Long-term changes of hyoid bone and pharyngeal airway size following advancement of the mandible.
OBJECTIVE
To determine long-term changes in hyoid bone position and pharyngeal airway size after mandibular advancement, including evaluation of the relationship between length of suprahyoidal musculature and skeletal relapse.


METHODS
A cephalometric follow-up study (12 years) of 15 patients who underwent mandibular advancement surgery.


RESULTS
The final position of the hyoid bone was more posterior than it had been preoperatively. Suprahyoidal musculature continuously lengthened from preoperatively to 12 years postoperatively. Total skeletal relapse at B-point and pogonion correlated significantly with postoperative stretch of suprahyoidal musculature. The upper and middle pharyngeal airways were narrower than their preoperative values.


CONCLUSIONS
Mandibular changes influence hyoid bone position during the entire postoperative period, whereas stretching of suprahyoidal musculature seems to contribute to skeletal relapse. Mandibular advancement surgery alone possibly does not achieve a stable increase of pharyngeal airway size over a long-term period of 12 years.
Eggensperger
Nicole
N
Department of Cranio-Maxillofacial Surgery, University of Berne, Inselspital, CH-3010 Berne, Switzerland. nicole.eggensperger@insel.ch
Smolka
Koord
K
Johner
Alexander
A
Rahal
Akram
A
Thüer
Urs
U
Iizuka
Tateyuki
T
D000293:Adolescent; D000328:Adult; D002508:Cephalometry; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006928:Hyoid Bone / Q000033:anatomy & histology*; D008297:Male; D008312:Malocclusion, Angle Class II / Q000601:surgery; D019186:Mandibular Advancement; D009334:Neck Muscles / Q000033:anatomy & histology*; D010614:Pharynx / Q000033:anatomy & histology*; D012008:Recurrence; D020181:Sleep Apnea, Obstructive / Q000601:surgery; D018709:Statistics, Nonparametric