Bone Morphogenetic Protein 2 Plus Leukocyte and Platelet-Rich Fibrin for the Treatment of MRONJ.

Leukocyte and platelet-rich fibrin is known to contain high concentrations of growth factors and when associated with rhBMP-2, it may increase bone remodeling due to its osteoinductive property. The aim of this case is to report the outcome of surgical treatment of medication-related osteonecrosis of the jaw with prototype plate installation and the use of leukocyte and platelet-rich fibrin in association with rhBMP-2 in a 78-year-old female patient under therapy with alendronate. The present Studies describes that the combination of this treatment presented complete healing of osteonecrosis and represents a promising treatment option to be used for medication-related osteonecrosis of the jaw.

Double mandible coronoid process: a very unusual feature.

PURPOSE: The double coronoid process (DCP) is a very unusual feature in patient. The literature, which briefly describes just only one case. Being this a very unusual feature, the aim of the paper is to describe the finding, discuss the anatomic, radiological, and clinical characteristics of a DCP. METHODS: A 61-year-old-woman with no significant medical history, extraoral and intraoral examination was unremarkable. Following panoramic radiography (PR) for assessment of periodontal support and pre-implant planning suspicious radiopaque area in the mandibular notch on the left side was observed. Cone-Beam Computed Tomography (CBCT) and Magnetic resonance imaging (MRI) were subsequently performed. RESULTS: No signs and symptoms of syndromes or medical records with a relevant contribution to the DCP existence and the patient denied any type of facial trauma. CBCT image showed the structure found on the PR was indeed a DCP and it was not superimposed on the mandibular notch area, MRI was performed to investigate soft tissue components and temporomandibular joint (TMJ) or other alterations. CONCLUSION: DPC is extremely rare with the only case reported in the literature within the same comparison parameters. In this case images revealed the muscles, articular surfaces and articular disc were well preserved, and no other alterations were found.

A Comparative Study of Multidetector Computed Tomography, Cone Beam Computed Tomography, and Computed Microtomography on Trabecular Bone Structures in the Human Mandible: An Ex Vivo Study.

OBJECTIVE: The aim of this study was to evaluate the accuracy of multislice computed tomography (MSCT) and cone beam computed tomography (CBCT) scanners in the assessment of trabecular bone microarchitecture by radiomorphometric analysis. METHODS: Eight dry human hemimandibles were selected and scanned by 4- and 128-MSCT, CBCT with different voxel sizes, and a computed microtomography (micro-CT). The images were spatially aligned, the axial slices were segmented using CTAn software (Skyscan, Konitch, Belgium), and 10 bone morphometric parameters were quantified. The micro-CT images were the criterion standard. RESULTS: The results show the superiority of CBCT images with 0.2-mm voxel size and 128-MSCT. CONCLUSIONS: We can conclude that the CBCT scanner with 0.2-mm voxel size and 128-MSCT had better performance on reproducibility of the distribution and organization of trabecular bone and marrow spaces evaluated in this study.

Reliability and accuracy of automatic segmentation of mandibular 3D models on linear measurements.

OBJECTIVE: Evaluate if automatic segmentation of mandibular three-dimensional (3D) models is reliable and accurate. MATERIALS AND METHODS: Eight dry mandibles with eight silica markers were scanned in the i-CAT Classic device (Imaging Sciences International). Automatic segmentation was performed using nine standard preset thresholds in the Dolphin software (Dolphin Imaging & Management Solutions). Three observers individually made twice eight linear measurements on the mandibular 3D models. Another observer made physical measurements, twice as well, on the dry mandibles. Reliability and accuracy were evaluated with intraclass correlation coefficients (ICCs), Dahlberg's formula, Bland-Altman analyses, and changing bias with regression analyses. RESULTS: Inter-observer and intra-observer ICCs and Dahlberg's error were ≥ 0.75 and ≤ 1.0 mm, respectively, for all measurements. Inter-observer agreement between mandibular 3D models and physical measurements ranged from -0.37 to 0.91 mm. CONCLUSIONS: Linear measurements made on mandibular 3D models obtained using standard preset thresholds are reliable and accurate. However, additional studies are necessary to confirm this hypothesis for clinical applications. CLINICAL RELEVANCE: Since the 3D models are useful for diagnostics and surgical planning, it is necessary to determinate whether the linear measurements made on 3D models obtained by automatic segmentation are sufficiently reliable and accurate.

Diagnostic accuracy of CBCT compared to panoramic radiography in predicting IAN exposure: a systematic review and meta-analysis.

OBJECTIVES: The aim of this study is to verify whether the diagnostic accuracy of cone beam computed tomography (CBCT) is superior to panoramic radiography (PR) in predicting inferior alveolar nerve (IAN) exposure during the lower third molar extraction. MATERIALS AND METHODS: Eight electronic databases were searched up to September 2020. Studies that evaluated the accuracy (sensitivity, specificity, positive-predictive value, and negative predictive value) of both imaging methods were included. The gold standard was the visualization of the IAN exposure during the extraction of lower third molars. The gray literature was also used to include any other paper that might meet the eligibility criteria. The meta-analysis was performed with OpenMeta-Analyst and ReviewManager v.5.3 software. The methodology of the studies was evaluated using QUADAS-2. RESULTS: Among the search, three studies met all the eligibility criteria and were included in the qualitative and quantitative synthesis. The meta-analysis was conducted with all included studies. Accuracy values for CBCT were 95.1% for sensitivity (p=0.666) and 64.4% for specificity (p<0.001). For PR sensitivity and specificity, we observed 73.9% (p=0.101) and 24.8% (p<0.001), respectively. CONCLUSIONS: Both exams were reliable for detecting positive cases of exposure of the IAN. However, CBCT had a better performance compared to PT in predicting IAN exposure during surgery. CLINICAL RELEVANCE: To better understand the CBCT accuracy in predicting the IAN exposure during surgery, since this event can increase the likelihood of IAN injury and, consequently, cause neurosensory disturbances.

CBCT does not reduce neurosensory disturbances after third molar removal compared to panoramic radiography: a systematic review and meta-analysis.

OBJECTIVES: The current dentistry scenario is showing an increase in the availability of cone-beam computed tomography (CBCT) in dental offices. Oral surgeons are using three-dimensional information as an additional tool to assess preoperative data for lower third molar (LTM) removal in moderate and high-risk cases of inferior alveolar nerve (IAN) injury diagnosed through the panoramic radiography (PR). The aim of this study is to identify whether CBCT examination reduces neurosensoric disturbances (ND) following the removal of the LTM when compared to PR. MATERIALS AND METHODS: PubMed, Embase, Web of Science, Science Direct, and Scopus electronic databases were searched for studies published up to February 2019. The gray literature was also searched including papers that eventually met the eligibility criteria. Meta-analysis was performed using the comprehensive meta-analysis software, p < 0.05 considered significant. RESULTS: Among the search, 6 studies met all eligibility criteria. There was no statistically significant difference between the two groups (PR and CBCT) in all six studies regarding reducing ND (95%. Confidence interval, 0,788-1734; heterogeneity: Q = 10,361; I2 = 22.788%). CONCLUSIONS: CBCT was not superior to PR in avoiding ND. However, further studies are necessary with standardized parameters for a better comparability between variables in the studies. CLINICAL RELEVANCE: To better understand the CBCT clinical applicability in LTM removal to avoid unnecessary extra radiation when compared to PR to the patient and to improve patient's prognosis.

Zoledronic Acid Induces Site-Specific Structural Changes and Decreases Vascular Area in the Alveolar Bone.

PURPOSE: The aim was to assess the effect of a relevant regimen of zoledronic acid (ZA) treatment for the study of bisphosphonate-related osteonecrosis of the jaw on alveolar bone microstructure and vasculature. A sub-objective was to use 3-dimensional imaging to describe site-specific changes induced by ZA in the alveolar bone. MATERIALS AND METHODS: Five Wistar rats received ZA (0.6 mg/kg) and five (controls) received saline solution in the same volume. The compounds were administered intraperitoneally in 5 doses every 28 days. The rats were euthanized 150 days after therapy onset. The mandibles were scanned using high-resolution (14-µm) micro-computed tomography (micro-CT), decalcified, cut into slices for histologic analysis (5 µm), and stained with hematoxylin-eosin. Bone quality parameters were calculated using CT-Analyser software (Bruker, Kontich, Belgium) in 2 different volumes of interest (VOIs): the region between the first molar roots (VOI-1) and the periapical region under the first and second molars' apex (VOI-2). Blood vessel density and bone histomorphometric parameters were calculated only for the region between the roots of the first molar using AxioVision Imaging software (version 4.8; Carl Zeiss, Gottingen, Germany). RESULTS: ZA-treated rats showed a significant increase in percentage of bone volume and density (P < .05), with thicker and more connected trabeculae. Furthermore, the ZA group showed a significant decrease in the size of the marrow spaces and nutritive canals and in blood vessel density (P < .05). In the micro-CT evaluation, VOI-2 showed better outcomes in measuring the effect of ZA on alveolar bone. CONCLUSIONS: ZA treatment induced bone corticalization and decreased alveolar bone vascularization. VOI-2 should be preferred for micro-CT evaluation of the effect of bisphosphonates on alveolar bone. This analysis allowed the effect of ZA on alveolar bone and its vascularization to be characterized. The results of this analysis may add further knowledge to the understanding of the physiopathology of osteonecrosis of the jaw.

Analysis of linear measurements on 3D surface models using CBCT data segmentation obtained by automatic standard pre-set thresholds in two segmentation software programs: an in vitro study.

OBJECTIVE: The aim of this in vitro study was to evaluate the reliability and accuracy of linear measurements on three-dimensional (3D) surface models obtained by standard pre-set thresholds in two segmentation software programs. MATERIALS AND METHODS: Ten mandibles with 17 silica markers were scanned for 0.3-mm voxels in the i-CAT Classic (Imaging Sciences International, Hatfield, PA, USA). Twenty linear measurements were carried out by two observers two times on the 3D surface models: the Dolphin Imaging 11.5 (Dolphin Imaging & Management Solutions, Chatsworth, CA, USA), using two filters(Translucent and Solid-1), and in the InVesalius 3.0.0 (Centre for Information Technology Renato Archer, Campinas, SP, Brazil). The physical measurements were made by another observer two times using a digital caliper on the dry mandibles. RESULTS: Excellent intra- and inter-observer reliability for the markers, physical measurements, and 3D surface models were found (intra-class correlation coefficient (ICC) and Pearson's r ≥ 0.91). The linear measurements on 3D surface models by Dolphin and InVesalius software programs were accurate (Dolphin Solid-1 > InVesalius > Dolphin Translucent). The highest absolute and percentage errors were obtained for the variable R1-R1 (1.37 mm) and MF-AC (2.53 %) in the Dolphin Translucent and InVesalius software, respectively. CONCLUSION: Linear measurements on 3D surface models obtained by standard pre-set thresholds in the Dolphin and InVesalius software programs are reliable and accurate compared with physical measurements. CLINICAL RELEVANCE: Studies that evaluate the reliability and accuracy of the 3D models are necessary to ensure error predictability and to establish diagnosis, treatment plan, and prognosis in a more realistic way.

Evaluation of Interforaminal Mandible Region of Individuals With Pierre Robin Sequence and Treacher Collins Syndrome Through the Cone-Beam Computed Tomography.

The Pierre Robin sequence (PRS) and the Treacher Collins syndrome (TCS) are conditions that cause significant abnormalities of jaw. This study was conducted in anticipation of evaluating the morphology of interforaminal region and identify the anatomic variations: anterior loop and mandibular incisive canal, in individuals with PRS and TCS by cone-beam computed tomography and compare them with individuals without craniofacial anomalies. By applying the t-test, the results showed no statistically significant difference, allowing to infer that there are no significant differences in interforaminal mandible morphology between groups and indicated that the prevalence and location of the studied anatomic variations are consistent with those described in literature.

Mandibular ramus length as an indicator of chronological age and sex.

Age and sex estimation is crucial in forensic investigations, whether in legal situations that involve living people or to identify mortal remains. The aim of this study was to establish reference values in a Brazilian population to estimate age and sex by measuring the length of the mandibular ramus on lateral cephalometric radiographs, and to determine the probability that an individual being is 18 years or older, based on the results that were obtained. Two hundred and eighteen scanned lateral cephalograms of individuals between 6 and 20 years of age (101 males and 117 females) were measured with reference to mandibular ramus length (the distance between Condylion superior (Cs) and Gonion (Go)) using ImageJ 1.41 software (NIH, Bethesda, MA, USA). The results showed that sexual dimorphism was not observed until 16 years and, based on the ramus length measurements in this sample, it is possible to predict sex with an accuracy of only 54 %. There was a positive correlation between age and ramus length (r = 0.90; p < 0.001). From the linear regression analysis, one formula was derived; therefore, it was possible to calculate the individual's age, given his or her ramus length. The results showed that if an individual's ramus length is 7.0 cm or more, then there is an 81.25 % chance that the individual is 18 years old or older. In conclusion, the mandibular ramus length was not effective in discriminating sex. Mandibular length is strongly related to chronological age and can be used to predict whether an individual is 18 years or older with high degree of expected accuracy.

Accessory mental foramina: prevalence, position and diameter assessed by cone-beam computed tomography and digital panoramic radiographs.

OBJECTIVE: To investigate the presentation of accessory mental foramina (AMF) on cone-beam computed tomography (CBCT) and digital panoramic examinations (PAN). STUDY DESIGN: Imaging examinations (i.e., CBCT and PAN) of 100 patients (200 hemi-mandibles) were assessed. AMF prevalence, diameter, and location related to adjacent teeth and to the mental foramen (MF) were analyzed. RESULTS: On CBCT images, the AMF was observed in 3% of the patients: two unilateral cases and one bilateral case, with mean diameter of 0.93 mm (±0.3); no AMF was identified on PAN. Most AMF were located between the premolars, either superiorly (two cases) or mesially (two cases) to the MF. The mean horizontal distance to the corresponding MF was 2.3 mm (±1.0) and the mean vertical distance was 4.0 mm (±0.7). CONCLUSIONS: The results of this study suggest that CBCT is an effective tool for presurgical tridimensional assessment of the neurovascular structures, such as MF and its variations; On the other hand, PAN examinations were not able to show the AMF cases assessed on CBCT.

Presurgical CBCT assessment of maxillary neurovascularization in relation to maxillary sinus augmentation procedures and posterior implant placement.

PURPOSE: To provide more information to clinicians planning sinus grafting and maxillofacial surgical interventions, the present study evaluated the prevalence, diameter and location of the superior alveolar canals (SAC) using CBCT images. METHODS: The maxillary sinus CBCT scans (i-CAT Classic(®), ISI, USA) of 100 adult patients (67 women and 33 men) aged 20-79 years [mean (SD) 40 (15)] were examined. A dentomaxillofacial radiologist observed the SAC based on CBCT image data and more specifically the parasagittal views to assess SAC's diameter and location. RESULTS: The anterior and posterior SAC, double ASAC, intraosseous anastomoses and the extension of the anterior SAC to the piriform aperture were observed in 100, 73, 24.5, 38.5 and 84 % of the cases, respectively. The anastomosis was located between canine and first premolar in 43 % of the cases. The SAC diameters were in 80 % of the cases ≤1 mm, remaining canals had a diameter between 1 and 2 mm. The distance of the SAC to the alveolar crest ranged between 2.42 and 44.6 mm. The anterior SAC was more prevalent in the upper (53 %) and middle (44 %) thirds of the maxillary sinus, while the posterior SAC was more prevalent in the middle (36 %) and lower thirds (64 %). The distance was significantly bigger in men in some tooth positions. CONCLUSIONS: Based on the present findings, one-fifth of the patients may have a diameter of the SAC >1 mm, large enough to cause bleeding and/or paraesthesia. CBCT imaging may assist surgeons to plan grafting and osteotomy procedures, while avoiding these neurovascular structures.

A Systematic Review on Caries Detection, Classification, and Segmentation from X-Ray Images: Methods, Datasets, Evaluation, and Open Opportunities.

Dental caries occurs from the interaction between oral bacteria and sugars, generating acids that damage teeth over time. The importance of X-ray images for detecting oral problems is undeniable in dentistry. With technological advances, it is feasible to identify these lesions using techniques such as deep learning, machine learning, and image processing. Therefore, the survey and systematization of these methods are essential to determining the main computational approaches for identifying caries in X-ray images. In this systematic review, we investigated the primary computational methods used for classifying, detecting, and segmenting caries in X-ray images. Following the PRISMA methodology, we selected relevant studies and analyzed their methods, strengths, limitations, imaging modalities, evaluation metrics, datasets, and classification techniques. The review encompassed 42 studies retrieved from the Science Direct, IEEExplore, ACM Digital, and PubMed databases from the Computer Science and Health areas. The results indicate that 12% of the included articles utilized public datasets, with deep learning being the predominant approach, accounting for 69% of the studies. The majority of these studies (76%) focused on classifying dental caries, either in binary or multiclass classification. Panoramic imaging was the most commonly used radiographic modality, representing 29% of the cases studied. Overall, our systematic review provides a comprehensive overview of the computational methods employed in identifying caries in radiographic images and highlights trends, patterns, and challenges in this research field.

CBCT vs panoramic radiography in assessment of impacted upper canine and root resorption of the adjacent teeth: A systematic review and meta-analysis.

Background: The IC may cause reabsorption of adjacent teeth; therefore detailed assessment of its position would enhance decision-making in the clinical workflow. The objective was to compare cone-beam computed tomography (CBCT) and panoramic radiography (PR) in assessing the position of the impacted upper canine (IC) and root resorption of adjacent teeth. Material and Methods: Pubmed, EMBASE, Science Direct, Web of Science, and SCOPUS databases were searched for studies published before August 2023. Studies that evaluated IC by using both imaging methods were included. For statistical analysis, the Comprehensive Meta-Analysis software (Biostat; Englewood, NJ) was used, p≤0.05. Results: A total of 17 articles were included, with 877 patients (average age of 17.6 years) and 1,115 ICs. The most frequent mesio-distal location of the IC was in sectors 3 and 4. The meta-analysis was performed with eleven studies. CBCT was more accurate in determining the labio-palatal position compared with PR (p<0.001) (CI 95%; 60% in labial position, 0.254-0.542, OR:0.398; 56% in palatal position, 0.350-0.533, OR:0.441; 78% in mid-alveolus position, 0.188-0.234, OR:0.221). For IC angulation to the midline, CBCT showing a smaller and more accurate angle than PR (p<0.001) (CI 95%, 18.008-33.686). IC angulation to the occlusal plane and lateral incisor, there was smaller angle in PR compared to CBCT (p<0.001) (CI 95%, 51.292-65.934; CI 95%, 30.011-55.954). With PR, fewer cases of root resorption of teeth adjacent to the IC were visualized compared with CBCT (86% less) (p<0.001) (CI 95%, 0.089-0.186; OR value: 0.138; n=1049). Conclusions: CBCT showed statistically significant differences compared to PR in the assessment of IC position and root resorption of adjacent teeth. CBCT provided clinically relevant information that may contribute to diagnosing and planning IC treatment when PR was not sufficient. Key words:Canine teeth, tooth, impacted, panoramic radiography, Cone-beam computed tomography, systematic review, meta-analysis.

Evaluation of Mandibular Bone Microstructure in CT Scans of People with Sickle Cell Disease.

OBJECTIVE: Sickle cell disease (SCD) is a common inherited disease, and is characterized by a genetic modification that determines the production of a hemoglobin with altered morphology. This anatomical change of hemoglobin leads to vaso-occlusive disorders and premature hemolysis of the cell, causing chronic anemia and bone marrow hyperplasia due to increased hematopoietic demand. As a consequence, several skeletal changes are reported in the skull, spine, ribs, pelvis, femur, and metatarsals. In the craniofacial region, dentofacial deformities are described, especially maxillary protrusion. However, studies evaluating bone microarchitecture are scarce. The aim of this study is to evaluate the mandibular bone microstructure of people with SCD on computed tomography (CT) scans. MATERIALS AND METHODS: Morphometric parameters were analyzed on CT scans of the mandible of people with SCD and people without this disease or any other disease affecting bone metabolism, matched for sex and age. STATISTICAL ANALYSIS: The results were compared by Student's t-test for paired samples and for an error probability of 5%. RESULTS: This study demonstrated that the mandibular bone of people with SCD presents significantly less number, connectivity and thickness of bone trabeculae, as well as having a lower fractal dimension and greater porosity. CONCLUSION: Mandibular bone of people with SCD has lower bone density and more widely spaced trabeculae.

Application of two segmentation protocols during the processing of virtual images in rapid prototyping: ex vivo study with human dry mandibles.

OBJECTIVES: The aim of this study was to evaluate the accuracy of virtual three-dimensional (3D) reconstructions of human dry mandibles, produced from two segmentation protocols ("outline only" and "all-boundary lines"). MATERIALS AND METHODS: Twenty virtual three-dimensional (3D) images were built from computed tomography exam (CT) of 10 dry mandibles, in which linear measurements between anatomical landmarks were obtained and compared to an error probability of 5 %. RESULTS: The results showed no statistically significant difference among the dry mandibles and the virtual 3D reconstructions produced from segmentation protocols tested (p = 0,24). CONCLUSIONS: During the designing of a virtual 3D reconstruction, both "outline only" and "all-boundary lines" segmentation protocols can be used. CLINICAL RELEVANCE: Virtual processing of CT images is the most complex stage during the manufacture of the biomodel. Establishing a better protocol during this phase allows the construction of a biomodel with characteristics that are closer to the original anatomical structures. This is essential to ensure a correct preoperative planning and a suitable treatment.

Position of the greater palatine foramen: an anatomical study through cone beam computed tomography images.

PURPOSE: The block anesthesia of the greater palatine foramen (GPF) is largely used in minor oral surgeries, periodontics and general dentistry. Furthermore, the area of the GPF serves as a donor of soft tissue graft. So, the aim of this study was to evaluate the position and characteristics of the GPF in Brazilian patients using cone beam computed tomography (CBCT) providing anatomical information for the greater palatine nerve block anesthesia and indicate site to collect palatal donor tissue. METHODS: Fifty CBCT exams of Brazilian patients with a mean age of 35.8 years (27 male/23 female) were evaluated. All patients had erupted first, second and third upper molars. A total of 100 GPF were evaluated bilaterally. The GPFs were assessed regarding position, diameter and distances to the midline maxillary suture (MMS) and to alveolar ridge (AR). Guidelines were drawn in the CBCT axial image depicting all molar interproximal surfaces, bilaterally. The guidelines were located between first, second and third molar and in the center of the second and third, performing five guidelines in each side. These guidelines and the molars were landmarks to assess the GPF anatomic position. RESULTS: From the 100 GPF analyzed, 92 were located in the third molar region (24 male/22 female). The 92 GPF were distributed as 47 in the left side and 45 in the right side. The average GPF diameter and the distance to both the AR and the MMS were 3.1 mm; 7.9 and 15.3 mm, respectively. CONCLUSIONS: Within the limits of this study, we concluded that the in Brazilian patients studied, the GPF location was more closely related to third molar. Therefore, whenever the third molar is erupted, it could be used as landmark for successful GPN block anesthesia. Moreover, harvesting palatal mucosa graft around the third molar should be done cautiously to prevent damage to the GPF vascular-nerve complex.

Prevalence of orofacial alterations in patients with sickle-cell disease: Systematic review and meta-analysis.

OBJECTIVE: The aim of this study was to identify the prevalence of orofacial alterations in sickle-cell disease (SCD) and to compare it with the general population. STUDY DESIGN: This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. The search was conducted on PubMed, Embase, Scientific Electronic Library Online, Web of Science, Cochrane Library, gray literature, and references of the included articles. RESULTS: A total of 770 records were found, and 28 studies were selected. In SCD, the prevalence of decreased bone density was 57% (95% CI: 35%-80%), with Q: P < .01 and I2 = 95%; for stepladder pattern was 30% (IC: 13%-47%), Q: P < .01 and I²: 93%; for delayed eruption was 20% (95% CI: 6%-34%), with Q: P < .01 and I2 = 86, Q: P < .01 and I2 = 99%; and for malocclusion, 66% (95% CI: 39%-92%), Q: P < .01 and I2 = 98%. A high risk of bias was observed in relation to the sample size of the studies. A limited number of articles compared the prevalence of orofacial alterations in patients with SCD and healthy individuals. CONCLUSIONS: Decreased bone density, malocclusion, orofacial pain, tooth necrosis, eruption delay, periodontal disease, and neuropathies may be present in patients with SCD with variable prevalence.

Assessment of variations of the mandibular canal through cone beam computed tomography.

The neurovascular bundle may be vulnerable during surgical procedures involving the mandible, especially when anatomical variations are present. Increased demand of implant surgeries, wider availability of three-dimensional exams, and lack of clear definitions in the literature indicate that features of anatomical variations should be revisited. The objective of the study was to evaluate features of anatomical variations related to mandibular canal (MC), such as bifid canals, anterior loop of mental nerve, and corticalization of MC. Additionally, bone trabeculation at the submandibular gland fossa region (SGF) was assessed and related to visibility of MC. Cone beam computed tomography exams from 100 patients (200 hemimandibles) were analyzed and the following parameters were registered: diameter and corticalization of MC; trabeculation in SGF region; presence of bifid MC, position of bifurcations, diameter, and direction of bifid canals; and measurement of anterior loops by two methods. Corticalization of the MC was observed in 59% of hemimandibles. In 23%, MC could be identified despite absence of corticalization. Diameter of MC was between 2.1 and 4 mm for nearly three quarters of the sample. In 80% of the sample trabeculation at the SGF was either decreased or not visible, and such cases showed correlation with absence of MC corticalization. Bifid MC affected 19% of the patients, mostly associated with additional mental foramina. Clinically significant anterior loop (>2 mm of anterior extension) was observed in 22-28%, depending on the method. Our findings, together with previously reported limitations of conventional exams, draw attention to the unpredictability related to anatomical variations in neurovascularization, showing the contribution of individual assessment through different views of three-dimensional imaging prior to surgical procedures in the mandible.

A single session of antimicrobial photodynamic therapy does not influence the alveolar repair process in rats.

The aim of this study was to use microscopic and molecular techniques to evaluate the effects of a single session of antimicrobial photodynamic therapy (aPDT) on the alveolar repair process after tooth extraction in rats. The study sample included 84 rats divided into four groups, as follows: a) Control - untreated socket; b) Laser - socket treated using photobiomodulation; c) TBO - socket treated with topic application of the photosensitizer agent, toluidine blue O (TBO); and d) aPDT - socket treated with TBO and laser irradiation. An additional rat was used for thermal mapping during socket irradiation. The animals were euthanatized at 6, 15, and 28 days after unilateral extraction of the upper incisor. Quantitative and qualitative analyses of the connective and bone tissues, blood clot, blood vessel, and inflammatory infiltrate were performed, and real-time polymerase chain reaction was used to study the expression of genes (collagen type I, osteocalcin, alkaline phosphatase [ALP], runt-related transcription factor 2 [RUNX2], and vascular endothelial growth factor [VEGF]) involved in the bone healing process. No statistically significant differences in microscopic and molecular outcomes were observed between the groups (p > 0.05). A positive correlation was seen to exist between blood clot and VEGF (p = 0.000), and a negative correlation was observed between bone tissue and ALP (p = 0.028) and blood vessel and VEGF (p = 0.018). A single session of aPDT in the dental extraction site did not influence the alveolar repair process in rats.