A syndrome of hemimaxillary enlargement, asymmetry of the face, tooth abnormalities, and skin findings (HATS).

Hemimaxillofacial dysplasia and segmental odontomaxillary dysplasia appear to be the same syndrome, having the common features of unilateral abnormalities of bone, teeth, gums, and skin. Oral manifestations are the hallmark of this condition. Those affected are generally recognized in childhood and may have partial anodontia, abnormal spacing of the teeth, delayed eruption, and gingival thickening of the affected segment. Reported cutaneous manifestations include facial asymmetry, Becker's nevus, "hairy nevus," lip hypopigmentation, discontinuity of the vermilion border, depression of the cheek, and erythema. The oral lesions do not appear to be progressive. We describe a child with features consistent with hemimaxillofacial dysplasia/segmental odontomaxillary dysplasia. Findings of a biopsy specimen from the cheek confirmed the presence of a Becker's nevus. Cutaneous findings reported in the previous 31 cases are reviewed and summarized. The acronym HATS (hemimaxillary enlargement, asymmetry of the face, tooth abnormalities, and skin findings) is introduced to reflect the spectrum of abnormalities in bone, teeth, and skin that may be seen in this developmental disorder.