Comparative study of the osteoblastic activity of two implant systems (Endopore versus Entegra) utilizing single photon emission computed tomography (SPECT): experimental study in pigs model.

Implantology has been an important component of dental management for over forty years, and during that period, many configurations of implant materials and methods have been developed. As empirical and clinical research yield new implant materials, there has been need to test and compare these materials to provide the most cost-effective and efficient implants. Evaluation of efficiency of implants has relied heavily on histological and radiological methods, but these one-dimensional measurement methods fail to evaluate the osteoblastic activity and osseointegration properties of putative implants. In this report, we describe the use of a quantitative single photon emission computed tomography (SPECT) as a tool for comparing the osseointegrating capabilities of two types of implants.

Emerging applications of an experimental single photon emission computed tomography: an analysis of 16 areas of interest in the pig's model.

This paper aims to affirm various new applications of single photon emission computed tomography (SPECT) technique by utilizing the pig's models. Evaluation and subsequent analysis of SPECT results was conducted on the jaws of eight experimental pigs with a total of 16 areas of interest. The various reasons for which each experiment was conducted were evaluated and these reasons include: i) validation of a new bone grafting technique for closure of oro-antral communications, ii) comparison of autogeneous bone graft with other bone grafts, iii) sequential confirmation of osteoblastic activity of the sandwich bone regeneration technique with another technique, iv) validation of the use of a new membrane for guided tissue regeneration (GTR), v) validation of the fact that osseointegration is better with beaded implants than with threaded implants, and vi) validation of the fact that GTR is essential for immediate implant practice. The outcome of this evaluation is critically analysed against the background of the substantial clinical evidence where applicable, so as to appreciate the position of SPECT Following the evaluation of 16 areas of interest in eight experimental pigs, it was shown that experimental SPECT was valuable in the validation of the above reasons. It appears to be a modality that can continuously be utilized to validate and compare situations which would display osteoblastic activities. It is concluded that the bone scintigraphy imaging technique accurately reflects osteoblastic activities and can now be used to validate osseointegration of any implant or bone-grafting system. This can be done in conjunction with histological and histomorphometic analysis and such results obtained from SPECT should be correlated with the histological and histomorphometric analysis if available.

Mathematical model for osteobstruction in bone regeneration mechanisms: a headway in skeletal tissue engineering.

In this paper, we formulate a mathematical model for the evaluation of parameters responsible for the retardation and eventual acceleration of bone regeneration on the contralateral side of the mandible of experimental animals, following the discovery of a new mechanism of bone regeneration called the osteobstruction mechanism (a negative mechanism of bone regeneration as opposed to the well established and extensively documented positive mechanisms such as osteogenesis, osteoinduction and osteoconduction). This osteobstructive mechanism was demonstrated by episodes of overtaking and reovertaking on single photon emission computed tomography (SPECT) following evaluation of osteoblastic activities in a sequential animal experiment to validate both the Ogunsalu sandwich technique (a double guided tissue technique; D-GTR) and the interceed membrane technique (a single guided tissue regeneration technique; S-GTR) utilizing SPECT, histological and histomorphometric evaluation. This work is now given special attention in terms of mathematical analysis because of limited experimental observations since experiments cannot be observed infinitely. Mathematical modelling is as such essential to generalize the results of this osteobstructive mechanism in bone regeneration. We utilize the Fisher's equation to describe bone cell mobilization during bone regeneration by two different techniques: the Ogunsalu sandwich bone regeneration technique (D-GTR) and the S-GTR.

Serum lipids, proteins and electrolyte profiles in rats following total body irradiation.

OBJECTIVE: Serum lipid and electrolyte imbalances are common in critically ill patients undergoing radiation therapy. Although multiple disease states and medication may be responsible for the development of these disorders, the aim of this research is to sequentially document the effect of total body radiation on body function utilizing the sequential changes in the serum lipids, electrolytes and protein in rats. METHODS: Serum protein and lipids contents were assessed using kits while electrolytes were assessed with flame photometry in rats exposed to total body irradiations of 1.27 Gy/min in cumulative doses to the fourth irradiation at five-day intervals. RESULTS: Total cholesterol and triacylglycerols serum levels were significantly reduced by irradiation (p < 0.05). No significant differences between experimental and control groups for HDL-C serum levels were detected. Serum electrolyte concentration remained within the normal range after each total body irradiation. Sodium, bicarbonate and chloride were significantly (p < 0.05) higher than control while potassium and creatinine were significantly reduced after the first irradiation only. Sodium/potassium ratio was significantly (p < 0.05) elevated. Serum protein was significantly (p < 0.05) elevated with increasing radiation. CONCLUSION: There are subtle but significant changes in serum lipids, electrolytes and protein after total body irradiation of normal rats. These variations could be due to non-specific stress reactions; as such, they are important markers in radiation induced injury diagnosis.

Prevalence and antimicrobial susceptibility pattern of pathogens isolated from patients with juvenile periodontitis in Jamaica: a prospective multi-centre study of 15 cases over a 15-year period.

Prevalence and antimicrobial susceptibility pattern of most frequent pathogens isolated from patients treated with juvenile periodontitis at three separate dental centres in Jamaica from 1989 to 2003 were studied. Swabs were taken from these patients periodontal pathologic pocket or root of most of their teeth with active disease processes. These swabs were processed at the microbiology department of the University Hospital of the West Indies Kingston, Jamaica and the Microbiology laboratory, School of Veterinary Medicine, Faculty of Medical Sciences, University of the West Indies, St. Augustine, Trinidad and Tobago. The identification of the micro-organisms from positive cultures and their antimicrobial susceptibility profile were performed using standard microbiological procedures and dick diffusion (Kirby-Bauer) methods. Over 80% of the patients were females. The most frequent micro-organisms isolated were Enterobacter (40.5%), followed by Klebsiella species (19%) and Acinetobacter species (10.8%). Actinobacillus actinomycetemcomitans, a widely known key pathogen in juvenile periodontal diseases was encountered only in 5.4% (2/37) of the cases in this study The most frequent organism isolated were still highly susceptibility to the commonly used and available antimicrobials such as amoxycillin/clavulanate, trimethoprim/sulphamethoxazole, chloramphenicol and aminoglycosides. The most frequent pathogens encountered in this study were totally different from what obtains in other places. There is the need to be aware of microbes in other countries during the microbiology investigations ofjuvenile periodontitis and that the antimicrobial chemotherapy should always be based on susceptibility test results. Surgical treatment for mechanical debridement of the site and bone grafting with guided tissue regeneration should be mandatory in conjunction with specific antimicrobial chemotherapy

Ameloblastoma in Jamaica--predominantly unicystic: analysis of 47 patients over a 16-year period and a case report on re-entry cryosurgery as a new modality of treatment for the prevention of recurrence.

OBJECTIVE: To analyse all the cases of ameloblastoma seen in the two major public Hospitals in Jamaica over a 16-year period, and to compare the results with what has been previously documented by other authors in the literature. A new treatment modality for prevention of recurrence of ameloblastoma is described. SUBJECTS AND METHODS: The case files of patients histologically diagnosed to have ameloblastoma at both the Kingston Public Hospital and Cornwall Regional Hospital in Jamaica from 1980 to 1995 were retrieved and information about this odontogenic tumour was documented. The analysis revealed that uncystic ameloblastoma was predominant (95%) and solid ameloblastoma was about 5%. It was not therefore surprising that the average age in the study was 29.1 years, with a peak in the 10-19-year age group. No peripheral ameloblastoma was diagnosed. RESULTS: A total of 47 new cases of ameloblastoma was recorded between 1980 and 1995. This number accounted for 16.03% of all jaw bone lesions in Jamaica and 38.2% of jaw bone lesions of odontogenic origin during this period. These cases of ameloblastoma accounted for 67% of odontogenic tumours with the exception of the odontomas. The mean age was 29.1 (range 13-67) years. The male:female ratio was 1:1.14). Only 3 cases involved the maxilla. Of significance, is the case of bilateral ameloblastoma with no continuity to the anterior region, and also the case of unilateral involvement of the mandible and the maxilla in the same patient. Re-entry cryosurgery (a procedure in which cryosurgery is done after a specified period from the primary surgical procedure) after excisional biopsy of a relatively small cystic ameloblastoma of the maxilla was negative for recurrence. CONCLUSION: The clinicopathological presentation of ameloblastoma in Jamaica is not different from what has been documented by other authors throughout the world; however; we report two unique cases --a case of bilateral ameloblastoma of the mandible and a case of unilateral involvement of the mandible and maxilla in the same patient. We suggest that re-entry cryosurgery before recurrence be considered in the management of ameloblastoma for the prevention of recurrence.

Comparative study of osteoblastic activity of same implants (Endopore) in the immediate extraction site utilizing single photon emission computerized tomography: peri-implant autogeneous bone grafting with GTR versus no peri-implant bone grafting--experimental study in pig model.

The study was designed to exploit the single photon emission computerized tomography (SPECT) to compare osteoblastic activity of two implant systems: an Endopore implant (Beaded implants) placed immediately into an extraction socket in conjunction with peri-implant autogenous grafting supplemented with a guided tissue regeneration (GTR) technique, and an Endopore implant placed immediately into the extraction socket without peri-implant grafting and GTR. Endopore implants of the same size (12 mm x 4.1 mm INT-Hex) were placed in fresh extraction sockets in the canine-tooth region of the pigs jaw. The implant on the right side had peri-implant bone grafting utilizing autogenous bone together with cytoplast resorbable GTR membrane, whilst the implant on the left side received no peri-implant bone grafting. Osteoblastic activity was evaluated 81 days (11 weeks and 4 days) post implantation using the SPECT imaging technique. The SPECT imaging revealed more osteoblastic activity on the side with peri-implant bone grafting as compared with the site without peri-implant bone grafting. The result suggests that peri-implant bone grafting with GTR around the immediate implant showed more osteoblastic activity and thus enhanced osseointegration when compared with the implant without bone grafting and GTR. Bone grafting and GTR should be encouraged as a standard procedure with dental implants.

Review of six cases of maxillary ameloblastoma from the West Indies: re-entry cryosurgery as prophylactic surgical intervention.

Maxillary ameloblastoma is a rare histopathological entity. A total of six cases of histologically confirmed maxillary ameloblastoma from the West Indies is reviewed. Three of the cases were taken from a total of 47 histologically confirmed ameloblastoma over a 15-year period (1980-1995) from two major maxillofacial units in Jamaica. Two other cases were from documentation in Jamaica between 2000 and 2002, one of which occurred in a 13-year-old girl (these two patients have been followed-up periodically to 2006). The sixth case was from the records of the maxillofacial department of the University of the West Indies in Trinidad and Tobago. This last patient, at a recent review, has inoperable recurrence. These cases were reviewed with respect to demographics (patient's age and gender), location and extent of tumour, radiological features, concurrent involvement of the mandible, treatment with special emphasis on current treatment modality and follow-up. The findings do not differ from what has been documented by other authors from other parts of the world. Because of the radiographic anatomy of the maxilla, recurrence may be detected late despite such occurring earlier following initial surgical management. It is for this reason that we suggest re-entry cryosurgery for prevention of recurrence for maxillary ameloblastoma. The only case of maxillary ameloblastoma that had re-entry cryosurgery continues to benefit from absence of recurrence at periodic follow-ups at four years post-primary surgical management (which was enucleation).

Single photon emission computerized tomography in the evaluation of the osteoblastic activities of a new bone regeneration technique: analysis of 12 mandibular sites in six experimental pigs.

OBJECTIVES: To utilize single photon emission computerized tomography performed in sequence to determine the osseo-integrating capabilities and osteoblastic activities of a new bone regeneration technique called the membrane--sandwich technique (Ogunsalu sandwich bone regenerating technique) and to compare the quality and quantity of bone formed by this bone regeneration unit to bone regeneration obtained by using the same particulate bone grafting material covered with interceed (another type of bio-resorbable membrane). DESIGN AND METHOD: Single photon emission computerized tomography bone imaging was performed in sequence on the mandible of a total of 6 pigs on both the right and left side (total of 12 sites) at two and a half hours following the injection of technetium 99m methylene diphosphate. Imaging was performed using a Siemen Orbitar II gamma camera. The projection data was acquired in a 128 x 128 matrix over 180 arc and SPECT reconstruction was performed using a filtered back projector method with a Shepp-Logan Hanning filter and a cut-off frequency of 0.4. The surgical defect on one side of the jaw was treated with the sandwich unit with Bio-oss particulate bone within it, while the other side contained the same quantity of Bio-oss as in the left side but just covered with interceed membrane. The osteoblastic uptake on the side with the classical sandwich was compared to the side with the particulate bone covered with interceed membrane for dynamic physiological activities. The average activity for both sides was calculated and compared. RESULT: For all the 12 sites, osteoblastic activities were recorded and indicated that vascularized bone was formed at all the experimental sites. Autogenous bone graft was confirmed to be superior to xenograft using this sandwich technique. Furthermore, the osteoblastic activities on the sandwich side were seen to be more when compared with the control side (Interceed side). CONCLUSION: The Ogunsalu sandwich bone regeneration technique has been successfully evaluated with SPECT which shows osteoblastic activity with formation of vascularized bone which integrates with the surrounding bone.

Single photon emission computerized tomography and histological evaluation in the validation of a new technique for closure of oro-antral communication: an experimental study in pigs.

Various bone regeneration techniques have evolved recently but controversies regarding vascularization and integration of such bone grafting techniques have led occasionally to animal experiment to validate such techniques. The objective of this study was to evaluate the evidence of vascularization and osseo-integration of a new bone regeneration technique utilized for the closure of oro-antral communication (OAC) by an experimental model in which Single Photon Emission computerized Tomography and histological studies were conducted in pigs. We conclude that the sandwich technique used for the closure of OAC results in a vascularized new bone formation which eventually osseo-integrate with the surrounding bone. Also, this experimental study confirmed that autogeneous bone graft was superior to xenografts when used within the sandwich unit.

Odontogenic keratocyst in Jamaica: a review of five new cases and five instances of recurrence together with comparative analyses of four treatment modalities.

AIM: Five new cases of odontogenic keratocyst (OKC) together with five instances of recurrence are reviewed with special emphasis on radiology and surgical management. A comparative analysis offour different treatment modalities used in the treatment of OKC in these patients (new and recurrent cases) is reported. SUBJECTS AND METHODS: The case notes and radiographs ofpatients who had histological confirmation of OKC at both the Cornwall Regional Hospital and Kingston Public Hospital in Jamaica were reviewed for demographics, radiological presentation, treatment modalities and outcome of treatment. Cases of recurrence were separated from new cases. This study was conducted for the period 1980 to 2004. RESULTS: Five new cases and five instances of recurrence were documented over the 25-year period The new cases of OKC keratocyst accounted for 1.71% of the total jaw bone tumours and 12% of OKC keratocysts over the first 16 years. The posterior mandible appears to be the most favoured site. Of significance, one case of nevoid basal cell carcinoma syndrome (NBCCS) and a case of ameloblastomatous transformation in the wall of an OKC keratocyst were recorded The age range of the new cases was 12 to 44 years. CONCLUSION: The radiological finding from this review is similar to previous reports. However the authors record a unique and historic case of ameloblastomatous transformation of OKC. A case of OKC in NBCCS is also documented Of all four surgical treatment modalities compared, only cryosurgery was promising, so far with no recurrence after a follow-up period of six years.

Radiological assessment of type II Stafne idiopathic bone cyst in a patient undergoing implant therapy: a case report.

This paper is intended to describe the confirmative role of radiology in the diagnosis of Stafne Idiopathic bone Cyst (SIBC) without the need for histopathology especially when dental implants are considered so as to avoid unnecessary invasive surgical exploration of this benign pathology. Other pathologies may present not unlike SIBC and as such it is mandatory to rule out such possibilities especially prior to dental implant therapy. The use of orthopanthomogram and non-sialographic computed tomography (CT) scan in the reported case together with a review of CT scan confirmatory role in the diagnosis of SIBC from the literature was the basis for this clinical report. Based on the CTscan findings of the jaw in this case and review of the literature, the implant procedure was commenced without the need of histopathology and/or for invasive surgical exploration of this pathology. All pathologic lesions of the jawbone seen on the orthopanthomogram should be confirmed prior to commencement of implant procedure even when such pathologies are seen in areas remote from the proposed implant site. The pre-implant radiological assessment utilizing non-sialographic CT scan alone is confirmatory of SIBC.

A new radiological classification for ameloblastoma based on analysis of 19 cases.

OBJECTIVE: To describe ameloblastoma of the jawbone in young Jamaicans, with special emphasis on radiological findings, and to introduce a radiological classification which could assist in the categorization of these cases according to their biological behaviour and hence their subsequent surgical and medical management. SUBJECTS AND METHODS: The series comprised all the 18 cases of ameloblastoma of the jaw seen in patients under the age of 20 years in the two major hospitals in Jamaica with an oral and maxillofacial surgery department from 1980 to 1995. Radiological and histological diagnosis was confirmed in all. A case of maxillary ameloblastoma in a 13-year old girl seen in the year 2000 was also included in this study. This last case had special attributes. RESULTS: All 19 patients had primary lesions of ameloblastoma. The mean age was 16.1 years with a mode of 18 years and a range of 13 to 19 years. The male to female ratio was 1.1:1. Eighteen cases were seen in the mandible and one case in the maxilla. Of these, 42% were unilocular and 58% were multilocular radiologically. Thirty-two per cent of cases had unerupted teeth associated with the lesions and 32% had root resorption. Based on our new radiological classification, the most predominant radiological type was IIb2 with root resorption (42%). There was no radiological type classically simulating dentigerous cyst (Ia2). CONCLUSION: Ameloblastoma in young Jamaicans presented more in the adolescent period and are predominantly unicystic and rare in the maxilla. A new classification for ameloblastoma based solely on radiological presentation is adopted.

A new surgical management for oro-antral communication: the resorbable guided tissue regeneration membrane--bone substitute sandwich technique.

This paper describes a new technique for the closure of oro-antral fistula/communication, in which both hard tissue (bone) and soft tissue closure is achieved. The sandwich technique utilizes a suitable bone grafting material sandwiched between two sheaths of Biogide (a resorbable membrane) for the hard tissue closure of oro-antral communication post traumatic exodontia. The bone grafting material utilized for this case was Bio-oss. The result obtained was excellent with regeneration of sufficient bony tissue to allow placement of an endosseous implant. This sandwich technique is a simple and excellent technique for the closure of oro-antral communication, especially when subsequent placement of endosseous implant is considered without the need of donor site surgery for bone grafting. The otorhinolaryngologists and oral and maxillofacial surgeons should find this technique very useful in the closure of oro-antral fistulae.

Cemento-osseous dysplasia in Jamaica: review of six cases.

Six cases of cemento-osseous dysplasia (COD) of the jaw bone in Jamaicans are reviewed. Five were documented over a 15-year period (1980-1995). These include a case of florid cemento-osseous dysplasia (previously called gigantiform cementoma). Three of the initial cases were histologically diagnosed as gigantiform cementoma. There was no indication in the patient's case file whether these were familial or non-familial. The other two cases were diagnosed histologically as periapical cemento-osseous dysplasia and cementoblastoma respectively. Based on the current understanding of the nature of florid-cemento-osseous dysplasia (FLCOD), a new case was diagnosed as such solely on radiological findings. This single case of FLCOD is reported and discussed against the background of other cemento-osseous lesions. Special emphasis is placed on the radiology of COD in this paper. The confirmative role of radiology without the need for histophathology and treatment for asymptomatic FLCOD is emphasized.

Aggressive infantile (desmoid-type) fibromatosis of the maxilla: a case report and new classification.

This paper describes the clinical, radiographic and histologic findings of an aggressive infantile (desmoid-type) fibromatosis of the face in a seven-year-old black Jamaican male. This condition is rare in the head and neck region and its occurrence in the maxilla is exceptional. The differential diagnosis, management and long term follow-up of this case are also mentioned The need for a less aggressive surgical management in this child and long-term follow-up is stressed. Also, its occurrence in someone of African descent has not been reported previously. The absence of recurrence, eight years after surgery is significant. This paper discusses the differential diagnosis and treatment of aggressive infantile fibromatosis and suggests a classification of the condition.

Non-syndromal multiple buried supernumerary teeth: report of two cases from the English-speaking Caribbean and a review of the literature.

Multiple supernumerary teeth affecting all four quadrants of the jaw are a rare dental anomaly which has become a chance finding on routine dental panoramic tomography (DPT). In this paper, two cases from the English-speaking Caribbean are reported. The role of radiography in the diagnosis and management of this rare developmental dental anomaly is emphasized. The paper stresses the importance of ruling out associated syndromes such as Gardner's Syndrome, cleidocranial dysostosis and cleft lip and palates, as multiple supernumerary teeth are usually related to such conditions. There is a review of the literature as it relates to supernumerary teeth.

Familial tarda type osteogenesis imperfecta with dentinogenesis imperfecta Type I. Case report.

This paper presents a case of dentinogenesis imperfecta Type I occurring in a patient with familial tarda type osteogenesis imperfecta. The investigation and management of this patient is described.

Anaphylactic reaction following administration of lignocaine hydrochloride infiltration. Case report.

A case of progressive anaphylactoid reaction complicating a local anaesthetic agent administered to a dental patient is described. The management of the condition is discussed.