Stress change on the temporomandibular joint in mandibular prognathism subjects with asymmetry after orthognathic surgery

  • Ueki K
  • Nakagawa K
  • Marukawa K
 et al. 
  • 30

    Readers

    Mendeley users who have this article in their library.
  • 8

    Citations

    Citations of this article.

Abstract

The purpose of this study was to evaluate changes in stress on the temporomandibular joint (TMJ) in 80 Japanese subjects (21 males and 59 females, mean age 23.7 years) with mandibular prognathism, with and without asymmetry after orthognathic surgery using the rigid bodies spring model (RBSM). The asymmetric group consisted of 40 subjects whose Mx-Md midline was more than 3 degrees. The remaining 40 subjects formed the symmetric group. The geometry of the stress analysis model was based on frontal cephalograms of the subjects. Menton (Me), the centre point of occlusal force on a line connecting the bilateral buccal cusps of the second molars, and the most lateral, superior, and medial points on the condyle were plotted on a computer display and stress on the condyle was calculated with the two-dimensional RBSM program, Fortran. The degree (force partition) of the resultant force, the direction (angulation), and the displacement (X, Y) of each condyle were calculated and the horizontal displacement (u), the vertical displacement (v), and rotation displacement (theta) of the mandibular body at Me were calculated pre- and post-operatively. The data was analysed using paired and unpaired t-tests. For the vertical (v) and rotational (theta) displacement, the post-operative value was smaller than the pre-operative value (v: P < 0.001, theta: P = 0.0063) in the asymmetric group. For angulation and the X-component, the post-operative value was smaller than that pre-operatively on the deviated (angulation: P = 0.0074, X-component: P = 0.0003) and non-deviated (angulation: P = 0.0024, X-component: P = 0.001) side in the asymmetric group. However, there was no significant difference between the pre- and post-operative value for any parameter in the symmetric group. These findings suggest that surgical correction of mandibular prognathism, with and without asymmetry, could induce an improvement in stress balance on the TMJ in the frontal aspect.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Authors

  • Koichiro Ueki

  • Kiyomasa Nakagawa

  • Kohei Marukawa

  • Etsuhide Yamamoto

  • Norio Takeuchi

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free