Overweight/obesity and dental caries in Brazilian children and adolescents: a systematic review and meta-analysis

This review aimed to assess the association between overweight/obesity and dental caries in Brazilian children/adolescents. Searches were performed in the Web of Science, Scopus, Cochrane, PubMed, Embase and SciELO, Lilacs and Open Grey literature databases up to June 2022. The Joanna Briggs Institute checklist for analytical cross-sectional studies, the checklist for cohort studies, and the checklist for case-control studies were used. A total of 41 publications were included, and 15 meta-analyses were performed. The authors analyzed the differences in weighted mean difference (MD) and odds ratios (OR), and their corresponding confidence intervals (CI) (95%) for dental caries among eutrophic and obese and/or overweight children/adolescents. Meta-analyses showed that there was no association between overweight and/or obesity and dental caries in Brazilian children/adolescents for most anthropometric reference curves using BMI (Body Mass Index). A greater experience of dental caries was associated with well-nourished adolescents in permanent dentition, compared with obese individuals in the same dentition, as classified by the CDC 2000 curve (OR = 2.53, 95% CI;1.49-4.29; p = 0.0006; I2 = 0%) in dichotomous outcome studies, and (MD = 0.61, 95%CI: 0.08-1.15; p = 0.02; I2 = 0%) in continuous studies. The strength of the evidence of the results was classified as very low, low or moderate. It was concluded that there is no association between overweight and/or obesity and dental caries in Brazilian children/adolescents for most anthropometric reference curves using BMI. A greater experience of dental caries was associated with well-nourished adolescents in permanent dentition, compared with obese individuals in the same dentition, as classified by the CDC 2000 curve.

Microtensile Bond Strength of Self-Etch Adhesives on Dentin Treated with Chlorhexidine

AIM

To evaluate the microtensile bond strength of self-etching adhesive systems in dentin treated with 2% chlorhexidine digluconate (CHX).

MATERIALS AND METHODS

The occlusal surfaces of 20 human molars were removed and divided into eight groups: 1A, Clearfil SE adhesive (SE) with self-etching technique (TS); 1B, SE with TS and previous application of CHX; 2A, Scotchbond Universal (SBU) adhesive with TS; 2B, SBU adhesive with TS and previous application of CHX; 1C, SE with total-etching technique (TT); 1D, SE with TT and previous application of CHX; 2C, SBU with TT; 2D SBU with TT and previous application of CHX. Composite resin (5mm) was applied on the hybridized surface. Samples were subjected to microtensile test and evaluated on Scanning Electron Microscope (SEM) and with energy-dispersive X-ray (EDX).

RESULTS

Low values of bond strength were observed in groups 1A (39,77±11,56) and 2A (40,84±12,49) comparing with 1B (22,86±5,18) and 2B (27,02±5,58). TS group presented adhesive type remover fracture while TT groups presented cohesive at the top of hybrid layer. EDX revealed the presence of CHX crystals for TS, which was not found in the TT.

CONCLUSION

The previous application of chlorhexidine on dentin decreased the bond strength of adhesive systems on self-etching technique.

Fractal analysis of the mandible cortical bone: correlation among fractal dimension values obtained by two processing methods from periapical radiograph and micro-computed tomography with cone-beam computed tomography

The objectives of the present study were to assess Fractal Dimension (FD) values in the mandible cortical bone obtained from digital periapical radiographs (DPR), high-resolution microtomography (µCT), and cone-beam computed tomography (CBCT), by two processing methods: binarization (FD.b) and grayscale-based method (FD.f) and, finally, to identify the correlation among these values with other micro-architectural parameters. For this, a prospective study was conducted on 18 healthy individuals (mean age 23 ± 2.4 years old) who underwent third molar extraction. Pre-operative CBCT scans were conducted, bone fragments were removed from the retro-molar region, and DPR and µCT were performed on those bone samples. FD.b and FD.f values were calculated using three parasagittal sections for CBCT, one image for DPR, and three sections for µCT. The 3D bone microarchitecture was analyzed in µCT (voxel size: 19 µm). As a result, FD.b mean values of 1.55 ± 0.02 and 1.80 ± 0.01 were obtained for CBCT and µCT, respectively. Furthermore, FD.f mean values of 1.22 ± 0.12 for DPR, 0.99 ± 0.04 for CBCT, and 1.30 ± 0.07 for µCT were obtained. Both FD.b and FD.f values showed a good agreement. FD.f was negatively correlated with the standard deviation of the mean gray value (p = 0.003) for DPR and intra-cortical bone surface (p = 0.02) for µCT. In conclusion, image processing with or without binarization revealed different values for FD, although showing agreement. The grayscale-based method retrieved FD values correlated with the gray levels and the cortical porous network, which means that FD can be a valuable index for mandibular cortical bone evaluation. FD is associated with mineralization and microarchitecture. Nevertheless, there was no correlation between FD values obtained from low- (DPR) and high-resolution (µCT) X-ray modalities with FD obtained from the in vivo CBCT.

Fractal dimension, lacunarity, and cortical thickness in the mandible: Analyzing differences between healthy men and women with cone-beam computed tomography

Purpose

The objective of this study was to assess the fractal dimension, lacunarity, trabecular microarchitecture parameters, and cortical linear measurements in the mandibles of male and female individuals to identify differences between them.

Materials and Methods

In total, 116 cone-beam computed tomography scans of healthy individuals of different ages (57 men and 59 women, aged between 20 and 60 years) were selected. The following bone parameters were measured: 1) buccal, lingual, and basal cortical bone thickness in 5 standard parasagittal sections (the midline, the left and right sides of the lower lateral incisors, and the left and right sides of the lower canines); 2) the bone volume fraction of 10 sequential axial sections from each patient by creating a volume of interest in the area between the lower canines; and 3) fractal dimension and lacunarity using grayscale images of the same region of the volume of interest in the anterior mandible. Spearman correlation coefficients and the Mann-Whitney test were used.

Results

A significant and positive correlation was found between age and cortical thickness, especially in the region of the central incisors. Significant differences between sexes in terms of fractal dimension, lacunarity, and bone volume were found. Women revealed lower fractal dimension values and higher lacunarity and bone volume ratio values than men.

Conclusion

Fractal dimension, lacunarity, trabecular bone volume, and cortical thickness were different between men and women of different ages.

MRI changes and clinical characteristics in temporomandibular joints with displacement of the articular disk without reduction - a cross-sectional observational study

OBJECTIVES

This study examined changes in magnetic resonance imaging (MRI) of temporomandibular joints (TMJ) with anterior displacement disk without reduction (DDwoR) and its correlation to clinical symptoms.

METHODS

190 individuals with DDwoR were evaluated according to Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and MRI. Pain's chronicity/intensity and limited mouth opening (locking) were correlated with: TMJ degeneration (MRI T1), effusion (T2), disc's shape and position (proton density).

RESULTS

In 103 TMJ with DDwoR, hemiconvex shape (41.6%), sclerosis (45.6%) and mild effusion (47.6%) were the most prevalent findings. There was not association (p > .05) between: different DDwoR positions with pain's intensity/chronicity; effusion with locking. Disk deformation was associated with degeneration (p = .034) and pain's intensity (p = .006). Locking was associated with degeneration (p = .05).

CONCLUSIONS

Condylar osteodegeneration is often related to DDwoR. Locking by DDwoR is associated with severe levels of chronic pain and articular disk deformation.

Impacts of the COVID-19 pandemic on the routine of Brazilian oral radiologists

OBJECTIVE

To analyze the challenges and impacts of COVID-19 on the routine of Brazilian oral radiologists regarding changes in biosafety protocols, number of patients and staff, the flow of acquisition, and availability of images.

METHODS

Structured digital questionnaires with questions related to the impacts of the COVID-19 pandemic on Oral Radiology were applied and analyzed. Descriptive statistical analysis was used to describe the items included in the survey, and means and standard deviations were calculated to describe continuous variables and frequency percentages to describe categorical data.

RESULTS

A high number of Brazilian oral radiologists continued to work in the pandemic period, with little or no change in their working hours. Digital flow and teleradiology are in most of their workplaces and the changes imposed by the pandemic will be incorporated and permanent, according to most of the participants in this study.

CONCLUSIONS

The COVID-19 pandemic brought important impacts on radiology clinics, with changes in the flow of patients, in the service and in the type of exam performed. In addition, adaptation to biosafety standards became necessary, with a significant increase in spending on personal protective equipment.

Assessment of marginal gaps and image quality of crowns made of two different restorative materials: An in vitro study using CBCT images

Background

The present study assessed the quality of images and the presence of marginal gaps on cone-beam computed tomography (CBCT) images of teeth restored with all-ceramic and metal-ceramic crowns and compared the gap sizes observed on CBCT images with those obtained on micro-CT images.

Methods

Thirty teeth restored with metal-ceramic and all-ceramic crowns, properly adapted and with gaps of 0.30 and 0.50 mm, were submitted to micro-CT and CBCT scans. Linear measurements corresponding to the marginal gap (MG) and the absolute marginal discrepancy (AMD) were obtained. The objective assessment of the quality of CBCT images was performed using the contrast-to-noise ratio (CNR), and the subjective assessment was defined by the diagnoses made by five examiners regarding the presence or absence of gaps.

Results

The measurements were always higher for CBCT, with a significant difference regarding AMD. No significant difference in image quality was observed using CNR between the crowns tested. Low accuracy and sensitivity values could be observed for both crowns.

Conclusion

Marginal mismatch measures were overestimated in CBCT images. No difference in image quality was observed between the crowns. The correct diagnosis of gaps was considered low, irrespective of crown type and gap size.

Bone and gingival tissue thicknesses of maxillary anterior teeth with and without a metal post: a cone beam computed tomographic study

The objective of this retrospective study was to evaluate buccal bone and gingival thickness measurements obtained from cone beam computed tomographic (CBCT) images of maxillary anterior teeth with and without metal posts. A convenience sample of 71 CBCT images of healthy maxillary anterior teeth and 61 CBCT images of maxillary anterior teeth with a metal post were selected from a database. Eight tomographic measurements (4 bone thicknesses and 4 gingival thicknesses) were performed in the parasagittal section of each tooth, perpendicular to the tooth axis. The Mann-Whitney U test was used to compare these thicknesses, and the Spearman correlation coefficient was calculated for correlation of age with sex. Statistically significant differences were observed for almost all measurements (P < 0.05); the CBCT images of teeth with metal posts displayed lower bone thickness values and higher gingival thickness values. No statistically significant correlations were observed between the thickness measurements and age. However, significantly higher bone thickness values were observed in men (P < 0.05). Cone beam computed tomographic images of teeth with metal posts showed differences in mean bone and gingival measurements compared to teeth without metal posts, suggesting a possible interference of metal artifacts.

Artifacts caused by titanium implants in CBCT images of the mandible: an experimental study

This study evaluated the quantity of metal artifacts produced by dental implants placed in different mandibular regions using various cone beam computed tomography (CBCT) protocols. Titanium implants were placed in 4 regions (incisor, canine, premolar, and molar) of an artificial mandible and subjected to CBCT examinations with the mandibular model placed in different positions within the field of view (FOV) and imaged with different FOV and voxel sizes. An axial section of the cervical region of each implant was selected for artifact quantification. The artifacts were measured by normalizing the actual standard deviation (ASD) of the voxel values. Kruskal-Wallis and Student-Newman-Keuls tests were used to compare the tooth regions and the different positions of the mandible. The Wilcoxon test was used to compare changes in FOV and voxel size. The intraobserver agreement was calculated using the intraclass correlation coefficient. The significance level was 5%. The incisor region showed significantly more artifacts than other regions (P = 0.0315). No statistically significant difference was found when the position of the mandible varied within the FOV (P = 0.7418). Smaller FOV and smaller voxels produced more artifacts (P < 0.0001). The quantity of metal artifacts was affected by FOV and voxel size as well as by anatomical region. Variation of the mandible location within the FOV did not affect the artifacts as defined by the normalized ASD of the voxel values.

Cirurgia paraendodôntica com retro-obturação utilizando MTA Repair HP®: análise tomográfica longitudinal prospectiva de dois casos clínicos

Aim: To evaluate, tomographically, in two clinical cases, the effect of the new MTA formulation of the Angelus, the MTA Repair HP, in the contribution to remission of periapical lesions in paraendodontic surgery, as well its physical properties and manipulation. Case report: Patient R.C.R, 57, attended at the Faculty of Dentistry of the Federal University of Juiz de Fora for evaluation of periapical lesion in the element 11. It was observed, at the clinical and radiographic exams, endodontic treatment and a circumscribed, unilocular and radiolucid area at the apex of the tooth. It was requested a CBCT exam (I-Cat®, Imaging Sciences International, Hatfield, Pennsylvania, USA), which confirmed the presence of the lesion and rupture of the buccal cortical plate. Thus, it was performed curettage, apicectomy, retropreparation and retrofilling with the described cement. It was solicited two additional CBCT exams at the period of three and five months post-operative. Patient R.J.G.M, 46, with mean complain of pain, increased intraoral volume and purulent discharged in the upper left arch. The clinical and radiographic exams revealed fistula and refractory lesion, despite the endodontic treatment of the tooth 25. A CBCT exam was done and it was observed a circumscribed hypodense area, around the apex of the 25, with rupture of the buccal cortical plate. It was suggested the same surgical treatment described in the case above. It was performed two more CBCT exam, at three and five months after the procedure. Discussion: The MTA Repair HP was developed from the necessity of a more biocompatible material with the dental structures in the retrograde filling process. This product helps in the remission of periapicals lesions and in the new formation of the periodontum components; also it has the advantages of longer setting time, not causing the darkening of the coronary portion and easier manipulation. Conclusion: Regarding the remission of the lesions, it was noticed the generation of calcified tissue across the periods of three and five months. Regarding the manipulation and application, it was not observed any improvement related to the addition of the plasticizer. However, it was noticed a shorter setting time, making it difficult to insert the material.

Evaluation of the dimensions, morphology, and position of the mandibular condyles in individuals with neurofibromatosis 1: a case-control study

OBJECTIVES

The aim of this study was to evaluate the mandibular condyles of neurofibromatosis 1 (NF1) individuals without facial plexiform neurofibroma using cone beam computed tomography images.

MATERIALS AND METHODS

Eighty cone beam computed tomography scans (160 mandibular condyles) were analyzed: 40 from NF1 individuals (study group) and 40 from individuals without NF1 (control group). The anteroposterior and mediolateral dimensions, height, and volume of the mandibular condyles were measured. The mandibular condyles were classified according to their morphology: healthy (absence of morphological changes), with flattening (loss of rounded contour of at least one of the surfaces), with erosion (loss of continuity of the cortical bone), with osteophyte (exophytic formation of the condyle surface), and with sclerosis (any increase in the cortical thickness in the load-bearing areas). Furthermore, the position of the mandibular condyles in relation to the joint fossa in an anteroposterior view was classified as anterior, concentric, or posterior.

RESULTS

The study group had a higher anteroposterior dimension of the mandibular condyles compared with the control group (p < 0.05). There were no differences in condylar morphology and position between both groups (p > 0.05). The morphological alterations were not associated with sex or age in any group evaluated (p > 0.05). For both groups, the concentric position was the most common. For the study group, there was a significant difference in the condylar position between the sides (p < 0.05).

CONCLUSIONS

NF1 individuals without facial plexiform neurofibroma present a high prevalence of condyles with a large anteroposterior dimension and asymmetric position in the joint fossa. However, no morphological and volumetric changes were observed in the mandibular condyles of them.

CLINICAL RELEVANCE

The knowledge of the TMJ alterations in individuals with NF1 is important to establish an evaluation protocol, which would allow early intervention if indicated.

Clinical and tomography evaluation of periodontal phenotypes of Brazilian dental students

BACKGROUND

The periodontal phenotype (PP) plays an important role in the function, esthetics, and maintenance of periodontal health and has a great influence in periodontal, restorative, and dental implant therapies.

AIM

The aim of this study was to conduct a clinical evaluation of the PP and its morphometric variations through the cone-beam computed tomography (CBCT), from dentistry students with periodontal health.

MATERIALS AND METHODS

Sixty students were examined, and the clinical parameters of probing depth and width of keratinized tissue (WKT) in the upper anterior segment were accessed. The gingival thickness was evaluated as thick or thin, through the translucency of the periodontal probe through the marginal gingiva. By convenience sample, 13 students were selected to assess bone thickness and gingival thickness and biological width through the previous CBCT examination.

RESULTS

The most prevalent PP, according to the classification by De Rouck et al., was the thick scalloped (55%), and using the classification of Kao and Pasquinelli, the thick PP was most common (73,3%). The thick PP in both the classifications was more prevalent in both genders and the WKT was significantly higher in the thick-flat scalloped PP. The bone thickness was always greater than the gingival thickness in CBCT examinations both in the measures 1 mm and 3 mm above the bone crest. The average of the biological width measurement was 2.02 mm.

CONCLUSIONS

The thick PP was most prevalent in the sample studied, and the gingival thickness was always thinner than the bone thickness in the measures evaluated.

Quantitative assessment of artefacts and identification of gaps in prosthetic crowns: a comparative in vitro study between periapical radiography and CBCT images

OBJECTIVES

To evaluate, in an in vitro study, the quantity of artefacts generated by two different restorative materials, and to determine the diagnostic accuracy of cone beam CT (CBCT) scans and periapical radiographs in identifying gaps in prosthetic crowns.

METHODS

A total of 30 teeth restored with metal-ceramic (n = 15) and all-ceramic (n = 15) crowns, properly adapted and with 0.30- and 0.50 mm gaps, underwent CBCT exams (with voxel sizes of 0.25 and 0.30 mm) and periapical radiographs. The artefacts generated by two different crowns were quantified and compared by the Mann-Whitney test. In addition, five examiners evaluated the presence or absence of gaps in periapical radiographs and CBCT images. The accuracy of tests was determined by the area under the receiver operatring characteristic curve and these values were compared by using the Kruskal-Wallis test.

RESULTS

There was no significant difference in artefact values between the different restorative materials and the different resolutions of CBCT images. Regarding the accuracy of the tests evaluated, periapical radiography and CBCT with voxel size 0.25 mm showed the best performance for smaller gaps (0.30 mm). For larger gaps (0.50 mm), all exams tested showed the same performance.

CONCLUSIONS

Periapical radiography was still the most cost-beneficial method for the diagnosis of maladaptation in dental restorations. CBCT exams did not improve accuracy in detecting gaps in prosthetic crowns.

Intra-articular calcifications of the temporomandibular joint and associations with degenerative bone alterations

Purpose

The purpose of this study was to use cone-beam computed tomography (CBCT) images to determine the prevalence of calcifications in the temporomandibular joint (TMJ) and to evaluate any associations between the presence of such calcifications and degenerative bone alterations of the TMJ, sex, or age.

Materials and Methods

In this retrospective study, 1,058 CBCT exams were analyzed, and data regarding the presence and quantity of calcifications, the affected side, any degenerative alterations of the condyle, sex, and age were collected. To evaluate associations between the presence of calcifications and sex or age, the Fisher exact test or the Spearman correlation coefficient, respectively, was used. To assess the association between the presence of calcifications and joint bone alterations, the chi-square and Fisher exact tests were used. The significance level adopted was 5% (P<0.05).

Results

Twenty-eight patients (2.7%) presented with TMJ calcifications, including 23 women (82.1%) and 5 men (17.9%). Significant correlations were found between the presence of calcifications and age (P<0.05) and between the presence of calcifications and the presence of condylar alterations (P<0.05), with 73.2% of patients with bone alterations having TMJ calcifications.

Conclusion

It may be concluded that, although rare (with a prevalence of only 2.7%), intra-articular calcifications are associated with both degenerative bone alterations and age.

Challenges for the dental radiology clinic in times of the COVID-19 pandemic

This letter addresses the challenges for the dental radiology clinic in times of the COVID-19 pandemic. It highlights the use of teleradiography and mobile devices, as well as the proper care in disinfecting these equipments. As there are still no specific therapies for COVID-19, biosafety measures that promote containment and prevent the spread of the virus are crucial to stop the outbreak and control a possible new infectious peak.

Relationship of maxillary posterior roots to the maxillary sinus and cortical bone: a cone beam computed tomographic study

This study evaluated the relationship between the apices of maxillary posterior teeth (second premolar, first molar, and second molar) and the maxillary sinus floor (MSF) and maxillary cortical bone (MCB). Cone beam computed tomographic (CBCT) scanning was used to analyze 1660 roots from 678 teeth and determine the shortest distance between the root apex and MSF and between the root apex and buccal and palatal cortices of maxillary bone. The root apices were classified based on their relationship to the MSF: type 1, the root apex protruded into the maxillary sinus; type 2, the root apex was from 0 mm (touching the MSF) to 1 mm below the MSF; and type 3, the root apex was greater than 1 mm below the MSF. As the age of the subjects increased (older than 40 years), there was a significantly greater proximity of the teeth to the MCB (P < 0.05) and less proximity of second molars to the MSF (P = 0.005). First and second molars each presented a high prevalence of root apices that protruded into the maxillary sinus (type 1), 47.8% and 43.8%, respectively. Second premolars were more frequently classified as type 3 (71.7%) than first and second molars. The mesiobuccal root of the maxillary second molar was the root closest to the MSF, while the maxillary first molar was the tooth closest to the MCB.

Anatomical evaluation of the relationship between the maxillary posterior teeth and maxillary sinus

Knowledge of the anatomical relationships between the maxillary sinus (MS) and posterior teeth is important to prevent complications when endodontic or oral surgical procedures are performed. The aim of this study was to evaluate the relationships between the root apices of maxillary posterior teeth and the MS floor. Three oral radiologists evaluated 851 posterior teeth (1969 roots) imaged with cone beam computed tomography. The roots were analyzed individually in parasagittal sections, on which the most superior point of the apex was observed. A qualitative evaluation was performed, and each root was assigned a proximity score: 1, root invaginating the MS; 2, root in close contact with the MS floor; 3, root with no relationship with the MS; and 4, root with a measurable proximity to the MS. For roots classified as score 4, the distance to the MS floor was measured (quantitative analysis). Student t tests, 1-way analysis of variance, and simple linear regression analysis were performed (P < 0.05). The qualitative analysis revealed that the mesiobuccal root of the second molar had a pronounced proximity to the MS. The quantitative analysis revealed no differences in distance to the MS between right and left posterior teeth or between the different roots of the same tooth. In relation to the MS, the second molar was positioned closest, followed by the first molar, second premolar, and first premolar. Except for the comparison between mean distances of the second premolar and first molar (P = 0.11), the differences between groups of teeth were statistically significant (P < 0.05). Simple linear regression analysis showed that the more posterior the tooth was in relation to the midline, the shorter the mean distance from the root apex to the MS floor (P < 0.05). The mesiobuccal roots of second molars were closest to the MS. Second molars exhibited the shortest distances between their root apices and the MS and the greatest number of roots that were invaginating or in close contact with the MS. Therefore, second molars require special attention when endodontic or oral surgical approaches involve those regions.

Panoramic versus CBCT used to reduce inferior alveolar nerve paresthesia after third molar extractions: a systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review was to verify whether CBCT in comparison with panoramic radiography reduced the cases of temporary paresthesias of the inferior alveolar nerve (IAN) associated with third molar extractions.

METHODS

The literature search included five databases (PubMed, Scopus, Web of Science, Cochrane, SciELO), in addition to gray literature and hand search of reference list of included studies. Two reviewers independently screened titles/abstracts, and full texts according to eligibility criteria, extracted data and evaluated risk of bias through Revised Cochrane Risk of Bias Tool for Randomized Trials (RoB 2.0). Data were meta-analyzed by comparing CBCT versus panoramic radiographs for number of events (temporary paresthesia after third molar surgery). Fixed effect model was used for non-significant heterogeneity; relative risk (RR) and 95% CI were calculated. The certainty of evidence was evaluated by Grading of Recommendations, Assessment, Development, and Evaluation (GRADE).

RESULTS

Four randomized controlled trials (RCTs) were included in meta-analysis, and for the majority of domains they presented low risk of bias. RR was 1.23 (95% IC: 0.75-2.02; I²: 0%; p = 0.43) favouring panoramic radiography, but without significant effect, and with moderate certainty of evidence.

CONCLUSIONS

We concluded that both interventions had a similar ability to reduce temporary paresthesia of the IAN after third molar surgery with moderate certainty of evidence.

Tomografia computadorizada de feixe cônico como método de avaliação da pneumatização da articulação temporomandibular

Introdução: A pneumatização, considerada um processo fisiológico, são cavidades cheias de ar no interior dos ossos do crânio resultante de áreas de células epiteliais. Objetivo: Determinar a prevalência de pneumatização na fossa articular (PFA) e da eminência articular (PEA) do osso temporal por meio de exames de tomografia computadorizada de feixe cônico (TCFC). Material e métodos: Trezentas e noventa imagens de articulações temporomandibulares foram avaliadas por dois examinadores, devidamente calibrados, com experiência em imagens de TCFC. Nos casos em que foi detectada pneumatização, esta foi classificada de acordo com o tipo (unilocular e multilocular) e lateralidade (unilateral ou bilateral). Resultados: A PFA ou a PEA foi diagnosticada em 97 (49,74%) pacientes. Destes pacientes, 61 (31,3%) apresentaram PFA e 36 (18,5%) PEA. Em relação à lateralidade, na PFA, 36 (59%) apresentaram a condição unilateralmente e 25 (41%) bilateralmente. Dentre os pacientes com PEA, 24 (66,7%) apresentaram a condição unilateralmente e 12 (33,3%) bilateralmente. A pneumatização foi correlacionada entre os lados pelo coeficiente de correlação de Spearman e foi significativa para os casos multiloculares (fossa articular: rs=0,52 / p<0,0001 e eminência articular: rs=0,42 p<0,0001). Conclusão: A pneumatização da região temporomandibular é uma característica relativamente comum e, apesar de não necessitar de tratamento, a observação é fundamental para evitar complicações do tratamento ou diagnóstico errôneo na região.

Association between bruxism and temporomandibular disorders in children: A systematic review and meta-analysis

BACKGROUND

Bruxism in children and its relation to the development of temporomandibular disorders (TMD) has not been clearly determined yet.

AIM

The objective of this systematic review was to evaluate the possible association between bruxism and TMD in children.

DESIGN

Seven databases were searched, and 497 articles were assessed. Methodological quality was assessed through Newcastle-Ottawa Scale. The meta-analysis was performed with the articles in which extraction of data was possible and the summary effect measure through odds ratio (OR) and respective 95% confidence intervals (CIs). Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) was used to assess the certainty of evidence.

RESULTS

Ten cross-sectional studies were included in the systematic review. Of these, 8 showed a statistically significant association between bruxism and TMD. Seven studies however presented a high risk of bias. The meta-analysis was performed with 3 articles and obtained an OR of 2.97 (95% CI ranging from 1.72-5.15), indicating that children with bruxism are 2.97 times more likely to present TMD, with very low level of certainty defined by GRADE.

CONCLUSIONS

Although the studies showed high risk of bias, the qualitative analysis of individual studies showed that the children with bruxism have greater chance of developing TMD.

Double mandibular canal and triple mental foramina: detection of multiple anatomical variations in a single patient

Having complete information about a patient's mandibular canal and mental foramen is fundamental to performing safer procedures and avoiding intraoperative and postoperative complications. Cone beam computed tomography (CBCT) produces accurate images for the analysis of maxillomandibular bone structures and is widely used in dentistry. The aim of this study is to report a case of mandibular bifid canal associated with triple mental foramina that was revealed with CBCT images. A 45-year-old woman was referred for a CBCT scan of remaining bone quantity to assist in preoperative implant planning. The patient had reported problems related to anesthesia during extraction of the mandibular right second and third molars. Examination showed bilateral bifurcation of the mandibular canal, from the mandibular foramen to the gonial angle. In addition, exteriorization of the mandibular canal was noticed in 3 regions; that is, there were 3 distinct mental foramina. Clinicians must be aware of these anatomical variations in the mandibular region during dental procedures to avoid complications such as difficulty in obtaining anesthesia or postoperative sensory dysfunction.

Avaliação da qualidade no atendimento aos clientes das clínicas de Radiologia Odontológica: uma visão do empresário

Introdução: As clínicas de radiologia são prestadoras de serviços que realizam exames por imagem odontológicos e seus proprietários devem se preocupar com a qualidade dos serviços prestados. Objetivo: Avaliar, por meio da percepção do empresário, a qualidade no atendimento prestado aos clientes das clínicas de radiologia odontológica da cidade de Juiz de Fora (Minas Gerais, Brasil). Material e Métodos: Foi aplicado um questionário estruturado, desenvolvido para avaliar a autopercepção do empresário quanto à qualidade no atendimento. Esse instrumento possuia 24 questões, incluindo os seguintes tópicos: dados gerais, infraestrutura, recursos humanos, biossegurança e radioproteção, logística, estratégia de marketing e avaliação dos clientes. Resultados: Cerca de 90% das clínicas aceitaram responder o questionário. Pode-se observar que o tempo de mercado das clínicas é bastante variável (um a 27 anos) e, em relação à formação dos seus gestores, apenas dois (25%) eram administradores de empresa. Quando questionados sobre se seus atendentes receberam algum tipo de capacitação, seis (75%) clínicas responderam que sim, mas que se tratou apenas de treinamento interno. Seis (75%) clínicas afirmaram que os pacientes aguardavam no máximo 10 minutos para serem atendidos e que cumpriam o prazo de entrega dos exames e laudos. Em relação ao marketing, o contato telefônico, a internet e as redes sociais foram as estratégias mais frequentes das clínicas participantes. Conclusão: Pode-se concluir que as clínicas de radiologia são geridas, na maioria das vezes, por profissionais que não possuem formação em administração, mas que se preocupam em garantir um atendimento de qualidade.

Uso de métodos não invasivos para avaliação da espessura muco-gengival: a tecnologia a favor do diagnóstico

O objetivo no presente estudo foi realizar uma revisão atualizada da literatura sobre os diferentes métodos não invasivos utilizados para avaliação da espessura muco-gengival. O biotipo gengival é considerado um dos principais elementos de influência no resultado do tratamento estético. Pacientes com gengiva espessa demonstram ser mais resistentes à recessão gengival após terapia cirúrgica e/ou restauradora. Em contrapartida, pacientes com biotipo fino apresentam maior risco de recessão, sendo necessário, muitas vezes, o enxerto de tecido conjuntivo. O palato é a principal área doadora para enxerto de tecido conjuntivo subepitelial, sendo que a determinação da espessura da mucosa palatina é de grande importância para a previsibilidade dos procedimentos cirúrgicos. Existem diversos métodos para mensurar a espessura muco-gengival, alguns considerados invasivos, como: a avaliação transgengival (ou transmucosa); e outros, mais recentes, considerados não invasivos, como as imagens seccionais de ultrassom, tomografias computadorizadas ou imagens de ressonância magnética. Apesar de diversos estudos demonstrarem resultados positivos do uso de exames por imagens para avaliação da espessura dos tecidos muco-gengivais, concluiu-se que os métodos invasivos ainda parecem ser os mais utilizados.

Evaluation of different soft tissue-simulating materials in pixel intensity values in cone beam computed tomography

OBJECTIVE

This study aimed to evaluate different materials as soft tissue simulators and the influence of soft tissues in cone beam computed tomography.

STUDY DESIGN

Images of 5 piglet heads were acquired with intact soft tissues, with the tissues stripped, and with the use of different soft tissue simulators, following the same acquisition protocol. Four different materials were tested, individually or in combination: acrylic, water, utility wax, and expanded polystyrene (EPS). Pixel intensity values of 8 quadrangular regions, that is, upper and lower teeth and alveolar bone, were obtained. The mean values were used for comparison by analysis of variance (ANOVA; α = 5%).

RESULTS

No differences were observed for the "No Material," "EPS," "Acrylic," and "EPS and Wax" groups for the lower anterior and posterior teeth, the upper posterior tooth, and the anterior and posterior bone, and for the "No Material," "EPS," and "EPS and Wax," groups for the lower posterior bone. All groups showed statistical differences for the lower anterior bone and the upper anterior tooth.

CONCLUSIONS

Expanded 2-cm thick polystyrene, with or without 1-cm thick utility wax, was effective for most regions, followed by acrylic 0.5 cm. Soft tissues were not of great influence in most regions. Water was not an effective material for any of the regions.

Evaluation of root canal morphology of maxillary premolars: a cone-beam computed tomography study

The aim of this study was to evaluate the root canal configuration of maxillary premolars using cone-beam computed tomography (CBCT). CBCT images of 999 maxillary premolars from a database were analysed to determine the frequency of the number of roots, root canals and Vertucci's classification. The associations among these variables were evaluated by Chi-square test (P < 0.05). In the first premolars, 42.2% of single-rooted teeth had a type II configuration, whereas 98.7% of 2-rooted teeth showed type IV. In the second premolars, type I was the most prevalent (49.9%). The presence of two roots was more prevalent in first premolars, and the presence of one root was more prevalent in second premolars (P < 0.05). Male patients had a higher percentage of two roots compared with female patients (P < 0.05). Type IV and I was more prevalent in first and second premolars respectively (P < 0.05). There was a high frequency of 2-rooted and single-rooted teeth among maxillary first and second premolars respectively.

In vitro analysis of dental ceramics: evaluation of the radiopacity and chemical composition by raman spectroscopy

Objective: This study compared the radiopacity of different ceramic systems by means of digital radiographs and evaluate the chemical composition of the samples by Raman spectroscopy. Material and Methods: The hypothesis tested was that there was a difference in radiopacity among the tested materials. Specimens were prepared for each ceramic tested: FLD - VM7 (VITA Zahnfabrik), LD - IPS Empress e.max Press (IPS Empress), AL - In Ceram Alumina (VITA Zahnfabrik), ALYZ - In Ceram Zirconia (VITA Zahnfabrik), YZ - Lava All Ceram (3M/ESPE), and MYZ - Zirconzahn (Talladium Brazil). The specimens were radiographed and submitted to radiographic density readings using a histogram tool. The spectrometer coupled to a petrographic microscope was used for Raman spectroscopy measurements. Analysis of variance (ANOVA) and a Tukey post-hoc test were used to compare radiopacity of the different materials. Results: For all tested materials, the radiopacity showed statistically significant differences, except YZ and MYZ. Lava All Ceram and ZirkonZahn had high radiopacity values and VM7 and IPS Empress e.max Press showed lower radiopacity than human dental structures. Conclusion: It was possible to conclude that radiopacity is closely linked to ceramic chemical composition.KeywordsDental ceramics; Radiopacity; Raman spectroscopy test; Restorative dentistry.

Effect of anatomical region on the formation of metal artefacts produced by dental implants in cone beam computed tomographic images

OBJECTIVES

To quantitatively compare metal artefacts produced by implants in different maxillomandibular regions on cone beam CT (CBCT) images.

METHODS

A total of 200 implants selected from CBCT examinations were divided into four groups: Group 1 (n = 50)-implants located in the anterior maxilla; Group 2 (n = 50)-implants located in the posterior maxilla; Group 3 (n = 50)-implants located in the anterior mandible and Group 4 (n = 50)-implants located in the posterior mandible. The implants were further classified as isolated or adjacent to other implants. Three axial reconstructions were selected for each sampled implant (apical, middle and cervical). On each slice, the artefacts produced by the implants were counted. The Mann-Whitney test was used to compare the variables between groups. The Kruskal-Wallis and Student-Newman-Keuls tests were used to compare the axial reconstructions.

RESULTS

The mandible showed a greater number of artefacts than the maxilla (apical image: p = 0.0024; middle image: p < 0.0001). The anterior region produced more artefacts than the posterior region (apical image: p = 0.0105; middle image: p < 0.0316). There was no significant difference in the number of artefacts between isolated and adjacent implants, and the cervical image was most affected by artefacts.

CONCLUSIONS

Dental implants always produce metal artefacts in CBCT images, and these artefacts are affected by the anatomical location in the dental arch.

Correlation between Endodontic Infection and Periodontal Disease and Their Association with Chronic Sinusitis: A Clinical-tomographic Study

INTRODUCTION

The proximity of the roots of maxillary posterior teeth to the maxillary sinus floor can be associated with the development of chronic maxillary sinusitis (CMS). Therefore, this study evaluated the correlation between the presence of endodontic infection and periodontal disease in maxillary posterior teeth and the presence of CMS.

METHODS

A total of 83 patients (159 maxillary sinuses) were selected and underwent clinical dental examination to assess tooth mobility and pulp condition. In addition, cone-beam computed tomography was performed to evaluate the presence of periapical lesion and periodontal bone loss, and measure the distance from the root apex to the cortical of the maxillary sinus. The maxillary sinuses were divided into 2 groups: CMS and no maxillary sinusitis. Data were analyzed using χ² test and binary logistic regression analysis (P < .05).

RESULTS

Periodontal disease was positively associated with CMS, leading to a 3.45-fold higher association between these disorders (P < .05). CMS was significantly more common in patients with periodontal disease or endodontic infection in close proximity with the maxillary sinus. Periodontal disease or endodontic infection that was more distant from the maxillary sinus was more common in patients with no maxillary sinusitis (P < .05). To the extent that the tooth is more distant from the maxillary sinus floor, the chance of presenting CMS is reduced up to 2.5-fold (P < .05).

CONCLUSION

Periodontal disease and proximity to the maxillary sinus are more common in cases of CMS, requiring a dental assessment and cone-beam computed tomography evaluation in patients with CMS with ineffective treatment.

Three-dimensional analysis of impacted maxillary third molars: A cone-beam computed tomographic study of the position and depth of impaction

Purpose

The classification of impacted maxillary third molars (IMTMs) facilitates interdisciplinary communication and helps estimate the degree of surgical difficulty. Thus, this study aimed to develop a 3-dimensional classification of the position and depth of impaction of IMTMs and to estimate their prevalence with respect to gender and age.

Materials and Methods

This cross-sectional retrospective study analyzed images in sagittal and coronal cone-beam computed tomography (CBCT) sections of 300 maxillary third molars. The proposed classification was based on 3 criteria: buccolingual position (buccal, lingual, or central), mesial-distal position (mesioangular, vertical, or distoangular), and depth of impaction (low, medium, or high). CBCT images of IMTMs were classified, and the associations of the classifications with gender and age were examined using analysis of variance with the Scheffé post-hoc test. To determine the associations among the 3 classifications, the chi-square test was used (P<.05).

Results

No significant association of the classifications with gender was observed. Age showed a significant relationship with depth of impaction (P=.0001) and mesial-distal position (P=.005). The most common positions were buccal (n=222), vertical (n=184), and low (n=124). Significant associations among the 3 tested classifications were observed.

Conclusion

CBCT enabled the evaluation of IMTMs in a 3-dimensional format, and we developed a proposal for a new classification of the position and depth of impaction of IMTMs.

Analysis of the correlation between dental arch and articular eminence morphology: a cone beam computed tomography study

OBJECTIVE

The aim of the study was to assess the correlation between the morphology of the dental arches (DAs) of patients with normal occlusion and of the articular eminence (AE) by using cone beam computed tomography (CBCT).

STUDY DESIGN

CBCT scans of 60 patients were evaluated in terms of height and inclinations (angles α, β, and δ) of the AE. DAs were classified according to their shapes (tapered, square, ovoid), and their perimeters, widths, and depths were measured. One-way analysis of variance, Pearson's correlation coefficients, and simple and multivariate linear regression models were used for the calculations.

RESULTS

The ovoid arch was the most predominant shape (n = 66/120). Inclination of the AE (angle β) had the greatest difference between DA shapes, with this angle usually being greater in the ovoid arch and smaller in the square arch (P < .05). The height of the AE presented greater correlation with DA measurements, with tapered arches having the most significant correlations (P < .05). DA depth had no influence on AE measurements (P > .05). The perimeter and width of the DAs had some influence (P < .05).

CONCLUSIONS

Correlations were found between the DA and AE morphologies. The correlations should be taken into consideration, although the results do not prove absolute association between the variables. Whenever possible, the morphologic features of DAs should be preserved to avoid possible changes in AE.

Sinusite odontogênica: uma revisão de literatura

Objetivo: realizar uma revisão de literatura sobre a anatomia e proximidade do seio maxilar com raízes dentárias, etiologia, microbiologia, sintomatologia, diagnóstico e tratamento das sinusites odontogênicas. Material e Métodos: foi realizada uma busca na literatura na base de dados PubMed, usando as palavras chave sinusite odontogênica, dente e seio maxilar. Trinta e seis artigos foram incluídos. Resultados: os artigos revisados sugerem que a iatrogenia e a periodontite apical são os principais fatores etiológicos da sinusite odontogênica. Os dentes mais próximos ao seio maxilar são os segundos pré-molares e molares superiores. Conclusão: a sinusite odontogênica é uma doença com etiologia, microbiologia e sintomatologia bem definidas. O diagnóstico errado pode levar a falhas no tratamento e sintomatologia persistente.

Influence of lip retraction on the cone beam computed tomography assessment of bone and gingival tissues of the anterior maxilla

OBJECTIVE

To evaluate the influence of lip retraction on cone beam computed tomography (CBCT) assessment of bone and gingival tissues on the labial surface of the anterior maxilla.

STUDY DESIGN

A retrospective study was conducted using measurements of bone and gingival tissues collected from 120 maxillary incisors. The thicknesses of the bone and gingival tissues of different regions were measured on CBCT images, with and without a lip retractor. The thicknesses of the gingival tissues obtained from CBCT were correlated with measurements performed by clinical probing.

RESULTS

The thickness of bone in the more cervical region presented a higher mean value for exams performed with a lip retractor (P = .021). The thickness of bone found a significant correlation with the thickness of the gingiva (P ≤ .020) with a lip retractor in CBCT exams. The thickness of the gingival tissue obtained from CBCT scans with lip retraction found significant correlations with those obtained clinically (P ≤ .001).

CONCLUSIONS

The use of lip retractors is a simple and reliable practice that allows the measurement of gingival tissues on CBCT images. This practice can exempt a patient from an invasive clinical procedure for measuring the thickness of the gingival tissue for implant cases of the anterior segment.

Salivary Periodontopathic Bacteria in Children and Adolescents with Down Syndrome

OBJECTIVE

To assess and compare salivary periodontopathic bacteria between groups of Down syndrome and non-Down syndrome children and adolescents.

MATERIALS AND METHODS

This study included a sample of 30 Down syndrome children and adolescents (G-DS) and 30 age- and sex-matched non-Down syndrome subjects (G-ND). Clinical examination determined the gingival bleeding index (GBI) and plaque index. Unstimulated whole saliva samples were collected from all participants. The fluorescence in situ hybridization (FISH) technique identified the presence and density of eight periodontopathic bacteria in saliva. The statistical analysis included chi-square and Mann-Whitney U tests.

RESULTS

In the G-DS group, bleeding on probing was more frequent (p = 0.037) and higher densities of Campylobacter rectus (p = 0.013), Porphyromonas gingivalis (p = 0.025), Treponema denticola (p = 0.026), Fusobacterium nucleatum (p = 0.013), Prevotella intermedia (p = 0.001) and Prevotella nigrescens (p = 0.008) were observed. Besides, in the G-DS, the densities of bacteria from the orange complex were significantly higher in the age group 3-7 years for F. nucleatum (p = 0.029), P. intermedia (p = 0.001) and P. nigrescens (p = 0.006). C. rectus was higher in the age group 8-12 years (p = 0.045).

CONCLUSION

The results showed that children and adolescents with Down syndrome have higher susceptibility to periodontal disease and number of periodontopathic bacteria.

Zirconia Abutment Supporting All Ceramic Crowns in the Esthetic Zone: Interim Results of a Prospective Study

AIM

This prospective study evaluated peri-implant tissues around all-ceramic crowns fabricated using CAD/CAM technology.

MATERIAL AND METHODS

Twenty-five patients received pre-fabricated zirconia implant abutments with CAD/CAM zirconia copings in the esthetic zone. Implants were evaluated at baseline, and at 3 and 6 months in function.

RESULTS

Radiographic analyzes showed stable bone crest around the implants. Esthetics were more favorable as time lapsed (p > 0.05). Bleeding Index was constant in all time intervals. Plaque index reduced from 3 to 6 months.

CONCLUSION

The all-ceramic CAD/CAM crowns were clinically, radiographically and esthetically stable during the study period.

Assessment of mandibular posterior regional landmarks using cone-beam computed tomography in dental implant surgery

The aim of this study has been to evaluate and correlate the anatomical features of the posterior mandibular region (submandibular fossa depth, bone height and thickness, and mandibular canal corticalization) to improve accident prevention and allow safe planning in implantology. Four parasagittal sections of cone-beam computed tomography (CBCT) from 100 patients were bilaterally analyzed. Linear measurements of the submandibular fossa depth, bone height and thickness were performed. The submandibular fossa was also classified into non-influential undercuts and influential undercuts for implant placement. Mandibular canal corticalization was also evaluated and classified according to the visualization. Data on patient age and gender were also collected. Forty-one scans (41%) were from male patients, and 59 (59%) were from female patients. Patient age ranged between 18 and 84 years, with an average age of 51.37 years. The submandibular fossa depth and implant bone thickness had a significant effect on the variability of the sample (46.1% and 22.3%, respectively). The submandibular fossa depth was quite variable, and the highest values were observed in the posterior regions. In 18.27% of the cases, the presence of the fossa directly influenced implant placement, considering a bone height of 10mm (standard implant). A significant correlation was observed between fossa depth and bone thickness. Thus, greater attention should be paid to thick ridges; although thick ridges are favorable, they may be associated with deeper submandibular fossae. The mandibular canal was the most influential anatomical structure in the premolar region due to the reduced bone height in this region and the greater difficulty in viewing the canal, and the submandibular fossa was the most influential structure in the molar region due to lower bone height leading up to the fossa and the greater fossa depth in this region. Therefore, CBCT is an important tool for assessing the mandibular region and planning for safe implant installation in the posterior mandible. Furthermore, comprehensive evaluation of the characteristics of this region is necessary, as the variables - submandibular fossa depth, bone height and thickness, and mandibular canal corticalization - are related and must be considered together when planning.

Magnetic resonance images of patients with temporomandibular disorders: prevalence and correlation between disk morphology and displacement

Using magnetic resonance imaging (MRI), this study aimed to evaluate the morphology of the articular disc of the temporomandibular joint (TMJ) in patients with temporomandibular disorder (TMD). There were 218 TMJ of 109 assessed patients; 88 were females and 21 males, and all were diagnosed as symptomatic for temporomandibular disorder. The articular disc positions were classified in the normal position and with anterior disc displacement with and without reduction. Regarding the morphology, the discs were classified as follows: biconcave (normal), biplanar, rounded, biconvex, folded, thickening in the posterior band, thickening in the anterior band and hemiconvex. The results indicated that females were the most affected by morphological changes of the articular disc (p=0.008/Cramer's V=0.295). There was no statistical significance when correlating the disc morphology with the sides (right and left). There was a significant correlation between the position and morphology of the articular disc (p<0.001/Cramer's V=0.609), and in the normal position of the discs presenting biplanar and biconcave morphologies. In TMJ with anterior displacement of the disc with reduction (ADDR), there was a greater correlation with rounded, hemiconvex and biconvex morphologies. Already in the TMJ with displacement without reduction (ADDWR), there was a higher prevalence of folded discs. It can be concluded that morphological changes in the disc are influenced by the type of displacement, and more serious deformations are associated with ADDWR cases.

Evaluation of the correlation between disc displacements and degenerative bone changes of the temporomandibular joint by means of magnetic resonance images

The aim was to evaluate the correlation between disc displacements and degenerative bone changes in magnetic resonance images (MRI) of 112 patients of both genders, with signs and symptoms of temporomandibular disorder. For this purpose, a calibrated examiner evaluated 224 MRI by assigning scores for the displacement of the disc and degenerative bone changes. Disc displacement was found in 58.42% of the temporomandibular joints (TMJs) evaluated. Anterior displacement of the disc with reduction was the most common, occurring in 67.18% cases of joints with disc displacement. Degenerative bone changes were observed in 53.94% of the TMJs analysed. There was significant correlation between disc displacement with reduction and condylar flattening, disc displacement without reduction and condylar flattening, disc displacement without reduction, and associated degenerative bone changes (flattening and erosion, flattening, osteophyte and erosion; flattening and osteophytes, erosion and sclerosis, flattening and sclerosis, flattening, osteophytes and sclerosis). The correlation between advanced cases of disc displacement and the occurrence of degenerative bone changes emphasises the importance of MRI for an accurate diagnosis and development of an appropriate treatment plan and in cases in which clinical examination is not sufficient for these purposes.

An artificial multilayer perceptron neural network for diagnosis of proximal dental caries

OBJECTIVE

To evaluate if the application of an artificial intelligence model, a multilayer perceptron neural network, improves the radiographic diagnosis of proximal caries.

STUDY DESIGN

One hundred sixty radiographic images of proximal surfaces of extracted human teeth were assessed regarding the presence of caries by 25 examiners. Examination of the radiographs was used to feed the neural network, and the corresponding teeth were sectioned and assessed under optical microscope (gold standard). This gold standard served to teach the neural network to diagnose caries on the basis of the radiographic exams. To gauge the network's capacity for generalization, i.e., its performance with new cases, data were divided into 3 subgroups for training, test, and cross-validation. The area under the receiver operating characteristic (ROC) curve allowed comparison of efficacy between network and examiner diagnosis.

RESULTS

For the best of the 25 examiners, the ROC curve area was 0.717, whereas network diagnosis achieved an ROC curve area of 0.884, indicating a sizeable improvement in proximal caries diagnosis.

CONCLUSION

Considering all examiners, the diagnostic improvement using the neural network was 39.4%.

The forensic importance of frontal sinus radiographs

The identification of unidentified human remains through the comparison of antemortem and postmortem radiographs has found wide acceptance in recent years. Reported here is the forensic case of an unidentified adult male who had died as the result of a traffic accident, after which the body was identified by matching images of ante- and postmortem radiographs of the frontal sinus. A general discussion on identification using frontal sinus radiographs is presented, highlighting the reliability of this method, in reference to the uniqueness of the frontal sinus in humans. However, it also notes a few difficulties, especially in reference to the X-ray technique in cases where antemortem radiographs are available and a potentially larger number of anatomical, pathological or traumatic features are present. The comparison of frontal sinus outlines is recommended when it may become necessary to provide quantitative substantiation for forensic identification based on these structures.

Radiopacity of calcium hydroxide cement compared with human tooth structure

AIMS: All materials added to teeth should present an adequate radiopacity to allow the detection of secondary caries. Usually, in extensive cavities, base materials like calcium hydroxide cement are used for the purpose of protecting the pulp. In an attempt to improve the efficiency of radiographic detection of this material, this study aimed to determine the radiopacity of three calcium hydroxide cements and to compare the radiopacity of these materials with dentin and enamel. METHODS: Radiographs were taken of 1-mm thick specimens of three calcium hydroxide cements: Hydro-C, Dycal and Life, an aluminium stepwedge, a lead foil, and one 1-mm thick human tooth slice. Densitometric measurements were obtained after radiographic processing. The radiopacity values of the calcium hydroxide cements, dentin and enamel were expressed in terms of the equivalent thickness of aluminium. RESULTS: The analysis of variance indicated statistically significant difference only for Life, which presented the lowest radiopacity when compared to the other cements. However, all cements and enamel possessed a radiopacity equivalent to 2mm Al, while dentin presented a radiopacity equivalent to 1mm Al. CONCLUSION: All tested cements presented a similar radiopacity to that of enamel and they meet the ISO 4049 specifications.