332 THE EAR commonly present but are relieved by successful antibiotic treatment. Increasing pain or the return of pain and increasing mastoid tenderness are therefore significant. Tenderness occurs not only over the mastoid antrum (Macewen's triangle) but may be elicited on pressure over the mastoid tip and posterior border. In an untreated case of mastoiditis discharge from the ear will usually have increased with extension of the disease but in a 'masked* case discharge may be absent and the perforation may have healed. A B Fig. 170. Mastoid radiographs. A, Cellular; B, Sclerotic. Fig. 171. Acute mastoiditis. A, Anterior and B, posterior views showing the swelling produced by a subperiosteal abscess.