Evaluation of the Correlation Between the Structural Parameters of Trabecular Bone in CBCT and the Primary Stability of Dental Implants.

PURPOSE: To investigate the relationship between the structural parameters of trabecular bone obtained from CBCT imaging and the primary stability of dental implants. MATERIALS AND METHODS: Sixty patients underwent implant placement followed by primary stability evaluation via measurement of the insertion torque (IT) and the implant stability quotient (ISQ). Gray values (GV) and the fractal dimension (FD) were also measured using pretreatment CBCT images. RESULTS: FD values showed a positive and significant relationship with ISQ and IT values (P = .017 and P = .004, respectively). Additionally, there was a positive and significant correlation between GV and IT (P = .004) as well as between GV and ISQ (P = .010). FD and GV showed a considerable difference between the maxillary and mandibular jaws and were higher in the mandible. Only FD was significantly different between men and women and was higher in men. In the two age groups (older and younger than 45 years), only GV was considerably higher in people older than 45 (P < .05). CONCLUSIONS: Both fractal dimension and gray values obtained from CBCT are efficient methods for predicting the primary stability of the implant due to their relationship with ISQ and IT values.

Comparison of Diagnostic Quality of Multidetector Computed Tomography and Cone-Beam Computed Tomography in High and Low Resolution Modes for Assessment of the Nasal Cavity.

Background: We aimed to compare the diagnostic quality of multidetector computed tomography (MDCT) and cone-beam computed tomography (CBCT) in high (HR) and low (LR) resolution modes for assessment of the nasal cavity and paranasal sinuses. Methods: This in vitro study was conducted on 5 dry human skulls by using a CBCT and a MDCT scanner in HR and LR modes to assess their diagnostic quality for 21 anatomical landmarks of the nose. The quality of images was evaluated by two oral and maxillofacial radiologists and a dentist using a four-point Likert scale of (I) poor, (II) decreased, (III) good, and (IV) excellent. Data were analyzed by STATA at 95% confidence interval. The Chi-square test was applied to compare the quality of visualization of landmarks based on the type of scanner. Results: The diagnostic quality of HR CBCT and CT for the majority of landmarks was higher than that of LR CBCT and CT (P<0.05). The diagnostic quality of HR CBCT for agger nasi cells (P=0.010), olfactory cleft (P=0.032), sphenoethmoidal recess (P=0.032), and nasolacrimal duct (P=0.014) and LR CBCT for the middle turbinate (P=0.046) and middle meatus (P=0.031) was significantly higher than that of MDCT. Conclusion: The diagnostic quality of HR CBCT and CT for the majority of the landmarks in the nasal cavity and paranasal sinuses was higher than that of LR CBCT and CT. For the majority of landmarks, the diagnostic quality of CBCT and CT was the same; while for some landmarks, the diagnostic quality of HR and LR CBCT was higher than HR and LR CT. In general, CBCT has high efficacy for evaluation of the paranasal sinuses and the nasal cavity, and provides diagnostic information comparable to those provided by CT, but with a much lower radiation dose.

Association of root morphology of mandibular second molars on panoramic-like and axial views of cone-beam computed tomography.

BACKGROUND: Knowledge about the anatomy and morphology of the root canal system is essential for successful surgical and non-surgical root canal treatments. However, precise assessment of the root morphology and anatomy is not often possible on two-dimensional radiographs. This study aimed to investigate the association of root morphology of mandibular second molars on panoramic-like and axial views of cone-beam computed tomography (CBCT). METHODS: This cross-sectional study evaluated 1,231 CBCT scans of mandibular second molars obtained between October 2018 and February 2022 that were retrieved from the archives of a private radiology clinic. Panoramic-like images were reconstructed from the CBCT scans. The root morphology of mandibular second molars was classified on panoramic-like images as type 1, 2, 3, 4, or 5. The root pattern on axial CBCT images was classified into three types of single, double and C-shaped. The association of root morphology on panoramic-like and axial CBCT views was analyzed by the Chi-square test and Fisher's exact test at 0.05 level of significance. RESULTS: Of all, 62.7% of mandibular second molars were type 1; out of which, 97.3% had a double-root pattern on axial CBCT images. Also, 28.6% of them were type 2; of which, 92.6% had a double-root pattern. Moreover, 3.9% were type 3; of which, 47.9% had a C-shaped pattern; 0.9% were type 4, and 45.5% of them showed a single-root pattern; 3.8% were type 5 with 76.6% of them showing a single-root pattern. The prevalence of C-shaped canals was higher in females, and most C-shaped canals had a C3 pattern. CONCLUSION: Root morphology on panoramic-like CBCT views had a strong association with the root canal pattern on axial CBCT views. According to the results, mandibular second molars with a type 3 morphology on panoramic-like CBCT images are highly probable to have a C-shaped canal.

Cone-beam computed tomography assessment of the root canal morphology of primary molars.

BACKGROUND: This study aimed to assess the root canal morphology of primary molars using cone-beam computed tomography (CBCT). METHODS: This cross-sectional study evaluated 60 maxillary and mandibular primary first and second molars on CBCT scans of patients retrieved from the archives of Hamadan School of Dentistry between 2018-2020. The teeth were evaluated regarding the number of roots and canals, canal type according to the Vertucci's classification, and root surface concavities. Data were analyzed descriptively and by independent t-test. RESULTS: The most frequent number of canals and roots in the maxillary right and left first molars was 3 canals (60%) and 3 roots (80%). These values were 4 canals (80%) and 5 canals (50%) with 3 roots in the maxillary right and left second molars, respectively, 4 canals (100%) and 2 roots (50%), and 3 canals (60%) and 2 roots (50%) in mandibular right and left first molars, respectively, and 4 canals (92.3%) and 3 roots (61.5%) in mandibular right and left second molars. Vertucci's type IV was the most common canal type in mesial and distal canals, type I was the most common in mesiobuccal, mesiolingual, distobuccal, and distolingual, and types I and II were the most common in the palatal canal. The maximum and minimum concavities were noted in the buccal (26.7%) and mesial (8.3%) surfaces, respectively. CONCLUSIONS: A wide variation exists in the number of roots and canals of maxillary and mandibular primary molars, which calls for further attention in treatment of such teeth.

Prevalence of bifid variations of the mandibular canal in an Iranian population using cone-beam computed tomography.

OBJECTIVES: Bifid mandibular canal (MC) is an anatomical variation of the MC. This study aimed to assess the prevalence and shape of bifid MC in an Iranian population. MATERIALS AND METHODS: A total of 681 patients who had undergone cone-beam computed tomography (CBCT) for different purposes between 2018 and 2020 were evaluated. After detection, bifid MCs were classified into four types forward, buccolingual, dental, and retromolar. CBCT images were assessed by two oral and maxillofacial radiologists. Data were analyzed by SPSS using an independent t-test and Chi-square test. RESULTS: Bifid MC was found in 23 (3.4%) out of 681 patients, with a mean age of 32.21 years. Ten patients (1.5%) had a bifid MC on the right side, 6 (0.9%) on the left side, and 7 (1%) bilaterally. However, no significant correlation was found between laterality and the prevalence of bifid MC (P > 0.05). Bifid MC was found in 8 males (34.8%) and 15 females (65.2%). Gender had no significant correlation with the prevalence of bifid MC (P > 0.05). Forward type was the most common (n = 8, 1.2%) followed by buccolingual (n = 5, 0.73%), dental (n = 2, 0.3%), and retromolar (n = 1, 0.14%) types. CONCLUSION: According to the present results, bifid MC was not uncommon in the Iranian population of the present study, and forward type was the most common, followed by buccal and then dental bifid MCs. There was no significant correlation between sex and age with bifid MC but bifid MC was detected more frequently in females than males, and it was seen unilaterally in a higher percentage of the cases.

Effect of photobiomodulation therapy with different wavelengths on bone mineral density in osteoporotic rats.

Osteoporosis is associated with severe pain, bone deformity, fracture, and bone loss. It is important to find strategies to prevent bone resorption and treat osteoporosis. This study sought to assess the effect of photobiomodulation therapy (PBMT) with different wavelengths on bone mineral density (BMD) in osteoporotic rats. This animal study evaluated 63 adult female rats. The rats underwent ovariectomy to induce osteoporosis. Ovariectomized rats were randomly divided into 9 groups of control (OC), treatment with zoledronic acid alone (0.02 mg/kg), and treatment with 660 nm, 810 nm, and 940 nm PBMT alone (3 times a week for 6 weeks, energy density of 4 J/cm2), and combined with zoledronic acid. The healthy control group (HC) only underwent sham surgery. The rats underwent cone-beam computed tomography (CBCT) 52 days after the first treatment session to measure their BMD according to the gray value (GV) of images. To assess the biomechanical properties of bone, the resected bones were subjected to 3-point bending test (3-PBT). The experimental groups had significant differences with the OC group regarding radiographic and biomechanical properties of bone (P < 0.05), indicating a healing course. No significant difference was noted between the experimental groups treated with different laser wavelengths and those treated with zoledronic acid (P > 0.05). In the condition of this study, it was found that PBMT at a constant energy density of 4 J/cm2 with 660-, 810-, and 940-nm wavelengths is effective for enhancement of bone mineral density and biomechanical properties. No significant difference was noted between different wavelengths of diode laser regarding radiographic and biomechanical properties of bone.

Effect of different intracanal posts and exposure parameters on detection of vertical root fractures by cone-beam computed tomography.

This study evaluated the effect of different amperage values and voxel sizes of two CBCT scanners on VRF detection in the presence of different intracanal posts. After post-space preparation, VRFs were induced in half of the samples of 20 maxillary premolars. Five different intracanal posts were passively placed in each root canal. Samples were scanned using CS 9300 and Cranex3D with two different voxel sizes and amperage setting in each unit. The diagnostic sensitivity, specificity and accuracy were compared using the Mann-Whitney and Kruskal-Wallis tests (α = 0.05). Changes in amperage and voxel size did not affect the detection of VRFs (p ⟩ 0.05). The VRF detection accuracy was the highest in fibreglass and the lowest in nickel-chromium group. Changes in amperage and voxel size within assessed values do not seem to influence the detection of VRF whereas different intracanal post-materials have significant effect on VRF detection.

Prevalence of permanent numeric dental anomalies in panoramic radiography in an Iranian population

Aim: Dental number anomalies are a group of congenital developmental disorders divided into two groups supernumerary and missing teeth. This study was conducted to investigate the prevalence of numeric dental anomalies using panoramic images in patients referred to the Hamadan Dental Faculty. Methods: In this cross-sectional study, 2,197 panoramic radiographs of patients aged 6-49 years were evaluated. These anomalies are divided into two groups: 1) Supernumerary teeth, including Mesiodens, Distodens, and Peridens, and 2) Missing teeth, including Hypodontia, Oligodontia, and Anodontia. A Chi-square test was performed to assess the relationship between the anomalies. Data analysis was performed using SPSS 16, in which P-value < 0.05 was considered the statistical significance level. Results: Of 736 males (32.2%) and 1548 females (67.8%) in this study, 32 (4.3%) and 55 cases (3.8%) had supernumerary teeth, respectively. The prevalence of supernumerary teeth was 0.3%, 0.5%, and 0.6% in males and 0.2%, 1% and 1.2% in females for mesiodens, distodens, and peridens, respectively. Also, 243 males (10.6%) and 655 females (28.6%) had missing teeth anomalies. Hypodontia in the maxilla was the most common anomaly in both genders, while mesiodens was the least common. Conclusion: Hypodontia was the most common anomaly, followed by peridens; the least common anomaly was mesiodens. The prevalence of supernumerary teeth was greater in males, though the difference was not statistically significant. In comparison, females had a greater prevalence of missing teeth

Comparison of the amount of artifacts induced by zirconium and titanium implants in cone-beam computed tomography images.

BACKGROUND: This study aimed to compare the amount of artifacts induced by the titanium and zirconium implants on cone-beam computed tomography (CBCT) and assess the effect of different exposure settings on the image quality for both materials. METHODS: In this experimental study, 30 zirconium and 30 titanium implants were placed in bovine rib bone blocks. CBCT images were taken in two different fields of view (FOV: 4 × 6 cm2 and 6 × 8 cm2) and at two resolutions (133 µ and 200 µ voxel size). Subsequently, two observers assessed the images and detected the amount of artifacts around the implants through gray values. Data were analyzed by paired t test and independent t test using SPSS 21 and the 0.05 significance level. RESULTS: The results showed that titanium implants caused lower amounts of artifacts than zirconium implants, which was statistically significant (P < 0.001). The larger FOV (6 × 8 cm2) resulted in a lower amount of artifacts in both groups, although the results were only statistically significant in the zirconium group (P < 0.001). The amount of artifacts was increased when using the 133 µ voxel size in both groups, which was only significant in the zirconium group (P < 0.001). CONCLUSION: Our results suggest that zirconium implants induce higher amounts of artifacts than titanium ones. We also concluded that the artifacts could be minimized using the larger FOV and voxel size.

3D-printed bi-layered polymer/hydrogel construct for interfacial tissue regeneration in a canine model.

OBJECTIVES: There are complications in applying regenerative strategies at the interface of hard and soft tissues due to the limited designs of constructs that can accommodate different cell types in different sites. The problem originates from the challenges in the adhesion of dissimilar materials, such as polymers and hydrogels, that can be suitable for regenerating different tissues such as bone and soft tissues. This paper presents a design of a new hybrid construct in which a polymer (polycaprolactone (PCL)) membrane firmly adheres to a layer of hydrogen (gelatin). METHODS: PCL membranes with defined size and porosity were fabricated using 3D printing. The gelatin layer was attached to the PCL membranes using the aminolysis procedure. We have examined this construct for the application of Guided Bone Regeneration (GBR) as a typical surgical regenerative procedure of the oral cavity at the interface of bone and soft tissue. Complete in vitro and in vivo investigations on canine tibia bone defects have been performed. Histological analyses for fibrosis morphometric and bone morphometric evaluation, as well as bone-fibrosis histological grading and CBCT imaging, were conducted. RESULTS: Chemical and morphological studies of the membrane proved that gelatin was uniformly attached to the aminolyzed PCL membranes. The in vitro and in vivo studies indicated the membrane's biocompatibility, mechanical stability, and barrier function for the GBR application. Furthermore, in vitro study showed that the membranes could improve osteogenesis and the regeneration of bone defects. The results illustrated that the mean bone density in the membrane groups was about three times more than that of the control group. SIGNIFICANCE: The fabricated 3D-printed hybrid Gelatin/PCL bi-layered membrane can be a good candidate for interfacial tissue engineering and a promising membrane for GBR procedure.

Complementarity of surgical therapy, photobiomodulation, A-PRF and L-PRF for management of medication-related osteonecrosis of the jaw (MRONJ): an animal study.

BACKGROUND: This study aimed to evaluate the complementarity of surgical therapy, photobiomodulation (PBM), advanced platelet-rich fibrin (A-PRF), and Leukocyte and platelet-rich fibrin (L-PRF) for the management of medication-related osteonecrosis of the jaw (MRONJ). METHODS: Sixty rats underwent injection of zoledronate followed by left mandibular first and second molar extractions to induce MRONJ lesions. All rats were examined for the signs of MRONJ 8 weeks post-dental extraction. Forty-nine rats with positive signs of MRONJ were appointed to seven different groups as follows: control (Ctrl); surgery alone (Surg); surgery and PBM (Surg + PBM); surgery and A-PRF insertion (Surg + APRF); surgery and L-PRF insertion (Surg + LPRF); surgery, A-PRF insertion, and PBM (Surg + APRF + PBM); surgery, L-PRF insertion, and PBM (Surg + LPRF + PBM). Euthanasia was carried out 30 days after the last treatment session. The lesions' healing was evaluated clinically, histologically, and radiographically. Data were analyzed using STATA software version 14, and the statistical significance level was set at 5% for all cases. RESULTS: According to the present study, A-PRF and L-PRF treatment resulted in significant improvements in clinical, histological, and radiographical parameters compared to the Ctrl group (P < 0.05). The PBM also decreased wound dimensions and the number of empty lacunae compared to the Ctrl group (P < 0.05). Surg + APRF + PBM and Surg + LPRF + PBM were the only groups that presented a significantly higher mean number of osteocytes (P < 0.05). No significant differences were observed between A-PRF and L-PRF treatment groups (P > 0.05). CONCLUSIONS: Surgical resection followed by applying A-PRF or L-PRF reinforced by PBM showed optimal wound healing and bone regeneration in MRONJ lesions.

Magnetic resonance imaging study of incidental findings in the paranasal sinuses and ostiomeatal complex.

Purpose: This study aimed to assess incidental abnormal findings in the paranasal sinuses and anatomical variations of the ostiomeatal complex (OMC) on magnetic resonance imaging (MRI) scans. Materials and Methods: MRI scans of 616 patients (mean age, 44.0±19.4 years) were evaluated. Prior to obtaining the MRI scans, a checklist of patients' clinical symptoms was filled out after obtaining their consent. The Lund-Mackay classification was used to assess the paranasal sinuses and OMC. The prevalence of abnormal findings and their associations with patients' age, sex, and subjective symptoms were analyzed by the chi-square test, independent-sample t-test, and analysis of variance. The level of significance was set at 0.05. Results: Abnormal findings in the paranasal sinuses were detected in 32.0% of patients, with a significantly higher prevalence in males (P<0.05), but no significant association with age (P>0.05). Epithelial thickening and retention cyst were the most common abnormal findings in the paranasal sinuses. According to the Lund-Mackay classification, 93% of the study population had normal sinuses (score<4). Concha bullosa and paradoxical concha were detected in 15.3% and 3.4%, respectively, with no significant association with the presence of septal deviation or Lund-Mackay classification (P>0.05). Conclusion: Considering the relatively high prevalence of abnormal findings in the paranasal sinuses, it appears that clinical symptoms alone are not sufficient to diagnose sinusitis. A more accurate strategy would be to assess radiographic images of the paranasal sinuses and use a classification system. Sinusitis should be suspected in patients receiving a high score in this classification.

In vivo efficacy of 3D-printed elastin-gelatin-hyaluronic acid scaffolds for regeneration of nasal septal cartilage defects.

Nasal septal cartilage perforations occur due to the different pathologies. Limited healing ability of cartilage results in remaining defects and further complications. This study sought to assess the efficacy of elastin-gelatin-hyaluronic acid (EGH) scaffolds for regeneration of nasal septal cartilage defects in rabbits. Defects (4 × 7 mm) were created in the nasal septal cartilage of 24 New Zealand rabbits. They were randomly divided into four groups: Group 1 was the control group with no further intervention, Group 2 received EGH scaffolds implanted in the defects, Group 3 received EGH scaffolds seeded with autologous auricular chondrocytes implanted in the defects, and Group 4 received EGH scaffolds seeded with homologous auricular chondrocytes implanted in the defects. After a 4-month healing period, computed tomography (CT) and magnetic resonance imaging (MRI) scans were obtained from the nasal septal cartilage, followed by histological evaluations of new tissue formation. Maximum regeneration occurred in Group 2, according to CT, and Group 3, according to both T1 and T2 images with 7.68 ± 1.36, 5.44 ± 2.41, and 8.72 ± 3.02 mm2 defect area respectively after healing. The difference in the defect size was statistically significant after healing between the experimental groups. Group 3 showed significantly greater regeneration according to CT scans and T1 and T2 images. The neocartilage formed over the underlying old cartilage with no distinct margin in histological evaluation. The EGH scaffolds have the capability of regeneration of nasal cartilage defects and are able to integrate with the existing cartilage; yet, they present the best results when pre-seeded with autologous chondrocytes.

Cone-beam computed tomographic analysis of apical transportation and centering ratio of ProTaper and XP-endo Shaper NiTi rotary systems in curved canals: an in vitro study.

BACKGROUND: Cleaning and shaping of the root canal system is an important step of endodontic treatment. Canal transportation is a common procedural error in preparation of curved canals. This study aimed to compare the canal transportation and centering ratio of two rotary files in curved canals using cone-beam computed tomography (CBCT). METHODS: Forty-four extracted human mandibular first molars with mature apices and 10° to 30° apical curvature were selected. The samples were randomly divided into two groups (n = 22) with similar curvature. The canals were prepared with ProTaper and XP-endo Shaper file systems according to the manufacturers' instructions. The CBCT images were obtained using Cranex 3D CBCT scanner before and after root canal preparation, and canal transportation and centering ratio of the files at 3, 4 and 5 mm levels from the apex were calculated. Data were compared between the two groups using independent t-test at 0.05 level of significance. RESULTS: The ProTaper Universal caused greater canal transportation and had lower centering ratio than XP-endo Shaper in both mesiodistal and buccolingual directions at all levels from the apex. The difference between the two groups regarding canal transportation was significant at all levels from the apex in buccolingual direction (P < 0.05) except for 3 mm from the apex (P > 0.05). The difference between the two groups regarding centering ratio was not significant (P > 0.05) in mesiodistal direction at all levels except for 4 mm from the apex (P < 0.05). CONCLUSION: The ProTaper Universal causes greater canal transportation in both buccolingual and mesiodistal directions than XP-endo Shaper.

Accuracy of maxillofacial prototypes fabricated by different 3-dimensional printing technologies using multi-slice and cone-beam computed tomography.

PURPOSE: This study aimed to compare the accuracy of 3-dimensional (3D) printed models derived from multidetector computed tomography (MDCT) and cone-beam computed tomography (CBCT) systems with different fields of view (FOVs). MATERIALS AND METHODS: Five human dry mandibles were used to assess the accuracy of reconstructions of anatomical landmarks, bone defects, and intra-socket dimensions by 3D printers. The measurements were made on dry mandibles using a digital caliper (gold standard). The mandibles then underwent MDCT imaging. In addition, CBCT images were obtained using Cranex 3D and NewTom 3G scanners with 2 different FOVs. The images were transferred to two 3D printers, and the digital light processing (DLP) and fused deposition modeling (FDM) techniques were used to fabricate the 3D models, respectively. The same measurements were also made on the fabricated prototypes. The values measured on the 3D models were compared with the actual values, and the differences were analyzed using the paired t-test. RESULTS: The landmarks measured on prototypes fabricated using the FDM and DLP techniques based on all 4 imaging systems showed differences from the gold standard. No significant differences were noted between the FDM and DLP techniques. CONCLUSION: The 3D printers were reliable systems for maxillofacial reconstruction. In this study, scanners with smaller voxels had the highest precision, and the DLP printer showed higher accuracy in reconstructing the maxillofacial landmarks. It seemed that 3D reconstructions of the anterior region were overestimated, while the reconstructions of intra-socket dimensions and implant holes were slightly underestimated.

Upper Airway Changes Following Different Orthognathic Surgeries, Evaluated by Cone Beam Computed Tomography: A Systematic Review and Meta-analysis.

PURPOSE: This study sought to assess the upper airway changes following different orthognathic surgeries using cone-beam computed tomography. METHODS: An electronic search of the literature was conducted in major electronic databases including Medline (PubMed), Web of Science, Scopus, and Open Grey for articles published up to January 20, 2018. Human studies that evaluated the changes in the volume and minimum cross-sectional area of the upper airway or its subdivisions in patients who had undergone orthognathic surgery by use of cone-beam computed tomography were included. Manual search of the bibliographies of the included articles was also conducted. The included studies underwent risk of bias assessment. RESULTS: A total of 1330 articles were retrieved. After excluding the duplicates and irrelevant articles, 41 studies fulfilled the eligibility criteria for this systematic review; out of which, 30 entered the meta-analysis. The majority of studies had a medium risk of bias. Mandibular setback, and maxillary advancement + mandibular setback decreased the volume of the upper airway (-6042.87 mm3 and -1498.78 mm3, respectively) and all its subdivisions in long-term (>3 months), except for the nasopharynx, the volume of which increased following maxillary advancement + mandibular setback. Mandibular advancement and maxillomandibular advancement both increased the upper airway volume in long-term (7559.38 mm3 and 7967.06 mm3, respectively); however, only the changes after the former procedure were significant. The minimum cross-sectional area increased after maxillomandibular advancement (161.43 mm2), and decreased following maxillary advancement + mandibular setback (-23.79 mm2) in long-term. CONCLUSION: There is moderate evidence to suggest that mandibular advancement is the only orthognathic movement that provides a statistically significant change in long-term upper airway volume.

Comparison of Biofeedback and Combined Interventions on Athlete's Performance.

The aim of this study was the comparison of neurofeedback and biofeedback as a combination, against biofeedback intervention alone on athletic performance. 45 novice basketball players were allocated into three groups and assigned accordingly, two experimental and one control group. The experimental group 1 received 24 biofeedback sessions only, experimental group 2 received 24 biofeedback and neurofeedback sessions combined, whereas the control group didn't receive any form of intervention. Athletic performance scales were used before and after each intervention and multivariate analysis of covariance was used to compare the two groups. Results showed that in comparison to the control group, the athletic performance scales scores in both experimental groups were significantly increased. Furthermore, in experimental group 2 (combined method), we noticed a significantly greater improvement in performance levels than experimental group 1. We concluded that neurofeedback and biofeedback interventions combined, can be used as an effective method to enhance athletic performance.

Assessment of the accuracy of laser-scanned models and 3-dimensional rendered cone-beam computed tomographic images compared to digital caliper measurements on plaster casts.

PURPOSE: This study investigated the accuracy of laser-scanned models and 3-dimensional (3D) rendered cone-beam computed tomography (CBCT) compared to the gold standard (plaster casts) for linear measurements on dental arches. MATERIALS AND METHODS: CBCT scans and plaster models from 30 patients were retrieved. Plaster models were scanned by an Emerald laser scanner (Planmeca, Helsinki, Finland). Sixteen different measurements, encompassing the mesiodistal width of teeth and both arches' length and width, were calculated using various landmarks. Linear measurements were made on laser-scanned models using Autodesk Meshmixer software v. 3.0 (Autodesk, Mill Valley, CA, USA), on 3D-rendered CBCT models using OnDemand 3D v. 1.0 (Cybermed, Seoul, Korea) and on plaster casts by a digital caliper. Descriptive statistics, the paired t-test, and intra- and inter-class correlation coefficients were used to analyze the data. RESULTS: There were statistically significant differences between some measurements on plaster casts and laser-scanned or 3D-rendered CBCT models (P<0.05). Molar mesiodistal width and mandibular anterior arch width deviated significantly different from the gold standard in both methods. The largest mean differences of laser-scanned and 3D-rendered CBCT models compared to the gold standard were 0.12±0.23 mm and 0.42±0.53 mm, respectively. Most of the mean differences were not clinically significant. The intra- and inter-class correlation results were acceptable for all measurements (>0.830) and between observers (>0.801). CONCLUSION: The 3D-rendered CBCT images and laser-scanned models were useful and accurate alternatives to conventional plaster models. They could be used for clinical purposes in orthodontics and prostheses.

Sex determination by osteometric assessment of the mastoid process using Cone Beam Computed Tomography / Determinação do sexo em uma população Iraniana por avaliação osteométrica do processo mastóide em imagens de TCFC

Objective: Sex determination is one of the most important parameters to identify in forensic science. Because the mastoid process is the most resistant to damage due to its position in the skull base, it can be used for sex determination. The purpose of this study was to measure the dimensions and convexity and internal angles of the mastoid process to present a model of sex determination in Iranian population. Material and methods: This study was performed on three-dimensional images of 190 Cone Beam Computed Tomography (CBCT) of 105 women and 85 men. On each CBCT the distance between the porion and the mastoid (PM), mastoid length (ML), the distance between the mastoidale and the mastoid incision (M-I), the mastoid height (MH), the mastoid width (MW), intermastoidale distance (IMD) the lateral surfaces of the left and right mastoids (IMLSD) and the Mastoid medial convergence angle (MMCA) was measured on both the right and the left. The data were analyzed by descriptive statistics, t-test, and discriminant function analysis. Results: Significant differences were found for all variables except MMCA and MF in both sex. All measured variables except MW were greater for men than women. The discriminant model achieved a total accuracy of 93.7%. Among the measured factors IMD and IMSLD had the most influence on sex determination. Conclusion: Measuring the dimensions of the mastoid process is a very good method for sex determination with high accuracy of 90% (AU)

Objetivo: A determinação do sexo é um dos parâmetros mais importantes para identificação na ciência forense. Por ser o processo mastóide resistente a danos, devido a sua posição na base do crânio, este poderia ser usado na determinação do sexo. O objetivo deste estudo foi mensurar as dimensões, convexidade e ângulos internos do processo mastóide para apresentar um modelo de determinação do sexo em uma população Iraniana. Material e métodos: Este estudo foi realizado em 190 imagens de tomografia computadorizada de feixe cônico (TCFC), sendo 105 mulheres e 85 homens. Em cada TCFC foram realizadas medidas no processo mastóide em comprimento (ML), altura (MH), largura (MW) em ambos os lados direito e esquerdo, também foi medida a distância entre o Pórion e o processo mastóide (PM), distância até incisura mastoidea (M-I), distância entre as superfícies mediais (IMD) distância entre as superfícies laterais dos processos direito e esquerdo (IMLSD) e o ângulo de convergência medial (MMCA). Os dados foram analisados por estatística descritiva, teste t e análise de função discriminante. Resultados: Diferenças significativas foram encontradas para todas as variáveis, exceto MMCA e MF em ambos os sexos. Todas as variáveis medidas, exceto MW, foram maiores para os homens do que para as mulheres. O modelo de análise de função discriminante alcançou uma precisão total de 93,7%. Entre os fatores medidos, o IMD e o IMSLD tiveram a maior influência na determinação do sexo. Conclusão: Podemos concluir que as dimensões do processo mastóide constituem um método para determinação do sexo, em população Iraniana, com precisão de 90% (AU)