Statistical model estimating the occurrence of otitis media from temporal bone pneumatization.

In order to investigate the relationship between the pneumatization of temporal bones and the occurrence of otitis media in Greenlandic Inuit, 36 Greenlandic Inuit were examined by radiography of the temporal bones. The pneumatized cell area was measured planimetrically. All subjects answered a questionnaire on infectious middle ear disease (IMED), and an objective otologic examination was performed. Nine persons of 34 (26%) reported IMED in childhood, and there was IMED reported in all pneumatized areas below 400 mm2. Based on bilateral area measures, a polychotomous logistic regression model was applied. The occurrence of IMED was shown to be associated with smaller areas, and unilateral IMED was associated with pronounced asymmetry. The model has enabled risk assessment, and 8 persons were designated by the model as having had IMED with a sensitivity of 67% (confidence interval 30% to 93%) and a specificity of 92% (confidence interval 74% to 99%). When the model was applied to a historical anthropological Inuit material from 1700 to 1800 AD, 6 of 56 crania were designated as having had IMED. This method has improved the accuracy of estimating the occurrence of IMED in ancient populations.