Three-dimensional evaluation of mandibular deformation during mouth opening

Wolf L, Bergauer B, Adler W, Wichmann M, Matta RE (2019)


Publication Type: Journal article

Publication year: 2019

Journal

Book Volume: 22

Pages Range: 21-27

Journal Issue: 1

Abstract

Aim: Deformation of the mandible presents a major challenge for many dentists, both in conventional prosthetic supraconstructions and in complex implant restorations. This study aimed to evaluate the three-dimensional (3D) deformation of the mandible in vivo with scannable impression material and an industrial optical scanner. Materials and methods: In the present study, 20 female and 20 male subjects were examined. In each case, two impressions were made with polyvinylsiloxane: one with the mouth slightly open, and a second with the mouth wide open. The impressions were digitized with an industrial optical scanner and transformed into a virtual model. The two corresponding models were digitally superimposed over all the teeth. Then, an individual local coordinate system was assigned to each individual tooth. Subsequently, a best-fit procedure was performed for each individual tooth. Finally, the open- and closed-mouth models were compared by calculating the differences and rotations in the individual axes. This procedure was performed individually for each tooth. Results: The mean deviations in the x-, y-, and z-coordinates ranged from 0.011 mm at the canines to 0.232 mm at the molars. Larger discrepancies were observed in the female subjects than in the male subjects; however, these differences were not statistically significant. Conclusion: The results demonstrated that the posterior region of the mandible deformed when the mouth was maintained in a wide-open position. Therefore, this position should be avoided when performing dental impressions. Moreover, potential negative consequences of this mandibular deformation should be taken into consideration when planning wide-span fixed dental restorations.

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How to cite

APA:

Wolf, L., Bergauer, B., Adler, W., Wichmann, M., & Matta, R.E. (2019). Three-dimensional evaluation of mandibular deformation during mouth opening. International Journal of Computerized Dentistry, 22(1), 21-27.

MLA:

Wolf, Linda, et al. "Three-dimensional evaluation of mandibular deformation during mouth opening." International Journal of Computerized Dentistry 22.1 (2019): 21-27.

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