abnormal dentition in a boy with incontinentia pigmenti: case report.

incontinentia pigmenti (ip) is an x-linked dominant genodermatosis characterized by typical skin lesions along blaschko's lines and associated with ocular, dental, nails, hair, skeletal, central nervous system and cardiovascular anomalies. we report a 5-year-old boy with cutaneous hyperpigmentation along blaschko's lines, atrophic streaks, strabismus and mental retardation. he showed the characteristic abnormal dentition seen in ip as partial hypodontia, peg-shaped anterior teeth and un-erupted teeth. the expression of ip in boys is exceptional as the disease is lethal in males.