Study of mandibular movement trace in skeletal anterior reverse bite malocclusion after the early stage orthodontic treatment of mixed dentition
- VernacularTitle:替牙列早期骨性前牙反早期治疗结束后下颌运动轨迹的变化
- Author:
Rui LI
;
Hongchen LIU
- Publication Type:Journal Article
- Keywords:
skeletal anterior reverse bite;
ACRUSdigma system;
early treatment;
opening movement;
protrusion movement
- From:
Medical Journal of Chinese People's Liberation Army
1981;0(06):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To study the differences between the mandibular movement in empty opening and protrusion trace of the skeletal anterior reverse malocclusion before and after the early protraction treatment in early stage of mixed dentition. Methods ACRUSdigma system, a kind of ultrasonic mandibular movement record system, was used in the study. The kinematic center which can represent the translation and rotation of the condylar and the incisal points were used as reference point to compare the difference of the empty opening and protrusion mandibular movement trajectory of 30 individuals with skeletal anterior reverse bite malocclusions before and after the early protraction facemask treatment. Results For the kinematic center, the typical trajectory was changed, the upper movement disappeared and the distances between vertical and horizontal movements were increased at the end of the treatment in the empty opening movement on the sagittal plane. In the empty protrusion movement, the interplanar distance of the kinematic center was increased significantly on the sagittal plane. For the incisial point, it moved ahead at first and then downward vertically in the empty protrusion movement, and the interplanar distance was increased significantly on the sagittal plane in the empty opening movement. Conclusions By giving the protraction treatment, the relation of upper mandible and submaxilla of the skeletal anterior reverse bite malocclusions is changed. During the later stage of the treatment, for the occlusal splint was ground off, the normal occlusial inducement is built, which affords the rebuilding of temporomandibular joint (TMJ), ligaments and muscles. The trajectory also becomes normal. The normal trajectory may supply a better environment for the development and rebuilding of jaw, TMJ, ligaments and muscles.
