Median facial dysgenesis in cleft lip and palate.

Eight patients, aged 9 months to 9 years, each with unusual complete cleft of the primary and secondary palate on one side and a complete cleft of the secondary palate on the opposite side, were evaluated. All showed varying deficiencies of median facial mesodermal dysgenesis characterized by absent frenulum, indefinite cupid's bow, deficient septal cartilage and nasal spine, and absent central and lateral incisor of the cleft side of the premaxilla. Computerized tomographic scan confirmed the absence of the central nervous system anomalies seen in midline clefts. Cephalometric studies revealed maxillary hypoplasia and no evident hypotelorism. These patients demonstrate a definable lack of median mesodermal penetration along with failure of lateral mesodermal penetration. It is to be noted that median facial dysgenesis can occur without recognizable central nervous system disorders. It is quite possible that microforms of median facial dysgenesis occur in unilateral and bilateral cleft lip and palate patients. This would help explain the wide variations of clefting seen clinically.