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1.
J Clin Pediatr Dent ; 48(3): 139-145, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38755992

RESUMO

The endodontic treatment of immature permanent teeth with necrotic pulp is a significant clinical challenge. The success of regenerative endodontic procedure is highly dependent on disinfection of the root canal and an accurate anatomical knowledge of the root canal. The aim of this study was to use micro-computed tomography (micro-CT) analysis to investigate the configuration of root canals in the upper permanent third maxillary molars with incomplete root development in their coronal, apical and middle third portions. Thirty immature third permanent maxillary molars were scanned using a micro-CT system. Then, we measured the diameters and areas of the root canal in the coronal, middle and apical third of the roots. The ratio between the long and short diameter of each root canal was then calculated and the canals were divided into several groups: round, oval, long oval, flat and irregular. The round configuration was not observed in the distobuccal and mesiobuccal roots in any of their anatomical regions. Oval and long oval canals predominated in the distobuccal root. The greatest variations were observed in the mesiobuccal root, with the ribbon-shaped canal predominating in the middle region and an irregular shape in the apical region. In the coronal region of the palatal canal, the round configuration predominated; in the middle third, we observed an almost equivalent distribution between round and oval configurations; apically, the oval shape predominated. In conclusion, we observed significant complexity and variation in the morphology and configuration of root canals in immature permanent molars, thus generating additional obstacles for the success of regenerative endodontics.


Assuntos
Cavidade Pulpar , Maxila , Dente Serotino , Microtomografia por Raio-X , Humanos , Microtomografia por Raio-X/métodos , Cavidade Pulpar/diagnóstico por imagem , Cavidade Pulpar/anatomia & histologia , Maxila/diagnóstico por imagem , Maxila/anatomia & histologia , Dente Serotino/diagnóstico por imagem , Dente Serotino/anatomia & histologia , Criança , Raiz Dentária/diagnóstico por imagem , Raiz Dentária/anatomia & histologia
2.
J Forensic Odontostomatol ; 42(1): 12-21, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38742568

RESUMO

The primary step in forensic odontological analysis is sex determination. The present study is one of the few studies that evaluated the accuracy of the combination of canine tooth root length and crown measurements for sex determination. The study sample comprised 196 cone-be am computed tomographic scans of individuals aged 20-80 years distributed in five age categories: 20-29, 30-39, 40-49, 50-59, and 60+ years old. Different parameters, such as width, length, and ratio measurements for the crown and root of each maxillary and mandibular canine tooth, were examined and recorded. The findings indicated that maxillary canines had greater sex dimorphism ability (87.3%) than mandibular canines (80.6%). Total tooth length and root length of maxillary canine were the most pronounced variables in the differentiation of sex groups. When the combination of the mandibular and maxillary measurements was considered, the accuracy for sex dimorphism was 85.7%. By using ratio variables, the accuracy was reduced to 68.9%. According to the findings of this study, total tooth length and root length are the most discriminant variables of canine teeth. These variables are more reliable sex indicators than crown measurements.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Dente Canino , Odontologia Legal , Caracteres Sexuais , Coroa do Dente , Raiz Dentária , Humanos , Dente Canino/diagnóstico por imagem , Dente Canino/anatomia & histologia , Feminino , Masculino , Pessoa de Meia-Idade , Coroa do Dente/diagnóstico por imagem , Coroa do Dente/anatomia & histologia , Idoso , Raiz Dentária/diagnóstico por imagem , Raiz Dentária/anatomia & histologia , Adulto , Odontologia Legal/métodos , Idoso de 80 Anos ou mais , Adulto Jovem , Odontometria/métodos , Maxila/diagnóstico por imagem , Maxila/anatomia & histologia
3.
BMC Oral Health ; 24(1): 543, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38724952

RESUMO

BACKGROUND: In complex teeth like maxillary premolars, endodontic treatment success depends on a complete comprehension of root canal anatomy. The research on mandibular premolars' root canal anatomy has been extensive and well-documented in existing literature. However, there appears to be a notable gap in available data concerning the root canal anatomy of maxillary premolars. This study aimed to explore the root canal morphology of maxillary premolars using cone-beam computed tomography (CBCT) imaging, considering age and gender variations. METHODS: From 500 patient CBCT scans, 787 maxillary premolar teeth were evaluated. The sample was divided by gender and age (10-20, 21-30, 31-40, 41-50, 51-60, and 61 years and older). Ahmed et al. classification system was used to record root canal morphology. RESULTS: The most frequent classifications for right maxillary 1st premolars were 2MPM1 B1 L1 (39.03%) and 1MPM1 (2.81%), while the most frequent classifications for right maxillary 2nd premolars were 2MPM1 B1 L1 (39.08%) and 1MPM1 (17.85%). Most of the premolars typically had two roots (left maxillary first premolars: 81.5%, left maxillary second premolars: 82.7%, right maxillary first premolars: 74.4%, right maxillary second premolars: 75.7%). Left and right maxillary 1st premolars for classes 1MPM1 and 1MPM1-2-1 showed significant gender differences. For classifications 1MPM1 and 1MPM1-2-1, age-related changes were seen in the left and right maxillary first premolars. CONCLUSION: This study provides novel insights into the root canal anatomy of maxillary premolars within the Saudi population, addressing a notable gap in the literature specific to this demographic. Through CBCT imaging and analysis of large sample sizes, the complex and diverse nature of root canal morphology in these teeth among Saudi individuals is elucidated. The findings underscore the importance of CBCT imaging in precise treatment planning and decision-making tailored to the Saudi population. Consideration of age and gender-related variations further enhances understanding and aids in personalized endodontic interventions within this demographic.


Assuntos
Dente Pré-Molar , Tomografia Computadorizada de Feixe Cônico , Cavidade Pulpar , Maxila , Humanos , Dente Pré-Molar/diagnóstico por imagem , Dente Pré-Molar/anatomia & histologia , Masculino , Feminino , Adolescente , Maxila/diagnóstico por imagem , Maxila/anatomia & histologia , Cavidade Pulpar/diagnóstico por imagem , Cavidade Pulpar/anatomia & histologia , Adulto , Arábia Saudita , Pessoa de Meia-Idade , Criança , Estudos Transversais , Adulto Jovem , Fatores Sexuais , Fatores Etários
4.
Dental Press J Orthod ; 29(2): e24spe2, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38775602

RESUMO

INTRODUCTION: The superimposition of 3 dimensions (3D) digital models has been increasingly used for evaluating dental changes resulting from orthodontic treatment, and different superimposition techniques have been described. Although the maxilla has areas with greater stability for superimposition, such as the palatal rugae, there is still no reliable method for superimposing models of the lower arch. OBJECTIVE: Therefore, this article aims to describe a technique for superimposing virtual models. METHODS: To evaluate pre- and post-orthodontic treatment changes, the Geomagic Qualify 2013 software (3D Systems®, Rock Hill, South Carolina, USA) was used, with reference points in the maxilla, including the rugae and a reference area in the palate and midpalatal raphe. The lower arch was superimposed using the maximum habitual intercuspation (MHI) model as reference. RESULTS AND CONCLUSION: 3D models superimposition using palatal rugae and MHI occlusion seems to offer satisfactory results in the interpretation of clinical changes at different follow-up moments in terms of development and/or orthodontic treatment.


Assuntos
Imageamento Tridimensional , Modelos Dentários , Software , Humanos , Imageamento Tridimensional/métodos , Maxila/anatomia & histologia , Palato Duro/anatomia & histologia , Palato/anatomia & histologia , Oclusão Dentária , Mandíbula/anatomia & histologia
5.
BMC Oral Health ; 24(1): 568, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38745216

RESUMO

BACKGROUND: Understanding the tooth anatomy is crucial for ensuring effective endodontic treatment. This study investigated the root canal morphology of the second mesiobuccal (MB2) canal in maxillary first molars (MFMs) in a Chinese population using cone-beam computed tomography (CBCT). METHODS: This study evaluated 486 MFMs with MB2 canals from 285 participants undergoing CBCT examination and determined the Vertucci's classification and position of the MB2 canal orifice. The prevalence of the MB2 canal was correlated with the sex, age, and tooth side. The correlations between the prevalence of the MB2 canal and sex and tooth side were assessed using the Fisher's exact test. The chi-square test was used for evaluating the correlation between the prevalence of the MB2 canal and age. RESULTS: The number of type II, III, IV, V, VI, VII, and other root canals in the MFMs was 30.9%, 0.6%, 65.0%, 1.2%, 1.2%, 0.4%, and 0.6%, respectively. Among the 201 cases with bilateral inclusion, 87.6% showed consistent canal configuration. Results of the first clear apparent position (FCAP) of the MB2 canals showed that 434, 44, and 3 teeth had FCAP at the upper, middle, and bottom one-third of the root, respectively. The FCAPs of the MB2 canal in the MFMs with types II, IV, and VI, as well as types III and V canals showed significant differences (p<0.05). The horizontal distance between the MB1 and MB2 canal orifices in the type II canals of MFMs was significantly lesser than those in the type IV canals of MFMs (p < 0.01). The longitudinal distance between the pulp chamber floor plane and MB2 canal orifice significantly correlated with age (p < 0.05). CONCLUSIONS: The morphology of the mesiobuccal root canal in the MFMs is complex. Complete understanding of the anatomical morphology of the root canal combined with the CBCT and dental operating microscope is necessary for the accurate detection of the MB2 canal and consequently improved success rate of root canal treatment. Our study findings can help endodontists improve endodontic treatment outcomes.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Cavidade Pulpar , Maxila , Dente Molar , Humanos , Tomografia Computadorizada de Feixe Cônico/métodos , Dente Molar/anatomia & histologia , Dente Molar/diagnóstico por imagem , Masculino , Feminino , Adulto , Cavidade Pulpar/diagnóstico por imagem , Cavidade Pulpar/anatomia & histologia , Pessoa de Meia-Idade , Maxila/diagnóstico por imagem , Maxila/anatomia & histologia , China , Adolescente , Idoso , Adulto Jovem , População do Leste Asiático
6.
J Dent ; 145: 105014, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38648874

RESUMO

OBJECTIVES: To assess the impact of including the palate and the number of images recorded during intraoral digital scanning procedure on the accuracy of complete arch scans. METHODS: An experienced operator conducted 40 digital scans of a 3D printed maxillary model and divided them into two groups: 20 with inclusion of the palate (PAL) and 20 without (NPAL). Each set of scans was performed using an intraoral scanner (IOS) (Trios 5; 3Shape A/S; Copenhagen, Denmark). The resulting STL files were imported into the Geomagic Control X software (3D Systems, Rock Hill, SC, USA) for accuracy comparison. A reference STL file was created using a 3Shape E3 laboratory scanner (3Shape Scanlt Dental 2.2.1.0; Copenhagen, Denmark). The number of images captured was recorded during the scanning procedure. RESULTS: In the case of the right side no statistically significant difference in trueness was detected (84 µm ± 45.6 for PAL and 80.4 ± 40.4 µm for NPAL). In the case of the left side no significant difference in trueness was observed (215.1 ± 70.2 µm for PAL and 233.9 ± 70.7 µm for NPAL). In the case of the arch distortion a statistically significant difference in trueness was seen between the two types of scans (135.3 ± 71.9 µm for PAL and 380.4 ± 255.1 µm for NPAL). The average number of images was 831.25, and 593.8 for PAL and NPAL, respectively. CONCLUSIONS: Scanning of the palatal area can significantly improve the accuracy of dental scans in cases of complete arches. In terms of the number of images, based on the current results, obvious conclusions could not be drawn, and further investigation is required. CLINICAL SIGNIFICANCE: Scanning the palate may be beneficial for improving the accuracy of intraoral scans in dentate patients. Consequently, this should be linked to an appropriate scanning strategy that predicts palatal scanning.


Assuntos
Arco Dental , Técnica de Moldagem Odontológica , Maxila , Modelos Dentários , Palato , Humanos , Palato/diagnóstico por imagem , Palato/anatomia & histologia , Arco Dental/diagnóstico por imagem , Arco Dental/anatomia & histologia , Maxila/diagnóstico por imagem , Maxila/anatomia & histologia , Processamento de Imagem Assistida por Computador/métodos , Desenho Assistido por Computador , Imageamento Tridimensional/métodos , Software , Impressão Tridimensional , Técnicas In Vitro , Materiais para Moldagem Odontológica
7.
Int J Oral Maxillofac Implants ; 39(2): 243-253, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38657217

RESUMO

PURPOSE: To validate an innovative 3D volumetric method of evaluating tissue changes proposed by Lee et al in 2020 by comparing the results of this method-in which the scanned peri-implant surfaces were transformed, visualized, and analyzed as 3D objects-to the results reported by an existing method based on calculation of the mean distance between measured surfaces. The null hypothesis was that there was no statistically significant difference between the two methods. Additionally, the present study evaluated peri-implant tissue changes 5 years after single implant placement in the esthetic zone. MATERIALS AND METHODS: Both methods were applied to 11 oral implant site casts (6 maxillary central incisor sites, 5 maxillary lateral incisor sites) taken from 11 patients at crown placement and at follow-up examinations 5 years later. The methods are based on digital workflows in which the reference and 5-year casts are scanned and the resulting STL files are superimposed and analyzed for three regions of interest (mesial papilla, central area, and distal papilla). The volumetric changes reported by the Lee et al method and the mean distance method were calculated and compared using the Spearman rank correlation coefficient (P < .01) and the Wilcoxon signed-rank test (P < .05). RESULTS: The correlation between the two sets of measurements was very high (Spearman rank correlation coefficient = 0.885). The new volumetric method indicated a mean volume loss of 2.82 mm3 (SD: 5.06), while the method based on the measurement of mean distance showed a mean volume loss of 2.92 mm3 (SD: 4.43; Wilcoxon signed-rank test result: P = .77). No statistically significant difference was found. The two methods gave equivalent results, and the null hypothesis was accepted. CONCLUSIONS: The new volumetric method was validated and can be considered a trustworthy tool.


Assuntos
Implantes Dentários para Um Único Dente , Imageamento Tridimensional , Humanos , Imageamento Tridimensional/métodos , Maxila/cirurgia , Maxila/anatomia & histologia , Feminino , Implantação Dentária Endóssea/métodos , Modelos Dentários , Coroas , Masculino , Adulto , Incisivo/anatomia & histologia
8.
BMC Oral Health ; 24(1): 495, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38671430

RESUMO

BACKGROUND: Dental casts made utilising digital workflow are becoming more common because to their speed and cost savings. However, studies on their dimensional accuracy over time with diverse designs are missing. OBJECTIVE: The aim of this in vitro study was to assess the dimensional stability of 3D-printed edentulous and fully dentate hollowed maxillary models with 50-micrometer resolution over 1 day, 14 days, and 28 days using surface matching software. METHODS: Scanned edentulous and fully dentate maxillary typodont models were used as references. The models were scanned by a desktop lab scanner of 15-micrometer accuracy (D900, 3Shape). Then, the files were used in designing software (Meshmixer, Autodesk) to create hollowed maxillary casts. Fifteen edentulous and 15 fully dentate (total of 30) models were printed using a DLP lab printer (Cara print 4.0, Kulzer). The 3D-printed models were scanned using the same desktop lab scanner of 15-micrometer accuracy at intervals of baseline days, 1 day, 14 days, and 28 days to assess the effect of aging (n = 120). The dimensional changes were quantified and compared using the root mean square (RMS) method, expressed in micrometres (µm). The study employed repeated measures analysis of variance (ANOVA) to assess and compare the root mean square (RMS) values across the variables. The data was analysed using SPSS (26, Chicago, Illinois, USA). RESULTS: The RMS of the edentulous models rapidly increased from a mean value of 0.257 at the beginning of the study to 0.384 after twenty-eight days. However, the mean RMS values for the dentate models did not change much over the four intervals. It varied only from 0.355 to 0.347. The mean values for edentulous patients increased from 0.014 to 0.029 during the period from baseline to twenty-eight days. However, the mean average values decreased for the dentate models from 0.033 to 0.014 during this period. By utilizing ANOVA, mean RMS values increased insignificantly till one day but significantly to fourteen and twenty-eight days. Dentate model mean values differed insignificantly across four intervals. Repeated measures ANOVA for combined and separated data showed no significant differences across edentulous, dentate, and total models over times. CONCLUSION: The study revealed changes in the dimensions of 3D-printed edentulous models over a span of 3 and 4 weeks. Caution should be applied when using 3D-printed dental master models for constructing definitive prostheses on edentulous models over a period of 3 to 4 weeks.


Assuntos
Maxila , Modelos Dentários , Impressão Tridimensional , Humanos , Maxila/anatomia & histologia , Fatores de Tempo , Software , Desenho Assistido por Computador , Técnicas In Vitro
9.
J Endod ; 50(6): 807-813, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38493831

RESUMO

INTRODUCTION: Information concerning the anatomy of the physiological foramen is still limited. The aim of this study was to investigate the distance between the physiological and anatomic apex, the shape and diameter of the physiological foramen in maxillary (Mx) and mandibular premolars (Mn). METHODS: The anatomy of the apex of 229 maxillary (first: MxP1; second: MxP2) and 221 mandibular premolars (first: MnP1; second: MnP2) from a mixed Swiss-German population was investigated by means of microcomputed tomography and 3-dimensional software imaging. RESULTS: The following results were obtained in the presence of a main physiological foramen. 1. The distance between the physiological and anatomic foramen was 0.29-0.99 mm (MxP1), 0.21-1.03 mm (MxP2), 0.13-0.8 (MnP1), and 0.15-1.41 (MnP2). 2. The mean narrow and wide diameters of the physiological foramen were 0.19-0.33 mm (MxP1), 0.25-0.42 mm (MxP2), 0.28-0.37 (MnP1), and 0.28-0.40 (MnP2). 3. The most common physiological foramen shape was oval (66.7% MxP1, 89.7% MxP2, 91.8% MnP1, 64.4% MnP2). CONCLUSION: Considering the recommended preparation sizes based on a size corresponding to the friction, that is at the narrowest point in the area of the apical constriction (physiological foramen), and within the limitations of this ex vivo microcomputed tomography study, a final preparation size could be chosen when considering the pertaining morphologic considerations; yet, to a minimum ISO 30 size.


Assuntos
Dente Pré-Molar , Mandíbula , Maxila , Microtomografia por Raio-X , Humanos , Dente Pré-Molar/anatomia & histologia , Dente Pré-Molar/diagnóstico por imagem , Maxila/anatomia & histologia , Maxila/diagnóstico por imagem , Mandíbula/anatomia & histologia , Mandíbula/diagnóstico por imagem , Imageamento Tridimensional/métodos , Ápice Dentário/anatomia & histologia , Ápice Dentário/diagnóstico por imagem , Cavidade Pulpar/anatomia & histologia , Cavidade Pulpar/diagnóstico por imagem , Masculino , Feminino , Adulto
10.
J Dent ; 145: 104939, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38521237

RESUMO

OBJECTIVES: To measure the impact of superimposition methods and the designated comparison area on accuracy analyses of dentate models using an ISO-recommended 3-dimensional (3D) metrology-grade inspection software (Geomagic Control X; 3D Systems; Rock Hill, South Carolina; USA). MATERIALS AND METHODS: A dentate maxillary typodont scanned with a desktop scanner (E4; 3 Shape; Copenhagen; Denmark) and an intraoral scanner (Trios 4; 3 Shape; Copenhagen; Denmark) was used as reference. Eight groups were created based on the core features of each superimposition method: landmark-based alignment (G1); partial area-based alignment (G2); entire tooth area-based alignment (G3); double alignment combining landmark-based alignment with entire tooth area-based alignment (G4); double alignment combining partial area-based alignment with entire tooth area-based alignment (G5); initial automated quick pre-alignment (G6); initial automated precise pre-alignment (G7); and entire model area-based alignment (G8). Diverse variations of each alignment and two regions for accuracy analyses (teeth surface or full model surface) were tested, resulting in a total of thirty-two subgroups (n = 18). The alignment accuracy between experimental and reference meshes was quantified using root mean square (RMS) error as trueness and its repeatability as precision. The descriptive statistics, a factorial repeated measures analysis of variance (ANOVA) and a post hoc Tuckey multiple comparison tests were used to analyze the trueness, and precision (α = 0.05). RESULTS: A total of 576 superimpositions were performed. The unique partial area-based superimposition method demonstrated the least precise alignment and was the sole group to exhibit a significant difference (p<.001). Automated initial pre-alignments demonstrated similar accuracy to other superimposition methods (p>.05). Double alignments did not result in accuracy improvement (p>.05). The designated comparison area displayed differences in both trueness (p<.001) and precision (p<.001), leading to an overall discrepancy of 8 ± 4 µm between selecting the teeth surface or full model surface. CONCLUSIONS: The superimposition method choice within the tested software did not impact accuracy analyses, except when the alignment relies on a unique and reduced area, such as the palatal rugae, a single tooth, or three adjacent teeth on one side. CLINICAL SIGNIFICANCE: The superimposition method choice within the tested ISO-recommended 3D inspection software did not impact accuracy analyses.


Assuntos
Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Modelos Dentários , Software , Humanos , Imageamento Tridimensional/métodos , Processamento de Imagem Assistida por Computador/métodos , Pontos de Referência Anatômicos , Reprodutibilidade dos Testes , Maxila/anatomia & histologia , Dente/anatomia & histologia , Dente/diagnóstico por imagem
11.
J Dent ; 144: 104971, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38548165

RESUMO

OBJECTIVES: In prosthodontic procedures, traditional computer-aided design (CAD) is often time-consuming and lacks accuracy in shape restoration. In this study, we combined implicit template and deep learning (DL) to construct a precise neural network for personalized tooth defect restoration. METHODS: Ninety models of right maxillary central incisor (80 for training, 10 for validation) were collected. A DL model named ToothDIT was trained to establish an implicit template and a neural network capable of predicting unique identifications. In the validation stage, teeth in validation set were processed into corner, incisive, and medium defects. The defective teeth were inputted into ToothDIT to predict the unique identification, which actuated the deformation of the implicit template to generate the highly customized template (DIT) for the target tooth. Morphological restorations were executed with templates from template shape library (TSL), average tooth template (ATT), and DIT in Exocad (GmbH, Germany). RMSestimate, width, length, aspect ratio, incisal edge curvature, incisive end retraction, and guiding inclination were introduced to assess the restorative accuracy. Statistical analysis was conducted using two-way ANOVA and paired t-test for overall and detailed differences. RESULTS: DIT displayed significantly smaller RMSestimate than TSL and ATT. In 2D detailed analysis, DIT exhibited significantly less deviations from the natural teeth compared to TSL and ATT. CONCLUSION: The proposed DL model successfully reconstructed the morphology of anterior teeth with various degrees of defects and achieved satisfactory accuracy. This approach provides a more reliable reference for prostheses design, resulting in enhanced accuracy in morphological restoration. CLINICAL SIGNIFICANCE: This DL model holds promise in assisting dentists and technicians in obtaining morphology templates that closely resemble the original shape of the defective teeth. These customized templates serve as a foundation for enhancing the efficiency and precision of digital restorative design for defective teeth.


Assuntos
Desenho Assistido por Computador , Aprendizado Profundo , Planejamento de Prótese Dentária , Incisivo , Redes Neurais de Computação , Humanos , Incisivo/anatomia & histologia , Planejamento de Prótese Dentária/métodos , Modelos Dentários , Maxila/anatomia & histologia
12.
Surg Radiol Anat ; 46(5): 635-643, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38517513

RESUMO

PURPOSE: Cone-beam computed tomography (CBCT) was used in this study for evaluating the diameter, prevalence, spatial location, and risk factors of the accessory canal (AC) of the canalis sinuosus. METHODS: A comprehensive assessment of the incidence rate, diameter, three-dimensional (3D) spatial location, and direction of travel of AC was performed on 1003 CBCT images. The CBCT data were used to reconstruct a 3D model of the maxilla to determine the alveolar bone volume. The obtained data were further analyzed and processed. RESULTS: AC was present in 50.1% of images. Male patients more frequently had ACs than female patients did (P < 0.01) and was positively correlated with the maxillary alveolar bone volume (P < 0.001, OR 1.532). Age or nasopalatine canal diameter were not significantly associated with the occurrence of AC (P > 0.05). Among the 502 patients with AC, AC was present on the left side, right side, and bilaterally in 189, 98, and 215, respectively. The maximum number of ACs observed per individual was eight. The average AC diameter was 0.89 ± 0.26 mm (minimum, 0.5 mm; maximum, 2.02 mm). CONCLUSIONS: As the prevalence of AC and its trajectory display considerable variation among individuals, surgeons must consider the possibility of the presence of AC when devising surgical plans involving the anterior maxillary region.


Assuntos
Variação Anatômica , Tomografia Computadorizada de Feixe Cônico , Imageamento Tridimensional , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Fatores de Risco , Idoso , Adolescente , Adulto Jovem , Maxila/diagnóstico por imagem , Maxila/anatomia & histologia , Idoso de 80 Anos ou mais , Criança , Estudos Retrospectivos
13.
J Anat ; 244(6): 977-994, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38293709

RESUMO

Morphological studies typically avoid using osteological samples that derive from captive animals because it is assumed that their morphology is not representative of wild populations. Rearing environments indeed differ between wild and captive individuals. For example, mechanical properties of the diets provided to captive animals can be drastically different from the food present in their natural habitats, which could impact cranial morphology and dental health. Here, we examine morphological differences in the maxillae of wild versus captive chimpanzees (Pan troglodytes) given the prominence of this species in comparative samples used in human evolution research and the key role of the maxilla in such studies. Size and shape were analysed using three-dimensional geometric morphometric methods based on computed tomography scans of 94 wild and 30 captive specimens. Captive individuals have on average larger and more asymmetrical maxillae than wild chimpanzees, and significant differences are present in their maxillary shapes. A large proportion of these shape differences are attributable to static allometry, but wild and captive specimens still differ significantly from each other after allometric size adjustment of the shape data. Levels of shape variation are higher in the captive group, while the degree of size variation is likely similar in our two samples. Results are discussed in the context of ontogenetic growth trajectories, changes in dietary texture, an altered social environment, and generational differences. Additionally, sample simulations show that size and shape differences between chimpanzees and bonobos (Pan paniscus) are exaggerated when part of the wild sample is replaced with captive chimpanzees. Overall, this study confirms that maxillae of captive chimpanzees should not be included in morphological or taxonomic analyses when the objective is to characterise the species.


Assuntos
Maxila , Pan troglodytes , Animais , Pan troglodytes/anatomia & histologia , Maxila/anatomia & histologia , Maxila/diagnóstico por imagem , Masculino , Feminino , Animais Selvagens/anatomia & histologia , Tomografia Computadorizada por Raios X , Animais de Zoológico/anatomia & histologia
14.
Anat Rec (Hoboken) ; 307(4): 1421-1441, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38071453

RESUMO

Libognathus sheddi, a leptopleuronine procolophonid from the Upper Triassic Cooper Canyon Formation, Dockum Group, West Texas, was based on an isolated left dentary and partial coronoid. New material referable to Libognathus sheddi, from the Cooper Canyon Formation, provides new information on the cranial anatomy. This new cranial material includes the antorbital portion of a skull, a left maxilla and premaxilla, quadratojugals, and dentaries, including intact tooth rows in the upper and lower jaws. Libognathus shows autapomorphies including; dentary deep with ventral margin oblique to tooth row immediately from the symphysis at ≥23°; anterior projecting coronoid contacting the lingual surface of the dentary underlying the last two dentary teeth; reduced contact between the lacrimal and the nasal; suborbital foramen formed by the maxilla and ectopterygoid, excluding the palatine; a posterior supralabial foramen shared by the maxilla and jugal; a Y-shaped antorbital pillar formed by the palatine, and massive orbitonasale and facial foramina (shared with unnamed southwest USA leptopleuronines). Phylogenetic analysis indicates that Libognathus is a highly derived leptopleuronine procolophonid, closely related to Hypsognathus fenneri and other southwest USA Revueltian leptopleuronines, which fall out as sister taxa to Hypsognathus, a relationship supported by a maxillary dentition restricted anterior to the orbital margin, a possibly synapomorphic orbitonasale septum in the form of an "antorbital pillar" created by the palatine, an anteroventral process of the jugal, and the presence of a small diastema between the first dentary tooth and the more posterior dentition. Libognathus exhibits a possible ankylosed protothecodont tooth implantation with frequent replacement, differing from some other proposed procolophonid implantation and replacement models. Chinle Formation and Dockum Group leptopleuronines are restricted to the Revueltian teilzone/holochronozone, making them possible Revueltian index taxa.


Assuntos
Fósseis , Crânio , Filogenia , Texas , Crânio/anatomia & histologia , Maxila/anatomia & histologia
15.
Orthod Craniofac Res ; 27(1): 55-63, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37313756

RESUMO

INTRODUCTION: Palatal displacement of maxillary anterior teeth is common in clinical practice. Previous studies have reported that the labial bone around palatally-displaced incisors is thinner than that around normally-placed teeth. Therefore, it is necessary to elucidate alveolar bone changes after alignment to guide orthodontic treatment. In this study, we investigated the alveolar bone changes around palatally-displaced maxillary lateral incisors before and after treatment, and the effects of extraction and age using cone-beam computed tomography. METHODS: In this retrospective study, 55 patients with unilateral palatally-displaced maxillary lateral incisors were included. Three-dimensional alveolar bone changes were measured at three levels (25%, 50% and 75% of the root length) using cone-beam computed tomography. Group comparisons were made between displaced and control teeth, extraction and non-extraction groups, and adult and minor groups. RESULTS: After orthodontic treatment, labiopalatal and palatal alveolar bone widths decreased at all measured levels. Labial alveolar bone width increased significantly at P25, but decreased at P75. Concavity decreased, while tooth-axis angle, tooth length, B-CEJ and P-CEJ increased. Changes in LB and LP at P75, B-CEJ and P-CEJ were statistically significant. After treatment, the tooth-axis angle on the PD side increased by 9.46°. The change in tooth-axis angle on the PD side was significantly smaller, and LB and LP decreased more at P75, in the extraction group. CONCLUSIONS: Compared to the control teeth, alveolar bone thickness and height for the displaced teeth decreased more significantly after treatment. Tooth extraction and age also influenced alveolar bone changes.


Assuntos
Incisivo , Má Oclusão , Adulto , Humanos , Incisivo/diagnóstico por imagem , Incisivo/anatomia & histologia , Estudos Retrospectivos , Maxila/diagnóstico por imagem , Maxila/anatomia & histologia , Tomografia Computadorizada de Feixe Cônico/métodos
16.
J Anat ; 244(1): 42-62, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37737476

RESUMO

Sturgeons belong to the family Acipenseridae, the most species-rich extant family of Acipenseriformes, a basal actinopterygian group of key importance in assessing the early radiations of the actinopterygians. At the same time, acipenseriforms display unique specializations in the morphology of the snout and jaws which make them a valuable model for studying evolutionary novelties. However, despite a long history of research, the homologies of the snout and the mandibular arch of acipenseriforms remain uncertain preventing further studies on the evolutionary origin of their unique snout and jaw structure, and in particular, of the upper jaw symphysis, the key apomorphy of the group and the preoral snout. In the present study, a detailed description of the upper jaw morphology and development in sturgeons is provided in order to address its composition in terms of the common actinopterygian archetype. Based on the obtained results, the upper jaw of acipenseriforms is assumed to have lost the autopalatine portion, which most likely is represented by the separate cartilages supporting the tentacles. Also, the conventional interpretation of the sturgeon's maxilla as dermopalatine is rejected on the grounds of this bone structure and development. Paedomorphosis is proposed to be the most likely mechanism explaining the evolutionary origin of the upper jaw symphysis and supposed modifications of the snout in sturgeons.


Assuntos
Arcada Osseodentária , Maxila , Animais , Maxila/anatomia & histologia , Arcada Osseodentária/anatomia & histologia , Evolução Biológica , Peixes/anatomia & histologia , Articulações , Cartilagem
17.
Odontology ; 112(2): 552-561, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37907818

RESUMO

The objective of this study is to use a deep-learning model based on CNN architecture to detect the second mesiobuccal (MB2) canals, which are seen as a variation in maxillary molars root canals. In the current study, 922 axial sections from 153 patients' cone beam computed tomography (CBCT) images were used. The segmentation method was employed to identify the MB2 canals in maxillary molars that had not previously had endodontic treatment. Labeled images were divided into training (80%), validation (10%) and testing (10%) groups. The artificial intelligence (AI) model was trained using the You Only Look Once v5 (YOLOv5x) architecture with 500 epochs and a learning rate of 0.01. Confusion matrix and receiver-operating characteristic (ROC) analysis were used in the statistical evaluation of the results. The sensitivity of the MB2 canal segmentation model was 0.92, the precision was 0.83, and the F1 score value was 0.87. The area under the curve (AUC) in the ROC graph of the model was 0.84. The mAP value at 0.5 inter-over union (IoU) was found as 0.88. The deep-learning algorithm used showed a high success in the detection of the MB2 canal. The success of the endodontic treatment can be increased and clinicians' time can be preserved using the newly created artificial intelligence-based models to identify variations in root canal anatomy before the treatment.


Assuntos
Inteligência Artificial , Cavidade Pulpar , Humanos , Cavidade Pulpar/diagnóstico por imagem , Raiz Dentária , Maxila/anatomia & histologia , Tomografia Computadorizada de Feixe Cônico/métodos
18.
Ann Anat ; 252: 152193, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38016625

RESUMO

BACKGROUND: Sufficient alveolar housing is fundamental to ensure the favorable prognosis of autotransplanted teeth. However, little is known about the alveolar ridge profiles of the anterior maxilla in children. Therefore, this study aimed to investigate the alveolar ridge profiles of the anterior maxilla in growing children. METHODS: A total of 169 Korean children aged 10-13 years old were included in this retrospective study. Demographic data and cone-beam computed tomography scans of 244 maxillary central incisors were collected. For each tooth, the alveolar ridge thickness was determined at 1-, 3-, and 5-mm levels below the cemento-enamel junction. The alveolar process height and labial concavity were also evaluated. Statistical analyses were performed to evaluate differences according to age and sex. RESULTS: The alveolar ridge thickness did not differ according to age. The alveolar ridge thickness in males was significantly greater than that in females among those aged 10 and 11 years. The average alveolar process height was 17.43 ± 2.22 mm. The alveolar process height hardly changed with age from 10-13 years, whereas the alveolar process height of males was significantly greater compared with that of females among those aged 10 years. The labial concavity was approximately 150˚, with no significant differences between age and sex. CONCLUSIONS: Within the limits of this study, the anatomy of the alveolar ridge in the maxillary central incisors showed sufficient capacity as a recipient site for autotransplantation using mandibular premolars, especially in males. These findings serve as a valuable resource for facilitating autotransplantation in children.


Assuntos
Processo Alveolar , Incisivo , Masculino , Feminino , Criança , Humanos , Adolescente , Estudos Retrospectivos , Incisivo/diagnóstico por imagem , Incisivo/anatomia & histologia , Transplante Autólogo , Processo Alveolar/diagnóstico por imagem , Processo Alveolar/cirurgia , Processo Alveolar/anatomia & histologia , Maxila/diagnóstico por imagem , Maxila/anatomia & histologia , Tomografia Computadorizada de Feixe Cônico/métodos
19.
Int J Legal Med ; 138(3): 1117-1137, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38010514

RESUMO

INTRODUCTION: The anterior nasal spine is a pointed, midline projection of the maxilla. This bony structure dictates the overlying soft tissues providing the phenotypic features of the nose and upper lip and determines the differences in the mid-face morphology. Little data is available on the metric features of the Anterior nasal spine (ANS). This study aimed to perform metric evaluations of the ANS of white and black South African males and females to ascertain if morphological variations exist and if the differences are viable for the use in sex and population identification. MATERIALS AND METHODS: The sample included 100 CBCT images for each population and sex group. Linear and angular measurements of the ANS were recorded in both the sagittal and axial planes. RESULTS: Classification decision trees (pruned) were fitted to ascertain the relationship between population group, sex and the ANS measurements including and excluding age. For population group, all the ANS measurements were statistically significant for females but in males, all the ANS measurements were significant when performed individually. However, when fitted to the classification tree, Sagittal 2 did not show any statistical significance. When considering sex, only 2 of the ANS measurements (Sagittal 2 and Axial 1) were found to be significant. The results did not differ significantly when comparing the decision trees including and excluding age. CONCLUSIONS: White South African individuals presented with a longer ANS that produced a more acute angle whereas black South African individuals presented with a shorter ANS and a more obtuse angle. Additionally, males presented with a longer ANS compared to females. ANS measurements were found to be more relevant for population discernment than for sex.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Grupos Populacionais , Masculino , Feminino , Humanos , África do Sul , Tomografia Computadorizada de Feixe Cônico/métodos , Maxila/anatomia & histologia , Nariz
20.
Clin Oral Investig ; 28(1): 63, 2023 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-38158507

RESUMO

OBJECTIVES: We aimed to determine safe areas to apply miniscrews in the interradicular region of the maxilla and mandible in individuals with various sagittal skeletal malocclusions. MATERIALS AND METHODS: Cone beam-computed tomography images of 159 individuals were used. Individuals were divided into three groups: Class I, Class II, and Class III. In the sagittal plane, 3-6-9-mm apical sections were determined from the alveolar crest apex. The buccal cortical bone thickness, interradicular distance, and buccolingual bone distances were measured. RESULTS: In the buccal cortical bone thickness, we observed statistically significant differences between the classes except for the 1-1 region in the maxilla and all regions and sections in the mandible (p < 0.05). The differences in the buccolingual bone distance between classes were statistically significant, except for the 3-mm and 6-mm sections in the 3-4 and 4-5 regions of the maxilla, the 9-mm sections in the 1-2 and 2-3 regions, the 6-mm and 9-mm sections in the 3-4 region, and the 6-mm section in the 4-5 regions of the mandible (p < 0.05). The differences in the interradicular bone distance were statistically significant between the classes in all regions and sections of the mandible except the 6-mm sections in the 1-2 region and in all sections of the maxilla except the 6-mm sections in the 3-4 region (p < 0.05). CONCLUSIONS: We observed significant differences in the buccal cortical bone thickness, interradicular bone distance, and buccolingual bone distance among individuals. CLINICAL RELEVANCE: Understanding the anatomy of interradicular regions and preventing complications.


Assuntos
Má Oclusão , Tomografia Computadorizada de Feixe Cônico Espiral , Humanos , Mandíbula/diagnóstico por imagem , Mandíbula/anatomia & histologia , Processo Alveolar/diagnóstico por imagem , Maxila/diagnóstico por imagem , Maxila/anatomia & histologia , Tomografia Computadorizada de Feixe Cônico/métodos
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