Dentition patterns in bilateral cleft lip subphenotypes: multicenter study

Here, we retrospectively investigated cases of bilateral oral clefts (OCs) to determine the clinical relevance of detailed distinction of incomplete cleft lip subphenotypes, based on morphological severity of the cleft, within the categories cleft lip with or without alveolus (CL ± A) and cleft lip, alveolus, and palate (CLAP). We further assessed possible associations between CL subphenotypes (complete vs different incomplete types) and different dentition patterns of the lateral incisor.

Our analysis included 151 non-syndromic Caucasian bilateral OC-patients (8-20 years old) from the Dutch Association for Cleft Palate and Craniofacial Anomalies registry. Six different deciduous and permanent lateral incisor patterns were distinguished: normal position (z/Z), supernumerary lateral incisor (n/N), presence in the anterior (x/X) or posterior (y/Y) segment of the cleft, one in each cleft segment (xy/XY), and agenesis (ab/AB). Logistic regression was performed to show the associations between the CL subphenotypes and dentition patterns of the lateral incisor.

One hundred three had complete, while 48 had incomplete CLs. Patterns z/Z and n/N were associated with a submucous/vermillion notch, incomplete CL, and intact alveolus. Patterns x/X, y/Y, and xy/XY were most common in patients with two-thirds to subtotal CL and complete CL. The most severe pattern, ab/AB, was most commonly associated with complete CL.

Based on the morphological severity of the CLs, it can be stated that the more severe the CL in bilateral CL ± A and CLAP, the more severe the abnormal pattern of the dentition.

Further distinction of incomplete cleft lip subphenotypes (submucous/vermillion notch, one-third to two-thirds CL, two-thirds to subtotal CL) in bilateral CL ± A and CLAP has clinical relevance.