Does Head Posture Have a Significant Effect on the Hyoid Bone Position and Sternocleidomastoid Electromyographic Activity in Young Adults?

Abstract

The aim of this study was to evaluate the associations between head posture (head extension, normal head posture, and head flexion) and anteroposterior head position, hyoid bone position, and the sternocleidomastoid integrated electromyographic (IEMG) activity in a sample of young adults. The study included 50 individuals with natural dentition and bilateral molar support. A lateral craniocervical radiograph was taken for each subject and a cephalometric analysis was performed. Head posture was measured by means of the craniovertebral angle formed by the MacGregor plane and the odontoid plane. According to the value of this angle, the sample was divided into the following three groups: head extension (less than 95 degrees); normal head posture (between 95 degrees and 106 degrees); and head flexion (more than 106 degrees). The following cephalometric measurements were taken to compare the three groups: anteroposterior head position (true vertical plane/pterygoid distance), anteroposterior hyoid bone position (true vertical plane-Ha distance), vertical hyoid bone position (H-H' distance in the hyoid triangle), and CO-C2 distance. In the three groups, IEMG recordings at rest and during swallowing of saliva and maximal voluntary clenching were performed by placing bipolar surface electrodes on the right and left sternocleidomastoid muscles. In addition, the condition with/without craniomandibular dysfunction (CMD) in each group was also assessed. Head posture showed no significant association with anteroposterior head position, anteroposterior hyoid bone position, vertical hyoid bone position, or sternocleidomastoid IEMG activity. There was no association to head posture with/without the condition of CMD. Clinical relevance of the results is discussed.

Ação De Músculos Hióideos Durante Movimentos Da Cabeça Avaliados Pela Eletromiografia

“…Não foram encontradas associações entre posturas de cabeça anteroposteriores e ativação maior de musculatura supra-hióidea, ou seja, posturas do osso hióide no sentido anteroposterior, de acordo com [2].…”

“…A postura da cabeça é um fator significativo nos estudos de movimentos do osso hióide e da função dos músculos supra e infra-hióideos [1] [2].…”

Kraniyofasiyal Morfoloji, Baş Postürü ve Hyoid Kemik Pozisyonu

“…Most of the studies about hyoid bone position have shown that changes in mandibular position are related to hyoid bone changes and that hyoid bone position adapts to anteroposterior changes in head posture (8,9,10 Hyoid kemik mandibulaya geniohyoid, anterior digastrik ve milohyoid kaslar aracılığıylabağlıolduğundan,mandibulanın konumunu değiştiren tüm ortodontik işlemlerin hyoid kemiğin pozisyonunda da değişimlerenedenolabileceğibirçokçalışma ilegösterilmiştir (8,9,10).…”

“…Becausethehyoidboneisattachedtothe mandibula by geniohyoid, anterior digastric andmylohyoidmuscles,ithasbeenshownby severalstudiesthatallorthodonticprocesses those change the position of the mandibula mayalsocausechangesinthepositionofthe hyoidbone (8,9,10).…”

Occlusion and posture: facts and beliefs

“…-the neuromuscular activity of neck and face muscles seems to influence corporal or bodily posture according to many studies 25,65,66,84 , but, according to another one, do not 99 ;…”