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 / Estudio comparativo de la actividad osteoblástica de dos sistemas de implantes (Endopore versus Entegra) utilizando tomografía computarizada por emisión de fotones individuales: estudio experimental en modelos porcinos

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.

La implantología ha sido un componente importante del tratamiento odontológico durante más de cuarenta años, y durante ese período, se han desarrollado muchas configuraciones de materiales y métodos de implante. A medida que la investigación empírica y clínica proporciona nuevos materiales de implante, ha surgido la necesidad de probar y comparar estos materiales para lograr que los implantes sean lo más costo-efectivos y eficientes posible. La evaluación de la eficiencia de los implantes ha dependido considerablemente de los métodos histológicos y radiológicos, pero estos métodos de medición unidimensional no son útiles a la hora de evaluar la actividad osteoblástica y las propiedades osteointegradoras de los implantes putativos. En este reporte, describimos el uso de la tomografía computarizada por emisión de fotones individuales (SPECT) como herramienta para comparar las capacidades osteointegradoras de dos tipos de implantes.

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 / Aplicaciones emergentes experimentales de la tomografía computarizada por emisión de fotones individuales: un análisis de 16 áreas de interés en el modelo de cerdo

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.

El presente trabajo tiene por objeto dar a conocer varias nuevas aplicaciones de la técnica de la tomografía computarizada por emisión de fotones individuales (inglés SPECT), utilizando modelos de cerdo. Se llevó a cabo una evaluación y el posterior análisis de los resultados de la SPECT en relación con las mandíbulas de ocho cerdos experimentales con un total de 16 áreas de interés. Se evaluaron las varias razones por las que se llevó a cabo cada experimento. Las razones incluyen: i) validación de una nueva técnica de injerto óseo para el cierre de las comunicaciones oroantrales; ii) comparación del injerto óseo autógeno con otros injertos óseos; iii) confirmación secuencial de la actividad osteoblástica de la técnica de regeneración ósea por "sándwich" o membrana inter-posicional con otra técnica; iv) validación del uso de una nueva membrana para la regeneración tisular guiada (RTG); v) validación del hecho que la osteointegración es mejor con implantes porosos que con implantes roscados; y vi) valoración del hecho de que la RTG es esencial para la práctica del implante inmediato. El resultado de esta evaluación se analiza críticamente contra el trasfondo de la evidencia clínica sustancial donde es aplicable, para apreciar la posición de SPECT. Tras la evaluación de 16 áreas de interés en ocho cerdos experimentales, se vio que la SPECT experimental era valiosa para la validación de las razones anteriores. Parece ser una modalidad que puede utilizarse para validar y comparar situaciones que desplegarían actividades osteoblásticas. Se concluye que la gammagrafía ósea refleja las actividades osteoblásticas con precisión, y puede ahora usarse para validar la osteointegración de cualquier implante o sistema de injerto óseo. Esto puede hacerse junto con análisis histológicos y análisis histomorfométicos. Los resultados obtenidos de la tomografía SPECT deben ponerse en correlación con el análisis histológico e histomorfométrico, si estuviese disponible.

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.

Mathematical model for osteobstruction in bone regeneration mechanisms a Headway in skeletal tissue engineering / Modelo matemático de la osteobstrucción en el mecanismo de regeneración del hueso: un avance en la ingeniería del tejido esquelético

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 re-overtaking 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.

En este trabajo se formula un modelo matemático para la evaluación de los parámetros responsables del retardo y la posterior aceleración de la regeneración del hueso en el lado contralateral de la mandíbula de animales experimentales, tras el descubrimiento de un nuevo mecanismo de regeneración del hueso, denominado mecanismo de osteobstrucción de la regeneración del hueso (un mecanismo negativo de regeneración del hueso, el cual contrasta con mecanismos positivos bien establecidos y ampliamente documentados, tales como la osteogénesis, la osteoinducción y la osteoconducción). Este mecanismo osteobstructivo fue demostrado mediante una serie de fenómenos consecutivos en la tomografía computarizada por Emisión de Fotones Individuales (SPECT), tras la evaluación actividades osteoblásticas en experimentos secuenciales con animales, para validar tanto la técnica de sandwich de Ogunsalu (técnica de regeneración de tejidos guiada doble; RTG-D) como la técnica de membrana con interceed (técnica de regeneración de tejidos guiada simple; RTG-S) utilizando SPECT así como evaluaciones histológicas e histomorfométricas. Este trabajo recibe aquí especial atención en términos de análisis matemático, ya que en los experimentos las observaciones no puede realizarse infinitamente. Los modelos matemáticos son pues esenciales para generalizar los resultados de este mecanismo del osteobstructivo de la regeneración ósea. Se utiliza la ecuación de Fisher para describir la movilización de las células óseas durante la regeneración del hueso por dos técnicas diferentes: la técnica de Ogunsalu para la regeneración ósea por "sandwich" (D-GTR) y la técnica S-GTR.

Serum lipids, proteins and electrolyte profiles in rats following total body irradiation / Perfiles de lípidos, proteínas y electrolitos plasmáticos en ratas tras irradiación corporal total

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.

OBJETIVO: Los desequilibrios de lípido y electrolito plasmáticos son comunes en los pacientes críticos sometidos a terapia radioactiva. Aunque los múltiples estados de la enfermedad y la medicación pueden ser responsables del surgimiento de estos trastornos, el objetivo de esta investigación es documentar de manera secuencial el efecto de la radiación corporal total sobre la función corporal, utilizando los cambios secuenciales en los lípidos, electrolitos y proteínas plasmáticos en las ratas. MÉTODOS: Los contenidos de lípidos y proteínas plasmáticos fueron evaluados utilizando kits, en tanto que los electrolitos fueron evaluados mediante fotometría de llama en ratas expuestas a irradiaciones corporales totales de rayos X de 1.27 Gy/min, en dosis cumulativas hasta la cuarta irradiación en intervalos de cinco días. RESULTADOS: El colesterol total y los niveles plasmáticos de triacilgliceroles fueron reducidos significativamente por la irradiación (p < 0.05). No se detectaron diferencias significativas entre; os grupos experimentales y de control en relación con los niveles plasmáticos de colesterol HDL. La concen-tración de electrolito plasmático se mantuvo dentro de los límites normales luego de cada irradiación corporal total de rayos X. La relación sodio/potasio fue significativamente elevada (p < 0.05). La proteína plasmática se elevaba significativamente (p < 0.05) al aumentar la radiación. CONCLUSIÓN: Tras la irradiación corporal total de las ratas normales, seproducen cambios sutiles pero significativos en los lípidos, electrolitos y proteínas del plasma. Estas variaciones podrían ser debidas a reacciones de estrés no específicas, y como tal, son marcadores importantes en el diagnóstico de las lesiones inducidas por la radiación.

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.

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.

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 / Prevalencia y patrón de susceptibilidad antimicrobiana de patógenos aislados de pacientes con periodontitis juvenil en Jamaica: estudio prospectivo multicentro de 15 casos por un período de más de 15 años

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 microorganisms from positive cultures and their antimicrobial susceptibility profile were performed using standard microbiological procedures and dick diffusion (KirbyBauer) methods. Over 80% of the patients were females. The most frequent microorganisms 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 of juvenile 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.

Se estudió la prevalencia y el patrón de susceptibilidad antimicrobiana de los patógenos más frecuentemente aislados de los pacientes tratados por periodontitis juvenil en tres diferentes centros odontológicos en Jamaica de 1989 a 2003. Se tomaron muestras de las bolsas patológicas periodontales de estos pacientes, o de la raíz de la mayor parte de sus dientes, en medio del proceso activo de la enfermedad. Las muestras fueron procesadas en el departamento de Microbiología del Hospital de la Universidad de West Indies, Kingston, Jamaica, y en el laboratorio de Microbiología, Escuela de Medicina Veterinaria, Facultad de Ciencias médicas, Universidad de West Indies, San Agustín, Trinidad y Tobago. La identificación de los microorganismos a partir de cultivos positivos y su perfil de susceptibilidad antimicrobiana, se realizaron mediante procedimientos microbiológicos estándares y métodos de difusión por disco (KirbyBauer). Más del 80% de los pacientes eran mujeres. Los microorganismos más frecuentemente aislados fueron Enterobacter (40,5%), seguido por especies de Klebsiella (19%) y Acinetobacter (10,8%). Actinobacillus actinomycetemcomitans - un patógeno clave ampliamente conocido en enfermedades periodontales juveniles - se encontró sólo en 5,4% (2/37) de los casos en este estudio. Los organismos más frecuentemente aislados mostraban todavía una alta susceptibilidad frente a los antimicrobianos comúnmente usados y disponibles, tales como amoxicilina/clavulanato, trimetoprima/sulfametoxazol, cloranfenicol y los aminoglicósidos. Los patógenos más frecuentemente encontrados en este estudio fueron totalmente diferentes de lo que se obtiene en otros lugares. Es necesario tomar conciencia de los microbios en otros países durante las investigaciones de microbiológicas de la periodontitis juvenil, y no perder vista que la quimioterapia antimicrobiana debe basarse siempre en las pruebas de susceptibilidad. El tratamiento quirúrgico para el desbridamiento mecánico del sitio, así como el injerto óseo con regeneración tisular guiada debería, deben ser obligatorios en conjunción con la quimioterapia antimicrobiana específica.

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 / El ameloblastoma en Jamaica - predominantemente unicístico: análisis de 47 pacientes por un período de más de 16 años y un reporte de caso de criocirugía de reentrada como nueva modalidad de tratamiento para prevenir la recurrencia

OBJECTIVE: To analyse all the cases of ameloblastoma seen in the two major public Hospitals in Jamaica over a 16year 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 10-19year 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. Reentry 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 reentry cryosurgery before recurrence be considered in the management of ameloblastoma for the prevention of recurrence.

OBJETIVO: Analizar todos los casos de ameloblastoma vistos en los dos principales hospitales públicos en Jamaica durante un período de 16 años, y comparar los resultados con la información previamente documentada por otros autores en la literatura. Se describe una nueva modalidad de tratamiento para prevenir la recurrencia del ameloblastoma. SUJETOS Y MÉTODO: Se recuperaron los expedientes de los pacientes diagnosticados histológicamente con ameloblastoma en el Hospital Público de Kingston y el Hospital Regional de Cornwall en Jamaica desde 1980 a 1995, y se obtuvo información documentada acerca de este tumor odontogénico. El análisis reveló que el ameloblastoma unicístico era predominante (95%), en tanto que el ameloblastoma sólido fue de alrededor del 5%. Por lo tanto, no fue sorprendente que la edad promedio en el estudio fuera 29.1 años, con un pico en el grupo etario de 10 a 19 años. No se diagnosticó ningún ameloblastoma periférico. RESULTADOS: Entre 1980 y 1995, se registró un total de 47 nuevos casos de ameloblastoma. Este número representaba el 16.03% de todas las lesiones óseas de mandíbula en Jamaica y 38,2% de las lesiones de hueso de la mandíbula de origen odontogénico durante este período. Estos casos de ameloblastoma representaron el 67% de los tumores odontogénicos con la excepción de los odontomas. La edad promedio fue 29.1 años (rango 13-67). La proporción hombre:mujer fue de 1: 1.14. Sólo tres casos implicaron el maxilar. Resulta particularmente importante el caso del ameloblastoma bilateral sin ninguna continuidad a la región anterior, así como el caso de la participación unilateral de la mandíbula y el maxilar en el mismo paciente. La criocirugía de reentrada (un procedimiento en el cual la criocirugía se realiza después de un período especificado a partir del procedimiento quirúrgico primario) después de la biopsia por escisión de un ameloblastoma quístico del maxilar relativamente pequeño, fue negativa para la recurrencia. CONCLUSIÓN: La manifestación clínicopatológica del ameloblastoma en Jamaica no difiere de lo que ha sido documentado por otros autores en todo el mundo. Sin embargo se reportan dos casos únicos: un caso de ameloblastoma bilateral de la mandíbula y un caso de compromiso unilateral de la mandíbula y el maxilar en el mismo paciente. Sugerimos que se tenga en cuenta la criocirugía de reentrada a la hora de tratar el ameloblastoma para prevenir la recurrencia.

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 / Revisión de seis casos de ameloblastoma maxilar de criocirugía de reentrada de west indies como intervención quirúrgica profiláctica

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 oftumour, radiological features, concurrent involvement ofthe 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 ofthe 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 ofrecurrence for maxillary ameloblastoma. The only case ofmaxillary ameloblastoma that had re-entry cryosurgery continues to benefit from absence ofrecurrence at periodic follow-ups at four years post-primary surgical management (which was enucleation).

El ameloblastoma maxilar es una entidad histopatológica rara. Se examinan un total de seis casos ameloblastoma maxilar en West Indies, histológicamente confirmados. Tres de los casos fueron tomados de un total de 47 ameloblastomas histológicamente confirmados en un periodo de 15 años (1980-1995) en dos unidades maxilofaciales de Jamaica. Otros dos casos proceden de documentación en Jamaica entre 2000 y 2002, uno de los cuales ocurrió en una niña de 13 años (estos dos pacientes tuvieron un seguimiento periódico hasta el 2006). El sexto caso proviene de las historias del departamento maxilofacial de la Universidad de West Indies en Trinidad y Tobago. Este último paciente - en una revisión reciente - presentaba una recurrencia inoperable. Estos casos se examinaron con respecto a los datos demográficos (la edad y el género del paciente), la situación y magnitud de tumor, rasgos radiológicos, compromiso concurrente de la mandíbula, tratamiento con énfasis especial en la modalidad del tratamiento actual y el seguimiento. Los hallazgos no difieren de lo documentado por otros autores de otras partes del mundo. Debido a la anatomía radiográfica del maxilar superior, la recurrencia puede ser detectada tarde, a pesar de que ocurra temprano tras el tratamiento quirúrgico inicial. Es por esta razón que sugerimos la criocirugía de reentrada para prevenir la recurrencia del ameloblastoma maxilar. El único caso de ameloblastoma maxilar que tuvo criocirugía de reentrada continúa beneficiándose de la ausencia de recurrencia en los seguimientos periódicos a cuatro años de tratamiento quirúrgico post-primario (que consistió en una enucleación).

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 / La tomografía computarizada por emisión de fotón único en la evaluación de las actividades osteoblásticas de una nueva técnica de regeneración ósea: análisis de 12 sitios mandibulares en seis cerdos experimentales

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.

OBJETIVOS: Utilizar la tomografía computarizada por emisión de fotón único (TCEFU) realizada en secuencia, a fin de determinar la capacidad óseo-integradora y las actividades osteoblásticas de una nueva técnica de regeneración del hueso, denominada técnica de membrana-sándwich, y comparar la calidad y cantidad de hueso formado por esta unidad de regeneración ósea con la regeneración ósea obtenida mediante el mismo material de injerto de hueso particulado cubierto con interceed® (otro tipo de membrana bioreabsorbible). DISEÑO Y MÉTODO: Mediante TCEFU, se realizó un estudio de imágenes óseas en secuencia, de la mandíbula de un total de 6 cerdos, a los lados izquierdo y derecho (un total de 12 sitios) a las dos horas y media, luego de una inyección de difosfato de metileno marcado con tecnecio 99 m. El examen de imágenes fue realizado usando una cámara gamma Siemens Orbiter tipo II. Los datos de la proyección fueron adquiridos en una matriz de 128 x 128 sobre un arco de 180 y la reconstrucción con TCEFU se realizó usando un método de retroproyección filtrada, con un filtro Shepp-Logan-Hanning y una frecuencia de corte de 0.4. El defecto quirúrgico en un lado de la mandíbula fue tratado con la unidad de sándwich con hueso particulado bio-oss dentro, mientras que el otro lado contenía la misma cantidad de Bio-oss del lado izquierdo, pero cubierto con una membrana de interceed®. La respuesta osteoblástica en el lado con el sándwich clásico fue comparada con el lado del hueso particulado cubierto con la membrana de interceed® en cuanto a actividades fisiológicas dinámicas. La actividad promedio de ambos lados fue calculada y comparada. RESULTADO: En los 12 sitios, las actividades osteoblásticas fueron registradas de forma indicando que se formó hueso vascularizado en todos los sitios experimentales. Se confirmó que el injerto óseo autógeno es superior al xenoinjerto que usa esta técnica de sándwich. Además, se observó que las actividades osteoblásticas en el lado del sándwich eran más en comparación con el lado control (lado del interceed®). CONCLUSIÓN: La técnica de Ogunsalu para la regeneración ósea por "sándwich" o membrana inter-posicional, ha sido exitosamente evaluada mediante TCEFU, concluyéndose que la misma consiste en la actividad osteoblástica con formación de hueso vascularizado que se integra al hueso circundante.

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.

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.