ObjectiveTo discuss the fixed restoration for severe dental attrition with partial dentition defect. MethodsWe selected 15 patients who had received treatments in Hebei Ophthalmology Hospital due to dental allergy, chewing weakness and temporomandibular joint dysfuction caused by severe attrition from February 2007 to October 2012. Among them, there were 9 males and 6 females, aged from 22 to 58 years old averaging 33. We performed occlusal reconstruction by fixed restoration for these patients, recovered their vertical dimension, and then carried out the follow-up. ResultsIn the two-year follow-up, two patients had porcelain cracking, one patient's metal-ceramic crown dropped; no gingiva swelling occurred, periodontal tissues were healthy, occlusal functions recovered well, temporomandibular joint dysfunction and masticatory muscles were not discomfortable, subfacial 1/3 was normal, and patients were satisfied with their appearance and facial contour. ConclusionUsing the fixed restoration to reconstruct occlusions can effectively recover patients' masticatory functions, add height for subfacial 1/3, and improve the symptoms of temporomandibular joint.
Masticatory robots have a broad application prospect in the field of denture material tests and mandible rehabilitation. Mechanism type of temporomandibular joint structure is an important factor influencing the performance of the masticatory robot. In view of the wide application of elastic components in the field of the biomimetic robot, an elastic component was adopted to simulate the buffering characteristics of the temporomandibular joint disc and formed the elastic temporomandibular joint structure on the basis of point-contact high pair. Secondly, the influences of the elastic temporomandibular joint structure (on mechanism degree, kinematics, dynamics, etc.) were discussed. The position and velocity of the temporomandibular joint were analyzed based on geometric constraints of the joint surface, and the dynamic analysis based on the Lagrange equation was carried out. Finally, the influence of the preload and stiffness of the elastic component was analyzed by the response surface method. The results showed that the elastic temporomandibular joint structure could effectively guarantee the flexible movement and stable force of the joint. The elastic joint structure proposed in this paper further improves the biomimetic behavior of masticatory robots. It provides new ideas for the biomimetic design of viscoelastic joint discs.