TMJ osteoarthritis in patients submitted to orthognathic surgery: quantitative three-dimensional evaluation of condylar changes and influence of articular disc repositioning

Author(s)

Liliane de Carvalho Rosas Gomes

• Document type: Doctoral Thesis
• Press: Araraquara. 2017-04-11.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Odontologia. Araraquara
• Defense date: 2017-03-10
• Advisor: João Roberto Gonçalves; Lúcia Helena Soares Cevidanes

Abstract

Objectives: The general purpose of this study was to investigate temporomandibular joint (TMJ) osteoarthritis in patients that underwent counterclockwise maxillomandibular advancement surgery, by using new computational techniques developed for optimizing the use of threedimentional images. The specific goals consisted on: quantitatively assessing post-surgical condylar displacemet and remodeling changes, considering differences among three groups (Group 1, condyles from patients submmitted to disc replacement surgery simultaneoustly with the orthognathic surgery; Group 2, condyles from patients that presented with disc displacement but did not undergo disc replacement surgery; Group 3, condyles from patients with healthy TMJ); investigate long-term stability of the surgical procedure; identify possible gender differences considering condylar remodeling in the follow-up period; identify association between clinical and surgical factors with remodeling changes in the mandibular 21 condyles of patients that underwernt disc replacement surgery simultaneously with the orthognathic surgery. Materials and Methods: Three scientific papers were elaborated and used for assessing the purposes presented. Results: On average, after orthognathic surgery it was observed posterior and medial condylar displacement, besides rotations in the three planes of the space. Downward condylar displacement was noticed in Group 1, whereas it moved upward in the other groups (p ≤ 0.001). The overall surgical procedure appeared to be fairly stable, particularly for Groups 1 and 3. Group 2 showed the larger amount and percentage of patients experiencing relapse. Regarding condylar remodeling during the postoperative follow-up period, Group 1 showed significant amount of bone apposition on the anterior pole (p ≤ 0.001). No statistically significant differences were found regarding condylar volume changes between Groups 1 and 3. Larger volume reduction was observed in Group 2 (p ≤ 0.05). Although, on average, female condyles showed greater volume reduction, statistically significant gender differences were not observed. Weak but statistically significant correlation coefficients were observed between some clinical and surgical variables with condylar remodeling changes in the follow-up period. The older the patient, the greater the susceptibility to condylar volume reduction after orthognathic surgery (p ≤ 0.001). Displacement condylar changes generated by counterclockwise maxillomandibular advancement and disc repositioning surgery did not 22 seem to be associated with greater condylar resorption in the follow-up period. Such changes showed, on average, opposite direction from those correlated with greater risk of condylar resorption. Conclusions: Our results suggest that disc replacement surgery is an important ally for counterclockwise maxillomandibular advancement surgery, providing a protective effect to the mandibular condyle affected by TMJ osteoarthritis. (AU)

• FAPESP's process: 13/09986-6 - Temporomandibular joint osteoarthritis. Three-dimensional quantitative assessment of condylar remodeling after maxillomandibular counterclockwise rotation and mandibular advancement surgery
• Grantee: Liliane de Carvalho Rosas Gomes
• Support Opportunities: Scholarships in Brazil - Doctorate