Investigation of voice disorders in public school teachers hospitalized for complete physical examination

Abstract

In order to investigate voice disorders among school teachers, we studied public school teachers who underwent thorough medical examinations during the last three years at hospitals managed directly by the Japan Mutual Aid Association of Public School Teachers. The total number of subjects was 11,413. A questionnaire presented to the subjects showed that 8.5 percent of all teachers complained of hoarseness. Among these, 180 cases were examined at our ENT clinic and subsequently diagnosed as true voice disorders. Diagnoses consisted of vocal cord nodules (46%), muscle tension dysphonia (20%), chronic laryngitis (11%), vocal polyps (4.4%) and other vocal cord abnormalities. Analysis of the first two categories revealed apparent gender dominance. Most cases of vocal cord nodules were female, while muscle tension dysphonia showed male domination. As with the subject group as a whole, both case categories reached peak at the age of 50-59. Male teachers with vocal cord nodules were mostly habitual smokers, suggesting a relation between smoking and formation of lesions in male teachers. These results provide data beneficial not only for treatment but also for prevention of voice disorders in school teachers.