Correlation of the pharyngeal space with the morphology of the mandible and hyoid bone in patients with different facial types and skeletal classes

Orientador: Francisco Haiter NetoTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: O sistema estomatognático é constituído por tecidos e órgãos que desempenham funções importantes como respiração, mastigação, deglutição e fonação. Uma função respiratória deficiente pode influenciar negativamente o desenvolvimento craniofacial, gerando alterações na morfologia e no mecanismo de ação do espaço faríngeo, da mandíbula e do osso hioide. A correlação entre estas estruturas não está claramente elucidada na literatura, necessitando-se assim de mais informações acerca do assunto. Desse modo, o objetivo neste trabalho foi avaliar o volume do espaço faríngeo e sua correlação com a morfologia da mandíbula e o osso hioide em pacientes com diferentes tipos faciais e classes esqueléticas. Além disso, outro objetivo foi desenvolver uma fórmula para estimar o volume do espaço faríngeo a partir de medidas lineares. Assim, foram selecionadas, 161 imagens de tomografia computadorizada de feixe cônico adquiridas no aparelho i-CAT Next Generation®. Dessas imagens, 80 eram de indivíduos do sexo masculino e 81 de indivíduos do sexo feminino, com idades entre 21 e 58 anos. A classe esquelética e o tipo facial foram determinados para cada paciente, a partir de reconstruções multiplanares, utilizando-se o software NemoCeph®. Dezessete medidas lineares e angulares foram realizadas com o software Carestream 3D Imaging® 3.4.3, enquanto a análise volumétrica do espaço faríngeo foi realizada por meio da ferramenta de segmentação semiautomática do software Insight ITK -SNAP® 2.4.0. O software MedCalc Statistical® 15.8 foi utilizado para as análises estatísticas Coeficiente de correlação intraclasse, ANOVA, Tukey, correlação de Pearson e regressão linear. Foram observadas diferenças estatisticamente significantes entre as diferentes classes esqueléticas nas mensurações Ângulo transverso da mandíbula, Distância ântero-posterior da mandíbula, Distância látero-lateral da mandíbula, Distância ântero-posterior da vértebra C2, Distância látero-lateral da epiglote, Menor distância do espaço faríngeo e Volume do espaço faríngeo. Em relação aos diferentes tipos faciais, as mensurações Distância látero-lateral do osso hioide, Ângulo transverso da mandíbula, Ângulo ântero-posterior da mandíbula, Distância ântero-posterior da vértebra C2, Distância ântero-posterior da epiglote e Menor distância do espaço faríngeo mostraram diferenças estatisticamente significantes. Houve correlação significativa entre o volume do espaço faríngeo e as medidas realizadas, com exceção às mensurações de Ângulo transverso do osso hioide, Distância látero-lateral do osso hioide, Ângulo transverso da mandíbula, Ângulo ântero-posterior da mandíbula e Distância espinha nasal anterior - espinha nasal posterior. O modelo de regressão linear realizado para predizer o volume do espaço faríngeo obteve um R2 de 0.8362. Concluiu-se que houve correlações significativas entre o volume do espaço faríngeo e as mensurações na mandíbula e no osso hioide, recomendando-se que o sistema estomatognático seja avaliado de uma maneira integral e isolada. Além disso, foi possível desenvolver um modelo de regressão linear com precisão, o que resultou em uma fórmula útil para a predição do volume do espaço faríngeoAbstract: The stomatognathic system consists on tissues and organs that perform important functions such as breathing, chewing, swallowing and phonation. Deficient respiratory function may affect the craniofacial development, leading to changes in the morphology and mechanism of action of the pharyngeal space, mandible and hyoid bone. The correlation between these structures is not clearly elucidated in the literature, requiring further information about this subject. The aim of this study was to evaluate the volume of the pharyngeal space and its correlation with mandible and hyoid bone in patients with different facial types and skeletal classes. In addition, another objective was to develop a formula to determine the volume of the pharyngeal space using only linear measurements. Thus, 161 cone-beam computed tomography images, acquired on the i-CAT Next Generation® device. Out of these images, 80 belonged to males and 81 belonged to females, aged between 21 and 58 years. The skeletal class and facial type were determined for each patient from multiplanar reconstructions using NemoCeph® software. Seventeen linear and angular measurements were performed with the Carestream 3D Imaging® Software 3.4.3, while a volumetric analysis of the pharyngeal space was performed using the semiautomatic segmentation tool of the Insight ITK-SNAP® 2.4.0 software. MedCalc Statistical® software in version 15.8 was used for Intraclass correlation coefficient, ANOVA, Tukey, Pearson's correlation and linear regression analyzes. Statistically significant differences were observed between the different skeletal classes in the Transverse Angle of Mandible, Anterior-Posterior angle of Mandible, Latero-Lateral distance of Mandible, Anterior-Posterior distance of airway space in the region of C2 vertebra, Latero-Lateral distance of airway space in the region of Epiglottis, Shortest Distance of the pharyngeal space and Pharyngeal Space Volume. In relation to the different facial types, Latero-Lateral distance of Hyoid Bone, Transverse Angle of Mandible, Anterior-Posterior distance of Mandible, Anterior-Posterior distance of the airway space in the region of C2, Anterior-Posterior distance of the airway space in the region of Epiglottis and Shortest Distance of the pharyngeal space showed statistically significant differences. There was a statistically significant correlation between the Pharyngeal Space Volume and all the measurements, with exception of the Transverse Angle of Hyoid Bone, Latero-Lateral distance of Hyoid Bone, Anterior-Posterior distance of Mandible, Transverse Angle of Mandible and Anterior Nasal Spine¿Posterior Nasal Spine Distance. The linear regression model used to predict the pharyngeal space volume obtained an R2 of 0.8362. It was concluded that there were significant correlations between the pharyngeal space volume and the mandible and hyoid bone measurements, suggesting that the stomatognathic system should be evaluated in an integral and isolated way. Furthermore, it was possible to develop a linear regression model with precision, resulting in a useful formula for predicting the volume of the pharyngeal spaceDoutoradoRadiologia OdontologicaDoutor em Radiologia OdontológicaCAPE

Radiographic evaluation of morphological alterations of mandible resulting from tooth loss

Orientador: Paulo Henrique Ferreira CariaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaRESUMO O tecido ósseo sofre modificações estruturais de acordo com as tensões que agem sobre ele. Na mandíbula, único osso móvel do crânio, os músculos provocam tensões durante sua movimentação na mastigação e fonação. O envelhecimento e a perda dentária podem provocar alterações morfológicas na mandíbula, com consequências clínicas. O objetivo deste trabalho foi correlacionar a espessura da cortical mandibular na região de forame mentual (FM) e ângulo goníaco (AG) e, a altura do processo coronóide (PC) com antímeros direito e esquerdo, idade, gênero, tipos faciais e cefálicos, número e local das perdas dentárias em uma amostra populacional. Para isso, foram avaliadas 240 radiografias panorâmicas de voluntários de ambos os gêneros, com idades entre 21 e 80 anos. Após as medidas faciais e cefálicas, as radiografias panorâmicas foram fotografadas e transferidas para o programa Radiocef Studio 2® no módulo Radio Imp.As mensurações foram realizadas por um único avaliador em três momentos distintos nas seguintes regiões: base mandibular até a borda superior da imagem da cortical mandibular na região do forame mentual, altura dos processos coronóides e espessura da cortical na região do ponto goníaco, todos bilateralmente. As medidas foram submetidas à análise estatística Anova Two Way Analasys pelo software SigmaStat®, com nível de significância de 5%. Observou-se diferença estatística significante em relação ao gênero, idade, tipo cefálico, número e local das perdas dentárias quando correlacionadas às mensurações avaliadas. Não houve diferença estatística quando correlacionados os diferentes tipos faciais e os lados direito e esquerdo de pacientes do mesmo gênero. Conclui-se que perdas dentárias provocam alterações na morfologia óssea mandibular. Além disso, fatores como idade, gênero e tipo cefálico também devem ser levados em consideração na análise da morfologia óssea mandibularABSTRACT The bone tissue undergoes structural changes according to the mechanical forces acting on it. In the mandibular bone, the lower teeth and muscles produce significant tension in the process of chewing and speech. Since the mandibular bone presents the dental arch and insertion of masticatory muscles, the aim of this study was to correlate the mandibular cortical thickness in the region of the mental foramen (MF) and gonial angle (GA) and the height of the coronoid process (CP) with right and left sides, age, gender, cephalic and facial types and number and location of tooth loss. The study population comprised 240 patients of both genders, age ranged from 21-80 years.After the facial and cephalic measures, all panoramic radiographs were photographed and imported to the program Radiocef Studio 2®in Radio Imp module, and the measurements were carried out by a single examiner in three distinct moments in the following regions: the mandibular basis up to the top edge of the mandibular cortical in the region of the mental foramen on both sides, height of both coronoid process and cortical thickness in the region of gonial point bilaterally. All measures were statistically analyzed by two?way ANOVA using the SigmaStat®software, with significance level of 5%.It was observed statistically significant differences in relation to gender, age, cephalic type, number and location of tooth loss as they were correlated to measurements assessed. There was no statistical difference by correlating different facial types and the right and left sides of the same gender patients. It was concluded that tooth loss causes changes in mandibular bone morphology. Furthermore, factors such as age, gender and cephalic type must also be taken into account in the analysis of mandibular bone morphologyMestradoRadiologia OdontologicaMestre em Radiologia Odontológic

Meloxicam as a Radiation-Protective Agent on Mandibles of Irradiated Rats

<div><p>Abstract This study evaluated the action of ionizing radiation and the possible radioprotective effect of the non-steroidal anti-inflammatory drug meloxicam on the bone physiology of rat mandibles by assessing the alveolar socket healing and bone strength. Forty male Wistar rats were divided in 4 groups (n=10): control (CG), irradiated (IG), meloxicam (MG), meloxicam irradiated (MIG). A dose of 0.2 mg/kg meloxicam was administered to MG and MIG. After this, IG and MIG were irradiated with 15 Gy radiation dose in the mandible. Forty days after the above procedures, the mandibular first molars were extracted and the animals were killed after 15 or 30 days (n=5). Micro-computed tomography and bending test were used to evaluate alveolar socket healing and bone strength, respectively. At 15 days, bone volume, bone volume fraction and trabecular thickness were higher in the CG and MG than in the IG and MIG; and trabecular separation was higher in the IG compared with the others. At 30 days, there was a difference only in trabecular separation, which was higher in IG than in CG and MG, and MIG did not differ from the others. Bone strength was lower in IG compared with CG and MG, and MIG did not differ from the others. In conclusion, the ionizing radiation affected the bone physiology of rat mandibles, delaying the alveolar socket healing and reducing the bone strength. Moreover, the meloxicam had a positive effect on the trabecular separation in alveolar socket healing and on the bone strength.</p></div

The fundaments of CBCT and its use for evaluation of paranasal sinuses: review of literature

ethods such as Magnetic Resonance Imaging (MRI), Computed Tomography (CT) and Cone Beam Computed Tomography (CBCT) are powerful tools to help clinicians on diagnosis and preoperative planning. They provide an accurate view of regional anatomy, anatomical variations and the presence of diseases. Compared to CT, CBCT produces images with adequate spatial resolution with smaller fields of view at lower radiation doses. It has emerged as a potential alternative for obtaining 3D evaluation of the paranasal sinus at relatively modest costs. The aim of this review was to verify whether CBCT images offer an additional value to the evaluation of paranasal sinus

The influence of number of line pairs in digital intra-oral radiography on the detection accuracy of horizontal root fractures

Line pairs are the unit for measurement of resolution and are related to the spatial quality of the system. Thus, the objective of this study was to evaluate the influence of number of line pairs in digital intraoral radiography on the detection accuracy of horizontal root fractures. Materials and Methods: Sixty-four extracted single-root human teeth were used. Thirty-two had horizontal root fractures created and were mounted in dry human mandibles. The teeth were radiographed with two digital receptors: the Digora Optime (14.3 lp mm(-1)) and the Digora Toto (26.3 lp mm(-1)). Images were viewed under standardized conditions by 3 calibrated examiners using the respective dedicated software (Digora for Windows 2.6 (R) and Scanora (R)). Digora Toto (R) images were also evaluated through the Digora for Windows 2.6 (R) software. The results were statistically analyzed based on the area under the ROC curve for each examiner. Results: Pairing Digora Toto (R) with Scanora (R) allowed for greater accuracy in horizontal root fractures diagnosis, while images acquired with that same system seem to lose accuracy when visualized with Digora for Windows 2.6 (R). Pairing Digora Optime (R) with Digora for Windows 2.6 (R) resulted in the lowest accuracy for horizontal root fractures diagnosis. Conclusions: The higher number of line pairs and the consequent higher image resolution provided by the Digora Toto (R) system and its dedicated software seem to enhance the accuracy of horizontal root fractures diagnostic imaging.Line pairs are the unit for measurement of resolution and are related to the spatial quality of the system. Thus, the objective of this study was to evaluate the influence of number of line pairs in digital intraoral radiography on the detection accuracy of horizontal root fractures. Sixty-four extracted single-root human teeth were used. Thirty-two had horizontal root fractures created and were mounted in dry human mandibles. The teeth were radiographed with two digital receptors: the Digora Optime (14.3 lp mm(-1)) and the Digora Toto (26.3 lp mm(-1)). Images were viewed under standardized conditions by 3 calibrated examiners using the respective dedicated software (Digora for Windows 2.6 (R) and Scanora (R)). Digora Toto (R) images were also evaluated through the Digora for Windows 2.6 (R) software. The results were statistically analyzed based on the area under the ROC curve for each examiner. Pairing Digora Toto (R) with Scanora (R) allowed for greater accuracy in horizontal root fractures diagnosis, while images acquired with that same system seem to lose accuracy when visualized with Digora for Windows 2.6 (R). Pairing Digora Optime (R) with Digora for Windows 2.6 (R) resulted in the lowest accuracy for horizontal root fractures diagnosis. The higher number of line pairs and the consequent higher image resolution provided by the Digora Toto (R) system and its dedicated software seem to enhance the accuracy of horizontal root fractures diagnostic imaging32318018

Racionalización de la dosis de radiación

En la actualidad existe una gran aceptación por la medicina y la odontología, en que la práctica clínica debe ser“basada en evidencia científi ca”, tanto como sea posible. Es por eso que múltiples trabajos se han publicadoorientados a disminuir las dosis de radiación en los diferentes tipos de modalidades imaginológicas usados enla odontología, ya que el mayor efecto de las radiaciones, sobre todo en niños, nos obliga a tomar medidas necesariaspara racionalizar su uso, especialmente con la tomografía computarizada Cone Beam (TCCB), métodoque aporta las mayores dosis en la odontología. Esta revisión fue escrita utilizando un enfoque de este tipo conel propósito de racionalizar la dosis de radiación en nuestros pacientes. El equipo del proyecto SEDENTEXCTrecopiló y analizó relevantes publicaciones en la literatura, pautas que han demostrado su efi cacia en el pasado,para llegar a formular recomendaciones que contribuyan a la optimización del uso de las radiaciones ionizantesen la odontología, ayudando de esa manera a ver con otros ojos la dosis recibida por los pacientes, y conla presente se recomienda tener en cuenta dicho documento para poder prescribir de manera más adecuada losexámenes complementarios que usamos diariamente