Knowledge, practices, and opinions of ontario dentists when treating patients receiving bisphosphonates.

PURPOSE: Bisphosphonate-related osteonecrosis of the jaws (BRONJ) is a severe but extremely rare complication of prolonged treatment with bisphosphonates (BPs). Improper treatment or misdiagnosis can have serious repercussions. In some cases, the treatment of BRONJ can require jaw resection, prolonged use of antibiotics, and long hospitalizations. This study aimed to measure the awareness of dentists in the Province of Ontario, Canada about BRONJ and to identify any gaps in their knowledge of the condition and its treatment. In particular, the study aimed to answer questions about the dentists' knowledge of the current guidelines and their opinions and practices related to performing surgical dental procedures in patients taking BPs. MATERIALS AND METHODS: The study involved sending a Web-based questionnaire to a random sample of dentists in Ontario, Canada (n = 1,579). Information about their awareness of BPs, their experiences treating patients presenting with ONJ, their experiences with different surgical procedures in patients taking intravenous or oral BPs, and their awareness of the BRONJ guidelines suggested by the American Association of Oral and Maxillofacial Surgeons was collected. RESULTS: A response rate of 30% was achieved. Sixty percent of responding dentists had a good knowledge of BP and BRONJ; however, only 23% followed the guidelines for surgical treatment of a patient taking BPs, and 63% would refer patients if they were taking BPs. Approximately 50% of responding Ontario dentists were not comfortable treating patients with BRONJ at their current knowledge. CONCLUSION: The finding shows that although 60% of Ontario general dentists and specialists have a good knowledge about BRONJ, most are not comfortable performing oral surgery in patients taking BPs. Those who are comfortable have higher knowledge scores, suggesting greater educational efforts should be made to promote the knowledge of dentists regarding BP, ONJ, and BRONJ.

Bone formation in algae-derived and synthetic calcium phosphates with or without poloxamer.

Calcium phosphate ceramics such as hydroxyapatite (HA) and biphasic calcium phosphates are used clinically to repair bone defects. These calcium phosphate ceramics can differ by composition, structure, and rate of degradation. This study compared 3 calcium phosphate ceramics, 2 of which have similar structure but different composition: 100% HA (algae derived) and HA/ß-tricalcium phosphate (ß-TCP) 20/80 (algae derived), and 2 with different structure but similar composition: HA/ß-TCP 20/80 (algae derived) and HA/ß-TCP 15/85 (synthetic). Calcium phosphate ceramics can be difficult to handle and contour during the surgeries. To improve handling, Poloxamer 407 (P407) was added to the 3 ceramics, and its effect on bone healing was also assessed. Bilateral calvarial defects created in the parietal bones of New Zealand white rabbits were left unfilled or were filled with autograft or one of the ceramics, with and without P407. Six weeks after operation, healing was evaluated qualitatively by histology and quantitatively by micro-computed tomography analysis and histomorphometry. All 3 calcium phosphate ceramics demonstrated osteoconductivity and performed similarly in supporting new bone formation, suggesting that the differences in their composition, structure, or degradation did not significantly affect their ability to promote bone healing in this application. Incorporating P407 did not impede osteoconductivity as HA and biphasic calcium phosphate combined with P407 performed similarly as when used alone for craniofacial defect repair.

Lemierre syndrome from an odontogenic source: a review for dentists.

Lemierre syndrome, which can result from a recent oropharyngeal or odontogenic infection, is characterized by clinical or radiographic signs of thrombosis of the internal jugular vein, distant infected emboli and the presence of anaerobic pathogens, usually Fusobacterium necrophorum. The septic emboli resulting from the infected thrombophlebitis of the internal jugular vein give the syndrome its constellation of central nervous system, pulmonary and many other manifestations including septic shock. This condition was so rare that, historically, it became known as the "forgotten disease," but an increasing frequency of reports indicates that Lemierre syndrome may not be so uncommon.

Augmentation of the maxillary sinus: comparison of bioimplants containing bone morphogenetic protein and autogenous bone in a rabbit model.

OBJECTIVE: To evaluate the effectiveness of various bioimplants used for augmentation of the maxillary sinus floor by means of a rabbit model. MATERIALS AND METHODS: Bone was harvested from the posterior iliac crest of 40 adult New Zealand white rabbits to allow bilateral augmentation of the floor of the maxillary sinus with autogenous bone or other materials. One of the following was grafted to the maxillary sinus of each rabbit: particulated autogenous bone, demineralized bone matrix (DBM), DBM combined with purified bone morphogenetic protein (BMP-DBM bioimplants) and bioimplants consisting of a poloxamer gel with BMP in 1 of 2 different doses. Animals were sacrificed at 2 or 8 weeks. Histologic examination was used to assess biologic healing in the various samples. Histomorphometry was used to demonstrate and quantify bone formation. RESULTS: After 2 weeks, the BMP-containing bioimplants had produced more new bone than any of the other materials. Particulated autogenous bone grafts produced less new bone initially (after 2 weeks), but the amount of bone produced by these grafts gradually increased, to levels comparable to the BMP-containing bioimplants by 8 weeks. For groups in which the poloxamer gel was used as a carrier for BMP or where BMP was used in combination with DBM, the amount of bone generated by 8 weeks was similar to that produced by autogenous bone. CONCLUSION: The rabbit maxillary sinus model allowed evaluation of multiple types of bioimplants that could be suitable for peri-implant maxillary reconstruction. BMP-containing bioimplants demonstrated promise as alternatives to autogenous bone grafts for sinus-augmentation procedures. These bioimplants had more rapid initial bone production than all other materials, including autogenous bone. In the future, such biomaterials may enable earlier placement of dental implants into augmented maxillary sinuses.

Reconstruction of 10 major mandibular defects using bioimplants containing BMP-7.

PURPOSE: The limitations and morbidity associated with autogenous bone grafting have driven the search for predictable bone substitutes and bioimplants. A novel method of reconstruction was tested in this case series. MATERIALS AND METHODS: Ten patients with major mandibular defects following resection of biopsy-proven ameloblastoma lesions or osteomyelitis of the mandibular body or ramus were included in this study. The resection defects were spanned with rigid reconstruction plates to hold the remaining mandibular segments in the correct position. The defects were filled with a bioimplant containing bone morphogenetic protein-7 (BMP-7) in a demineralized bone matrix (DBM) suspended in a reverse-phase medium to effect sustained BMP delivery. RESULTS: The postoperative course for all 10 patients was uneventful. Radiographic evidence of mandibular bone formation was found in all cases. At the end of 1 year, functional and esthetic reconstruction of the mandible was complete. CONCLUSION: Bioimplants containing BMP-7 in DBM suspended in a reverse phase medium were successful in restoring major mandibular defects in nonirradiated beds in this series of 10 patients.

Prevention of infective endocarditis: revised guidelines from the American Heart Association and the implications for dentists.

Infective endocarditis is a rare but life-threatening microbial infection of the heart valves or endocardium, most often related to congenital or acquired cardiac defects. The American Heart Association (AHA) recently updated its recommendations on prophylaxis during dental procedures. The revisions will have a profound impact on both the patient and the dental practitioner. The purpose of this paper is to review the pathogenesis and clinical presentation of infective endocarditis and discuss the 2007 AHA guidelines and their implications for dentists.

Fat embolism following posterior iliac graft harvest for jaw reconstruction: managing the complications of major surgery.

Oral and maxillofacial surgeons offer their patients a wide variety of surgical options that may be classified as major or minor surgery. Complications are part of surgery, but major surgery may lead to life-threatening complications that must be managed by the surgical team. Obtaining iliac graft tissue during oral and maxillofacial reconstruction carries the risk of rare but serious complications, such as deep vein thrombosis and fat embolism syndrome. In this paper we describe the latter postoperative complication experienced by a patient undergoing an otherwise routine major oral and maxillofacial reconstructive procedure. A discussion of the factors that stimulate fat embolism during or following surgical procedures is intended to help surgeons prevent this complication.

Small mouths ... Big problems? A review of scleroderma and its oral health implications.

Scleroderma, or progressive systemic sclerosis (PSS), an autoimmune rheumatic condition affecting the connective tissues, has a profound impact on oral health. Common orofacial findings include xerostomia, gastroesophageal reflux disease and limited mouth opening. This review article describes scleroderma, or PSS, and its various manifestations. The features of CREST syndrome and morphea are reviewed. Concerns relevant to the prevention of dental disease and the safe delivery of dental care in this group of challenging patients are emphasized.

Systemic lupus erythematosus: a review for dentists.

Systemic lupus erythematosus (SLE) is a chronic disease with far-reaching systemic implications. The hallmark feature in SLE is chronic inflammation. It can affect the skin, joints, kidneys, lungs, nervous system, serous membranes such as the pleura and pericardium, mucous membranes and other organs of the body. It is imperative that the dental practitioner be familiar with the broad range of systemic and oral implications, including the clinical and biochemical features of SLE. This review article offers an overview of the multiple organ systems affected by this complex heterogeneous disease process that are most relevant to both the general practitioner and the dental specialist. In particular, ways to recognize and manage the oral and dental manifestations of this systemic illness are presented.

Marble bone disease: a review of osteopetrosis and its oral health implications for dentists.

Osteopetrosis is one cause of osteosclerosis and may result in such serious oral complications as osteomyelitis and exposed necrotic bone. Dentists should be aware of patients with the disease because of its effect on osteoclast function, which results in impaired wound healing. The purpose of this paper is to review the causes, pathogenesis and differential diagnosis of osteopetrosis and to provide guidance to dentists on the management of patients with osteopetrosis.

A review of bisphosphonate-associated osteonecrosis of the jaws and its management.

Bisphosphonate-associated osteonecrosis (BON) may result in serious oral complications, such as osteomyelitis and chronic exposure of necrotic bone. Dentists must be familiar with this disorder and pay special attention to all patients on bisphosphonate therapy due to their defective osteoclast function and reduced osseous tissue vascularity, leading to impaired wound healing. The purpose of this paper is to review the history and pathogenesis of BON, discuss its differential diagnosis, provide guidance to dentists on possible measures to prevent BON and review the management of patients with BON.

Fractures of the supraorbital rim: principles and management.

Dentists may be asked to provide consultations for patients who have sustained trauma to their facial structures. Supraorbital rim fractures, although uncommon, must be recognized and promptly referred to an oral and maxillofacial surgeon or other specialist skilled in the management of facial bone fractures. Supraorbital rim fractures commonly coexist with other craniomaxillofacial injuries, especially with fractures of the anterior table of the frontal sinus. In this article, we review the frequency, management and complications associated with the treatment of supraorbital rim fractures in adults. A series of 5 cases was reviewed; 4 of the 5 patients were male, with a mean age of 21.6 years (range 17-28 years). All injuries involved the supraorbital rim and the anterior table of the frontal sinus and occurred concurrently with other facial injuries. Treatment ranged from conservative observation to open reduction and internal fixation of the fractures. No associated perioperative or postoperative complications occurred. The follow-up ranged from 6 months to 26 years, with satisfactory subjective esthetic outcomes in all cases.

Unilateral facial swelling caused by Ramsay Hunt syndrome resembles odontogenic infection.

Facial cellulitis and swellings of the head and neck are worrisome signs of odontogenic infection, which can be life threatening. Most head and neck infections are caused by bacterial pathogens. When treating such infections, dentists must also be aware of possible viral or fungal causes and their associated presentations. This report documents a case of viral infection that initially resembled a bacterial odontogenic infection. It is intended to familiarize dentists with the Ramsay Hunt syndrome and the need for prompt recognition and early definitive treatment.

Controlled bone formation using ultrasound-triggered release of BMP-2 from liposomes.

Recombinant human bone morphogenetic protein 2 (rhBMP-2) is used clinically to enhance implant-mediated bone regeneration. However, there are risks associated with the high rhBMP-2 dose that is required in the implant to mitigate diffusional loss over the therapeutic timespan. On-demand, localized control over delivery of rhBMP-2, days after implantation, would therefore be an attractive solution in the area of bone repair and reconstruction, yet this has posed a significant challenge, with little data to support in vivo efficacy to date. To address this, we have developed novel liposome-rhBMP-2 nanocomplexes that release rhBMP-2 in response to non-thermogenic, clinical diagnostic ultrasound exposure. In vitro validation shows that rhBMP-2 release is in proportion to applied ultrasound pressure and duration of exposure. Moreover, here we show in vivo validation of this ultrasound-triggered rhBMP-2 delivery system in a standard mouse bone regeneration model. Implanted into hindleg muscles, the liposome-rhBMP-2 nanocomplexes induced local bone formation only after ultrasound exposure. Such post-implantation control of delivery has potential to improve the safety, efficacy and cost of rhBMP-2 use in bone reconstruction. Furthermore, this first proof-of-concept demonstration of in vivo efficacy for ultrasound-triggered liposomal delivery of rhBMP-2 has broader implications for tunable delivery of a variety of drugs and biologics in medicine and tissue engineering.

Zygomatic bone: an additional donor site for alveolar bone reconstruction. Technical note.

This article describes a procedure to harvest bone from the zygoma for alveolar bone reconstruction. A detailed description of the bone harvesting procedure and a preliminary report of 3 patients undergoing alveolar bone reconstruction and simultaneous dental implant placement in the maxillary anterior area is presented. The technique is indicated when a modest amount of bone is needed, for example, to cover exposed implant threads and expand a narrow alveolar ridge. It also could be used as an additional source of bone with other intraoral donor sites. Surgical access to the zygoma is simple and can be performed using local anesthesia. Postoperative complications after zygomatic bone harvest are minimal.

Ameloblastic carcinoma: case report and literature review.

Ameloblastic carcinoma is a rare malignant lesion with characteristic histologic features and behaviour that dictates a more aggressive surgical approach than that of a simple ameloblastoma. However, reliable evidence of its biologic activity is currently unavailable due to the scarcity of well-documented cases. It occurs primarily in the mandible in a wide range of age groups; no sex or race predilection has been noted. It may present as a cystic lesion with benign clinical features or as a large tissue mass with ulceration, significant bone resorption and tooth mobility. Because the lesion is usually found unexpectedly after an incisional biopsy or the removal of a cyst, a guide to differential diagnosis is not usually useful. The identifying features of ameloblastic carcinoma must be known and recognized by dental practitioners. Our understanding of the histologic features of ameloblastic carcinoma is somewhat vague. The tumour cells resemble the cells seen in ameloblastoma, but they show cytologic atypia. Moreover, they lack the characteristic arrangement seen in ameloblastoma. The clinical course of ameloblastic carcinoma is typically aggressive, with extensive local destruction. Direct extension of the tumour, lymph node involvement and metastasis to various sites (frequently the lung) have been reported. Wide local excision is the treatment of choice. Regional lymph node dissection should be considered and performed selectively. Radiotherapy and chemotherapy seem to be of limited value for the treatment of ameloblastic carcinomas. At the moment, there are too few reported cases to make a definite recommendation regarding treatment. Close periodic reassessment of the patient is mandatory.

Bisphosphonate-associated osteonecrosis of the jaw in Ontario: a survey of oral and maxillofacial surgeons.

OBJECTIVE: Osteonecrosis of the jaw (ONJ) in association with use of bisphosphonate (BP) has been described primarily in cancer patients receiving high-dose intravenous BP. The frequency of the condition in patients with osteoporosis appears to be low. We evaluated the frequency of BP-associated ONJ in Ontario in the cancer population and in those receiving BP for osteoporosis and metabolic bone disease. METHODS: A survey developed by representatives of the Ontario Society of Oral and Maxillofacial Surgeons was mailed to Ontario oral and maxillofacial surgeons (OMFS) in December 2006, asking oral surgeons to provide information on cases of ONJ seen in the previous 3 calendar years (2004 to 2006). OMFS were subsequently contacted by telephone if they had not responded or if they had reported cases of ONJ. The frequency of ONJ in association with BP use was estimated from the number of patients with filled prescriptions for BP in Ontario between 2004 and 2006. The cumulative incidence of ONJ was calculated separately for patients using intravenous (IV) BP for cancer treatment and for patients using oral or IV BP for osteoporosis or other metabolic bone disease. RESULTS: Between 2004 and 2006, 32 ONJ cases were identified. Nineteen patients received IV BP for cancer treatment and 13 patients received oral or IV BP for osteoporosis or metabolic bone disease. Over a 3-year period the cumulative incidence of BP-associated ONJ was 0.442% of cancer patient observations (442 per 100,000) and 0.001% of osteoporosis or other metabolic bone disease observations (1.04 per 100,000). The relative risk of low dose IV/oral BP-associated ONJ was 0.002 (95% CI 0.001, 0.005) compared to high-dose IV BP. Other risk factors for ONJ were present in all cases in whom detailed assessment was available. The median duration of exposure to BP was 42 months (range 36 to 120 mo) and 42 months (range 11 to 79 mo) in osteoporosis patients and cancer patients, respectively. CONCLUSION: Over a 3-year period, the cumulative incidence for BP-associated ONJ was 0.442% of cancer patient observations (442 per 100,000) and 0.001% of osteoporosis or metabolic bone disease observations (1.04 per 100,000). This study provides an approximate frequency of BP-associated ONJ in Canada. These data need to be quantified prospectively with accurate assessment of coexisting risk factors.

The expression of bone matrix proteins induced by different bioimplants in a rabbit sinus lift model.

This study aimed to analyze the expression of bone matrix proteins and CD31 by immunohistochemistry after maxillary sinus grafting with different bioimplants in a rabbit model. Rabbit demineralized bone matrix (DBM), partially purified bovine bone morphogenetic proteins (BMP), a mixture of BMP with DBM (BMP/DBM), or particulated autogenous bone was grafted into the maxillary sinuses of 42 rabbits. Animals were sacrificed at 2 and 8 weeks. Immunohistochemistry was used to investigate the expression of type 1 collagen (COL1), osteonectin (ON), osteocalcin (OC), bone sialoprotein (BSP), osteopontin (OPN), and CD31. Sinuses grafted with BMP were filled with trabeculae of woven bone that was strongly immunoreactive for COL1, OC, ON, and BSP. BMP/DBM showed strongly positive immunoreactivity for these proteins within the newly formed bone, but weak immunoreactivity in the DBM particles. Immunoreactivity for COL1, OC, ON, and BSP in DBM sinuses was only seen in the osteoblasts rimming the grafted bone particles. The staining of autogenous bone graft sinuses was similar to those grafted with DBM. OPN staining was detected in autogenous bone graft, BMP/DBM, and BMP bioimplants. CD31 staining was strongest in BMP and BMP/noncollagenous matrix proteins sinuses. These results suggest that exogenous BMP enhances not only osteogenesis but also angiogenesis, an important part of bone repair.

Comparison of the osteoinductivity of bioimplants containing recombinant human bone morphogenetic proteins 2 (Infuse) and 7 (OP-1).

OBJECTIVES: Recent research has focused on application of growth factors such as bone morphogenetic proteins (BMPs) as alternatives to autogenous bone grafting. Two bone graft substitute bioimplants containing recombinant human BMPs (rhBMPs), Infuse (rhBMP-2) and OP-1 (rhBMP-7), are approved for human application but have never been compared side by side. The aim of this study was to provide a direct comparison of the osteoinductive activity of the 2 commercially available and approved rhBMP-containing bioimplants in their clinically available forms. STUDY DESIGN: The activity of rhBMP-2 and -7 in solution were compared in vitro using the C2C12 cell-based assay. The activity of Infuse and OP-1 bioimplants containing 52.5 microg of rhBMP-2 or rhBMP-7, respectively, were compared in vivo using a mouse muscle pouch assay and analyzed by microscopic CT (microCT) and histology. RESULTS: The in vitro results showed that rhBMP-2 stimulated greater alkaline phosphatase production than rhBMP-7 over various time points and concentrations. The in vivo results showed that OP-1 induced greater bone volume than Infuse. Both implants induced bone of equivalent quality based on microCT and histologic evaluation. CONCLUSION: In their clinically available forms, the rhBMP-7-containing OP-1 induced greater bone volume than the rhBMP-2-containing Infuse in the mouse muscle pouch model.

Effect of hyperbaric oxygen on demineralized bone matrix and biphasic calcium phosphate bone substitutes.

OBJECTIVES: The aim of this study was to assess the possible effect of hyperbaric oxygen (HBO) on the healing of critical-sized defects that were grafted with demineralized bone matrix (DBM) combined with Pluronic F127 (F127) to form a gel or putty, or a commercially available biphasic calcium phosphate (BCP), mixed either with blood or F127 to form a putty. STUDY DESIGN: Twenty New Zealand White rabbits were randomly divided into 2 groups of 10 animals each. Bilateral 15-mm calvarial defects were created in the parietal bones of each animal, resulting in 40 critical-sized defects. Group I defects were grafted with either DBM putty or DBM gel. Group II defects were grafted with either BCP or BCP putty. Five animals from each group received HBO treatment (100% oxygen, at 2.4 ATA) for 90 minutes per day 5 days a week for 4 weeks. The other 5 animals in each group served as a normobaric (NBO) controls, breathing only room air. All animals were humanely killed at 6 weeks. The calvariae were removed and analyzed by micro computed tomography (mCT) and histomorphometry. RESULTS: mCT analysis indicated a higher bone mineral content (BMC, P < .05), bone volume fraction (BVF; P < .001), and bone mineral density (BMD; P < .001) of the defects grafted with BCP rather than DBM. Furthermore, the voxels that were counted as bone had a higher tissue mineral density (TMD) in the BCP- than in the DBM-filled defects (P < .001). Histologically complete bony union over the defects was observed in all specimens. Histomorphometric analysis showed that DBM-filled defects had more new bone (P < .007) and marrow (P < .001), and reduced fibrous tissue compared with the BCP defects (P < .001) under NBO conditions. HBO treatment reduced the amount of fibrous tissue in BCP filled defects (P < .05), approaching levels similar to that in matching DBM-filled defects. HBO also resulted in a small but significant increase in new bone in DBM-grafted defects (P < .05). CONCLUSION: Use of DBM or BCP promoted healing in these critical-sized defects. Hyperbaric oxygen therapy resulted in a slight increase in new bone in DBM-grafted defects and much larger reduction in fibrous tissue and matching increases in marrow in BCP-grafted defects, possibly through increased promotion of angiogenesis.