Tomographic diagnosis of alveolar bone coverage impact in orthodontic planning: cross-sectional study.

INTRODUCTION: Alveolar bone coverage can be diagnosed through cone beam computed tomography (CBCT) and this information can prevent orthodontic tooth movement beyond the biological limit. OBJECTIVE: This study evaluated the impact of the bone coverage (BC) diagnosis by CBCT in the orthodontists' planning. METHODS: One hundred fifty-nine Brazilian orthodontists suggested treatment plans for six patients at two different times, using two sequential questionnaires. The first questionnaire consisted of extra and intra-oral photographs, one panoramic radiograph; one lateral cephalometric radiograph with Steiner and Tweed analysis, and the patient chief complaint. The second questionnaire included the same presentations of cases with tomographic images and the radiologist's report. The McNemar test assessed the difference between the first and the second treatment plans. RESULTS: In all six cases, most participants changed the treatment plan after evaluating the CBCT images and the radiologist's report (93.7% in case 5, 78.6% in case 4, 74.2% in case 3, 69.8% in case 6, 66% in case 2 and 61% in case 1; p≤0.01). CONCLUSION: The evaluation of bone coverage through CBCT images has a substantial impact on the orthodontic diagnosis and planning of the Brazilian orthodontists.

Anatomical study of the maxillary sinus: which characteristics can influence its volume?

PURPOSE: To investigate whether there is a relationship between the volume of the maxillary sinus and individual parameters such as gender, side, posterior tooth absence, sinus membrane thickening, bony septa, vertical and sagittal skeletal patterns. METHODS: The tomographic volume of the maxillary sinus from 211 individuals (422 sides) was evaluated using Horos DICOM Viewer Software. Bony septa and sinus membrane thickening were classified as absent or present. At the same time, loss of one or more teeth in the posterior region of the maxilla (except for the third molars) was considered. The t test was applied to analyze maxillary sinus volume according to gender, age, side, posterior tooth absence, sinus membrane thickening and bony septa. A one-way analysis of variance (ANOVA) with Tukey's post-hoc test was applied to compare sagittal and vertical patterns. Pearson's correlation coefficient was also used to verify the association between maxillary sinus volume, age and skeletal patterns. RESULTS: Concerning the sagittal skeletal pattern, a statistically significant difference was observed between Classes II and III (p = 0.05) and it was confirmed by the Pearson's correlation coefficient (r = - 0.107/p = 0.029). No statistically significant differences were observed between the maxillary sinus volume according to gender (p = 0.06), side (p = 0.37), posterior tooth absence (p = 0.92), sinus membrane thickening (p = 0.47), bony septa (0.89) and vertical skeletal pattern (p = 0.67). No significant differences were observed with age (r = - 0.076/p = 0.109) and the vertical skeletal pattern (r = - 0.078/p = 0.108). CONCLUSION: Maxillary sinus volume was influenced by the sagittal skeletal pattern and was higher in Class III individuals.

Assessment of the relationship between tooth inclination and gingival and alveolar bone dimensions using computed tomography of the maxillary anterior teeth: a cross-sectional study.

OBJECTIVE: The present study aimed to investigate the relationship between tooth inclination and gingival and bone dimensions in maxillary anterior teeth. METHODS: This cross-sectional study included cone-beam computed tomography (CBCT) images of 160 maxillary anterior teeth (30 individuals). Tooth inclination, gingival and bone thickness, and distances from cementoenamel junction to alveolar bone crest and gingival margin were measured in the labial surface. The correlations were analyzed using Pearson and partial correlation tests (p≤0.05). RESULTS: In the central incisors, tooth inclination was positively and significantly related to apical bone thickness (R = 0.34, p= 0.001). In the canines, tooth inclination was negatively and significantly related to cervical bone thickness (R = - 0.34, p= 0.01) and positively associated to apical bone thickness (R = 0.36, p= 0.01) and to gingival margin-cementoenamel junction distance (R = 0.31, p= 0.03). In the lateral incisors, tooth inclination was not associated with gingival or bone dimensions. CONCLUSIONS: In the central incisors, the greater the labial tooth inclination, the greater is the apical bone thickness. In the canines, the greater the labial tooth inclination, the smallest is the cervical bone thickness, the greater is the apical bone thickness, and the greater is the gingival margin. Gingival and bone dimensions should be assessed when planning orthodontic treatment involving buccal movement of central incisors and canines.

Tomographic assessment of infrazygomatic crest bone depth for extra-alveolar miniscrew insertion in subjects with different vertical and sagittal skeletal patterns.

OBJECTIVE: To evaluate bone availability at the infrazygomatic crest for extra-alveolar bone miniscrew insertion in subjects with different vertical and sagittal skeletal patterns. SETTING AND SAMPLE POPULATION: Measurements of the infrazygomatic crest were performed on multislice computed tomography scans from 58 adults with different skeletal patterns. MATERIALS AND METHODS: Infrazygomatic crest bone depth was measured at 4, 5 and 6 mm from the cementoenamel junction (CEJ) of the maxillary first molar at three different angles (60°, 70° and 80°) in the first molar occlusal plane. The sagittal and vertical skeletal patterns were determined. Analysis of variance followed by Tukey's post hoc test was used (P ≤ .05). RESULTS: Bone depth was greater near the CEJ (8.7 ± 3.1 mm) and lower in the apical area (5.8 ± 2.7 mm). In Class II subjects, considering 6 mm from the CEJ, there was a significantly lower depth at the 80° angle (5.4 ± 2.5 mm) than at 60° (8.6 ± 3.5 mm; P = .007). In mesofacial subjects, considering 5 and 6 mm from the CEJ, bone depth was lower at 80° (5.7 ± 3.2 mm and 5.3 ± 2.5 mm) than at 60° considering 4 mm from the CEJ (P ≤ .019). CONCLUSION: Bone availability was lower at the apical level, especially in Class II and mesofacial subjects. Therefore, when the planned insertion site is located in the apical direction, it is recommended to choose shorter miniscrews (2.0 x 12mm) and a smaller insertion angle (60°) and/or to plan a miniscrew bone insertion deep enough to allow bicortical fixation.

Assessment of the relationship between tooth inclination and gingival and alveolar bone dimensions using computed tomography of the maxillary anterior teeth: a cross-sectional study

ABSTRACT Objective: The present study aimed to investigate the relationship between tooth inclination and gingival and bone dimensions in maxillary anterior teeth. Methods: This cross-sectional study included cone-beam computed tomography (CBCT) images of 160 maxillary anterior teeth (30 individuals). Tooth inclination, gingival and bone thickness, and distances from cementoenamel junction to alveolar bone crest and gingival margin were measured in the labial surface. The correlations were analyzed using Pearson and partial correlation tests (p≤0.05). Results: In the central incisors, tooth inclination was positively and significantly related to apical bone thickness (R = 0.34, p= 0.001). In the canines, tooth inclination was negatively and significantly related to cervical bone thickness (R = - 0.34, p= 0.01) and positively associated to apical bone thickness (R = 0.36, p= 0.01) and to gingival margin-cementoenamel junction distance (R = 0.31, p= 0.03). In the lateral incisors, tooth inclination was not associated with gingival or bone dimensions. Conclusions: In the central incisors, the greater the labial tooth inclination, the greater is the apical bone thickness. In the canines, the greater the labial tooth inclination, the smallest is the cervical bone thickness, the greater is the apical bone thickness, and the greater is the gingival margin. Gingival and bone dimensions should be assessed when planning orthodontic treatment involving buccal movement of central incisors and canines.

RESUMO Objetivo: O presente estudo teve como objetivo investigar a relação entre a inclinação dentária e as dimensões ósseas e gengivais em dentes anteriores superiores. Métodos: Esse estudo transversal incluiu imagens de tomografia computadorizada de feixe cônico (TCFC) de 160 dentes anteriores superiores divididos em três grupos (incisivo central, incisivo lateral e canino). Todos os pacientes tinham 18 anos ou mais, não tinham tratamento ortodôntico prévio nem história clínica que pudesse afetar as dimensões ósseas ou gengivais. A inclinação dentária, a espessura do osso e da gengiva e as distâncias da junção cemento-esmalte à crista óssea alveolar e à margem gengival foram medidas na face vestibular. As correlações foram analisadas por meio dos testes de Pearson e de correlação parcial (p≤0,05). Resultados: Nos incisivos centrais, a inclinação dentária foi positiva e significativamente relacionada à espessura do osso apical (R = 0,34, p= 0,001). Nos caninos, a inclinação dentária foi negativa e significativamente relacionada à espessura do osso cervical (R = - 0,34, p= 0,01) e positivamente associada à espessura do osso apical (R = 0,36, p= 0,01) e à distância entre a margem gengival e a junção cemento-esmalte (R = 0,31, p= 0,03). Nos incisivos laterais, a inclinação do dente não foi associada às dimensões do osso ou da gengiva. Conclusões: Nos incisivos centrais, quanto maior a inclinação vestibular do dente, maior a espessura do osso apical. Nos caninos, quanto maior a inclinação vestibular do dente, menor a espessura do osso cervical, maior a espessura do osso apical e maior a margem gengival. As dimensões ósseas e gengivais devem ser avaliadas ao se planejar o tratamento ortodôntico envolvendo a movimentação vestibular dos incisivos centrais e caninos.

Comparison of digital image displays performance in the detection of artificial internal root resorptions lesions.

OBJECTIVE: To compare the diagnostic efficacy of different devices for visualizing digital images in detecting simulated internal root resorption (IRR). METHODS: 26 uniradicular human teeth were sectioned along its long axis and randomly divided into two groups. Then, they were submerged in hydrochloric acid (HCl) P.A 37% at different times to make two types of defects: Type 1 (2 hours), and type 2 (3 hours). Digital periapical radiographs were acquired in three moments: before section, after section and after immersion in acid. The images were evaluated on three different devices: 27-inch iMac Desktop, 8-inch Android Tablet, and 5.5-inch iPhone 8 Plus using a 5-point scale. RESULTS: The sensitivity and accuracy values were higher with the use of the Android Tablet, for both types of defects. For the values of the area under ROC curve, higher results were observed with the Android Tablet and lower results with the iMac, showing a significant difference (p < 0.05) when comparing the use of the iMac with the Android Tablet and iPhone 8, for type 1 defects. When comparing the different devices, in the evaluation of images of type 2 defects, the values showed no statistical difference, regardless of the device evaluated (p > 0.05). CONCLUSIONS: The size of the lesion interferes with the detection capacity in the image. However, the use of portable devices does not impair the diagnosis of IRR, regardless of size and the dental practioners may use different devices/display, under optimal viewing conditions, to detect IRR lesions, without jeopardizing the diagnostic ability.

Computer tomographic differential diagnosis of ameloblastoma and odontogenic keratocyst: classification using a convolutional neural network.

OBJECTIVE: To analyse the automatic classification performance of a convolutional neural network (CNN), Google Inception v3, using tomographic images of odontogenic keratocysts (OKCs) and ameloblastomas (AMs). METHODS: For construction of the database, we selected axial multidetector CT images from patients with confirmed AM (n = 22) and OKC (n = 18) based on a conclusive histopathological report. The images (n = 350) were segmented manually and data augmentation algorithms were applied, totalling 2500 images. The k-fold × five cross-validation method (k = 2) was used to estimate the accuracy of the CNN model. RESULTS: The accuracy and standard deviation (%) of cross-validation for the five iterations performed were 90.16 ± 0.95, 91.37 ± 0.57, 91.62 ± 0.19, 92.48 ± 0.16 and 91.21 ± 0.87, respectively. A higher error rate was observed for the classification of AM images. CONCLUSION: This study demonstrated a high classification accuracy of Google Inception v3 for tomographic images of OKCs and AMs. However, AMs images presented the higher error rate.

Assessment of the mandibular buccal shelf for orthodontic anchorage: Influence of side, gender and skeletal patterns.

OBJECTIVES: To evaluate bone height and thickness in the mandibular buccal shelf region and to compare differences between anatomical sites according to gender, side and vertical and sagittal skeletal patterns. SETTINGS AND SAMPLE POPULATION: Multislice computed tomography (MSCT) images of 94 subjects (51 females and 43 males) were previously obtained as part of preoperative planning for orthognathic surgery. METHODS: Measurements were performed in three different regions of the mandibular buccal shelf: mesially, towards the central groove and distally to the second molars. Bone thickness measurements were obtained perpendicularly 3, 5 and 7 mm below the bone crest towards the mandible outer cortex. Bone height was measured 3 mm away from the bone crest perpendicularly to the outer cortex of the base of mandible. RESULTS: There was an increase in bone thickness in the posterior and basal directions. The increase in bone thickness ranged from 1.8 to 7.1 mm. Greater bone height was found in the anterior direction. The increase in bone height ranged from 17.5 to 22.5 mm. Hypodivergent and Class III subjects showed significantly greater bone thickness (P < .05). Significantly greater bone height was found mesially to the second molar in Class III subjects compared with Class I subjects (P < .05) and in hyperdivergent males compared with hypodivergent males (P < .05). CONCLUSIONS: The region distal to the second molar is the most appropriate for the insertion of extra-alveolar mini-screws in terms of bone thickness. Hypodivergent and Class III subjects showed greater bone thickness in the mandibular buccal shelf region.

Assessment of fractal dimension and panoramic radiomorphometric indices in women with celiac disease.

OBJECTIVES: To assess the panoramic radiomorphometric indices and fractal dimension in women with celiac disease. METHODS: The sample consisted of 20 women with celiac disease and 20 healthy women (control group). The mandibular cortical index classification, panoramic mandibular index, mental index, and fractal dimension were evaluated on panoramic radiographs. One-way ANOVA with post hoc Tukey test was used for comparison of the linear measurements and fractal dimension between the celiac and control groups, adopting a significance level of 5% RESULTS: There was no significant difference in panoramic radiomorphometric indices or fractal dimension between the celiac and control groups. CONCLUSIONS: Panoramic radiomorphometric indices and fractal dimension revealed no significant bone changes in women with celiac disease.

Avaliação clínica, radiográfica e tomográfica de fraturas radiculares: série de casos / Clinical, radiographic and tomographic evaluation of root fractures: case series

Introdução: o diagnóstico de fratura radicular é difícil, pois não há sinais/sintomas clínicos e características radiográficas patognomônicas, podendo ser confundido com um insucesso no tratamento endodôntico e até mesmo com doença periodontal. Objetivo: descrever as características clínicas, radiográficas e tomográficas em dentes com suspeita de fratura radicular. Métodos: a amostra foi composta por seis indivíduos cujos dados clínicos foram coletados, realizados testes de percussão vertical e horizontal, verificando se o dente apresentava mobilidade dentária e bolsa periodontal. Achados radiográficos e tomográficos foram avaliados em relação à presença de fratura radicular e de lesão periapical e/ou perda óssea associada ao terço apical/lateral da raiz para se obter o diagnóstico complementar da fratura radicular. Resultados: os achados clínicos mais prevalentes foram percussões vertical e horizontal positivos seguidos de dor e mobilidade. Os exames por imagem evidenciaram que todos os casos de suspeita de fratura radicular estavam relacionados a dentes com pino metálico. Em apenas um caso, não foi possível visualizar a lesão periapical e/ou perda óssea e a fratura na radiografia periapical, sendo detectadas nas imagens tomográficas. Conclusões: os achados clínicos de suspeita de fraturas radiculares são muito variáveis, necessitando correlacioná-los com exames de imagem. A TCFC se mostrou mais eficaz que a radiografia periapical na detecção da linha de fratura, porém esses dois exames podem ser utilizados para complementar o exame clínico e alcançar um diagnóstico mais acurado..

Introduction: the diagnosis of dental fracture is usually difficult because there are no pathognomonic clinical signs/symptoms and radiographic characteristics, and may be mistaken for failure of endodontic treatment and even periodontal disease. Purpose: to describe clinical, radiographic and tomographic characteristics in teeth with suspected root fracture. Methods: the sample consisted of 06 individuals and their clinical data were collected. Vertical and horizontal percussion tests were performed, verifying tooth mobility and periodontal pocket. In relation to radiographic and tomographic findings, the presence of root fracture and periapical lesion and/or bone loss associated with the apical/lateral third of the root were evaluated in order to obtain the diagnosis of root fracture. Results: the most prevalent clinical findings were positive vertical and horizontal percussions followed by pain and mobility. Imaging tests showed that all cases of suspected root fracture were related to teeth with metallic post. In only one case, it was not possible to visualize the periapical lesion and/or bone loss and fracture in the periapical radiography, being detected in tomographic images. It`s possible to conclude with the analysis of some clinical cases that cone-beam computed tomography favors accuracy and precision regarding the visualization, location and extension of root fracture, as well as periapical alterations. Conclusions: the clinical findings of suspected root fractures are very variable, requiring to correlate them with imaging exams. The CBCT was more effective than the periapical radiography in the detection of the fracture line, but these two exams can be used to complement the clinical examination and reach a more accurate diagnosis.

Cone beam computed tomography devices in the evaluation of buccal bone in anterior teeth.

OBJECTIVE: To determine the accuracy of various cone beam computed tomography (CBCT) devices in assessing the buccal bone in anterior teeth. MATERIAL AND METHODS: A skull encased in tissue equivalent material was imaged with six CBCT devices: 3D Accuitomo 170 (J. Morita, Japan), CS 9000 3D (Carestream Dental, France), CS 9300 (Carestream Dental, France), Eagle 3D (Dabi Atlante, Brazil), i-CAT Classic (Imaging Sciences International, USA) and Orthophos XG 3D (Sirona Dental System, USA). The exposure and acquisition protocols were determined using the manufacturer's guidelines, the voxel size adjusted as close as possible to 0.2 mm. Cross-sectional images were evaluated randomly, and the buccal bone was assessed. RESULTS: The statistics were calculated based on a logistic regression model with the significance level set at 5%. All CBCT devices showed high accuracy; however, observers noted that the accuracy and sensitivity of CS 9300 device were slightly superior. CONCLUSION: The diagnostic performance of all CBCT devices was high for the evaluation of buccal bone in anterior teeth. When the clinical usefulness of an imaging modality is equivalent, the choice of appropriate imaging should be directed towards the modality that delivers the least radiation dose to the patient for a specific diagnostic task.

Assessing bone thickness in the infrazygomatic crest area aiming the orthodontic miniplates positioning: a tomographic study.

INTRODUCTION:: Due to the increasing use of miniplates for anchorage purposes in orthodontics, it is very important to know more about infrazigomatic crest anatomy (thickness), in adult patients. OBJECTIVES:: Evaluate the infrazygomatic crest region thickness, in adult (male and female) patients. METHODS:: Cone-beam computerized tomography (CBCT) images from 40 patients were used to assess cross-sectional measurements of the infrazygomatic crest region. Measurement 1 considered thickness 2 mm above the distobuccal root of the permanent maxillary first molar, while measurement 2 was taken 2 mm above the first measurement. RESULTS:: The mean thickness of the infrazygomatic crest in males was 3.55 mm for measurement 1 and 2.84 mm for measurement 2, while in females these were 2.37 mm and 2.24 mm, respectively. CONCLUSION:: The authors concluded that the overall mean thickness of the infrazygomatic crest was 2.49 mm with respect to measurement 1, and 2.29 mm for measurement 2, with no statistically significant differences between gender.

Assessing bone thickness in the infrazygomatic crest area aiming the orthodontic miniplates positioning: a tomographic study

ABSTRACT Introduction: Due to the increasing use of miniplates for anchorage purposes in orthodontics, it is very important to know more about infrazigomatic crest anatomy (thickness), in adult patients. Objectives: Evaluate the infrazygomatic crest region thickness, in adult (male and female) patients. Methods: Cone-beam computerized tomography (CBCT) images from 40 patients were used to assess cross-sectional measurements of the infrazygomatic crest region. Measurement 1 considered thickness 2 mm above the distobuccal root of the permanent maxillary first molar, while measurement 2 was taken 2 mm above the first measurement. Results: The mean thickness of the infrazygomatic crest in males was 3.55 mm for measurement 1 and 2.84 mm for measurement 2, while in females these were 2.37 mm and 2.24 mm, respectively. Conclusion: The authors concluded that the overall mean thickness of the infrazygomatic crest was 2.49 mm with respect to measurement 1, and 2.29 mm for measurement 2, with no statistically significant differences between gender.

RESUMO Introdução: devido ao aumento do uso de miniplacas para ancoragem em Ortodontia, torna-se de fundamental importância compreender melhor a anatomia da crista infrazigomática (espessura) em pacientes adultos. Objetivos: avaliar a espessura da crista infrazigomática em pacientes adultos (sexos feminino e masculino). Métodos: foram utilizadas tomografias computadorizadas de feixe cônico (TCFC) de 40 pacientes, para avaliar medidas da região da crista infrazigomática, no sentido transversal. A Medida 1 verificou a espessura mm acima da raiz distovestibular do primeiro molar permanente superior, enquanto a Medida 2 foi realizada 2 mm acima da primeira medida. Resultados: a espessura média da crista infrazigomática encontrada no sexo masculino foi de 3,55 mm para a Medida 1 e de 2,84 mm para a Medida 2, e no sexo feminino foi de 2,37 mm e de 2,24 mm, respectivamente. Conclusão: os autores puderam constatar que a espessura média da crista infrazigomática foi de 2,49 mm para a Medida 1, e de 2,29 mm para a Medida 2, sem diferença estatisticamente significativa entre os sexos.

Evaluation of the oropharynx in class I and II skeletal patterns by CBCT.

PURPOSE: This study aimed to evaluate the dimensions of the oropharynx and its shape in the minimum cross-sectional area, in individuals with Class I and Class II skeletal patterns, using three-dimensional CBCT images. METHODS: Forty-two cone-beam computed tomography images of grown individuals were evaluated. The images were divided according to the patient's skeletal patterns. The dimensions of the oropharyngeal airway space were determined using the Dolphin Imaging software. RESULTS: The volume and the minimum cross-sectional area were greater in patients with a Class I skeletal pattern, with a median difference of 5379 mm3 and 86.8 mm2, respectively. The anteroposterior and lateral diameters in the minimum cross-sectional area were also higher in Class I individuals (2.3 and 6.0 mm, respectively), but the ratio between them was not different. CONCLUSIONS: The volume and the minimum cross-sectional area of the oropharynx, as well as the anteroposterior and lateral diameters, are lower in individuals with a class II skeletal pattern than in individuals with a class I skeletal pattern. There was no difference in the shape of the oropharynx in healthy individuals with different skeletal patterns.

Brown tumor of secondary hyperparathyroidism: surgical approach and clinical outcome.

BACKGROUND: Secondary hyperparathyroidism is a frequent complication of chronic renal failure. The brown tumor is an unusual presentation of fibrous osteitis that represents a serious complication of renal osteodystrophy, affecting predominantly the hands, feet, skull, and facial bones. CASE REPORT: The aim of this paper is to describe the case of a 53-year-old female patient, with renal failure who has been on dialysis for 6 years and developed severe secondary hyperparathyroidism and brown tumor of the maxilla and mandible, confirmed by incisional biopsy. Parathyroidectomy was indicated as a result of rapid growth of the tumor and the maintenance of laboratory findings. Despite the normalization of serum parathyroid hormone and alkaline phosphatase, tumor regression was slow and patient's important functional and esthetic deficits persisted. Excision of the mandible tumor was conservative. Osteoplasty was recommended because during a 5-year follow-up there was regression of the lesion, decreased pain, bleeding, and tooth mobility.

Trifid nasopalatine canal: case report of a rare anatomical variation and its surgical implications / Conducto nasopalatino Trifid: presentación de caso de una variación anatómica rara y sus implicaciones quirúrgicas

The nasopalatine canal is a long slender structure present in the midline of the anterior maxilla that connects the palate to the floor of the nasal cavity. The nasopalatine canal contains the nasopalatine nerve, the terminal branch of the nasopalatine artery, fibrous connective tissue, adipose tissue, and minor salivary glands. The purpose of this article was to report a case of a trifid nasopalatine canal detected by cone beam computed tomography prior to dental implant placement. A 47-year-old female patient was submitted to cone beam computed tomography. Axial and sagittal sections revealed a trifurcation of the nasopalatine canal. Each canal was separated from the other by bony septa and extended independently from the floor of the nasal cavity to the incisive foramen in the remnant of the alveolar process in the anterior region of the maxilla. Cone beam computed tomography has permitted better visualization of the details and anatomical variations of the nasopalatine canal. Detailed knowledge of variations in the shape, number and size of the nasopalatine canal is fundamental for surgical procedures, such as local anesthesia in the anterior maxillary region and placement of dental implants, in order to prevent damage to important arteries and nerves(AU)

El canal nasopalatino es una larga estructura delgada presente en la línea media del maxilar anterior que conecta el palato al suelo de la cavidad nasal. El canal nasopalatino contiene el nervio nasopalatino, la rama terminal de la arteria nasopalatina, el tejido conectivo fibroso, el tejido adiposo y las glándulas salivales menores. El propósito de este artículo es presentar el caso de un canal nasopalatino trifid detectado a través de tomografía computarizada de haz cónico anterior a la colocación de implantes dentales, en una paciente de femenino 47 años de edad. Secciones axiales y sagitales revelaron la trifurcación del canal nasopalatino. Cada canal se apartó del otro por tabiques ósea y extendida independientemente del suelo de la cavidad nasal para el agujero incisivo en el remanente del proceso alveolar en la región anterior del maxilar. La tomografía computarizada de haz cónico ha permitido una mejor visualización de los detalles y variaciones anatómicas del canal nasopalatino. El conocimiento detallado de las variaciones en su forma, el número y el tamaño del canal nasopalatino es fundamental para los procedimientos cirúrgicos, así como la anestesia local en la región anterior del maxilar superior y la colocación de los implantes dentales, con el fin de prevenir el daño a las arterias y a los nervios importantes(AU)

Canal transportation and centering ability of curved root canals prepared using rotary and reciprocating systems

Abstract Aim: To evaluate canal transportation and centering ability of Protaper and WaveOne systems in curved root canals by cone-beam computed tomography. Methods: Twenty human molars were randomly divided into two groups according to the system used: Group GP (ProTaper Universal(r)) and group GW (WaveOne(tm)). CT scans were performed before and after the chemo-mechanical preparation on three points: 2 mm, 3 mm and 4 mm from the tooth apex. The cuttings in dentin were measured and results were statistically analyzed. Results: In GP, there was higher percentage in transport at 2 mm and 4 mm toward the mesial wall of the tooth root compared to GW (p<0.05). There was no difference between the systems regarding their centering ability. Conclusions: None of the systems was able to touch all the dentin walls and stay centered during the chemical-mechanical preparation.

Accessory mental foramen: A rare anatomical variation detected by cone-beam computed tomography.

The mental foramen is a bilateral opening in the vestibular portion of the mandible through which nerve endings, such as the mental nerve, emerge. In general, the mental foramen is located between the lower premolars. This region is a common area for the placement of dental implants. It is very important to identify anatomical variations in presurgical imaging exams since damage to neurovascular bundles may have a direct influence on treatment success. In the hemimandible, the mental foramen normally appears as a single structure, but there are some rare reports on the presence and number of anatomical variations; these variations may include accessory foramina. The present report describes the presence of accessory mental foramina in the right mandible, as detected by cone-beam computed tomography before dental implant placement.

O impacto do biotipo gengival nas reabilitações implantossuportadas na zona estética – conhecimentos atuais / The impact of gingival biotype on implant-supported prostheses in the anterior esthetic zone – current knowledge

O objetivo deste artigo foi realizar uma revisão da literatura demonstrando o impacto do biótipo gengival na composição estética e funcional das reabilitações com implantes na região anterior da maxila. O biotipo tecidual ao redor de implantes pode ser classificado como fino ou espesso. Estes biotipos estão associados a diferentes características clínicas, podendo resultar em comportamentos divergentes pós-tratamento com implantes. O biotipo gengival espesso está relacionado com menores índices de complicações estéticas, como a recessão, e maior estabilidade óssea. Desta forma, o diagnóstico do biotipo tecidual durante a fase de planejamento deverá ser inserido na rotina clínica, devendo ser selecionado um método de diagnóstico eficaz, reprodutível, pouco oneroso e pouco invasivo. A partir de um correto diagnóstico, existe a possibilidade da conversão do biotipo fino para espesso através de técnicas cirúrgicas de manejo do tecido mole e da prótese. Portanto, o diagnóstico e a conversão de biotipos finos poderão resultar em maior previsibilidade estético-funcional das reabilitações implantossuportadas.

The tissue biotype around implants can be classifi ed as thin or thick. These biotypes are associated with different clinical characteristics and may result in different behaviors after treatment with implants. The thick gingival biotype is associated with lower rates of aesthetic complications, as well as recession and increased bone stability. Thus, the diagnosis of tissue biotype during the planning phase should be inserted in the clinical routine and it must be an effective, reproducible, inexpensive and less invasive method. From a correct diagnosis, a conversion from thin to thick biotype through surgical techniques and soft tissue prosthesis management is possible. Therefore, diagnosis and conversion of thin biotypes may result in greater aesthetic and functional predictability of implant restorations.