Cleft lip and palate are associated with a higher prevalence of molar-incisor hypomineralisation: a cross-sectional study with a comparison group.

Purpose: To assess the association between non-syndromic cleft lip and/or palate (NSCL/P) and developmental defects of enamel (DDE), including the DDE subtypes, such as molar-incisor hypomineralisation (MIH) and hypomineralised second primary molars (HSPM).

Methods: This cross-sectional study with a comparison group included individuals with and without NSCL/P ("NSCL/P group" and "control group," respectively). The NSCL/P group was recruited from a specialised craniofacial centre, and the control group was randomly selected from a population-based sample of schoolchildren, in a 1:2 ratio. DDEs were assessed by calibrated examiners through clinical examination. Associations between NSCL/P and DDE were analysed using univariate Poisson regression with robust variance (α = 5%), and comparisons between subtypes included Bonferroni-adjusted p values to account for multiple testing.

Results: The sample included 164 children with NSCL/P and 328 controls (mean age = 8.09 ± 1.39 years). DDEs were more prevalent in the NSCL/P group (76.8%) than in controls (66.2%) (p < 0.01). Hypoplasia, demarcated opacities, and MIH/HSPM were significantly more frequent in the NSCL/P group (p < 0.01). Fluorosis was significantly more prevalent in the control group (p < 0.01). MIH was the most frequent DDE in the NSCL/P group (29.3%). DDEs in the anterior teeth were significantly associated with cleft laterality, being most frequent in bilateral clefts (p < 0.01).

Conclusion: Children with NSCL/P have a higher prevalence of DDE than those without clefts. MIH was the most prevalent defect observed in this population, highlighting its clinical relevance.