[Study on masticatory muscles and tooth long axis of miniature pigs].
OBJECTIVE
The similarities of masticatory muscles and teeth orientations between miniature pigs and human beings were studied in order to evaluate the use of miniature pigs in oral biomechanics research.


METHODS
By means of anatomy, the shapes, start-stop points and orientations of muscle of major masticatory muscles of miniature pigs were measured. Inclination of upper and lower teeth long axis was studied with lateral xray film of mandibles.


RESULTS
The main masticatory muscles of miniature pigs include masseter muscle, temptory muscle, lateral pterygoid muscle, medial pterygoid muscle and zygomaticomandibular muscle. The angles of masticatory muscles and base plane are 63.9 degrees in massater muscle, 114.55 degrees in temple muscle, 64.4 degrees in medial pterygoidp muscle. The long axises of miniature pigs teeth are 6.1 degrees in the upper first molar, 6.5 degrees in the lower first molar, 7.3 degrees in the upper third premolar, 3.8 degrees in the lower third premolar.


CONCLUSIONS
The masticatory muscles of miniature pigs are similar with human being in the shape, start-stop point and orientation of muscle force. The third premolar and the first molar of miniature pigs inclinate mesially, and are similar with the first premolar and the first molar of the human beings. Miniature pigs can be used as an animal models which can explain some problems of gnathostomatic system of human beings.
Xu
L
L
School of Stomatology, Beijing Medical University, Beijing 100081.
Xu
J
J
Feng
S
S
D000818:Animals; D008410:Masticatory Muscles / Q000033:anatomy & histology*; D023421:Models, Animal; D008963:Molar / Q000033:anatomy & histology*; D013552:Swine; D013556:Swine, Miniature