Mal Occlusion / orthodontic courses by Indian dental academy

CLASSIFICATION CLASSIFICATION OF OF

MALOCCLUSIONMALOCCLUSION

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IntroductionIntroduction

Normality is the basis of classification in Normality is the basis of classification in orthodontics. It rests on what is known as biologic orthodontics. It rests on what is known as biologic continuity, i.e., the most frequently found relationship continuity, i.e., the most frequently found relationship of the teeth and of the bones of the face in relation to of the teeth and of the bones of the face in relation to each other and to the skull as a whole.each other and to the skull as a whole.

Malocclusion is any perversion of normal Malocclusion is any perversion of normal occlusion of the teeth. It is a condition where there is occlusion of the teeth. It is a condition where there is departure from the normal relation of the teeth to other departure from the normal relation of the teeth to other teeth in the same arch and to the teeth in the opposing teeth in the same arch and to the teeth in the opposing arch. arch.


INTRODUCTIOINTRODUCTIONN

In order to acquire a better understanding of the In order to acquire a better understanding of the many deviations from normal occlusion and to assist many deviations from normal occlusion and to assist in diagnosis and treatment planning, it becomes in diagnosis and treatment planning, it becomes necessary to group the varieties of malocclusion into necessary to group the varieties of malocclusion into order. This is difficult as occlusal anomalies are many order. This is difficult as occlusal anomalies are many and varied. Orthodontics has been described, and varied. Orthodontics has been described, admirably, as a ‘Science of Infinite Variations’.admirably, as a ‘Science of Infinite Variations’.


DEFINITION DEFINITION Classification is a process of analyzing cases of Classification is a process of analyzing cases of

malocclusion for the purpose of segregating them into malocclusion for the purpose of segregating them into a small number of groups, which groups are a small number of groups, which groups are characterized by certain specific and fundamental characterized by certain specific and fundamental variations from normal occlusion of the teeth.variations from normal occlusion of the teeth.


OBJECTIVESOBJECTIVES Classification is an essential communication tool Classification is an essential communication tool between dental school professor and student, between between dental school professor and student, between practitioners, and between practitioner and insurance practitioners, and between practitioner and insurance company or government bureaucracy. It is essential company or government bureaucracy. It is essential that everyone "speak the same language." that everyone "speak the same language." Classification aids in the diagnosis and treatment Classification aids in the diagnosis and treatment planning of malocclusions by orienting the clinician planning of malocclusions by orienting the clinician to the type and the magnitude of the problems and to the type and the magnitude of the problems and possible mechanical solutions to the problems. possible mechanical solutions to the problems.


OBJECTIVESOBJECTIVES Segregation of the countless number of cases of Segregation of the countless number of cases of tooth malposition into a comparatively low number of tooth malposition into a comparatively low number of groups, each group containing only such cases as are groups, each group containing only such cases as are characterized by a common factor or factors of characterized by a common factor or factors of fundamental significance. fundamental significance. Ease of reference i.e. giving name to a group of Ease of reference i.e. giving name to a group of symptoms making together a single problem symptoms making together a single problem Comparison of cases with other cases having same Comparison of cases with other cases having same problemproblem


GENERAL GENERAL CLASSIFICATIOCLASSIFICATIONN Malocclusion can be broadly divided into-Malocclusion can be broadly divided into-

Individual tooth malposition or Intra arch malocclusionIndividual tooth malposition or Intra arch malocclusion Maxillo-mandibular malocclusions or Inter arch Maxillo-mandibular malocclusions or Inter arch

malocclusionmalocclusion


GENERAL GENERAL CLASSIFICATIOCLASSIFICATIONN

Individual tooth malposition or Intra arch Individual tooth malposition or Intra arch malocclusionmalocclusion

A tooth can be abnormally related to its neighboring A tooth can be abnormally related to its neighboring teeth, such abnormal variations are called individual teeth, such abnormal variations are called individual tooth malpositions or intra arch malpositions. Some of tooth malpositions or intra arch malpositions. Some of the commonly seen individual tooth malpositions arethe commonly seen individual tooth malpositions are

Distal inclination or distal tipping Distal inclination or distal tipping Mesial inclination or mesial tippingMesial inclination or mesial tipping Lingual inclination or lingual tippingLingual inclination or lingual tipping Buccal inclination or buccal tippingBuccal inclination or buccal tipping



Individual tooth malposition or Intra arch Individual tooth malposition or Intra arch malocclusionmalocclusion

Mesial displacementMesial displacement Distal displacementDistal displacement Lingual displacementLingual displacement Buccal displacementBuccal displacement Infraversion or infraocclusionInfraversion or infraocclusion Supraversion or supra occlusionSupraversion or supra occlusion Disto lingual or mesio buccal rotationDisto lingual or mesio buccal rotation Mesio lingual or disto buccal rotationMesio lingual or disto buccal rotation TranspositionTransposition



MESIAL MESIAL INCLINATIONINCLINATION

DISTAL DISTAL INCLINATIONINCLINATION

LINGUAL AND LABIAL LINGUAL AND LABIAL INCLINATIONINCLINATION

MESIAL MESIAL DISPLACEMENTDISPLACEMENT

DISTAL DISTAL DISPLACEMENTDISPLACEMENT



INFRAVERSIONINFRAVERSION SUPRAVERSIONSUPRAVERSION LINGUAL AND LABIAL LINGUAL AND LABIAL DISPLACEMENTDISPLACEMENT

TORSIVERSIONTORSIVERSION TRANSPOSITIONTRANSPOSITION



Inter arch malocclusionsInter arch malocclusionsThese malocclusions are characterized by These malocclusions are characterized by

abnormal relationships between two teeth or groups of abnormal relationships between two teeth or groups of teeth of one arch to the other arch. These inter arch teeth of one arch to the other arch. These inter arch malocclusion can occur in malocclusion can occur in

Sagital planeSagital plane Vertical planeVertical plane Transverse planeTransverse plane



Sagital plane malocclusions Sagital plane malocclusions Pre-normal occlusion-Pre-normal occlusion- refers to a condition where the refers to a condition where the lower arch is more forwardly placed when the patient lower arch is more forwardly placed when the patient bites in centric occlusion. bites in centric occlusion.

Post-normal occlusion-Post-normal occlusion- a condition where the lower a condition where the lower arch is more distally placed when the patient bites in arch is more distally placed when the patient bites in centric occlusion.centric occlusion.



Vertical plane malocclusionsVertical plane malocclusionsDeep bite or increased over biteDeep bite or increased over bite: this refers to a : this refers to a condition where there is an excessive vertical overlap condition where there is an excessive vertical overlap between upper and lower anterior teeth.between upper and lower anterior teeth.

Open biteOpen bite: is a condition where there is no vertical : is a condition where there is no vertical overlap between upper and lower teeth . Thus a space overlap between upper and lower teeth . Thus a space exist between the upper and lower teeth when the patient exist between the upper and lower teeth when the patient bites in centric occlusion. Open bite can be in bites in centric occlusion. Open bite can be in anterioranterior or or posteriorposterior region region..



Transverse plane malocclusionsTransverse plane malocclusionsCross biteCross bite – refers to a condition in which mandibular – refers to a condition in which mandibular teeth overlap their maxillary antagonists. Cross bite can teeth overlap their maxillary antagonists. Cross bite can be be anterior anterior or or posteriorposteriorBuccal Non occlusion – Buccal Non occlusion – refers to a condition in which refers to a condition in which maxillary posteriors are completely buccally placed in maxillary posteriors are completely buccally placed in relation to mandibular antagonists without occludingrelation to mandibular antagonists without occluding

Palatal Non occlusionPalatal Non occlusion – refers to a condition in which – refers to a condition in which maxillary posteriors are completely palatally placed in maxillary posteriors are completely palatally placed in relation to mandibular antagonists without occludingrelation to mandibular antagonists without occluding


ANGLE’S ANGLE’S CLASSIFICATIOCLASSIFICATIONN

Angle believed that since biologic entities as Angle believed that since biologic entities as well as inanimate elements can be arranged into well as inanimate elements can be arranged into well-defined classes, the same held also of the well-defined classes, the same held also of the occlusion of the teeth and the shape of the face. occlusion of the teeth and the shape of the face. Angle based his classification of malocclusion on Angle based his classification of malocclusion on the normal mesiodistal relations of the mesiobuccal the normal mesiodistal relations of the mesiobuccal cusps of the upper first molars in relation to the cusps of the upper first molars in relation to the mandibular first molars.mandibular first molars.



Basis for Angle’s classificationBasis for Angle’s classification Most indicative irregularity of teeth found in antero-posterior Most indicative irregularity of teeth found in antero-posterior relationship of the teeth and the jaws.relationship of the teeth and the jaws. There is a normal mesio distal or antero-posterior position for the There is a normal mesio distal or antero-posterior position for the body of the mandible with its superimposed mandibular dental arch body of the mandible with its superimposed mandibular dental arch to occupy in the anatomy of the skull.to occupy in the anatomy of the skull. The maxillary dental arch being built upon a base that is a fixed The maxillary dental arch being built upon a base that is a fixed section of the skull anatomy, is more or less stable in its relationship section of the skull anatomy, is more or less stable in its relationship to various landmarks on the head and consequently the first molar to various landmarks on the head and consequently the first molar teeth in this arch may be quite safely selected as a key tooth from teeth in this arch may be quite safely selected as a key tooth from which to judge the relationship of mandibular dental arch and which to judge the relationship of mandibular dental arch and intern to the body of mandible upon which it is locatedintern to the body of mandible upon which it is located



Basis for Angle’s classificationBasis for Angle’s classification If there is shifting of maxillary molars in their If there is shifting of maxillary molars in their relationship to the skull anatomy, this variation can be relationship to the skull anatomy, this variation can be detected by changes in the axial inclination of teeth in detected by changes in the axial inclination of teeth in the maxillary arch. The axial change is especially the maxillary arch. The axial change is especially manifested by canine teeth.manifested by canine teeth.

Curvature and line of occlusion is unique to each Curvature and line of occlusion is unique to each individualindividual..



Angle used the Roman numerals I, II and Angle used the Roman numerals I, II and III to designate the three main classes of mesiodistal III to designate the three main classes of mesiodistal arch relationship viz., Class I or normal, Class II or arch relationship viz., Class I or normal, Class II or distal and Class III or mesial relationship of the cusps of distal and Class III or mesial relationship of the cusps of the mandibular first molars to the maxillary first molars.the mandibular first molars to the maxillary first molars.

He employed the Arabic numerals 1 and He employed the Arabic numerals 1 and 2 to denote divisions of the classifications. Unilateral 2 to denote divisions of the classifications. Unilateral deviations he termed subdivisions. deviations he termed subdivisions.



Angle classified malocclusion as Angle classified malocclusion as followsfollows

Class IClass I

Class IIClass IIDivision 1Division 1

Division IIDivision IISubdivisionSubdivision

Class IIIClass IIISubdivisionSubdivision



Class I MalocclusionClass I MalocclusionThe mandibular dental arch and the body of the The mandibular dental arch and the body of the mandible are in normal relation to the maxillary arch mandible are in normal relation to the maxillary arch indicated by the fact that mesiobuccal cusp of the indicated by the fact that mesiobuccal cusp of the maxillary first permanent molar occludes in the buccal maxillary first permanent molar occludes in the buccal groove of the mandibular permanent first molar and groove of the mandibular permanent first molar and the mesiolingual cusp of the maxillary first molar the mesiolingual cusp of the maxillary first molar occludes with the occlusal fossa of the mandibular first occludes with the occlusal fossa of the mandibular first permanent molar when the jaws are in centric permanent molar when the jaws are in centric occlusionocclusion





Class II MalocclusionClass II MalocclusionThe mandibular dental arch and the body of the The mandibular dental arch and the body of the mandible are in distal relation to the maxillary arch by mandible are in distal relation to the maxillary arch by half the width of the maxillary first permanent molar half the width of the maxillary first permanent molar or mesioodistal width of a premolar indicated by the or mesioodistal width of a premolar indicated by the fact that mesiobuccal cusp of the maxillary first fact that mesiobuccal cusp of the maxillary first permanent molar occludes in the space between the permanent molar occludes in the space between the mesiobuccal cusp of the mandibular permanent first mesiobuccal cusp of the mandibular permanent first molar and the buccal cusp of the second premolar.molar and the buccal cusp of the second premolar.



Class II MalocclusionClass II MalocclusionThe mesiolingual cusp of the maxillary first molar The mesiolingual cusp of the maxillary first molar occludes mesial to the mesiolingual cusp of the occludes mesial to the mesiolingual cusp of the mandibular first permanent molar when the jaws are in mandibular first permanent molar when the jaws are in centric occlusioncentric occlusion..





Class II MalocclusionClass II MalocclusionDivision IDivision I

A class II malocclusion in which maxilary incisors A class II malocclusion in which maxilary incisors are in labioversionare in labioversion

Subdivision Subdivision

A class II division I malocclusion occuring on A class II division I malocclusion occuring on only one sideonly one side



Class II MalocclusionClass II MalocclusionDivision IIDivision II

A class II malocclusion in which maxilary incisors A class II malocclusion in which maxilary incisors are not in labioversion rather they are retroclined are not in labioversion rather they are retroclined with laterals overlapping centrals or canines with laterals overlapping centrals or canines overlapping lateralsoverlapping laterals

Subdivision Subdivision

A class II division I malocclusion occuring on A class II division I malocclusion occuring on only one sideonly one side



Class III MalocclusionClass III MalocclusionThe mandibular dental arch and the body of the The mandibular dental arch and the body of the mandible are in mesial relationship to the maxillary mandible are in mesial relationship to the maxillary arch indicated by the fact that mesiobuccal cusp of the arch indicated by the fact that mesiobuccal cusp of the maxillary first permanent molar occludes in the maxillary first permanent molar occludes in the interdental space between the distal aspect of the distal interdental space between the distal aspect of the distal cusp of the mandibular first permanent molar and the cusp of the mandibular first permanent molar and the mesial aspect of the mesial cusp of the second mesial aspect of the mesial cusp of the second permanent molarpermanent molar





Class III MalocclusionClass III MalocclusionSubdivisionSubdivision

A class III malocclusion in which malocclusion is A class III malocclusion in which malocclusion is only unilaterallyonly unilaterally



Pseudo-Class III MalocclusionPseudo-Class III MalocclusionIn this condition the mandible is protruded a little during In this condition the mandible is protruded a little during the final stages of closure in order to avoid a premature the final stages of closure in order to avoid a premature contact of incisors or caninescontact of incisors or canines

This is most likely to arise in cases where the relationship This is most likely to arise in cases where the relationship of the incisors is edge-to-edge, and may be caused by a of the incisors is edge-to-edge, and may be caused by a mildly prenormal relationship of the dental basesmildly prenormal relationship of the dental bases

Such pseudo – or postural Class III cases may tend, if Such pseudo – or postural Class III cases may tend, if left untreated, to become established by a further left untreated, to become established by a further development of the whole occlusion in Class III relation.development of the whole occlusion in Class III relation.


Features True Class III Pseudo Class III

1 Profile Concave Straight to concave

2 Etiology Hereditary Habitual/developmental

3 Premature contacts

Absent Present

4 Path of closure Forward Deviated

5 Gonial angle Increased/decreased Normal

6 Retrusion of mandible further

Not possible Possible

7 Treatment Orthopedic or surgical

Elimination of prematurities, replacement of lost posterior

teeth8 Left untreated No further changes Becomes established into true

class III

Differences between true and pseudo class III malocclusionDifferences between true and pseudo class III malocclusion



Drawbacks of Angle’s ClassificationDrawbacks of Angle’s ClassificationThe Angle classification was readily The Angle classification was readily

accepted by the dental profession, since it brought order accepted by the dental profession, since it brought order out of what previously had been confusion regarding out of what previously had been confusion regarding dental relationships. It was recognized almost dental relationships. It was recognized almost immediately, however, that there were deficiencies in the immediately, however, that there were deficiencies in the Angle system.Angle system.



Drawbacks of Angle’s ClassificationDrawbacks of Angle’s ClassificationAngle considered malocclusion only in antero-posterior Angle considered malocclusion only in antero-posterior planeplane

Angle considered maxillary first permanent molar as a Angle considered maxillary first permanent molar as a fixed point but it was not found sofixed point but it was not found so

The classification cannot be applied if first permanent The classification cannot be applied if first permanent molars are missing or extractedmolars are missing or extracted

The classification cannot be applied in the deciduous The classification cannot be applied in the deciduous dentitiondentition



Drawbacks of Angle’s ClassificationDrawbacks of Angle’s ClassificationThe classification does not differentiates between The classification does not differentiates between skeletal and dental malocclusionsskeletal and dental malocclusions

The classification does not highlight the etiology of the The classification does not highlight the etiology of the malocclusion malocclusion

Individual tooth malpositions have not been considered Individual tooth malpositions have not been considered in the classificationin the classification


LISCHER’S LISCHER’S CLASSIFICATIOCLASSIFICATIONN

Lischer introduced the following terms which are Lischer introduced the following terms which are widely used to describe the varieties of malocclusion. He widely used to describe the varieties of malocclusion. He substituted the term Class I, Class II, Class III given by substituted the term Class I, Class II, Class III given by angle with the terms Neurtro-occlusion, Disto-occlusion and angle with the terms Neurtro-occlusion, Disto-occlusion and

Mesio-occlusionMesio-occlusion..



Neutro-occlusion: Normal relation of dental Neutro-occlusion: Normal relation of dental arches. It is synonymous with Angle’s Class I arches. It is synonymous with Angle’s Class I malocclusion.malocclusion.Disto-occlusion: Synonymous with Angle’s Class Disto-occlusion: Synonymous with Angle’s Class II, used to describe all cases of post-normal II, used to describe all cases of post-normal occlusion.occlusion.Mesio-occlusion: Synonymous with Angle’s Mesio-occlusion: Synonymous with Angle’s Class III and describes all cases of prenormal Class III and describes all cases of prenormal occlusion.occlusion.



He gave the suffix “version” to describe the He gave the suffix “version” to describe the wrong position of individual teeth as follows:wrong position of individual teeth as follows:

Linguo version—Lingual placement Linguo version—Lingual placement Labio version—Labial placementLabio version—Labial placementMesio version—Mesial placementMesio version—Mesial placementDisto version—Distal placementDisto version—Distal placementInfra version—Intrusion of teethInfra version—Intrusion of teethSupra version—Extrusion of teeth Supra version—Extrusion of teeth Torsiversion—Rotation Torsiversion—Rotation Perversion—Impacted toothPerversion—Impacted tooth


Dewey’s Dewey’s Modification of Modification of Angle’s Angle’s ClassificationClassificationDewey proposed a modification of Dewey proposed a modification of

the Angle’s classification of malocclusion. He the Angle’s classification of malocclusion. He divided the Angle’s class I into five types and divided the Angle’s class I into five types and Angle’s Class III into three types. There were no Angle’s Class III into three types. There were no modifications for Class II. He considered the modifications for Class II. He considered the same molar relationship as in Angle’s same molar relationship as in Angle’s classificationclassification


Dewey’s Dewey’s Modification of Modification of Angle’s Angle’s ClassificationClassificationModification of Angle’s Class IModification of Angle’s Class I

Type 1Type 1. Bunched or crowded maxillary anterior teeth. . Bunched or crowded maxillary anterior teeth. The canines may be in labioversion or infraversion. All The canines may be in labioversion or infraversion. All other versions of individual teeth may be presentother versions of individual teeth may be present

Type 2. Type 2. Maxillary incisors in labioversionMaxillary incisors in labioversion Type 3Type 3. The maxillary incisor teeth are in linguoversion . The maxillary incisor teeth are in linguoversion

to the mandibular incisorsto the mandibular incisors Type 4Type 4. The molars, occasionally also premolars are in . The molars, occasionally also premolars are in

linuoversion or labiobversion but canines and incisors linuoversion or labiobversion but canines and incisors are in normal relationare in normal relation

Type 5Type 5. The molars are in mesioversion due to shifting . The molars are in mesioversion due to shifting following loss of teeth anterior to molarsfollowing loss of teeth anterior to molars


Dewey’s Dewey’s Modification of Modification of Angle’s Angle’s ClassificationClassificationModification of Angle’s Class IIIModification of Angle’s Class III

Type 1Type 1. The dental arches are well formed and the teeth . The dental arches are well formed and the teeth are in normal alignment when viewed individually but are in normal alignment when viewed individually but there is edge-to-edge bite in anterior regionthere is edge-to-edge bite in anterior region

Type 2. Type 2. The mandibular incisors are crowded and in The mandibular incisors are crowded and in lingual relation to the maxillary incisorslingual relation to the maxillary incisors

Type 3Type 3. The maxillary arch is underdeveloped. The . The maxillary arch is underdeveloped. The maxillary incisor are crowded. The mandibular arch is maxillary incisor are crowded. The mandibular arch is well developed and the mandibular teeth are in normal well developed and the mandibular teeth are in normal aligmentaligment


BENNET’S BENNET’S CLASSIFICATIOCLASSIFICATIONN

Sir Norman Bennett introduced a classification of Sir Norman Bennett introduced a classification of abnormalities of occlusion which was based on their etiology. abnormalities of occlusion which was based on their etiology. Briefly the classification is as follows:Briefly the classification is as follows:

Class I - Abnormal position of one or more teeth due to local Class I - Abnormal position of one or more teeth due to local causes.causes.

Class II - Abnormal formation of a part or whole of either arch Class II - Abnormal formation of a part or whole of either arch due to developmental defects of bone.due to developmental defects of bone.

Class III- Abnormal relationship between upper and lower Class III- Abnormal relationship between upper and lower arches, and between either arch and facial contour and arches, and between either arch and facial contour and correlated abnormal formation of either arch.correlated abnormal formation of either arch.


SIMON’S SIMON’S CLASSIFICATIOCLASSIFICATIONN

Since growth of the face and jaws occurs in the three Since growth of the face and jaws occurs in the three planes of space-height, width and depth, abnormalities also planes of space-height, width and depth, abnormalities also occur in any one or more of the foregoing planes. occur in any one or more of the foregoing planes.

Simon’s craniometric classification relates the denture Simon’s craniometric classification relates the denture to the face and cranium in the three planes of space, to the face and cranium in the three planes of space,

(1) The Frankfort horizontal (1) The Frankfort horizontal

(2) The Orbital plane and (2) The Orbital plane and

(3) The raphe or median sagittal plane.(3) The raphe or median sagittal plane.



The Frankfort horizontal plane The Frankfort horizontal plane

The Frankfort horizontal plane or the eye-ear The Frankfort horizontal plane or the eye-ear plane is determined by drawing a straight line through the plane is determined by drawing a straight line through the margin of the bony orbit directly under the pupil of the eye, to margin of the bony orbit directly under the pupil of the eye, to the upper margin of the auditory meatus (the notch above the the upper margin of the auditory meatus (the notch above the tragus of the ear). This plane is used to determine deviations in tragus of the ear). This plane is used to determine deviations in the height of the dental arches and teeth in relation to the face the height of the dental arches and teeth in relation to the face and cranium.and cranium.



The Frankfort horizontal plane The Frankfort horizontal plane



The Orbital planeThe Orbital plane

The orbital plane is a perpendicular at right The orbital plane is a perpendicular at right angles to the eye-ear plane at the margin of the bony orbit angles to the eye-ear plane at the margin of the bony orbit directly under the pupil of the eye. This plane is used to directly under the pupil of the eye. This plane is used to determine sagittal deviations of the dental arches and the axial determine sagittal deviations of the dental arches and the axial inclination of the teeth to the face and the cranium.inclination of the teeth to the face and the cranium.



The Orbital planeThe Orbital plane



The Raphe or Median Sagittal planeThe Raphe or Median Sagittal plane

The Raphe or Median Sagittal plane is The Raphe or Median Sagittal plane is determined by points approximately 1.5 cm apart on the median determined by points approximately 1.5 cm apart on the median raphe of the palate. The raphe median plane passes through raphe of the palate. The raphe median plane passes through these two points at right angles to the Frankfort horizontal these two points at right angles to the Frankfort horizontal plane. This plane is used to determine the deviations in the plane. This plane is used to determine the deviations in the general form and width of the dental arches and the axial general form and width of the dental arches and the axial inclination of the teeth in relation to the midline of the palate inclination of the teeth in relation to the midline of the palate and the headand the head



The Raphe or Median Sagittal planeThe Raphe or Median Sagittal plane



The Law of the CanineThe Law of the Canine

In normal arch relationship, according to Simon, In normal arch relationship, according to Simon, the orbital plane passes through the distal axial aspect of the the orbital plane passes through the distal axial aspect of the canine. This is known as “The law of the canine”.canine. This is known as “The law of the canine”.



Deviation from the raphe or median sagittal plane Deviation from the raphe or median sagittal plane ..

Arch form and inclination of tooth axisArch form and inclination of tooth axis are determined are determined from this plane. from this plane.

ContractionContraction: A part or all of the dental arch is contracted : A part or all of the dental arch is contracted toward the raphe median plane. The abnormality may be toward the raphe median plane. The abnormality may be mandibular, alveolar, dental, anterior, posterior, unilateral mandibular, alveolar, dental, anterior, posterior, unilateral or bilateral. or bilateral.

DistractionDistraction: A part or all of the dental arch is wider than : A part or all of the dental arch is wider than usual from the raphe median planeusual from the raphe median plane



Deviations from the Frankfort horizontal planeDeviations from the Frankfort horizontal plane: :

The angle between the Frankfort horizontal and the The angle between the Frankfort horizontal and the occlusal plane, the form of the occlusal curve, and the occlusal plane, the form of the occlusal curve, and the inclination of the teeth axesinclination of the teeth axes are determined from this plane. are determined from this plane.

AttractionAttraction: The distance between the occlusal plane and : The distance between the occlusal plane and the FH Plane is comparatively shorter than normal. This the FH Plane is comparatively shorter than normal. This distance is as a rule normally shorter in the young than in distance is as a rule normally shorter in the young than in older persons and in some ethnic groups. older persons and in some ethnic groups.

AbstractionAbstraction: The distance between the occlusal plane and : The distance between the occlusal plane and the FH plane is comparatively longer than normal.the FH plane is comparatively longer than normal.



Deviations from the Orbital planeDeviations from the Orbital plane: :

Sagittal symmetry and inclination of the axes of the Sagittal symmetry and inclination of the axes of the teeth are determined from this plane. teeth are determined from this plane.

ProtractionProtraction: The teeth, one or both dental arches, and or : The teeth, one or both dental arches, and or jaws are too far forward. Normally the orbital plane passes jaws are too far forward. Normally the orbital plane passes through the distal incline of the canine. through the distal incline of the canine.

RetractionRetraction: The teeth, one or both dental arches and or : The teeth, one or both dental arches and or jaws are too far retruded. The orbital plane passes too far jaws are too far retruded. The orbital plane passes too far anteriorly to the canines. anteriorly to the canines.



Deviations of the dental arches in relation to the orbital plane, Deviations of the dental arches in relation to the orbital plane, according to Simon, may occur as follows:according to Simon, may occur as follows:

Both the jaws in normal relation to each otherBoth the jaws in normal relation to each other

Upper jaw normal, lower jaw distalUpper jaw normal, lower jaw distal

Upper jaw normal, lower jaw mesialUpper jaw normal, lower jaw mesial

Lower jaw normal, upper jaw mesialLower jaw normal, upper jaw mesial

Lower jaw normal, upper jaw distal Lower jaw normal, upper jaw distal

Upper jaw mesial, lower jaw distalUpper jaw mesial, lower jaw distal

Upper jaw distal, lower jaw mesialUpper jaw distal, lower jaw mesial


SKELETAL SKELETAL CLASSIFICATIOCLASSIFICATIONN

Malocclusion may or may not be associated with facial Malocclusion may or may not be associated with facial dysplasia. Dental malocclusion may be present in an otherwise dysplasia. Dental malocclusion may be present in an otherwise orthognathic face. However, normal occlusion may also be orthognathic face. However, normal occlusion may also be present in a face which is not orthognathic. Facial skeletal present in a face which is not orthognathic. Facial skeletal patterns are divided into patterns are divided into

Class 1, in which the profile is orthognathic, Class 1, in which the profile is orthognathic,

Class 2, where the mandible is retrognathic, and Class 2, where the mandible is retrognathic, and

Class 3, in which the mandible is prognathic.Class 3, in which the mandible is prognathic.



Classification of the facial skeletal pattern takes into Classification of the facial skeletal pattern takes into consideration also the relationship of the teeth as follows:consideration also the relationship of the teeth as follows:

Skeletal Class 1Skeletal Class 1: The bones of the face and the jaws are : The bones of the face and the jaws are in harmony with one another and with the rest of the head. The in harmony with one another and with the rest of the head. The maxilla is slightly ahead of the mandible. The profile is maxilla is slightly ahead of the mandible. The profile is orthognathic. orthognathic.

Division 1. Local malrelations of incisor, canine or Division 1. Local malrelations of incisor, canine or premolar teeth. premolar teeth.

Division 2. Maxillary incisor protrusion. Division 2. Maxillary incisor protrusion.

Division 3. Maxillary incisors in linguoversion.Division 3. Maxillary incisors in linguoversion.

Division 4. Bimaxillary protrusion.Division 4. Bimaxillary protrusion.www.indiandentalacademy.com


Skeletal Class 2Skeletal Class 2: Subnormal distal mandibular : Subnormal distal mandibular development in relation to the maxilla.development in relation to the maxilla.

Division 1. Maxillary dental arch is narrower than Division 1. Maxillary dental arch is narrower than mandibular and there is crowding in the mandibular and there is crowding in the

canine canine region, crossbite and reduced vertical region, crossbite and reduced vertical height. height. Protrusion of the maxillary anterior Protrusion of the maxillary anterior teeth. The teeth. The profile is retrognathic. profile is retrognathic.

Division 2. Lingual inclination of the maxillary incisors. Division 2. Lingual inclination of the maxillary incisors. The lateral incisors may be normal or in The lateral incisors may be normal or in

labioversion. labioversion.



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


ACKERMAN – ACKERMAN – PROFFIT PROFFIT CLASSIFICATIONCLASSIFICATION

Ackerman and Proffit proposed a classification scheme Ackerman and Proffit proposed a classification scheme for malocclusions in which five characteristics and their for malocclusions in which five characteristics and their interrelationships are assessed. interrelationships are assessed.

This system is a synthesis of two schemes, the Angle This system is a synthesis of two schemes, the Angle classification and the Venn diagram, both of which were classification and the Venn diagram, both of which were proposed late in the nineteenth century by Angle and Venn.proposed late in the nineteenth century by Angle and Venn.

Venn proposed this representation in 1880, and it has Venn proposed this representation in 1880, and it has become prominent in symbolic logic for computer use. become prominent in symbolic logic for computer use.


INTRA ARCH INTRA ARCH ALIGNMENTALIGNMENT

IDEALIDEALCROWDINGCROWDINGSPACINGSPACING

PROFILEPROFILE

GROUP 1GROUP 1GROUP 2GROUP 2

GROUP 3GROUP 3 GROUP 4GROUP 4

GROUP 5GROUP 5

Gp6Gp6

Gp7Gp7Gp8Gp8

Gp9Gp9

VERTICAL DEVIATIONVERTICAL DEVIATIONOpen Bite anteriorOpen Bite anteriorOpen bite posteriorOpen bite posteriorDeep bite anteriorDeep bite anteriorCollapsed bite posteriorCollapsed bite posteriorSkeletalSkeletalDentalDental

Anterior Anterior divergentdivergentPosterior Posterior divergentdivergentConvexConvexConcaveConcaveStraightStraight

TRANSVERSE TRANSVERSE DEVIATIONDEVIATION

Cross bitesCross bitesBuccalBuccalPalatalPalatalUnilateralUnilateralBilateralBilateralSkeletalSkeletalDental Dental

SAGITTAL SAGITTAL DEVIATIONDEVIATION

Class IClass IClass II Div1Class II Div1Class II Div 2Class II Div 2Class IIIClass IIISkeletal Skeletal DentalDental

TRANS-TRANS-SAGITTALSAGITTAL

SAGITO-SAGITO-VERTICALVERTICAL

VERTICO-VERTICO-TRANSVERSETRANSVERSE

TRANS-TRANS-SAGITO-SAGITO-

VERTICALVERTICAL



Classification by groupsClassification by groupsCommon to all dentitions is the degree of alignment and Common to all dentitions is the degree of alignment and

symmetry of the teeth within the dental arches. This is symmetry of the teeth within the dental arches. This is represented as the universe represented as the universe (Group 1).(Group 1).

Many malocclusions affect the profile. For this reason, Many malocclusions affect the profile. For this reason, profile is represented as a major set profile is represented as a major set (Group 2)(Group 2) within the within the universe. universe.

Lateral (transverse), anteroposterior (sagittal), and Lateral (transverse), anteroposterior (sagittal), and vertical deviations and their interrelationships vertical deviations and their interrelationships (Groups 3 to 9)(Groups 3 to 9) are represented by three interlocking subsets within the profile are represented by three interlocking subsets within the profile set. set.



Step 1 Step 1 in the classification procedure is an analysis of the in the classification procedure is an analysis of the alignment and symmetry of the teeth in the dental arches alignment and symmetry of the teeth in the dental arches (interproximal contact relationships). (interproximal contact relationships).

Alignment is the key word of Group 1; among the Alignment is the key word of Group 1; among the possibilities are possibilities are idealideal, , crowding (arch-length deficiencycrowding (arch-length deficiency), ), spacingspacing, and , and mutilatedmutilated. Irregularities of individual teeth . Irregularities of individual teeth are described, if desired, by the method of Lischer, namely, are described, if desired, by the method of Lischer, namely, the use of the suffix -version to describe the direction of the use of the suffix -version to describe the direction of individual tooth malalignments. individual tooth malalignments.

Ideal occlusion, plus many (but by no means all) Angle Ideal occlusion, plus many (but by no means all) Angle Class I malocclusions, would fall into Group 1.Class I malocclusions, would fall into Group 1.



In In Step 2Step 2 one views the patient's profile. one views the patient's profile.

In the profile view, it should be noted whether the face is In the profile view, it should be noted whether the face is anteriorly divergentanteriorly divergent (mandible prominent) or (mandible prominent) or posteriorly posteriorly divergentdivergent (mandible recessive) and whether the lips are (mandible recessive) and whether the lips are convex convex (prominent), (prominent), straightstraight, or , or concaveconcave relative to the relative to the nose and chin. The "divergence" is most often related to the nose and chin. The "divergence" is most often related to the facial skeleton; lip position is strongly influenced by the facial skeleton; lip position is strongly influenced by the teeth. Lip and mouth posture should also be considered in teeth. Lip and mouth posture should also be considered in the evaluation.the evaluation.



In In Step 3Step 3 the dental arches are viewed with regard to lateral the dental arches are viewed with regard to lateral dimensions (transverse plane), and the buccolingual dimensions (transverse plane), and the buccolingual relationships of the posterior teeth are noted. relationships of the posterior teeth are noted.

The term type is used to describe the various kinds of cross-The term type is used to describe the various kinds of cross-bite. A judgment is also made as to whether the problem is bite. A judgment is also made as to whether the problem is basically dentoalveolar or skeletal or due to a combination basically dentoalveolar or skeletal or due to a combination of the two.of the two.

Buccal and palatal cross bites ( unilateral or bilateral) Buccal and palatal cross bites ( unilateral or bilateral) comes under this categorycomes under this category



In In Step 4Step 4 the patient and dental arches are viewed in the the patient and dental arches are viewed in the anteroposterior dimension (sagittal plane). anteroposterior dimension (sagittal plane).

In this dimension, the Angle classification system is utilized In this dimension, the Angle classification system is utilized and is merely supplemented by stating whether a deviation and is merely supplemented by stating whether a deviation is skeletal, dentoalveolar, or a combination. This is skeletal, dentoalveolar, or a combination. This information can be derived from observing the patient or information can be derived from observing the patient or more accurately from a cephalometric head film.more accurately from a cephalometric head film.



In In Step 5Step 5 the patient and the dentition are viewed with regard to the patient and the dentition are viewed with regard to the vertical dimension. the vertical dimension.

Bite depth is used to describe the vertical relationships. The Bite depth is used to describe the vertical relationships. The possibilities are possibilities are anterior open-bite, anterior deep-bite, anterior open-bite, anterior deep-bite, posterior open-bite, or posterior collapsed biteposterior open-bite, or posterior collapsed bite. To . To determine whether this is on a determine whether this is on a skeletal,skeletal, dentoalveolardentoalveolar, or , or combinedcombined basis, a cephalometric analysis may be basis, a cephalometric analysis may be particularly helpful.particularly helpful.



This approach defines nine groups of malocclusions. This approach defines nine groups of malocclusions. The complexity of the orthodontic problem increases with the The complexity of the orthodontic problem increases with the group number. Thus, a Group 9 malocclusion is the most group number. Thus, a Group 9 malocclusion is the most complex in that there is an alignment problem, a problem in complex in that there is an alignment problem, a problem in profile, and problems in the lateral, vertical, and anteroposterior profile, and problems in the lateral, vertical, and anteroposterior dimensions as well. dimensions as well.



Advantages of this classificationAdvantages of this classification This method of classification based on five descriptive characteristics This method of classification based on five descriptive characteristics

and defining nine groups of malocclusions overcomes the major and defining nine groups of malocclusions overcomes the major weaknesses of the Angle systemweaknesses of the Angle system

Specifically, arch-length problems, with or without an influence on the Specifically, arch-length problems, with or without an influence on the profile, are recognized; the influence of the dentition on the profile is profile, are recognized; the influence of the dentition on the profile is taken into accounttaken into account

All three planes of space, not just the sagittal plane, are taken into All three planes of space, not just the sagittal plane, are taken into considerationconsideration

The differentiation between dental and skeletal problems is made at the The differentiation between dental and skeletal problems is made at the appropriate levelappropriate level

Diagnosis is inherent in the classificationDiagnosis is inherent in the classification


ETIOLOGIC ETIOLOGIC CLASSIFICATIOCLASSIFICATIONN

According to Moyers, Classification of According to Moyers, Classification of malocclusion can be based on the origin of the malocclusion can be based on the origin of the problem. There are four classes depending on originproblem. There are four classes depending on origin

Skeletal or OsseousSkeletal or Osseous

Dental Dental

MuscularMuscular

Combination of aboveCombination of above


CONCLUSIONCONCLUSIONThe goal of modern orthodontics can be summed The goal of modern orthodontics can be summed up as the creation of the best possible occlusal up as the creation of the best possible occlusal relationships within the framework of acceptable relationships within the framework of acceptable facial aesthetics and stability of the occlusal facial aesthetics and stability of the occlusal result. The classification systems aid in diagnosis result. The classification systems aid in diagnosis and treatment planning of malocclusions. There is and treatment planning of malocclusions. There is a basic need for a system of classification of a basic need for a system of classification of malocclusion that would be adequate for clinical, malocclusion that would be adequate for clinical, semantic and public health purpose and could be semantic and public health purpose and could be universally employed by those practicing the universally employed by those practicing the specialty throughout the worldspecialty throughout the world


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