Oral and Maxillofacial Surgery

Bisphosphonates inhibit bone resorption and thus bone renewal by suppressing the recruitment and activity of osteoclasts thus shortening their life span. Recently three bisphosphonates, Pamidronate (Aredia; Novartis Pharmaceuticals, East Haven, NJ), Zoledronate (Zometa; Novartis Pharmaceuticals), and Alendronate (Fosamax; Merck Co, West Point, VA) have been linked to painful refractory bone exposures in the jaws.One hundred-nineteen total cases of bisphosphonate-related bone exposure were reviewed.Thirty-two of 119 patients (26%) received Aredia, 48 (40.3%) received Zometa, 36 (30.2%) received Aredia later changed to Zometa, and 3 (2.5%) received Fosamax. The mean induction time for clinical bone exposure and symptoms was 14.3 months for those who received Aredia, 12.1 months for those who received both, 9.4 months for those who received Zometa, and 3 years for those who received Fosamax. Sixty-two (52.1%) were treated for multiple myeloma, 50 (42%) for metastatic breast cancer, 4 (3.4%) for metastatic prostate cancer and 3 (2.5%) for osteoporosis. Presenting findings in addition to exposed bone were 37 (31.1%) asymptomatic, 82 (68.9%) with pain, 28 (23.5%) mobile teeth, and 21 (17.6%) with nonhealing fistulas. Eighty-one (68.1%) bone exposures occurred in the mandible alone, 33 (27.7%) in the maxilla, and 5 (4.2%) occurred in both jaws. Medical comorbidities included the malignancy itself 97.5%, previous and/or maintenance chemotherapy 97.5%, Dexamethasone 59.7%. Dental comorbidities included the presence of periodontitis 84%, dental caries 28.6%, abscessed teeth 13.4% root canal treatments 10.9%, and the presence of mandibular tori 9.2%. The precipitating event that produced the bone exposures were spontaneous 25.2%, tooth removals 37.8%, advanced periodontitis 28.6%, periodontal surgery 11.2%, dental implants 3.4% and root canal surgery 0.8%.Complete prevention of this complication in not currently possible. However, pre-therapy dental care reduces this incidence, and non-surgical dental procedures can prevent new cases. For those who present with painful exposed bone, effective control to a pain free state without resolution of the exposed bone is 90.1% effective using a regimen of antibiotics along with 0.12% chlorohexidine antiseptic mouth.

Background The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection.

This study reviewed the literature on cone-beam computerized tomography (CBCT) imaging of the oral and maxillofacial (OMF) region. A PUBMED search (National Library of Medicine, NCBI; revised 1 December 2007) from 1998 to December 2007 was conducted. This search revealed 375 papers, which were screened in detail. 176 papers were clinically relevant and were analyzed in detail. CBCT is used in OMF surgery and orthodontics for numerous clinical applications, particularly for its low cost, easy accessibility and low radiation compared with multi-slice computerized tomography. The results of this systematic review show that there is a lack of evidence-based data on the radiation dose for CBCT imaging. Terminology and technical device properties and settings were not consistent in the literature. An attempt was made to provide a minimal set of CBCT device-related parameters for dedicated OMF scanners as a guideline for future studies.

, FICD § Purpose: The purpose of this study is to estimate the frequency and describe the clinical characteristics of patients diagnosed with bisphosphonate-associated osteonecrosis of the jaws (ONJ) in Australia. Materials and Methods: Cases of ONJ were identified in 2004 and 2005 primarily by a postal survey of Australian Oral and Maxillofacial Surgeons (OMS) with additional cases from other dental specialists and the Commonwealth of Australia Adverse Drug Reaction Committee (ADRAC). The clinical characteristics were recorded. The frequency of ONJ cases was estimated from prescription and dental extraction data. Univariate and bivariate statistics were calculated. Results: One hundred fifty-eight cases of ONJ were identified. These were primarily in patients with bone malignancy (72%) and the main trigger was dental extraction (73%). The reported number of cases varied between different Australian States with the highest frequency being reported in the States with the best integrated health systems. The frequency of ONJ in osteoporotic patients, mainly on weekly oral alendronate was 1 in 2,260 to 8,470 (0.01% to 0.04%) patients. If extractions were carried out, the calculated frequency was 1 in 296 to 1,130 cases (0.09% to 0.34%). The total dose of oral alendronate at the onset of ONJ was 9,060 (Ϯ7,269) mg. The frequency of ONJ for Paget's disease cases was 1 in 56 to 380 (0.26% to 1.8%). If extractions were carried out, the calculated frequency of ONJ was 1 in 7.4 to 48 (2.1% to 13.5%). The frequency of ONJ in bone malignancy cases, treated with mainly intravenous zoledronate or pamidronate was 1 in 87 to 114 (0.88% to 1.15%). If extractions were carried out, the calculated frequency of ONJ was 1 in 11 to 15 (6.67% to 9.1%) The total dose of pamidronate was 3,285 (Ϯ2,530) mg and zoledronate 62 (Ϯ54.28) mg at the onset of ONJ. The median time to onset of ONJ was 12 months for zoledronate, 24 months for pamidronate, and 24 months alendronate. Conclusions: Before the prescription of bisphosphonates for bone disease the patient should be made dentally fit so that the need for subsequent dental extractions is minimized. Appropriate informed consent for the risk of ONJ for different bisphosphonates, for osteoporosis, and malignancy both in general and in particular for dental extractions can be provided using this data.

Background: Several prognostic models have been developed to stage hepatocellular carcinoma (HCC) but there is no general consensus on which is the most reliable. We compared three prognostic indices (Okuda, CLIP, and BCLC scoring systems) in a large series of cirrhotic patients with HCC undergoing nonsurgical treatment in terms of their ability to classify patients into different risk groups Methods: We retrospectively studied 268 Italian patients with HCC. A total of 146 patients were treated with ablation, 132 with percutaneous ethanol injection, and 14 with radiofrequency ablation; 103 underwent transcatheter arterial chemoembolisation and 19 had supportive care alone. Factors determining survival were analysed by univariate and multivariate analysis using the Kaplan-Meier method and Cox proportional hazard regression models. Okuda, CLIP, and BCLC scores evaluated before treatment were applied. Results: Median survival was 25.7 months. In a multivariate analysis, portal vein thrombosis, a fetoprotein, total bilirubin, and tumour size were significant predictors of survival. Okuda, CLIP, and BCLC scores were all able to predict survival (p,0.001). They identified two, four, and six risk groups, respectively, with a median survival ranging from 27 to 19 months for Okuda, 30 to 5 months for CLIP, and 43 to 7 months for BCLC. Conclusions: Both CLIP and BCLC scores were more effective than the Okuda score in stratifying patients into different risk groups with early-intermediate HCC. However, the BCLC scoring system gave a better prediction of prognosis in patients with disease diagnosis at a very early stage.

Background: The COVID-19 pandemic has disrupted routine hospital services globally. This study estimated the total number of adult elective operations that would be cancelled worldwide during the 12 weeks of peak disruption due to COVID-19. Methods: A global expert response study was conducted to elicit projections for the proportion of elective surgery that would be cancelled or postponed during the 12 weeks of peak disruption. A Bayesian-regression model was used to estimate 12-week cancellation rates for 190 countries. Elective surgical case-mix data, stratified by specialty and indication (surgery for cancer versus benign disease), were determined. This case mix was applied to country-level surgical volumes. The 12-week cancellation rates were then applied to these figures to calculate the total number of cancelled operations. Results: The best estimate was that 28 404 603 operations would be cancelled or postponed during the peak 12 weeks of disruption due to COVID-19 (2 367 050 operations per week). Most would be operations for benign disease (90⋅2 per cent, 25 638 922 of 28 404 603). The overall 12-week cancellation rate would be 72⋅3 per cent. Globally, 81⋅7 per cent of operations for benign conditions (25 638 922 of 31 378 062), 37⋅7 per cent of cancer operations (2 324 070 of 6 162 311) and 25⋅4 per cent of elective caesarean sections (441 611 of 1 735 483) would be cancelled or postponed. If countries increased their normal surgical volume by 20 per cent after the pandemic, it would take a median of 45 weeks to clear the backlog of operations resulting from COVID-19 disruption. Conclusion: A very large number of operations will be cancelled or postponed owing to disruption caused by COVID-19. Governments should mitigate against this major burden on patients by developing recovery plans and implementing strategies to restore surgical activity safely. * Members of the COVIDSurg Collaborative are co-authors of this study and are listed in Appendix S1 (supporting information)

The purpose of this report is to show the feasibility and potential advantages of using internal devices for distraction osteogenesis in the management of maxillofacial skeletal deficiencies. Distraction osteogenesis was used to correct a variety of maxillofacial skeletal deformities in five patients. One patient underwent bilateral Le Fort III advancement aided by distraction, three patients underwent mandibular ramus lengthening, and one patient underwent segmental alveolar reconstruction by distraction. The devices were activated by either a transcutaneous or transmucosal pin. After achievement of the desired skeletal transport, the activating pins were disengaged and removed from the distraction device. This allowed the distraction device to remain submerged and to stabilize the site of the consolidating bone. All patients achieved lengthening of their jaws. However, premature consolidation was noted in two patients, and one patient had significant relapse. Development of internal distraction devices is important to address the limitations of currently available biphasic systems. Potential benefits of internal devices include 1) elimination of skin scarring caused by translation of transcutaneous fixation pins, 2) improved patient compliance during the fixation or consolidation phase because there is no external component, and 3) improved stability of the attachment of the device to the bone.

This paper discusses the topic of evaluating systems for health and entertainment when specifically targeting the older adult population. Building upon and extending on two previous studies that used a well-known discount usability evaluation method, heuristic evaluation, as well as a list of heuristics specifically created to evaluate smartphone apps that keep older adults' needs and characteristics in mind, this paper presents the assessment of the previous aggregated list of heuristics by ten experts after using it. Results show that the list of heuristics used in our previous studies does receive a positive assessment by the ten evaluators in terms of their appropriateness, completeness, usefulness, and clarity. Moreover, this paper reinforces that despite being a conventional and mature method, heuristic evaluation does offers valuable feedback regarding user interface flaws.

A 30-year-old Southeast Asian man with facial swelling, fever, and unintentional weight loss was found to have leukopenia and thrombocytopenia. He underwent endoscopic sinus surgery, which confirmed extranodal NK/T-cell lymphoma, nasal type, and a blood and bone marrow examination, which was negative for involvement but yielded the diagnosis of alpha-E thalassemia. The patient received chemotherapy, radiotherapy, and a stem cell transplant with 100% engraftment.

The present study assessed whether peritoneal macrophages isolated from cirrhotic patients produce nitric oxide (NO) and express NO synthase type II (NOS II) mRNA and protein. Patients with cirrhosis and ascites without peritonitis or with unresolved or resolved spontaneous bacterial peritonitis (SBP) were studied. Following paracentesis, ascites NO + NO content (NOx) was measured. Peritoneal macrophages from ascites were seeded on well plates, and NO in the medium was determined. NOx was higher in patients with unresolved or resolved SBP than in cirrhotic patients without peritonitis. Macrophages of patients with SBP or resolved SBP produced NO after 30 hours in culture, but those obtained from patients without peritonitis did not. Reverse-transcription polymerase chain reaction (RT-PCR) and immunocytochemical analysis revealed the presence of a clear signal for NOS II mRNA and protein in macrophages of SBP patients, regardless of whether or not the infection subsided. Therefore, peritoneal macrophages isolated from cirrhotic patients with unresolved or resolved SBP produce NO and express the NOS II mRNA and protein, suggesting that NOS II may contribute to the control of SBP, or to its associated pathology, in human cirrhosis.

Temporomandibular joint (TMJ) ankylosis in children is a challenging problem. Surgical correction is technically difficult and the incidence of recurrence after treatment is high. The purpose of the present report is to describe the protocol currently used at the Massachusetts General Hospital for the management of TMJ ankylosis in children. It has been our observation that the most common cause of treatment failure is inadequate resection of the ankylotic mass and failure to achieve adequate passive maximal opening in the operating room. The 7-step protocol consists of 1) aggressive excision of the fibrous and/or bony ankylotic mass, 2) coronoidectomy on the affected side, 3) coronoidectomy on the contralateral side, if steps 1 and 2 do not result in a maximal incisal opening greater than 35 mm or to the point of dislocation of the unaffected TMJ, 4) lining of the TMJ with a temporalis myofascial flap or the native disc, if it can be salvaged, 5) reconstruction of the ramus condyle...

Ischemia predisposes orthopaedic trauma patients to delayed fracture healing or non-union. The goal of this study was to test the ability of bone morphogenetic protein 7 (BMP7) to stimulate fracture repair in an ischemic environment. Ischemic fractures were generated in male adult mice by resecting the femoral artery prior to the creation of a non-stabilized tibia fracture. Recombinant human BMP7 (rhBMP7, 50µg) was injected into the fracture site immediately after surgery. Histomorphometric analyses revealed that rhBMP7 induced more cartilage at day 7, more callus and bone at days 14 and 28, and more adipose tissue and fibrous tissue at days 7, 14 and 28 compared to controls (n=5/group/time). At day 28, all fractures treated with rhBMP7 (50µg, n=5) healed, whereas only 3 of 5 control fractures exhibited slight bony bridging. In addition, we found that rhBMP7 (both 10 and 50µg) significantly increased the amount of cartilage compared to controls in stabilized fractures, confirming its chondrogenic effect. No significant effects of rhBMP7 on tissue vascularization were observed at 3 days after fracture. Lastly, using bone marrow transplantation we determined that no donor-derived osteocytes or chondrocytes were present in rhBMP7 treated fractures, suggesting rhBMP7 did not recruit mesenchymal stem cells from the bone marrow to the fracture site. In conclusion, our results indicate that rhBMP7 is a promising treatment for fractures with severely disrupted blood supply.

Purpose: Osteonecrosis of the jaw (ONJ) is a serious complication associated with bisphosphonate therapy, but its epidemiology in the setting of oral bisphosphonate therapy is poorly understood. The present study examined the prevalence of ONJ in patients receiving chronic oral bisphosphonate therapy. Materials and Methods: We mailed a survey to 13,946 members who had received chronic oral bisphosphonate therapy as of 2006 within a large integrated health care delivery system in Northern California. Respondents who reported ONJ, exposed bone or gingival sores, moderate periodontal disease, persistent symptoms, or complications after dental procedures were invited for examination or to have their dental records reviewed. ONJ was defined as exposed bone (of Ͼ8 weeks' duration) in the maxillofacial region in the absence of previous radiotherapy. Results: Of the 8,572 survey respondents (71 Ϯ 9 years, 93% women), 2,159 (25%) reported pertinent dental symptoms. Of these 2,159 patients, 1,005 were examined and an additional 536 provided dental records. Nine ONJ cases were identified, representing a prevalence of 0.10% (95% confidence interval 0.05% to 0.20%) among the survey respondents. Of the 9 cases, 5 had occurred spontaneously (3 in palatal tori) and 4 occurred in previous extraction sites. An additional 3 patients had mandibular osteomyelitis (2 after extraction and 1 with implant failure) but without exposed bone. Finally, 7 other patients had bone exposure that did not fulfill the criteria for ONJ. Conclusions: ONJ occurred in 1 of 952 survey respondents with oral bisphosphonate exposure (minimum prevalence of 1 in 1,537 of the entire mailed cohort). A similar number had select features concerning for ONJ that did not meet the criteria. The results of the present study provide important data on the spectrum of jaw complications among patients with oral bisphosphonate exposure.

Lipomas represent about 1 to 5% of all neoplasms of the oral cavity. Although relatively common, few large series of intraoral lipomas and its variants are seen in the literature. Therefore, the authors present the clinical, histological and immunohistochemical features of 46 cases of intraoral lipomas reviewed from the files of the University of Campinas Dental School from 1970 to 2001. Most of the cases affected adults, without gender predilection, and the main involved sites were the buccal mucosa (21 cases), tongue (six cases), lips (six cases) and floor of mouth (five cases). The histological analysis revealed 21 cases of lipoma, 18 fibrolipomas, four intramuscular lipomas, two minor salivary gland lipomas and one spindle cell lipoma. PCNA and ki-67 expression indexes were higher in spindle cell lipoma, intramuscular lipomas and fibrolipomas compared to common lipomas, but the differences were not statistically significant. All lesions were removed surgically and none showed recurrence, regardless of the various proliferative activities.

Recurrent aphthous ulcers represent a very common but poorly understood mucosal disorder. They occur in men and women of all ages, races and geographic regions. It is estimated that at least 1 in 5 individuals has at least once been afflicted with aphthous ulcers. The condition is classified as minor, major, and herpetiform on the basis of ulcer size and number. Attacks may be precipitated by local trauma, stress, food intake, drugs, hormonal changes and vitamin and trace element deficiencies. Local and systemic conditions, and genetic, immunological and microbial factors all may play a role in the pathogenesis of recurrent aphthous ulceration (RAU). However, to date, no principal cause has been discovered. Since the aetiology is unknown, diagnosis is entirely based on history and clinical criteria and no laboratory procedures exist to confirm the diagnosis. Although RAU may be a marker of an underlying systemic illness such as coeliac disease, or may present as one of the features ...

Purpose: Demineralization of a thin layer of bone over a root prominence after corticotomy surgery can optimize the response to applied orthodontic forces. This physiologic response is consistent with the regional acceleratory phenomenon process. When combined with alveolar augmentation, one is no longer strictly at the mercy of the original alveolar volume and osseous dehiscences, and fenestrations can be corrected over vital root surfaces. This is substantiated with computerized tomographic and histologic evaluations. Two case reports are presented that demonstrate the usefulness of the accelerated osteogenic orthodontics technique in de-crowding and space closing for the correction of dental malocclusions. Materials and Methods: Orthodontics is combined with full-thickness flap reflection, selective alveolar decortication, ostectomy, and bone grafting to accomplish complete orthodontic treatment. Results: Rapid tooth movement was demonstrated in both cases and stability up to 8 years of retention.

Objective: Fine needle aspiration (FNA) cytology aims to assist the clinician in the management of patients with salivary gland (SG) masses. We aimed to present our twelve -year experience concerning FNA in SG lesions to address the importance of this procedure. Study Design: Aspirates of 221 cases from SG lesions were reviewed retrospectively. In 151 cases, the FNA diagnosis was consistent with histologic findings. Results: FNA diagnoses were benign in 72.8 %, and malignant in 19.2% of the cases. Eleven cases were reported as suspicious for malignancy. The diagnostic sensitivity was 94% and specificity was 100%. Eight of 43 malignant cases were clinically referred with no evidence for a malignant tumor initially, but FNA was reported as malignant or suspicious for malignancy. Conclusions: Our study documents that FNA is a highly sensitive and specific procedure. It provides preoperative recognition of benign and malignant tumors. Besides that, it helps to prevent unnecessary surgery in SG swellings. To our knowledge, this article is the largest series in Turkish literature concerning FNA of SG. We think that our results are suggestive for FNA to be a primary diagnostic tool in SG lesions.

Purpose: The aim of this report was to present an integrated 3-dimensional (3D) virtual approach toward cone-beam computed tomography-based treatment planning of orthognathic surgery in the clinical routine. Materials and Methods: We have described the different stages of the workflow process for routine 3D virtual treatment planning of orthognathic surgery: 1) image acquisition for 3D virtual orthognathic surgery; 2) processing of acquired image data toward a 3D virtual augmented model of the patient's head; 3) 3D virtual diagnosis of the patient; 4) 3D virtual treatment planning of orthognathic surgery; 5) 3D virtual treatment planning communication; 6) 3D splint manufacturing; 7) 3D virtual treatment planning transfer to the operating room; and 8) 3D virtual treatment outcome evaluation. Conclusions: The potential benefits and actual limits of an integrated 3D virtual approach for the treatment of the patient with a maxillofacial deformity are discussed comprehensively from our experience using 3D virtual treatment planning clinically.

Purpose: Trauma is the leading cause of diseases and death in children. The goal of this study was to assess the impact of the main causes of accidents among children resulting in pediatric craniomaxillofacial trauma. Patients and Methods: Between 1991 and 2000, data for 3,385 patients younger than 15 years of age who sustained a total of 6,060 craniomaxillofacial injuries were recorded for cause of injury, age and gender distribution, frequency and type of injury, injury mechanisms, localization and frequency of soft tissue injuries, dentoalveolar trauma, facial bone fractures, and concomitant injuries. Univariate statistical analyses were followed by logistic regression analyses for the 3 injury types to determine the impact of the main injury causes on the type of injury at different ages in pediatric facial trauma patients. Results: Play (58.2%), sport (31.8%), and traffic accidents (5%), acts of violence (3.9%), and other causes (1.1%) were noted. A total of 389 patients (11.5%) had 615 fractures, 2,582 patients (76.3%) had 3,384 dentoalveolar injuries, and 1,697 patients (50.1%) had 2,061 soft tissue injuries. The girl-to-boy ratio was 3:5, and the mean age was 7 Ϯ 4.4 years. For children sustaining facial trauma, logistic regression analyses revealed increased risks for fractures (ϩ238%) and soft tissue lesions (ϩ89%) in children involved in traffic accidents. Dental trauma was more frequent (Ͼϩ38%) in both sport and play accidents (all P Ͻ .001). Conclusions: This study dissected the distinct impact of injury mechanisms in pediatric craniomaxillofacial trauma. Logistic regression analyses revealed statistically highly significant outcome differences in pediatric facial trauma depending on the injury mechanism.

Background: Sinus augmentation with simultaneous implant placement without bone graft material is a hotly debated technique. This technique could be improved and secured by the use of an autologous leukocyte-and platelet-rich fibrin (PRF) (Choukroun's technique) concentrate. The objectives of this study were to assess the relevance of PRF clots and membranes as the sole filling material during a lateral sinus lift with immediate implantation using radiologic and histologic analyses in a case series.

This study determined the prevalence and specific anatomic types of disc displacement in asymptomatic versus symptomatic subjects using magnetic resonance imaging (MRI). A detailed MRI assessment was performed on both temporomandibular joints (TMJ) in 76 volunteers and 102 successive patients. Attention was placed on the functional aspects of disc displacement with and without reduction and on the anatomic aspects of disc displacement in the anterior, lateral, medial, anterolateral, and anteromedial directions. These assessments were made by radiologists blinded to the clinical information. Disc displacement was found in at least one joint in 25 of 76 (33%) of asymptomatic subjects and 79 of 102 (77%) of symptomatic subjects. The anatomic types of disc displacement between groups was not statistically significant (P = .55). However, there was a significant difference between asymptomatic and symptomatic subjects, with an odds ratio of 3.91 for disc displacement with reduction and 42.71 for disc displacement without reduction (P < .001). Although there was a 33% prevalence of disc displacement in asymptomatic volunteers, there was a highly significant difference in the prevalence of internal derangement in symptomatic subjects. Bruxing was statistically linked to TMJ disc displacement and could explain the anatomic variation in abnormal disc position.

Using a one-stage surgical protocol, 75 implants ad modum Brånemark of three different designs were inserted in 15 edentulous mandibles of high bone density. All implants were followed with repeated stability measurements by means of resonance frequency analysis (RFA) from implant placement to connection of the fixed prostheses (3-4 months), in order to evaluate possible stability changes during healing. It was shown that the resonance frequency (RF) values slightly decreased for the majority of the implants during the study period independent of design. Consequently, the results of the present study indicated that the implants were as stable at time of placement as when measured at 3-4 months post-surgery, i.e. when the prostheses were attached. The available data support the concept of direct loading of implants when inserted between the mental interforaminal regions. One implant failed during healing and the corresponding RF measurement disclosed, at six weeks post-surgery, a val...

Bisphosphonates are a widely used class of drugs that have been proven to be extremely useful in the prevention and treatment of osteoporosis, hypercalcemia of malignancy, and bone metastases associated with multiple myeloma, breast cancer, and other solid tumors. In the past several years there have been numerous reports describing the occurrence of Osteonecrosis of the Jaws (ONJ) associated with these drugs. In the great majority of cases this condition develops after surgical manipulation of the oral tissues. The natural history and pathophysiology of ONJ however, remains unknown at the present time. Furthermore, whether the ONJ lesion initiates in the oral mucosa or derives from the underlying bone has not been determined. In this report we describe the effect of pamidronate, a second generation bisphosphonate, on oral mucosal cells. Our results show that bisphosphonate pre-treatment of oral mucosal cells inhibits proliferation and wound healing at clinically relevant doses and that this inhibition is not due to cellular apoptosis.

Sykaras N, Triplett RG, Nunn ME, Iacopino AM, Opperman LA. Effect of recombinant human bone morphogenetic protein-2 on bone regeneration and osseointegration of dental implants Abstract: Recombinant human bone morphogenetic protein-2 (rhBMP-2) induced bone regeneration and osseointegration was evaluated in bony defects created within the hollow chamber of endosseous dental implants in 14 foxhound dogs. Bilateral extractions of mandibular premolars were performed and surgical implantation of 104 hollow cylinder implants followed after 8 weeks of healing. Experimental implants had their hollow chamber filled with 20 mg of rhBMP-2 delivered with a bovine collagen carrier, whereas the control implants had their apical chamber left empty. Dogs were followed for 2, 4, 8 and 12 weeks. Histomorphometric evaluation and immunohistochemical analysis were performed. Minimal bone was regenerated at 2 weeks for both groups. At 4 weeks, bone fill averaged 23.48% for the rhBMP-2 and 5.98% for the control group (PϽ0.05). At 8 weeks, mean bone fill was 20.94% and 7.75% for the rhBMP-2 and the controls, respectively (PϽ0.05). At 12 weeks, mean bone fill was 31.39% and 24.31% for the rhBMP-2 and control implants, respectively (PϾ0.05). Bone-implant contact (BIC) increased for both groups over time and at 8 weeks the rhBMP-2 BIC value was 18.65% and for the control 7.22% (PϽ0.05). At 12 weeks, the BIC was 43.78% and 21.05% for the rhBMP-2 and the control group, respectively (PϽ0.05). Immunohistochemical staining for type II collagen was positive only for parts of the collagen carrier and formation of cartilaginous intermediate was not observed in any of the specimens. The results suggest that, in confined defects adjacent to dental implants, rhBMP-2 can induce bone regeneration in close apposition to the implant surface.

Twenty-three patients with obstructive sleep apnea syndrome (OSAS) documented by polysomnography underwent maxillomandibular advancement via Le Fort I, and sagittal ramus split osteotomies followed by rigid fixation with miniplates and bicortical screws. Partial turbinectomies and septal reconstruction were simultaneously performed. Pre-and postoperative cephalometric radiographs were analyzed by computer. Hyoid position and posterior airway space changes did not correlate with clinical success. The surgical success (respiratory disturbance index less than 10) with maxillomandibular advancement was 65%. The total desaturations below 90% greatly decreased. Ninety-six percent of patients were subjectively and objectively improved. Obstructive sleep apnea syndrome (OSAS) is characterized by repeated collapse of the upper airway producing hypopnea, apnea, and ultimately, oxygen desaturation of hemoglobin. The effects of repeated desaturation significantly alter normal cardiovascular and pulmonary function, resulting in pulmonary and systemic hypertension, and arrhythmias, which, if untreated, can lead to an early death. IT2 The hypopneic and apneic episodes, with frequent arousal from sleep, disrupt normal sleep patterns. Ineffective sleep results in sleep fragmentation and excessive daytime sleepiness (EDS), which can have a profound effect on social interactions and ability to work or perform normal activities, such as driving an automobile.3

This article addresses the incidence of specific complications and, where possible, offers a preventive or management strategy. Injuries of the inferior alveolar and lingual nerves are significant issues that are discussed separately in this text. Surgical removal of third molars is often associated with postoperative pain, swelling, and trismus. Factors thought to influence the incidence of complications after third molar removal include age, gender, medical history, oral contraceptives, presence of pericoronitis, poor oral hygiene, smoking, type of impaction, relationship of third molar to the inferior alveolar nerve, surgical time, surgical technique, surgeon experience, use of perioperative antibiotics, use of topical antiseptics, use of intra-socket medications, and anesthetic technique. Complications that are discussed further include alveolar osteitis, postoperative infection, hemorrhage, oro-antral communication, damage to adjacent teeth, displaced teeth, and fractures.

Nineteenth-century surgery is primarily based on the knowledge of the anatomy of the region of interest. The discovery and application of X-rays marks the beginning of medical imaging, a revolutionary development still continuing. The use of imaging techniques allows preoperative evaluation of pathology and anatomy, but it is required that the surgeon transfers this visual information to the actual operation site just in imagination. Consequently the wish to have a ''glasslike patient'' arises, where relevant information from preoperative imaging is directly available to the surgeon's perception.

Composite resection of the mandible or maxilla will often leave the affected patient with an orthognathically unsatisfactory outcome. With full-thickness resection of either jaw, but most commonly the mandible, the realignment of the free-floating mandibular segments can be malpositioned with an inappropriate condylar arrangement leading to malocclusion. Traditional techniques of reconstruction are often inexact, and poor planning or communication between the resecting and reconstructive teams can lead to suboptimal orthognathic reconstruction regardless of how well each individual operation was performed. In this article we present our experience with an evolving technique of orthognathically precise jaw reconstruction. The foundation of our work is built on communication between the reconstructive and resecting teams. The hallmark of these techniques has been meticulous preoperative planning of all procedures by use of 3-dimensional (3D) stereolithographic models. This evolution has led to our current practice of virtual surgical simulation using reconstructed 3D im-ages and creation of staged models to provide precise osteotomies and plating yielding an ideal functional outcome.

Although overexpression of the epidermal growth factor receptor (EGFR; ErbB1) has been correlated with poor prognosis in breast and other cancers, clinical trials of ErbB1 inhibitors have shown limited efficacy in inhibiting tumor proliferation. To evaluate other possible roles of ErbB1 in tumor malignancy besides proliferation, we have developed a series of tools for analysis of intravasation. Overexpression of ErbB1 in MTLn3 mammary adenocarcinoma cells results in increased intravasation and lung metastasis from tumors formed by injection of cells in the mammary fat pad. However, increased ErbB1 expression has no effect on primary tumor growth and lung seeding efficiency of cells injected i.v. Chemotactic responses to low concentrations of EGF in vitro and cell motility in vivo in the primary tumor measured using intravital imaging are significantly increased by ErbB1 overexpression. The increased cell motility is restricted to ErbB1overexpressing cells in tumors containing mixtures of cells expressing different ErbB1 levels, arguing for a cell-autonomous effect of increased ErbB1 expression rather than alteration of the tumor microenvironment. In summary, we propose that ErbB1 overexpression makes more significant contributions to intravasation than growth in some tumors and present a novel model for studying ErbB1 contributions to tumor metastasis via chemotaxis and intravasation. (Cancer Res 2006; 66(1): 192-7) Note: E. Sahai is currently at the Tumour Cell

Purpose: The purpose of this prospective multicenter study was to assess the accuracy of a computeraided surgical simulation (CASS) protocol for orthognathic surgery. Materials and Methods: The accuracy of the CASS protocol was assessed by comparing planned outcomes with postoperative outcomes of 65 consecutive patients enrolled from 3 centers. Computergenerated surgical splints were used for all patients. For the genioplasty, 1 center used computergenerated chin templates to reposition the chin segment only for patients with asymmetry. Standard intraoperative measurements were used without the chin templates for the remaining patients. The primary outcome measurements were the linear and angular differences for the maxilla, mandible, and chin when the planned and postoperative models were registered at the cranium. The secondary outcome measurements were the maxillary dental midline difference between the planned and postoperative positions and the linear and angular differences of the chin segment between the groups with and without the use of the template. The latter were measured when the planned and postoperative models Received from the Methodist

The topic of condylar injury in adults has generated more discussion and controversy than any other in the field of maxillofacial trauma. It is an important subject because such injuries are common and complications of trauma to the temporomandibular joint (TMJ) are far-reaching in their effects. Why are there so many different methods to treat this injury? How can seemingly disparate treatment options all produce satisfactory outcomes in the majority of patients? The reason lies with the biological adaptations that occur within the masticatory system that are poorly understood, not readily quantifiable, and variable from one person to the next. This discussion presents our current understanding of the adaptations that must occur to provide the patient with a satisfactory outcome. The adaptations for patients treated open are different than for those treated closed. However, it is when these adaptations fail to occur that unsatisfactory outcomes occur, regardless of how they were treated.

h      h  the use of transpalatal distractors have deserved emphasis, particularly in patients with consolidated growth. This provides increased structure, through graded tensile forces between surgically separated bone segments. However, there are controversies about the advantages and limitations of this technique. This report describes the case of 26-year-old a male patient treated by surgically assisted rapid maxillary expansion with transpalatal distractor associated with the removal of the third molars.

This study presents a computer-assisted planning system for dysgnathia treatment. It describes the process of information gathering using a virtual articulator and how the splints are constructed for orthognathic surgery. The deviation of the virtually planned splints is shown in six cases on the basis of conventionally planned cases. In all cases the plaster models were prepared and scanned using a 3D laser scanner. Successive lateral and posterior-anterior cephalometric images were used for reconstruction before surgery. By identifying specific points on the X-rays and marking them on the virtual models, it was possible to enhance the 2D images to create a realistic 3D environment and to perform virtual repositioning of the jaw. A hexapod was used to transfer the virtual planning to the real splints. Preliminary results showed that conventional repositioning could be replicated using the virtual articulator.

Purpose: We sought to show that marsupialization can be a definitive treatment for the odontogenic keratocyst (OKC). Materials and Methods: Ten patients (10 males and 4 females) between the ages of 11 and 64 with biopsy-proven OKC (8 mandibular and 2 maxillary) measuring between 2 and 8 cm were treated by marsupialization consisting of excision of the overlying mucosa and the opening of a 1-cm window into the cystic cavity and, where possible, suturing of the cyst lining to the oral mucosa. Immunohistologic determination of bcl-2 was done for all samples of cyst lining. The cavities were kept open either by vigorous use of a home syringe by the patient or by suturing into place the flange and short length of a nasopharyngeal airway. Once the cyst had largely filled in, histologic material was taken from the base of the residual depression and studied by light microscopy and bcl-2 expression. Results: In the 10 patients, the OKCs completely resolved both clinically and radiographically. The time taken for resolution varied from 7 to 19 months. In all cases, the histologic material obtained after marsupialization showed normal epithelium only, with no signs of cystic remnants, daughter cysts, or budding of the basal layer of the epithelium. At initial biopsy, bcl-2 was expressed in the keratocyst lining, but not in the histologic material obtained after marsupialization. Follow-up time ranged from a minimum of 1.8 years to a maximum of 4.8 years. Teeth at the periphery of the cysts were observed to upright and erupt. Conclusions: All 10 OKCs resolved completely after marsupialization. Teeth within the cyst were found to be upright and erupt. Marsupialization requires a cooperative patient who will irrigate the cavity and keep it open. It appears that the cyst lining is replaced by normal epithelium during this treatment.

Purpose: The purpose of this study was to establish clinical feasibility of our 3-dimensional computeraided surgical simulation (CASS) for complex craniomaxillofacial surgery. Materials and Methods: Five consecutive patients with complex craniomaxillofacial deformities, including hemifacial microsomia, defects after tumor ablation, and deformity after TMJ reconstruction, were used. The patients' surgical interventions were planned by using the authors' CASS planning method. Computed tomography (CT) was initially obtained. The first step of the planning process was to create a composite skull model, which reproduces both the bony structures and the dentition with a high degree of accuracy. The second step was to quantify the deformity. The third step was to simulate the entire surgery in the computer. The maxillary osteotomy was usually completed first, followed by mandibular and chin surgeries. The shape and size of the bone graft, if needed, was also simulated. If the simulated outcomes were not satisfactory, the surgical plan could be modified and simulation could be started over. The final step was to create surgical splints. Using the authors' computer-aided designing/ manufacturing techniques, the surgical splints and templates were designed in the computer and fabricated by a stereolithographic apparatus. To minimize the potential risks to the patients, the surgeries were also planned following the current planning methods, and acrylic surgical splints were created as a backup plan.

The introduction of bisphosphonates has increased in the last decade following their indication for metastatic bone diseases, osteoporosis, hypercalcaemia of malignancy and Paget’s disease. Although bisphosphonates have been used clinically for more than three decades there have been no documented long-term complications of their effects on the jaws until recently, where there is now growing evidence of the influence of bisphosphonates on osteonecrosis of the jaws. The aim of this paper is to report a case of this newly described complication, to review this phenomenon, including the clinical implications and to reiterate current clinical guidelines for management of patients in which bisphosphonate therapy is indicated. To the best of our knowledge this is the first reported case of bisphosphonate-induced necrosis of the jaw in South Africa.