Observations on the Mandible in Association with Defects of the Lip and Palate

¹ Departments of Anatomy and Pediatrics, College of Medicine, University of Cincinnati, and Children's Hospital Research Foundation, Cincinnati, Ohio

Children with cleft lip and palate had retrognathia when compared with children with fairly good occlusion and well-developed facial characteristics. Mice with spontaneous cleft lip and palate, however, had mandibles of normal length. This difference between children and mice is of interest in view of the otherwise great similarity—in sex distribution, laterality, morphology, and genetics—between these defects in mice and man.

Cortisone-induced cleft palate, on the other hand, in distinction to both cleft palate with micrognathia and cleft palate with an apparently normal mandible, was found to be accompanied by a mandible of relatively greater than normal length. This increase was due solely to a relative increase in length of the premolar mandibular corpus.