Relación entre la compresión maxilar y potencial impactación del canino superior: Scoping review

El canino maxilar permanente corresponde al segundo diente más frecuentemente impactado en el arco dental. La etiología de esta patología aún no está totalmente definida, sin embargo, investigadores plantean la deficiencia del ancho del hueso maxilar como una posible causa. Objetivo: Investigar la evidencia que asocia menores dimensiones transversales del maxilar a la ocurrencia de la impactación de caninos superiores y esclarecer la posible relación. Materiales y métodos: Se realizó una revisión sistemática exploratoria a partir de una búsqueda amplia de la literatura en bases de datos PubMed, Cochrane, EBSCO y Multibuscador UNAB. Los artículos fueron recopilados, identificados y filtrados según el diagrama de flujo de declaración PRISMA. Resultados: La búsqueda identificó 755 estudios, de los cuales 14 fueron incluidos. Los estudios varían en diseño, edad de estudio y métodos de diagnóstico. La mitad de los estudios reporta una asociación positiva entre compresión maxilar e impactación canina superior, mientras que la otra mitad una asociación negativa. Conclusiones: No hay evidencia suficiente para poder asociar compresión maxilar con impactación de caninos superiores. Estudios con métodos de diagnóstico rigurosos son necesarios para una mejor comprensión. No obstante, se enfatiza la importancia de un diagnóstico precoz, para garantizar mejores resultados y pronóstico más favorable.

The permanent maxillary canine is the second most frequently impacted tooth in the dental arch. The etiology of this disease is not completely defined, yet some researchers propose the deficiency of the width from the maxilla as a possible cause. Objective: To investigate available evidence correlating smaller transverse maxilla dimensions with the occurrence of potential impaction of upper canines and clarify the possible relation. Materials and methods: A systematic exploratory review was carried out based on comprehensive search of the literature in databases such as PubMed, Cochrane, EBSCO and UNAB multi search engine. The articles were compiled, identified and filtered systematically according to the PRISMA flow diagram. Results: Our search identified 755 studies, 14 of which were included. These studies vary in design, patients age, and methods for detection. Half of the studies show a positive correlation between maxillary compression and potential upper canine impaction, whereas the other half show a negative correlation. Conclusions: There is not enough evidence to link maxillary compression to upper canine impaction. Studies with rigorous diagnostic methods for detection are necessary for a better understanding of this relation. Nonetheless, the importance of early diagnosis must be emphasized to guarantee better results and a more favorable prognosis.

Displasia fibrosa maxilar. Del diagnóstico al tratamiento. Reporte de caso / Maxillary fibrous dysplasia. From diagnosis to treatment: Case report / Displasia fibrosa maxilar. Do diagnóstico ao tratamento: Relato de caso

La displasia fibrosa se puede presentar, en cualquier persona, por una mutación en los primeros meses de gestación. Se trata de lesiones óseas benignas en pacientes jóvenes, en las que el tejido óseo normal es sustituido por tejido conectivo fibroso, debido a una alteración funcional de las células, siendo esta la antesala de una neoplasia. El objetivo de éste artículo es presentar un caso local de Displasia Fibrosa Maxilar, enfatizando el manejo clínico, radiográfico, pre y postoperatorio más pertinente. Por lo tanto, se describe el caso de un paciente adolescente de género masculino, afectado por displasia fibrosa en hemimaxilar derecho, a quien le fueron realizados los estudios imagenológicos e histopatológicos necesarios para obtener el diagnóstico definitivo y decidir el abordaje menos invasivo posible cumpliendo con estándares de estética facial; se realizó abordaje intrabucal para shaving óseo, con sedación consciente bajo estricta vigilancia de la especialista en anestesiología y reanimación. Una vez logrado el contorno deseado mediante el uso de piezas de mano de alta y baja velocidad, se realizó la sutura de los tejidos y el paciente egresó ambulante y con buen estado general de salud.

Fibrous dysplasia can occur in any person due to a mutation in the first months of gestation. These are benign bone lesions in young patients, in which the normal bone tissue is replaced by fibrous connective tissue, due to a functional alteration of the cells, being this the prelude to a neoplasm. The aim of this article is to present a local case of Maxillary Fibrous Dysplasia, emphasizing the most relevant clinical, radiographic, pre and postoperative management. Therefore, we describe the case of an adolescent male patient, affected by fibrous dysplasia in the right hemimaxillary, who underwent the necessary imaging and histopathological studies to obtain the definitive diagnosis and decide the least invasive approach possible in compliance with facial aesthetic standards; an intraoral approach was performed for bone shaving, with conscious sedation under strict supervision of the specialist in anesthesiology and resuscitation. Once the desired contour was achieved through the use of high and low speed handpieces, the tissues were sutured and the patient was discharged ambulatory and in good general health.

A displasia fibrosa pode ocorrer em qualquer pessoa devido a uma mutação nos primeiros meses de gestação. São lesões ósseas benignas em pacientes jovens, nas quais o tecido ósseo normal é substituído por tecido conjuntivo fibroso, devido a uma alteração funcional das células, sendo esse o prelúdio de uma neoplasia. O objetivo deste artigo é apresentar um caso local de Displasia Fibrosa Maxilar, enfatizando o manejo clínico, radiográfico, pré e pós-operatório mais pertinente. Portanto, descrevemos o caso de um paciente adolescente do sexo masculino, afetado por displasia fibrosa no hemimaxilar direito, que foi submetido aos exames de imagem e histopatológicos necessários para obter um diagnóstico definitivo e decidir sobre a abordagem menos invasiva possível, em conformidade com os padrões estéticos faciais; foi realizada uma abordagem intraoral para raspagem óssea, com sedação consciente sob estrita supervisão do especialista em anestesiologia e ressuscitação. Depois que o contorno desejado foi obtido com o uso de peças de mão de alta e baixa velocidade, os tecidos foram suturados e o paciente recebeu alta ambulatorial em bom estado geral de saúde.

Atypical Location of Oral Metastasis as the First Manifestation of Renal Carcinoma. Case Report / Localización Atípica de Metastasis Oral como Primera Manifestación de Carcinoma Renal. Reporte de Caso

Oral cavity metastatic tumors derived from primary tumors from other corporal regions are rare, representing barely 1 % of all malignant tumors. Differential diagnosis of these lesions is challenging due to the wide spectrum of lesions with similar clinical presentation and especially when the presence of a primary tumor goes undetected. We present the case of a 55-year-old male with a painless tumor in the anterior maxillary region, vestibular gingiva and palate, with a 2-month evolution. Anatomopathological diagnosis was malignant clear cell tumor, highly suggestive of clear cell renal carcinoma metastasis, and the oral lesion constituted the first sign of illness.

Los tumores metastásicos de cavidad oral derivados de tumores primarios de otras regiones corporales son raros, representando apenas el 1 % de todos los tumores malignos. El diagnóstico diferencial de estas lesiones es desafiante debido al amplio espectro de lesiones con presentación clínica similar y especialmente cuando la presencia de un tumor primario pasa desapercibida. Presentamos el caso de un varón de 55 años con una tumoración indolora en región maxilar anterior, encía vestibular y paladar, de 2 meses de evolución. El diagnóstico anatomopatológico fue de tumor maligno de células claras, altamente sugestivo de metástasis de carcinoma renal de células claras, y la lesión bucal constituyó el primer signo de enfermedad.

Estudio Anatómico y Prevalencia del Canalis sinuosus Evaluado Mediante Cone Beam CT en Pacientes Chilenos / Anatomical Study and Prevalence of Canalis sinuosus Evaluated by Cone Beam CT in Chilean Patients

Canalis sinuosus, canal intraóseo localizado en región maxilar anterior, contiene elementos vasculonerviosos alveolares anterosuperiores. Diversas intervenciones en región maxilar anterior como colocación de implantes, exodoncias, instalación de microtornillos ortodóncicos, procedimientos quirúrgicos, entre otros, pueden comprometer al Canalis sinuosus y/o sus canales accesorios dañando los elementos contenidos en su interior causando complicaciones como hemorragias, parestesia, disestesia, etc. Dado el gran desconocimiento de su existencia, el Canalis sinuosus frecuentemente es confundido con lesiones patológicas y/o endodónticas. Clásicamente la literatura lo describe como una variación anatómica variación anatómica, sin embargo, presenta elevadas prevalencias (51,7 %-100 %), siendo cuestionada esta aseveración. Determinar prevalencia y característica s anatómicas del Canalis sinuosus mediante Cone Beam CT en pacientes chilenos del centro radiológico IMAPROX® entre 2017- 2021. Análisis retrospectivo de 220 CBCT maxilares anonimizados, considerando variables sexo, presencia del Canalis sinuosus, Canalis sinuosus uni/bilateral, diámetro mayor del Canalis sinuosus, presencia/número de accesorios. Análisis estadístico uni y bivariado. 100 % de prevalencia del Canalis sinuosus en ambos sexos, presencia bilateral 100 %. Diámetro mayor promedio del Canalis sinuosus: 2,58 mm. El 76,8 % presentó accesorios, siendo más prevalente la presencia de 2 CA (34,1 %). Una estructura anatómica normal habitual debe presentar sobre 50 % de prevalencia para ser considerada como tal, pero no hay consensos en criterios empleados para definir variación anatómica o estructura anatómica normal habitual. Literatura describe al Canalis sinuosus como variación anatómica, pero estudios actuales muestran elevadas prevalencias: Rusia 67 %, Brasil 88 %, Turquía, Colombia y Chile 100 %. Este estudio encontró 100 % de prevalencia, sugiriendo que Canalis sinuosus es una estructura anatómica normal habitual. Sin embargo, Canalis sinuosus es poco conocido asociándose a numerosas complicaciones por procedimientos odontológicos y/o quirúrgicos en RMA pudiendo generar hemorragias, parestesia/disestesia, dolor agudo, etc. Elevadas prevalencias reportadas sugieren que Canalis sinuosus es una estructura anatómica normal habitual y no una variación anatómica, pero se requieren más estudios y consensos para aseverarlo. Es de relevancia clínica conocer la existencia y localización del Canalis sinuosus para evitar complicaciones.

Canalis sinuosus, an intraosseous canal located in the anterior maxillary region, contains anterosuperior alveolar vascular-nervous elements. Various interventions in anterior maxillary region such as implant placement, extractions, installation of orthodontic microscrews, surgical procedures, among others, can compromise the Canalis sinuosus and/or its accessory canals, damaging the elements contained inside, causing complications such as bleeding, paresthesia, dysesthesia, etc. Given the great ignorance of its existence, Canalis sinuosus is frequently confused with pathological and/or endodontic lesions. Classically, the literature describes it as an anatomical variation, however, it presents high prevalence (51.7 %-100 %), this assertion being questioned. Objective: to determine the prevalence and anatomical characteristics of Canalis sinuosus using Cone Beam CT in Chilean patients from the IMAPROX® radiological center between 2017-2021. Retrospective analysis of 220 anonymous maxillary CBCT, considering variables sex, presence of Canalis sinuosus, uni/bilateral Canalis sinuosus, largest diameter of Canalis sinuosus, presence/number of accessory canals. Univariate and bivariate statistical analysis. The 100 % prevalence of Canalis sinuosus in both sexes, 100 % bilateral presence. Canalis sinuosus average major diameter: 2.58 mm, 76.8 % presented accessory canals, with the presence of 2 accessory canals being more prevalent (34.1 %). A habitual normal anatomical structure must have a prevalence of over 50 % to be considered as such, but there is no consensus on the criteria used to define anatomical variation or normal anatomical structure. Literature describes Canalis sinuosus as anatomical variation, but current studies show high prevalence: Russia 67 %, Brazil 88 %, Turkey, Colombia and Chile 100 %. This study found 100 % prevalence, suggesting that Canalis sinuosus is an normal anatomical structure. However, Canalis sinuosus is little known as it is associated with numerous complications from dental and/or surgical procedures in anterior maxillary region, which can cause bleeding, paresthesia/ dysesthesia, acute pain, etc. High reported prevalences suggest that Canalis sinuosus is an normal anatomical structure and not an anatomical variation, but more studies and consensus are required to confirm this. It is clinically relevant to know the existence and location of Canalis sinuosus to avoid complications.

Mucormycosis of left maxilla: A case report and review

Mucormycosis is an angioinvasive infection caused by fungi of the Zygomycetes order. Rhizopus is the main pathogen responsible for 90% of cases of cerebral mucormycosis. The term rhinocerebral mucormycosis should be used only in the face, palatal, orbital, paranasal sinus, or brain area. Here, we present the case of a 42-year-old man who presented with complaints of pain and swelling in relation to the left upper back tooth region for the past 20 days. In this case, the patient was immunocompromised due to type II diabetes, as well as COVID hospitalization. This case enlightens the investigation, as well as the management protocol followed by post-operative rehabilitation. Early diagnosis and prompt treatment can significantly reduce the morbidity and mortality of these deadly fungal infections.

Proposal for the Modification of the Method to Evaluate the Midpalatal Suture Maturation Status / Proposta de Modificação do Método para Avaliação do Status da Sutura Palatina Mediana

The objective of present research was to propose a new definition for the midpalatal suture (MPS) maturational stages through reevaluation of intermediate stages B, C and D. The sample was composed by 158 cone-beam computed tomography (CBCT) of individuals between 11 and 20 years of age (±15.4 years, 86 females and 71 males), divided into two groups: 74 individuals aged 11-15 years and 84 individuals aged 16-20 years. The CBCT scans were applied to evaluate midpalatal suture maturation status and comprised stages previously classified as B (29), C (92) and D (37). Each axial image was subdivided into six parts in the anteroposterior direction, and each portion was classified according to MPS maturational evaluation methodology. New definitions of stages were proposed. The reliability of the method was tested by two examiners and the intra- and inter-examiner concordances were defined for each evaluation through weighted kappa coefficients and 95% confidence intervals. The chi-square test was used to compare the groups. In all statistical tests, a significance level of 5% was adopted. Two new maturational stages were defined: sub-stage C- and sub-stage C+, with prevalence of 12% and 8.9%, respectively, in 11 to 20-year-olds. The redefinition and validation of the maturational stages of MPS, considering the sub-stages C- and C+, may allow to elucidate the difference in the prognosis of Rapid Maxillary Expansion among individuals aged 11 to 20 years. This data should be confirmed through a clinical study.(AU)

O objetivo da presente pesquisa foi propor uma nova definição para os estágios maturacionais da sutura palatina média (MPS) por meio da reavaliação dos estágios intermediários B, C e D. A amostra foi composta por 158 tomografias computadorizadas de feixe cônico (TCFC) de indivíduos entre 11 e 20 anos de idade (±15,4 anos, 86 do sexo feminino e 71 do sexo masculino), divididos em dois grupos: 74 indivíduos de 11 a 15 anos e 84 indivíduos de 16 a 20 anos. Os exames de TCFC foram aplicados para avaliar o estado de maturação da sutura palatina média e compreenderam os estágios previamente classificados como B (29), C (92) e D (37). Cada imagem axial foi subdividida em seis partes no sentido anteroposterior, e cada porção foi classificada de acordo com a metodologia de avaliação maturacional MPS. Novas definições de estágios foram propostas. A confiabilidade do método foi testada por dois examinadores e as concordâncias intra e interexaminadores foram definidas para cada avaliação por meio de coeficientes kappa ponderados e intervalos de confiança de 95%. O teste do qui-quadrado foi utilizado para comparar os grupos. Em todos os testes estatísticos adotou-se o nível de significância de 5%. Dois novos estágios maturacionais foram definidos: subestágio C- e subestágio C+, com prevalência de 12% e 8,9%, respectivamente, em jovens de 11 a 20 anos. A redefinição e validação dos estágios maturacionais da MPS, considerando os subestágios C- e C+, podem permitir elucidar a diferença no prognóstico da Expansão Rápida da Maxila entre indivíduos de 11 a 20 anos. Esses dados devem ser confirmados por meio de um estudo clínico.(AU)

Osteonecrosis maxilar inferior asociado a bifosfonatos / Lower jaw osteonecrosis associated with bisphosphonates / Osteonecrose do maxilar inferior associada a bisfosfonatos

Introducción: dada la alta prescripción de bifosfonatos, presentamos sus efectos adversos en la esfera odontológica, siendo una complicación poco frecuente, pero de difícil tratamiento. Sin necesidad de suspender el tratamiento, dado el importante beneficio en cuanto a la prevención de fractura por fragilidad. Estas fracturas causan una alta morbimortalidad en contraposición al bajo riesgo que conlleva la Osteonecrosis mandibular asociada a bifosfonatos. Objetivo: orientar al personal de salud que maneja estos fármacos y quien asiste dichas complicaciones a poseer conocimientos para la prevención de osteonecrosis. Identificar y diferenciar los pacientes con mayor riesgo, de acuerdo con la dosis de bifosfonatos y la frecuencia del tratamiento. Materiales y Método: se realizó una revisión bibliográfica en las siguientes fuentes: Scielo, Google académico, Medline/Pubmed, Biblioteca Virtual en Salud (Brasil), desde el año 2005 a la fecha, idiomas español, portugués e inglés. Los descriptores utilizados son bifosfonatos, mandíbula, maxilar, odontología, osteonecrosis, osteonecrosis de los maxilares asociada a bifosfonatos. Resultados: las últimas pautas de tratamiento fueron modificadas en 2014, por consenso de la Asociación Americana de cirugía Oral y Maxilofacial. La patogénesis de la osteonecrosis maxilar asociada a bifosfonatos no está completamente definida, aunque las publicaciones tratan de explicarla. El riesgo de desarrollarla por terapia oral es menor que por su administración vía intravenosa. Discusión: el médico que prescribe el antirresortivo debe conocer el estado de salud dental de su paciente y, en lo posible, remitirlo a examen con el odontólogo antes de iniciar la terapia con bifosfonatos.

Introduction: Given the high prescription of bisphosphonates, we present their adverse effects in the dental sphere, being an infrequent complication, but difficult to treat. There is no need to suspend treatment, given the important benefit in terms of prevention of fragility fractures. These fractures cause high morbimortality as opposed to the low risk associated with bisphosphonate-associated osteonecrosis of the jaw. Objective: To orient the health personnel who handle these drugs and who assist these complications to have knowledge for the prevention of osteonecrosis. To identify and differentiate patients at higher risk, according to the dose of bisphosphonates and frequency of treatment. Materials and Method: A literature review was performed in the following sources: Scielo, Google academic, Medline/Pubmed, Virtual Health Library (Brazil), from 2005 to date, Spanish, Portuguese and English languages. The descriptors used were bisphosphonates, mandible, maxilla, dentistry, osteonecrosis, osteonecrosis of the jaws associated with bisphosphonates. Results: The latest treatment guidelines were modified in 2014, by consensus of the American Association of Oral and Maxillofacial Surgery. The pathogenesis of bisphosphonate-associated maxillary osteonecrosis is not completely defined, although publications try to explain it. The risk of developing it by oral therapy is lower than by intravenous administration. Discussion: The physician who prescribes the antiresorptive drug should know the dental health status of his patient and, if possible, refer him for examination by a dentist before initiating bisphosphonate therapy.

Introdução: dada a alta prescrição de bisfosfonatos, apresentamos seus efeitos adversos na esfera odontológica, uma complicação rara, mas de difícil tratamento. Sem a necessidade de suspender o tratamento, dado o importante benefício em termos de prevenção de fraturas por fragilidade. Essas fraturas causam alta morbidade e mortalidade, em contraste com o baixo risco associado à osteonecrose da mandíbula associada aos bisfosfonatos. Objetivo: orientar a equipe de saúde que manipula esses medicamentos e que atende a essas complicações para que tenham conhecimento sobre a prevenção da osteonecrose. Identificar e diferenciar os pacientes de maior risco, de acordo com a dose de bisfosfonatos e a frequência do tratamento. Materiais e Método: foi realizada uma revisão da literatura nas seguintes fontes: Scielo, Google acadêmico, Medline/Pubmed, Biblioteca Virtual em Saúde (Brasil), de 2005 até a presente data, idiomas espanhol, português e inglês. Os descritores utilizados foram: bisfosfonatos, mandíbula, maxila, odontologia, osteonecrose, osteonecrose dos maxilares associada a bisfosfonatos. Resultados: as diretrizes de tratamento mais recentes foram modificadas em 2014, por consenso da Associação Americana de Cirurgia Oral e Maxilofacial. A patogênese da osteonecrose da mandíbula associada a bisfosfonatos não está totalmente definida, embora a literatura tente explicá-la. O risco de desenvolvê-la com a terapia oral é menor do que com a administração intravenosa. Discussão: o médico que prescreve o medicamento deve estar ciente do estado de saúde bucal do paciente e, se possível, encaminhar o paciente para ser examinado por um dentista antes de iniciar a terapia com bisfosfonatos.

Molecular mechanisms of tooth, maxilla and mandible development / 口腔医学

@#Understanding the pattern and molecular mechanisms of tooth, maxilla and mandible development is the prerequisite for studying their regeneration. Tooth development can be divided into three stages: bud-bell stage, tooth crown development stage and tooth root development stage. During these processes, key genes show spatial and temporal expression pattern. Tooth development is a complex process involving interactions between dental epithelium and mesenchyme, precise regulations of enamel knots in cusp patterning, as well as successful eruption into the oral cavity under proper biomechanical stress and signaling transductions. The development of tooth, maxilla and mandible, all of which originate from the first branchial arch, is independent and regulates each other to form a whole during development. Any developmental defects of them will ultimately cause defects to the others. In this paper, we briefly reviewed the development of tooth, maxilla and mandible, proposed that the homeostasis of microenvironment is critical for their development. Moreover, we reviewed the role of Meckel’s cartilage, a special structure and signaling mechanism during mandible development. At last, we proposed an integrated development model of tooth, maxilla and mandible. We also hope that the regeneration of fully functional tooth, maxilla and mandible in human can be achieved based on fundamental knowledge we have gained so far.

3D finite element analysis of the influence of upper lip pressure on the maxilla for patients with unilateral alveolar cleft / 口腔疾病防治

Objective @#To investigate the biomechanical effects of upper lip pressure on the maxilla in patients with a unilateral alveolar cleft and provide evidence for clinical diagnosis and treatment. @*Methods @#A 3D finite element maxillary model was generated based on cone beam CT (CBCT) data from an 11-year-old female patient with a unilateral alveolar cleft. Two different kinds of upper lip pressure, postsurgery pressure and normal pressure, were applied to the model. The displacement and stress of each reference node were compared and analyzed. @*Results @# By loading upper lip pressure, the maxillary alveolar crest rotated toward the defect and was displaced downward and backward. The displacement of the noncleft side was greater than that of the cleft side and it decreased gradually from the anterior to the posterior. The stress was concentrated on the anterior portion of the alveolar crest. The stress on the noncleft side was greater than that on the cleft side and it decreased gradually from the anterior to the posterior. The maximum stress was concentrated on the palate around the defect. The displacement and stress in the postsurgery group were greater than those of the normal group (P<0.05). @*Conclusion @#By loading upper lip pressure, the maxilla demonstrated asymmetry three-dimensionally. The adverse effects on the maxilla could be mitigated by reducing the upper lip pressure.

Influence of implant macro-designs on primary and secondary implant stability

Introduction: Tapered implants have shown that thanks to their macro design they are capable of expanding the surgical bed performed by the surgeon, which in clinical practice gives a feeling of greater stability, however it is highly subjective and dependent on the operator. Aim: To analyze the influence of the implant macro design in the primary and secondary stability by means of analysis of resonance frequency and force of insertion. Methods: 38 Screw Type and Tapered Type implants were placed in 18 patients in the Bucomaxillofacial Implantology program of the University of Chile during 2006 and 2007 in type II or III bone jaws according to Leckholm and Zarb. Implant stability, implant stability coefficient (ISQ), was measured through Ostell® mentor at the time of installation (ISQ1) and then at connection (ISQ2) and the Insertion Torque through the Osseoset® machine: 17 Screw Type implants with an approximate average contact area of 237 mm2 (3.75/15 mm; 3.75/13 mm) and 17 Tapered Type implants with an approximate average contact area of 226 mm2 (4.3/13 mm; 4.3/16 mm). Results: The averages of ISQ1 and ISQ2 and Insertion Torque respectively for implants with an approximate contact area of 237 mm2 were 71.3 ISQ1, 66.6 ISQ2 and 44.52 Ncm; for 226 mm2 implants it was 75 ISQ1, 72.5 ISQ2 and 48.82 Ncm. Conclusion: Implants with an average contact area of approximately 226 mm2 (Tapered Type) present significantly higher primary and secondary stability than those with an average contact area of approximately 237 mm2 (Screw Type). (Average ISQ1: p = 0.0473; Insertion Torque: p = 0.0031 and Average ISQ2: p = 0.0039).

Introducción: Los implantes Cónicos han demostrado que gracias a su macro diseño son capaces de expandir el lecho quirúrgico realizado por el cirujano, lo que en la práctica clínica da una sensación de mayor estabilidad, sin embargo, ella es altamente subjetiva y dependiente del operador. Objetivo: Analizar la influencia del diseño del implante en la estabilidad primaria y secundaria mediante análisis de frecuencia de resonancia y Torque de Inserción. Métodos: 38 implantes Tipo Tornillo y Tipo Cónico fueron colocados en 18 pacientes en el programa de Implantología Bucomáxilofacial de la Universidad de Chile durante el año 2006 y 2007 en maxilares de hueso tipo II o III según Leckholm y Zarb. Se midió la estabilidad implantaria, coeficiente de estabilidad del implante (ISQ), a través de Ostell® mentor al momento de la instalación (ISQ1) y luego en la conexión (ISQ2) y el Torque de Inserción a través de el motor Osseoset®: 17 implantes Tipo Tornillo de área de contacto promedio aproximada de 237 mm2 (3.75/15 mm; 3.75/13 mm) y 17 implantes Tipo Cónico de área de contacto promedio aproximada de 226 mm2 (4.3/13 mm; 4.3/16 mm). Resultados: Los promedios de ISQ1 e ISQ2 y Torque de Inserción respectivamente para implantes de área contacto aproximada de 237 mm2 fue de 71,3 ISQ1, 66,6 ISQ2 y 44,52 Ncm; para implantes de 226 mm2 fue de 75 ISQ1, 72,5 ISQ2 y 48,82 Ncm. Conclusión: Los implantes de área contacto promedio aproximada de 226 mm2 (Tipo Cónicos) presentan estabilidad primaria y secundaria significativamente mayor a los de área contacto promedio aproximada de 237 mm2 (Tipo Tornillo). (Promedio ISQ1: p = 0.0473; Torque de Inserción: p = 0.0031 y Promedio ISQ2: p = 0.0039).

Mechanical behavior of implant-supported full-arch prostheses in different locations in the maxilla: 3D-FEA and strain gauge analysis / Comportamento mecânico de próteses de arco inteiro implanto-suportadas em localizações diferentes na maxila: análise 3D-FEA e strain gauge

The maxillary bone restriction can limit the implants position to support a full-arch prosthesis. Objective:Therefore, this study evaluated the biomechanical behavior of a full-arch prosthesis supported by six implants in different configurations: group A (implants inserted in the region of canines, first premolars and second molars), group B (implants inserted in the region of first premolar, first molar and second molar) and group C (implants in second premolar, first premolar and second molar). Material and Methods: The models were analyzed by the finite element method validated by strain gauge. Three types of loads were applied: in the central incisors, first premolars and second molars, obtaining results of von-Mises stress peaks and microstrain. All registered results reported higher stress concentration in the prosthesis of all groups, with group C presenting higher values in all structures when compared to A and B groups. The highest mean microstrain was also observed in group C (288.8 ± 225.2 µÎµ/µÎµ), however, there was no statistically significant difference between the evaluated groups. In both groups, regardless of the magnitude and direction of the load, the maximum von-Mises stresses recorded for implants and prosthesis displacements were lower in group A. Conclusion: It was concluded that an equidistant distribution of implants favors biomechanical behavior of full-arch prostheses supported by implants; and the placement of posterior implants seems to be a viable alternative to rehabilitate totally edentulous individuals. (AU)

A limitação óssea maxilar totais pode limitar o posicionamento dos implantes para suportar uma prótese de arco total. Objetivo: Sendo assim, este estudo avaliou o comportamento biomecânico de uma prótese de arco total suportada por seis implantes em diferentes configurações: grupo A (implantes inseridos na região de caninos, primeiros pré-molares e segundos molares), grupo B (implantes inseridos na região de primeiro pré-molar, primeiro molar e segundo molar) e grupo C (implantes em segundo pré-molar, primeiro pré-molar e segundo molar). Materiais e métodos: Os modelos foram analisados pelo método de elementos finitos validados por extensometria. Foram aplicados três tipos de cargas: nos incisivos centrais, primeiros pré-molares e nos segundos molares, obtendo resultados de picos de tensão de von-Mises e microdeformação. Todos os resultados registrados mostraram maior concentração de tensão na prótese de todos os grupos, sendo que o grupo C apresentou maiores valores em todas as estruturas quando comparado com os grupos A e B. A maior média de microdeformação também foi observada no grupo C (288,8 ± 225,2 µÎµ/µÎµ), no entanto, não houve diferença estatisticamente significativa entre os grupos avaliados. Em todos os grupos, independentemente da magnitude e direção da carga, as tensões máximas de von-Mises registradas para os implantes e deslocamentos de próteses foram menores no grupo A. Conclusão: Concluiu-se que a distribuição de implantes de forma equidistante favorece o desempenho biomecânico das próteses de arco total suportada por implantes; e o posicionamento de implantes posteriores parece ser uma alternativa viável para reabilitar indivíduos densdentados totais. (AU)

Prevalence and extent of Alveolar dehiscence and fenestration in Class I hyperdivergent subjects with different buccolingual inclinations of maxillary molar teeth: a CBCT study

Buccolingual position of teeth could affect the prevalence of alveolar bone defects. Presence of alveolar defects may have a deleterious effect on orthodontic treatment. The aim was to assess the prevalence and extent of dehiscence and fenestration in Class I hyperdivergent subjects and correlate it with buccolingual inclinations(BL) of maxillary first molar teeth. Methods: This retrospective study involved 80 CBCTs of class I hyperdivergent subjects divided into two groups - group A (n=33) buccolingual inclination >9º and group B (n=47) buccolingual inclination <9º. Prevalence and extent of alveolar bone dehiscence and fenestrations were measured in CBCTs using OSIRIX Lite software. Descriptive statistics, Mann Whitney U test and Spearman correlation were done for evaluating intergroup differences and correlation with Buccolingual inclination. Results: Overall prevalence of dehiscence and fenestration in maxillary first molars was 60.95% and 5% respectively. In the buccal alveolar bone, prevalence of dehiscence was highest in group A (84.6%) for 16 and in the lingual alveolar bone prevalence of dehiscence was highest in group B (71.4%) for 26 . On intergroup comparison, the extent of lingual alveolar bone dehiscence (26) in group B was significantly higher (p value <0.05) than in group A. No significant correlation between the extent of dehiscence and fenestration with buccolingual inclination of molar teeth was noted. Conclusion: Molar teeth with BL inclinations of more than 9º had higher prevalence of dehiscence on the buccal side and molar teeth with BL inclinations less than 9 degrees had more dehiscence on the lingual side. But no significant correlation of BL inclination with prevalence and extent of dehiscence and fenestration was noted

Rosai-Dorfman disease of the oral cavity

ABSTRACT First described by J Rosai and R F Dorfman in 1969, Rosai-Dorfman disease (RDD) is a benign, self-limiting histiocytosis of unknown etiology. It is usually seen in the first two decades of life. The most frequent clinical presentation is painless, bilateral cervical lymphadenopathy accompanied by fever, weight loss, and an elevated ESR. However, RDD without nodal involvement is extremely rare, and the most common extranodal location is the head and neck region, mainly affecting the nasal cavity, pharynx, and paranasal sinuses. Oral location of RDD is occasional; according to our knowledge, only 17 cases of oral Rosai-Dorfman disease without lymph node involvement have been found in the literature. Because of the rarity of these isolated oral presentations, the clinical and radiological aspects need to be more studied. This article aims to present a rare case of oral Rosai-Dorfman disease without nodal involvement, detail the clinical and radiological signs, and the treatment strategy used in our patient.

Survival Outcomes and Patterns of Failure in Maxillary Alveolus Squamous Cell Carcinoma

Abstract Introduction Squamous cell carcinoma (SCC) of the maxillary alveolus is a relatively rare disease. There is lack of data on this subsite as compared with other sites. The factors that affect survival in cases of maxillary alveolar SCC are tumor stage, local and cervical metastases, histological grading, and the margin status. Objectives To evaluate the overall survival (OS), the disease free survival (DFS), and the complex interaction and effects of margin status, histological differentiation, habits (such as smoking and the use of smokeless tobacco products), and cervical and distant metastases based on clinicopathological data. Methods We examined the electronic database at our hospital from 2003 to 2017. We included all cases with a histopathological diagnosis of SCC of the maxillary alveolus. Tumors originating primarily from the maxillary alveolus were included, while those originating from adjacent subsites, like the hard palate, the buccal mucosa or the maxillary sinus were excluded. We also excluded all the patients who were not operated on with a curative intent. Results More than half of the patients had stage-IV tumors at the time of presentation, while only one fourth of them had nodal metastasis. The rate of recurrence increased in cases of primary tumors in advanced stages and the degree of histological differentiation. The 2-year and 5-year OS rates were of 54.5% (18 patients) and 30.3% (10 patients) respectively. Conclusion Primary tumors in advanced stages, histological grade, and presence of nodal metastasis are poor prognostic markers in terms of long-term survival.

Efficacy of Buccal Infiltration with or without Palatal Injection for Posterior Maxillary Teeth Extraction - A Split-Mouth Randomized Trial

ABSTRACT Objective: To evaluate the feasibility of posterior maxillary teeth extraction buccal infiltration with or without the use of palatal injection. Material and Methods: A total of 70 patients underwent extraction of bilateral maxillary posterior teeth under 2% lignocaine hydrochloride with 1:2,00000 adrenaline infiltration in this single-centric split-mouth randomized trial. The test side was administered with a buccal infiltration of 2 mL of anesthetic alone. An extended waiting period of 10 minutes was given before the commencement of the procedure. A standard protocol was followed for the control side. A single operator performed all extractions. Results: A total of 140 posterior maxillary teeth were extracted. Patients marked pain perception on a visual analogue scale in three different instances. During the administration of injections for the test side, the pain score was less than that of the control side and was statistically significant. The overall pain during the extraction procedure was comparable and statistically insignificant. The overall success of the method was 90%. Conclusion: Extraction of posterior maxillary teeth was feasible with a single buccal infiltration without palatal injection in most cases using an extended waiting period. Dentists can attempt extraction without palatal injections with optimal success. However, the alternate technique could be used when there is a necessity for rescue palatal anesthesia.

Synchronous jawbone diseases: a multicenter retrospective study

Abstract The aim of this study is to report an original case series of synchronous jawbone diseases. Data of patients seen over 13 years were extracted from the files of three Oral Radiology and Pathology diagnostic centers in Brazil. The clinical, radiographic, and laboratory characteristics were tabulated and analyzed by the authors; the patients were described according to lesion type. Seventy-two synchronous jawbone diseases were included in this study. Florid osseous dysplasia, Gorlin-Goltz syndrome, and cherubism were the most frequent disorders reported in this case series. In addition, the posterior mandible area was the main site of manifestation. Florid osseous dysplasia and Gorlin-Goltz syndrome represented two-thirds of our samples. With the utilization of adequate demographic, clinical, and radiologic information, it is possible to diagnose most of the synchronous lesions of jawbones. Sometimes, however, we need complementary exams, such as histopathologic and biochemical analysis or dosing of calcium, phosphorus, and alkaline phosphatase.

Actinomycotic osteomyelitis in the maxilla and the zygomatic bone: a case report and literature review / 口腔疾病防治

Objective@# To investigate the clinical features, diagnosis and treatment of osteomyelitis of the jaw caused by an actinomycotic infection and to provide a reference for clinical diagnosis and treatment.@*Methods@#A case of osteomyelitis in the bilateral maxilla and the left zygomatic bone and arch caused by a mixed bacterial infection dominated by Actinomycetes was reviewed and analyzed in combination with the literature. @*Results @#The patient had left upper posterior tooth pain with repeated left facial swelling for 7 months. The patient's left face was swollen before surgery, the left maxillary alveolar bone was necrotic, and the upper palate showed fistula discharge. A maxillofacial magnetic resonance imaging scan excluded tumors and other space-occupying lesions. According to CBCT images, the initial diagnoses were left infraorbital space infection and osteomyelitis of the bilateral maxillary, the left zygomatic bone, the left zygomatic arch and the lateral orbital wall. Necrosis of the left maxilla and the zygomatic bone was excised, the focus was cleared and the focal tooth was extracted under general anesthesia. Histopathological results confirmed osteomyelitis and actinomycotic infection. Anti-inflammatory therapy with penicillin sodium was given before surgery, and piperacillin sodium and tazobactam sodium, dexamethasone sodium phosphate, tranexamic acid and mecobalamine were given after surgery. The patients' 6-month follow-up results showed that the maxillofacial shape was basically symmetrical; no ulceration, pus or abnormal secretion was found in the skin or intraoral mucosa; and the surgical area showed good recovery. A review of the relevant literature showed that Actinomyces is an opportunistic pathogen, and factors such as trauma and dental infection have been implicated in the pathogenesis of osteomyelitis. In addition to surgery, antibiotics are used to treat the disease and multidisciplinary symptomatic treatment combined with supportive treatment is required to achieve a better prognostic effect. @*Conclusion @# Actinomycotic osteomyelitis occurring in the maxilla and the zygomatic bone is an extremely rare disease that can be diagnosed by clinical manifestations, bacteriological examination and biopsy. Appropriate and effective penicillin drugs should be given at the initial stage of treatment, more sensitive antibiotics should be selected according to the results of the drug sensitivity test, and the lesions should be surgically removed when the patient's condition improves. Active symptomatic and supportive treatment should be performed during the treatment period.

Clinical effect of a door shaped individualized dental archwire on the treatment of maxillary transposed canines / 口腔疾病防治

Objective @#To discuss the effectiveness and mechanism for movement of maxillary buccally transposed canines by using a door-shaped individualized dental archwire mechanic and to provide a reference for clinicians.@*Methods@#Eight patients with unilateral maxillary transposed canines were enrolled. All patients were treated with door-shaped individualized archwires. Before treatment (T1) and after the crowns of the transposed canines were moved to the right buccal positions in the dental arch during the treatment (T2), orthopantomograms were taken both at T1 and T2 to compare the linear changes (distance changes of the crown and root apex) and angular changes to study the mechanisms of tooth movement. The probing depth and buccal crown height were measured using a periodontal probe to compare periodontal changes before treatment (T1) and after treatment (T3) between the transposed canines and contralateral canines. @*Results@# All eight transposed canines were successfully brought back to their normal dental arch position but were made more buccal by using the door-shaped individualized dental archwire, with a mean of (11.5 ± 2.7) months. The average overall duration was (28.3 ± 4.7) months. The crown distance changes of the canines from T1 to T2 (8.1 mm) were greater than those of the root apexes (1.5 mm) (P<0.05). The mean angulation changes of the long axes of the canines were 17.5°. There was no significant difference in the depth of periodontal measurement and buccal crown height measurement between T1 and T3 (P>0.05). @*Conclusion @# The buccal movement of maxillary transposed canines under a door-shaped individualized dental archwire was effective and feasible. The movement pattern under this mechanism was controlled tipping.

Directrices para el diagnóstico y tratamiento de Molares Retenidos / Guidelines for diagnosis and treatment of impacted molars

Los terceros molares son piezas dentarias correspondientes a la dentición permanente y se encuentran por detrás de los segundos molares. Erupcionan entre los 18 y 27 años aproximadamente, tienen variedad de formas, anomalías y disposición diversa. Normalmente se encuentran total o parcialmente retenidos en el hueso maxilar. La retención es muy frecuente y afecta aproximadamente al 75% de la población. La causa principal es por la falta de espacio dentro de la boca. La patología derivada de la retención de un tercer molar puede generar diferentes alteraciones: abscesos, sinusitis, reabsorción de las raíces de los dientes adyacentes, caries del molar retenido y/o del segundo molar, úlceras en la mucosa contigua, podrían generar quistes, ameloblastomas y ulceraciones leucoqueratósicas que pueden degenerar en carcinomas, alteraciones nerviosas o vasomotoras: dolores faciales, trismus, y parálisis facial ipsilateral. Las extracciones profilácticas de terceros molares asintomáticos están justificadas cuando los terceros molares se encuentran bajo prótesis removible que puede estimular su erupción, molares semierupcionados que pueden generar pericoronitis, caries o problemas periodontales; pacientes que van a ser sometidos a radioterapia; cuando el diente incluido interfiera en una cirugía ortognática. Si el molar retenido presenta sintomatología por parte del paciente está aconsejada su extracción quirúrgica.

The third molars are dental pieces corresponding to the permanent dentition and are located behind the second molars. They erupt between the ages of 18 and 27 approximately, have a variety of shapes, anomalies, and diverse dispositions. They are normally fully or partially retained in the maxillary bone. Retention is very frequent and affects approximately 75% of the population. The main cause is due to the lack of space inside the mouth. The pathology derived from the retention of a third molar can generate different alterations: abscesses, sinusitis, resorption of the roots of adjacent teeth, caries of the retained molar and/or second molar, ulcers in the contiguous mucosa, could generate cysts, ameloblastomas and leukokeratotic ulcerations that can degenerate into carcinomas, nervous or vasomotor disorders: facial pain, trismus, and ipsilateral facial paralysis. Prophylactic extractions of asymptomatic third molars are justified when the third molars are under removable prosthesis that can stimulate their eruption, semi-erupted molars that can generate pericoronitis, caries or periodontal problems; patients who are going to undergo radiotherapy; when the included tooth interferes with orthognathic surgery. If the retained molar presents symptoms on the part of the patient, its surgical extraction is recommended.

The challenges of reconstruction and rehabilitation of atrophic jaw with an autogenous graft from skull cap ­ a case report / Os desafios da reconstrução e reabilitação de mandíbula atrófica com enxerto autógeno de calota craniana ­ relato de caso

Introduction: One of the challenges of maxillofacial surgery is the rehabilitation of patients with severe bone loss, using implant-supported prostheses. This challenge is based on the small remaining bone structure, and on the need to reconstruct the structure for the rehabilitation with autogenous or exogenous grafts. Case report: We report the case of a patient with severe maxillary atrophy, where a skullcap graft was performed associated with implant placement and prosthetic completion 14 months after the start of treatment. Final considerations: We demonstrate clinical safety for the use of extraoral grafts without complications, representing a good alternative treatment for this group of patients.

Introdução: um dos desafios da cirurgia bucomaxilofacial é a reabilitação de pacientes com perda óssea severa, utilizando próteses implantossuportadas. Este desafio baseia-se na pequena estrutura óssea remanescente e na necessidade de reconstrução da estrutura para a reabilitação com enxertos autógenos ou exógenos. Relato de caso: Relatamos o caso de um paciente com atrofia maxilar grave, onde foi realizado enxerto de calota craniana associado à instalação de implante, com finalização protética 14 meses após o início do tratamento. Consideracoes finais: Demonstramos segurança clínica para o uso de enxertos extrabucais sem complicações, representando uma boa alternativa de tratamento para este grupo de pacientes.