Head posture and pharyngeal airway volume changes after bimaxillary surgery for mandibular prognathism.
OBJECTIVE
The purpose of this study was to evaluate head posture and the pharyngeal airway volume changes using 3D imaging after bimaxillary surgery in mandibular prognathism patients by null hypothesis.


METHODS
Cone-beam computed tomography (CBCT) scans were obtained for 25 mandibular prognathism patients before bimaxillary surgery (T1) and 6 months after surgery (T2). The head posture of each patient was assessed by measuring cranio-cervical angle on a midsagittal plane passing through the anterior nasal spine at T1 and T2. Additionally, the volume of each subject's pharyngeal airway was measured using InVivoDental 3D imaging software.


RESULTS
The cranio-cervical angle increased significantly 6 months after bimaxillary surgery (p < 0.01). The total volume of the pharyngeal airway slightly decreased (p > 0.05) at the same timepoints, while naso- and oro-pharyngeal airway volume decreased significantly (p < 0.05, p < 0.05). There was significant relationship between the changes of head posture and those of total airway volume (p < 0.05).


CONCLUSIONS
The null hypothesis was rejected. Bimaxillary surgery resulted in significant head flexion and a slight decrease in total pharyngeal airway volume.
Department of Orthodontics, Kangdong Sacred Heart Hospital, Hallym University Medical Center, Gil-dong 445, Gangdong-gu, Seoul 134-701, Republic of Korea.
Min-Ah
MA
Kim
Department of Orthodontics, Kangdong Sacred Heart Hospital, Hallym University Medical Center, Gil-dong 445, Gangdong-gu, Seoul 134-701, Republic of Korea.
Bo-Ram
BR
Kim
Graduate School of Hallym University, Seoul, Republic of Korea.
Jong-Kuk
JK
Youn
Department of Orthodontics, Kangdong Sacred Heart Hospital, Hallym University Medical Center, Gil-dong 445, Gangdong-gu, Seoul 134-701, Republic of Korea.
Yoon-Ji R
YJ
Kim
Department of Orthodontics, Kangdong Sacred Heart Hospital, Hallym University Medical Center, Gil-dong 445, Gangdong-gu, Seoul 134-701, Republic of Korea. Electronic address: dentpark64@hanmail.net.
Yang-Ho
YH
Park
D000293:Adolescent; D000328:Adult; D002508:Cephalometry / Q000379:methods; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging; D002680:Chin / Q000000981:diagnostic imaging; D054893:Cone-Beam Computed Tomography / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D063172:Genioplasty / Q000379:methods; D006257:Head / Q000033:anatomy & histology*; D006801:Humans; D006928:Hyoid Bone / Q000000981:diagnostic imaging; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D008313:Malocclusion, Angle Class III / Q000601:surgery; D008875:Middle Aged; D009295:Nasal Bone / Q000000981:diagnostic imaging; D009305:Nasopharynx / Q000033:anatomy & histology; D009929:Organ Size; D009960:Oropharynx / Q000033:anatomy & histology; D019340:Osteotomy, Le Fort / Q000379:methods*; D059229:Osteotomy, Sagittal Split Ramus / Q000379:methods*; D010614:Pharynx / Q000033:anatomy & histology*; D011187:Posture; D011378:Prognathism / Q000601:surgery*; D019291:Skull Base / Q000000981:diagnostic imaging; D055815:Young Adult
CBCT; Head posture; Orthognathic surgery; Pharyngeal airway