Oral Maxillofacial Surgery

Wallace S, Gellin R. “Clinical evaluation of freeze-dried cancellous block allografts for ridge augmentation and implant placement in the maxilla” Implant Dent, 19(4):272-9, 2010

A number of grafting materials have been used in vertical and horizontal ridge augmentation to enable implant placement in optimal positions. Autogenous block grafts from intraoral or extraoral sites have been used with positive results. Allograft blocks with cortical bone are also used for ridge augmentation. In this case series, cancellous allograft blocks were used for horizontal augmentation of the maxilla. The observed increase in ridge width allowed subsequent implant placement after a 5-month healing period. Four months after placement, the implants were uncovered and restored. The results suggest that cancellous block allografts may be a viable alternative to autogenous block grafts or cortical allograft blocks in treatment of deficient maxillary alveolar ridges to allow subsequent implant placement in optimal position in the maxilla

Avila-Ortiz G, Wang HL, Galindo-Moreno P, Misch CE, Bagramian RA, Rudek I, Benavides E, Moreno-Riestra I, Braun T, Neiva R.: “The Influence of the Bucco-Palatal Distance on Sinus Augmentation Outcomes.” J Periodontol, 81(7): 1041-50, 2010

Background: Maxillary sinus augmentation has been regarded as one of the most reliable implant site development options to increase vertical bone height. However, graft consolidation requires adequate angiogenesis and migration of cells involved in osteogenesis and bone remodeling. It has been speculated that these biologic events are greatly determined by the dimensions of the maxillary sinus cavity. Hence, the purpose of this study was to assess the influence of the distance from the lateral to the medial wall of the maxillary sinus on the outcomes of sinus augmentation procedures. Methods: A total of 25 patients in need of sinus augmentation were recruited for the study. After initial exam, customized radiographic/surgical guides were fabricated and a cone-beam computerized tomography scan was obtained per patient. The buco-palatal distance (BPD) was measured at 8, 10 and 12 mm from the alveolar crest. Sinus grafting was performed by a lateral window approach using a particulated allograft material. Patients were followed-up for six months. At the time of implant placement, bone core biopsies were harvested using the radiographic/surgical guide. Sections of the bone cores at 8, 10 and 12 mm from the alveolar crest were histomorphometrically analyzed. The proportion of vital bone (%VB) was correlated with the BPD using a statistical model. Results: Twenty-one patients underwent sinus augmentation for a total of 24 sinuses; however, the data analyzed contained only one sinus per patient. One sinus developed an infection after grafting, resulting in a 96% success rate for the sinus grafting procedure. Therefore, 20 sinuses were finally included in the statistical analysis. Histomorphometric analysis revealed that mean % of vital bone was 22.71 +/- 19.08, mean % of remaining allograft was 23.39 +/- 20.85, and average % of non-mineralized connective tissue was 53.90 +/- 13.23. Analysis of the correlation between %VB and BPD via linear regression, using the actual values of BPD, showed a strong negative association (R(2) = 0.141; P <0.001). This finding suggests that as BPD decreases, %VB increases. Conclusion: These findings suggest that the proportion of vital bone formation after maxillary sinus augmentation is inversely proportional to the sinus bucco-palatal distance.

Hunter SA, Orheim R, Sazon M, Newman H, Woll JE, Bergevin M.: “Demineralization Removes Residual Alendronate in Allograft Bone Procured from Donors with a History of Bisphosphonate use.” J Periodontol, 82(2): 281-6, 2011

Background: Bisphosphonate-associated osteonecrosis (BON) of the jaw is a growing concern in the dental community, but the possible presence of residual bisphosphonates in demineralized allograft bone from bisphosphonate-using tissue donors and the clinical implications of using such bone are unclear. The objectives of this study were to determine if alendronate remained in demineralized bone matrix (DBM) procured from donors with a documented history of oral bisphosphonate* use and to examine whether the demineralization process removes alendronate from allograft bone. Methods: A gas chromatography-mass spectrometry (GC-MS) method was developed and validated to quantify residual alendronate in allograft bone. Alendronate levels in DBM procured from tissue donors with a history of oral bisphosphonate use was compared to that from non-bisphosphonate using donors. In addition, both mineralized and demineralized bone was soaked in alendronate at concentrations of 0.002, 2.0, and 2,000 ng/mg of bone and analyzed to examine the effect of the demineralization process. Results: Residual alendronate was not detected in the DBM from both bisphosphonate using and non-using donors. It was also not detected in any of the DBM samples soaked in alendronate solutions. Soaked mineralized bone contained measureable alendronate, but it was removed by demineralization. Conclusions: The demineralization process effectively removes residual alendronate from allograft bone. These results may relieve anxieties regarding the use of DBM in dental patients, as it is unlikely to trigger BON of the jaw.