Correlation between temporomandibular joint morphometric measurements and gender, disk position, and condylar position.

OBJECTIVE: The aim of this study was to correlate the morphometric measurements of the temporomandibular joint, including condylar size, joint space, and articular eminence size, with gender, disk position, and condylar position by using magnetic resonance imaging. STUDY DESIGN: Overall, 93 patients were evaluated (31.2% males and 68.8% females; age 18-81 years; mean age 41 years). Condylar size (D1), joint space (D2), and eminence size (D3) were measured. Correlations with gender, disk position, and condylar position were calculated. RESULTS: A statistically significant correlation was found between D2 and gender, with the joint space being significantly larger in the male group (P = .05). There were correlations between D2 and the position of the disk and the position of the condyle (P ≤ .05). CONCLUSIONS: The results indicate a correlation between male gender and larger joint space. In addition, we found that the joint space size influences the articular disk and condyle position, which can cause disk displacement.

The effect of different exposure parameters on proximal caries detection using the Kodak 9000 3D CBCT system / Efeito de diferentes parâmetros de exposição na detecção de cáries proximais usando o sistema Kodak 9000 3D TCFC

ABSTRACT Objective: The objective of study was to evaluate the diagnostic quality of CBCT images for caries lesions detection using different exposure parameters. Methods: Sixty extracted human teeth were selected and scanned using Kodak 9000 3D CBCT system, with the following exposure parameters combinations: 74 kV, 10mA; 74 kV, 12mA; 74 kV, 8 mA; 70 kV, 10 mA; 70kV, 12 mA; 70 kV e 8 mA; 70 kV, 6.3 mA. Two observers evaluated the images for caries presence using CS 3D Imaging Software. Each observer scored the proximal surfaces of each tooth on a 5-point scale. The scores were compared to histological sections used as gold standard. Accuracy for caries lesion detection was assessed for each exposure parameter combination and evaluated by means of ROC curve analysis. Results: The mean values for the areas under the ROC curves for each exposure parameter combination varied from 0.35 to 0.60. There was no statistical significant difference among protocols 1, 2, 4, 6 and 7. However, protocols 3 and 5 differed from all protocols. Conclusion: Although the highest dose protocol was the most efficient for proximal caries detection, the lowest dose protocol should be chosen based on the ALADA principle.

RESUMO Objetivo: Avaliar a qualidade de diagnóstico de imagens de TCFC para detecção de lesões de cárie utilizando parâmetros de exposição diferentes. Métodos: Sessenta dentes humanos extraídos foram selecionados e digitalizados usando o sistema Kodak 9000 3D TCFC, com as seguintes combinações de parâmetros de exposição: 74 kV, 10 mA; 74 kV, 12 mA; 74 kV, 8 mA70 kV, 10 mA; 70 kV, 12 mA; 70 kV e 8 mA; 70 kV, 6,3 mA. Dois observadores avaliaram as imagens para a presença de cárie utilizando o CS 3D Imaging Software. Cada observador pontuou as superfícies proximais de cada dente em uma escala de 5 pontos. Os escores foram comparados com cortes histológicos, utilizados como padrão-ouro. A precisão para detecção de lesões de cárie foi analisada para cada combinação de parâmetros de exposição e avaliada por meio de análise da curva ROC. Resultados: Os valores médios para as áreas sob as curvas ROC para cada combinação de parâmetro de exposição variou de 0,35-0,60. Não houve diferença estatística significativa entre os protocolos 1, 2, 4, 6 e 7. No entanto, os protocolos 3 e 5 diferem de todos os protocolos. Conclusão: Embora o protocolo de dose mais elevada foi o mais eficiente para a detecção da cárie proximal, o protocolo de dose mais baixa deverá ser escolhido com base no princípio ALADA.

Relationship between articular eminence inclination and alterations of the mandibular condyle: a CBCT study.

This study aimed at verifying the correlation among angulation of the articular eminence (AE), shape of the condyle and its degenerative bone diseases (DBDs), according to age and sex, through Cone Beam Computed Tomography (CBCT). Five hundred and twenty-eight temporomandibular joints (TMJ) were evaluated. The condyles were classified as: flat, convex, angled and rounded, and the AE angulation was measured. The DBDs evaluated were osteophytes, flattening, erosion, subcortical cysts and spinal sclerosis. There was no difference in the mean angulations in relation to age group (p>0.05). In age groups of 60-69 years (p=0.003) and 70 years or over (p=0.021), the angulation was higher in males. There was an association between DBD and sex (p=0.047), in that the prevalence was higher in females. Differences in AE angles were not observed in condyles with one or no DBDs (p>0.05). However, the presence of two or more DBDs led to a decrease in the angle (p<0.05). Angled condyles showed higher AE angulations than the flat and convex types (p<0.01). In conclusion, the AE inclination is influenced by DBD and condyle shape; an association of two or more bone diseases in the condyle, or its flat or convex anatomy, results in a decrease in the angulation.

Relationship between articular eminence inclination and alterations of the mandibular condyle: a CBCT study

Abstract This study aimed at verifying the correlation among angulation of the articular eminence (AE), shape of the condyle and its degenerative bone diseases (DBDs), according to age and sex, through Cone Beam Computed Tomography (CBCT). Five hundred and twenty-eight temporomandibular joints (TMJ) were evaluated. The condyles were classified as: flat, convex, angled and rounded, and the AE angulation was measured. The DBDs evaluated were osteophytes, flattening, erosion, subcortical cysts and spinal sclerosis. There was no difference in the mean angulations in relation to age group (p>0.05). In age groups of 60-69 years (p=0.003) and 70 years or over (p=0.021), the angulation was higher in males. There was an association between DBD and sex (p=0.047), in that the prevalence was higher in females. Differences in AE angles were not observed in condyles with one or no DBDs (p>0.05). However, the presence of two or more DBDs led to a decrease in the angle (p<0.05). Angled condyles showed higher AE angulations than the flat and convex types (p<0.01). In conclusion, the AE inclination is influenced by DBD and condyle shape; an association of two or more bone diseases in the condyle, or its flat or convex anatomy, results in a decrease in the angulation.

Mucopolysaccharidosis: radiographic findings in a series of 16 cases.

OBJECTIVES: To investigate the radiographic findings of mucopolysaccharidoses (MPS) on panoramic radiographs in a series of 16 patients. STUDY DESIGN: This retrospective cross-sectional study included panoramic radiographs of 16 patients with cytogenetically diagnosed MPS. Two blinded, previously calibrated observers evaluate the presence or absence of the following features: type of dentition; stage of dental age in comparison with chronologic age; delayed exfoliation of deciduous teeth; supernumerary teeth; teeth impaction; enlarged, cyst-like dental crypt; hypercementosis; taurodontism; generalized enamel hypoplasia; enlargement of the bone marrow spaces; thinning of cortical bone; unusual morphology of condyles; and flattening of the condylar head. RESULTS: The final sample was composed of 8 MPS IV, 7 MPS VI, and 1 MPS I cases. All patients presented unusual morphology of condyles. Cyst-like dental crypt (75%), taurodontism, and teeth impaction (68.75% each) were also overall common findings. Generalized enamel hypoplasia was exclusively identified in patients with MPS IV (75% of those patients). CONCLUSIONS: Radiographic features of oral and maxillofacial manifestations in patients with MPS frequently encountered by dentists may help recognize the disorder. However, because of sample size limitations, it was not possible to infer any statistical relationship between the radiographic features and the types of MPS.

Effect of Different Tube Potential Settings on Caries Detection using PSP Plate and Conventional Film.

PURPOSE: To compare intraoral Phosphor Stimulable Plate digital system and intraoral film using different tube settings on incipient proximal caries detection. MATERIALS AND METHODS: Five blocks, with five teeth each, were radiographically examined using phosphor plates and F-speed films. The images were acquired in 07 different tube potentials from 50-80 kV. The films were digitized. Three oral radiologists scored the images for the presence of caries using a 5-point rating scale. The areas under ROC curve were calculated. The influence of tube kilovoltage was verified by ANOVA and pair wise comparisons performed using Tukey test. RESULTS: Mean ROC curve areas varied from 0.446-0.628 for digital images and 0.494-0.559 for conventional images. The tube setting of 70 kV presented the best result both for digital and conventional images. Considering the image type separately, 70 kV scored highest followed by 75 and 65 kV for digital images (p=0.084). For conventional image modality, even though 70 kV presented the best result, it did not differ significantly from 80 kV, not differing from 60 and 55 kV, which did not differ from 75, 65 and 50 kV (p=0.53). CONCLUSION: Phosphor plate digital images seem to be more susceptible to tube setting potential variations then digitized film images.

The effect of two enhancement tools on the assessment of the relationship between third molars and the inferior alveolar canal.

OBJECTIVE: This study aims to assess the relationship between the inferior alveolar canal (IAC) and inferior third molars using digital panoramic images (DPI) with and without enhancement and compare the panoramic signs with cone beam computed tomography (CBCT) findings. METHODS: The DPIs and CBCT of 50 patients were analyzed. The DPIs were copied and enhanced using edge enhancement and an invert tool and then analyzed by two observers using the scores: darkening of the root; deflection of the root; narrowing of the root; superimposition of the root; bifurcation of the root over the IAC; diversion of the IAC; interruption of the cortex of the IAC, and no radiographic findings noted. Kappa and exact binominal tests were used to analyze the correlation between DPIs and CBCT images. The intimate relationship scores were evaluated using a t-test and Mann-Whitney test. RESULTS: The original DPIs, and the edge enhanced and invert tool images produced kappa coefficients of 0.528, 0.528 and 0.551, respectively. There was no difference among the methods evaluated in this study (p = 0.981). CONCLUSION: Similar agreement was observed between DPIs with and without enhancement. However, panoramic radiography is not the ideal method to analyze the relationship between lower third molars and the IAC.

Mesial inclination of impacted third molars and its propensity to stimulate external root resorption in second molars--a cone-beam computed tomographic evaluation.

PURPOSE: To investigate the presence of external root resorption (ERR) in second molars adjacent to horizontally and mesioangular impacted mandibular third molars by cone-beam computed tomography. In addition, patient characteristics (age and gender) and third molar depth were correlated with the presence of ERR. MATERIALS AND METHODS: The sample consisted of 116 scans (58 acquired on the i-CAT Classic and 58 on the Picasso-Trio) of 70 women and 46 men (mean age, 23.7 yr). Two observers recorded the presence of ERR in the second molars, inclination and depth of third molars in relation to bone and soft tissues, third molars classification according to Pell and Gregory, and location and severity of ERR. Data were analyzed by analysis of variance, Mann-Whitney test, and χ(2) test. The κ test was used to analyze intraobserver agreement. RESULTS: The overall prevalence of ERR was 49.43%. There were no statistically significant differences in the detection of ERR by gender, images from the 2 devices, or third molar inclination (P > .05). The κ test showed excellent reproducibility values (κ = 0.7778). There was a smaller proportion of affected patients 14 to 24 years old and ERR in teeth adjacent to Class C third molars. CONCLUSION: Mesially inclined third molars (mesioangular and horizontal) have a greater potential of being associated with ERR in second molars, which was shown by the high prevalence of the condition in the overall sample. Class A and B third molars in patients older than 24 years were more associated with the presence of ERR in adjacent teeth.

Fusão incomum de distomolar com terceiro molar avaliado por tomografia computadorizada de feixe cônico / Unusual fusion of a distomolar with a third molar assessed by cone-beam computed tomography

Os dentes supranumerários são uma anomalia e podem ser vistos em todos os quadrantes dos maxilares, com maior incidência na maxila. Quando os dentes supranumerários ocorrem distalmente ao terceiro molar, eles são denominados de dentes distomolares. Os distomolares ocorrem mais comumente unilateralmente na maxila de pessoas negras e afetam 2.2% da população. Por outro lado, a fusão ocorre pela união de dois germes dentários separados, desenvolvendo um único dente unido pela dentina e/ou pelo esmalte. A frequência de fusão de dentes permanentes e supranumerários é menor do que 0.1%, e normalmente envolve dentes anteriores da maxila. Radiografias periapicais são rotineiramente utilizadas em endodontia para o diagnóstico e planejamento pré-operatório, bem como durante o trans e pós-operatório. Entretanto, limitações relacionadas à bidimensionalidade dessa modalidade de imagens podem impedir a visualização adequada da anatomia dos canais radiculares dos dentes com variações anatômicas. O objetivo do presente relato foi descrever um caso raro de fusão por meio da tomografia computadorizada de feixe cônico...

Supernumerary teeth are teeth that occur in addition to the normal series. They can be observed in all quadrants of the jaw, with highest incidence in the maxilla. When a supernumerary tooth is distal to the most posterior molar, it is called a distomolar. Distomolars are more common unilaterally, in the maxilla and in black people and affect 2.2% of the population. In contrast, fusion is the result of the union of two separate tooth germs, forming a single tooth joined by dentin and/ or enamel, and fusion of a permanent tooth with a supernumerary accounts for fewer than 0.1% of cases, usually involving anterior maxillary teeth. Periapical radiographs are routinely used for endodontic diagnosis and preoperative planning, for transoperative guidance and for postoperative follow-up. However, the two-dimensional nature of this imaging technique can impose limitations on the ability to determine the anatomy of root canals in teeth with anatomical variations. The objective of this case report is to describe a rare case of fusion of a distomolar with a third molar, assessed using cone-beam computed tomography (CBCT)...

Digital radiographic evaluation of the midpalatal suture in patients submitted to rapid maxillary expansion.

AIMS: To analyze the density of the midpalatal suture by means of digital radiographs three months after retention to evaluate if this period of retention is really sufficient for bone repair. MATERIALS AND METHODS: This prospective study consisted of 31 patients (11 girls and 20 boys) in the mixed or permanent dentition stage, treated using a tooth-tissue borne expanders (Haas). Occlusal digital radiographs were taken at three stages: prior to rapid maxillary expansion (Stage I); immediately after desired maxillary expansion (Stage II); and after three months of retention (Stage III). Radiographs were taken on a dental X-ray machine, set at 70 kVp and 7 mA with an exposure time of 0.04 s. A phosphor storage plate system, imaging plate size n. 2 (35 × 45 × 1.6 mm), was used. Three regions (A, B and C) measured 0.02 mm² were selected for optical density analysis. The difference between the measurements was evaluated with the paired t-test. RESULTS: The optical density was reduced at Stages II and III compared with Stage I. Between-stage comparison showed statistically significant changes for all variables (P < 0.05), with the highest mean optical density at Stage I and the lowest at Stage II, in all groups. Actually, there was an increase in optical density between Stages II and III, but they are reduced compared with Stage I. CONCLUSION: The results strongly suggest that bone formation did not occur as expected, and that a longer retention period for bone repair may be necessary.

Detection of periimplant fenestration and dehiscence with the use of two scan modes and the smallest voxel sizes of a cone-beam computed tomography device.

OBJECTIVE: To assess the accuracy of cone-beam computed tomography (CBCT) in periimplant fenestration and dehiscence detection, and to determine the effects of 2 voxel sizes and scan modes. STUDY DESIGN: One hundred titanium implants were placed in bovine ribs in which periimplant fenestration and dehiscence were simulated. CBCT images were acquired with the use of 3 protocols of the i-CAT NG unit: A) 0.2 mm voxel size half-scan (180°); B) 0.2 mm voxel size full-scan (360°); and C) 0.12 mm voxel size full scan (360°). Receiver operating characteristic curves and diagnostic values were obtained. The Az values were compared with the use of analysis of variance. RESULTS: The Az value for dehiscence in protocol A was significantly lower than those of B or C (P < .01). They did not statistically differ for fenestration (P > .05). CONCLUSIONS: Protocol B yielded the highest values. The voxel sizes did not affect fenestration and dehiscence detection, and for dehiscence full-scan performed better than half-scan.

Usefulness of cone-beam CT in the evaluation of a spontaneously healed root fracture case.

Horizontal root fractures (HRF) usually affect anterior teeth of male patients as a result of trauma. The consequences can be complex because of combined damage to different tissues, but it has been reported that root fractures undergo healing in majority cases. Diagnosis of HRF must be based on clinical findings, sensibility tests, and radiographic examination. The cone-beam computed tomography (CBCT) has already been proven to be superior among other radiographic modalities for diagnostic imaging of root fractures. However, CBCT in these cases needs to be used in a careful manner, and only when the radiation exposure should be justified by the potential diagnostic benefits and improvement of the treatment results. This case report describes a case of spontaneously healed horizontal root fracture with displacement of the fragments and discusses the usefulness of CBCT in the follow-up of root fractures cases.

Diagnostic ability of a cone-beam computed tomography scan to assess longitudinal root fractures in prosthetically treated teeth.

INTRODUCTION: This study evaluated the influence of cast-gold posts on the diagnostic ability of a cone beam computed tomography (CBCT) system in assessing longitudinal root fractures. In addition, the influence of gutta-percha and variations in voxel resolution were assessed. METHODS: One hundred eighty endodontically prepared teeth were divided into 3 experimental and 3 control groups and placed in a dry human skull. The teeth in the experimental groups were artificially fractured. Certain experimental and control groups were filled with gutta-percha cones. Other experimental and control groups were filled with cast-gold posts. All the teeth were viewed by using a tomography scan with 2 voxel resolution protocols (0.3-mm and 0.2-mm). A calibrated examiner, blinded to the protocol, assessed the images by using the nominated scan software. RESULTS: The kappa values obtained for intraobserver reproducibility were 0.84 and 0.93 for 0.3-mm and 0.2-mm voxel resolution, respectively. The presence of gutta-percha or posts reduced the overall sensitivity and specificity in both voxel resolutions, but with no significant association. The CBCT specificity values were similar and did not depend on the voxel resolution adopted. In contrast, the sensitivity values were significantly higher for 0.2-mm voxel resolution in nonfilled (P < .05), gutta-percha (P < .001), and overall (P < .001) groups. CONCLUSIONS: The CBCT diagnostic ability was not influenced by the presence of posts or gutta-percha, and the 0.3-mm voxel resolution images were demonstrated not to be a reliable protocol for the investigation of longitudinal root fractures.

[Radioprotection in dentistry offices]. / Condições de radioproteção dos consultórios odontológicos.

In 1998, the Brazilian Ministry of Health established the Guidelines for Protection in Medical and Odontological Radiography, aimed at ensuring the quality of radiological procedures provided to the population as well as radiological protection for the health professionals. The purpose of this study was to verify the current situation in the dental offices with regard to the technical specifications and the adopted protective measures, using a questionnaire including questions about equipments, techniques and radiological protection. The investigated universe consisted of the surgeon dentists of the city of Aracaju using radiographic examination as a routine, resulting in a final sample of 103 professionals. The results showed that a high percentage of these professionals ignore the current norms (64.1%) as well as the technical specifications of their equipment (51.5% ignored the peak kilovoltage and 57.3% the milliamperage of their equipment), besides examining the radiographs visually (67%) As positive behaviors, the paralleling technique was preferred by 62.1% and the lead apron was used by 98.1%. We conclude that, despite the limited knowledge about the Guidelines, some measures are being correctly adopted but that the dentists have to be more aware of the necessary protective measures.

Comparative study of linear measurements performed in magnetic resonance and computed tomography images with the aid of an image realignment software / Estudo comparativo de medidas realizadas em imagens por ressonância magnética e por tomografia computadorizada com auxílio de um software de realinhamento de imagens

The aim of this study was to compare linear measurements of implant sites performed in magnetic resonance and computed tomography images with the aid of an image alignment software. Four patients from the Dental Implant Research and Teaching Center of Universidade Federal de Santa Catarina, Florianópolis, Brazil, were submitted to both computed tomography and magnetic resonance scans. An image realignment software was used to allow measuring the exact same sites on the images of both modalities. A total of eighty linear measuremensts of the posterior regions and twelve linear measurement of the anterior regions were performed with each modality. Measurements were carried out by one calibrated observer. Observer's reproducibility was higher than 97% (Dalberg's error). Student's t-test was used to compare the results of the height of the alveolar process in the computed tomography and magnetic resonance images. There was no statistically significant differences between the measurements performed in the computed tomography and magnetic resonance images (p = 0.4136). with a strong correlation between them (r = 0.8346). Similarly, there was no statistically significant differences between the measurements produced by the two modalities when the analysis discriminated the anterior and posterior regions (p = 0.7801 and p = 0.4381, respectively), with a strong correlation between the measurements in the posterior region of the jaws (r = 0.8547), and a weak correlation in the anterior region (r = 0.5472). Linear measurements of the alveolar process obtained from magnetic resonance and computed tomography images are comparable.

Condições de radioproteção dos consultórios odontológicos / Radioprotection in dentistry offices

Em 1998, o Ministério da Saúde estabeleceu as Diretrizes de Proteção Radiológica em Radiodiagnóstico Médico e Odontológico, visando garantir a qualidade nos procedimentos prestados à população e assegurar a proteção radiológica aos profissionais da saúde. O objetivo desta pesquisa foi verificar a situação dos consultórios odontológicos quanto às especificações técnicas preconizadas e às medidas de proteção adotadas, utilizando-se um questionário com itens sobre equipamentos, técnicas e proteção radiológica. O universo foi composto pelos cirurgiões-dentistas do município de Aracaju, Sergipe, que executam o exame radiográfico como rotina, sendo a amostra final de 103 profissionais. Dentre os resultados encontrados, destacam-se o alto índice de profissionais que desconhecem as normas atuais (64,1 por cento) e as especificações técnicas de seus equipamentos (51,5 por cento desconhecem a quilovoltagem e 57,3 por cento, a miliamperagem), como também aqueles que utilizam o método visual de revelação (67 por cento). Como condutas positivas, 62,1 por cento dos pesquisados fazem uso da técnica do paralelismo e 98,1 por cento utilizam a proteção plumbífera no paciente. Com isso, conclui-se que apesar de uma minoria conhecer as Diretrizes de Proteção, algumas medidas estão sendo corretamente adotadas; todavia, uma melhor conscientização se faz necessária.

In 1998, the Brazilian Ministry of Health established the Guidelines for Protection in Medical and Odontological Radiography, aimed at ensuring the quality of radiological procedures provided to the population as well as radiological protection for the health professionals. The purpose of this study was to verify the current situation in the dental offices with regard to the technical specifications and the adopted protective measures, using a questionnaire including questions about equipments, techniques and radiological protection. The investigated universe consisted of the surgeon dentists of the city of Aracaju using radiographic examination as a routine, resulting in a final sample of 103 professionals. The results showed that a high percentage of these professionals ignore the current norms (64,1 percent) as well as the technical specifications of their equipment (51,5 percent ignored the peak kilovoltage and 57,3 percent the milliamperage of their equipment), besides examining the radiographs visually (67 percent) As positive behaviors, the paralleling technique was preferred by 62,1 percent and the lead apron was used by 98,1 percent. We conclude that, despite the limited knowledge about the Guidelines, some measures are being correctly adopted but that the dentists have to be more aware of the necessary protective measures.