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Biomedical subjects

A N Goss

Publications and source records attributed to A N Goss.

At least 19 recordsLinked to original sources

The role of muscle grafts in temporomandibular joint ankylosis: short-term experimental study in sheep.

The temporalis muscle flap can be used as an inter-positional graft placed into a gap arthroplasty site in temporomandibular joint (TMJ) ankylosis. The purpose of this study was to investigate the role of the muscle graft in sheep. Five pure-bred adult Merino sheep were used and ankylosis was induced in all right TMJs. At 3 months, the ankylosis was released by gap arthroplasty and reconstructed with a masseter muscle graft, because the temporalis muscle is short and poorly vasculized in sheep. The sheep were killed at 3 months after muscle grafting. The maximal mouth opening was recorded before and after operation and at death. The joints were examined radiologically and histologically. In 4 sheep mouth opening remained at the pre-operative level. A clear radiolucent space remained between the smooth temporal and ramus stumps. Histologically, the muscle graft remained vital but with some fibrous tissue formation between the bone ends. One sheep developed an infection at the operative site following the muscle graft; this partly resolved with antibiotics, but the TMJ developed a fibrous reankylosis that was demonstrated clinically, radiologically and histologically. These results indicate that an uncomplicated temporalis muscle graft reconstruction with gap arthroplasty is a successful and stable procedure in human TMJ ankylosis.

Animals↗

The dental implications of bisphosphonates and bone disease.

In 2002/2003 a number of patients presented to the South Australian Oral and Maxillofacial Surgery Unit with unusual non-healing extraction wounds of the jaws. All were middle-aged to elderly, medically compromised and on bisphosphonates for bone pathology. Review of the literature showed similar cases being reported in the North American oral and maxillofacial surgery literature. This paper reviews the role of bisphosphonates in the management of bone disease. There were 2.3 million prescriptions for bisphosphonates in Australia in 2003. This group of drugs is very useful in controlling bone pain and preventing pathologic fractures. However, in a small number of patients on bisphosphonates, intractable, painful, non-healing exposed bone occurs following dental extractions or denture irritation. Affected patients are usually, but not always, over 55 years, medically compromised and on the potent nitrogen containing bisphosphonates pamidronate (Aredia/Pamisol), alendronate (Fosamax) and zolendronate (Zometa) for non-osteoporotic bone disease. Currently, there is no simple, effective treatment and the painful exposed bone may persist for years. The main complications are marked weight loss from difficulty in eating and severe jaw and neck infections. Possible preventive and therapeutic strategies are presented although at this time there is no evidence of their effectiveness. Dentists must ask about bisphosphonate usage for bone disease when recording medical histories and take appropriate actions to avoid the development of this debilitating condition in their patients.

Adult↗

Patients with artificial joints: do they need antibiotic cover for dental treatment?

This study reviews whether patients with artificial joints need antibiotic cover for dental treatment. Generally in Australia the practice has developed of giving most patients with artificial joints antibiotic prophylaxis for a wide range of dental procedures. This is partly on anecdotal grounds, partly historical and partly for legal concerns. It has been encouraged by some guidelines. Scientifically, the risk and the benefit of each step in the process needs to be analysed. This review shows that the risk of an artificial joint becoming infected from a bacteraemia of oral origin is exceedingly low whereas the risk of an adverse reaction to the antibiotic prophylaxis is higher than the risk of infection. If all patients with artificial joints receive antibiotic prophylaxis then more will die from anaphylaxis than develop infections. Factors which balance the risk benefit are if the patient is seriously immunocompromised, if the joint prosthesis is failing or chronically inflamed and if the dental procedures, such as from extractions and deep periodontal scaling, produce high level bacteraemias. Recommendations to rationalize antibiotic prophylaxis for patients with artificial joints are presented.

Antibiotic Prophylaxis↗

Antibiotic prophylaxis for dentoalveolar surgery: is it indicated?

Usually dentists in Australia give patients oral antibiotics after dentoalveolar surgery as a prophylaxis against wound infection. When this practice is compared to the principle of antibiotic prophylaxis in major surgery it is found to be at variance in a number of ways. In major surgery, the risk of infection should be high, and the consequences of infection severe or catastrophic, before antibiotic prophylaxis is ordered. If it is provided then a high dose of an appropriate spectrum antibiotic must be present in the blood prior to the first incision. Other factors which need to be considered are the degree of tissue trauma, the extent of host compromise, other medical comorbidities and length of hospitalization. Standardized protocols of administration have been determined and evaluated for most major surgical procedures. Dentoalveolar surgery is undoubtedly a skilled and technically challenging procedure. However, in contrast to major surgical procedures, it has a less than five per cent infection rate and rarely has severe adverse consequences. Dentoalveolar surgery should be of short duration with minimal tissue damage and performed in the dental chair under local anaesthesia. Controlled studies for both mandibular third molar surgery and placement of dental implants show little or no evidence of benefit from antibiotic prophylaxis and there is an adverse risk from the antibiotic. This review concludes that there is no case for antibiotic prophylaxis for most dentoalveolar surgery in fit patients. In the few cases where it can be considered, a single high preoperative dose should be given.

Antibiotic Prophylaxis↗

Antibiotic prophylaxis for endocarditis: time to reconsider.

Some cardiac conditions require antibiotic prophylaxis for some types of dental treatment to reduce the risk of infective endocarditis (IE). All medical and dental practitioners are familiar with this practice but tend to use different regimens in apparently similar circumstances. Generally, the trend has been to prescribe antibiotics if in doubt. This review explores the evidence for antibiotic prophylaxis to prevent IE: does it work and is it safe? The changing nature of IE, the role of bacteraemia of oral origin and the safety of antibiotics are also reviewed. Most developed countries have national guidelines and their points of similarity and difference are discussed. One can only agree with the authority who describes antibiotic guidelines for endocarditis as being 'like the Dead Sea Scrolls, they are fragmentary, imperfect, capable of various interpretations and (mainly) missing!' Clinical case-controlled studies show that the more widely antibiotics are used, the greater the risk of adverse reactions exceeding the risk of IE. However, the consensus is that antibiotic prophylaxis is mandatory for a small number of high-risk cardiac and high-risk dental procedures. There are a large number of low-risk cardiac and dental procedures in which the risk of adverse reactions to the antibiotics exceeds the risk of IE, where prophylaxis should not be provided. There is an intermediate group of cardiac and dental procedures for which careful individual evaluation should be made to determine whether IE or antibiotics pose the greater risk. These categories are presented. All medical and dental practitioners need to reconsider their approach in light of these current findings.

Antibiotic Prophylaxis↗

Cardiac murmurs: echocardiography in the assessment of patients requiring antibiotic prophylaxis for dental treatment.

BACKGROUND: Traditionally patients who indicate that they have a heart murmur or who indicate that they have had rheumatic fever are given antibiotic prophylaxis for dental treatment. This is commonly done without further assessment of the patient's actual endocarditis risk. Echocardiography is a non-invasive method of assessing cardiac valve function and haemodynamics. METHODS: Consecutive patients who were referred to a private practice oral and maxillofacial surgeon for dentoalveolar surgery and indicated that they had a cardiac problem and usually had antibiotic prophylaxis, were evaluated. Those with a clear indication for prophylaxis, for example had prosthetic heart valves or previous infective endocarditis, received antibiotic prophylaxis. Where there was uncertainty, they were referred for an echocardiogram, and if abnormal, a formal cardiology review. RESULTS: Three hundred and seventy patients out of approximately 20 000 (1.85 per cent) indicated that they had a cardiac murmur and usually received antibiotic prophylaxis for dental treatment between 1 February 1997 and 1 February 2005. Two hundred and sixty-two (71 per cent) were female and 108 (29 per cent) were male; age range 0.7 to 98 years, average 37.6 years. Two hundred and seventy (72 per cent) had normal hearts with no indication for antibiotic prophylaxis. Of the 100 (28 per cent) patients with abnormal findings, they were on average older; 49.5 years, range 0.7 to 87 years. Of these, 50 (14 per cent) met current indications for antibiotic prophylaxis. CONCLUSION: Patients who present for dental treatment indicating that they require antibiotic prophylaxis for cardiac condition need to be fully evaluated. In this study only 50 of 370 patients (14 per cent) required antibiotic prophylaxis. The remaining 320 (86 per cent) would have no benefit but a risk of adverse reaction to the antibiotic.

Adolescent↗

Severe odontogenic infections.

BACKGROUND: Severe odontogenic infections are serious potentially lethal conditions. Following the death of a patient in the authors' institution this study was initiated to determine the risk factors, management and outcome of a consecutive series of patients. METHODS: All patients admitted to the Royal Adelaide Hospital under the care of the Oral and Maxillofacial Surgery Unit with odontogenic infections in calendar year 2003 were investigated. Detailed information relative to their pre-presentation history, surgical and anaesthetic management and outcome was obtained and analysed. RESULTS: Forty-eight patients, 32M, 16F, average age 34.5, range 19 to 88 years were treated. All presented with pain and swelling, with 21 (44 per cent) having trismus. Forty-four (92 per cent) were as a result of dental neglect and four (8 per cent) were regular dental patients having endodontic treatment which failed. Of those known to have been treated prior to presentation, most had been on antibiotics. Most patients had aggressive surgical treatment with extraction, surgical drainage, high dose intravenous antibiotics and rehydration. The hospital stay was 3.3 (range 1-16) days. Patients requiring prolonged intubation and high dependency or intensive care (40 per cent) had longer hospitalization. No patient died and all fully recovered. CONCLUSION: Severe odontogenic infections are a serious risk to the patient's health and life. Management is primarily surgical with skilled anaesthetic airway management. Antibiotics are required in high intravenous doses as an adjunct and not as a primary treatment.

Adult↗

Practice patterns of oral and maxillofacial surgeons in Australia: 1990 and 2000.

This study was undertaken to describe practice patterns of oral and maxillofacial surgeons in Australia and compare trends over time. All registered oral and maxillofacial surgeons in Australia were surveyed in 1990 and 2000 using mailed self-complete questionnaires. Data were available from 79 surgeons from 1990 (response rate = 73.8%) and 116 surgeons from 2000 (response rate = 65.1%). In both 1990 and 2000 the majority of surgeons worked 80+% of the time in the private sector (64.1 and 71.4%), had 80+% referrals from dental versus medical sources (74.0 and 74.7%), and had 80+% of patients from dentoalveolar rather than major maxillofacial surgery (70.7 and 69.7%). The percentage of dual qualified (dental plus medical degree) surgeons increased from 2.5% in 1990 to 17.1% in 2000 (P < 0.05; chi2). In 2000, surgeons who worked less than 80% in the private sector were more likely to report being overworked (57.9%) and that more surgeons were required in the public sector (65.0%) than those who worked 80% or more private (17.0 and 24.0%, respectively). Multivariate linear regressions of annual non-dentoalveolar surgical procedures per surgeon showed (P < 0.05) higher provision of implant (beta = 0.362), TMJ (beta = 0.267) and bone graft surgery (beta = 0.208) in 2000 compared to 1990, and higher provision of orthognathic (beta = 0.199), implant (beta = 0.194) and bone graft surgery (beta = 0.289) by dual qualified surgeons compared to those with only dental qualifications. Despite the mix of cases remaining predominantly dentoalveolar there was some change over time for selected non-dentoalveolar surgical procedures, with growth in the percentage of medically qualified surgeons and differences in surgery rates by qualification.

Adult↗

Service provision by patient and visit characteristics in Australian oral and maxillofacial surgery: 1990 to 2000.

This study was set-up to describe main areas of service by patient and visit characteristics and compare trends in services between 1990 and 2000. All registered oral and maxillofacial surgeons in Australia were surveyed in 1990 and 2000 using mailed self-complete questionnaires. Service provision data were collected from a one-week log. Data were available from 79 surgeons from 1990 (response = 73.8%) and 116 surgeons from 2000 (response = 65.1%). Service distributions were dominated by dentoalveolar surgery in 1990 (66.6%) and 2000 (63.5%). Multivariate analysis showed: patient age, location of visit (office/theatre/inpatient facility) and referral source (general/specialist and dental/medical) were associated with all five main areas of service; type of visit (consult/operation/review) was associated with four main areas; patient sex and place of visit (private/public) was associated with three main areas; the only significant change over time was an increased percentage of orthognathic surgery, odds ratio = 1.4 (95% CI: 1.1-1.7) times higher in 2000 compared to 1990. Main areas of service were associated with a range of explanatory variables such as age and sex of patients, and place, location and type of visit, and referral source. However, the distribution of services remained relatively stable over time.

Adolescent↗

The diagnosis and surgical management of major salivary gland pathology.

BACKGROUND: Major salivary gland pathology is an uncommon but important finding which may initially present to general dental and medical practitioners. The consequences of misdiagnosis are important, as acute obstruction and neoplasia are the main pathological lesions diagnosed. The purpose of this study was to analyze a consecutive series of major gland pathologies treated surgically to determine diagnostic and treatment problems. METHODS: A retrospective analysis of all cases of the major salivary glands treated on an inpatient surgical basis over a five-year period by the Oral and Maxillofacial Surgery Unit of the Royal Adelaide Hospital was performed. Particular emphasis was placed on the referring diagnosis as compared to the final diagnosis. RESULTS: Fifty-four patients had surgical management of 62 major salivary glands over the five-year period. By gland, 18 (33.3 per cent) were parotid, 35 (51.1 per cent) submandibular and nine (16.6 per cent) were sublingual. Fifty-one (82 per cent) of all lesions were inflammatory and 11 (18 per cent) neoplastic. The most common presentations were swelling (72 per cent) and pain (33 per cent). Most patients were referred by general dentists (37 per cent), followed by general medical practitioners (32 per cent) and specialists (28 per cent). The referring diagnosis was correct for only 45 per cent of the dentists but 76 per cent for the general medical practitioners and 87 per cent for the specialists. Only two of the 11 gland neoplasms were correctly identified as neoplasms, both by specialists. The morbidity of the surgical treatment was low. CONCLUSION: The general dental practitioner is often the first health professional with the opportunity to assess salivary gland pathology, and therefore needs to be aware of the presenting signs and symptoms of major salivary gland lesions.

Adolescent↗

Current concepts of the management of dental extractions for patients taking warfarin.

BACKGROUND: Controversy has surrounded the correct management of patients therapeutically anticoagulated with warfarin who require dental extractions. The risk of bleeding must be weighed up against the risk of thromboembolism when deciding whether to interfere with a patient's warfarin regimen. An improved understanding of the importance of fibrinolytic mechanisms in the oral cavity has resulted in the development of various local measures to enable these patients to be treated on an outpatient basis. METHODS: A review of the literature was undertaken. This was supplemented by the authors' clinical trials and extensive clinical experience with anticoagulated patients. RESULTS: Various protocols for treating patients taking warfarin have been reviewed and summarized and an overview of the haemostatic and fibrinolytic systems is presented. A protocol for management of warfarinized patients requiring dental extractions in the outpatient setting is proposed. CONCLUSIONS: Patients therapeutically anticoagulated with warfarin can be treated on an ambulatory basis, without interruption of their warfarin regimen provided appropriate local measures are used.

Anticoagulants↗

Regeneration of the mandibular condyle after unilateral condylectomy and myotomy of the masseter in lambs.

We investigated the degree of regeneration of the mandibular condyle after unilateral condylectomy and myotomy of the masseter in growing lambs. Four 10-week-old lambs had unilateral condylectomy and myotomy of the superficial layer of the masseter on the right side, and were killed 3 months later. The joints were examined radiologically and histologically. All joints showed poor regeneration of the condylar head. In the medial plane there was partial condylar and articular cartilage reformation, but in the lateral plane there was neither condylar nor cartilaginous reformation. The articular cartilage of the temporal bone was thicker in the medial plane and the disc was thicker in the central plane, than in unoperated joints. We conclude that unilateral condylectomy and myotomy of the masseter in the growing period results in poor regeneration of the condyle.

Animals↗

Quantitation of chondroitin-sulfates, disaccharides and hyaluronan in normal, early and advanced osteoarthritic sheep temporomandibular joints.

OBJECTIVE: To determine the relationship between synovial fluid, chondroitin sulfate disaccharide and hyaluronic acid to differing degrees of experimental temporomandibular joint (TMJ) osteoarthritis (OA). DESIGN: Twenty-four merino sheep were divided into three groups and had different TMJ surgical procedures to produce OA. Group I; control (six sheep), Group II; disc perforation (nine sheep) and Group III; disc perforation and articular damage (nine sheep). Synovial fluid was collected initially and at sacrifice at 3 months. Chondroitin 4-sulfate, chondroitin 6-sulfate and hyaluronic acid were measured and correlated to the OA histologic score. RESULTS: The chondroitin-sulfate levels were significantly increased (Group I to Group II P< 0.001; Group I to Group III P< 0.001), the hyaluronic acid levels decreased (Group I to Group II P< 0.01; Group I to Group III P< 0.01) with the increasing OA score. CONCLUSION: Chondroitin-sulfate and hyaluronic acid show a correlation with surgically created TMJ osteoarthritis in sheep model.

Animals↗

Unilateral mandibular condylectomy in lambs.

The purpose of this experimental study was to investigate the degree of regeneration of the mandibular condyle after unilateral condylectomy in 10-week-old lambs. The lambs were killed three months after the operation, and the joints examined radiologically and histologically. Scoring systems were used to assess the radiological changes and histological regeneration of the condyle. All joints showed regeneration of the condylar head postoperatively. The maximum degree of regeneration occurred on the medial side rather than the central or lateral areas. There was a significant correlation among the medial, central, and lateral planes (P<0.05). The reformed articular cartilage was irregular and thin (P<0.01), and the disc was thick in the central plane (P<0.01) compared with the control joints. The temporal bone was normal. This study shows that unilateral condylectomy in the growing period results in some condylar regeneration particularly on the medial side and reformation of some irregular and thin articular cartilage.

Animals↗

Costochondral grafts in reconstruction of the temporomandibular joint after condylectomy: an experimental study in sheep.

The purpose of this study was to investigate the effect of costochondral grafts in the temporomandibular joint (TMJ) in sheep. Five pure-bred adult Merino sheep were used. The condyle alone was resected and replaced with a costochondral graft from the 13th rib. The sheep were killed 3 months after operation. The range of jaw movements before and after operation and at death were recorded. The joints were examined radiologically, macroscopically, and histologically. A new condylar head with normal configuration and function developed. Histologically, the chondrocytes were arranged in a fashion similar to that of a normal joint. All inferior joint spaces showed fibrous adhesions between the condylar head and disc. This study showed that, when such grafts are used to replace the condyle in an otherwise normal sheep TMJ, they fused to the ramus and reconstituted a nearly normal, fully functional joint.

Analysis of Variance↗

Effect of partial immobilization on reconstruction of ankylosis of the temporomandibular joint with an autogenous costochondral graft:an experimental study in sheep.

The purpose of this study was to show the effect of partial immobilization of a costochondral graft reconstruction of an ankylosed temporomandibular joint (TMJ) in five adult sheep. Ankylosis was induced in all right TMJs. At three months, a graft was inserted and partially immobilized. Three months after the second operation, four sheep were killed by an overdose with pentothal. One sheep was killed at one month because of infection. Functionally, the body weight, which decreases with ankylosis, did not recover after insertion of the graft and the range of jaw movements got worse. Histologically, the grafts were well attached to the mandibular rami in three of four joints. In one joint, the graft showed signs of resorption and a foreign body reaction. We conclude that, if the reconstructed joint is partially immobilized, then there will be a degree of reankylosis. There was also a high failure rate.

Analysis of Variance↗