Longitudinal changes in the dento-facial relationships of unilateral cleft lip and palate subjects

Nine male and nine female subjects with surgically repaired unilateral cleft lip and palate were compared to 20 male and 15 female noncleft individuals. Different cephalometric landmarks were identified, and eighteen different measurements or calculations were used to describe the mandible, maxillary-mandibular complex, and dental relationships. Univariate longitudinal facial growth profiles and mean vector analyses as well as multivariate comparisons were performed between male, female, and combined non-cleft and cleft groups. Linear data comparisons indicated statistically significant differences in the growth profile of those measurements describing the changes in the relationship of the lower border of the mandible (MP:SN angle) and the y-axis to the anterior cranial base (NSGn). The maxillary-mandibular relationship (angles ANB and NAPog) and dimensions (Ans-PTm/Pog) exhibited statistically significant differences in the growth profiles of the non-cleft and cleft groups. Such differences were also found in the relationship of the lower incisors to the mandibular plane (1:MP angle). The mean vector analysis for the dental measurements pointed to significant differences for all comparisons made, particularly in the combined non-cleft groups. These measurements were of larger magnitude in the non-cleft group than in the cleft group except for the interincisal angle (1:1), which was larger in clefts.