Preliminary Investigation of the Biomechanics of Unilateral Chewing Comparing Two Testing Models: In Vitro Study

Abstract

This article reports a preliminary study undertaken to investigate the biomechanics of unilateral chewing due to lateral segmental defects extending to angulus, introducing modified designs of 3-point and 2 point testing models. Data concerning test setups used in biomechanic studies of mandible in the literature have been analysed. Material and Methods: Load/displacement data were gathered for the mandibles with the same defect and reconstructed with reconstruction plate in a standart way. Standard models underwent unilateral loading with two different test set-up. The first set-up was consistent with 3 point testing model (Group I) while the second set-up was simulating 2 point testing model (Group II). Furthermore, literature related with in vitro studies of mandible were searched and testing setups used in these studies were evaluated. Results: The mean displacement for Group I was 12.11 mm (±3.36), Group II was 19.56 (±0.92) mm. Group II had significantly greater (p=0.000) displacement when compared with Group I. The mean force before failure for Group I was 850.3 N (±136.1 N), Group II was 1117.83 N (±107.3 N). Models tested with two point system failed at significantly greater force (p=0.000), Conclusion: Three point testing model was more efficient and reflecting the chewing forces better under unilateral loading. Many biomechanic studies in the literature adopted three point system for their studies.