Non-syndromic tooth agenesis patterns and their association with other dental anomalies: A retrospective study.

OBJECTIVE: This study aimed to investigate the prevalence and the factors associated with non-syndromic tooth agenesis, besides identifying its pattern of occurrence.

STUDY DESIGN: Pre-orthodontic exams of 3400 subjects, aged 8-30 years, were selected from a radiographic center in Brazil. Panoramic and periapical radiographs were analyzed to verify the presence of tooth agenesis and other six dental anomalies. Descriptive statistics were calculated using the Tooth Agenesis Code tool and, to evaluate significant associations, a negative binomial regression model was constructed. Besides, unadjusted and adjusted prevalence ratios (PR) were calculated for the bivariate and the multivariate analysis.

RESULTS: Prevalence of tooth agenesis was 3.0% (n = 68) and 41 different phenotypic patterns were observed. Teeth most often symmetrically missing were maxillary lateral incisors (13.2%) and mandibular second premolars (8.8%). Females (PR = 3.49, CI 95% = 1.96-6.19) presented more tooth agenesis. Other dental anomalies, such as palatal displacement of maxillary canine and infraocclusion of primary molar were significantly more frequent (p < 0.001) in subjects with agenesis.

CONCLUSION: There was a strong relationship between tooth agenesis and gender and the association with other dental anomalies was significant, with the exception of the supernumerary teeth, which seems to be independent.