Patients with positional OSAS have wider airways in the lateral parts, lower facial height, and more backward position of the lower jaw, which may explain differences in the maintenance of pharyngeal airway patency in the lateral sleep position.

To analyze the facial patterns of obstructive sleep apnea syndrome (OSAS) patients, we took lateral cephalograms of 31 OSAS patients and 26 non-OSAS controls and utilized Ricketts' method. In addition, we measured the hyoid bone position, the length of mandibular plane to Hpoint, the length of soft palate, and lower pharynx. The facial patterns of OSAS patients were dolico, the hyoid bone was positioned low, the soft palate was longer and the width of the airway was narrower than that of the non-OSAS controls.

The effectiveness of a tongue-retaining device (TRD) was examined at the baseline without any TRD [TRD(-)] and then with a TRD [TRD(+)] in eight patients with obstructive sleep apnea (OSA). In terms of the 3+ % oxygen desaturation index (ODI3), lowest percutaneous oxygen saturation (SpO 2 ), and time spent SpO 2 < 90%, there were significant differences (P < 0.01-0.05) between the findings for TRD(-) and TRD(+). The ODI3 dropped below the baseline by more than 50% in five patients (63%) and dropped to fewer than 10 events/ h in six patients (75%).The results indicate that oral appliances help patients with mild to moderate OSA; however, patients with more severe OSA may also be treated effectively with a TRD.

To determine which analysis is suitable to examine the dentofacial skeletal pattern characteristics of the obstructive sleep apnea syndrome (OSAS), we took lateral cephalograms of 44 Japanese OSAS patients and 34 Japanese non-OSAS controls. By Ricketts analysis, we found significant differences between OSAS patients and non-OSAS controls on facial axis, lower facial height and total facial height, which showed that Japanese OSAS patients have dolico facial patterns. However, by Downs-Northwestern analysis, we did not find any significant difference between OSAS patients and non-OSAS controls using the same cephalograms as the Ricketts analysis.

The facial patterns of 29 children under the age of 15 years with tonsil and/or adenoid and sleep disorder problems was analysed. The lateral-cephalograms of these patients was digitized in a zero-based computer program using Ricketts analysis to examine facial patterns. Results of the analysis were compared with the mean of the control group, n = 41 (9-year-old Japanese children). There were significant differences (P < 0.01-0.001) between the patient group and the control group when comparing the facial axis, lower facial height, mandibular arc, total facial height, and McNamara-Pogonion. The facial pattern of children with sleep breathing disorders was discovered to be the dolico facial pattern.