Importance of glottic configuration in the development of posterior laryngeal granuloma.

Posterior laryngeal granuloma is frequently related to 3 predisposing factors: vocal abuse, gastroesophageal reflux disease, and orotracheal intubation. It is strongly predominant in men and rare in women, except under postintubation circumstances, in which the incidence is higher in women. The aim of this study was to characterize laryngeal conformations for each sex that, whenever associated with different causes, may lead to the onset and particular location of granulomas, according to a main predisposing factor. Sixty-six subjects whose ages ranged from 18 to 73 years were studied. They were distributed into 4 groups according to the predominant cause of granuloma: intubation, vocal abuse, gastroesophageal reflux, and idiopathic causes. The larynx was evaluated during breathing, and the glottic proportion (GP) was measured. Glottic proportion is the mathematical ratio between the midsagittal dimension of the intermembranous region and that of the intercartilaginous region of the larynx during inhalation. Its measurement was feasible in 57 patients. The groups that had a causative factor other than laryngeal orotracheal intubation had GP values statistically similar to those of each other and to the control group of men, ie, close to 1.2. The postintubation group had GP values similar to the control group of women, ie, close to 1.0; this proportion protects the arytenoid region in women's larynges when there is effort during vocal production, but makes women susceptible to orotracheal postintubation granuloma.