Relationship between morphological characteristics of hyoid bone and mandible in Japanese cadavers using three-dimensional computed tomography

Changes in Hyoid Bone Position before and after Distraction Osteogenesis in Infants with Robin Sequence

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 above-mentioned data were statistically significant (P < 0.05). Changes in the angle between the long axis of the tongue body and the hyoid bone-mental point line correlated with changes in the position of the hyoid bone relative to the cervical spine (P = 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.

Growth and sexual dimorphism of the hyoid bone and its relationship to the mandible from birth to 19 years: A three-dimensional computed tomography study

The hyoid bone and the hyomandibular complex subserve the functions of respiration, deglutition, and speech. This study quantified the growth of the hyoid bone and the hyomandibular relationships in males and females from birth to 19 years. Using 97 computed tomography (CT) scans, from a previous study (Kelly et al., 2017) on mandibular growth from 49 individuals (16 with longitudinal scans), landmarks were placed on 3D CT models and used to calculate four distance, and three angular measurements. A general increase in growth trend was observed in hyoid bone linear measurements-length, width, and depth-as well as relational mandible-to-hyoid distance, throughout the developmental ages examined in both males and females, with most variables having larger measurements for females up to age 10 years. A general decrease in all three angular measurements was observed in both males and females up to approximately age 12 years, at which time male angular measurements gradually increased with significant sexual dimorphism emerging after age 15 years. As expected, postpubertal males had greater hyoid angle than females; they also had greater hyoid angle of inclination than mandible body inclination (with inclination relative to the anterior-posterior nasal plane), likely related to hyo-laryngeal descent. This study contributes to normative data on hyoid bone and hyomandibular relational growth in typically developing individuals and provides a baseline against which structural and functional influences on anatomic growth may be examined by clinical disciplines that address the aerodigestive and speech functions, as well as the fields of anatomy, forensics, and anthropology.