Changes in Hyoid Bone Position Before and After Distraction Osteogenesis in Infants With Robin Sequence

Abstract

Purpose: To study the changes of hyoid position in infants with Robin sequence before and after mandibular distraction osteogenesis, and to explore the related factors. Material and Methods: Twenty-six infants with Robin sequence underwent bilateral mandibular distraction osteogenesis from May 2016 to April 2020. Three-dimensional computed tomography data of patients before and after surgery were analyzed with Materialise Mimics 17.0. Changes in the three-dimensional position of the hyoid bone were studied. Results: The angle between the long axis of the tongue body and hard palate plane, and the angle between the long axis of the tongue body and mandibular plane were significantly decreased after surgery than before surgery. The hyoid bone-cranial base vertical distance, hyoid bone-mental point distance, and hyoid bone -epiglottis distance were significantly increased after surgery. The differences in the abovementioned data were statistically significant (P < 0.05). Changes in the angle between the long axis of the tongue body and the hyoid bonemental point line correlated with changes in the position of the hyoid bone relative to the cervical spine (P ¼ 0.006). Postoperatively, the hyoid bone moved forward and the increase in the hyoid bone -mental point osseous distance interval (41.28%) was significantly greater than the increase in the hyoid bone-epiglottis distance (18.73%). Differences in the total mandibular length and the hyoid bone -cranial base vertical distance are related to the age at the operation (P < 0.05). The younger the age at the time of surgical intervention, the greater the difference before and after surgery for the same follow-up interval. Conclusions: The three-dimensional direction of the hyoid bone changes after the distraction osteogenesis of the mandible, and the hyoid bone moves downward and forward. Because the mandibular length and airway changed, the relative positions of the long axis of the tongue body on the sagittal plane rotated clockwise.

Hyoid bone morphology in patients with isolated robin sequence – A case-control study utilizing 3D morphable models

“…Abnormalities of hyoid bone position are of particular importance in the pathogenesis of upper airway obstruction due to its central role in the aerodigestive tract. Mandibular distraction osteogenesis (MDO), an operation commonly used to relieve upper airway obstruction in infants with RS, has been shown to lead to both mandibular lengthening and anterior displacement of the hyoid ( Li et al, 2022 ; Mahrous Mohamed et al, 2011 ). This advancement typically leads to an increase in airway patency and resolution of upper airway obstruction ( Roy et al, 2009 ).…”