Radiomorphometric indices and fractal dimension of the mandible in individuals with osteogenesis imperfecta: a matched cross-sectional study.

OBJECTIVE: The objective was to analyze radiomorphometric indices (RMIs) of mandibular cortical bone and fractal dimension (FD) of trabecular bone of individuals with osteogenesis imperfecta (OI) and compare the findings to those of individuals without OI. METHODS: Digital panoramic radiographs of 20 individuals with OI (case group) and 40 individuals without OI (control group) were examined. The RMIs of mandibular cortical index (MCI) and mandibular cortical thickness (MCT) were analyzed. FD of mandibular trabecular bone was calculated bilaterally in 3 regions. The chi-squared test and paired t test were used to compare the significance of differences between the groups. The effect size and minimal clinically important difference (MCID) were also determined. Significance was established at P < .05. RESULTS: Categories C2 and C3 of the MCI were more frequent in individuals with OI (P < .001). The Mean MCT was 2.08 ± 0.79 in the OI case group and 2.91 ± 0.60 in the control group (P < .001). Mean FD in the condylar region was significantly lower in the OI case group (P = .002). The effect size for these 2 measures was large, and the difference between groups was greater than the MCID. CONCLUSION: Radiographs of individuals with OI exhibited more porosity and diminished thickness of the mandibular cortical bone and lower FD values in the condylar trabecular bone.

Radiological aspects of lymphomas and leukaemias affecting the jaws: A systematic review.

BACKGROUND: This systematic review aimed to investigate the radiological features of lymphomas and leukaemias affecting the jaws. METHODS: A systematic literature review was conducted using the electronic databases of PubMed, Web of Science and Scopus. Articles that contained sufficient radiographic examinations (periapical, panoramic or computed tomography images) for individual cases were included. Additionally, either immunohistochemical or molecular confirmation was required prior to inclusion. Three authors evaluated and described the image quality and radiological features. RESULTS: From an initial 1079 articles screened, 129 cases were included, containing 88 tomographic, 76 panoramic and 26 periapical examinations. The quality of the majority of images was sufficient for evaluation. Diffuse large B-cell lymphoma, Burkitt lymphoma, leukemic infiltration, plasmablastic lymphoma and extranodal Natural killer (NK)/T-cell lymphoma, nasal type were the most common subtypes. Involved teeth presented with mobility in 37.2% of the cases and a provisional diagnosis of inflammatory/infectious dental disease was considered in 49.2% of cases. Computed tomography exams were available for 76% of the cases, with most presented with an osteolytic lesion with ill-defined borders. Periosteal reactions were uncommon. CONCLUSION: Lymphoma/leukaemia infiltrates of the jaw bones are usually of high-grade subtypes and rarely present with periosteal reactions.

Indices in dental image exams for bone mineral density evaluation of aromatase inhibitor users.

We evaluated the accuracy of radiomorphometric indices (RI) and fractal dimension (FD) for screening bone mineral density (BMD) in postmenopausal patients who had breast cancer and were using aromatase inhibitors (AI). The sample consisted of 40 participants. Digital panoramic radiography (DPR) and cone beam computed tomography (CBCT) were evaluated along with dual-energy X-ray absorptiometry (DXA), which is the gold standard for detecting low BMD. According to the T-scores of DXA, the subjects were assigned into two groups: with normal BMD and with low BMD (osteopenia and osteoporosis). The area under the curve (AUC), sensitivity, and specificity with their respective confidence intervals were determined for DPR and CBCT. For DPR indices, AUC ranged from 52.6 to 75.8%. The mandibular cortical width (MCW) had the highest AUC. For FD, the total trabecular index had the highest sensitivity, while the index anterior to the mental foramen (MF) had the highest specificity. In CBCT, the AUC ranged from 51.8 to 62.0%. The indices with the highest AUC were the molar (M) and anterior (A). The symphysis (S) index had the highest sensitivity and the posterior (P) index had the highest specificity. Sensitivity and specificity were adequate for the computed tomography index (Inferior; CTI [I]). Therefore, MCW, FD of the mandible angle, and total trabecular ROI in DPR and the CTI (I), M, P, and A indices in CBCT proved to be promising tools in distinguishing individuals with low BMD. Cutoff point for these indices could be a useful tool to investigate low BMD in postmenopausal women taking AI.

Indices in dental image exams for bone mineral density evaluation of aromatase inhibitor users

Abstract We evaluated the accuracy of radiomorphometric indices (RI) and fractal dimension (FD) for screening bone mineral density (BMD) in postmenopausal patients who had breast cancer and were using aromatase inhibitors (AI). The sample consisted of 40 participants. Digital panoramic radiography (DPR) and cone beam computed tomography (CBCT) were evaluated along with dual-energy X-ray absorptiometry (DXA), which is the gold standard for detecting low BMD. According to the T-scores of DXA, the subjects were assigned into two groups: with normal BMD and with low BMD (osteopenia and osteoporosis). The area under the curve (AUC), sensitivity, and specificity with their respective confidence intervals were determined for DPR and CBCT. For DPR indices, AUC ranged from 52.6 to 75.8%. The mandibular cortical width (MCW) had the highest AUC. For FD, the total trabecular index had the highest sensitivity, while the index anterior to the mental foramen (MF) had the highest specificity. In CBCT, the AUC ranged from 51.8 to 62.0%. The indices with the highest AUC were the molar (M) and anterior (A). The symphysis (S) index had the highest sensitivity and the posterior (P) index had the highest specificity. Sensitivity and specificity were adequate for the computed tomography index (Inferior; CTI [I]). Therefore, MCW, FD of the mandible angle, and total trabecular ROI in DPR and the CTI (I), M, P, and A indices in CBCT proved to be promising tools in distinguishing individuals with low BMD. Cutoff point for these indices could be a useful tool to investigate low BMD in postmenopausal women taking AI.

Anatomical evaluation of the medial lingual foramen using cone-beam computed tomography: a retrospective study / Avaliação anatômica do forame lingual medial usando tomografia computadorizada de feixe cônico: um estudo retrospectivo

ABSTRACT Objective: To evaluate the frequency of medial lingual foramina present in the cortex of the mandible using cone beam computed tomography (CBCT). Methods: A total of 953 CBTC exams of the mandible were evaluated to determine the presence of canals in the mandibular midline, canal location in relation to the mental spine, canal diameter, distance to the base and alveolar crest of the mandible, trajectory of the canal, and coincidence measurements of the panoramic image containing the location of the canal in relation to the mental spine. Results: Foramina were located in three positions: above the mental spine (FSS) 89.2%, below the mental spine (FIS) 67.9%, and other positions (FOP) 21.3%. Non-edentulous individuals had a significantly higher number of FSS than did edentulous individuals (P<0.001). Male individuals presented a significantly greater distance from the FSS (P=0.001), FIS (P=0.045) and FOP (p=0.002) to the base of the mandible than female individuals. Younger individuals presented a significantly higher distance from the FSS (P=0.001) and FIS (P=0.001) to the alveolar crest of the mandible. Male individuals had a significantly greater FIS (P=0.002) and FOP (P=0.001) diameter than female individuals. Male individuals had a significantly higher number of bifurcations in FOP than female individuals (P=0.017). Conclusion: CBCT supplies the provider with a detailed assessment of the foramina and canals, which improves the quality of surgical planning and mitigates the chances of surgical intercurrences.

RESUMO Objetivo: Avaliar a frequência dos forames linguais mediais presentes na cortical da mandíbula por meio da tomografia computadorizada de feixe cônico (TCFC). Métodos: Um total de 953 exames de TCFC da mandíbula foram avaliados para determinar a presença de canais na linha média mandibular, localização do canal em relação ao tubérculo geniano, diâmetro do canal, distância à base e crista alveolar da mandíbula, trajetória da canal e medidas de coincidência da imagem panorâmica contendo a localização do canal em relação ao tubérculo geniano. Resultados: Os forames localizaram-se em três posições: acima do tubérculo (FSS) 89,2%, abaixo do tubérculo (FIS) 67,9% e outras posições (FOP) 21,3%. Indivíduos não edêntulos apresentaram um número significativamente maior de FSS do que indivíduos edêntulos (P <0,001). Indivíduos do sexo masculino apresentaram distâncias significativamente maior do FSS (P = 0,001), FIS (P = 0,045) e FOP (p = 0,002) até a base da mandíbula do que indivíduos do sexo feminino. Os indivíduos mais jovens apresentaram uma distância significativamente maior do FSS (P = 0,001) e FIS (P = 0,001) até a crista alveolar da mandíbula. Indivíduos do sexo masculino tiveram um diâmetro de FIS (P = 0,002) e FOP (P = 0,001) significativamente maior do que indivíduos do sexo feminino. Indivíduos do sexo masculino tiveram um número significativamente maior de bifurcações no FOP do que indivíduos do sexo feminino (P = 0,017). Conclusão: a TCFC fornece ao profissional uma avaliação detalhada dos forames e canais, o que melhora a qualidade do planejamento cirúrgico e diminui as chances de intercorrências.

Evaluation of temporal bone pneumatization using panoramic radiography and cone beam computed tomography / Avaliação da pneumatização do osso temporal por meio de radiografia panorâmica e tomografia computadorizada de feixe cônico

Aim: To evaluate the presence and characteristics of pneumatizations in the roof of the mandibular fossa and articular eminence by panoramic radiography and cone beam computed tomography (CBCT).Methods: This study analyzed CBCT images of the temporomandibular joint of 705 patients, In 60 exams, it was possible to compare tomographic with panoramic images. For cases where pneumatization was present, laterality and pattern of manifestation were considered. A chi-square test was used to compare the differences between CBCT and panoramic radiography in the diagnosis of pneumatization. Results: Descriptive analysis revealed a sample profile that was predominantly female (75.9%), with a mean age of 42.6 years (± 17.4). The presence of pneumatizations in the roof of the mandibular fossa and articular eminence in CBCT images was identified in 330 (46.8%) and 154 (21.8%) exams, respectively, and the most frequent pneumatization pattern was the multilocular type in both locations. Bilateral pneumatization was more prevalent in the roof of the mandibular fossa. Considering the analysis of 60 pairs of exams, in panoramic radiography, pneumatizations in the roof of the mandibular fossa and articular eminence were identified in 22 (36.7%) and 12 (20.0%) examinations, respectively. Regarding CBCT images, pneumatizations in the roof of the mandibular fossa was observed in 24 (40.0%) exams, while articular eminence was found in 14 (23.3%) images. There were no statistically significant differences between the proportion of pneumatization identified by panoramic radiography and CBCT (p > 0.05). Conclusion: This study suggests that panoramic radiography may be an imaging method used to evaluate pneumatization in the temporomandibular joint region.

Objetivos: Avaliar a presença e as características da pneumatização no teto da fossa mandibular e eminência articular por meio de radiografias panorâmicas (RP) e tomografias computadorizadas de feixe cônico (TCFC). Métodos: Foram analisadas imagens tomográficas da ATM de 705 pacientes, sendo que 60 desses pacientes também possuíam RP. Para todos os casos foram avaliadas a presença, a lateralidade e o padrão de manifestação da pneumatização. O teste qui-quadrado foi empregado para comparar os resultados obtidos a partir das RP e das TCFC no que tange o diagnóstico das pneumatizações. Resultados: A análise descritiva revelou uma amostra predominantemente feminina (75,9%) com uma média de idade de 42,6 anos (± 17,4). A pneumatização no teto da fossa mandibular e eminência articular foi evidenciada em 330 (46,8%) e 154 (21,8%) imagens de TCFC, respectivamente, e o padrão de pneumatização mais frequente foi o multilocular em ambas as regiões. A pneumatização bilateral foi mais prevalente no teto da fossa mandibular. Considerando a análise dos 60 pares de exames, nas radiografias panorâmicas as pneumatizações no teto da fossa mandibular e eminência articular foram identificadas em 22 (36,7%) e 12 (20,0%) exames, respectivamente. Em relação às imagens tomográficas, a presença desse achado no teto da fossa foi observada em 24 (40,0%) exames e na eminência articular em 14 (23,3%). Não houve diferença com significância estatística entre a proporção de pneumatização identificada em RP e TCFC (p > 0,05). Conclusão: Os resultados obtidos sugerem que a radiografia panorâmica pode ser um método de diagnóstico por imagem empregado para avaliação de pneumatizações na região da ATM.

New mandibular indices in cone beam computed tomography to identify low bone mineral density in postmenopausal women.

OBJECTIVE: The aim of this study was to evaluate new radiomorphometric indices in cone beam computed tomography (CBCT) for assessing bone mineral density (BMD) status in postmenopausal women. STUDY DESIGN: Mandibular inferior cortical bone thickness was evaluated in 48 postmenopausal women in cross-sectional images at 4 sites: (1) symphysis (S): cross-sectional image equidistant from the centers of the right and left mental foramina (MF); (2) anterior (A): 10 mm anterior to the MF; (3) molar (M): 10 mm posterior to the MF; and (4) posterior (P): 25 mm posterior to the MF. Participants underwent dual-energy x-ray absorptiometry and were divided into normal, osteopenia, and osteoporosis groups. In the study, t tests with Bonferroni correction were conducted. Statistical significance was set at P < .017. Receiver operator characteristic (ROC) analyses were performed. RESULTS: Mean S index was significantly lower in osteoporosis than in osteopenia (P = .005). Mean M index was significantly lower in osteopenia (P < .001) and osteoporosis (P = .001) than in normal individuals. Mean P index was significantly lower in osteoporosis than in normal patients (P = .008). ROC values ranged between 0.643 and 0.740. Cortical thicknesses separating normal from abnormal varied from 1.73 mm to 3.37 mm. CONCLUSIONS: M and P indices in CBCT may be useful for identifying low BMD in postmenopausal women.

Imaging diagnosis of external root resorption in replanted permanent teeth.

The present study aimed to evaluate the performance of cone beam computed tomography (CBCT) and digital periapical radiographs (PR) in diagnosing external root resorption (ERR) in human permanent teeth replanted after traumatic avulsion. The samples comprised 39 permanent maxillary incisors replanted after traumatic avulsion. Digital PR and CBCT images were taken from each tooth and independently examined by 2 calibrated examiners to assess the ERR activity regarding type and extension. The degrees of agreement between both imaging examinations were determined by the mean global agreement index using SPSS software. The two imaging examinations diverged greatly in the diagnosis of the type of ERR since CBCT identified more cases as inflammatory ERR and PR as replacement ERR. A discordance level of 69.2% was observed between the two methods in the diagnosis of the type of ERR when CBCT for mesial and distal (MD) surfaces was considered and 61.5% when CBCT for mesial, distal, buccal and lingual (MD/BL) was considered. Likewise, CBCT and PR differed regarding the ERR index. PR examinations classified most cases as moderate or severe (69.2%), while CBCT examinations classified more cases as mild either in the MD surfaces analysis (41.4%) or in the analysis of the MD-BL surfaces (51.3%). In conclusion, the present results highlight a discrepancy between CBCT and digital PR performance in the diagnosis of different types and extent of ERR in replanted teeth.

Coronectomy of partially erupted lower third molars performed by an undergraduate dentistry student: a case series.

PURPOSE: The coronectomy technique is an alternative to conventional impacted tooth removal which aims to reduce the risk of damage to the inferior alveolar nerve (IAN). The technique is usually performed by senior oral surgeons or residents in training. Herein, patients were treated in a single service, in which coronectomy was performed by an undergraduate dental student on partially erupted lower third molars. METHODS: A prospective analysis was performed on 21 individuals submitted to a total of 35 coronectomies. Clinical and radiographic follow-up was performed for at least 12 months. RESULTS: Overall, healing was within normal limits, without major complications and without permanent IAN injury. However, one case showed temporary IAN paraesthesia resolved within a month and two required repetitions of coronectomy due to the remaining enamel, but with a good final result. Root migration was observed in all cases, but no other surgery was required. CONCLUSION: Coronectomy may be an important option for treating partially erupted teeth in close nerve relationships, which could also be performed by trained undergraduate dental students. This series is interesting because it can encourage oral and maxillofacial surgeons to train undergraduate students and to stimulate their attraction and passion for surgery.

Cone-beam computed tomography analysis of cemento-osseous dysplasia-induced changes in adjacent structures in a Brazilian population.

OBJECTIVES: To describe the effects of cemento-osseous dysplasia (COD) on anatomical structures. METHODS: CBCT scans were retrospectively selected from a database of individuals who attended an Oral Medicine service. Cases with a confirmed diagnosis of periapical, focal, or florid COD were included. Two oral and maxillofacial radiologists assessed the scans. Frequencies of the variables were described according to COD case, lesion areas, and teeth. RESULTS: Sixty COD cases affected 244 areas and 426 teeth. Florid COD was the most common (n = 48). Cortical bone (buccal, lingual, palatine, or mandibular) (n = 42) and the maxillary sinus (n = 13) were the structures most frequently affected by displacement or perforation. Thinning (n = 80), expansion (n = 62), and perforation (n = 60) of the cortical bone were common effects. The median size of the lesions was 12 mm in the mesiodistal direction, 8 mm in the buccal-lingual/palatal direction, and 9 mm in the superior-inferior direction. Root resorption was observed in 18.1% of all teeth, while tooth displacement was uncommon (0.6%). All teeth affected by COD had a discontinuous lamina dura and non-uniformly visible periodontal ligament space. CONCLUSIONS: CBCT images revealed that cortical bone, lamina dura, and periodontal ligament space were the structures most affected by COD and the effects of COD on anatomical structures were more frequent than previously described. CLINICAL RELEVANCE: CODs are fibro-osseous lesions common in the clinical practice, and relationship with anatomical structures is poorly described. CBCT is an appropriate method for the diagnosis and follow-up of patients with COD.

Doxycycline encapsulated in ß-cyclodextrin for periodontitis: a clinical trial.

This clinical trial compared the efficacy of doxycycline (DOX) in ß-cyclodextrin (DOX)/ßCD) with DOX- alone in gel on thirty-three subjects with periodontitis. Patients were randomized to group 1 GI; 10% DOX + scaling and root planning (SRP); group 2 (GII (10% DOX /ß-CD + SRP), and group 3 (GIII; SRP). Gels were applied in GI and GII at baseline (T0) and 30 days later (T1). Periodontal Probing Depth (PPD), Clinical Attachment Level (CAL), Bleeding on Probing (BOP) and Visible Plaque Index (VPI) were evaluated at (T0), 30 days (T1) and 60 days after T0 (T2). Bone density was analyzed after 18 months (T3). GII showed the most significant reduction of PPD (2.62 mm; p <0.003), and greatest gain in CAL (2.54 mm p <0.003) at T2. BOP and the VPI had a strong reduction in all groups at T2 (p <0.05), both decreased by ≥5 times and 2 times, respectively, in all groups at T1. Bone density increased in all groups in radiographs (T3). The use of DOX encapsulated in ß-CD gel with SRP resulted in significant improvements in clinical periodontal parameters; such molecular inclusion of doxycycline into ß-CD in gel for local application is relatively simple and useful in dentistry.

Imaging diagnosis of external root resorption in replanted permanent teeth

Abstract The present study aimed to evaluate the performance of cone beam computed tomography (CBCT) and digital periapical radiographs (PR) in diagnosing external root resorption (ERR) in human permanent teeth replanted after traumatic avulsion. The samples comprised 39 permanent maxillary incisors replanted after traumatic avulsion. Digital PR and CBCT images were taken from each tooth and independently examined by 2 calibrated examiners to assess the ERR activity regarding type and extension. The degrees of agreement between both imaging examinations were determined by the mean global agreement index using SPSS software. The two imaging examinations diverged greatly in the diagnosis of the type of ERR since CBCT identified more cases as inflammatory ERR and PR as replacement ERR. A discordance level of 69.2% was observed between the two methods in the diagnosis of the type of ERR when CBCT for mesial and distal (MD) surfaces was considered and 61.5% when CBCT for mesial, distal, buccal and lingual (MD/BL) was considered. Likewise, CBCT and PR differed regarding the ERR index. PR examinations classified most cases as moderate or severe (69.2%), while CBCT examinations classified more cases as mild either in the MD surfaces analysis (41.4%) or in the analysis of the MD-BL surfaces (51.3%). In conclusion, the present results highlight a discrepancy between CBCT and digital PR performance in the diagnosis of different types and extent of ERR in replanted teeth.

Comparison between fractal analysis and radiopacity evaluation as a tool for studying repair of an osseous defect in an animal model using biomaterials.

OBJECTIVES: To evaluate bone repair of an osseous defect in a rat animal model through fractal analysis and radiopacity analysis in radiographic images. METHODS: 120 rats were subjected to extraction of their first molar and divided into four groups (n = 6/group) according to the material used for bone grafting: mineralized bovine bone, demineralized bovine bone (DBB), blood clot (BC - control) or Bio-Oss® (BO). The animals were sacrificed after 1, 7, 14, 21 and 49 days and subjected to radiographic evaluation. For fractal analysis (FA), a square regionof interest of 30 × 30 pixels was used, and radiopacity was measured as the mean gray scale (MGS) value for three points of 5 × 5 pixels in the apical, medial and coronal regions of the defect. Histomorphometric evaluation was realized as the gold standard for bone neo-formation and maturation of the new osseous matrix. RESULTS: Histomorphometric evaluation suggested that DBB showed faster mineralized deposition and resulted in more mature bone at the final time point of evaluation. Mineralized bovine bone and Bio-Oss presented similar results. The mineralized groups did not show significant differences in bone maturation. The radiopacity analysis revealed a significant difference (p < 0.05) between the DBB and blood clot groups at the final time point. FA did not show any significant differences at the final time point. CONCLUSIONS: Mean gray scale seemed to be more effective for the quantification of bone repair than FA in the demineralized group in this animal model. Results for the mineralized groups did not reveal a significant difference, leading to the conclusion that both methods are effective.

Mandibular buccal bifurcation cyst: Case report and literature review.

The present study reports a case of a mandibular buccal bifurcation cyst (MBBC) associated with a partially erupted mandibular first molar. The intraoral examination revealed vestibular swelling in the right mandibular permanent first molar region. Panoramic radiography and cone-beam computed tomography (CBCT) showed a well-delimited radiolucent image involving the roots and part of the crown of the right mandibular permanent first molar with bulging and areas of buccal cortical bone resorption. An incisional biopsy was performed and the diagnosis was MBBC. The lesion was surgically removed by enucleation and curettage. Bone repair was observed seven months after the surgical procedure.

Comparative study of oral and salivary parameters in patients with and without loss of bone mass.

Osteoporosis is an insidious and increasingly prevalent disease that can cause fractures and affect patients' quality of life. The current study comparatively evaluates patients with and without loss of bone mass in terms of salivary calcium, viscosity, and pH. A controlled cross-sectional study was conducted in two groups of 32 postmenopausal women subjected to a bone densitometry scan and later referred for dental management at the Federal University of Minas Gerais, Brazil. The patients were assigned to two groups: Group 1 - patients with low bone mineral density (BMD) and Group 2 - patients without bone mineral changes. The following salivary parameters were evaluated: calcium concentration, flow rate, viscosity, pH, and average total protein. An oral examination was performed for assessment of DMFT variables and tongue coating. Data were analyzed using descriptive and inferential statistics, adopting a p-value < 0.05. The patients' mean age was 60 years (± 7.35). Salivary flow, pH, and viscosity were similar among the groups. Average total protein was 14.8 mg/mL and 19.0 mg/mL in Groups 1 and 2, respectively. Tongue coating and salivary calcium levels were significantly higher in Group 1 (p < 0.001). Salivary calcium is an important screening tool and may eventually be used for the diagnosis of bone mineral changes.

Extending Coronectomy Indications to Third Molars with Taurodontism to Prevent Paresthesia and Mandible Fracture.

Taurodontism is considered a dental anomaly responsible for a morphoanatomical change in the shape of the tooth in which the roots are reduced in size but the body of the tooth is enlarged and bulky. The aim of this paper is to present a case of a 25-year-old female patient with taurodontism of mandibular partially erupted third molars, presenting a high risk of angle fracture and paresthesia in case of their removal, treated by means of coronectomy. The postoperative period was uneventful and the patient remained in follow-up for 12 months. In conclusion, the identification of third molars with higher risk of complications related to their extractions is the key to consider conservative measures to avoid problems. Coronectomy is a relatively simple technique that should be taken into account when considering bulky, deeply located third molars with a high risk of paresthesia or mandibular fracture, even in presence of taurodontism.

Comparative study of oral and salivary parameters in patients with and without loss of bone mass

Abstract Osteoporosis is an insidious and increasingly prevalent disease that can cause fractures and affect patients' quality of life. The current study comparatively evaluates patients with and without loss of bone mass in terms of salivary calcium, viscosity, and pH. A controlled cross-sectional study was conducted in two groups of 32 postmenopausal women subjected to a bone densitometry scan and later referred for dental management at the Federal University of Minas Gerais, Brazil. The patients were assigned to two groups: Group 1 - patients with low bone mineral density (BMD) and Group 2 - patients without bone mineral changes. The following salivary parameters were evaluated: calcium concentration, flow rate, viscosity, pH, and average total protein. An oral examination was performed for assessment of DMFT variables and tongue coating. Data were analyzed using descriptive and inferential statistics, adopting a p-value < 0.05. The patients' mean age was 60 years (± 7.35). Salivary flow, pH, and viscosity were similar among the groups. Average total protein was 14.8 mg/mL and 19.0 mg/mL in Groups 1 and 2, respectively. Tongue coating and salivary calcium levels were significantly higher in Group 1 (p < 0.001). Salivary calcium is an important screening tool and may eventually be used for the diagnosis of bone mineral changes.

Estudo da frequência e da variabilidade de posições dos terceiros molares nas radiografias panorâmicas no serviço de radiologia da Faculdade de Odontologia da Universidade Federal de Minas Gerais / The study of frequency and variability of third molars positions in panoramic radiographs at the radiology service of the School of Dentistry of the Federal University of Minas Gerais

Objetivo: Traçar um perfil epidemiológico da variação de posição dos terceiros molares dos pacientes que frequentaram o serviço de radiologia da Faculdade de Odontologia da Universidade Federal de Minas Gerais (FO-UFMG) no período de setembro de 2014 a setembro de 2015, visando melhorar o conhecimento do cirurgião dentista para planejamentos cirúrgicos mais assertivos. Métodos: Foram analisadas 469 radiografias panorâmicas que possuíam pelo menos um terceiro molar. Essas radiografias foram classificadas de acordo com a posição do terceiro molar em relação ao plano oclusal; ao eixo do segundo molar; ao ramo ascendente da mandíbula e ao canal mandibular. Resultados: Dentre as 469 radiografias analisadas, 62,7% foram de pacientes do gênero feminino e 37,3% do gênero masculino. Foi possível observar a presença dos dentes 18 (370); 28 (369); 38 (341) e 48 (363); o que resultou em 1.443 terceiros molares presentes no estudo. A maioria dos terceiros molares inferiores encontrava-se na posição vertical, seguida pelas posições mesioangular e horizontal. A classe II foi a mais frequente, seguida pela classe I e por último da classe III e maioria dos terceiros molares inferiores estava na posição A seguidos pela posição B e por último da posição C. O sinal radiográfico mais frequente foi o obscurecimento dos ápices. Conclusão: Foi possível observar a frequência das posições dos terceiros molares inferiores através da análise das radiografias panorâmicas realizadas no serviço de radiologia da Faculdade de Odontologia da UFMG. O conhecimento das posições e classificações dos terceiros molares nas radiografias panorâmicas pelo cirurgião dentista pode contribuir para um diagnóstico e planejamento cirúrgico adequados. Descritores: Dente terceiro molar. Radiografia panorâmica. Radiologia.(AU)

Aim: This article seeks to describe the epidemiological profile of the variation and frequency of the positioning of third molars of patients who received dental care at the Radiology Department of the School of Dentistry of the Federal University of Minas Gerais (UFMG) from September 2014 to September 2015. The overall aim is to improve the knowledge of dental surgeons for better surgical planning. Methods: This study selected 469 radiographs that had at least one third molar. These radiographs were classified according to the position of the third molars in relation to the occlusal plane, to the axis of the second molar, to the ascending mandibular ramus, and to the mandibular canal. Results: Among the 469 radiographs analyzed in this study, 62.7% were female patients and 37.3% were male. It was possible to observe the presence of teeth 18 (370), 28 (369), 38 (341), and 48 (363), which resulted in study sample of 1,443 third molars. Most of the mandibular third molars were found in the vertical position, followed by the mesioangular position and the horizontal position. Class II was the most frequent, followed by class I and class III. Moreover, most of the mandibular third molars were found in position A, followed by position B and position C. The most commonly observed radiographic sign was the obscuration of the roots. Conclusion: It was possible to observe the frequency of positions of the mandibular third molars through the analysis of panoramic radiographs performed at the radiology service of the Radiology Department of the UFMG School of Dentistry. The dental surgeon's knowledge of the positions and classifications of third molars in panoramic radiographs can aid in reaching an appropriate diagnosis and proper surgical planning.(AU)

Avaliação dos níveis de cinza de cimentos ionômero de vidro em imagens digitais indiretas / Evaluation of the gray-scale values of glass ionomer cement in indirect digital imaging

Objetivo: Comparar a radiopacidade de quatro marcas comerciais de cimentos ionômero de vidro por meio da mensuração dos níveis de cinza em imagens digitais indiretas. Materiais e Métodos: Foram confeccionados cinco corpos de prova nas espessuras de 1, 2, 3 e 4mm dos seguintes materiais: Magic Glass® R, Maxxion® R, Vidrion® R e Chemflex®. As amostras foram separadas por marca e espessura e radiografadas seguindo uma técnica padronizada. Foram realizadas três radiografias por espessura para cada material avaliado. As imagens obtidas foram posteriormente digitalizadas e analisadas por meio da ferramenta histograma do software Adobe Photoshop 8.0 para a determinação dos níveis de cinza. Para isso, foram realizadas três leituras em áreas diferentes de cada uma das amostras confeccionadas para cada espessura das marcas comerciais avaliadas. Os valores obtidos foram posteriormente submetidos a uma média aritmética e os resultados expressos como média dos níveis de cinza por espessura para cada material. Os dados foram analisados por meio da análise de variância ANOVA (p<0,05) e comparação múltipla de Bonferroni (p<0,05). Resultados: Para todos os cimentos avaliados as espessuras apresentaram diferenças estatisticamente significativas quando comparadas entre si para o mesmo material (p<0,001). Os valores dos níveis de cinza aumentaram conformea espessura dos corpos de prova. As médias dos valores de níveis de cinza encontradas em cada um dos cimentos avaliados, para uma mesma espessura foram diferentes e os resultados estatisticamente significativos p<0,001). Conclusão: Os cimentos ionômeros de vidro apresentaram variações quanto à radiopacidade, sendo que a espessura dos corpos de prova contribuiu para tal propriedade. O Chemflex® apresentou o maior valor médio de níveis de cinza, sendo o material de maior radiopacidade dentre todos os avaliados.

Estimativa de dose efetiva e detrimento em exames de tomografia computadorizada de feixe cônico (TCFC) / Effective dose and detriment assessment in cone beam computed tomography (CBCT)

Objetivo: Estimar a dose efetiva (E) e o detrimento associados aos exames de Tomografia Computadorizada de Feixe Cônico (TCFC), seguindo as últimas recomendações da International Comission on Radiological Protection (ICRP). Materiais e Métodos: A E foi calculada multiplicando-se as dosesabsorvidas/equivalentes pela medula óssea, tireóide, pele, superfície óssea, glândulas salivares, cérebro e órgãos remanescentes (região extra-torácica, linfonodos, músculo e mucosa oral), resultantes de diferentes equipamentos e protocolos de aquisição de imagens, pelo fator de peso desses tecidos. O detrimento foi estimado multiplicando-se o valor de E pelo coeficiente de probabilidade de efeitos estocásticos resultantes de baixas doses de radiação que é 5,7 x 10-2 eventos por Sievert (Sv). Os equipamentos e protocolos foram agrupados de acordo com o volume irradiado (campo de visão). A média, desvio padrão e coeficiente devariação de cada grupo foram calculados. Resultados: Protocolos que empregaram um campo de visãomaior resultaram em aumento da dose efetiva e do detrimento. As médias (desvio-padrão) das doses efetivaspara campos de visão pequeno, médio e grande foram 33,91 μSv (13,38), 82,85 μSv (74,26) e 107,99 μSv (43,82), respectivamente. O grupo de campo de visão pequeno apresentou menor coeficiente de variação (39%). Conclusão: A E resultante da TCFC é alta comparada a outros exames radiográficos convencionais,embora o detrimento seja relativamente pequeno. A indicação dos exames e a seleção dos protocolos devem ser criteriosamente justificadas de forma que os benefícios resultantes da exposição dos pacientes à radiaçãosuperem o potencial detrimento.