Study for the etiological diagnosis of obstructive sleep apnea and survey in oral and maxillofacial diseases.

1994 Fiscal Year Final Research Report Summary

• Project/Area Number: 05671664
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: Surgical dentistry
• Research Institution: Niigata University
• Principal Investigator: KOHNO Masaki Niigata University, Dental Hospital, Lecturer, 歯学部附属病院, 講師 (20170201)
• Co-Investigator(Kenkyū-buntansha): KOBAYASHI Tadaharu Niigata University, Dental Hospital, Assistant Professor, 歯学部附属病院, 助手 (80195792) ; SEO Kenji Niigata University, Dental Hospital, Assistant Professor, 歯学部附属病院, 助手 (40242440)
• Project Period (FY): 1993 – 1994
• Keywords: Oral and maxillofacial disease / Sleep apnea syndrome / Sleep oximetry / Contrasted lateral cephalogram / Excess of soft palate / Distance between palatal plane and hyoid bone / Mean pharyngeal airway space / Airway Analyzing Chart

Research Abstract

In spite of variant anatomic deformities claimed as etiologic factors for OSA,the morphologic analysis of this condition has not been well established. In this study, a new method of diagnosing the etiology and the severity of OSA was studied.
To diagnose any patients as OSA,the Sleep Oximetry which was a method applicable even to uncooperative child for diagnosis of OSA instead of polysomnography was developed. A parameter, %TSpO_2<90 which was the percentage of the time spent below 90% of SpO2 was related to the apnea/hypopnea index (AHI) closely and seemed to be useful for physiological diagnosis of OSA.
On the other hand, a study was designed to establish a new method of diagnosing the etiology of OSA using contrasted lateral cephalograms. The subjects of the study consisted of 13 patients who had undergone surgical treatment of OSA.Twenty six pairs of cephalograms and polysomnograms taken pre/postoperatively were used for the analysis. As result, two Airway Analyzing Charts (AAC) were obtained from the multivariate analysis. One regression equation was (AHI)=1.48(EX)-2.63(mPAS)+32.6 with an R^2 value of 0.70, where mPAS is the average width of the posterior airway space in mm and EX is the length of the soft palate in excess of the pharyngeal depth in mm. The other was (AHI)=1.62(EX)+0.98(PPH)-74.9 with an R^2 value of 0.71, where PPH is the distance from the palatal plane to the hyoid bone in mm.
The incidence of OSA in the oral and maxillofacial diseases was investigated with Sleep Oximetry and AACs and then many OSAs were found in the various conditions such as retromandible (microgenia, agnathia, RA), Pierre-Robin syndrome, Crouzon syndrome, postpalatoplasty and maxillomandibular fixation. In conclusion, it seems that many oral and maxillofacial surgeons merely have not become aware of OSAs which have been occurring even in the common diseases of oral and maxillofacial region.