Contribution of postero-anterior cephalometry in obstructive sleep apnea.

OBJECTIVES/HYPOTHESIS: Lateral cephalometry has been widely used to characterize facial and maxillary morphology in obstructive sleep apnea (OSA) patients. It is a useful tool to assess orthodontic and maxillofacial procedures, but transverse dimensions of the airway (e.g., nasal framework) have not been well described yet by cephalometry. We explored whether postero-anterior cephalometry could refine the analysis of the facial morphology, with a special attention paid to nasal morphology. We validated cephalometric measurements relevant to the diagnosis of OSA. STUDY DESIGN: Controlled study. METHODS: We explored postero-anterior and lateral cephalometric bony structures in OSA patients and in control subjects to determine which were predictive of an association with OSA. Healthy volunteers paired for age and sex to OSA patients underwent polysomnography and cephalometry. Data were analyzed by Shapiro-Wilk, Fisher, Wilcoxon, and paired t tests where appropriate. RESULTS: Nasal fossae and maxillary bone proportions were positively and independently associated with the absence of OSA. Measurements of maxillary width, nasal fossae angle, and anterior skull base contributed to the characterization of OSA patients. CONCLUSIONS: Postero-anterior cephalometry is an easy, rapid, informative, and reliable technique, which is complementary to the lateral cephalometry in the assessment of OSA patients. Our study may also suggest the negative impact of the nasal resistance on the upper airway resistance in sleep disorders.