Akiko Takeuchi1,2, Hideki Hyodoh1,3, Kotaro Matoba1,3, Manabu Murakami4, Kohsuke Kudo1,5, Kazuyuki Minowa6,7,8. 1. Center for Cause of Death Investigation, Graduate School of Medicine, Hokkaido University, Sapporo, Japan. 2. Faculty of Dental Medicine, Department of Radiology, Hokkaido University, Sapporo, Japan. 3. Department of Forensic Medicine, Graduate School of Medicine, Hokkaido University, Sapporo, Japan. 4. International Relations Office, Graduate School of Medicine, Hokkaido University, Sapporo, Japan. 5. Department of Diagnostic Imaging, Hokkaido University Graduate School of Medicine, Sapporo, Japan. 6. Center for Cause of Death Investigation, Graduate School of Medicine, Hokkaido University, Sapporo, Japan. kminowa@den.hokudai.ac.jp. 7. Faculty of Dental Medicine, Department of Radiology, Hokkaido University, Sapporo, Japan. kminowa@den.hokudai.ac.jp. 8. , N13 W7, Kita-ku, Sapporo, Hokkaido, 060-8586, Japan. kminowa@den.hokudai.ac.jp.
Abstract
OBJECTIVES: Obstructive sleep apnea syndrome (OSAS) induces upper airway occlusion and may cause sudden death during sleep. This study sought to clarify the relationship between oral air space volume and OSAS onset, which is influenced by multiple factors, such as jawbone, dentition morphology, and oral soft-tissue volume. METHODS: (1) 50 subjects from deceased cases were divided into two groups: OSAS (25 subjects) and controls (25 subjects). (2) 28 subjects from clinical cases were divided into two groups: OSAS (9 subjects) and controls (19 subjects). In all cases, the Computed Tomography (CT) images of the facial region were obtained, and four parameters of oral area volume were analyzed in deceased and clinical cases, and comparisons and analyses were performed between OSAS and control cases. In addition, the efficiency of measurement of these parameters was evaluated using Receiver Operating Characteristic (ROC) curves in OSAS. RESULTS: (1) In deceased cases, oral soft-tissue volume (OSV), oral air-space volume (OAV), and the ratio of OAV to OSV (%air) showed a significant correlation. (2) In clinical cases, OAV and %air showed a significant correlation. In both postmortem and clinical images, a small %air value indicates a high risk of developing OSAS and a high probability of OSAS-related sudden death. CONCLUSIONS: It was shown that the %air is an index to evaluate OSAS by CT imaging of the oral region. OSAS may be indicated when the %air value is ≦ 16.0% in deceased cases and ≦ 6.6% in clinical cases.
OBJECTIVES: Obstructive sleep apnea syndrome (OSAS) induces upper airway occlusion and may cause sudden death during sleep. This study sought to clarify the relationship between oral air space volume and OSAS onset, which is influenced by multiple factors, such as jawbone, dentition morphology, and oral soft-tissue volume. METHODS: (1) 50 subjects from deceased cases were divided into two groups: OSAS (25 subjects) and controls (25 subjects). (2) 28 subjects from clinical cases were divided into two groups: OSAS (9 subjects) and controls (19 subjects). In all cases, the Computed Tomography (CT) images of the facial region were obtained, and four parameters of oral area volume were analyzed in deceased and clinical cases, and comparisons and analyses were performed between OSAS and control cases. In addition, the efficiency of measurement of these parameters was evaluated using Receiver Operating Characteristic (ROC) curves in OSAS. RESULTS: (1) In deceased cases, oral soft-tissue volume (OSV), oral air-space volume (OAV), and the ratio of OAV to OSV (%air) showed a significant correlation. (2) In clinical cases, OAV and %air showed a significant correlation. In both postmortem and clinical images, a small %air value indicates a high risk of developing OSAS and a high probability of OSAS-related sudden death. CONCLUSIONS: It was shown that the %air is an index to evaluate OSAS by CT imaging of the oral region. OSAS may be indicated when the %air value is ≦ 16.0% in deceased cases and ≦ 6.6% in clinical cases.