The present study was carried out to evaluate the osteoconductive nature of Bio-OssRTM (natural deproteinized bone mineral) when used as an onlay bone substitute in a Guided Bone Regeneration model. The lateral surface of the mandible was exposed bilaterally, in 8 rabbits. On one side of the mandible, two titanium chambers were filled with Bio-OssRTM material and the chambers were then firmly secured to the mandible using screws. The pores in the titanium chambers were covered with a layer of Bio-GideRTM material. On the opposite side of the mandible, chambers without Bio-OssRTM were placed on the lateral side of the mandible as a control. After a healing period of 3 months, histologic sections were obtained from each chamber. It was observed that new bone was generated in both test and control chambers to various degrees. In the test group, the newly generated bone was 18.41% and in the control group it was 5.31%. This difference was statistically significant. Thus, in this experiment, Bio-OssRTM was proven to be osteoconductive.

Objective. The objective of this study is to test the efficacy of the biodegradable mesh as an alternative fixation device to the titanium mesh for support of onlay particulate, bone and cancellous, marrow (PBCM) grafts. Two parameters were evaluated: (1) Bone graft volume maintenance; and (2) Calcified tissue surface area and distribution. Methods. 12 New Zealand white rabbits were used and divided equally into two groups. In both groups, endochondral, cancellous bone graft was harvested from the anterior ilium. The bone graft was then compressed and placed as an onlay onto the lateral aspect of the mandible using two chambers for each animal. In the control group, the chambers were made of titanium, however in the test group the chambers were made of poly L-lactide, polyglycolide and trimethylene carbonate mesh (Inion GTR(TM) Finland), and thereafter the chambers were fixed to the mandible. The animals were then sacrificed after eight weeks postoperatively, and then Micro-CT imaging was performed for the entire sample in order to determine the total volume of calcified tissue present under each chamber. In addition, Histologic sections were obtained from each chamber, and thereafter stained using Toluidine blue and Von Kossa for the purpose of histomorphometric analysis in order to determine the calcified tissue surface area. Results. When comparing the data from both the titanium (Ti) and the biodegradable mesh (PLA) groups, Micro CT analysis showed no significant statistical difference (P-value = 0.546) with regard to the percentage of bone found under the chambers (Ti 15.0% and PLA 13.83%). Interestingly, neither did the histomorphometric analysis show any significant statistical deference (P-value = 0.8272) with regard to the percentage of calcified tissue surface area (Ti 16.86% and PLA 16.17%). Moreover, this calcified tissue was also found to be evenly distributed in both groups. Conclusion. Biodegradable mesh made of poly L-lactic and polyglycolic acid copolymers appears to be an appropriate alternative to the Ti mesh for support of PBCM bone grafts. However, further clinical trails should be conducted to confirm these findings.

No description available.

No description available.

INTRODUÇÃO: A ressecção do ramo ascendente da mandíbula foi, durante várias décadas, considerada o tratamento de eleição para os tumores da loja amigdalina e região retromolar, independente do grau de acometimento do osso mandibular, ocasionando um déficit funcional e estético considerável, muitas vezes, com prejuízos irreparáveis à qualidade de vida, às vezes desnecessário. Assim, a ressecção marginal do osso mandibular surgiu como uma alternativa de tratamento viável, uma vez que a manutenção de um segmento do ramo mandibular, em lesões sem comprometimento ósseo, não aumenta os índices de recidiva, tampouco compromete os princípios de radicalidade oncológica. OBJETIVO E MÉTODOS: Por meio de estudo retrospectivo de Outubro de 1994 a Dezembro de 2001, foram comparados 42 pacientes portadores de tumores avançados de região retromolar e loja amigdalina, sendo 20 deles submetidos a ressecção marginal do osso mandibular e 22 submetidos a ressecção do ramo ascendente da mandíbula, em relação a complicações, seqüela de procedimentos, recidiva locorregional e sobrevida. RESULTADOS: Dos 20 pacientes tratados com mandibulectomia marginal, avaliados por um período de 9 a 60 meses, sete (35%) pacientes morreram com doença, com sobrevida mínima de 09 meses, 3 por recidiva local, 3 por recidiva regional e 1 por recidiva locorregional. Um paciente morreu no pós-operatório imediato. Na avaliação da peça cirúrgica encontramos todas as margens livres, considerada exígua em profundidade em dois pacientes, um deles falecido por recidiva local. Houve disseminação linfonodal em 15 pacientes sendo com ruptura extracapsular em 4, encontrada em 2 pacientes com recidiva regional. O controle locorregional foi obtido em 63% dos pacientes. Dos 22 pacientes tratados com ressecção segmentar do osso mandibular, com intervalo de seguimento de 14 a 60 meses, 8 (36,4%) morreram pela doença, com sobrevida mínima de 9 meses, 5 por recidiva local e 3 por recidiva à distância. Um paciente morreu no pós-operatório imediato. As margens foram livres em 20 pacientes e, em 3 exíguas, um deles falecido por recidiva local. Houve disseminação linfonodal em 12 pacientes com ruptura extracapsular em 7 pacientes. O controle locorregional foi obtido em 61% dos pacientes. Na curva de análise de sobrevida, pelo método de Kaplan-Meier, o grupo tratado com mandibulectomia marginal apresentou uma taxa de 42%, com intervalo de 31 a 52 meses, erro padrão de 5 meses e intervalo de confiança de 95% e o grupo tratado com ressecção segmentar 38% com intervalo de 27 a 48 meses, erro padrão de 5 meses, um intervalo de confiança de 95%. A comparação pelo teste de Log Rank, não paramétrico apresentou p<0,8329 e pelo teste t-Student p< 0,621 ambos não significantes. As principais complicações foram a infecção local em 5 (11,9%) pacientes e a fístula orocutânea em 4 (9,5%). Houve uma fratura da placa de titânio, dois pacientes evoluíram com osteorradionecrose e nove com disfunção da articulação têmporo-mandibular. CONCLUSÕES: Não houve diferenças estatisticamente significantes entre os grupos de ressecção marginal e segmentar nos critérios analisados. Portanto, a conservação do ramo ascendente da mandíbula, em lesões que não apresentem envolvimento mandibular, mesmo avançadas, não aumenta o índice de recidiva. / INTRODUCTION: For several decades, resection of the ascending ramus of the mandible was considered to be mandatory for the treatment of tonsil and retromolar trigone tumours, independent from the damage degree of the mandibular bone, causing considerable functional and aesthetic deficit, many times with irreparable quality of life loss, sometimes unnecessary. Thus, marginal resection of the mandibular bone appeared as a feasible alternative treatment, since maintaining a segment of the mandibular ramus in lesions without bone involvement did not increase the recurrence indexes or compromise the principles of oncological radicalness. OBJECTIVES AND METHODS: Through a retrospective study from October 1994 to December 2001, 42 patients with advanced retromolar and tonsil tumors were compared, 20 undergoing marginal resection of the mandibular bone and 22 undergoing segmental resection of the ascending ramus of the mandible, with regard complications, injury originated from the procedure, locoregional recurrence and survival. RESULTS: From the 20 patients undergoing to marginal mandibulectomy, assessed for a period of 09 to 60 months, seven (35%) patients died of the disease, with a minimal survival of 9 months: 3 due to local recurrence, 3 due to regional recurrence and 1 due to local and regional recurrence. One patient died in the immediate postoperative period. When assessing the surgical part, all the margins were found to be free and in two patients, were considered to be of little depth, one of them being found in one of the patients that died from local recurrence. There was lymph nodal dissemination in 15 patients, with capsular rupture in 4, of which two presented regional recurrence. The locoregional control was obtained in 63% of the patients. From the 22 patients undergoing to segmental resection of the mandibular bone, with a follow-up varying from 14 to 60 months, 8 (36.4%) died of the disease, with a minimum survival of 9 months, 5 due to local recurrence and 3 due to distant recurrence. One patient died in the immediate postoperative period. The surgical margins were considered free from disease in 20 patients and, in three they were too small, one patient died of local recurrence. There was lymph nodal dissemination in 12 patients, and 7 presented capsular rupture. The locoregional control was obtained in 61% of the patients. In the survival analysis curve, by the Kaplan-Meier method, the group submitted to marginal mandibulectomy presented with a rate of 42%, with an interval of 31 to 52 months, standard error of 5 months and confidence interval of 95%, and the group submitted to segmentary resection, 38% with an interval of 27 to 48 months, a standard error of 5 months, and a confidence interval of 95%. The comparison using the non-parametric Log-Rank test presented p<0.8326 and the t-Student test p< 0.621, both not statistically significant. The main complications were local infection in 5 (11.9%) patients and oro-cutaneous fistula in 4 (9.5%). There was one titanium plate fracture, two patients developed osteoradionecrosis and nine temporo-mandibular dysfunction. CONCLUSIONS: There weren t statistically significant differences between the marginal and the segmental resection groups in relation to the analyzed criteria. So, the preservation of the ascending ramus of the mandible, in lesions which do not present mandible commitment, even if not advanced, doesn t increase the recurrence rate.

Embora existam muitos estudos clínicos avaliando analgésicos e o controle da dor em cães, poucos são realizados em animais com dor do câncer e submetidos a procedimento cirúrgico para ressecção da neoplasia como a maxilectomia e mandibulectomia. Este estudo clínico foi realizado de forma prospectiva, comparativa, aleatória e de maneira simples cego com o propósito de avaliar a eficácia analgésica de diferentes tratamentos no período pós-operatório em cães submetidos à maxilectomia ou mandibulectomia. Foram utilizados no estudo 42 cães com neoplasia oral. Todos os animais foram prémedicados com acepromazina (0,05mg/kg) associado à meperidina (2mg/kg) por via intramuscular e a anestesia foi induzida com propofol por via iv na dose suficiente realizar a intubação (2.3-6.5mg/kg). O isoflurano foi utilizado para a manutenção da anestesia. Trinta minutos antes do fim do procedimento cirúrgico, os cães foram distribuídos aleatoriamente em um dos 5 diferentes grupos para analgesia pósoperatória: tramadol 2mg/kg (Tra), codeína 2mg/kg (Co), cetoprofeno 2mg/kg (Ce), tramadol 2mg/kg associado ao cetoprofeno 2mg/kg (TraCe) ou codeína 2mg/kg associado ao cetoprofeno 2mg/kg (CoCe), por via subcutânea. A freqüência cardíaca (FC) e respiratória (FR), pressão arterial sistólica (PAS), pressão arterial diastólica (PAD) e pressão arterial média (PAM), glicose sanguínea, cortisol e interleucina-6 (IL- 6) e grau de sedação foram verificados até 24 horas, e grau de analgesia foi verificado por até 120 horas do início da administração do analgésico, ou seja, os respectivos tratamentos foram mantidos por 5 dias da seguinte forma: tramadol ou codeína a cada 8 horas e cetoprofeno a cada 24 horas por via oral (MBL, M1, M2, M3, M4, M5, M24, M48, M72, M96 e M120). O resgate analgésico foi realizado nos animais que apresentaram escore de dor 4 em qualquer momento do estudo (dipirona 25mg/kg e morfina 0,1mg/kg). A análise estatística foi realizada por meio do Kruskal-Wallis, Friedman para mensurações repetidas, ANOVA e teste 2. Os gráficos em boxplot ou diagrama em caixas representam a distribuição dos dados. Os valores com p<0,05 foram considerados significantes. Não houve diferença entre os grupos de tratamento com relação ao peso, tempo de cirurgia, tempo para extubação, FC, FR, PAS, PAD e PAM, cortisol e IL-6 séricos, e escore de dor pela escala de análise descritiva. A concentração da glicose sanguínea aumentou de forma significante com relação aos valores basais no grupo Tra (M5= 96±14), Co (M1= 120±66 e M3=96±21), Ce (M5= 105±22) e CoCe (M3=104±16). Aumento do escore de dor foi observado no M2 do grupo Tra em relação a MBL e M1 a M5 do grupo Co em relação a M120 (p<0,05), contudo a média do escore não foi maior que 2,7. Baixo grau de sedação ainda foi observado no grupo CoCe no M24 (0,1±0,4 p<0,001) com relação ao M1. O número de resgate foi baixo, totalizando 19 administrações. No grupo Ce houve maior necessidade de resgate analgésico. Com base nos resultados obtidos, pôde-se concluir que os grupos de tratamento analgésico promoveram controle da dor pós-operatória de boa qualidade na maioria dos cães do estudo e com baixa incidência de efeitos adversos, podendo ser indicados no controle da dor em procedimentos de maxilectomia e mandibulectomia. / Although there are many clinical studies evaluating analgesics and pain control in dogs, very few were carried out in animals with cancer pain, and submitted to oncologic surgery with tumor resections such as maxillectomy and mandibulectomy. This clinical, prospective, randomized, simple blinded study was performed with the purpose of evaluating analgesic efficacy of different treatments in the postoperative period in dogs submitted to maxillectomy or mandibulectomy. Forty-two client-owned dogs with oral tumor were used in the study. Dogs were premedicated with acepromazine (0.05mg kg-1) and meperidine (2mg kg-1) by the intramuscular route and anesthesia was induced with intravenous propofol in a dose sufficient to allow intubation (2.3-6.5mg-1). Isoflurane was used for maintenance of anesthesia. Thirty minutes prior to the end of surgery, dogs were randomly allocated in one of 5 different groups for postoperative analgesia: tramadol 2mg kg-1 (Tra), codeine 2mg kg-1 (Co), ketoprofen 2mg kg-1 (Ke), tramadol 2mg kg-1 + ketoprofen 2mg kg-1 (TraKe) or codeine 2mg kg-1 + ketoprofen 2mg kg-1 (CoKe), subcutaneously. Heart (HR) and respiratory (RR) rates, systolic (SBP), median (MBP) and diastolic (DBP) blood pressures, blood glucose, serum cortisol and interleukin-6 (IL-6) and degree of sedation were recorded for 24 hours, and degree of analgesia were evaluated until 120 hours of the start of analgesic administration (MBL, M1, M2, M3, M4, M5, M24, M48, M72, M96 and M120), being that treatments were maintained for 5 days as follows: codeine or tramadol every 8 hours and the ketoprofen every 24 hours orally. Analgesic rescue was delivered to animals with pain scores equal or superior to 4 at any time of the study (dypirone 25mg -1 and morphine 0,1mg-1). Statistical analyses were performed by means of the Kruskal-Wallis, Friedmann for repeated measures, ANOVA and 2 tests. Graphics boxplot or box diagrams represents dates of distribution. Values of p<0.05 were considered significant. There were no differences between groups related to weight, surgical time, extubation time, HR, RR, SBP, MBP, DBP, serum cortisol and IL-6, and pain score by Descriptive Scale (DS). Blood glucose concentrations were significantly increased in relation to baseline, in groups Tra (M5= 96±14), Co (M1= 120±66 e M3=96±21), Ke (M5= 105±22) and CoKe (M3=104±16). Increase of pain score was observed in M2 of group Tra in relation to baseline, and M1 to M5 of group Co in relation to M120 (p<0,05), however the average score was not higher than 2.7. Low level of sedation was also observed in group CoKe in M24 (0.1 ± 0.4 - p <0.001) compared to M1.. The number of rescue was low, totaling 19 administrations. Ke group required more analgesic rescue. So, it can be conclude that treatment analgesic groups promoted a good quality pain control of postoperative in most of the dogs in the study and with low incidence of side effects, could be indicated in the control of the pain in procedures of maxillectomy and mandibulectomy.

下颌角缩小术是一种非常流行、有效、并广泛用于修饰脸部轮廓的手术方式。手术中所用到的主要工具有往复锯和圆头磨钻，这两种手术工具工作时有一个共同的特点：通过其高速运转去除骨质。缺乏经验的医生通常需要较长周期的训练，来学习和熟悉如何操作这两种手术工具，并在操作过程中避免由于无法控制好工具与骨骼的触碰以及工具运转时的在骨骼上的移动所造成的危险。具有视觉和触觉反馈的虚拟手术模拟系统为医生们练习手术技巧提供了一种可行并且安全的方式。然而，创建高速运转的手术工具与坚硬的骨骼之间的真实触觉交互模型是一个非常有挑战性的任务。 / 这篇论文设计并实现了虚拟下颌角缩小手术模拟系统，并且创建高保真度的视觉和触觉反馈来增强虚拟手术环境的真实性。文章提出了基于冲量理论的力反馈模型用来模拟作用在工具上的碰撞力和力矩。在不同的往复速率或者旋转速度的情况下，所提出的模型都可以为医生提供可信真实的力感反馈。并且针对磨钻在磨骨是震动明显对磨骨操作有较大影响的特点，论文还提出了一个三维震动模型来模拟磨骨时作用在钻轴上的橫向震动和轴向震动。同时，论文还提出了用于模拟手术中骨质去除以及重建的实时绘制方法。为了验证力模型的真实性，我们还创建了机械平台，采集磨骨和截骨过程中产生的真实力数据，从而用来与虚拟手术中产生的力数据进行比较。最后，还引入真实病人的CT扫描数据来对虚拟手术系统进行实证研究，评估创建的系统是否可以用于训练具有不同手术经验的医生。实证研究的结果也验证了所提出的虚拟手术系统的有效性。 / Mandibular angle reduction is a popular and efficient procedure widely used to alter the facial contour. The primary surgical instruments, the reciprocating saw and the round burr, employed in the surgery have a common feature: operating at a high-speed. Generally, inexperienced surgeons need a longtime practice to learn how to minimize the risks caused by the uncontrolled contacts and cutting motions in manipulation of instruments with high-speed reciprocation or rotation. Virtual reality (VR)-based surgical simulations with both visual and haptic feedbacks provide novice surgeons with a feasible and safe way to practise their surgical skill. However, creating realistic haptic interactions between a high-speed rotary or reciprocating instrument and stiff bone is a challenging task. In this work, a virtual reality-based surgical simulator for the mandibular angle reduction was designed and implemented. High-fidelity visual and haptic feedbacks are provided to enhance the perception in a realistic virtual surgical environment. The impulse-based haptic model was proposed to simulate the contact forces and torques on the instruments. It provides convincing haptic sensation for surgeons to control the instruments under different reciprocation or rotation velocities. Also, in order to mimic the lateral and axial burring vibration forces, a three dimensional vibration model has been developed. The real-time methods for bone removal and reconstruction during surgical procedures have been proposed to support realistic visual feedbacks. The simulated contact forces were verified by comparing against the actual force data measured through the constructed mechanical platform. An empirical study based on the patient-specific data was conducted to evaluate the ability of the proposed system in training surgeons with various experiences. The results confirm the validity of our simulator. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Wang, Qiong. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 100-114). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Abstract --- p.i / Acknowledgement --- p.v / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Contributions of the Thesis --- p.5 / Chapter 1.2 --- Thesis Roadmap --- p.7 / Chapter 2 --- Related Work --- p.9 / Chapter 2.1 --- Virtual Orthopaedic Surgical Simulator --- p.9 / Chapter 2.2 --- Haptic Rendering for Virtual Surgery --- p.11 / Chapter 2.3 --- Evaluation of the Virtual System --- p.14 / Chapter 3 --- System Design --- p.17 / Chapter 3.1 --- Overall System Framework --- p.17 / Chapter 4 --- Bone-burring Surgical Simulation --- p.21 / Chapter 4.1 --- Impulse-Based Modeling of Haptic Simulation of Bone-Burring --- p.22 / Chapter 4.1.1 --- Basic Assumptions --- p.22 / Chapter 4.1.2 --- Bone-Burring Contact Description --- p.25 / Chapter 4.1.3 --- Burring Force Modeling --- p.29 / Chapter 4.2 --- Simulation of Bone Removal --- p.41 / Chapter 4.2.1 --- Bone Removal model --- p.41 / Chapter 4.2.2 --- Adaptive Subdividing Removal Surface --- p.42 / Chapter 4.3 --- Implementation and Experimental Results --- p.52 / Chapter 4.3.1 --- Force Evaluation --- p.53 / Chapter 4.3.2 --- Task-based Evaluation --- p.57 / Chapter 4.3.3 --- Time Performance --- p.61 / Chapter 5 --- Bone-sawing Surgical Simulation --- p.64 / Chapter 5.1 --- Impulse-Based Modeling of Haptic Simulation of Bone-Sawing --- p.65 / Chapter 5.1.1 --- Haptic Saw Instruments Description --- p.65 / Chapter 5.1.2 --- Sawing Force Modeling --- p.67 / Chapter 5.1.3 --- Sawing Torque Constraint --- p.70 / Chapter 5.2 --- Real-time Bone Mesh Reconstruction --- p.74 / Chapter 6 --- Evaluation --- p.78 / Chapter 6.1 --- Haptic Feedback Evaluation --- p.79 / Chapter 6.1.1 --- Mechanical Platform Setup --- p.79 / Chapter 6.1.2 --- Comparison of The Measured and Simulated forces --- p.81 / Chapter 6.2 --- Empirical Study --- p.85 / Chapter 6.2.1 --- Patient Specific Data --- p.87 / Chapter 6.2.2 --- Objective Performance Metrics --- p.89 / Chapter 6.2.3 --- Evaluation Results --- p.90 / Chapter 7 --- Conclusion --- p.94 / Publication List --- p.98 / Bibliography --- p.100

INTRODUÇÃO: A ressecção do ramo ascendente da mandíbula foi, durante várias décadas, considerada o tratamento de eleição para os tumores da loja amigdalina e região retromolar, independente do grau de acometimento do osso mandibular, ocasionando um déficit funcional e estético considerável, muitas vezes, com prejuízos irreparáveis à qualidade de vida, às vezes desnecessário. Assim, a ressecção marginal do osso mandibular surgiu como uma alternativa de tratamento viável, uma vez que a manutenção de um segmento do ramo mandibular, em lesões sem comprometimento ósseo, não aumenta os índices de recidiva, tampouco compromete os princípios de radicalidade oncológica. OBJETIVO E MÉTODOS: Por meio de estudo retrospectivo de Outubro de 1994 a Dezembro de 2001, foram comparados 42 pacientes portadores de tumores avançados de região retromolar e loja amigdalina, sendo 20 deles submetidos a ressecção marginal do osso mandibular e 22 submetidos a ressecção do ramo ascendente da mandíbula, em relação a complicações, seqüela de procedimentos, recidiva locorregional e sobrevida. RESULTADOS: Dos 20 pacientes tratados com mandibulectomia marginal, avaliados por um período de 9 a 60 meses, sete (35%) pacientes morreram com doença, com sobrevida mínima de 09 meses, 3 por recidiva local, 3 por recidiva regional e 1 por recidiva locorregional. Um paciente morreu no pós-operatório imediato. Na avaliação da peça cirúrgica encontramos todas as margens livres, considerada exígua em profundidade em dois pacientes, um deles falecido por recidiva local. Houve disseminação linfonodal em 15 pacientes sendo com ruptura extracapsular em 4, encontrada em 2 pacientes com recidiva regional. O controle locorregional foi obtido em 63% dos pacientes. Dos 22 pacientes tratados com ressecção segmentar do osso mandibular, com intervalo de seguimento de 14 a 60 meses, 8 (36,4%) morreram pela doença, com sobrevida mínima de 9 meses, 5 por recidiva local e 3 por recidiva à distância. Um paciente morreu no pós-operatório imediato. As margens foram livres em 20 pacientes e, em 3 exíguas, um deles falecido por recidiva local. Houve disseminação linfonodal em 12 pacientes com ruptura extracapsular em 7 pacientes. O controle locorregional foi obtido em 61% dos pacientes. Na curva de análise de sobrevida, pelo método de Kaplan-Meier, o grupo tratado com mandibulectomia marginal apresentou uma taxa de 42%, com intervalo de 31 a 52 meses, erro padrão de 5 meses e intervalo de confiança de 95% e o grupo tratado com ressecção segmentar 38% com intervalo de 27 a 48 meses, erro padrão de 5 meses, um intervalo de confiança de 95%. A comparação pelo teste de Log Rank, não paramétrico apresentou p<0,8329 e pelo teste t-Student p< 0,621 ambos não significantes. As principais complicações foram a infecção local em 5 (11,9%) pacientes e a fístula orocutânea em 4 (9,5%). Houve uma fratura da placa de titânio, dois pacientes evoluíram com osteorradionecrose e nove com disfunção da articulação têmporo-mandibular. CONCLUSÕES: Não houve diferenças estatisticamente significantes entre os grupos de ressecção marginal e segmentar nos critérios analisados. Portanto, a conservação do ramo ascendente da mandíbula, em lesões que não apresentem envolvimento mandibular, mesmo avançadas, não aumenta o índice de recidiva. / INTRODUCTION: For several decades, resection of the ascending ramus of the mandible was considered to be mandatory for the treatment of tonsil and retromolar trigone tumours, independent from the damage degree of the mandibular bone, causing considerable functional and aesthetic deficit, many times with irreparable quality of life loss, sometimes unnecessary. Thus, marginal resection of the mandibular bone appeared as a feasible alternative treatment, since maintaining a segment of the mandibular ramus in lesions without bone involvement did not increase the recurrence indexes or compromise the principles of oncological radicalness. OBJECTIVES AND METHODS: Through a retrospective study from October 1994 to December 2001, 42 patients with advanced retromolar and tonsil tumors were compared, 20 undergoing marginal resection of the mandibular bone and 22 undergoing segmental resection of the ascending ramus of the mandible, with regard complications, injury originated from the procedure, locoregional recurrence and survival. RESULTS: From the 20 patients undergoing to marginal mandibulectomy, assessed for a period of 09 to 60 months, seven (35%) patients died of the disease, with a minimal survival of 9 months: 3 due to local recurrence, 3 due to regional recurrence and 1 due to local and regional recurrence. One patient died in the immediate postoperative period. When assessing the surgical part, all the margins were found to be free and in two patients, were considered to be of little depth, one of them being found in one of the patients that died from local recurrence. There was lymph nodal dissemination in 15 patients, with capsular rupture in 4, of which two presented regional recurrence. The locoregional control was obtained in 63% of the patients. From the 22 patients undergoing to segmental resection of the mandibular bone, with a follow-up varying from 14 to 60 months, 8 (36.4%) died of the disease, with a minimum survival of 9 months, 5 due to local recurrence and 3 due to distant recurrence. One patient died in the immediate postoperative period. The surgical margins were considered free from disease in 20 patients and, in three they were too small, one patient died of local recurrence. There was lymph nodal dissemination in 12 patients, and 7 presented capsular rupture. The locoregional control was obtained in 61% of the patients. In the survival analysis curve, by the Kaplan-Meier method, the group submitted to marginal mandibulectomy presented with a rate of 42%, with an interval of 31 to 52 months, standard error of 5 months and confidence interval of 95%, and the group submitted to segmentary resection, 38% with an interval of 27 to 48 months, a standard error of 5 months, and a confidence interval of 95%. The comparison using the non-parametric Log-Rank test presented p<0.8326 and the t-Student test p< 0.621, both not statistically significant. The main complications were local infection in 5 (11.9%) patients and oro-cutaneous fistula in 4 (9.5%). There was one titanium plate fracture, two patients developed osteoradionecrosis and nine temporo-mandibular dysfunction. CONCLUSIONS: There weren t statistically significant differences between the marginal and the segmental resection groups in relation to the analyzed criteria. So, the preservation of the ascending ramus of the mandible, in lesions which do not present mandible commitment, even if not advanced, doesn t increase the recurrence rate.

Embora existam muitos estudos clínicos avaliando analgésicos e o controle da dor em cães, poucos são realizados em animais com dor do câncer e submetidos a procedimento cirúrgico para ressecção da neoplasia como a maxilectomia e mandibulectomia. Este estudo clínico foi realizado de forma prospectiva, comparativa, aleatória e de maneira simples cego com o propósito de avaliar a eficácia analgésica de diferentes tratamentos no período pós-operatório em cães submetidos à maxilectomia ou mandibulectomia. Foram utilizados no estudo 42 cães com neoplasia oral. Todos os animais foram prémedicados com acepromazina (0,05mg/kg) associado à meperidina (2mg/kg) por via intramuscular e a anestesia foi induzida com propofol por via iv na dose suficiente realizar a intubação (2.3-6.5mg/kg). O isoflurano foi utilizado para a manutenção da anestesia. Trinta minutos antes do fim do procedimento cirúrgico, os cães foram distribuídos aleatoriamente em um dos 5 diferentes grupos para analgesia pósoperatória: tramadol 2mg/kg (Tra), codeína 2mg/kg (Co), cetoprofeno 2mg/kg (Ce), tramadol 2mg/kg associado ao cetoprofeno 2mg/kg (TraCe) ou codeína 2mg/kg associado ao cetoprofeno 2mg/kg (CoCe), por via subcutânea. A freqüência cardíaca (FC) e respiratória (FR), pressão arterial sistólica (PAS), pressão arterial diastólica (PAD) e pressão arterial média (PAM), glicose sanguínea, cortisol e interleucina-6 (IL- 6) e grau de sedação foram verificados até 24 horas, e grau de analgesia foi verificado por até 120 horas do início da administração do analgésico, ou seja, os respectivos tratamentos foram mantidos por 5 dias da seguinte forma: tramadol ou codeína a cada 8 horas e cetoprofeno a cada 24 horas por via oral (MBL, M1, M2, M3, M4, M5, M24, M48, M72, M96 e M120). O resgate analgésico foi realizado nos animais que apresentaram escore de dor 4 em qualquer momento do estudo (dipirona 25mg/kg e morfina 0,1mg/kg). A análise estatística foi realizada por meio do Kruskal-Wallis, Friedman para mensurações repetidas, ANOVA e teste 2. Os gráficos em boxplot ou diagrama em caixas representam a distribuição dos dados. Os valores com p<0,05 foram considerados significantes. Não houve diferença entre os grupos de tratamento com relação ao peso, tempo de cirurgia, tempo para extubação, FC, FR, PAS, PAD e PAM, cortisol e IL-6 séricos, e escore de dor pela escala de análise descritiva. A concentração da glicose sanguínea aumentou de forma significante com relação aos valores basais no grupo Tra (M5= 96±14), Co (M1= 120±66 e M3=96±21), Ce (M5= 105±22) e CoCe (M3=104±16). Aumento do escore de dor foi observado no M2 do grupo Tra em relação a MBL e M1 a M5 do grupo Co em relação a M120 (p<0,05), contudo a média do escore não foi maior que 2,7. Baixo grau de sedação ainda foi observado no grupo CoCe no M24 (0,1±0,4 p<0,001) com relação ao M1. O número de resgate foi baixo, totalizando 19 administrações. No grupo Ce houve maior necessidade de resgate analgésico. Com base nos resultados obtidos, pôde-se concluir que os grupos de tratamento analgésico promoveram controle da dor pós-operatória de boa qualidade na maioria dos cães do estudo e com baixa incidência de efeitos adversos, podendo ser indicados no controle da dor em procedimentos de maxilectomia e mandibulectomia. / Although there are many clinical studies evaluating analgesics and pain control in dogs, very few were carried out in animals with cancer pain, and submitted to oncologic surgery with tumor resections such as maxillectomy and mandibulectomy. This clinical, prospective, randomized, simple blinded study was performed with the purpose of evaluating analgesic efficacy of different treatments in the postoperative period in dogs submitted to maxillectomy or mandibulectomy. Forty-two client-owned dogs with oral tumor were used in the study. Dogs were premedicated with acepromazine (0.05mg kg-1) and meperidine (2mg kg-1) by the intramuscular route and anesthesia was induced with intravenous propofol in a dose sufficient to allow intubation (2.3-6.5mg-1). Isoflurane was used for maintenance of anesthesia. Thirty minutes prior to the end of surgery, dogs were randomly allocated in one of 5 different groups for postoperative analgesia: tramadol 2mg kg-1 (Tra), codeine 2mg kg-1 (Co), ketoprofen 2mg kg-1 (Ke), tramadol 2mg kg-1 + ketoprofen 2mg kg-1 (TraKe) or codeine 2mg kg-1 + ketoprofen 2mg kg-1 (CoKe), subcutaneously. Heart (HR) and respiratory (RR) rates, systolic (SBP), median (MBP) and diastolic (DBP) blood pressures, blood glucose, serum cortisol and interleukin-6 (IL-6) and degree of sedation were recorded for 24 hours, and degree of analgesia were evaluated until 120 hours of the start of analgesic administration (MBL, M1, M2, M3, M4, M5, M24, M48, M72, M96 and M120), being that treatments were maintained for 5 days as follows: codeine or tramadol every 8 hours and the ketoprofen every 24 hours orally. Analgesic rescue was delivered to animals with pain scores equal or superior to 4 at any time of the study (dypirone 25mg -1 and morphine 0,1mg-1). Statistical analyses were performed by means of the Kruskal-Wallis, Friedmann for repeated measures, ANOVA and 2 tests. Graphics boxplot or box diagrams represents dates of distribution. Values of p<0.05 were considered significant. There were no differences between groups related to weight, surgical time, extubation time, HR, RR, SBP, MBP, DBP, serum cortisol and IL-6, and pain score by Descriptive Scale (DS). Blood glucose concentrations were significantly increased in relation to baseline, in groups Tra (M5= 96±14), Co (M1= 120±66 e M3=96±21), Ke (M5= 105±22) and CoKe (M3=104±16). Increase of pain score was observed in M2 of group Tra in relation to baseline, and M1 to M5 of group Co in relation to M120 (p<0,05), however the average score was not higher than 2.7. Low level of sedation was also observed in group CoKe in M24 (0.1 ± 0.4 - p <0.001) compared to M1.. The number of rescue was low, totaling 19 administrations. Ke group required more analgesic rescue. So, it can be conclude that treatment analgesic groups promoted a good quality pain control of postoperative in most of the dogs in the study and with low incidence of side effects, could be indicated in the control of the pain in procedures of maxillectomy and mandibulectomy.