Agenesis of the second premolar in males and females: distribution, number and sites affected.

One of the most common anomalies of the dentition is congenitally absent second premolars and this form of hypodontia may occur as an isolated trait or in association with a syndrome. Using radiographs and clinical examinations, hypodontia of second premolars was assessed in 176 subjects (80 male and 96 female). Distribution of the hypodontia was assessed according to site and number missing in males and females. No significant differences were observed in males and females with respect to the number of premolars absent, sites affected or symmetry of the agenesis. Agenesis of a single second premolar was the most common form of this hypodontia with absence of three second premolars occurring least frequently.