[Stress distribution of mandible under different loading and biting condition].
OBJECTIVE
To study the stress distribution of intact mandible, especially that of the mandibular angle under different muscle loading and biting condition.


METHODS
Develop a more accurate, more objective mandibular model, measure the different stress patterns on the outer surface of the mandible by strain gauges due to different biting sites (INC and ICP) and different loading methods (masseter, temporalis and four pairs of muscles).


RESULTS
It was found that the strain in the zone of mandibular angle is more markedly under masseter loading; that the strain in the zone of anterior mandibular ramus is more markedly under temporalis loading; and that the stress in the zone of mentum becomes a tension because of the medial pterygoid under the load of four pairs of muscles. During anterior teeth biting, the stress of mandible angle is larger than that of the bilateral molar biting. When an occlusal load is on the ipsilateral molars, there is a reversal result of the stress direction in the upper line of the mandibular angle.


CONCLUSIONS
Different muscular loading and biting condition can change the stress distribution of the mandible. It is important to develop a functional model of human mandible to study its complex biomechanics behavior.
Department of Oral and Maxillofacial Surgery, West China School of Stomatology, Sichuan University, Chengdu 610041, China.
Hang
H
Wang
Meng-shi
MS
Chen
Wei-dong
WD
Tian
Sheng-wei
SW
Li
D000328:Adult; D001696:Biomechanical Phenomena; D001732:Bite Force; D003766:Dental Occlusion; D003799:Dental Stress Analysis; D006801:Humans; D007575:Jaw, Edentulous; D008334:Mandible / Q000502:physiology*; D008410:Masticatory Muscles / Q000502:physiology*; D008954:Models, Biological; D013314:Stress, Mechanical; D016474:Weight-Bearing / Q000502:physiology