Injury Risk Estimation in Mandible-Related Surgical Procedures: A CBCT Study Based on Vital Interforaminal Anatomical Structures.

The mandibular interforaminal region has been considered safe for surgical procedures; nevertheless, the risk of injury to neurovascular structures, such as the mental foramen (MF) and its related structures (anterior loop [AL] and lingual foramina [LF]) should not be overlooked. The study aimed to evaluate the relative risk of injury to these structures during surgical procedures in the anterior region of the mandible based on cone-beam computed tomography (CBCT) scans. A retrospective cross-sectional and observational study was performed on 250 CBCTs from adults (18-69 years) with dentate jaws. Linear measurements of the MF, AL, and LF were evaluated to estimate the risk of injury to these structures during chin-related surgical procedures. The most frequent distance between the base of the mandible (BM) and MF was 8 mm (30.2%). In addition, 20.4% of the CTs had 6 mm from the vestibular cortical bone to the LF. The commonly found measurement from LF to the apex of the nearest tooth was 7 mm (24.0%); 64.2% of the CTs showed a 2-mm distance between the most distal point of the dental implant site to the most anterior point of the AL. Safety distances for genioplasty techniques (MF to mandible base > 6 mm, 96.6% [CI 95%, 95.0%-98.2%]) were observed. Considering the 5-mm cut-off point between the lower limit of a hypothetical bone graft and the chin, 65.4% (CI 95%, 58.9%-71.9%) of CTs were within this distance. Regarding the safety margin of 8 mm, 85.6% (CI 95%, 80.8%-90.4%) were up to this value. This study found safety margins for genioplasty and chin bone grafting surgical techniques that adopt a 5-mm cut-off point. Further similar studies assessing other surgical methods and employing larger samples from different geographical origins may contribute to this field of investigation.

Influence of the metal post material, tooth location in the dental arch, and metal artifact reduction tool on vertical root fracture diagnosis in cone beam CT.

This study aimed to evaluate the influence of the metal post composition, tooth location in the dental arch, and metal artifact reduction (MAR) on vertical root fracture (VRF) diagnosis in cone beam computed tomography (CBCT). Twenty-two unirradicular premolars (12 sound and 10 fractured) and two alveolar sockets of a mandible (anterior and posterior regions) composed the sample. CBCT scans of each tooth with a metal post placed into the root canal-silver-palladium (Ag-Pd), cobalt-chromium (Co-Cr), or nickel-chromium (Ni-Cr)-were individually acquired for each mandibular region, and two conditions of MAR, using a OP300 device (Instrumentarium, Finland). Images were assessed by five evaluators independently for VRF detection. Diagnostic values were calculated and compared among all groups using multi-way ANOVA with Tukey post hoc test to investigate the effect of post material, anatomical region, and MAR on VRF diagnosis (α = 0.05). Values of area under the receiver operating curve and specificity were not influenced by the studied factors (p > 0.05). Sensitivity was influenced by the MAR in both mandibular regions (p < 0.05). In the anterior region, sensitivity values increased when the MAR was enabled, regardless of the metal post material (p < 0.05). Similar behavior was noticed in the posterior region for Ni-Cr (p < 0.05) but not for Ag-Pd and Co-Cr posts (p > 0.05). The MAR improved the sensitivity in VRF diagnosis for all tested metal posts in the mandibular anterior region and for the Ni-Cr post in the mandibular posterior region. Therefore, for images obtained in the OP300 CBCT device, activation of the MAR is suggested in these cases.

Computed tomography assessment of maxillary sinus hypoplasia and associated anatomical variations: a systematic review and meta-analysis of global evidence.

OBJECTIVE: To summarize the scientific evidence on the prevalence of maxillary sinus hypoplasia (MSH) and associated anatomical variations as assessed by computed tomography scans. STUDY DESIGN: This PROSPERO-registered systematic review followed the recommendations of the PRISMA guidelines. Search algorithms were constructed for each of the six databases and gray literature. After screening the references (Rayyan®), the extracted data were meta-analyzed according to a random-effects model. The joanna briggs critical appraisal tool assessed the methodological quality of the included studies. The GRADE approach was used to estimate the certainty of the evidence. RESULTS: From a total of 2781 studies screened, 22 were considered for four meta-analysis. The prevalence of MSH in 7358 patients was 5.65% (CI95% = 4.07-7.47%) with significant heterogeneity between studies (p < 0.001, I2 = 89.30%). MSH was identified in 295 patients, of whom 82.38% (CI95% = 75.82-88.09%) had unilateral hypoplasia and 17.62% (CI95% = 11.91-24.18%) bilateral hypoplasia with moderate heterogeneity between studies (p < 0.0503, I2 = 42.87%). The prevalence of MSH in 9998 maxillary sinuses was 3.77% (95% CI = 2.44-5.38%), with significant heterogeneity between studies (p < 0.001, I2 = 92.84%). Hypoplastic/aplastic uncinate process, concha bullosa and paradoxical concha were the most reported anatomical variations. The studies presented a low-moderate methodological quality. The certainty of the evidence was very low to moderate. CONCLUSION: The prevalence of maxillary sinus hypoplasia observed was 5.65%, with most cases being unilateral.

Differential response of fire on the community dynamics of five insect taxa in a tropical mountaintop forest archipelago.

The Earth's most diverse group of organisms is facing an imminent crisis, as recent investigations suggest a remarkable decline in insect diversity. Within this context, altimontane forest islands might emerge as important refuges holding an invaluable diversity of species that would be doomed to disappear. Here, we aimed to examine the impact of fire on the temporal variation of ant, bee, butterfly, dung beetle, and wasp communities in natural and highly threatened altimontane forest islands. We predicted that fire incidence would increase the natural variation in the structure of these insects' communities over time. Furthermore, we predicted that each taxon would respond accordingly to their ability to move between forest islands (i.e., vagility). We sampled these five bioindicator taxa in the rainy seasons of 2014, 2015, 2018, and 2020 within 14 forest islands in southeast Brazil. We assessed the incidence (presence/absence) of fire occurrence on each forest island toward the end of the dry season in each sampling year. We found an influence of fire incidence on the species composition changes over time (temporal ß-diversity) in the less vagile insect groups: ants, and dung beetles. Nevertheless, we found no influence of fire incidence on shifts in species composition of highly vagile insects: bees, butterflies, and wasps. Importantly, species turnover was the primary component of temporal ß-diversity driving the interannual variation of all insect taxa examined in this study. Our results highlight the distinct responses of more-or-less vagile insect groups to fire in forested ecosystems and shed light on the drivers of vulnerability and resilience of these groups to this critical anthropogenic pressure. By understanding and elucidating the intricate responses of distinct insect communities to global stressors, we can strengthen our capacity to predict future trends in biodiversity decline and provide valuable insights for conservation efforts and environmental management strategies.

Factors Associated with Periodontitis in Patients with and without HIV.

Purpose: The aim of this study was to compare clinical periodontal conditions in HIV-positive people on HAART with an HIV-negative group, in addition to investigating factors associated with periodontitis in the entire sample. Methods: This was a cross-sectional study. Data were collected by oral clinical examination for the diagnosis of periodontitis, review of medical records, and application of a questionnaire containing personal data, deleterious habits, and oral hygiene habits for the other variables. The results were analyzed by Pearson's χ 2 test and Student's t-test. A logistic regression model was constructed for the multivariate analysis and periodontitis was defined as a dependent variable. The analysis was performed on the entire sample (HIV+ and HIV-) and also on the group consisting of only people living with HIV. Results: Individuals older than 43 years old and with HIV were more likely to develop moderate and severe periodontitis (47.80 and 4.84 times, respectively). When analyzing only HIV+, in addition to age (OR = 2.795; CI = 1.080-7.233), the use of nonnucleoside reverse transcriptase inhibitors (NNRTIs) (OR = 2.841; CI = 1.135-7.112) was also associated with moderate and severe periodontitis. Conclusion: It was possible to observe a higher prevalence of periodontitis among individuals with HIV, showing an association between the virus, advanced age, and moderate or severe periodontitis.

Can maxillary molar dimensions predict the presence of the second mesiobuccal canal?

OBJECTIVE: To evaluate the potential of maxillary molar dimensions as predictors of the presence of the second mesiobuccal (MB2) canal. METHODS: Micro-computed tomography scans were obtained from 47 maxillary molars, out of which 26 had the MB2 canal. The distance between root canals, extension of the canals, and thickness of surrounding dentin were obtained from axial images at the furcation level, 3 mm from the apex, and 5 mm from the apex. The association between the measurements and the presence of the MB2 canal was assessed using multiple logistic regression and odds ratio. RESULTS: At the furcation level, the bucco-palatal extension of the MB1 canal significantly decreased the chance of the presence of the MB2 canal. Regarding the thickness of surrounding dentin measurements, the mesial and distal aspects of the MB1 canal at 3 mm from the apex were statistically significant to decrease and increase the chance of presence of the MB2 canal, respectively. Regarding the extension of the canals, only buccal-palatal extension seems to decrease the chance of the presence of the MB2 canal. CONCLUSION: The presence of the MB2 canal in the mesiobuccal root of maxillary molars is associated with the bucco-palatal extension and surrounding dentin thickness of the first mesiobuccal canal, and seems to be unrelated to the dimensions of the distobuccal and palatal roots.

Can the detection of second mesiobuccal canals be enhanced based on the volume of adjacent canals?

OBJECTIVES: The purpose of this study was to evaluate whether the presence of the second mesiobuccal (MB2) canal is related to volumetric differences on the adjacent canals of maxillary molars. DESIGN: Forty-seven maxillary first and second molars with and without the MB2 canal were individually scanned using microcomputed tomography (micro-CT). The volume of each canal was measured by an evaluator with experience in micro-CT analysis. The intraclass correlation coefficient (ICC) was obtained. Multiple logistic regression and odds ratio was calculated. To compare the volume of canals in molars with and without MB2, the Mann-Whitney test was applied (α = 0.05). RESULTS: The intra-examiner reproducibility was almost perfect (ICC=0.97). Multiple logistic regression demonstrated that the volume of the mesiobuccal (MB1) canal can possibly act as a predictor of the presence of the MB2 canal. It was also found that the MB1 canal volume is larger in molars without the MB2 canal (p = 0.01). No statistically significant difference was observed in the adjacent canals (p > 0.05). CONCLUSIONS: Despite the challenging detection of the presence of MB2 canals, clinicians should be aware that MB1 canals of reduced volume are highly suggestive of their presence.

Anatomical study of the maxillary sinus: which characteristics can influence its volume?

PURPOSE: To investigate whether there is a relationship between the volume of the maxillary sinus and individual parameters such as gender, side, posterior tooth absence, sinus membrane thickening, bony septa, vertical and sagittal skeletal patterns. METHODS: The tomographic volume of the maxillary sinus from 211 individuals (422 sides) was evaluated using Horos DICOM Viewer Software. Bony septa and sinus membrane thickening were classified as absent or present. At the same time, loss of one or more teeth in the posterior region of the maxilla (except for the third molars) was considered. The t test was applied to analyze maxillary sinus volume according to gender, age, side, posterior tooth absence, sinus membrane thickening and bony septa. A one-way analysis of variance (ANOVA) with Tukey's post-hoc test was applied to compare sagittal and vertical patterns. Pearson's correlation coefficient was also used to verify the association between maxillary sinus volume, age and skeletal patterns. RESULTS: Concerning the sagittal skeletal pattern, a statistically significant difference was observed between Classes II and III (p = 0.05) and it was confirmed by the Pearson's correlation coefficient (r = - 0.107/p = 0.029). No statistically significant differences were observed between the maxillary sinus volume according to gender (p = 0.06), side (p = 0.37), posterior tooth absence (p = 0.92), sinus membrane thickening (p = 0.47), bony septa (0.89) and vertical skeletal pattern (p = 0.67). No significant differences were observed with age (r = - 0.076/p = 0.109) and the vertical skeletal pattern (r = - 0.078/p = 0.108). CONCLUSION: Maxillary sinus volume was influenced by the sagittal skeletal pattern and was higher in Class III individuals.

Influence of the palatal plane cant and skeletal patterns in the hard palate thickness?

INTRODUCTION: The aim of the present study was to evaluate the thickness of the hard palate at the different angles formed by the palatal plane and the Frankfort horizontal line using computed tomography in patients with different facial patterns for planning the installation of MARPE. MATERIALS AND METHODS: The measurements were analysed in the hard palate of 106 patients. Four regions were selected passing through the mesial face, tangent at the level of the cemento-enamel junction of the premolars and molars. The bone thickness was measured from the floor of the nasal cavity to the cortical bone of the hard palate, 02 measurements with a distance of 05 mm between them (2.5 mm on each side starting from the midsagittal line) and 2 more with a distance of 7 mm between measurements (3.5 mm on each side starting from the midsagittal line). The palatal plane cant was determined based on the palatal plane and the Frankfort horizontal plane. The sagittal skeletal pattern was determined based on the ANB angle and the vertical skeletal pattern based on the SN.Go.Gn angle. RESULTS: Palatal bone thickness was greater in males than in females. Regarding the sagittal skeletal pattern, patients with Class II were found to have a thinner hard palate than Class I and Class III patients. No difference in the vertical skeletal pattern was observed between groups. Regarding the palatal plane cant, bone thickness was greater in patients with clockwise rotation. CONCLUSIONS: Careful planning should be considered in the case of female patients; patients with greater angles of the palatal plane cant and Class II patients have a smaller bone thickness.

Facial pain due to contact between dental implant with the Canalis Sinuosus / Dor facial devido ao contato entre o implante dentário com o Canalis Sinuosus

The Canalis Sinuosus is a structure of the maxilla that allows the passage of the anterosuperior alveolar nerve and has a neurovascular activity. To visualize this structure, Conical Beam Computed Tomography (CBCT) is best recommended. This article aimed to report a case of facial pain after the insertion of a dental implant due to compression of the Canalis Sinuosus. Thus, the implant was removed, followed by the insertion of a bone graft. After that, the facial pain stopped. In conclusion, the identification of anatomical structures in preoperative examinations is essential in surgical dental procedures.

O Canalis Sinuosus é uma estrutura da maxila, que permite a passagem do nervo alveolar anterosuperior e tem uma atividade neurovascular. Para visualizar essa estrutura, a Tomografia Computadorizada de Feixe Cônico (TCFC) é melhor recomendada. Este artigo teve como objetivo relatar um caso de dor facial após a inserção de um implante dentário, devido à compressão do Canalis Sinuosus. Assim, o implante foi removido, seguido pela inserção de um enxerto ósseo. Depois disso, a dor facial foi interrompida. Em conclusão, a identificação de estruturas anatômicas em exames pré-operatórios é essencial em procedimentos odontológicos cirúrgicos.

Assessment of the relationship between tooth inclination and gingival and alveolar bone dimensions using computed tomography of the maxillary anterior teeth: a cross-sectional study.

OBJECTIVE: The present study aimed to investigate the relationship between tooth inclination and gingival and bone dimensions in maxillary anterior teeth. METHODS: This cross-sectional study included cone-beam computed tomography (CBCT) images of 160 maxillary anterior teeth (30 individuals). Tooth inclination, gingival and bone thickness, and distances from cementoenamel junction to alveolar bone crest and gingival margin were measured in the labial surface. The correlations were analyzed using Pearson and partial correlation tests (p≤0.05). RESULTS: In the central incisors, tooth inclination was positively and significantly related to apical bone thickness (R = 0.34, p= 0.001). In the canines, tooth inclination was negatively and significantly related to cervical bone thickness (R = - 0.34, p= 0.01) and positively associated to apical bone thickness (R = 0.36, p= 0.01) and to gingival margin-cementoenamel junction distance (R = 0.31, p= 0.03). In the lateral incisors, tooth inclination was not associated with gingival or bone dimensions. CONCLUSIONS: In the central incisors, the greater the labial tooth inclination, the greater is the apical bone thickness. In the canines, the greater the labial tooth inclination, the smallest is the cervical bone thickness, the greater is the apical bone thickness, and the greater is the gingival margin. Gingival and bone dimensions should be assessed when planning orthodontic treatment involving buccal movement of central incisors and canines.

Discopexia e fisioterapia no tratamento do deslocamento de disco articular sem redução / Discopexy and physiotherapy in the treatment of articular disc displacement withou reduction

A articulação temporomandibular está vunerável a várias condições de anormalidades já bastante conhecidas, dentre elas, o deslocamento do disco articular sem redução, considerado pela literatura o mais comum das patologias desta região. A deterioração do quadro pode ser um indicativo da necessidade cirúrgica. Em específico, no deslocamento de disco sem redução, o reposicionamento definitivo pode ser adquirido através de discopexia e artrocentese. O presente trabalho tem como objetivo relatar um caso clínico de deslocamento de disco articular bilateral sem redução, apresentando a importância da fisioterapia associada à abordagem cirúrgia na recuperação da função mandibular, bem como, reforçar a importância de uma abordagem conjunta entre análise clínica e imaginológica para resolução de casos. Paciente feminino cursando com diversos sintomas em face e pescoço de forma progressiva ao longo de dois anos foi submetida a cirurgia na articulação temporo-mandibular, onde foi feita a discopexia através de ancoragem dos discos articulares com parafusos. A avaliação física, assim como, a imaginológica, ajudaram na confirmação do diagnóstico. A abordagem cirurgica adotada no tratamento deste caso foi descrita na literatura desde o final do século XIX. Conclui-se que, o método utilizado no tratamento do deslocamento de disco sem redução deve ser baseado nos sinais e sintomas do paciente, cuja abordagem deve ser readequada de acordo com as mudanças do quadro apresentado. Nesta análise, a abordagem cirúrgica associada à fisioterapia específica para as estruturas musculoesquelética da face trouxeram resultados positivos(AU)

The temporomandibular joint is responsible for several well-known conditions of abnormalities, among them, the joint disc displacement without reduction, considered by the literature the most common pathology of this region. Deterioration of the condition may be indicative of surgical need. Specifically, in displacement disc without reduction, definitive repositioning can be achieved through discopexy and arthrocentesis. The aim of the present study is to report a case of unilateral articular disc displacement without reduction, as well the importance of physiotherapy associated with the surgical approach in the recovery of mandibular function, as well as reinforcing the importance of a joint approach between clinical and imaging analysis for case resolution. Female patient with several symptoms in the face and neck progressively over two years, underwent surgery in the temporomandibular joint, where discopexy was performed by anchoring the articular discs with screws. The physical assessment, as well as the imaging, helped to confirm the diagnosis. The surgical approach adopted in the treatment of this case has been described in the literature since the end of the 19th century. In conclusion, the method used to treat articular disc displacement without reduction should be based on the patient's signs and symptoms, whose approach should be readjusted according to the changes in the presented picture. In this analysis, the surgical approach associated with specific physiotherapy for the musculoskeletal structures of the face brought positive results(AU)

Diagnostic accuracy of paranasal sinus measurements on multislice computed tomography for sex estimation: A systematic review, meta-analysis, and meta-regression.

This systematic review aimed to answer the question, "Are paranasal measurements obtained with multislice computed tomography able to accurately estimate sex?" This PROSPERO-registered systematic review included six databases and gray literature. Meta-analysis of linear and volumetric data was performed using a random-effects model, mean differences (MDs), and inverse variance. The QUADAS-2 tool-related risk of bias (RoB) and certainty evidence (GRADE approach) were assessed. A total of 1651 articles were initially selected from the main electronic databases for title and abstract screening. After removing duplicates and studies that did not meet the inclusion criteria, 18 studies were eligible for the meta-analysis. The screened studies included 2507 computed tomography of non-pathologic paranasal sinuses of adults aged between 18 and 40 years. Frontal sinus (FS) width (-4.89 mm; p < 0.00001) and maxillary sinus (MS) height (-3.73 mm; p < 0.00001) showed the greatest MD between females and males. Regarding volume, the MD was significant (p < 0.00001) in both paranasal sinuses (-3.01 and -1.04 cm3 , respectively). The best sensitivity (ability to identify males) and specificity (ability to identify females) were found for the anteroposterior (72.3%) and intermaxillary (69%) MS distances, respectively. In general, all studies exhibited low RoB and applicability concerns. The certainty of the evidence was categorized as very low to moderate. Both paranasal sinuses were shown to be dimorphic structures, which could be valuable tools for forensic identification using the FS width and MS anteroposterior distance measurements. However, heterogeneity among studies must be considered.

A neotropical mistletoe influences herbivory of its host plant by driving changes in the associated insect community.

Parasitic plants are important sources of stress and can strongly impact their host plants through direct and indirect associations with other herbivores and their associated organisms. In the tropics, mistletoes are frequent parasitic plants, influencing different trophic levels involved with the host plant. Here, we investigated the direct and indirect influences of multiple partners involved in interactions between the mistletoe Psittachantus robustus and its host tree, Vochysia thyrsoidea. More specifically, we assessed if the presence of the mistletoe modified herbivory levels of its host by altering the diversity of associated insects. We found that insect feeding guild modulated mistletoe influence on insect community, and there were fewer species and individuals of leaf-chewing insects in parasitized than non-parasitized trees. Despite this decrease in leaf-chewing insects, there were increased levels of herbivory in parasitized plants. Mistletoes' presence did not influence the hemipteran sap-sucking insects, but this herbivore guild directly responded to the abundance of their associated ants. Overall, our study found empirical support for the crucial role of mistletoes on their host-associated organisms, ultimately shaping the herbivory levels of their tree hosts. By exposing the distinct effects of the different partners involved, our results shed light on the intricated interactions mediated by parasitic plants, opening the path for new investigations.

The metal post material influences the performance of artefact reduction algorithms in CBCT images.

This study aimed to assess the effect of the MAR tool on the expression of artefacts in different regions of a tooth restored with different types of metal posts. Alveolar sockets (anterior, and posterior region) of a mandible and an unirradicular tooth were used. Cone beam computed tomography scans of the tooth without a metal post, and with cobalt-chromium (Co-Cr), nickel-chromium (Ni-Cr), or silver-palladium (Ag-Pd) were individually obtained, with 2 MAR conditions: disabled, and enabled. In an axial reconstruction, lines of interest (LOIs) were set around the canal: 4 in oblique (mesiobuccal, distobuccal, mesiolingual, distolingual) directions, and 4 in orthogonal (mesial, distal, buccal, lingual) directions. Beam-hardening artefacts expression was determined by calculating the difference in the mean of gray values (DMGV) between the experimental and control groups for each LOI. There was no significant difference in the DMGV values between "without MAR" and "with MAR" for any LOI, in neither anterior nor posterior mandible (p>0.05), for the Ni-Cr and Co-Cr groups. For the Ag-Pd, significant differences in the DMGV values were observed between "without MAR" and "with MAR" for most LOIs (p<0.05), mainly in oblique directions in the anterior region, and mesio-distal direction in the posterior region. MAR acted mostly in hypodense artefacts (negative DMGV). The effectiveness of the MAR tool of the OP300 CBCT unit varied according to the post material tested. It was effective in reducing the expression of artefacts raised by the Ag-Pd post, mainly in the tooth regions affected by hypodense artefacts, regardless of the mandibular region.

Morphological characteristics of the mesiobuccal root in the presence of a second mesiobuccal canal: a micro-CT study.

Objectives: This study investigated the internal morphology of mesiobuccal (MB) roots of maxillary molars with a second mesiobuccal (MB2) canal. Materials and Methods: Forty-seven maxillary first or second molars from Brazilians were scanned using micro-computed tomography. The following measurements were obtained from the MB roots: root thickness, root width, and dentin thickness of the buccal aspect of the first mesiobuccal (MB1) canal, between the MB1 and MB2 canals, and the palatal aspect of the MB2 and MB1 canals at 3 mm from the root apex and in the furcation region. For statistical analysis, the Student's t-test and analysis of variance with the post-hoc Tukey test were used (α = 0.05). Results: In maxillary molars with an MB2 canal, MB roots were significantly thicker (p = 0.0014) and narrower (p = 0.0016) than in maxillary molars without an MB2 canal. The dentin thickness of the palatal aspect of the MB1 canal was also significantly greater than that of MB roots without an MB2 canal at 3 mm from the root apex (p = 0.0007) and in the furcation region (p < 0.0001). In the furcation region of maxillary molars with an MB2 canal, the dentin thickness between the MB1 and MB2 canals was significantly smaller than that in the buccal and palatal aspects (p < 0.0001). Conclusions: The internal morphology of MB roots of maxillary molars with an MB2 canal revealed differences in dentin thickness, root diameter, and distance between the canals when compared with maxillary molars without an MB2 canal.

The metal post material influences the performance of artefact reduction algorithms in CBCT images

Abstract This study aimed to assess the effect of the MAR tool on the expression of artefacts in different regions of a tooth restored with different types of metal posts. Alveolar sockets (anterior, and posterior region) of a mandible and an unirradicular tooth were used. Cone beam computed tomography scans of the tooth without a metal post, and with cobalt-chromium (Co-Cr), nickel-chromium (Ni-Cr), or silver-palladium (Ag-Pd) were individually obtained, with 2 MAR conditions: disabled, and enabled. In an axial reconstruction, lines of interest (LOIs) were set around the canal: 4 in oblique (mesiobuccal, distobuccal, mesiolingual, distolingual) directions, and 4 in orthogonal (mesial, distal, buccal, lingual) directions. Beam-hardening artefacts expression was determined by calculating the difference in the mean of gray values (DMGV) between the experimental and control groups for each LOI. There was no significant difference in the DMGV values between "without MAR" and "with MAR" for any LOI, in neither anterior nor posterior mandible (p>0.05), for the Ni-Cr and Co-Cr groups. For the Ag-Pd, significant differences in the DMGV values were observed between "without MAR" and "with MAR" for most LOIs (p<0.05), mainly in oblique directions in the anterior region, and mesio-distal direction in the posterior region. MAR acted mostly in hypodense artefacts (negative DMGV). The effectiveness of the MAR tool of the OP300 CBCT unit varied according to the post material tested. It was effective in reducing the expression of artefacts raised by the Ag-Pd post, mainly in the tooth regions affected by hypodense artefacts, regardless of the mandibular region.

Resumo O objetivo nesse estudo foi avaliar o efeito da ferramenta de redução de artefato (FRA) na expressão de artefatos em diferentes regiões de um dente restaurado com diferentes tipos de pinos metálicos. Foram usados ​​alvéolos (regiões anterior e posterior) de uma mandíbula e um dente unirradicular. Imagens de tomografia computadorizada de feixe cônico do dente sem pino metálico intracanal e com pinos de cobalto-cromo (Co-Cr), níquel-cromo (Ni-Cr) ou prata-paládio (Ag-Pd) foram individualmente obtidas, com 2 condições de FRA: desativada e ativada. Em uma reconstrução axial, linhas de interesse (LOIs) foram definidas ao redor do canal: 4 em direções oblíquas (mésio-vestibular, disto-vestibular, mésio-lingual e disto-lingual) e 4 em direções ortogonais (mesial, distal, vestibular e lingual). A expressão dos artefatos de endurecimento do feixe foi determinada pelo cálculo da diferença na média dos valores de cinza (DMVC) entre os grupos experimental e controle para cada LOI. Não houve diferença significativa nos valores de DMVC entre as condições "sem FRA" e "com FRA" para nenhuma das LOIs, nem na região anterior nem na região posterior da mandíbula (p>0,05), para os grupos Ni-Cr e Co-Cr. Para o Ag-Pd, diferenças significativas nos valores de DMVC foram observadas entre "sem FRA" e "com FRA" para a maioria das LOIs (p<0,05), principalmente nas direções oblíquas na região anterior, e na direção mesio-distal na região posterior. A FRA atuou principalmente em artefatos hipodensos (DMVC negativos). A eficácia da FRA disponível no aparelho de TCFC OP300 variou de acordo com o material do pino testado. Ela foi efetiva na redução da expressão de artefatos originados por pinos de Ag-Pd, principalmente nas regiões do dente afetadas por artefatos hipodensos, independentemente da região mandibular.

Systematic review and meta-analysis of lingual foramina anatomy and surgical-related aspects on cone-beam computed tomography: a PROSPERO-registered study.

PURPOSE: This study aimed to summarize the evidence regarding lingual foramen (LF) characteristics using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: A registered systematic review (#42,019,145,962) was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statements. An electronic search without date or language restrictions was performed in five databases, including grey literature (Google Scholar and ProQuest). The Meta-Analysis of Statistics Assessment and Review Instrument was used to evaluate the selected studies. RESULTS: A total of 6641 articles were identified, and 26 studies (8255 CBCT scans) were selected after a three-step selection process. There was a female predominance, and age ranged between 10 and 93 years. A total of 4336 LFs were observed among men (n = 2042) and women (n = 2294). Of this LF-related sample, 43.5% of the studies were from Asia, followed by Europe (33.5%), North America (14%), and South America (9%). Different distances from the LF to the alveolar crest (11.04-20.4 mm), buccal (4.73-4.91 mm), and lingual (8.75 mm) cortices and the inferior border of the mandible (8.48-26.59 mm) were evaluated. CONCLUSION: In summary, this systematic review found that LF is an anatomical structure with a high prevalence among the included studies (greater than 90%), regardless of the population evaluated. The occurrence of at least one LF was the most common pattern.

Tomographic assessment of infrazygomatic crest bone depth for extra-alveolar miniscrew insertion in subjects with different vertical and sagittal skeletal patterns.

OBJECTIVE: To evaluate bone availability at the infrazygomatic crest for extra-alveolar bone miniscrew insertion in subjects with different vertical and sagittal skeletal patterns. SETTING AND SAMPLE POPULATION: Measurements of the infrazygomatic crest were performed on multislice computed tomography scans from 58 adults with different skeletal patterns. MATERIALS AND METHODS: Infrazygomatic crest bone depth was measured at 4, 5 and 6 mm from the cementoenamel junction (CEJ) of the maxillary first molar at three different angles (60°, 70° and 80°) in the first molar occlusal plane. The sagittal and vertical skeletal patterns were determined. Analysis of variance followed by Tukey's post hoc test was used (P ≤ .05). RESULTS: Bone depth was greater near the CEJ (8.7 ± 3.1 mm) and lower in the apical area (5.8 ± 2.7 mm). In Class II subjects, considering 6 mm from the CEJ, there was a significantly lower depth at the 80° angle (5.4 ± 2.5 mm) than at 60° (8.6 ± 3.5 mm; P = .007). In mesofacial subjects, considering 5 and 6 mm from the CEJ, bone depth was lower at 80° (5.7 ± 3.2 mm and 5.3 ± 2.5 mm) than at 60° considering 4 mm from the CEJ (P ≤ .019). CONCLUSION: Bone availability was lower at the apical level, especially in Class II and mesofacial subjects. Therefore, when the planned insertion site is located in the apical direction, it is recommended to choose shorter miniscrews (2.0 x 12mm) and a smaller insertion angle (60°) and/or to plan a miniscrew bone insertion deep enough to allow bicortical fixation.

Global trends in the trophic specialisation of flower-visitor networks are explained by current and historical climate.

Trophic specialisation is known to vary across space, but the environmental factors explaining such variation remain elusive. Here we used a global dataset of flower-visitor networks to evaluate how trophic specialisation varies between latitudinal zones (tropical and temperate) and across elevation gradients, while considering the environmental variation inherent in these spatial gradients. Specifically, we assessed the role of current (i.e., net primary productivity, temperature, and precipitation) and historical (i.e., temperature and precipitation stability) environmental factors in structuring the trophic specialisation of floral visitors. Spatial variations in trophic specialisation were not explained by latitudinal zones or elevation. Moreover, regardless of network location on the spatial gradient, there was a tendency for higher trophic specialisation in sites with high productivity and precipitation, whereas historical temperature stability was related to lower trophic specialisation. We highlight that both energetic constraints in animal foraging imposed by climate and resource availability may drive the global variation in trophic specialisation.