Orthodontic management of a non-syndromic patient with concomitant bimaxillary hypohyperdontia: a case report

Tooth agenesis is one of the most common dental anomalies; however, the concomitant occurrence of opposite dental numerical variation of hypohyperdontia is extremely rare.

To report the successful orthodontic management of a patient with non-syndromic concomitant bilateral agenesis of mandibular canines and two midline inverted supernumerary maxillary teeth.

21-year-old female patient with a chief complaint of protrusive right maxillary central incisor. The patient was diagnosed with a mild Class II skeletal base, Angle Class III molar relationship and increased overjet associated with hypohyperdontia. Anterior open bite accompanied with tongue-thrusting habit were also observed. Two temporary anchorage devices (TADs) were implanted at the buccal side of the maxillary molar region to control vertical height. Anterior teeth retraction was done after extraction of the maxillary first premolars, to improve the excessive overjet. The treatment mechanics involved lingual brackets system for the maxillary arch and transpalatal arch for anchorage control.

The total active treatment period was 35 months. Acceptable occlusion with increased bite force and contact area as well as functional excursion were established without interference, following complex orthodontic treatment with premolar substitution. The resultant occlusion and a satisfactory facial profile were maintained after 29 months of retention.

The present case report provides implications regarding the orthodontic treatment of hypohyperdontia-associated substitution for missing teeth as an effective option for improving aesthetic and functional aspects.