Dental anomaly pattern (DAP): agenesis of mandibular second premolar, distal angulation of its antimere and delayed tooth formation.

Objective: To test the null hypotheses that children with unilateral agenesis of the mandibular second premolar (MnP2) do not show (1) greater distal angulation of the unerupted antimere and (2) delayed tooth formation compared with children without agenesis.

Materials And Methods: Panoramic radiographs of 38 patients with unilateral aplasia of MnP2 were retrospectively examined and compared to a non-agenesic control group of 82 patients. Ages ranged from 8 to 15 years.