What is the best position for palatal implants? A CBCT study on bone volume in the growing maxilla.

OBJECTIVE: The objectives of the present study are the following: (a) to investigate limitations (bone height, proximity to nasopalatine nerve and roots) in juvenile patients, (b) to review the recommended site for surgical insertion (level of the maxillary first premolars), and (c) to reassess the rationale behind the manufacturer's age limitation (12 years). PATIENTS AND METHODS: Cone beam CT images of 100 patients aged 10 to 20 years were analyzed. Vertical bone heights were measured in the median plane as well as 3- and 6-mm paramedian along the prospective axis of insertion, at the level of the first premolars (level 0), 3 mm anterior (level 1) and 3 mm posterior (level 2). The Mann-Whitney U test was used to compare bone heights between gender groups. RESULTS: The risk of damage to the nasopalatine nerve is highest in the median region on level 1 (46 %). The risk was lowest in the midsagittal region on level 0 (recommended insertion site; 3 %) and level 2 (0 %), as well as paramedian on levels 0 and 2. The risk of damaging roots was irrelevant for median insertion at all levels; the only critical region was 6-mm paramedian on level 1. CONCLUSIONS: The recommendation of surgical insertion at the level of the maxillary first premolars is still justified, but a slightly more posterior implant position might improve safety. We found no relevant growth-related changes in the vertical bone heights in the median palatal area. Thus, our data do not support the strict 12-year age restriction for palatal implants.

Osteonecrosis of the mandible due to anti-angiogenic agent, bevacizumab.

BACKGROUND: Osteonecrosis of the jaw (ONJ) is defined by areas of tissue breakdown and exposure of bone in the maxillofacial region that fail to heal within 8 weeks after identification by a health provider in a patient who has not received radiation of the jaws. The disease affects the quality of life and produces significant morbidity in afflicted patients. ONJ is correlated with such risk factors as treatment with bisphosphonates, dental extraction-related trauma, chemotherapy, corticosteroids, renal osteodystrophy and infections. Although the use of bisphosphonates is associated with osteonecrosis of the jaw, the pathophysiology of bisphosphonate-associated ONJ is still unknown. It has been assumed that bisphosphonates lead to the inhibition of capillary angiogenesis and disturbances in the activities of both osteoblasts and osteoclasts, thereby impairing bone remodelling. Currently, inhibitors of angiogenesis used in the treatment of cancer patients are implicated in isolated cases of ONJ. CASE REPORT: This manuscript reports a case of ONJ in a female patient who received bevacizumab (Avastin®, Roche), a humanised monoclonal antibody that recognises and blocks vascular endothelial growth factor (VEGF)-A. CONCLUSION: The anti-angiogenic agent, bevacizumab, may increase the risk of osteonecrosis of the jaw. This agent inhibits VEGF and, therefore, also presumably represses the vascularisation of the jaw, which leads to healing complications. Due to increasing use of bevacizumab, patients receiving this agent should be closely monitored for possible side effects.