Evaluation of Stresses on Temporomandibular Joint in the Use of Class II and III Orthodontic Elastics: A Three-Dimensional Finite Element Study.

PURPOSE: The purpose of the present study was to evaluate the effects of the orthodontic elastic forces used in fixed orthodontic treatment on the temporomandibular joint (TMJ) with normal and anteriorly displaced discs. MATERIALS AND METHODS: Four different computer models for Class II and III malocclusion with the TMJ disc in the normal and anterior position were created. All the models were subjected to a constant force of 200g (125 N) on both sides to simulate the elastic pull force placed between the upper and lower jaw with 2 different configurations. Stresses on the TMJ were evaluated using finite element analysis. RESULTS: The stresses in both the condyle and the disc were greater in the Class II models than in the Class III models. Similar results were found between the groups according to the direction of the orthodontic elastics. In the Class II models, the peak value of the maximum principal stresses was located in the posterior region of the condyle in the models with disc in the normal position. CONCLUSIONS: The elastic forces used during fixed orthodontic treatment increases the stress on the TMJ, especially for Class II patients. If the disc is in an anterior position, the stresses could be more harmful to the retrodiscal tissue. Thus, during orthodontic treatment, the TMJ should be carefully assessed to avoid irreversible damage.

Isolated Actinomycosis of the Hard Palate Incurred Subsequent to Local Anesthesia.

Tissue necrosis associated with local anesthesia and actinomycosis is rare. Here, the authors present management of excessive palatal necrosis associated with local anesthesia and actinomycotic infection. In oral surgery a simple procedure can lead to severe complications. Thus, preformation of any surgical procedure with a rigorous manner preferably by a qualified clinician may prevent the occurrence of this type of complications.

Clinical and intra-operative factors affecting the outcome of arthrocentesis in disc displacement without reduction: A retrospective study.

BACKGROUND: Temporomandibular disorder (TMD) is a group of disease which affects the temporomandibular joint (TMJ) and supporting tissues of the musculoskeletal structures. Arthrocentesis is an effective treatment modality for TMD, especially in patients who suffer from pain and limited mouth opening. OBJECTIVE: The aim of this study was to investigate the effects of pre-operative and intra-operative variables on the clinical outcome of arthrocentesis therapy. METHODS: The records of 83 patients diagnosed as disc displacement (DD) without reduction according to DC/TMD, and treated with arthrocentesis were selected. Sex, age, bruxism history, pain intensity and maximum mouth opening (MMO) were recorded as pre-operative variables. Extravasation and the amount of irrigation were recorded as intra-operative variables. The success of the arthrocentesis procedure was determined as MMO <35 mm and pain intensity lower than 3, at third-month follow-up. RESULTS: At 3-month follow-up, clinical evaluation showed a significant reduction in TMJ pain and an increase in MMO (P < 0.05). It was found that patients with an unsuccessful outcome are those who had a more restricted MMO and severe pain before the procedure. Extravasation was found to be a significant factor that affects the success of the procedure. CONCLUSION: The success of arthrocentesis in TMJ DD without reduction is adversely affected by the severity of the pre-operative clinical symptoms. Extravasation is also a factor that has a negative effect on the success of the procedure.

Retrieval of an Unusually Displaced Implant With Healing Cap Into the Mandibular Canal.

Accidental displacement of dental implants into the anatomical spaces is a rare complication that may be accompanied by tissue damage, functional disturbance, psychological distress, and medicolegal conditions. The aim of this report is to present an unusual case of a dental implant that displaced into the mandibular canal and to highlight the importance of adequate preoperative planning and surgical knowledge.

The Effect of Exercise on Range of Movement and Pain After Temporomandibular Joint Arthrocentesis.

PURPOSE: Arthrocentesis is an effective treatment modality for temporomandibular disorders, especially in patients who have pain and limited mouth opening. Surgeons generally suggest physical exercises after arthrocentesis and arthroscopy procedures; however, there has been no study in the literature evaluating the effects of exercise on clinical outcomes. This study investigated whether physical exercises after arthrocentesis would result in early improvements in clinical symptoms in patients with temporomandibular joint disc displacement without reduction (TMJ DDw/oR). MATERIALS AND METHODS: The study group was composed of 27 patients with TMJ DDw/oR. Patients who needed arthrocentesis after failed conservative nonsurgical treatment were enrolled in the study. Group 1 was composed of 14 patients who were not started on a physiotherapy program after the arthrocentesis procedure. Group 2 was composed of 13 patients who were started on a self-administered physiotherapy program immediately after the arthrocentesis procedure. Physiotherapy included a 6-week exercise program. Patients were followed for 3 months. Range of maximal mouth opening (MMO) and joint pain as measured by the visual analog scale (VAS) were examined to determine clinical efficacy before and after treatment. RESULTS: In groups 1 and 2, mouth opening increased and pain scores decreased at 1-week and 1- and 3-month follow-ups (P < .05). No relevant relation was found between the 2 groups according to MMO for all time points and VAS scores at 1 week. A relevant relation was found between the 2 groups according to VAS scores at 1 and 3 months. CONCLUSION: Physical exercise after arthrocentesis has no effect on range of mouth opening but does decrease pain.