Evaluation of signs, symptoms, and occlusal factors among patients with temporomandibular disorders according to Helkimo index.

Objective: This study sought to assess the clinical signs and subjective symptoms of TMD, including the occlusal condition. Methods: Recruited individuals included 123 patients (58 men, 65 women) aged 15 to 65 years (mean 38.6 years) who had been referred to the TMD department. Helkimo dysfunction, occlusal, and anamnestic indices were used to assess signs of TMD, occlusal condition, and symptoms, respectively. Relationships of occlusal factors with signs and symptoms of TMD were evaluated by Spearman's correlation test. Associations of TMD with sex and age distributions were assessed by Mann-Whitney and Spearman's test, respectively. Results: The prevalence of signs and symptoms was as high as 75%. Occlusal factors had significant associations with signs and symptoms of TMD. Conclusion: Prevalence of TMD in the study population was high, without preference for age or sex. Occlusal factors may play a role in the etiology of TMD.

Stress distribution pattern of screw-retained restorations with segmented vs. non-segmented abutments: A finite element analysis.

Background. Screw-retained restorations are favored in some clinical situations such as limited inter-occlusal spaces. This study was designed to compare stresses developed in the peri-implant bone in two different types of screw-retained restorations (segmented vs. non-segmented abutment) using a finite element model. Methods. An implant, 4.1 mm in diameter and 10 mm in length, was placed in the first molar site of a mandibular model with 1 mm of cortical bone on the buccal and lingual sides. Segmented and non-segmented screw abutments with their crowns were placed on the simulated implant in each model. After loading (100 N, axial and 45° non-axial), von Mises stress was recorded using ANSYS software, version 12.0.1. Results. The maximum stresses in the non-segmented abutment screw were less than those of segmented abutment (87 vs. 100, and 375 vs. 430 MPa under axial and non-axial loading, respectively). The maximum stresses in the peri-implant bone for the model with segmented abutment were less than those of non-segmented ones (21 vs. 24 MPa, and 31 vs. 126 MPa under vertical and angular loading, respectively). In addition, the micro-strain of peri-implant bone for the segmented abutment restoration was less than that of non-segmented abutment. Conclusion. Under axial and non-axial loadings, non-segmented abutment showed less stress concentration in the screw, while there was less stress and strain in the peri-implant bone in the segmented abutment.