Influence of surgeon experience on implant placement in guided surgeries: A systematic review and meta-analysis of randomized clinical trials

STATEMENT OF PROBLEM

Guided surgical techniques in implant dentistry use virtual planning to accurately position implants. Understanding the effect of a surgeon's experience on guided surgery is essential to ensure successful outcomes.

PURPOSE

The purpose of this systematic review and meta-analysis of randomized clinical trials was to evaluate the influence of a surgeon's experience on the accuracy of implant positioning in guided surgery for completely or partially edentulous patients.

MATERIAL AND METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines, searches were conducted in the PubMed, Scopus, Web of Science, EMBASE, Cochrane Library, SciELO, and nonpeer-reviewed literature databases. Studies that met the population, intervention, control, and outcome (PICO) strategy were included: a completely or partially edentulous maxilla or mandible, guided surgery performed by experienced and inexperienced surgeons, and assessing implant positioning accuracy. A random-effects meta-analysis with a 95% confidence interval was conducted using Stata 15.1. The risk of bias was assessed with the Cochrane risk-of-bias tool for randomized trials (RoB2), and evidence certainty was evaluated using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) tool. The study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42022302288).

RESULTS

Three articles from 2017 to 2020 encompassing 43 participants (22 men and 21 women) with a mean age of 61.2 years and a total of 150 implants were included. No significant difference was found between experienced and inexperienced surgeons in terms of angular, cervical, or apical deviations of the implants (95% confidence interval, P<.05). The difference between surgeons regarding positioning accuracy was less than 0.01 degrees for angular deviation, 0.35 mm for apical deviation, and 0.16 mm for cervical deviation. Low heterogeneity was observed for angular deviations (Q P=.021, I2=34%, and t2<.001) and cervical deviations (Q P=.18, I2=45%, and t2=.064). High heterogeneity was observed for apical deviations (Q P<.001, I2=87% and t2=.522). The overall bias risk was moderate, with the evidence certainty ranging from low to moderate.

CONCLUSIONS

In guided surgery, the surgeon's experience did not significantly impact the occurrence of deviations in implant positioning.

Prevalence and Characterization of External Cervical Resorption Using Cone Beam Computed Tomography

INTRODUCTION

The aim of this study was to assess the prevalence of external cervical resorption (ECR) and characterize the cases of ECR using cone beam computed tomography (CBCT).

METHODS

High-resolution CBCT scans of 6216 patients (2280 males and 3936 females), consecutively acquired during the period July 2021 to March 2022, were analyzed. Identified cases of ECR were characterized by 3 evaluators regarding lesion height, circumferential spread, portal of entry proximity to root canal, stage, location, and width.

RESULTS

In a total of 38 patients and 40 teeth, ECR cases demonstrated an incidence of 0.61%. The median age of the patients was 39 years. Prevalence of ERC was 0.78% among males and 0.50% among females. The most affected teeth were the maxillary incisors and canines. The most frequent characteristics of the lesion were: extension up to the cervical third (47.5%), more than 270° circumferential spread (42.55%), probable pulpal involvement (57.5%), progressive stage (65%), supracrestal (52.1%) and mesial (34.7%) localization of >1 mm in size (52.1%) portals of entry. Cases with greater longitudinal involvement also showed greater circumferential progression (P = .008). There was no association between portal of entry location and bone crest or ECR reparative phase (P = .42). Inter-rater agreement ranged from good to very good. No association between portal of entry and ECR progression was observed.

CONCLUSIONS

ECR showed low prevalence in the Brazilian population, affecting mostly anterior maxillary teeth of patients within a wide age range. CBCT allowed characterization of ECR lesions with good interobserver agreement.

Influence of CBCT-derived panoramic curve variability in the measurements for dental implant planning

OBJECTIVE

To investigate whether the curve markings performed prior to panoramic and cross-sectional reconstructions can influence the planning of oral implants.

METHODS

Twenty oral radiologists landmarked the reference panoramic curves in 25 CBCT scans of the mandible. Bone height was measured on the resulting cross-sectional slices in the edentulous region of the lower first molar. The following data were recorded: (1) number of landmarks used to build each reference curve; (2) shape of the reference curve (inverted "U", inverted "V" or "horseshoe"); and (3) measurement in the first molar region. The data were assessed for variability based on the number of landmarks, the shape of the reference curve, and the measurements obtained.

RESULTS

The number of landmarks used to guide the panoramic reconstruction varied among radiologists (p < 0.05), but most of them draw curves in inverted "U" shape (68-100%). The reproducibility of the measurements taken in the edentulous mandibular first molar region was excellent (84.7%). The number of landmarks and the shape of the curve did not have a significant influence on the reproducibility of the measurements (p > 0.05).

CONCLUSION

Variations of the operator-dependent steps during the panoramic reconstructions occur but do not play a significant part changing the measurements taken for oral implant planning.

Panoramic Radiography vs. CBCT in the Evaluation of the Maxillary Third Molar Roots

Background and Objectives: A comprehensive understanding of the position of third molar roots and adjacent structures, such as the maxillary sinus (MS), is essential for safe extractions. Diagnostic imaging plays a fundamental role in achieving accurate treatment planning. This study aimed to compare panoramic radiography (PR) and cone-beam computed tomography (CBCT) for the evaluation of maxillary third molar roots and their relationship with the MS. Materials and Methods: Two trained radiologists evaluated third molar images. The number of roots, morphology (fused/conical, divergent, dilacerated, or atypical), and their relationship with the MS in PR and CBCT were registered. Descriptive and inferential statistics were performed using the weighted Kappa test. Results: Regarding the number and morphology of the roots, Kappa values showed moderate (κ = 0.42) and fair agreement (κ = 0.38), respectively. Regarding the proximity with the MS, most of the roots showed close contact (30.6%), or 1/3 of root superimposition (35%), in PR evaluation, while in CBCT, the third molars were in contact with the MS floor (32%), and with alveolar domes (27.2%). Conclusions: PR is a moderately reliable image technique to identify the number of roots and root morphology of maxillary third molars. PR, however, does not provide any radiographic signs that clearly indicate the anatomical relationship between the maxillary third molar roots and the maxillary sinus detected in CBCT images.

Radiographic dental age estimation applying and comparing Demirjian's seven (1973) and four (1976) teeth methods

To apply Demirjian's seven (1973, D7) and four (1976, D4) teeth methods in a sample of Brazilian children and compare their performances for age estimation. Panoramic radiographs of 1200 children (600 females and 600 males) were collected from Southeast Brazil. The children were equally distributed (n = 60 females and 60 males) between age intervals of 1 year between 6 and 15.9 (mean age = 10.9; standard deviation [SD]: 2.9) years. D7 and D4 dental age estimation methods were applied by two observers and were compared based on their error rates (error = estimated age-chronological age). Both methods overestimated the chronological age (p < 0.0001). D7 led to overestimations of 0.71 (p < 0.0001) in females and 0.83 (p < 0.0001) in males, while the overestimations with D4 were 0.14 (p = 0.0067) and 0.73 (p < 0.0001) for females and males, respectively. The mean age estimated by D7 was 11.7 (SD: 3.1) years, while for D4, it was 11.3 (SD: 3.3) years. Intra- and interobserver agreement was ≥ 0.98. D4 optimized the performance of radiographic dental age estimation compared to D7. Improvements were reflected in the total sample and separately for female and male children from Southeast Brazil.

Cone beam computed tomography (CBCT) referrals in paediatric patients: A 24-month retrospective study in two radiological centers in Campinas, Brazil

PURPOSE

To evaluate the CBCT referrals in paediatric patients over a 24-month period.

METHODS

A retrospective study was conducted in two radiological centers in Campinas, Brazil. Patients were divided into three age groups: G1: age under 10 years, G2: age between 10 and 12 years, and G3: age over 12 years. The following data were collected: patients' age and sex, localisation, reasons for referral and dental specialty responsible for the request of CBCT exams.

RESULTS

Data from 367 patients were assessed. CBCT was used more frequently in the Group 3 (58.9%). There was significant association between the region of the exam and age group (P < 0.05), with a higher percentage of exams in the maxilla for the age over 12 years (35.6%) than that of up to 10 years (50.9%) and between 10 and 12 years (51.1%). Alterations were observed in 79.3% of the exams and 47.4% showed impacted teeth with significant association with the increase in age group (P < 0.05). Of the total number of exams, (55.3%) were requested in Orthodontics followed by Oral Surgery (30.0%) and Paediatric Dentistry (9.5%).

CONCLUSIONS

It can be concluded that CBCT exams were indicated frequently for the age over 12 years. The presence of impacted teeth represented the main reason for referrals and Orthodontics was the dental specialty that indicated CBCT with higher frequency.

Effect of decompression and online transmission on the dimensional changes of .stl files generated by intra-oral scanning

Intraoral scans became part of the virtual planning in Dentistry. In the new scenario of digital workflows, dental clinics and laboratories had to establish an online communication that requires the compression, decompression, and transmission of 3D files. Knowledge about the effects of these procedures on the dimensional properties of the files is fundamental to ensure a more realistic virtual planning. The aim of this study was to assess the influence of 3D file compression, decompression, and online transmission on the dimensional properties of dental models from intraoral scanning. Intraoral scan files in.stl format of 50 patients were selected from the database of a dental radiology clinic, with 25 of these patients with mixed dentition and 25 with permanent dentition. The maxilla and mandible scans of each patient were included in the study, generating a total of 100 files. A folder with the 100 files was created and replicated six times with different labels (A, B, C, D, E, F), totaling a sample number of 600 files. Folder A was compressed by WinZip and then decompressed. Folder B went through the same process, but the step of compression and decompression by WinZip was repeated 10 times. The folders C, D, E, F were sent, respectively, through the platforms WeTransfer, Dropbox, Google Drive, and OneDrive, then each of them was downloaded in their respective platforms. After the six folders went through the compression process and were sent by the platforms, each file in the folder was compared with its original file by superimposing the 3D images and identifying the dimensional deviation in the compressed file in relation to the original file. We observed that there were no differences between the six groups regarding dimensional changes from the compression, decompression and online transmission processes. The lack of dimensional changes was observed for the sets of permanent and deciduous. teeth We concluded that it is possible to compress, decompress, and transfer.stl format files online without causing dimensional distortions in the 3D model.

Evaluation of the dosimetry and centralization of scout-view function in CBCT

This study evaluated the centralization of the region of interest (ROI) in acquisition of the CBCT images, when the freely positionable scout-view (SV) function is applied. Additionally, the dosimetry of the acquired images was assessed in the SV function alone as well as in complete tomographic image in two different fields of view (FOV) (50x50 and 78x150mm). A three-location device was created to accommodate the dosimeters and the specimens, in the right, middle and left location during image acquisition. For dose assessment, thermoluminescent dosimeters were irradiated within the FOV and analyzed in a portable reader. For ROI evaluation, three specimens of gutta-percha stick were placed on the same device and the CT scans were acquired (CBCT OP 300 Maxio device, 90kV, 13mA, 85 µm voxel size, FOV of 50X50mm), with and without the SV, in three positions (3-9, 1-7 and 5-11 o’clock), simulating different regions of the mouth. Two image evaluations were performed, an objective and subjective. There was a slight percentage increase (1.36% to 1.40%) of the radiation dose with the use of SV. The distances were significantly greater in the images acquired without SV (p < 0.05). Every image obtained with SV was classified as being at the FOV’s center. In conclusion, the results demonstrated that SVs function is effective to centralize the ROI in the FOV, increasing the scan precision and avoiding repetitions due to positioning errors.

Applicability of Willems method for age estimation in Brazilian children: performance of multiple linear regression and artificial neural network

Background

Dental age estimation of children may be necessary in the clinical and forensic fields. In the former, it may contribute to the investigation of dental development and biological maturation. In the latter, dental age estimation may support the Court in several circumstances, such as adoption and unidentified bodies of deceased children. This study aimed to apply Willems method for dental age estimation of children from Southeastern Brazil. The second aim of the study was to test the performance of the method modeled with multiple linear regression (MLR) and artificial neural network (ANN). The sample consisted of 1000 panoramic radiographs of female (n = 500) and male (n = 500) Brazilian children. The individuals were evenly distributed through ten age intervals of 1 year from 6 to 15.99 years. Dental development was classified with the 7-teeth technique of Demirjian et al. (1973), followed by age calculation with Willems method (2001). The difference between chronological and estimated ages was quantified for the original Willems model and for the MLR and ANN models.

Results

For females and males, the overall difference found with Willems original model was 0.27 and 0.28, respectively. With MLR and ANN, the overall differences were 0.54 and 0.35, and 0.26 and 0.24, respectively. The ANN was able to reduce half of the mean error of female age predictions up to 100%. The same phenomenon occurred in 1/3 of the males. Despite the improvements of the ANN model to specific age groups, the original Willems model performed similar or better in 40% of the studied age intervals. All the models showed the worse age predictions in the interval between 15 and 15.99 years (p < 0.001).

Conclusions

Willems method remains optimal and applicable after 20 years since original development. The ANN model might be an option for future improvements (depending on sex and age interval).

Effect of cone-beam computed tomography metal artefact reduction on incomplete subtle vertical root fractures

Purpose

This study compared the accuracy of detection of incomplete vertical root fractures (VRFs) in filled and unfilled teeth on cone-beam computed tomography images with and without a metal artefact reduction (MAR) algorithm.

Materials and Methods

Forty single-rooted maxillary premolars were selected and, after endodontic instrumentation, were categorized as unfilled teeth without fractures, filled teeth without fractures, unfilled teeth with fractures, or filled teeth with fractures. Each VRF was artificially created and confirmed by operative microscopy. The teeth were randomly arranged, and images were acquired with and without the MAR algorithm. The images were evaluated with OnDemand software (Cybermed Inc., Seoul, Korea). After training, 2 blinded observers each assessed the images for the presence and absence of VRFs 2 times separated by a 1-week interval. P-values<0.05 were considered to indicate significance.

Results

Of the 4 protocols, unfilled teeth analysed with the MAR algorithm had the highest accuracy of incomplete VRF diagnosis (0.65), while unfilled teeth reviewed without MAR were associated with the least accurate diagnosis (0.55). With MAR, an unfilled tooth with an incomplete VRF was 4 times more likely to be identified as having an incomplete VRF than an unfilled tooth without this condition, while without MAR, an unfilled tooth with an incomplete VRF was 2.28 times more likely to be identified as having an incomplete VRF than an unfilled tooth without this condition.

Conclusion

The use of the MAR algorithm increased the diagnostic accuracy in the detection of incomplete VRF on images of unfilled teeth.

Dosimetric evaluation for temporomandibular joint cone beam computed tomography exams using different field of view

Objectives.To optimize the absorbed organ dose in relation to the field of view for temporomandibular joint examinations in four cone beam computed tomography devices.Methods.An anthropomorphic adult head and neck phantom, and 192 LiF dosimeters (TLD-100) were used. The dosimeters were placed in the region corresponding to the lens, parotid glands, submandibular glands, and thyroid. Small, medium and large FOVs were selected on Orthopantomograph OP300 Maxio, PaX-i3D Smart, ORTHOPHOS XG, and i-CAT Next Generation device when it was possible.Results.A wide range of absorbed dose values was recorded for all organs due to the different exposure parameters of each device. The radiosensitive organ with the highest dose was the parotid glands. The devices with 5 × 5 cm FOV recorded a lower dose in this protocol, while for the device without a small FOV (≤5 × 5 cm), the lowest dose was observed with the large FOV (6 × 16 cm).Conclusions.We recommend a double exposure with an FOV of 5 × 5 cm in the OP300 Maxio, PaX-i3D Smart, and ORTHOPHOS XG device, while in the i-CAT Next Generation device, a single exposure FOV of 6 × 16 cm is indicated.

Biosafety devices to control the spread of potentially contaminated dispersion particles. New associated strategies for health environments

Dental procedures produce a large amount of spatter and aerosols that create concern for the transmission of airborne diseases, such as Covid-19. This study established a methodology with the objective of evaluating new associated strategies to reduce the risk of cross-transmission in a health environment by simulating spread of potentially contaminated dispersion particles (PCDP) in the environment. This crossover study, was conducted in a school clinic environment (4 clinics containing 12 dental chairs each). As a positive control group (without barriers), 12 professionals activated at the same time the turbine of dental drill, for one minute, with a bacterial solution (Lactobacillus casei Shirota, 1.5x10⁸ CFU/mL), which had been added in the cooling reservoir of the dental equipment. In the experimental groups, the professionals made use of; a) an individual biosafety barrier in dentistry (IBBD) which consists of a metal support covered by a disposable PVC film barrier; b) a Mobile Unit of Disinfection by Ultraviolet-C, consisting of 8 UV lamps-C of 95W, of 304μW/cm² of irradiance each, connected for 15 minutes (UV-C) and; c) the association between the two methods (IBBD + UV-C). In each clinic, 56 Petri dishes containing MRS agar were positioned on the lamps, benches and on the floor. In addition, plates were placed prior to each test (negative control group) and plates were also placed in the corridor that connects the four clinics. In the groups without barrier and IBBD + UV-C the passive air microorganisms in Petri dishes was also evaluated at times of 30, 60, 90 and 120 minutes after the end of the dental’s drill activation. The mean (standard deviation) of CFU of L. casei Shirota for the positive control group was 3905 (1521), while in the experimental groups the mean using the IBBD was 940 (466) CFU, establishing a reduction on average, of 75% (p<0.0001). For the UV-C group, the mean was 260 (309) CFU and the association of the use of IBBD + UV-C promoted an overall average count of 152 (257) CFU, establishing a reduction on average of 93% and 96%, respectively (p<0.0001). Considering these results and the study model used, the individual biosafety barrier associated with UV-C technology showed to be efficient strategies to reduce the dispersion of bioaerosols generated in an environment with high rate of PCDP generation and may be an alternative for the improvement of biosafety in different healthy environment.

Maturation stages of the sutures in the median palatine evaluated with cone-beam computed tomography

INTRODUCTION

This study aimed to evaluate the influence of age, sex, and facial growth patterns on the maturation stage of midpalatal sutures.

METHODS

We selected 90 total skull cone-beam computed tomography scans and divided them into the following 3 groups: brachyfacial (n = 30), mesofacial (n = 30), and dolichofacial (n = 30). These groups were determined using Ricketts VERT 3-dimensional cephalometric analysis. All patients were aged ≥18 years and were divided into those aged ≥30 years and >30 years. The maturational stage of the median palatine sutures was determined by evaluating the central transverse axial dimension in the maxillary-mandibular palate. Maturational stages were classified as A, B, C, D, and E.

RESULTS

Of the 90 images reviewed, 55 (61.1%) were female patients, and 35 were male patients (38.9%). The age of patients ranged from 18 to 59 years, with 55 patients aged <30 years (61.1%) and 35 aged ≥30 years (38.9%). Regarding the maturational stages, 3.3% of brachyfacial, 6.7% of mesiofacial, and 16.7% of dolichofacial subjects (P = 0.032) were classified as stages B and C.

CONCLUSIONS

The patients' facial patterns were found to be a significant signal for the maturation stage of midpalatal sutures. Adult dolichofacial patients are the most likely to have stage B and C.

Effect of image acquisition parameters on the radiopacity of bulk-fill and nanocomposite resins

OBJECTIVE

This study evaluated the radiopacity of 2 bulk-fill resins (SonicFill and Filtek Bulk Fill) and a nanocomposite (Filtek Z350 XT) resin compared with enamel, dentin, and aluminum as measured with different exposure parameters.

STUDY DESIGN

Resin disks were radiographed together with a 1-mm human tooth section and an aluminum stepwedge, at exposure times of 0.2 and 0.32 s, and source-image (S-I) distances of 30 and 40 cm, using complementary metal oxide semiconductor (CMOS) and photostimulable phosphor systems. Grayscale values were measured using ImageJ software. Paired Student t tests were used to compare the effect of the receptor on grayscale values for each material. Analysis of variance was used to evaluate the effects of receptor, exposure parameters, and the resins on radiopacity.

RESULTS

All resins exhibited greater radiopacity scores than enamel and were significantly different from each other. Filtek Z350 produced the lowest radiopacity values, whereas SonicFill produced the highest. The radiopacity values were higher on images acquired with CMOS receptors. Receptor type, exposure time, S-I distance, and material, as well as many interactions of these parameters, affected the radiopacity of the resins.

CONCLUSION

The tested resins complied with ISO 4049. Exposure parameters and digital receptors affected their radiopacity.

Alveolar antral artery in edentulous patients and their visualization through cone beam computed tomography

OBJECTIVE OF THE STUDY

The aim of this study was to assess the anatomical features of the alveolar antral artery (AAA) in edentulous patients using cone beam computed tomography (CBCT).

PATIENTS

The sample consisted of 191 CBCT scans of maxillary sinuses (n=382) of male (n=59) and female (n=132) edentulous patients (age: 38-89 years).

MATERIAL AND METHODS

The images were analyzed in Dolphin™ 11.9 software. Visualization, location, and diameter of the AAA was registered.

RESULTS

AAA was present in 88.5% of the assessed maxillary sinuses. Bilateral visualization was predominant 77% (P<0.0001). The mean vertical distance from the most anterior part of the AAA to the sinus floor was 7.9±6mm in female patients (both sides) and 12±7.22mm on the right side and 10.9±6.86mm on the left side in males. The mean diameter of the AAA was 1.2±0.7mm on both sides in females. In males, the diameter was significantly (P<0.05) larger: 1.5±0.62mm on the right side and 1.4±0.69 on the left side in females.

CONCLUSION

The AAA had a higher visualization rate, better visualization, and larger diameter when it was present bilaterally in male and female patients.

Odontogenic infection as a predisposing factor for pathologic disorder development in maxillary sinus

OBJECTIVE

To investigate an association between odontogenic infections (OI) and maxillary sinuses pathologic disorder (MSPD). The distance between the sinus floor and the root apex of upper posterior teeth was also assessed.

METHODS

Out of 4,402 cone beam computed tomography scans, 230 were selected, and 431 teeth were evaluated regarding the presence of OI: bone loss with furcation involvement, periapical and endodontic-periodontal lesions. The maxillary sinuses were assessed regarding the presence of MSPD, which was considered as mucosal thickening, opacification of the sinus and mucous retention cyst.

RESULTS

There was a significant association between OI and MSPD (p < .001). Periodontal bone loss with furcation involvement, periapical lesions and endodontic-periodontal lesions increased the risk of opacification of the sinuses by 11.6, 34.1 and 228.8 times, respectively. The frequency of the different types of MSP showed not to be associated with a group of teeth or dental root. Conversely, the presence of MSP was associated with a significant shorter distance between the palatine root apex and the sinus floor (p < .001).

CONCLUSION

There is a relationship between infectious process of teeth and MSPD. The proximity between the apex of palatine roots and the maxillary sinus floor showed to be a predisposing factor for MSPD.

Oral and cranio-maxillofacial trauma in children and adolescents in an emergency setting at a Brazilian hospital

BACKGROUND/AIMS

Very few studies have been performed to evaluate cranio-maxillofacial trauma diagnosed in hospitals in children and adolescents. The aim of this study was to perform an analysis of oral and cranio-maxillofacial trauma in the aforementioned population.

MATERIALS AND METHODS

A hospital-based retrospective study, which reviewed 1438 patient records, was conducted at the "Teresina Emergency Hospital", Brazil. Data regarding demographics, day of the week on which trauma occurred, type of injury, etiology, anatomic trauma site, time of hospital admission, and associated comorbidities (or injuries) were collected.

RESULTS

There were 1092 (75.9%) males and 346 (24.1%) females. The largest group was adolescents aged between 13 and 18 years (956, 66.5%). The majority lived in urban areas (69%). Trauma occurred most frequently during the week. The most prevalent etiology was road traffic accidents involving motorcycles (771, 53.6%) causing facial and skull fractures (598, 41%). The most prevalent soft tissue lesions were facial abrasions (49%), followed by injuries to the cheek (16.7%). Comorbidities associated with craniofacial trauma were present in 82%, with complications from traumatic brain injuries being the most prevalent (65.6%) Dental trauma was recorded in only 81 cases (5.6%).

CONCLUSION

Male adolescents living in urban areas were most affected by craniofacial trauma. The most common cause was road traffic accidents involving motorcycles, resulting in facial and skull fractures. Complications from traumatic brain injuries were the most common associated injuries.

Presence of Cells in Fresh-Frozen Allogeneic Bone Grafts from Different Tissue Banks

Bone replacement materials have been widely used to reconstruct atrophic jawbones. Based on previous reports demonstrating the presence of viable cells in bone blocks even after processing by musculoskeletal tissue banks for orthopedic use, the aim of this study was to evaluate the presence of cells in bone blocks from three Brazilian tissue banks for maxillary reconstructions. All samples were processed by the respective tissue banks, according to the guidelines of the Brazilian National Sanitary Surveillance Agency. Three samples were removed from each block for subsequent histological processing and stained using hematoxylin & eosin. Further evaluation included section staining by the Feulgen method and ultrastructural analysis using scanning electron microscopy (SEM). Light microscopy images from all bone samples showed presence of osteocyte-like cells in all groups and intense Feulgen staining, demonstrating presence of DNA in bone even after tissue processing. The ultrastructural analysis showed red blood cells in lacunae within the bone tissue. In conclusion, despite bone tissue processing by the musculoskeletal tissue banks, cells may be found within the bone used for allogeneic grafts.

Unusual Case of Graphite Tattoo in a Pediatric Patient: Clinical Presentation and Differential Diagnosis

Graphite tattoo, a rare finding in children, is characterized by a localized blue-grey macule of variable sizes and shapes. Intraoral graphite implantation may cause this pigmentation through accidental injury with a graphite pencil. The purpose of this paper is to report an unusual case of graphite tattoo involving the anterior palate region in a seven-year-old girl. A diagnosis was made based on clinical and radiographic examinations and histopathology features. This report also highlights the importance of differential diagnosis and management of oral benign and malignant pigmented lesions in children.

Intraobserver and interobserver reproducibility in linear measurements on axial images obtained by cone-beam computed tomography

PURPOSE

This study was performed to investigate the intra- and inter-observer variability in linear measurements with axial images obtained by PreXion (PreXion Inc., San Mateo, USA) and i-CAT (Imaging Sciences International, Xoran Technologies Inc., Hatfield, USA) CBCT scanners, with different voxel sizes.

MATERIALS AND METHODS

A cylindrical object made from nylon with radiopaque markers (phantom) was scanned by i-CAT and PreXion 3D devices. For each axial image, measurements were taken twice in the horizontal (distance A-B) and vertical (distance C-D) directions, randomly, with a one-week interval between measurements, by four oral radiologists with five years or more experience in the use of these measuring tools.

RESULTS

All of the obtained linear measurements had lower values than those of the phantom. The statistical analysis showed high intra- and inter-observer reliability (p=0.297). Compared to the real measurements, the measurements obtained using the i-CAT device and PreXion tomography, on average, revealed absolute errors ranging from 0.22 to 0.59 mm and from 0.23 to 0.63 mm, respectively.

CONCLUSION

It can be concluded that both scanners are accurate, although the linear measurements are underestimations, with no significant differences between the evaluators.

Location and classification of Canalis sinuosus for cone beam computed tomography: avoiding misdiagnosis

The aim of this study was to assess the presence, location and, multiplanar distance of the canalis sinuosus (CS) between the incisive foramen and the anterior maxillary alveolar ridge using cone beam computed tomography (CBCT). Therefore, 500 CBCT maxillary images obtained from male and female patients aged 20 to 80 years were selected to assist in the dental treatment. Low-quality tomographic images were discarded. All images were captured with the i-CATTM Classic tomograph and assessed using the XoranCatTM software. The axial sections were analyzed at the incisive foramen in order to verify the CS presence in laterality and location. Furthermore, linear measurements of the nasal cavity floor, buccal cortical bone, and alveolar ridge crest were made. All the collected data were statistically analyzed. Results show a variation of the CS in relation to the classification and distance of anatomical structures, but no significant difference between the right and left sides. It should be highlighted that CBCT is necessary before invasive procedures in order to preserve important anatomical structures. In conclusion, the location of the CS varies in relation to the alveolar ridge crest and buccal cortical bone, assuming that it is going to be located by the upper lateral incisor palatine.

Cryosurgery as an Effective Alternative for Treatment of Oral Lesions in Children

Children can exhibit a wide variety of oral pathologies, such as oral lesions, bone lesions, tumors, cysts and cutaneous lesions. Different techniques have been described for the treatment of these lesions, but all of them are invasive. This paper presents a series of cases that demonstrate the clinical efficacy of cryosurgery as an alternative to invasive surgical treatments of the most common oral lesions in children. This technique has been well tolerated by patients due to the absence of anesthesia, rapid healing and minimal bleeding. Cryotherapy has many applications in oral medicine and is an extremely useful alternative in patients to whom surgery is contraindicated due to age or medical history. It is a simple procedure to perform, minimally invasive, low-cost and very effective in pediatric dentistry clinic.

Liquid nitrogen cryosurgery for treatment of mucoceles in children

A mucocele is a common benign lesion of the minor salivary gland mucosa that most frequently affects children and young adults. Several treatments have been described in the literature, including liquid nitrogen cryosurgery--a therapeutic alternative for treating mucoceles in children that has many applications in clinical oral pathology. The purpose of this paper was to present the treatment of lower lip mucoceles in 2 children via liquid nitrogen cryosurgery performed without local anesthesia. Also discussed are the mechanisms of action, current protocol of cryosurgery recommended in the management of mucoceles, clinical advantages and disadvantages, clinical outcomes, and pediatric patients' safety.

Accuracy assessment of the axial images obtained from cone beam computed tomography

OBJECTIVE

The aim of this study was to evaluate accuracy of linear measurements assessed from axial tomograms and the influence of the use of different protocols in two cone beam CT (CBCT) units.

METHODS

A cylinder object consisting of Nylon® (Day Brazil, Sao Paulo, Brazil) with radiopaque markers was radiographically examined applying different protocols from NewTom 3G(TM) (Quantitative Radiology s.r.l, Verona, Veneto, Italy) and i-CAT(TM) (Imaging Sciences International, Hatfield, PA) units. Horizontal (A-B) and vertical (C-D) distances were assessed from axial tomograms and measured using a digital calliper that provided the gold standard for actual values.

RESULTS

There were differences when considering acquisition protocols to each CBCT unit. Concerning all analysed protocols from i-CAT(TM) and Newtom 3G(TM), both A-B and C-D distances presented underestimated values. Measurements of the axial images obtained from NewTom 3G(TM) (6 inch 0.16 mm and 9 inch 0.25 mm) were similar to the ones obtained from i-CAT(TM) (13 cm 20 s 0.3 mm, 13 cm 20 s 0.4 mm and 13 cm 40 s 0.25 mm).

CONCLUSION

The use of different protocols from CBCT machines influences linear measurements assessed from axial images. Linear distances were underestimated in both equipments. Our findings suggest that the best protocol for the i-CAT(TM) is 13 cm 20 s 0.3 mm and for the NewTom 3G(TM), the use of 6 inch or 9 inch is recommended.

Atypical case of oral lichen planus in a pediatric patient: clinical presentation and management

Lichen planus (LP) is a mucocutaneous disease of unknown etiology that is relatively common in adults but rarely present in childhood. LP has been documented in dental and medical literature; however, there are few cases with oral involvement in children. The purpose of this paper was to report an unusual case of oral lichen planus involving the upper lip in a 7-year-old girl. A diagnosis was made based on clinical examination and histopathology features. The treatment consisted of topical corticosteroid and intralesional injection. After treatment with an intralesional corticosteroid, a complete re- mission of lesions involving the lip was observed. The 3-year follow-up, however, revealed asymptomatic lichenoid bilaterally affecting the buccal mucosa. The patient is currently under regular review.

Condylar hemangioma: report of a case and review of the literature

According to the World Health Organization, hemangiomas are benign vasoformative neoplasms or developmental conditions of endothelial origin. The body region is the most commonly affected part of the mandible, and only 4 cases of condylar tumors have been reported in the literature to date. The differential diagnosis between high and low flow vascular lesions is crucial for successful treatment, decreasing the occurrence of serious intraoperative hemorrhage. The clinical, radiographic, and pathological features of an intraosseous vascular lesion in the mandibular condyle in a 22-year-old male are presented, and the differential diagnostic aspects between hemangioma, vascular malformation, and high or low flow lesions are discussed.