Three-dimensional evaluation of mandibular deformation during mouth opening.
Int J Comput Dent
; 22(1): 21-27, 2019.
Article
em En
| MEDLINE
| ID: mdl-30848251
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 ANDMETHODS:
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.Palavras-chave
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Técnica de Moldagem Odontológica
/
Modelos Dentários
Limite:
Female
/
Humans
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article