Studies On Treating Obstructive Sleep Apnea Syndrome (OSAS) With Bite Plate Appliances And The Changes Of Upper Airway Of OSAS Patients After The Treatment

Objective:The purpose of this study was to research the feature of the craniofacial skeletal structure in OSAS patients; to investigate the differences of upper airway volume and around it structure in OSAS patients after effective oral appliances treatment; and comparison between the two kinds of oral appliance; meanwhile, to introduce a better new method to OSAS-the oral appliance of bite plates and mandibular antedisplacement with class II elastics.Methods:28 patients of mild and moderate OSAS were divided randomly into two groups. The two groups used the different mandibular advancement applianees respectively . A comprehensive cephalometric analysis of the upper airway and craniofaeial skeletal structure in patients with OSAS was performed. After treatment with oral appliances about three monthes , all OSAS patients were re-examined by polysomnography. And evaluated the fixation and comfort of the oral appliances by themselves. Furthermore, this study was designed to evaluate, on the basis of linear correlation analysis , whether any cephalometric variable could be used as potential predictors of the effectiveness of the oral appliances. And the statistics analysis adopted the software of spssl2.0.Results: 1. The results in upper airway and craniofacial skeletal structure of the patients was observed。ANB,SN-MP,SPP-SPPW,U-MPW,PAS,CL,TT-PP, There were significant differences between the OSAS patients before the treatment and which after the treatment。2. The cinical effectiveness of the mandibular advancement appliances was obvious: AHI 4. 90±3. 50, AI 4. 95±3. 28 <90%SaO₂ 6. 95±6. 12. The objective successful percentage was 88. 0%. Most of the patients who did not improve substantially were belonged to the patients whose mandibular were not more posteriorly. Furthermore, there existed linear correlation between the improvement of AHI and the morphology of the craniofacial skeletal structure.3. The effectiveness of the two kinds of oral appliance was similar, but the comfort was different.Conclusion:1. The significant aberration in upper airway and craniofacial skeletal structure of the patients was observed。: the mandibular was more posteriorly positioned, the angle of mandibular plane was higher, the oropharyngeal airway space was significantly narrower, the length of soft palate and tongue were longer, the hyoidbone was located more inferiorly.2. The oral appliances were significantly effective in most of the OSAS patients . The objective sueeessful percentage was 88. 0%. Most of the patients who did not improve substantially belonged to the patients whose mandibular were not more posteriorly. Furthermore, there existed linear correlation between the improvement of AHI and the morphology of the craniofacial skeletal structure. The larger the mandibular plane angle, the longer the height of hyoid, the longer the length of soft palate, the less the improvement of AHI. The larger the angle of ANB, the more the improvement of AHI。So, before apply the oral appliance to treat OSAS patients, we could use some cephalometric variables as potential predictors of the effectiveness of the oral appliance.3 . Although the mandibular advancement appliances were different, the mechanism was the same. So the effectiveness of the oral appliances was similar. But the comfortable of the oral appliances was significantly different. The patients preferred to the appliance with two pieces allowed for mouth opening and side-to-side movement of the mandibular to the one piece appliance.