Class II and Class III Malocclusions Explained

Biology20 May 20263.12 KB

Class II Malocclusion

Features: Distal position of the inferior teeth relative to the superior teeth.
Etiology: Mesial migration of superior incisors, caries, or premature loss of deciduous teeth.

Characteristics: Inadequate development or jaw position.
Etiology: Basic bone dysplasia of the maxilla and mandible, genetic factors, environmental factors, trauma, and temporomandibular joint (TMJ) pathology.

Facial features: Convex profile, lip incompetence, chin hypertonicity in open bite, superior procheilia, and inverted lower lip.
Skeletal features: Hypergonian, open mandibular plane, open bite, and increased facial height.
Dental characteristics: Vestibuloversion of superior incisors and extrusion with diastema, linguoversion of inferior incisors with crowding, anterior open bite, increased overjet, and a pronounced Curve of Spee.

Facial features: Convex or straight profile, diminished facial height, brachycephalic, pronounced labiomental groove, and superior retrocheilia.
Skeletal features: Deep bite and decreased facial height.
Dental characteristics: Distal molar and canine relationship, palatally inclined superior central incisors, lingualized inferior incisors, vestibuloversion of canines, deep bite, increased overbite, and in some cases, anterior-inferior crowding.

Skeletal defect in the intermaxillary relationship, characterized by maxillary or mandibular bone dysplasias.

Characteristics: Mesial molar and canine relationship, anterior crossbite, anterior deep bite, and negative overjet.
Etiology: Eruptive disorders, tooth size discrepancies, residual growth, and pseudo-prematurities (pseudo-Class III due to anterior mandibular displacement or breathing difficulties).

Characteristics: Mandibular protrusion, maxillary retrusion, or a combination of both.
Etiology: Genetics (bone dysplasia linked to race).

Version (Inclination): Teeth are inclined around their horizontal axis. Types include labioversion, lingualversion, mesioversion, and distoversion.
Gression (Position): The tooth is not in its correct position in the dental arch. Types include labiogression, linguogression, mesiogression, distogression, egression (extrusion), and ingression (intrusion).
Rotations: Rotation of the tooth around its long axis without displacement. Types include distobuccal, distopalatal, mesiobuccal, or mesiopalatal rotation.
Transposition: Positional exchange between two adjacent teeth in the dental arch.