Thesis (M.D.S.)--University of Hong Kong, 1995. / Includes bibliographical references (leaves 174-195).

Thesis (M.D.S.)--University of Hong Kong, 1995. / Includes bibliographical references (leaves 174-195). Also available in print.

published_or_final_version / Dentistry / Master / Master of Dental Surgery

No description available.

No description available.

Magister Chirurgiae Dentium - MChD / Aim: The aim of the study was to investigate whether a correlation exists between the intra- operative position of the Inferior Alveolar Nerve (IAN) and the nerve position as noted on a pre-operative Cone Beam Computer Tomography (CBCT) scan in patients requiring Bilateral Sagittal Split Osteotomy (BSSO) of the mandible. Introduction: The BSSO of the mandible is of fundamental importance in the correction of dental facial deformities. The main post-operative complication of a BSSO of the mandible is Neurosensory Impairment (NSI). To avoid possible NSI it is important to have as much pre- operative information as possible. In this regard, pre-operative CBCT scans can provide the surgeon with an important assessment of the mandibular canal. This information on the buccolingual, superior and inferior position of the canal, especially in the region of the planned osteotomy, could help the surgical team to avoid IAN injury. Materials and Methods: This study correlates the pre-operative position of the IAN as indicated on a CBCT scan with the intra-operative IAN position in patients requiring BSSO of the mandible. Ten standardised cases were included in a prospective case series where twenty mandibular sides were assessed. Results: The variables assessed in this study were location of the nerve, age, sex, type of movement and side of mandible operated on. It was found that only the distance between the Inferior Alveolar Canal (IAC) and the lower border of the mandible are predictive of whether the IAN will be attached to - or free from - the proximal segment of the mandible. Conclusion: From the study it can be concluded that a CBCT scan is a useful and reliable modality in the pre-operative evaluation of patients undergoing BSSO especially with regard to the assessment and mapping of the mandibular canal.

INTRODUCTION: The mental foramen region is important in dental implant placement as it serves as essential neurovascular bed. Despite the belief that the interforaminal area is a safe area for implant placement, a detailed anatomical examination should be done before surgery to prevent injury to the nerve. The inferior alveolar nerve runs outward, upward and backward to the mental foramen and forms the anterior loop of the mental nerve. The anterior loop is the most mesial point of the mental foramen. Methods to determine the extension of the anterior loop include surgical cadaver dissections, panoramic films of markers in dried skulls and cadaver mandibles, panoramic films of patients, periapical radiographs and CT scans of patients. These different methods and dissimilar diagnostic techniques have led to diverse results. The aim of this study was to measure the extension of the anterior loop of the mental foramen by using cone-beam computed tomography (CBCT). METHODS: Randomly selected sagittal, axial, and coronal CBCT images of the maxillofacial region of 100 patients (50 males, and 50 females) aged between 18-80 were retrospectively screened to determine the extension of the anterior loop. Categorized into (1) younger males, (2) younger females aged (18-44), (3) older males, and (4) older females aged (45-80). Four groups based on dental status were added (1) fully edentulous males, (2) fully edentulous females, (3) dentated males, and (4) dentated females. Measurement tools provided by the software were used to determine the extension of the mental loop. Data was collected for statistical analysis to determine the association between CBCT findings and the patient's gender, age, and dentate status.  RESULTS: In this study, 50 male, and 50 female patients were included for anterior loop measurements. The median age of the sample population was 45 [range 33 to 59]. The mean anterior loop measurements for right and left side were 1.36 mm (0.80 SD) and 1.37 mm (0.79 SD) respectively. Eighty percent of our study participants were dentate and 20% were fully edentulous. Discussion Prior to implant placement proper planning is necessary to avoid misplacement of dental fixtures and injury to the mental nerve. The anterior loop is one of the crucial anatomical structures that clinicians have to consider during the planning. CBCT proved to be the most reliable method of examining the maxillofacial region. No correlation was found between age, gender, and dentate status with changes in the anterior loop measurements. Even though there was no statistical difference among the groups, but there were variations in the anterior loop measurements. In some of the individual cases the anterior loop was 0 mm in one side and 2.5 mm on the other side. This is a big measurement variation of a clinical significance when it comes to implant placement. Looking to the results among groups statistically doesn’t give us the real measurement of the anterior loop. Instead every case should be examined individually to identify the extension of the anterior loop in both sides, even if it was not detected in one of the sides. CONCLUSION: An implant placed in proximity to mental foramen requires planning to avoid complications or nerve injury. Because of possible variations in the anterior loop measurements should be done for each individual case. CBCT is the imaging method of choice to assess the anterior loop.

No description available.

Neste estudo, randomizado, duplo cego, avaliamos a eficácia anestésica em quarenta e dois pacientes, do Setor de Urgência da Faculdade de Odontologia da Universidade de São Paulo, com pulpite irreversível, que receberam mepivacaína 2% (n=21) ou lidocaína 2% (n=21) associadas à epinefrina 1:100.000 para bloqueio do nervo alveolar inferior (BNAI). O sinal subjetivo de anestesia do lábio e língua, a presença de anestesia pulpar e ausência de dor durante o procedimento de pulpectomia foram avaliados, respectivamente, por indagação ao paciente, pelo testador elétrico pulpar (TEP) e pela escala de dor verbal (VAS). Pela técnica pterigomandibular indireta das três posições, foi injetado primeiramente um tubete (1,8mL), e depois de 10 minutos, foi testada a anestesia pulpar (AP), pelo TEP, por duas leituras negativas ao estímulo máximo (80A) do aparelho. Quando não instalada a AP, um segundo tubete (mais 1,8mL) era reinjetado. Confirmada a anestesia pulpar, iniciava-se a pulpectomia. O sucesso do BNAI foi definido como a capacidade de acessar a câmara pulpar e a realização da pulpectomia sem relato de dor (VAS) pelo paciente (escore 0 ou 1), enquanto o insucesso foi caracterizado pelo incomodo/dor (escore 2 ou 3), que impedisse a continuação. Nesse caso, um terceiro e último tubete foi dado por técnicas complementares (intraligamentar ou intrapulpar) para finalizar o procedimento. Na análise estatística utilizou-se o teste Exato de Fisher e ANOVA com nível de significância fixado em 5%. Obtivemos que no grupo Mepivacaína com 1,8mL, a taxa de anestesia pulpar (AP) foi de 52% (11/21), e sucesso no BNAI de 55% (6/11); a injeção de mais 1,8mL (2º tubete) aumentou a AP para 86% (18/21) e o sucesso no BNAI para 55% (10*/18). No Grupo Lidocaína, com 1.8mL, a taxa da AP foi de 33% (7/21), o BNAI foi de 0%; com mais 1,8mL (2º tubete), a AP aumentou para 67% (14/21) e sucesso no BNAI para 14% (2*/14) (*com diferença estatística onde p0,05). A mepivacaína com volume menor proporcionou, clinicamente, maior índice de anestesia pulpar e sucesso do BNAI (pulpectomia total), e permitiu chegar mais próximo da polpa quando comparada a lidocaína. Concluímos que a mepivacaína obteve melhores resultados no sucesso do BNAI para a realização da pulpectomia em molares inferiores com pulpite irreversível. / The aim of this, double blind randomized study, was to evaluate the anesthetic efficacy of inferior alveolar nerve block (IANB) using 2% mepivacaine and 2% lidocaine both associated with adrenaline 1:100,000 in molars with irreversible pulpitis. The sample of these study consisted of forty-two healthy patients diagnosed with irreversible pulpitis actively experiencing pain. For blocking the IAN was established the following protocol: injection of one cartridge (1.8 mL) by the technique pterigomandibular of three indirect positions, expected 10 minutes and electric pulp test (EPT) Vitality Scanner®-SybronEndo, USA was accomplishment. If tooth sensitivity pain persisted another cartridge (plus 1.8 mL) was given by the same technique and the same methodology was performed. The pulpectomy was continued after the confirmation of pulpal anesthesia, which was established as the lack of response at maximum stimulation (80A) of EPT. In cases where the patient reported pain during pulpectomy even confirmed the blockage, a third cartridge was given by complementary techniques (intraligamentary or intrapulpal) to complete the endodontic procedure. The anesthetic efficacy in IANB was established when the pulpectomy was performed without report of pain and without complementation. For analysis and comparison of results we used the Fisher exact statistical test and ANOVA with significance level set at 5%. Regarding the effectiveness of the anesthetic with 1,8 mL mepivacaine, determined pulpar anesthesia (PA) was 52% (11/21), and success in IANB (pulpectomy) 55% (6/11), the most injection of 1,8 mL, increased 86% (18/21) for AP and success in IANB to 55% (10*/18). In the lidocaine group, with 1.8mL, AP rate was 33% (7/21), the IANB was 0%, with a further 1.8 mL (cartridge 2) the AP increased to 67% (14/21) and success was to IANB 14 % (2*/14), (*statistically difference p 0.05). Mepivacaine with smaller volume clinically provided a higher rate of pulpal anesthesia and most successful of IANB (pulpectomy total), allowing to reach nearest dental pulp than lidocaine. Concluded that mepivacaine performed better in success of IANB (pulpectomy) that lidocaine in molars with irreversible pulpitis

O trajeto do canal da mandíbula é oblíquo com sentido póstero-anterior, apresenta-se próximo da cortical óssea alveolar medial, até atingir a face mesial do primeiro molar inferior, a partir desta região aproxima-se da lâmina óssea alveolar lateral até alcançar o forame mentual. Radiograficamente, o canal da mandíbula se apresenta, como uma linha radiolúcida delimitada por duas linhas radiopacas. Existem diversos métodos de exames radiográficos que possibilitem a avaliação do complexo maxilo-mandibular. Estudos mostram que a Tomografia Computadorizada (TC) foi considerado o melhor método para a avaliação do trajeto no sentido vestíbulo-lingual do canal da mandíbula. Foi proposto analisar a morfologia no sentido vestíbulo-lingual das variações do trajeto do canal da mandíbula em imagens de TC utilizando o software Dental Slice®. Com a ferramenta mensuração deste software , avaliou-se 100 TC bilateralmente, criando-se três retas. Uma horizontal (vestíbulo-lingual), dividindo o canal ao meio, e duas retas verticais, tangenciando a face externa lingual e vestibular da cortical do canal. Para análise dos dados utilizou os testes de normalidade, teste de hipótese (teste t e ANOVA) e teste de aderência Anderson Darling. Concluiu-se que existe uma tendência da presença de pouca variabilidade, entre os lados direito e esquerdo; a porção do canal mais próxima ao forame mentual apresenta-se vestibularizado, e na região posterior lingualizado; há necessidade da avaliação topográfica do canal da mandíbula por meio da Tomografia Computadorizada. / The course of the mandibles canal is oblique with posterior-anterior direction, it comes close to the medial cortical alveolar bony, until reaching the mesial face of the first inferior molar, starting from this area, it approaches of the lateral cortical alveolar bony until reaching the forame mentual. Radiographically, the manbible´s canal comes, as a radiolucent line defined by two radiopaque lines. Several methods of exams radiographyc that facilitate the evaluation of the complex maxilo-mandibular. Studies show that the Computerized Tomography (TC) is the best method for consider the evaluation of the course in the vestibule-lingual direction of the mandibles canal. It was intended to analyze the morphology in the vestibule-lingual direction of the variations of the course the mandibles canal in images of TC using the Dental Slice® software. With the mensuration tool of this software, 100 TC was evaluated bilaterally, being created three straight line. A horizontal one (vestibule-lingual), dividing the canal in the middle, and two vertical straight line, being tangent to the lingual external face and vestibular of the canals cortical. For analysis of the data it used the normality tests, hypothesis test (tests t and ANOVA) and test of adherence Anderson Darling. It conclude that a tendency exists the presence of little variability, among the sides right and left. The canal close to the forame mentual presents vestibular direction, and in the posterior area on lingual direction. And Confirm the need of the use of TC in the topographical evaluation of the mandibles canal.