Cutaneous fistula on the cheek associated with oculo-auriculo-vertebral spectrum

A Japanese boy, presented with epibulbar dermoid and ipsilateral preauricular appendages, had a pit on his cheek of the same side. An atrial septal defect and vertebral fusions were also identified. He was diagnosed with a mild type of oculo-auriculo-vertebral spectrum (OAVS). At the age of 18 months, his cheek was swollen with a slight fever. An infected cyst and cutaneous fistula enveloped by the risorius muscle were extracted. It was assumed to be a remnant of the fissure between the maxillary and mandibular prominences. This was the first case of cutaneous fistula confirmed histologically with OAVS, although there seem to be more cases. The possibility of the mechanism of smiling cheek dimple is also discussed.