Slide 1: www.rxdentistry.blogspot.com MALOCCLUSION DEFINITION : www.rxdentistry.blogspot.com DEFINITION The deviation from the accepted normal occlusion is malocclusion.
Malocclusion is a condition that reflects an expression of normal biologic variability in the way the maxillary & the mandibular teeth occlude. (BISHARA) Slide 3: www.rxdentistry.blogspot.com An occlusion in which there is a malrelationship between the arches in any of the planes of the space or in which there are anomalies in tooth position beyond the limit of the normal (WALTHER & HOUSTON) CLASSIFICATION : www.rxdentistry.blogspot.com CLASSIFICATION Depending upon which part of the oral & maxillofacial unit is at fault :
Individual tooth malpositions (DENTAL DYSPLASIA)
2. Malrelations of the dental arches or dento alveolar segments. (SKELETODENTAL DYSPLASIA)
3. Skeletal malrelationship (SKELETAL DYSPLASIA) 1) INDIVIDUAL TOOTH MALPOSITION : www.rxdentistry.blogspot.com 1) INDIVIDUAL TOOTH MALPOSITION These are malocclusions of individual teeth in relation to adjacent teeth with in same dental arch.
They also called intra arch malocclusions.
Also includes condition like spacing or crowding with in dental arches.
They are of following - Slide 6: www.rxdentistry.blogspot.com 1. MESIAL INCLINATION OR TIPPING 2. DISTAL INCLINATION OR TIPPING 3. LINGUAL INCLINATION OR TIPPING Slide 7: www.rxdentistry.blogspot.com 4.LABIAL/BUCCAL INCLINATION OR TIPPING
6.SUPRAOCCLUSION Slide 8: www.rxdentistry.blogspot.com 7.ROTATIONS :-
a.Mesiolingual or distolabial
b.Distolingual or mesiolabial
8.TRANSPOSITION 2) MALRELATION OF DENTAL ARCHES : www.rxdentistry.blogspot.com 2) MALRELATION OF DENTAL ARCHES These characterized by an abnormal relationship between teeth or groups of teeth of one dental arch to another arch.
These occur in all the three planes of space, namely –
transverse plane SAGITTAL PLANE MALOCCLUSION : www.rxdentistry.blogspot.com SAGITTAL PLANE MALOCCLUSION A. Pre normal occlusion
Where the mandibular
dental arch is placed
more posteriorly when
the teeth meet in
centric occlusion. Slide 11: www.rxdentistry.blogspot.com b. Post normal occlusion
Where the mandibular dental arch is place more distally when the teeth meet in centric occlusion. VERTICAL PLANE MALOCCLUSION : www.rxdentistry.blogspot.com VERTICAL PLANE MALOCCLUSION A. Deep bite or increase over bite
B. Open bite TRANSVERS PLANE MALOCCLUSION : www.rxdentistry.blogspot.com TRANSVERS PLANE MALOCCLUSION These includes various types of cross bites due to constriction of the dental arches or some other reason the relationship is disturbed. 3) SKELETAL MALOCCLUSIONS : www.rxdentistry.blogspot.com 3) 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 b/w the jaw bones. VARIOUS SYSTEM OF MALOCCLUSION : www.rxdentistry.blogspot.com VARIOUS SYSTEM OF MALOCCLUSION Angle’s classification.
Ackerman-Proffit system ANGLE’S CLASSIFICATION OF MALOCCLUSION : www.rxdentistry.blogspot.com ANGLE’S CLASSIFICATION OF MALOCCLUSION In 1899 EDWARD H. ANGLE classified malocclusion based on the mesio-distal relation of the teeth,dental arches & jaws.
He considered maxillary first permanent molar as fixed anatomical point & as key to occlusion.
He classified three categaries designated as classes & represented by ROMAN numerals I, II and III. ANGLE’S CLASS I : www.rxdentistry.blogspot.com ANGLE’S CLASS I The mesiobuccal cusp of the maxillary first molar occluding in the buccal groove of the mandibular first permanent molar.
The pt. show some dental irregularities like crowding, spacing, rotation missing tooth etc. Slide 18: www.rxdentistry.blogspot.com The mandibular dental arch is in normal mesiodistal relationship of the maxillary arch.
Another category of malocclusion is classified as class I is Bimaxillary Protrsion.(both jaws forwardly placed) ANGLE’S CLASS II : www.rxdentistry.blogspot.com ANGLE’S CLASS II The mesiobuccal cusp of maxillary first permanent molar occlude in the space b/w the mesiobuccal cusp of the mandibular first permanent molar & the distal aspect of the mandibular second premolar.
Also,the mesiolingual cusp of the maxillary first permanent molar occludes mesial to the mesiolingual cusp of the mandibular first permanent molar. Slide 20: www.rxdentistry.blogspot.com Based on the labiolingual angulation of the maxillary incisors angle divided the class II malocclusion into two division-
class II division 1
class II division 2 CLASS II DIVISION 1 : www.rxdentistry.blogspot.com CLASS II DIVISION 1 The maxillary incisor teeth are proclained or labioversion.
Frequently the lower anterior segment shows supraversion or over eruption of the incisor teeth,a tendency towards “flattening” & some irregularities.
The maxillary arch shape become “V” instead of U but seldom normal. Slide 22: www.rxdentistry.blogspot.com Due to proclination of upper anterior there is increase in overjet.
Lower lip cushion to the lingual aspect of the upper teeth
this class associated with abnormal muscle function compare to angle’s class I Slide 23: www.rxdentistry.blogspot.com During swallowing abnormal mentalis activity
& abberent buccinator activity, together with
compensatory muscle function & changed
tongue position tend to accentuate the
narrowing of the maxillary arch,the
protrusion, labial inclination & spacing of the
maxillary incisors, the curve of spee &the
flattening of the mandibular anterior
segment. CLASS II DIVISION 2 : www.rxdentistry.blogspot.com CLASS II DIVISION 2 Along with the typical class II molar relationship the maxillary central incisor are near normal anterioposteriorly or slightly in linguo version,whereas the maxillary lateral incisor are tipped labially and/or mesially. Slide 25: www.rxdentistry.blogspot.com In some cases variation occurs-Both central and lateral incisors may be lingually inclinedand the canines labially inclined.
In contrast with classII div 1 perioral muscle function is usually normal but certain function problems involving temporalis,masseter & lateral pterygoid muscle activity are common. Slide 26: www.rxdentistry.blogspot.com The combination of the lingually inclined maxillary incisors & infraocclusion of the posterior teeth often results in the creation of an abnormal path of closure. (mandible can be forced into a retruded position by tooth guidence.) CLASS II SUBDIVISION : www.rxdentistry.blogspot.com CLASS II SUBDIVISION When a class II molar relationship exist on one side of dental arch & class I on other side it is reffered to subdivision. DIFFERENCE B/W DIV1 & DIV2 : www.rxdentistry.blogspot.com DIFFERENCE B/W DIV1 & DIV2 DIV 1 DIV2 ANGLE’S CLASS III : www.rxdentistry.blogspot.com ANGLE’S CLASS III The mandibular dental arch & body is in mesial relationship to the maxillary arch; with the mesiobuccal cusp of the maxillary first molar occlusion in the interdental space b/w the dental aspect of the distal cusps of the mandibular first molar & the mesial aspect of mesial cusps of the mandibular second molar. Slide 30: www.rxdentistry.blogspot.com In most cases the incisors are inclined excessively to the lingual aspect,despite the crossbite
individual tooth irregularities are frequent.
The space provided for the tongue appears to be greater & the tongue lies on the floor of the mouth most of the time.
The pt can present with a normal overjet, an edge to edge incisor relation on an anterior cross bite. PSEUDO CLASS III : www.rxdentistry.blogspot.com PSEUDO CLASS III This is not a true class III malocclusion but the presentation is similar.
Here the mandible shifts anteriorly in the glenoid fossa due to premature contact of the teeth or some other reason when the jaws are brought together in centric occlusion.
Incidence is low. DIFFERENCE B/W TRUE & PSEUDO CLASS III : www.rxdentistry.blogspot.com DIFFERENCE B/W TRUE & PSEUDO CLASS III DRAWBACKS OF ANGLE’S CLASSIFICATION : www.rxdentistry.blogspot.com DRAWBACKS OF ANGLE’S CLASSIFICATION 1) Angle presumed the first permanent molars as fixed points within the jaws, which definitely is not so
2)Angle depended exclusively on the first molars. Hence, the classification is not possible if the first molars are missing or in the deciduous dentition
3) malocclusion are considered only in the anteroposterior plane. Malocclusion in the transverse & vertical planes are not considered
4) individual tooth malocclusion have not been considered
5) there is no differentiation b/w skeletal & dental malocclusion
6) etiology of malocclusion has not been eleborated upon. DEWEY’S MODIFICATION OF ANGLE’S CLASSIFICATION : www.rxdentistry.blogspot.com DEWEY’S MODIFICATION OF ANGLE’S CLASSIFICATION Dewey in 1915 modified angle’s class I & class III by segregating malposition of anterior and posterior segments as:- MODIFICATION OF ANGLE’S CLASS I : www.rxdentistry.blogspot.com MODIFICATION OF ANGLE’S CLASS I TYPE 1:-Angle’s classI with crowded maxillary anterior teeth. Slide 36: www.rxdentistry.blogspot.com TYPE 2:- Angle’s class I with maxillary incisor in labio-version (proclined) Slide 37: www.rxdentistry.blogspot.com TYPE 3:- Angle’s class I with maxillary incisor teeth on linguo-version to mandibular incisor teeth.(anterior in cross bite) Slide 38: www.rxdentistry.blogspot.com TYPE 4:- Molar and/or premolars are in bucco or linguo-version,but incsors & canines are in normal alignment.(posterior in crossbite) Slide 39: www.rxdentistry.blogspot.com TYPE 5:- Molars are in mesioversion due to early loss of teeth mesial to them.(Early loss of deciduous molars or second premolar) MODIFICATIONS OF ANGLE’S CLASS III : www.rxdentistry.blogspot.com MODIFICATIONS OF ANGLE’S CLASS III TYPE 1:- Individual arches when viewed individually are in normal alignment, but when in occlusion the anterior are in edge to edge bite. Slide 41: www.rxdentistry.blogspot.com TYPE 2:- The mandibular incisors are crowed & lingual to the maxillary incisors. Slide 42: www.rxdentistry.blogspot.com TYPE 3:- Maxillary arch is underdeveloped,in cross bite with maxillary incisors crowded & the mandibular arch is well developed & well aligned. LISCHER’S MODIFICATIONS OF ANGLE’S CLASSIFICATION : www.rxdentistry.blogspot.com LISCHER’S MODIFICATIONS OF ANGLE’S CLASSIFICATION Lischer in 1933 further modified angle’s classification by substitute names for angle”s class I, II& III malocclusion
he also proposed terms to designate individual tooth malpositions
3) Mesioocclusion Slide 44: www.rxdentistry.blogspot.com LISCHER’S NOMENCLATURE FOR INDIVIDUAL TOOTH MALPOSITIONS:-
Lischer add the suffix “version” to a word to indicate the deviation from normal position
1)MESIOVERSION Slide 45: www.rxdentistry.blogspot.com 2) DISTOVERSION
3) LINGUOVERSION Slide 46: www.rxdentistry.blogspot.com 4) LABIOVERSION
5)INFRAVERSION Slide 47: www.rxdentistry.blogspot.com 6) SUPRAVERSION
7) AXIVERSION Slide 48: www.rxdentistry.blogspot.com 8) TORSIVERSION
9) TRANSVERSION BENNETT’S CLASSIFICATION : www.rxdentistry.blogspot.com BENNETT’S CLASSIFICATION Based on their etiology
CLASS I:- Abnormal location of one or more teeth due to local disturbance
CLASS II:- Abnormal formation of a part or a whole of either arch due to developmental defects of bone
CLASS III:-Abnormal relationship b/w the upper & lower archs and b/w either arch & the facial contour,due to developmental defects of bone. SIMON’S CLASSIFICATION : www.rxdentistry.blogspot.com SIMON’S CLASSIFICATION Simon in 1930 was the first to relate the dental arches to the face & cranium in the three planes of space-
i.e. .Frankfort horizontal plane
.Raphe or Median Sagital plane FRANKFORT HORIZONTAL PLANE (VERTICALLY) : www.rxdentistry.blogspot.com FRANKFORT HORIZONTAL PLANE (VERTICALLY) F-H plane is determined by drawing a straight line through the margins of the bony orbit directly under the pupil of the eye to the upper margins of the external auditory meatus. Slide 52: www.rxdentistry.blogspot.com This plane is used to classify malocclusion and vertical deviation with respect to the plane are:-
1.ATTRACTIONS:-When the dental archor part of this is closer to the F-H plane is reffered to attraction.
2.ABSTRACTION:- When a dental arch or part of it is further away from the F-H plane it is reffered to as abstruction. ORBITAL PLANE (ANTEROPOSTERIORLY) : www.rxdentistry.blogspot.com ORBITAL PLANE (ANTEROPOSTERIORLY) This plane is perpendicular to the F-H plane at the margins of bony orbit directly under the pupil of the eye.
This plane should pass through the distal third of the upper canine.(simon’s law of canine) Slide 54: www.rxdentistry.blogspot.com 1. PROTRACTION:- the teeth one or both dental arches and/or jaws are too far forward i.e. placed forward or anterior to the plane.
2. RETRACTION:- the teeth one or both dental arches and/or jaws are too far backward, i.e. placed posterior to the plane than normal MEDIAN SAGITAL PLANE (TRANSVERSE) : www.rxdentistry.blogspot.com MEDIAN SAGITAL PLANE (TRANSVERSE) The plane is determined by the approximately 1.5 cm. apart on the median raphe of the palate. Slide 56: www.rxdentistry.blogspot.com Malocclusion classified according to transverse deviation as:
1. CONTRACTION:- A part or all of the dental arch is contracted towards the median sagittal plane.
2.DISTRACTION:- A part or all of the dental arch is wider or placed at a distance which is more than normal. SKELETAL CLASSIFICATION : www.rxdentistry.blogspot.com SKELETAL CLASSIFICATION SALZMANN in 1950 was the first to classify malocclusion on skeletal structure basis.
Skeletal class 1
Skeletal class 2
Skeletal class 3 SKELETAL CLASS 1 : www.rxdentistry.blogspot.com SKELETAL CLASS 1 These malocclusion were purely dental with the bones of the face & jaws being in harmony with one another & with the rest of the head.
The profile is orthognathic
DIV 3 Slide 59: www.rxdentistry.blogspot.com DIVISION 1:- Local malrelations of incisors,canine and premolars. Slide 60: www.rxdentistry.blogspot.com DIVISION 2:- Maxillary incisors protrusion Slide 61: www.rxdentistry.blogspot.com DIVISION 3:- Maxillary incisors in linguoversion Slide 62: www.rxdentistry.blogspot.com DIVISION 4:- Bimaxillary protrusion. SKELETAL CLASS 2 : www.rxdentistry.blogspot.com SKELETAL CLASS 2 These include malocclusion with a subnormal distal mandibular development in relation to the maxilla.
It further divided into two division based on features with a retrudedly placed mandible.
DIV 2 Slide 64: www.rxdentistry.blogspot.com DIVISION 1:- the maxillary dental arch is narrower with crowding in the canine region, cross bite may be present and the vertical face height is decreased.
The profile is retrognathic.
DIVISION 2:- the maxillary incisors are lingually inclined,the lateral incisors may be normal or in labioversion. SKELETAL CLASS 3 : www.rxdentistry.blogspot.com SKELETAL CLASS 3 Here there is an overgrowth of the mandible with an obtuse angle.
The profile is prognathic. ACKERMAN-PROFITT SYSTEM OF CLASSIFICATION : www.rxdentistry.blogspot.com ACKERMAN-PROFITT SYSTEM OF CLASSIFICATION Proposed a very comprehensive system of classification which includes malocclusions in three planes of space tended to give an indication towards the severity of malocclusion.
The system based on a set theory,where a set is defined on the basis of morphologic deviations from the ideal. Slide 67: www.rxdentistry.blogspot.com The classification was illustrated using the VENN SYMBOLIC LOGIC diagram.
The classification consists 9 groups and 5 characteristics or steps with in.
The steps are:- Slide 68: www.rxdentistry.blogspot.com CHARACTERSTIC 1 (ALIGNMENT)
Intraarch alignment and symmetry are assessed as when seen in the occlusal view.
Classified as ideal/crowded/spaced.
CHARACTERSTIC 2 (PROFILE)
Profile can be convex/straight/concave
it also includes the facial divergence anterior or posterior divergence. Slide 69: www.rxdentistry.blogspot.com CHARACTERSTIC 3:- (TRANSVERSE RELATIONSHIPS/TYPE)
Buccal or palatal cross bites are noted
further subclassified as unilateral/bilateral
skeletal/dental cross bites Slide 70: www.rxdentistry.blogspot.com CHARACTERSTICS 4:- (CLASS)
here sagittal relationships of the teeth is assessed using the angle’s class I/class II/ class III.
Distinction b/w skeletal/dental
here malocclusion are assessed in the vertical plane.
They are described as anterior openbite/posterior openbite/anterior deepbite/posterior collapsed bite.
Skeletal or dental. Slide 71: www.rxdentistry.blogspot.com Slide 72: www.rxdentistry.blogspot.com GROUP 1:- Repersented as the outer envelop or universe.since the degree of alignment & symmetry are common to all dentitions.
GROUP 2:- the profile is affected by many malocclusions so it becomes a major set with in the universe.
GROUP 3-9:- Deviations in three planes of space are represented by group 3-9 which includes the overlapping or interlocking subsets,all with in the profile. Slide 73: www.rxdentistry.blogspot.com Group 9:- would be more severe with involvement of criteria from all groups.
ALIGNMENT : both arches crowed
PROFILE : posteriorly
TYPE : maxillary palatal crossbite,
bilateral skeletal & dental
CLASS : class I,excessive overjet,
class II dental & skeletal
BITE DEPTH : open bite skeletal INDIVIDUAL TOOTH CLASSIFICATIONS : www.rxdentistry.blogspot.com INDIVIDUAL TOOTH CLASSIFICATIONS INCISOR CLASSIFICATION
CANINE CLASSIFICATION INCISOR CLASSIFICATION : www.rxdentistry.blogspot.com INCISOR CLASSIFICATION Simple & more relevent than Angle’s classification.
Adopted by british standard institute in 1983
based upon the lower incisal edges & the cingulam plateu of the maxillary central incisors. Slide 76: www.rxdentistry.blogspot.com CLASS I:- The lower incisor edges occlude with or lie immediately below the cingulam plateu of the max.central incisors.
CLASS 2:- The lower incisor edges lie posterior to thecingulam plateu of the max.central incisors.
DIV 2 Slide 77: www.rxdentistry.blogspot.com DIVISION 1:- The maxillary CI are proclaimed or of average inclination & there is increase over jet.
DIVISION 2:- The maxillary CI are retroclained, the overbite is normally minimum but may be increased. Slide 78: www.rxdentistry.blogspot.com CLASS 3:- The man. incisor edge lie anterior to the cingulam plateu of the upper CI the over jet is reduced or reversed CANINE CLASSIFICATION : www.rxdentistry.blogspot.com CANINE CLASSIFICATION CLASS I :- mesial incline of the upper canine overlaps the distal slope of the lower canine.
CLASS II:- Distal slope of the max.canine occludes or contact the mesial slope of the lower canine.
CLASS III:- The lower canine is displaced anterior to the upper canine with no overlapping of the upper & lower canine.