Class 3 malocclusion is a dental condition in which the lower teeth and jaw protrude farther forward than the upper teeth and jaw. This abnormal relationship gives the face a concave appearance in profile, with a prominent chin. Class 3 malocclusion is the rarest type of dental misalignment, with an estimated prevalence of 1-5% in white populations. Class 3 malocclusions are considered to be one of the most difficult orthodontic problems to treat.
In two-thirds of cases, it is caused by maxillary retrognathism or a combination of maxillary retrognathism and mandibular prognatism. To correct this malocclusion when it is skeletal, orthodontics combined with orthognathic surgery is the recommended treatment. The postorthodontic occlusion should have a class III molar and premolar ratio, a class I canine relationship, and normal overbite and overbite of the incisors. The main objectives of treatment are to correct the class III canine relationship, overjet and overbite, and improve facial aesthetics.
Treatment plans may include extractions of the second upper and lower molars to gain space, correct upper crowding, achieve a class I molar ratio, and provide good vertical and horizontal control of the teeth during orthodontic biomechanics. The choice between orthodontic camouflage and orthognathic surgery is one of the most controversial issues in treating patients with class III malocclusion. Orthodontic camouflage is recommended for patients with slight anteroposterior skeletal discrepancy and functional discrepancy of the CO-CR, as well as low-angle cases. Class II occlusion occurs when the lower dental arch is posterior (more toward the back of the mouth) than the upper one.
This type of misalignment can be corrected with orthosurgical correction combined with first premolar extractions without follow-up orthodontic treatment. In conclusion, class 3 malocclusion is a complex dental condition that requires careful diagnosis and treatment planning. Orthodontics combined with orthognathic surgery is usually recommended for skeletal malocclusions, while orthodontic camouflage may be suitable for mild cases.
