Discectomy as the primary surgical option for internal derangement of the temporomandibular joint.

PURPOSE: The goal of this study was to evaluate outcomes of patients who underwent temporomandibular joint (TMJ) discectomy without replacement as the primary treatment for internal derangement after failure of nonsurgical therapy. PATIENTS AND METHODS: Thirty consecutive patients with TMJ internal derangement were treated with discectomy from 2001 to 2007. Four patients were lost to follow-up, and 2 were excluded because of prior joint surgery. Using the standardized Helkimo Anamnestic and Clinical Dysfunction Indexes, 24 patients, or 32 joint surgeries, were evaluated postoperatively, with an average follow-up of 30.8 months (range, 2 to 60 months). RESULTS: All 24 patients showed improvement in mandibular mobility and joint function, as well as reduction in TMJ and muscular facial pain, represented by a clinical dysfunction index of DiO, DiI, or DiII. Preoperatively, all patients had an anamnestic index of AiII, which represented moderate to severe pain in the TMJ and masticatory muscles, and/or locking of the joint before surgery. Postsurgically, 20 of the 24 patients scored an index of DiO or DiI, which correlated with a clinically symptom-free state or only a small, minor dysfunction. TMJ pain, muscle pain, and pain with mobility scored the lowest point index, indicating a subjectively successful outcome. CONCLUSIONS: Discectomy of the TMJ as a primary surgical option significantly reduces pain and improves function.

Evaluation of bone thickness in the anterior hard palate relative to midsagittal orthodontic implants.

PURPOSE: The Straumann Orthosystem (Institut Straumann, Waldenburg, Switzerland) describes a technique that involves placement of titanium implants (4 or 6 mm long and 3.3 mm in diameter) into the midsagittal hard palate for orthodontic anchorage. The aim of this study was to determine the quantity of bone in the midline of the anterior hard palate, and specifically the thickness inferior to the incisive canal. MATERIALS AND METHODS: Twenty-five dry skulls were radiographed with a standardized cephalometric technique. The vertical thickness of the midsagittal palate was then measured to the nearest tenth of a millimeter. Next, gutta-percha was injected into the incisive canal, and the radiograph was repeated. The bone thicknesses were then measured from the inferior hard palate to the most Inferior part of the radiopaque canal. This is defined as the actual bone available for the implant without violating the canal. RESULTS: The measurements have shown that an average of 8.6 +/- 1.3 mm of bone is theoretically available for the implant. However, considering the canal (where only bone thickness inferior to it is utilized and measured), only 4.3 +/- 1.6 mm of bone exists. The canal itself averaged 2.5 +/- 0.6 mm in diameter. DISCUSSION: Prior studies have overestimated the amount of bone available for implants in the median hard palate. The main reason for this is that the incisive canal is not well visualized on cephalometric radiographs of live patients. CONCLUSION: This study supports the continued use of implants, as approximately 50% of skulls still had the requisite minimum 4 mm of bone inferior to the incisive canal for maximum osseointegration with the 4-mm implants. However, 6-mm implants should be used with caution.