Clinical Paper TMJ Disorders Prevalence and characteristics of pneumatization of the temporal bone evaluated by cone beam computed tomography D. B. S. Ladeira, G. L. R. Barbosa, M. C. C. Nascimento, A. D. Cruz, D. Q. Freitas, S. M. Almeida: Prevalence and characteristics of pneumatization of the temporal bone evaluated by cone beam computed tomography. Int. J. Oral Maxillofac. Surg. 2013; 42: 771–775. # 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. D. B. S. Ladeira 1 , G. L. R. Barbosa 1 , M. C. C. Nascimento 1 , A. D. Cruz 2 , D. Q. Freitas 1 , S. M. Almeida 1 1 Oral Radiology Area, Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas, Piracicaba, SP, Brazil; 2 Department of Specific Formation of the Dental School, Area of Oral Radiology, University Center of Nova Friburgo of the Fluminense Federal University, Brazil Abstract. The aim of this study was to determine the prevalence and characteristics of pneumatization of the glenoid fossa and articular eminence by means of cone beam computed tomography (CBCT) images. CBCT images of 658 patients (1316 joints) were evaluated to determine pneumatization in the articular eminence (PAT) and roof of the glenoid fossa (PGF). Age and gender were recorded for all patients and, for the cases of pneumatization, laterality and type (unilocular or multilocular) were noted. Its prevalence was correlated with gender, age and laterality by statistical analyses. 21.3% of individuals presented with PAT and 38.3% presented with PGF. Considering the temporomandibular joint, PAT was in 15.5% and PGF in 30.2%. Of PAT cases, 54.3% were unilateral and 45.7% bilateral; 3.4% were unilocular and 96.6% were multilocular. In the PGF cases, 42.5% were unilateral and 57.5% bilateral; 0.02% was unilocular and 99.8% were multilocular. There was no statistical difference regarding gender and age; but there was statistical difference regarding laterality, with higher frequency on the left side. In conclusion, there was a significant prevalence of PAT and PGF in the studied population; their prevalence seems higher than has been previously supposed. Keywords: pneumatized articular eminence; temporal bone; temporomandibular joint; cone beam computed tomography. Accepted for publication 5 December 2012 Available online 4 January 2013 The bones of the skull contain many air- filled cavities, which are referred to as pneumatization. Ten sites of air cells can be found within the temporal bone, including the zygomatic process of the temporal bone 1,11 which is termed the pneumatized articular eminence (PAT) and the roof of the glenoid fossa. 2 The term PAT was used for the first time by Tyndall and Matteson 12 to describe air cells that occur in the root of the zygo- matic arch and in the articular eminence of the temporal bone, that is, similar to air cells in the mastoid process and ethmoid bone. These authors also identified its common characteristics as: an asymptomatic radiolucent defect in the zygomatic process of the temporal bone with an appearance similar to mastoid air cells; extension of the defect anteriorly as far as the articular eminence but not beyond the zygomaticotemporal suture; and no enlargement or cortical destruction of the zygoma. Additionally, Int. J. Oral Maxillofac. Surg. 2013; 42: 771–775 http://dx.doi.org/10.1016/j.ijom.2012.12.001, available online at http://www.sciencedirect.com 0901-5027/060771 + 05 $36.00/0 # 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.