Relationship between craniocervical posture, mandible and hyoid bone and influence on alimentary functions

ABSTRACT

Aim: To evaluate the anatomical relationship between craniocervical posture and mandibularand hyoid bone position and the influence on the masticatory and swallowing functions. Methods:Thirty-six women aged 19 to 35 years without temporomandibular disorder diagnosis wereevaluated. Variables related to the craniocervical posture and mandibular and hyoid boneposition were obtained by cephalometric measurements. Masticatory and swallowing functionevaluations were performed according to a protocol of orofacial myofunctional evaluation withscores. Results: Significant correlations were observed between craniovertebral angle and thelinear distance from the hyoid bone to the mentum (p=0.02) and to the mandible (p=0.03). Theangle that measured the forward head position also demonstrated a significant correlation with thelinear distance between hyoid bone and jaw (p=0.00). The cervical curvature degree showed asignificant correlation with the linear distance from hyoid bone to the third cervical vertebra(p=0.01). Modifications of the cranium base inclination in relation to the cervical column at the twolevels (NSL/CVT and NSL/OPT) were the only variables, which showed a significant correlationwith the mandible position. Important craniocervical postural changes were observed in thesubjects, although there was no association between them and a higher frequency of atypicalbehaviors evaluated during masticatory and swallowing functions. Conclusions: Cephalometricfindings confirm the anatomical relationship between craniocervical posture, mandible and hyoidbone. However, association between craniocervical posture alterations and masticatory and swallowingfunction impairments was not detected. Such findings suggest that, in the presence of a musculoskeletalimbalance, the body readapts itself ensuring that alimentary functions will not be affected.