Tooth agenesis code (TAC) in complete unilateral and bilateral cleft lip and palate patients

The objective of this study is to characterize and compare tooth agenesis codes and their prevalence in a population of Spanish patients with unilateral cleft lip and palate (UCLP) and bilateral cleft lip and palate (BCLP), and to determine if the extent of the cleft (BCLP or UCLP) was associated with the number of absent teeth. This retrospective cross-sectional human study included 118 patients with complete BCLP (29) or UCLP (89) and permanent dentition from first molar to first molar. Congenitally missing teeth were identified on panoramic radiographs using the tooth agenesis code (TAC) to identify agenesis codes. Agenesis prevalence was 50.6 and 51.7% for UCLP and BCLP patients, respectively. The lateral upper incisor was the most frequently absent tooth, especially in the cleft quadrant. Numbers of absent teeth ranged from 1 to 6. This study represents a different approach from previous agenesis investigations in cleft patients. These Spanish patients showed a high number of ageneses, presenting nineteen different tooth agenesis codes. A total of five TACs were unique, in other words, observed in a single patient in the sample. No statistically significant relationship was found between the extent of the cleft and the number of absent teeth. The TAC system makes it possible to identify agenesis codes with simultaneous absence of teeth not detected in general prevalence studies.