Palatomandibular and maxillo-mandibular fusion, partial aglossia and cleft palate in a human embryo. Report of a case.

A 32-mm CRL male human embryo was examined for malformation. Histological observation showed fusion between the left vertical palatal shelf and mandible and the maxilla and mandible in the posterior part of the oronasal cavity. The right shelf was horizontal anteriorly, vertical posteriorly and changing its position from a vertical to a horizontal plane in the middle. The tongue was underdeveloped anteriorly and completely absent posteriorly. The mandibular tooth buds were not formed. Both clinical and experimental literature were analyzed to find the mechanism of statu nascendi defect observed in the present case. It was deduced that the tongue may not play an active role during normal palatal development and that it may not have played any role during the fusion between different intraoral structures observed in the present case. It was concluded that, had the embryo developed further, then at the birth a cleft palate, partial aglossia and associated intraoral malformation would have been expected.