERED
a system of categorizing
dental irregularities.
Provided the first clear definition of the
normal occlusion
Dr. Edward Angle
He related it to the arrangement of the occlusal
contact of the first permanent molars
ANGLE SYSTEM AND ITS MODIFICATIONS
55. - the mesiobuccal cusp of the maxillary first molar and
- the buccal groove of the mandibular first molar!!!!!!
Angle Classification
• If this molar relationship exists then the teeth can align
into normal occlusion
• In 1890 Edward H. Angle published the
first classification of malocclusion
based on the relationship of:
• The classifications are
56. Angle’s Classification of malocclusion
Class I Class II Class III
Division 1
and
Subdivision
Division 2
and
Subdivision
Class III Pseudo
Class III
Sub-
division
Skeletal
Class III
Angle describes three classes of malocclusion
57. The mesio-buccal cusp of the upper first permanent molar occludes in the buccal groove of
the lower first permanent molar -ــــــــــــــــــ Class I
The mesio-buccal cusp of the upper first permanent molar occludes anterior to the
buccal groove of the lower first permanent molar ــــــــــــــــــ Class II
The mesio-buccal cusp of the upper first permanent molar occludes posterior to
the buccal groove of the lower first permanent molar ــــــــــــــــــ Class III
58. Angle Class І malocclusion:
Line of occlusion: ALTERED in the max. & mand. Arches:
• individual tooth irregularities (crowding/spacing/….etc)
• Inter-arch problems (deep bite/open bite/ increased overjet/…..etc)
Neutroclusion
Molar relationship :
The mesio-buccal cusp of the upper first permanent molar occludes
in the buccal groove of the lower first permanent molar
Canine relationship:
- the mesial incline of upper canine occludes
with the distal incline of lower canine
- the distal incline of upper canine occludes
with the mesial incline of lower first
premolar
59. Problems associated with Class I malocclusion
• Crowding
• Spacing
• Deep Bite
• Open Bite
• Cross Bite
• Localized Teeth Problems
(impaction)
60.
61.
62. Molar relationship:
The mesio-buccal cusp of the upper first permanent molar
occludes anterior to the buccal groove of the lower first
permanent molar ــــــــــــــــــ Class II
Angle Class ІІ malocclusion: Distoclusion
There are two divisions of class ІІ designated, division 1 and division 2:
Class II canine relationship:
- the distal incline of upper canine anterior to
the mesial incline of lower first premolar
63. Angle Class ІІ malocclusion:
Class ІІ Division 1:
- Mandible is retruded and
- all maxillary incisors are protruded
1. V- shaped or constricted maxilla
2. Proclined maxillary incisors
3. Lip trap
4. Exaggerated curve of Spee
5. Deep bite
Line of occlusion: altered in the max. & mand. Arches:
Class II canine & molar relationship
64. Normal occlusal relation on one side of the
arch and class ІІ occlusion on the other side.
Class ІІ malocclusion:
class ІІ molar
class I molar
Subdivision:
65. This is usually characterized by:
(1) Lingual inclination of the maxillary central incisors and may be overlapped by the
maxillary lateral incisors.
(2) Broad maxillary arch
(3) Deep overbite with the maxillary and mandibular incisors in apparent
supraocclusion
(4) Normal length upper lip contacting the lower lip but deep mental groove may be
present.
(5) The mandible is frequently of good size.
Angle Class ІІ malocclusion:
Class ІІ Division 2:
Mandible is retruded and
one or more maxillary incisors are retruded
Class II canine & molar relationship
66.
67.
68.
69.
70.
71.
72.
73. Class II division 1 Class II division 2
1) The upper incisors teeth are proclined 1) The upper incisors teeth showed
lingual inclination and may be overlaped
by the upper lateral incisors teeth
2) Excessive overjet & deep overbite 2) Deep overbite
3) V-shaped upper arch, narrow in the canine
region and broad between the molars
3) The upper arch usually broad
4) Short upper lip with failure in the anterior lip
seal
4) Normal upper lip and lip seal, with
deep mental groove
5) The mandible may be deficient and chin
under developed
5) The mandible is of good size
74. The mesio-buccal cusp of the upper first permanent molar occludes posterior to
the buccal groove of the lower first permanent molar ــــــــــــــــــ Class III
MesioclusionAngle Class ІІІ malocclusion:
Molar relationship:
75. Angle Class ІІІ malocclusion:
This prenormal occlusion may result from :
-excessively large mandible,
-lack of forward growth of the maxilla, or
- a combination of both.
Class ІІІ malocclusion: 2 types
- True class ІІІ malocclusion (Skeletal)
- Pseudo class ІІІ (FALSE or postural)
76.
77. This is not a true class ІІІ malocclusion but its presentation is similar
Here the mandible shifts anteriorly during final stages of closure (acquiring a bite
of accommodation) due to premature contact of the incisors or the canines.
Angle Class ІІІ subdivision:
Where normal occlusal relation
exists on one side and class ІІІ
relation on the other side.
Pseudo class ІІІ (false or postural):
78.
79.
80.
81.
82. Merits/Advantages
1. Angle’s system of Classification is the most
traditional and oldest system still in use
2. Most practical and easy to comprehend method of
Classification
3. Most POPULAR
4. Easy to Communicate
5. Widely used for teaching purpose
Merits/Demerits of Angle’s Classification
مزايا
فهم
83. 1. Disregarded the relationship of the teeth to
the face
2. Malocclusion is a three-dimensional problem,
but Angle considered only sagittal dimension
3. NOT APPLICABLE when first molars are missing
4. Differentiation between dento-alveolar and
skeletal malocclusion is not possible
Demerits/Disadvantages
تجاهل
عيوب
85. ANGLE SYSTEM AND ITS MODIFICATIONS
SIMON’S SYSTEM
AETIOLOGICAL CLASSIFICATION
BAUME CLASSIFICATION OF PRIMARY TEETH
ACKERMANN AND PROFITT CLASSIFICATION
BALLARDS CLASSIFICATION
WHO CLASSIFICATION
VARIOUS SYSTEMS OF CLASSIFICATION
87. FRANKFORT HORIZONTAL PLANE
This plane help to detect devotions in the VERTICAL DIRECTION
Formed by:
drawing a straight line through the bony
margins of the orbit to external
Auditory meatus
Attraction: when the dental arch or part of it is closed to the FHP
Abstraction: when the dental arch or part of it is away from FHP
88. ORBITAL PLANES
This plane used to describe malocclusion in anterio-posterior direction
• Perpendicular to the FHP
• Simon’s law of canine- “this
plane should pass through
the distal third of the canine”
Protraction: when the dental arch or part of it is away from this plane
Retraction: when the arch or part of it is closed or more posteriorly placed
Teeth too anterior to the orbital plane
Teeth too posterior to the orbital plane
89. MID SAGITTAL PLANE
It classifies malocclusion according to Transverse deviation from MSP
Contraction: A part or all of the dental arch is contracted towards MSP
Distraction: A part or all of the dental arch is wider or placed at a
distance which is normal
THIS plane passes at right angle to FHP
90. Advantages
1. 3 dimensional – more precise
2. Lays emphasis on the orientation of dental arch to the facial skeleton
Disadvantages
It is time consuming and cumbersome
مرهق / ثقيل
التركيز يضع
96. Incisor classification
‘the lower incisor edges occlude with or lie
immediately below the cingulum plateau of
the upper incisor’
British Standard incisor
classification
Class I incisor Class II incisor Class III incisor
Definition
97. Incisor classification British Standard incisor
classification
Class II incisor
Definition
The lower incisor edges occlude
posterior
To the cingulum plateau of the
upper incisor
98. Incisor classification British Standard incisor
classification
Class III incisor
Definition
The lower incisor edges occlude
anterior
To the cingulum plateau of the
upper incisor
99. • Addresses the limitations of the Angle’s Classification
• Step–by–step systematic approach to ensure nothing is overlooked
• COMPREHENSIVE
Ackerman-Proffit system of classification
A distinction is made b/w skeletal & dental malocclusions
100. AlignmentProfile
Transverse relationship
Alignment: a dental arch is classified as ideal/crowded/spaced
Profile: convex/ straight /concave
Transverse relationship: Bucco-lingual relationship of posterior teeth
Class
Class: Class I/ Class II/ Class III
Overbite
Overbite: deep bite/open bite (posterior/anterior)