Changes in occlusal force depending on the movement of the adjacent and opposing teeth after loss of lower first molar: comparative study by using a strain gauge.
10.14368/jdras.2016.32.1.47
- Author:
Myoung Ja SONG
1
;
Ji Man PARK
;
Youn Sic CHUN
Author Information
1. Department of Orthodontics, Graduate School of Clinical Dentistry, Ewha Womans University, Seoul, Republic of Korea. yschun1000@gmail.com
- Publication Type:Comparative Study ; Original Article
- Keywords:
loss of lower molar;
tilted adjacent tooth;
occlusal force;
strain gauge
- MeSH:
Bicuspid;
Bite Force*;
Dental Arch;
Mastication;
Molar*;
Periodontal Ligament;
Silicon;
Silicones;
Tooth*
- From:Journal of Dental Rehabilitation and Applied Science
2016;32(1):47-59
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
PURPOSE: The aim of this study was to investigate the changes in occlusal force after loss of the lower first molar depending on the inclination and extrusion of the adjacent and opposing teeth by using a strain gauge. MATERIALS AND METHODS: Anatomic teeth were used to reconstruct the normal dental arch with loss of the lower right first molar. A uniformly thick layer of silicone was applied to the root to mimic the periodontal ligament. Four stages of dies with varying degrees of inclination and extrusion of the adjacent and opposing teeth were constructed and attached to master model interchangeably by using a CAD/CAM fabricated customized die system. The strain gauges were attached to teeth and a universal testing machine was used to determine the changes in occlusal force. An independent t-test and one-way ANOVA were performed (α = .05). RESULTS: While simulating chewing food, the upper first, second premolar and lower second molar showed greater occlusal force than before extraction. When the change of adjacent teeth's occlusal force with their progressive movement after molar loss was evaluated, the difference among four die models was significant and was in the decreasing aspect (P < 0.05). CONCLUSION: When the lower first molar was lost and the adjacent teeth did not move yet, the occlusal force in adjacent teeth was higher than that when the lower first molar still existed. In addition, the occlusal force in the upper premolars and lower second molar decreased significantly with the progressive movement of adjacent teeth.
