Medication-related osteonecrosis of the jaw: Evidence for infection versus oversuppression

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Background: Antiresorptive medications are important in maintaining bone health for patients with osteoporosis, metastatic cancer and multiple myeloma. Medication-related osteonecrosis of the jaw (MRONJ) may compromise quality of life and treatment of the underlying disease. There are many controversies regarding the pathogenesis, risk and management of MRONJ. Evidence-based data that suggest osteonecrosis of the jaw (ONJ) is triggered by infection and reports of ONJ unrelated to antiresorptive therapy (ART) have confounded previous hypotheses that pathogenesis is directly attributed to ART by oversuppression of bone remodeling. The aim of this study is to determine the outcome for management of MRONJ based on eradication of infection. Methods: The investigators designed a retrospective cohort study for patients who underwent surgical management of MRONJ. Identification of infected and necrotic bone was achieved via nuclear imaging (i.e., technetium bone scan, positron emission tomography), computed tomography and/or cone beam computed tomography. Surgical techniques included bone resection (i.e., marginal, segmental), local flap, reconstruction with microvascular free flap, and/or autogenous platelet graft. Perioperative modalities included hyperbaric oxygen therapy and culture-guided antibiotic administration. We recorded medical history, location of the MRONJ lesion, type of antiresorptive therapy and duration of perioperative antiresorptive therapy. The outcome variable was postoperative healing defined by mucosal closure without signs of infection or exposed bone at the time of follow-up including cases with complications related to subsequent dental infection or treatment. Descriptive statistics were calculated for successful management, medical history and duration of perioperative antiresorptive therapy. We excluded cases treated by palliative intent, when surgery was limited or contraindicated, and/or inadequate follow-up. Results: A total of 54 patients with 59 MRONJ lesions were evaluated (40 with cancer and 14 with osteoporosis). All patients were successfully treated with 13 patients continuing ART after surgery (average follow-up 10 months) and 8 patients requiring more than 1 surgery for lesions associated with osteosclerosis. Conclusions: This study suggests that MRONJ is an infection-driven process that can be managed with various modalities to control diseased bone and facilitate healing. Patients may resume ART following successful management of MRONJ.

Dynamic sagittal half-Fourier acquired single-shot turbo spin-echo MR imaging of the temporomandibular joint: initial experience and comparison with sagittal oblique proton-attenuation images

BACKGROUND AND PURPOSE

Our aim was to assess dynamic half-Fourier acquired single-shot turbo spin-echo (HASTE) MR imaging of the temporomandibular joint (TMJ) using parallel imaging, in comparison with static proton density (Pd) imaging.

MATERIALS AND METHODS

Thirty-four TMJs from 17 subjects (7 volunteers, 10 patients) were imaged in a multichannel head coil on a 1.5 T magnet by using a 35-second dynamic sagittal HASTE acquisition (TR/TE, 1180/65 msec; matrix, 128 x 128; section thickness, 7 mm; 30 images) and sagittal oblique Pd in closed- and open-mouthed positions (TR/TE, 1800/12 msec; matrix, 256 x 256; section thickness, 2 mm; 15 sections). Images were reviewed by 3 readers and rated for confidence of disk position, presence of motion artifact, range of motion, and presence of disk displacement on a 5-point scale. Consensus review of cases was also performed to assess disk dislocation and limited range of motion.

RESULTS

More static examinations were rated as having motion artifact (19.6% versus 6.9%, P=.016), limited range of motion (30.4% versus 17.7%, P=.016), and disk dislocations (31.4% versus 22.6%, P=.071). Confidence ratings were higher on dynamic examinations (4.11 versus 3.74, P=.018). Chi-squared tests demonstrated no significant difference in consensus reviews of the 2 examination types.

CONCLUSION

Dynamic HASTE TMJ MR imaging is a time-efficient adjunct to standard MR imaging protocols, producing fewer motion artifacts, additional range of motion information, and a dynamic assessment of disk position, when compared with static imaging. Further study is needed to evaluate the role of this sequence in diagnosing disk displacement.