title: Effect of bimaxillary rotational setback surgery on upper airway structure in skeletal class III deformities.
abstract: BACKGROUND
  Upper airway narrowing has been a concern of mandibular setback. The aims of this study were (1) to evaluate the effect of bimaxillary rotational setback surgery on upper airway structure in patients with skeletal class III deformities, and (2) to compare the preoperative and postoperative upper airways of class III patients with age- and sex-matched class I control subjects.
  
  
  METHODS
  The upper airways of 36 adults who consecutively underwent bimaxillary rotational setback surgery for skeletal class III deformities were assessed by means of cone-beam computed tomography before and at least 6 months after surgery. Results were compared with those of age- and sex-matched control subjects with skeletal class I structure.
  
  
  RESULTS
  Before surgery, the class III patients had significantly larger velopharyngeal, oropharyngeal, and hypopharyngeal volumes than did the control subjects (all p < 0.01). The velopharyngeal, oropharyngeal, and hypopharynx volumes decreased significantly after surgery (all p < 0.01). The postoperative airways of class III patients were similar with regard to velopharyngeal, oropharyngeal, and hypopharyngeal volume (all p > 0.01) compared to control subjects. The postoperative velopharyngeal and oropharyngeal airway volumes were associated with the baseline airway volume (p < 0.001) and horizontal movement of the soft palate (p < 0.01).
  
  
  CONCLUSIONS
  These results suggest that upper airway volume is decreased after bimaxillary rotational setback surgery for skeletal class III deformities, but is not smaller than in normal controls, and the postoperative upper airway volume is related to airway volume at baseline and changes in the surrounding structures.
  
  
  METHODS
  Therapeutic, III.
authors: Taoyuan and Linkou, Taiwan From the Craniofacial Center and Department of Craniofacial Orthodontics, Chang Gung Memorial Hospital; the Craniofacial Research Center and Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital; and the College of Medicine, Chang Gung University.
authors: Yuh-Jia
authors: YJ
authors: Hsieh
authors: Yi-Chieh
authors: YC
authors: Chen
authors: Yin-An
authors: YA
authors: Chen
authors: Yu-Fang
authors: YF
authors: Liao
authors: Yu-Ray
authors: YR
authors: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D000402:Airway Obstruction / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology; D054893:Cone-Beam Computed Tomography; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008313:Malocclusion, Angle Class III / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D008437:Maxilla / Q000601:surgery*; D009068:Movement; D009929:Organ Size; D019340:Osteotomy, Le Fort; D010160:Palate, Soft / Q000000981:diagnostic imaging / Q000473:pathology; D010614:Pharynx / Q000000981:diagnostic imaging / Q000473:pathology; D012399:Rotation; D020181:Sleep Apnea, Obstructive / Q000209:etiology; D016896:Treatment Outcome; D055815:Young Adult
references: Chang HP. Components of class III malocclusion in Taiwanese (in Chinese). Kaohsiung J Med Sci. 1985;1:144–155
references: Baik HS, Han HK, Kim DJ, Proffit WR. Cephalometric characteristics of Korean class III surgical patients and their relationship to plans for surgical treatment. Int J Adult Orthodon Orthognath Surg. 2000;15:119–128
references: Baik HS. Limitations in orthopedic and camouflage treatment for class III malocclusion. Semin Orthod. 2007;13:158–174
references: Kawakami M, Yamamoto K, Fujimoto M, Ohgi K, Inoue M, Kirita T. Changes in tongue and hyoid positions, and posterior airway space following mandibular setback surgery. J Craniomaxillofac Surg. 2005;33:107–110
references: Riley RW, Powell NB, Guilleminault C, Ware W. Obstructive sleep apnea syndrome following surgery for mandibular prognathism. J Oral Maxillofac Surg. 1987;45:450–452
references: Saitoh K. Long-term changes in pharyngeal airway morphology after mandibular setback surgery. Am J Orthod Dentofacial Orthop. 2004;125:556–561
references: Eggensperger N, Smolka W, Iizuka T. Long-term changes of hyoid bone position and pharyngeal airway size following mandibular setback by sagittal split ramus osteotomy. J Craniomaxillofac Surg. 2005;33:111–117
references: Enacar A, Aksoy AU, Sençift Y, Haydar B, Aras K. Changes in hypopharyngeal airway space and in tongue and hyoid bone positions following the surgical correction of mandibular prognathism. Int J Adult Orthodon Orthognath Surg. 1994;9:285–290
references: Samman N, Tang SS, Xia J. Cephalometric study of the upper airway in surgically corrected class III skeletal deformity. Int J Adult Orthodon Orthognath Surg. 2002;17:180–190
references: Tselnik M, Pogrel MA. Assessment of the pharyngeal airway space after mandibular setback surgery. J Oral Maxillofac Surg. 2000;58:282–285
references: Guijarro-Martínez R, Swennen GR. Cone-beam computerized tomography imaging and analysis of the upper airway: A systematic review of the literature. Int J Oral Maxillofac Surg. 2011;40:1227–1237
references: Hong JS, Oh KM, Kim BR, Kim YJ, Park YH. Three-dimensional analysis of pharyngeal airway volume in adults with anterior position of the mandible. Am J Orthod Dentofacial Orthop. 2011;140:e161–e169
references: Jakobsone G, Stenvik A, Espeland L. The effect of maxillary advancement and impaction on the upper airway after bimaxillary surgery to correct class III malocclusion. Am J Orthod Dentofacial Orthop. 2011;139(Suppl):e369–e376
references: Lee Y, Chun YS, Kang N, Kim M. Volumetric changes in the upper airway after bimaxillary surgery for skeletal class III malocclusions: A case series study using 3-dimensional cone-beam computed tomography. J Oral Maxillofac Surg. 2012;70:2867–2875
references: Park SB, Kim YI, Son WS, Hwang DS, Cho BH. Cone-beam computed tomography evaluation of short- and long-term airway change and stability after orthognathic surgery in patients with class III skeletal deformities: Bimaxillary surgery and mandibular setback surgery. Int J Oral Maxillofac Surg. 2012;41:87–93
references: Schwab RJ, Gefter WB, Hoffman EA, Gupta KB, Pack AI. Dynamic upper airway imaging during awake respiration in normal subjects and patients with sleep disordered breathing. Am Rev Respir Dis. 1993;148:1385–1400
references: Chen F, Terada K, Hanada K, Saito I. Predicting the pharyngeal airway space after mandibular setback surgery. J Oral Maxillofac Surg. 2005;63:1509–1514
references: Liukkonen M, Vähätalo K, Peltomäki T, Tiekso J, Happonen RP. Effect of mandibular setback surgery on the posterior airway size. Int J Adult Orthodon Orthognath Surg. 2002;17:41–46