Classification Of Malocclusion Question And Answers

Classification Of Malocclusion

Question 1. Define malocclusion. Describe the Angle’s classification of malocclusion. 
Or
Write Angle’s classification of malocclusion.
Or
Write a short note on Angle’s classification.
Answer. Malocclusion is a condition in which there is a departure from the normal relation of the teeth to other teeth in the same arch and/or to teeth in the opposing arch. Gardiner, White, and Leighton

Angle’s Classification of Malocclusion

Edward Angle introduced a system of malocclusion in 1899.

• Angle’s classification was based on the mesiodistal relation of the teeth, dental arches and the jaws.
• According to Angle the maxillary first permanent molar is the key of occlusion.
• Based on the relation of the lower 1st permanent molar to the upper 1st permanent molar, Angle classified malocclusion into 3 main classes:

Angle’s Class 1 Malocclusion (Neutrocclusion)

Molar relation: Mesiobuccal cusp of maxillary fist permanent molar occludes in the mesiobuccal groove of mandibular fist permanent molar.

Canine relation: Mesial inclination of maxillary canine occludes with distal inclination of mandibular canine whereas distal inclination of maxillary canine occludes with mesial inclination of mandibular fist premolar.

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Line of occlusion: It get alter in maxillary and mandibular arches.

• Tooth irregularities like crowding, spacing, missing of tooth and rotations are seen.
• Interarch problems such as deep bite, increased overjet, cross bite and open bite are seen.

Class 1 Bimaxillary Protrusion

It is a condition in which key of occlusion and line of occlusion are not altered, but maxillary and mandibular anteriors are proclined and exist in edge-to-edge relationship.

Angle’s Class 2 Division 1 Malocclusion (Distocclusion)

Molar relation: This group is characterized by class II molar relation where the distobuccal cusp of permanent maxillary fist molar occludes in the buccal groove of the permanent mandibular fist molar.

Class 2 canine relation: Distal incline of maxillary canine occludes with mesial inclines of mandibular canine.

Line of occlusion: It will get altered. Various other features of class 2 division 1 malocclusion are:

• Proclined maxillary incisors.
• Deep bite.
• Lip trap.
• V-shaped maxilla.
• Exaggerated curve of Spee.

Class 2 division 1 subdivision: In this there is unilateral class 2 molar relationship with normal class 1 molar occlusion over other side.

Angle’s Class 2 Division 2 Malocclusion

Class 2 molar relation: Mandibular arch is distally positioned in relation to maxillary arch. Distobuccal cusp of maxillary fist molar occludes with mesiobuccal groove of mandibular fist molar.

Class 2 canine relation: Distal incline of maxillary canine occludes with the mesial incline of mandibular canine.

Line of occlusion: It becomes altered.

• Other Features: Arch become square shaped.
• Curve of Spee is exaggerated.
• Close bite.
• Lingual inclination of maxillary central incisor or lingual inclination of both maxillary central and lateral incisors.
• Retroclined incisors overlapped by canine.

Class 2 division 2 subdivision: Class II molar relation occur on one side with normal molar relation on other side.

Angle’s Class 3 Malocclusion (Mesiocclusion)

Class 3 molar relation: Mesiobuccal cusp of maxillary fist permanent molar occlude with interdental space between mandibular fist and second permanent molars.

Class 3 canine relation: Maxillary canine occludes with interdental space between mandibular first and second premolars.

Line of occlusion: It can or cannot be developed.

Other Features:

• Anterior crossbite
• Posterior crossbite
• Maxillary anterior crowding.

Class 3 subdivision: In this class III molar relation is present over one side with normal molar relation to other side.

True Class 3:

It is a skeletal malocclusion.

Causes are prognathic mandible, retrognathic maxilla, combination of both.

Pseudo Class 3:

• It occurs because of occlusal prematurities, when the mandible moves from rest to occlusion, it slide forward into pseudo class III malocclusion.
• In rest position patient show normal molar relationship.