Association of masseter muscles thickness and facial morphology with facial expressions in children

Abstract

Objective: To evaluate the potential influence of muscular capacity and facial morphology on facial expressions in children. Materials and methods:A cross-sectional study was carried out on 40 healthy children (ages 9-13), without previous orthodontic treatment. Masseter muscle thickness and anthropometric facial proportions were measured using ultrasound and digital calipers respectively. A three-dimensional infrared face-tracking system was used to register facial expressions. The maximal amplitude of smile and lip pucker (representing maximal lateral and medial commissure movement) were used for analysis. Stepwise regression was used to investigate whether muscle thickness or anthropometric facial proportions were associated with the quantity of commissure movement.Results: When performing maximal smile, children with thicker masseter muscles were found to have more limited displacement of the commissures (R = 0.39; p = 0.036). When performing lip pucker, children with thicker masseter muscles were found to have greater commissure movement (R = 0.40; p = 0.030). No significant associations were found between anthropometric facial proportions and facial expressions. Conclusion:Masseter muscle thickness seems to be associated with facial expressions in children. Those with thicker muscles show more limited commissure movement when smiling, but greater movement with lip pucker. This indicates that masticatory muscles may serve as a surrogate for mimic muscle activity. Facial morphology of the subjects does not seem to be associated with facial expression.

Immunolocalization of neurokinin 1 receptor in WHO grade 4 astrocytomas, oral squamous cell and urothelial carcinoma

“…It also regulates a variety of biological processes after binding to NK-1R [16] such as cardiac conduction system [26], respiratory physiology [47], immune system regulation [33], sensory perceptions [24], pain processing [25] and inflammation [42]. Enhanced expression of SP/NK-1R has been reported in several pathological entities such as breast cancers [30], ovarian cancers [45], oral squamous cell [15,32], pancreatic cancers [12] and thyroid cancers [20].…”