In one study, the number of new cases of<unk>  in Iowa was estimated in 1975–6 to be just under one new case per 10,000 citizens per year.<unk>  affects all age groups, from infants through to the elderly. The peak incidence occurs in the second decade.
Cholesteatoma
Orbital cellulitis
Orbital lymphoma
Odontogenic keratocyst
Tympanosclerosis
Pseudolymphoma
Periorbital cellulitis
Rectovestibular fistula