Evaluation of craniofacial morphology in patients with obstructive sleep apnea using lateral cephalometry and dynamic MRI.

Context: Obstructive sleep apnea (OSA) is a potentially life-threatening disorder, characterized by repeated collapse of the upper airway during sleep with cessation of breathing. The altered mouth breathing produces morphological changes in craniofacial region. Aim: This study was designed to compare and validate the craniofacial morphological characteristics in patients with OSA using lateral cephalometry and to investigate the dentofacial characteristics of patients with OSA with respect to the obstructive sites determined by dynamic magnetic resonance imaging (MRI) to more accurately clarify the pathophysiological features. Materials and Methods: 10 patients with OSA were divided into two groups of five each according to their obstructive site determined by dynamic MRI. (1) Obstruction at the retropalatal and retroglossal region (Rp + Rg group) and (2) obstruction at the retropalatal region (Rp group). Lateral cephalogram both in upright and supine position was taken for all the subjects. In addition, dynamic MRI was performed to identify the sites of obstruction of the upper airway. Statistical analysis used: Independent t-test was performed to evaluate the significant difference in the upright cephalometric variables between the study and control group and between the two groups. The changes in skeletal and soft tissue parameters with change in posture was assessed within the study and control group by paired t test. P value of ≤0.05 was considered as statistically significant. Results: The study indicated that the first group of patients with both retropalatal and retroglossal obstruction showed signs of skeletal discrepancy that predisposed to obstruction at the retroglossal level and the soft tissue components like the soft palate and tongue that contributed to retropalatal obstruction. However, the second group of patients with only retropalatal obstruction had primarily soft tissue components associated with increased BMI that contributed to retropalatal obstruction. Conclusion: Evaluation of craniofacial morphology in OSA patients is bound to help the concerned specialist in recognizing the morphological changes induced by altered sleep pattern so as to provide the appropriate treatment.

Does the Oropharyngeal Fat Tissue Influence the Oropharyngeal Airway in Snorers? Dynamic CT Study

OBJECTIVE: The aim of this study was to determine if snorers have a narrower oropharyngeal airway area because of fat infiltration, and an elevated body mass index. MATERIALS AND METHODS: Ten control subjects and 19 patients that snored were evaluated. We obtained 2-mm-thick axial CT scan images every 0.6 seconds during expiration and inspiration at the same level of the oropharynx. We selected the largest and the smallest oropharyngeal airway areas and found the differences. From the slice that had the smallest oropharyngeal airway area, the thickness of the parapharyngeal and subcutaneous fat was measured. The measurements from the left and right side were added together and single values for parapharyngeal and subcutaneous fat tissue thickness were then found. RESULTS: The conventional measure of body mass index was significantly higher in the snorers (p 0.05). CONCLUSION: We concluded that the oropharyngeal fat deposition in snorers is not an important factor, and it does not predispose a person to the upper airway narrowing.