Removal of a Frontal Sinus Osteoma and Reconstruction by a Custom-Made Implant with Neuronavigation Assistance.

The authors report the surgical treatment of an extensive right frontal sinus osteoma assisted by neuronavigation and reconstruction by a hydroxyapatite custom-made implant. The patient presents with ptosis, hypoglobus, and proptosis of the right eye, without any visual impairment. Computed tomographic (CT) scan showed a very large bony mass involving right frontal sinus and displacing the orbital roof. A stereolithographic model-guided planning was carried out to obtain a practical simulation of the surgical operation and it was submitted to a new CT scan to acquire the reference point to realize the neuronavigation assistance, and to achieve the template to realize the hydroxyapatite custom-made implant. Intraoperatively, with the help of neuronavigation assistance, osteotomies were performed by piezoelectric device. The reconstruction was made using a hydroxyapatite custom-made implant. The procedure was damage free, the bony mass was excised, and the orbital roof was repaired without any adverse effects. Postsurgical CT scan and scintigraphy showed a good reconstruction and a good-quality osteoblasts activity on the borders of the implant. Osteoma is a benign slow-growing bone tumor, usually involving the frontal sinus. Navigational assistance offers a very important help to perform safe osteotomies. Hydroxyapatite custom-made implant seems to be an excellent reconstructive method.

Osteomalacia: the missing link in the pathogenesis of bisphosphonate-related osteonecrosis of the jaws?

BACKGROUND: Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a well-documented adverse event from treatment with nitrogen-containing bisphosphonates (NBPs). During a preliminary histomorphometric study aimed at assessing the rate of bone remodeling in the jaws of patients with surgically resected BRONJ, we found a defect of bone mineralization (unpublished data). We hypothesized that osteomalacia could be a risk factor for BRONJ in patients taking NBPs. Therefore, we looked for static and dynamic histomorphometric evidence of osteomalacia in biopsies from subjects with and without BRONJ. METHODS: This case-control study used histomorphometric analysis of bone specimens of patients using NBPs (22 patients with BRONJ and 21 patients without BRONJ) who required oral surgical interventions for the treatment/prevention of osteonecrosis. Patients were given tetracycline hydrochloride according to a standardized protocol before taking bone biopsies from their jaws. Biopsies with evidence of osteomyelitis or necrosis at histology were excluded from the study. Osteomalacia was defined as a mineralization lag time >100 days, a corrected mean osteoid thickness >12.5 mm, and an osteoid volume >10%. RESULTS: In all, 77% of patients with BRONJ were osteomalacic compared with 5% of patients without BRONJ, according to histomorphometry. Because osteomalacia was found almost exclusively in NBP users with BRONJ, this is likely to be a generalized process in which the use of NBPs further deteriorates mechanisms of bone repair. CONCLUSIONS: Osteomalacia represents a new and previously unreported risk factor for disease development. This finding may contribute to a better understanding of the pathogenesis of this disease and help with the development of strategies to increase the safety of NBP administration.

Long-term outcomes of surgical resection of the jaws in cancer patients with bisphosphonate-related osteonecrosis.

Surgical treatment of bisphosphonate-related osteonecrosis of the jaw (BRONJ) is controversial. Current recommendations contraindicate aggressive surgery because its results are unpredictable and may trigger disease progression. In this prospective study, we assessed the effectiveness of surgical resection of the jaws in cancer patients with BRONJ. Between June 2004 and July 2009, 30 cancer patients with refractory BRONJ underwent surgical resection of the jaws at our Units. They were followed-up weekly for the first month, at 3-month intervals up to 1 year, and at 6-month intervals up to 2 years. Panoramic radiographs and CT-scan were obtained at 3, 6, 12, 18 and 24 months. Primary outcomes were the 24-month recurrence rate of BRONJ and the 24-month mortality rate. Secondary outcomes were post-operative complications, duration of hospital stay after surgery, time to return to oral diet, and degree of oral pain. The 30 patients had a median age of 66 years and were mostly females (80%). Twenty-eight underwent a single resection and two had both jaws resected, for a total of 32 resected jaws. The cumulative recurrence rate of BRONJ in resected jaws 3.1% and 9.4% at 3 and 6 months, respectively. All the jaws with recurrent BRONJ had osteomyelitis at the margins of bone resection. The cumulative incidence of death was 3%, 12% and 16% at 12, 18 and 24 months. Surgical resection of BRONJ was highly effective, with few post-operative complications and were not associated with long-term mortality.

Occurrence of bisphosphonate-related osteonecrosis of the jaw after surgical tooth extraction.

PURPOSE: To evaluate the occurrence of bisphosphonate-related osteonecrosis of the jaw (BRONJ) in patients exposed to nitrogen-containing bisphosphonates (NBPs) requiring surgical tooth extraction. PATIENTS AND METHODS: Sixty high-risk patients exposed to NBPs underwent surgical tooth extraction with bone biopsy and were treated with a 7-day cycle of oral antibiotics and discontinuation of NBPs for 1 month. BRONJ was defined as the occurrence of any BRONJ stage (0-3) at 3, 6, or 12 months of follow-up. Inferential analysis was performed on a per-bone (maxilla and/or mandible) basis (n = 72). The time to BRONJ was calculated, and age, gender, cancer diagnosis, and baseline osteomyelitis were evaluated as potential predictors. Exact logistic regression was used to model the time-to-outcome relationship, and hazard rates were calculated from logistic probabilities. RESULTS: BRONJ was detected at 3 months' follow-up in 4 bones and at 6 months in 1 further bone. In the whole cohort of bones, the hazard rate of BRONJ was 5.6% at 3 months and 1.5% at 6 months. Baseline osteomyelitis was a strong risk factor for BRONJ development (odds ratio, 156.96; exact 95% confidence interval, 18.99 to infinity; exact P < .0001). CONCLUSION: In this 12-month follow-up study, BRONJ was a rare outcome in high-risk NBP users who underwent surgical tooth extraction. Moreover, baseline osteomyelitis was a very strong risk factor for BRONJ development.