[Extraoral odontogenic fistulas: a classification and a differential diagnosis from other type head and neck fistulas].

The majority of extraoral facial fistulas are of odontogenic origin. Although the differential diagnosis of draining lesions should include various types of skin infection, infected tumour, specific infections, failed wound healing, foreign body, salivary gland fistula, sebaceous cysts and developmental cysts and fistulas. This report documents a group of patients with extraoral draining skin lesions and illustrates that their diagnosis is very important because clinically they can resemble many pathologic entities. One hundred and twenty-eight cases of extraoral fistulas are presented in this paper. This study aims to analyse a number of fistula cases so as to give a clear idea about relative frequency of etiology and to attract to some cases of non odontogenic etiology.