Prevalence of Mandibular Tooth Agenesis in a Nonsyndromic Cleft Population: A Case-Control Study.

ObjectiveGain insight into the prevalence of mandibular tooth agenesis (MA) in a cleft population in comparison to MA in a non-cleft population.DesignRetrospective single-center cohort study with panoramic radiographs analysis.SettingFrisius Medical Center Leeuwarden, The Netherlands.ParticipantsThe study group had 232 individuals with a nonsyndromic cleft lip (CL), cleft lip and palate (CLP) or cleft palate (CP) on treatment by Cleft Team North. The Control group had 350 individuals without an orofacial cleft from the Department of Oral and Maxillofacial Surgery.Main Outcome MeasuresMA per individual and per element type, using the Tooth Agenesis Code.Results10.3% of the cleft group and 4.9% of the control group had MA (P = .013). MA was 4 times more prevalent in CP (16.4%) and tended to be 2 times more prevalent in CLP (9.4%) compared to the control group (P = .005 and P = .063, resp.). CL had no MA. The mandibular second premolar (P2) was the most often affected element in both cleft and control groups. Compared to the control group, the left P2 was more often agenetic in CLP and CP (P = .010 and P = .003, resp.) and the right P2 only in CP (P = .014). Unilateral and bilateral CLP had corresponding locations of agenesis.ConclusionsTooth agenesis in the mandible seems part of the phenotype of CLP and CP. This suggests common underlying pathways to both orofacial clefts and MA.