Jaw mechanics and muscle behavior in adolescents with different craniofacial morphologies

Jaw mechanics and muscle behavior were evaluated in ten dolichofacial versus ten brachyfacial adolescents. Subjects consented to participate. Numerical modeling predicted TMJ loads for molar biting angles based on minimization of muscle effort and subjects' anatomical geometries (from cephalograms and jaw-tracking). Joint loads were compared via response surface regressions and F tests (α=0.05) determined between-group differences. Surface masseter and anterior temporalis electromyography were recorded, unilaterally over two days and nights and bilaterally at two laboratory sessions when subjects did biting tasks to calibrate field recordings. Muscle duty factors were calculated for magnitude (%electromyography/20N bite) and duration thresholds and between-group differences evaluated using repeated measures ANOVA and Tukey-Kramer post hoc tests. Ipsilateral TMJ loads were 9% or larger in dolichofacial than brachyfacial subjects about seventeen-fold more frequently. Masseter muscles were significantly more active in dolichofacial compared to brachyfacial subjects by three-fold at thresholds of 5% (P<0.01) and 10% (P<0.05). This abstract of 148 words is approved as to form and content.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Oral Biology (UMKC)

Grantor dc:publisher

University of Missouri--Kansas City

Year dc:date.issued

2012

Author dc:creator

• Williams, Ashlee L.

Advisor dc:contributor.advisor

• Iwasaki, Laura

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10355/16208

OAI identifier oai:identifier

oai:mospace.umsystem.edu:10355/16208