5. Classification of malocclusion .pdf

BASIC CLASSIFICATION OF MALOCCLUSION DR SNIGDHA PATTANAIK Learning outcomes Classify the molars relationship according to Angle State the drawbacks of Angle’s Classification Classify the incisors relationship according to “The British Standards Institute’s classification of the incisors relati...

BASIC CLASSIFICATION OF MALOCCLUSION DR SNIGDHA PATTANAIK Learning outcomes Classify the molars relationship according to Angle State the drawbacks of Angle’s Classification Classify the incisors relationship according to “The British Standards Institute’s classification of the incisors relationship” Classify the Canines relationship State the degree of discrepancies in the molars, incisors and canines relataoships Overview talksabt y •The Angle classification of malocclusion •Principles of Angle’s classification molarst •Types (I, II/I, II/II, III) •Drawbacks of Angle’s Classification talksabt y I •The British Standards Institute’s classification of incisor relationship •I •II (division I and division II) •III I •I •Canine relationship •II •III The Angle classification of malocclusion •Introduced by Edward H Angle in 1899. •Commonly used classification. Principles of Angle’s classification QWhats the classifi •Maxillary first permanent molar- “key to occlusion.” mangle's •Relationship of first molars. •Anteroposterior relationship of dental arches. I b b The Angle classification of malocclusion CLASS I  Mesiobuccal cusp of the maxillary first permanent molar lies in the buccal groove of the mandibular first permanent molar. This is considered to be the normal relationship. MBcusp 119 I BuccalGroove The Angle classification of malocclusion CLASS II DIVISION 1 chin retruded 1. The mesiobuccal cusp of the maxillary first permanent molar occludes anterior to the buccal grove of the mandibular first molar. Is 2. The distobuccal cusp of the maxillary first permanent molar occludes with the buccal grove of the mandibular first permanent molar. 3. The maxillary central incisors are proclined. 4. The overjet is increased. causes All 4 incisors are proclined causes - increase overjet The Angle classification of malocclusion CLASS II DIVISION 2 1. The mesiobuccal cusp of the maxillary first permanent molar occludes anterior to the buccal grove of the mandibular first molar. 2. The distobuccal cusp of the maxillary first permanent molar occludes with the buccal grove of the mandibular first permanent molar. 3. The maxillary central incisors are retroclined. lateralsareproclined 4. The overjet is typically reduced. Central incisors are retroclined BUT lateral incurs are proclined= causes deep bite and reduced overjet The Angle classification of malocclusion Class II—Subdivision: When the Class II molar relationship occurs on one side of the dental arch only, the malocclusion is referred to as a subdivision of its division. • Q. If there’s different molar relation ( class 1 molar relation on right side AND class 2 molar relation on left side) on different sides of the arch, what will you write? I will consider it as class 2 subdivision • In class 2 theres only one type of subdivision ◦Class 1 on one side and class 2 on the other side of the arch, we write class 2 subdivision ( since theres only one subdivision) The Angle classification of malocclusion CLASS III • In class 3 the mandibule is very protruded The MB cusp of upper rst molar is between the lower rst and second molar • Imicro relation is crossbite The mesiobuccal cusp of the maxillary first permanent molar occludes posterior to the buccal grove of the mandibular first permanent molar. The Angle classification of malocclusion Class III—Subdivision When the Class III molar relationship occurs on one side of the dental arch only, the malocclusion is referred to as a subdivision of its division. • In class 3 theres 2 types of subdivisions: ◦ Class 3 on one side and class 1 on one side you will write class 3 subdivision 1 ◦Class 3 on one side and class 2 on side, you will write class 3 subdivision 2 What Are The Drawbacks of Angle’s Classification The first permanent molars are not fixed in the dental arches e.g. can be extracted or mal-positioned Is classitonlyappliedon It is meant to be applied in the permanent dentition It assesses the occlusion in the A-P plane only Individual teeth are not considered in the classifications Dental classification only (no skeletal component in the classification) The severity of malocclusion is not accurately assessed For the British’s classi cation theory consider the ◦Cingulum of upper ◦Incisal edge of lower The British Standards Institute’s classification of incisor relationship CLASS I The lower incisor edges occlude on or lie just below the cingulum plateau of the upper incisors. Brief: • if lower is forward which is related to class 3 relation = indicates open bite or reversed overjet • If lower is backward ( more to gingiva)which is related to class 2 = indicates deep bite ◦You can see teh incisal edge is contacting the cingulm of upper The British Standards Institute’s classification of incisor relationship CLASS II, DIVISION 1 the upper arepwained The lower incisor edges occlude behind the cingulum plateau of the upper incisors and the upper incisors are proclined or normally inclined. • When teh incosal edge of the lower is toward the gingiva overjet is increased means this is class 2 division. • When there’s reduced overjet this means this is class 2 division 2 The British Standards Institute’s classification of incisor relationship CLASS II, DIVISION 2 lined When Ci ane retroc The lower incisor edges occlude behind the cingulum plateau of the upper incisors and the upper incisors are retroclined. The British Standards Institute’s classification of incisor relationship CLASS III The lower incisor edges occlude anterior to the cingulum plateau of the upper incisors. Canine relationship CLASS I The tip of the maxillary permanent canine occludes in the embrasure space between the lower canine and first premolar Kita Canine relationship CLASS II The tip of the maxillary canine occludes anterior to the embrasure space between the lower canine and first premolar. i • If theres more than 2 mm gap from class 1 ( tip of k9 at embrasure ) and distance is away 2mm away from embrasure - class 2 I pin kg p Canine relationship CLASS III The tip of the maxillary canine occludes posterior to the embrasure space between the lower permanent canine and first premolar. • This is a severe case of class 3 ◦Upper k9 is at least 2 or more behind the class 1 relation Q. What is considered to be class 3? Mild class Edge to severe class 3 edge and also reversed over- jet