Tomographic analysis of midpalatal suture prior to rapid maxillary expansion

ABSTRACT Introduction: In Orthodontics and Facial Orthopedics, the timing of treatment onset may be critical and individual analysis should be applied to promote a favorable treatment planning. In this study, individual analysis of midpalatal suture (MS) and palatal measurements were performed in teenagers and young adult patients treated with rapid maxillary expansion (RME). Description: Twenty-six patients submitted to RME with a tooth-supported appliance (Hyrax) were evaluated. The inclusion criteria were: minimum age of 14 years, presenting all posterior teeth, diagnosed with transverse maxillary discrepancy, and with a clinical indication for maxillary expansion. The pretreatment CBCT scans of these patients were assessed to obtain the stages of MS maturation (MSM); density ratio (MSD); and palatal length, thickness (anterior, intermediate and posterior) and sagittal area. Results: The maturation stages present were C, D or E; the density ranged from 0.6 to 1, and lower density (MSD < 0.75) and higher density (MSD ≥ 0.75) groups were determined. Individuals with higher MSD presented smaller sagittal area, compared to the lower density group. Individuals in D and E MSM stages presented smaller sagittal area and intermediate thickness, compared to stage C. Conclusions: Smaller palatal sagittal area was observed in the high MSD groups and in the stages D and E of MSM.

RESUMO Introdução: Em Ortodontia e Ortopedia Facial, o momento de início do tratamento pode ser crítico, e uma análise individual deve ser aplicada para promover um planejamento de tratamento favorável. No presente estudo, foram realizadas a avaliação individualizada da sutura palatina mediana (SPM) e medições no palato de adolescentes e adultos jovens tratados com expansão rápida da maxila (ERM). Descrição: Foram avaliados vinte e seis pacientes submetidos à ERM com aparelho dentossuportado (Hyrax). Os critérios de inclusão foram: idade mínima de 14 anos, apresentando todos os dentes posteriores, diagnosticado com discrepância transversa da maxila e com uma indicação clínica para expansão maxilar. A tomografia computadorizada de feixe cônico (TCFC) pré-tratamento desses pacientes foi avaliada para obter os estágios de maturação da SPM (MSPM), densidade da SPM (DSPM), comprimento do palato, espessura (anterior, intermediária e posterior) e área sagital. Resultados: Os estágios de maturação presentes foram C, D ou E; a densidade variou de 0,6 a 1, e foram determinados grupos de baixa (DSPM < 0,75) e alta densidade (DSPM ≥ 0,75). Indivíduos com maior DSPM apresentaram menor área sagital, em comparação com o grupo de densidade mais baixa. Indivíduos nos estágios D e E de MSPM apresentaram menor área sagital e espessura intermediária, comparados aos indivíduos no estágio C. Conclusão: Uma menor área sagital palatina foi observada nos grupos de alta DSPM e nos estágios D e E de MSPM.

Root canal segmentation in cone-beam computed tomography: comparison with a micro-CT gold standard

Aim: The purpose of this study was to compare root canal volumes (RCVs) obtained by means of cone beam computed tomography (CBCT) to those obtained by micro-computed tomography (micro-CT) after applying different segmentation algorithms. Methods: Eighteen extracted human teeth with sound root canals were individually scanned in CBCT and micro-CT using specific acquisition parameters. Two different images segmentation strategies were applied to both acquisition methods (a visual and an automatic threshold). From each segmented tooth, the root canal volume was obtained. A paired t-test was used to identify differences between mean values resulted from the experimental groups and the gold standard. In addition, Pearson correlation coefficients and the agreement among the experimental groups with the gold standard were also calculated. The significance level adopted was 5%. Results: No statistical differences between the segmentation methods (visual and automatic) were observed for micro-CT acquired images. However, significant differences for the two segmentation methods tested were seen when CBCT acquired images were compared with the micro-CT automatic segmentation methods used. In general, an overestimation of the values in the visual method were observed while an underestimation was observed with the automatic segmentation algorithm. Conclusion: Cone beam computed tomography images acquired with parameters used in the present study resulted in low agreement with root canal volumes obtained with a micro-CT tomography gold standard method of RCV calculation

Evaluation of Maxillary Sinus Septa Prior to Dental Implant Therapy: A Cone Beam Computed Tomography Study / Evaluación del Septo del Seno Maxilar Antes del Tratamiento con Implantes Dentales: Un Estudio con Tomografía Computarizada de Haz Cónico

SUMMARY: The objective of this study was to investigate the prevalence and location of maxillary sinus septa prior to dental implant therapy in different age groups by cone beam computed tomography (CBCT) and identify the most helpful orthogonal plane for this purpose. CBCT scans of 200 patients were selected. The final sample was divided into four groups according to age: (1) 30-39 y.o.; (2) 40-49 y.o.; (3) 50-59 y.o.; (4) +60 y.o. Three calibrated examiners assessed the presence and location (anterior, middle, posterior) of sinus septa using all orthogonal slices. The prevalence of septa per region and plane was compared by chi-square test. Among 359 maxillary sinuses evaluated, it was observed at least one septum in 163 sinuses (45.4 %). Overall, the anterior region was the most prevalent. However, when the age groups were considered, the anterior region was only the most prevalent in groups 2 and 3. The middle and posterior regions were more prevalent in groups 4 and 1, respectively. In conclusion, the prevalence of maxillary sinus septa in patients who were candidate to dental implant therapy was notably high. It was observed that the anterior region of the sinus was the most prevalent and the axial slice was the most representative.

RESUMEN: El objetivo de este estudio fue investigar la prevalencia y localización del septo del seno maxilar antes del tratamiento con implantes dentales en diferentes grupos etarios, por medio de la Tomografía Computarizada de Haz Cónico (TCHC). Fueron seleccionadas TCHC de 200 pacientes. La muestra final fue dividida en cuatro grupos de acuerdo con la edad: (1) 30-39 años; (2) 40-49 años; (3) 50-59 años y (4) +60 años. Tres examinadores calibrados evaluaron la presencia y localización (anterior, media o posterior) del septo del seno maxilar usando todas las secciones ortogonales. La prevalencia del septo por región y plano fue comparada mediante el test x-cuadrado. Entre los 359 senos maxilares evaluados, fue observado por lo menos un septo en 163 senos (45,4 %). Generalmente la región anterior fue la más prevalente. Sin embargo, cuando fueron considerados los grupos etarios, solamente la región anterior fue la más prevalente en los grupos 2 y 3. Las regiones media y posterior fueron las más prevalente en los grupos 4 y 1, respectivamente. La prevalencia del septo del seno maxilar en pacientes que son candidatos a tratamiento con implantes dentales fue notablemente alta. Se observó que la región anterior fue la más prevalente siendo las secciones axiales las más representativas.

Automatic cephalometric analysis: is it time to switch to a hands-free method?

Aim: To evaluate the reliability of the automatic cephalometric analysis in relation to the semi-automatic method. Methods: Fifty lateral cephalometric radiographs were selected and two dental surgeons performed the Steiner and Tweed analyses independently using the semi-automatic method on the Radiocef Studio 2® software suite (Radiomemory, Belo Horizonte, MG, Brazil), and the automatic method on the Kodak Dental Imaging Software (Carestream Health, Rochester, NY, USA). After thirty days, 30% of the sample was re-evaluated to assess intra-observer agreement. Ten angular and linear measurements of both analyses were selected, averaged for both observers and compared using Student's t-test with a significance level of 5% (α=0.05). Intra and inter-observer agreement were assessed through Intraclass Correlation Coefficient. Results: Intra-observer reproducibility was excellent for all measurements and inter-observer reproducibility was excellent for most of them. Significant differences (p<0.05) were found between automatic and semi-automatic methods for all measurements. Most of the measurements were significantly higher (p<0.05) with the automatic method. Conclusion: Semi-automatic cephalometric analysis can not be replaced with a completely automatic method

Pre-interruptive intracoronal resorption: clinical and radiographic follow-up / Reabsorção intracoronária pré-eruptiva: acompanhamento clinico e radiográfico

ABSTRACT Pre-interruptive intracoronal resorption is a radiolucent lesion localized in dentin, immediately below the amelodentin junction of unerupted teeth. It is rare, asymptomatic, and of idiopathic etiology, generally diagnosed in routine radiographs or in those for orthodontic purposes. A conservative approach, with radiographic follow-up is the treatment recommended until the tooth erupts, and then the intervention is made. However, in cases with symptoms or progression of the lesion, surgical intervention is advisable. To report a case of pre-interruptive intracoronal resorption, with a conservative approach, showing the clinical and radiographic follow-up of this condition. The patient, a nine-year-old Caucasian girl, presented to the Dental Clinic for routine examination. An initial panoramic radiograph was requested, which showed an intracoronal radiolucence in tooth 45 that had not yet erupted. Clinical and radiographic follow-up was made until the affected tooth was completely established in the oral cavity. The treatment recommended for pre-interruptive intracoronal resorption is to have knowledge of the phenomenon, associate its probable etiology and radiographic aspect, as well as its prevalence, occurrence and treatment options, by considering a conservative approach when there are no symptoms.

RESUMO A reabsorção intracoronária pré-eruptiva é uma lesão radiolúcida localizada na dentina, logo abaixo da junção amelo-detinária de dentes não irrompidos. É rara, assintomática e de etiologia idiopática, geralmente diagnosticada em exames radiográficos de rotina ou com fins ortodônticos. Uma abordagem conservadora com acompanhamento radiográfico é o tratamento recomendado até que o dente erupcione para ser feita a intervenção. Porém, em casos de sintomatologia ou progressão da lesão, aconselha-se a intervenção cirúrgica. Objetivo: Relatar o caso de reabsorção intracoronária pré-eruptiva, com uma abordagem conservadora mostrando a o acompanhamento clínico e radiográfico periódico desta condição. Paciente, sexo feminino, nove anos de idade, caucasiana, que compareceu a Clínica Odontológica para exame de rotina. Foi solicitada uma radiografia panorâmica inicial, sendo evidenciada uma radioluscência intracoronária no dente 45 ainda não erupcionado. Foi feito uma acompanhamento clínico e radiográfico até na total estabelecimento do dente acometido na cavidade oral. Conhecer a reabsorção intracoronária pré-eruptiva, associando sua provável etiologia e aspecto radiográfico, bem como sua prevalência e ocorrência e opções de tratamento, considerando uma abordagem conservadora, quando não houver sintomatologia, como tratamento recomendado.

Tomografía computarizada de haz cónico como instrumento complementario de diagnóstico y planeamiento quirúrgico de quiste dentígero: reporte de un caso / Cone-Beam computed tomography as complementary tool in diagnosis and surgical planning of dentigerous cyst: case report

El quiste dentígero es una de las patologías óseas que más frecuentes en el maxilar y la mandíbula. Se evidencia radiográficamente como una imagen radiolúcida y unilocular en la mayoría de los casos. Generalmente es detectado en exámenes de rutina o cuando se investiga la presencia de dientes no erupcionados. El quiste dentígero aparece principalmente en las tres primeras décadas de vida, con crecimiento lento y asintomático. Los terceros molares,así como dientes supernumerarios, pueden estar relacionados con su formación, sin embargo, su etiopatología no es totalmente conocida. La descompresión, marsupialización y la enucleación son las principales formas de tratamiento, pero algunos criterios deben ser considerados, como tamaño del quiste, edad del paciente, proximidad con estructuras anatómicas nobles e importancia clínica del diente involucrado. Para que se establezca un correcto diagnóstico y plan de tratamiento es esencial la utilización de exámenes complementarios de calidad, siendo, actualmente, la tomografía computarizada de haz cónico el más completo y preciso método de diagnóstico por imagen empleado en estas lesiones. El objetivo de este estudio fue resaltar, por medio de la presentación de un caso clínico, la importancia de la tomografía computarizada de haz cónico en el diagnóstico y planeamiento quirúrgico de un quiste dentígero asociado a un diente no erupcionado

The dentigerous cyst is one of the most frequently found in the jaws. They present themselves radiographically as radiolucent images and more commonly unilocular. They are usually observed at routine checkups or when investigating the presence of unerupted teeth. The dentigerous cyst occurs mainly in the first three decades of life, their growth is slow and asymptomatic. The third molars, as well as supernumerary teeth may be involved with the formation of a dentigerous cyst, but its pathogenesis is still not fully known. Decompression, marsupialization and enucleation are the main forms of treatment, but some criteria must be considered for the treatment plan, such as cyst size, age, proximity to noble anatomical structures and clinical importance of the tooth involved.In order to establish a correct diagnosis and treatment plan is essential to make use of complementary exams and now a days the cone beam computed tomography is the most complete and accurate method in diagnostic imaging used in these situations. Therefore, the aim of this study was to highlight, through the presentation of a clinical case, the importance of cone beam computed tomography in the diagnosis and treatment planning of a dentigerous cyst