Marginal bone loss in the second molar related to impacted mandibular third molars : comparison between panoramic images and cone beam computed tomography

Deciding whether or not to extract third molars remains a controversial situation in dental practice. Image exams support this decision by enabling a close view of the third molar, its adjacent bone and its relationship with the second molar. This study aimed to assess and compare second molar bone loss adjacent to impacted mandibular third molar in panoramic radiographs (PAN) and cone beam computed tomography (CBCT) scans. A sample of 70 patients was selected (n=124 teeth). Each patient had a set of a panoramic radiograph and CBCT scans consecutively taken for dental treatment purposes. In PAN and CBCT, mandibular third molars were classified based on their position and bone loss of the adjacent second molar. Agreement between PAN and CBCT scans was assessed and quantified. Outcomes of bone loss assessment were different between PAN and CBCT scans (p<0.05). Bone loss was found in 62.9% of the PAN, while in CBCT scans it was found in 80%. In particular, nearly 29% (n=27) of the teeth that were classified without bone loss in PAN were classified with bone loss in CBCT scans. Mesioangular and horizontal third molars had a statistically significant association with bone loss of the adjacent second molars (p<0.05). In general, PAN underestimated the severity of bone loss compared to CBCT scans (p<0.05). Diagnosing second molar bone loss due to impaction of adjacent third molar in PAN may be challenging because of false negatives. Impacted third molars justify preoperative CBCT scans if second molar bone loss needs to be precisely assessed for a more detailed and reliable treatment plan

Prevalence of Oral Lesions in Hospitalized Patients with Infectious Diseases in Northern Brazil

The aim of this study was to assess the prevalence of oral lesions in infectious-contagious diseases patients being treated in the University Hospital of the Federal University of Pará, northern Brazil. One hundred seven patients with infectious diseases were clinically investigated for oral lesions at the University Hospital of Pará, northern Brazil. From total sample, most patients were men (65.7%) with a mean age of 45.4 years. About prevalence of systemic diseases, tuberculosis was the most frequent illness, followed by AIDS, hepatitis types B and C, leishmaniasis, and meningitis. Analyzing oral manifestations, periodontal diseases and candidiasis were the most prevalent diseases in both genders, followed by recurrent aphthous ulcers, saburral tongue, simplex herpes, and squamous cell carcinoma. Of all 107 patients, only 10 males and 6 females did not present any oral manifestation. There was no statistical difference between genders with any systemic condition (P>0.05). The great prevalence of oral manifestations in hospitalized patients with systemic disorder emphasizes the need of integral dental care in this context, aiming at a multidisciplinary approach of patients. Therefore, presence of some oral conditions, such as candidiasis, should be an alert to different systemic conditions, once in assistance with physicians; dentists can influence the early diagnosis and treatment

Prevalence of Oral Lesions in Hospitalized Patients with Infectious Diseases in Northern Brazil

Brazil. One hundred seven patients with infectious diseases were clinically investigated for oral lesions at the University Hospital of Pará, northern Brazil. From total sample, most patients were men (65.7%) with a mean age of 45.4 years. About prevalence of systemic diseases, tuberculosis was the most frequent illness, followed by AIDS, hepatitis types B and C, leishmaniasis, and meningitis. Analyzing oral manifestations, periodontal diseases and candidiasis were the most prevalent diseases in both genders, followed by recurrent aphthous ulcers, saburral tongue, simplex herpes, and squamous cell carcinoma. Of all 107 patients, only 10 males and 6 females did not present any oral manifestation. There was no statistical difference between genders with any systemic condition ( &gt; 0.05). The great prevalence of oral manifestations in hospitalized patients with systemic disorder emphasizes the need of integral dental care in this context, aiming at a multidisciplinary approach of patients. Therefore, presence of some oral conditions, such as candidiasis, should be an alert to different systemic conditions, once in assistance with physicians; dentists can influence the early diagnosis and treatment

Two-dimensional radiographs versus cone-beam computed tomography in planning mini-implant placement : a systematic review

This study aimed to compare two-dimensional radiographs and cone beam computed tomography (CBCT) images for mini-implant planning. A search was performed in PubMed, Embase, Web of Science, Cochrane Library and Google Scholar electronic databases accord

Analysis of predictors of root resorption in the orthodontic treatment (Part II)

This study aims to analyze the predictors of root resorption in orthodontic treatment. From 407 records, 377 pretreatment and posttreatment periapical radiographs of permanent maxillary central incisors of 199 patients treated with fixed appliances were divided according to the apical morphologies: pipetteshaped, dilacerated, pointed, rounded and rectangular; crown/root ratio; and presence or absence of partial hypodontia. Changes in root length between the onset and completion of orthodontic treatment were measured in digitized images and statistically compared using T student, one-way ANOVA and Tukey tests. The apical morphology influenced the occurrence of root resorption; teeth with rounded and rectangular apical morphologies were more resistant to root resorption (.001 and .0007, respectively). Short teeth and the presence of partial hypodontia or multiple partial hypodontia did not present greater tendency to root resorption (.1008 and .1544, respectively). The results indicated that abnormal apical morphology is a predictor of external apical root resorption after corrective orthodontic therapy. However, short teeth and partial hypodontia did not increase the prevalence of apical resorption. The susceptibility or individual predisposition to tooth resorptions during orthodontic treatment may be related to the apical morphology

Cone-beam computed tomography in Endodontics:an exploratory research of the main clinical applications

This study revisited three oral radiology centers (ORC) and screened the main clinical indications that justified the request for cone-beam computed tomography (CBCT) examination in Endodontics. The databases of three ORCs were searched for requests of CBCT exams taken for Endodontic purposes over the last two years. The extracted data consisted of the total number of CBCT exams, the clinical indication in the endodontic field that justified the CBCT exam, the outcome of each exam (from the report of Oral Radiologists), and demographic data of the patients. From the total CBCT exams (n = 4,583), nearly 13% (n = 611) were taken for Endodontic purposes. Most of the clinical indications were related to root fractures (65%) and periapical lesions/disease (24.1%). Radiologists’ reports hypothesized more often toward periapical lesion/disease (70.5%), root fracture (51.4%) and accidents/complications (25.2%). Some clinical indications significantly varied based on age. In particular, post-traumatic imaging and the investigation of root resorption were more common in young patients, while the prevalence of exams for the investigation of pulpal calcifications and root fractures increased with age. More interestingly, there was a significant disagreement between the clinical indication that justified the CBCT examinations and the outcomes retrieved from radiologists’ reports (p &lt; 0.005). This study illustrates the broad spectrum of CBCT applications for the diagnosis, treatment planning and follow-up in Endodontics. Attention is necessary to the disagreements between clinical indications and imaging outcomes, especially because certain conditions in the routine Endodontics are only visible with the aid of advanced tools.Este estudio revisitó tres centros de radiología oral (CRO) y cribo las principales indicaciones clínicas que justificaron la solicitud de examen por tomografía computarizada de haz cónico (CBCT) en endodoncia. Se realizaron búsquedas en las bases de datos de tres CRO en busca de solicitudes de exámenes CBCT realizados con fines endodónticos durante los últimos dos años. Los datos extraídos consistieron en el número total de exámenes CBCT, la indicación clínica en el campo endodóntico que justificó el examen CBCT, el resultado de cada examen (del informe de los radiólogos orales) y los datos demográficos de los pacientes. Del total de exámenes CBCT (n = 4583), casi el 13% (n = 611) se tomaron con fines de endodoncia. La mayoría de las indicaciones clínicas se relacionaron con fracturas radiculares (65%) y lesiones / enfermedades periapicales (24,1%). Los informes de los radiólogos plantearon con mayor frecuencia la hipótesis de lesión / enfermedad periapical (70,5%), fractura de raíz (51,4%) y accidentes / complicaciones (25,2%). Algunas indicaciones clínicas variaron significativamente según la edad. En particular, las imágenes postraumáticas y la investigación de la reabsorción radicular fueron más comunes en pacientes jóvenes, mientras que la prevalencia de exámenes para la investigación de calcificaciones pulpares y fracturas radiculares aumentó con la edad. Más interesante aún, hubo un desacuerdo significativo entre la indicación clínica que justificaba los exámenes CBCT y los resultados obtenidos de los informes de los radiólogos (p &lt;0,005). Este estudio ilustra el amplio espectro de CBCT para el diagnóstico, la planificación del tratamiento y el seguimiento en endodoncia. Es necesario prestar atención a los desacuerdos entre las indicaciones clínicas y los resultados de las imágenes, especialmente porque ciertas condiciones en la endodoncia de rutina solo son visibles con la ayuda de herramientas avanzadas.O presente estudo revisitou três centros de radiologia odontológica (ORC) e rastreou as principais indicações clínicas que justificaram a solicitação do exame de tomografia computadorizada de feixe cônico (TCFC) em Endodontia. Os bancos de dados de três ORCs foram pesquisados em busca de solicitações de exames CBCT realizados para fins endodônticos nos últimos dois anos. Os dados extraídos consistiram no número total de exames de TCFC, a indicação clínica na área endodôntica que justificou o exame de TCFC, o resultado de cada exame (a partir do laudo do Radiologista Oral) e os dados demográficos dos pacientes. Do total de exames de TCFC (n = 4.583), quase 13% (n = 611) foram feitos para fins endodônticos. A maioria das indicações clínicas foi relacionada a fraturas radiculares (65%) e lesões / doenças periapicais (24,1%). Os laudos dos radiologistas levantaram a hipótese mais frequentemente de lesão / doença periapical (70,5%), fratura radicular (51,4%) e acidentes / complicações (25,2%). Algumas indicações clínicas variaram significativamente com base na idade. Em particular, a imagem pós-traumática e a investigação de reabsorção radicular foram mais comuns em pacientes jovens, enquanto a prevalência de exames para investigação de calcificações pulpares e fraturas radiculares aumentou com a idade. Mais curiosamente, houve uma discordância significativa entre a indicação clínica que justificou os exames de TCFC e os resultados obtidos dos relatórios dos radiologistas (p &lt;0,005). Este estudo ilustra o amplo espectro de aplicações da TCFC para o diagnóstico, planejamento de tratamento e acompanhamento em Endodontia. É preciso atentar para as divergências entre as indicações clínicas e os desfechos de imagem, principalmente porque certas condições da rotina da Endodontia só são visíveis com o auxílio de ferramentas avançadas

Geography and ecology shape the phylogenetic composition of Amazonian tree communities

Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran\u27s eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R$^{2}$ = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R$^{2}$ = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types