title: The usefulness of cephalometric measurement as a diagnostic tool for obstructive sleep apnea syndrome: a retrospective study.
abstract: OBJECTIVE
  Obstructive sleep apnea syndrome (OSAS) is a disorder characterized by apnea and hypopnea maintained for over 10 seconds and occurring at least 5 times per hour, with at least 30 episodes during 7 hours of nocturnal sleep. The most important pathophysiology in OSAS is the obstruction of the upper airway during sleep. The aim of this study was to identify the correlations between lateral cephalometric parameters, which seemed to be related to OSAS severities, and polysomnography (PSG) indices and to thus determine the cephalometric parameters reflecting OSAS severity.
  
  
  METHODS
  A total of 140 participants (122 males, 18 females) were evaluated by lateral cephalography and PSG. A total of 29 measurements (24 distances and 5 angles) were made on lateral cephalography. Cephalometric and PSG parameters were evaluated statistically to select and validate the cephalometric parameters reflecting OSAS severity.
  
  
  RESULTS
  OSAS has a significant relationship with the anatomic deformities of craniofacial and soft tissues. Lateral cephalometry revealed that patients with OSAS have a significant vertical airway length, a regrognathic mandible, a thick uvula, a large tongue, and a long mid-face length. The position of the hyoid bone had a tendency to displace inferiorly and/or posteriorly. Using the discriminant variable combination, including tongue base-posterior nasal spine (T1-PNS), sella-nasion-B point angle (SNB), maximum uvula thickness (Max U), tongue base-tongue tip (T1-TT), and nasion-anterior nasal spine (N-ANS), 102 of 140 (72.9%) patients were correctly assigned to the normal-to-mild and moderate-to-severe apnea-hypopnea index (AHI) groups.
  
  
  CONCLUSIONS
  Lateral cephalometric radiography may be an accessible and suitable tool for evaluation of craniofacial and soft tissue deformities in their correlations with OSAS severity. Further research on the cephalometric parameters reflecting OSAS severity is needed.
authors.affiliation: Postgraduate, Department of Oral and Maxillofacial Surgery, Dong-a University Medical Center, Busan, Korea.
authors.forename: Hyun-Ho
authors.initials: HH
authors.lastname: Ryu
authors.affiliation: Professor, Department of Oral and Maxillofacial Surgery, Dong-a University Medical Center, Busan, Korea.
authors.forename: Chul-Hoon
authors.initials: CH
authors.lastname: Kim
authors.affiliation: Associate Professor, Department of Neurology, Dong-a University Medical Center, Busan, Korea.
authors.forename: Sang-Myung
authors.initials: SM
authors.lastname: Cheon
authors.affiliation: Associate Professor, Department of Otorhinolaryngology, Dong-a University Medical Center, Busan, Korea.
authors.forename: Woo-Yong
authors.initials: WY
authors.lastname: Bae
authors.affiliation: Professor, Department of Neurology, Dong-a University Medical Center, Busan, Korea.
authors.forename: Sang-Ho
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Chief, Department of Otorhinolaryngology, Busan Saint Mary's Hospital, Busan, Korea.
authors.forename: Soo-Kweon
authors.initials: SK
authors.lastname: Koo
authors.affiliation: Associate Professor, Department of Nursing, Pukyong National University, Busan, Korea.
authors.forename: Myoung-Soo
authors.initials: MS
authors.lastname: Kim
authors.affiliation: Assistant Professor, Department of Oral and Maxillofacial surgery, Dong-a University Medical Center, Busan, Korea. Electronic address: omsbjkim@dau.ac.kr.
authors.forename: Bok-Joo
authors.initials: BJ
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002508:Cephalometry; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D011859:Radiography; D012189:Retrospective Studies; D012720:Severity of Illness Index; D012891:Sleep Apnea Syndromes / Q000000981:diagnostic imaging*