Evaluation of the relationship between stylohyoid complex morphology and maxillary/mandibular position using cone beam computed tomography.

BACKGROUND

The aim of this study was to examine the morphologic features of the stylohyoid complex (SHC) and its relation to maxillomandibular position using three-dimensional cone beam computed tomography (CBCT) images.

MATERIALS AND METHODS

CBCT images from 157 individuals (74 females, 83 males) were analysed in this study. SHC length, width, and sagittal and transverse angles were measured. The subjects were grouped as skeletal class I, II, and III in order to determine the relative positions of the maxilla and mandible in the sagittal plane and as hypodivergent, normodivergent, and hyperdivergent according to the vertical rotation of the mandible in relation to the skull base. Mann-Whitney U and Kruskal-Wallis H tests were used for statistical analysis.

RESULTS

Mean SHC length was 23.56 ± 8.05 mm on the right side and 22.0 ± 6.51 mm on the left; mean SHC width was 3.31 ± 1.40 mm on the right and 2.93 ± 1.30 mm on the left. Mean sagittal angle was 27.43 ± 6.75° on the right side, 27.70 ± 6.51° on the left; mean transverse angle was 70.39 ± 4.59° on the right side and 71.79 ± 4.99° on the left. The only significant difference based on skeletal classification was greater SHC length among males compared to females in the class III group (p < 0.05).

CONCLUSIONS

No significant relationship was observed between SHC morphology and position of the maxilla or mandible. However, the gender difference observed among class III subjects suggests that SHC morphology may be affected by craniofacial morphology. Maxillofacial surgeons should investigate this anatomical landmark variation before surgical interventions involving this region, such as temporomandibular joint procedures.