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1.
Acta Odontol Latinoam ; 33(1): 14-21, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32621594

RESUMO

The aim of this study was to evaluate the influence of spatial resolution (line pairs per millimetre - lp/mm) on the diagnosis of simulated external root resorption (ERR) in multi-rooted teeth by using digital periapical radiography. Forty human mandibular molars (80 roots) were used. The roots were divided into the following groups (n = 10): control without root filling (WORF), control with root filling (WRF), small ERRWORF, small ERR-WRF, moderate ERR-WORF, moderate ERR-WRF, extensive ERR-WORF and extensive ERR-WRF. Four digital radiographs (phosphor storage plates - PSP system) were taken of each tooth in three angulations. The PSPs were scanned with 10, 20, 25 and 40 lp/mm. All images were assessed by three endodontists who used a five-point scale for presence and absence of ERR and classified its location (cervical, middle or apical third). ROC curves and one-way ANOVA were performed (p < 0.01). Diagnosis of ERR in nonroot-filled teeth showed higher values of sensitivity for 20 lp/mm and higher values of both specificity and accuracy for 40 lp/mm. In root-filled teeth, sensitivity and accuracy were higher for 25 lp/mm and spatial resolution had no influence on specificity. The best resolution for diagnosis of small and extensive ERR was 25 lp/mm, whereas for moderate ERR, it was 40 lp/mm. Cervical ERR was the most difficult to diagnose, regardless of the spatial resolution. Higher spatial resolutions have improved the radiographic diagnosis of simulated ERR in multi-rooted teeth and this should be considered when performing digital radiographs.


Assuntos
Dente Molar/diagnóstico por imagem , Radiografia Dentária Digital/métodos , Reabsorção da Raiz/diagnóstico por imagem , Tomografia Computadorizada de Feixe Cônico , Humanos , Obturação do Canal Radicular
2.
J Appl Oral Sci ; 28: e20190628, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32520078

RESUMO

OBJECTIVE: The study of dental development in individuals born with cleft lip and palate (CLP) serves to determine when orthodontic intervention should start. To evaluate the permanent second molar development in children born with cleft lip and palate according to Demirjian's and Nolla's methods. METHODOLOGY: Out of a total of 513 digital panoramic radiographs, 113 pairs of children aged 3 to 16 years were selected. The exams were from children born with or without cleft lip and palate, of the same sex, with an age difference of up to 30 days. The images were analyzed by three examiners and reliability was checked through intra-examiner agreement by the Kappa test. The data were analyzed by Wilcoxon's and Mann-Whitney tests according to each dataset. RESULTS: The findings indicated delayed development of the permanent second molars in children with CLP (P<0.001). The development of the right permanent second molar was delayed compared to the left molar in children with CLP. Moreover, mandibular teeth showed significantly earlier development than maxillary teeth in both the case and control groups. There was no significant difference in the development of permanent second molars between sexes. CONCLUSION: Children with CLP presented delay in the development of permanent second molars.


Assuntos
Fenda Labial/fisiopatologia , Fissura Palatina/fisiopatologia , Dentição Permanente , Dente Molar/crescimento & desenvolvimento , Adolescente , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Dente Molar/diagnóstico por imagem , Valores de Referência , Fatores Sexuais , Estatísticas não Paramétricas
3.
J Appl Oral Sci ; 28: e20190168, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32236352

RESUMO

INTRODUCTION: Isthmuses are reported as common anatomic complexities in teeth often associated with failures in endodontic treatment. They should be considered before starting treatment and a preoperative computed tomography scan (CT) may demonstrate these complexities. OBJECTIVE: To assess the diagnostic value of the highest resolution settings of a cone-beam CT (CBCT) system in identifying and measuring apical isthmuses, using micro-CT as reference. METHODOLOGY: After micro-CT scanning, 40 humans' lower first molars with isthmuses in the apical-3 mm of mesial roots were scanned by the highest resolution settings of the New Generation i-Cat ® CBCT equipment. Two blinded observers recorded the detection of isthmuses in CBCT scans. The lengths of isthmuses were compared between micro-CT and CBCT to assess the diagnostic value of CBCT. Quantitative data for sensitivity were represented as percentages (95% confidence interval). The Bland-Altman method was used to assess differences between gold standard lengths (micro-CT) and CBCT lengths. RESULTS: BCT demonstrated 30 positive findings, representing sensitivity for isthmus identification of 75% (95% CI=0.4114-1.1364). Differences between the lengths in micro-CT (1.99±0.40 mm) and CBCT (1.53±0.41 mm) were significant (p<0.0001). CONCLUSION: The CBCT device used presented limited diagnostic value in the identification and measurement of apical isthmuses in the mesial roots of lower molars. In some cases, the actual anatomy of the apical root canal may not be completely delineated in this type of CBCT system, even using the highest resolution settings.


Assuntos
Tomografia Computadorizada de Feixe Cônico/métodos , Ápice Dentário/anatomia & histologia , Ápice Dentário/diagnóstico por imagem , Raiz Dentária/anatomia & histologia , Raiz Dentária/diagnóstico por imagem , Análise de Variância , Humanos , Dente Molar/anatomia & histologia , Dente Molar/diagnóstico por imagem , Variações Dependentes do Observador , Tamanho do Órgão , Valores de Referência , Reprodutibilidade dos Testes , Tratamento do Canal Radicular/métodos , Sensibilidade e Especificidade
4.
Niger J Clin Pract ; 23(2): 232-239, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32031099

RESUMO

Aims: To evaluate the prevalence, correlation, and differences of C-shaped canal morphology in mandibular premolars and molars by means of cone-beam computed tomography (CBCT). Materials and Methods: A total of 1433 mandibular premolars and molars CBCT scans from the Saudi population were evaluated. Axial sections of the roots were acquired at coronal, middle, and apical levels to evaluate C-shaped canals types. The prevalence, correlation, differences of C-shaped canals, bilateral/unilateral presence, gender differences, and location of external grooves on roots were assessed. Results: The prevalence of C-shaped canals in the first premolars was 1.5%, 0.80% in second premolars and 7.9% in second molars, whereas C-shaped canals were absent in first molars. No correlation was found between the presence of C-shaped canals within premolars and molars and between the two groups in the same individual. Both premolars and molars exhibited different types of C-shaped canals, C2 being predominant in premolars and C3 in second molars. Longitudinal external grooves were mostly located on mesiolingual (ML) surface in premolars and lingual in molars. Females showed more prevalence of C-shaped canals in second molars and no differences in premolars. Bilateral symmetry and unilateral presence in premolars and second molars were not significant. Conclusions: Although the prevalence of C-shaped canals is significantly higher in mandibular second molars, they are also found in mandibular premolars but in small percentages. No significant differences were found between both genders and both sides. Since they exhibit unpredictable morphology and differences across the root length, the use of small field CBCT is recommended when such anatomy is presented in a tooth indicated for root canal treatment for better management.


Assuntos
Dente Pré-Molar/diagnóstico por imagem , Tomografia Computadorizada de Feixe Cônico/métodos , Cavidade Pulpar/diagnóstico por imagem , Mandíbula/diagnóstico por imagem , Dente Molar/diagnóstico por imagem , Raiz Dentária/diagnóstico por imagem , Adolescente , Adulto , Dente Pré-Molar/anatomia & histologia , Estudos Transversais , Cavidade Pulpar/anatomia & histologia , Feminino , Humanos , Masculino , Mandíbula/anatomia & histologia , Pessoa de Meia-Idade , Dente Molar/anatomia & histologia , Prevalência , Arábia Saudita , Fatores Sexuais , Raiz Dentária/anatomia & histologia , Adulto Jovem
5.
Lasers Med Sci ; 35(1): 213-219, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31342201

RESUMO

To investigate the prevalence of different patterns of cemento-enamel junction (CEJ) morphology under swept-source optical coherence tomography (SS-OCT). One hundred extracted human teeth were used consisting of incisors, premolars, and molars. Each sample was observed for every 500 µm circumferentially along CEJ and OCT images of the pattern were noted. Microscopic observations were done for the representative sample using confocal laser scanning microscope (CLSM) and transmission electron microscope (TEM). The OCT images exhibited four CEJ patterns: edge-to-edge (type I), exposed dentin (type II), cementum overlapping enamel (type III), and enamel overlapping cementum (type IV). The prevalence of CEJ patterns was further statistically considered for mesial, distal, buccal, and lingual surfaces. The real-time imaging by SS-OCT instantly determined CEJ morphology. CLSM and TEM observation revealed morphological features along CEJ, which corresponded to OCT images of CEJ anatomy. OCT results showed 56.8% of type I pattern predominantly found on proximal surfaces, followed by 36.5% of type II pattern on buccal and lingual surface, 6.4% of type III pattern, and 0.3% of type IV pattern. There was a significant difference in prevalence of CEJ patterns among different types of teeth, but there was no statistically significant difference among the four surfaces in each type of teeth. OCT is a non-invasive diagnostic tool to examine the CEJ patterns along the entire circumference. OCT observation revealed even minor dentin exposure that would need clinical and home procedures to prevent any symptoms.


Assuntos
Esmalte Dentário/anatomia & histologia , Esmalte Dentário/diagnóstico por imagem , Tomografia de Coerência Óptica , Colo do Dente/anatomia & histologia , Colo do Dente/diagnóstico por imagem , Dente Pré-Molar/anatomia & histologia , Dente Pré-Molar/diagnóstico por imagem , Humanos , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Dente Molar/anatomia & histologia , Dente Molar/diagnóstico por imagem
6.
Gen Dent ; 68(1): 66-71, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31859666

RESUMO

Knowledge of the anatomical relationships between the maxillary sinus (MS) and posterior teeth is important to prevent complications when endodontic or oral surgical procedures are performed. The aim of this study was to evaluate the relationships between the root apices of maxillary posterior teeth and the MS floor. Three oral radiologists evaluated 851 posterior teeth (1969 roots) imaged with cone beam computed tomography. The roots were analyzed individually in parasagittal sections, on which the most superior point of the apex was observed. A qualitative evaluation was performed, and each root was assigned a proximity score: 1, root invaginating the MS; 2, root in close contact with the MS floor; 3, root with no relationship with the MS; and 4, root with a measurable proximity to the MS. For roots classified as score 4, the distance to the MS floor was measured (quantitative analysis). Student t tests, 1-way analysis of variance, and simple linear regression analysis were performed (P < 0.05). The qualitative analysis revealed that the mesiobuccal root of the second molar had a pronounced proximity to the MS. The quantitative analysis revealed no differences in distance to the MS between right and left posterior teeth or between the different roots of the same tooth. In relation to the MS, the second molar was positioned closest, followed by the first molar, second premolar, and first premolar. Except for the comparison between mean distances of the second premolar and first molar (P = 0.11), the differences between groups of teeth were statistically significant (P < 0.05). Simple linear regression analysis showed that the more posterior the tooth was in relation to the midline, the shorter the mean distance from the root apex to the MS floor (P < 0.05). The mesiobuccal roots of second molars were closest to the MS. Second molars exhibited the shortest distances between their root apices and the MS and the greatest number of roots that were invaginating or in close contact with the MS. Therefore, second molars require special attention when endodontic or oral surgical approaches involve those regions.


Assuntos
Tomografia Computadorizada de Feixe Cônico/métodos , Maxila , Seio Maxilar , Humanos , Processamento de Imagem Assistida por Computador , Maxila/anatomia & histologia , Seio Maxilar/anatomia & histologia , Seio Maxilar/diagnóstico por imagem , Dente Molar/anatomia & histologia , Dente Molar/diagnóstico por imagem , Raiz Dentária/anatomia & histologia , Raiz Dentária/diagnóstico por imagem
7.
Scanning ; 2019: 1289570, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31741697

RESUMO

The aim of this study was to evaluate the accuracy of two intraoral scanners used in the dental office. A molar fixed in a typodont was prepared for a ceramic onlay. The preparation was scanned using a high-resolution scanner (reference scanner) and saved as stereolithography (STL) format. The prepared resin molar was scanned again using the intraoral scanners, and all the scans were saved as well in STL format. All STL files were compared using metrology software (Geomagic Control X). Overlapping the meshes allowed the assessment of the scans in terms of trueness and precision. Based on the results of this study, the differences of trueness and precision between the intraoral scanners were minimal.


Assuntos
Armazenamento e Recuperação da Informação/normas , Microscopia Confocal/métodos , Dente Molar/diagnóstico por imagem , Tomografia de Coerência Óptica/métodos , Cerâmica/química , Humanos , Restaurações Intracoronárias/métodos , Lasers , Microscopia Confocal/instrumentação , Microscopia Confocal/normas , Resinas Sintéticas/química , Software , Tomografia de Coerência Óptica/instrumentação , Tomografia de Coerência Óptica/normas
8.
J Endod ; 45(12): 1472-1478, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31648800

RESUMO

INTRODUCTION: Apical surgery is frequently indicated in maxillary first molars. Occasionally, a vascular anastomosis in the lateral maxillary sinus wall can be observed during surgery. The aim of this study was to examine the distance between the vascular bone channel (VBC) and the root apices of maxillary first molars using cone-beam computed tomographic imaging. METHODS: Cone-beam computed tomographic images of 104 maxillary first molars were oriented in the coronal plane to evaluate the distance between the roots and the VBC. The measurements were only recorded in relation to the buccal roots. In addition, demographic parameters and further measurements such as the diameter of the VBC and the proximity to the periapical pathology were evaluated. RESULTS: A total of 210 VBCs were assessed. The mean distance from the VBC to the apices of the buccal roots of the maxillary first molars was 6.18 mm ± 3.84 mm. The VBC was mostly located intrasinusally (74.3%) and only rarely superficially (0.5%). The diameter of the VBC was on average 0.88 ± 0.32 mm. CONCLUSIONS: In this study, the VBC was usually found closer to the mesiobuccal than to the distobuccal root apex. During preparation of the access window, the existence of the VBC should be kept in mind because the mesiobuccal roots of maxillary first molars undergo apical surgery to the buccally positioned roots only.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Dente Molar , Seios Transversos , Humanos , Maxila , Seio Maxilar , Dente Molar/diagnóstico por imagem , Raiz Dentária , Seios Transversos/diagnóstico por imagem
9.
Medicine (Baltimore) ; 98(40): e17356, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31577730

RESUMO

Molar-incisor malformation (MIM) is a recently defined dental abnormality of molar root and incisors, and introduced as one of the causes of periapical and periodontal abscess. The purpose of this study was to investigate the clinical and radiological features of MIM, with special emphasis on various medical history. A total of 38 patients with MIM were included in this study. Radiographic features and clinical data, including medical history, chief complaint, associated complications, treatment, and prognosis, were retrospectively investigated. On radiographs, the affected molars showed short, slender, underdeveloped roots and constricted pulp chambers. All affected incisors and canines exhibited dilacerated short roots, wedge-shaped defect on the cervical part of the crown. Complications included periodontal bone loss (52.6%), endodontic lesion (50.0%), and endodontic-periodontal lesion (28.9%). The medical histories of the patients with MIM indicate that almost all (94.7%) were hospitalized due to problems during the neonatal period. MIM may cause various dental problems, such as periapical and periodontal abscess and early loss of the affected teeth. The early diagnosis of MIM on radiographs and appropriate treatment will contribute to a favorable prognosis, especially for young and adolescent patients.


Assuntos
Incisivo/diagnóstico por imagem , Incisivo/patologia , Dente Molar/diagnóstico por imagem , Dente Molar/patologia , Anormalidades Dentárias/diagnóstico por imagem , Anormalidades Dentárias/patologia , Adolescente , Perda do Osso Alveolar/etiologia , Criança , Pré-Escolar , Cavidade Pulpar/diagnóstico por imagem , Cavidade Pulpar/patologia , Feminino , Humanos , Masculino , Radiografia Dentária , Estudos Retrospectivos , Anormalidades Dentárias/complicações , Anormalidades Dentárias/diagnóstico , Raiz Dentária/diagnóstico por imagem , Raiz Dentária/patologia , Adulto Jovem
10.
Am J Orthod Dentofacial Orthop ; 156(4): 493-501, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31582121

RESUMO

INTRODUCTION: The purpose of this research was to evaluate dental compensation in facial asymmetry and its correlation with skeletal variables using cone-beam computed tomography. METHODS: Sixty adult patients were retrospectively divided into asymmetry (mean age, 21.8 ± 5.4 years) and symmetry groups (mean age, 28.1 ± 4.1 years); both groups comprised 30 patients. Independent and paired t tests were used for comparisons between the asymmetry and symmetry groups and between deviated (Dv) and nondeviated (NDv) sides of the asymmetry group, respectively. Pearson correlation between dental and skeletal variables was performed. RESULTS: The mean value of menton deviation was 9.4 mm in the asymmetry group. Compared with the symmetry group, the direction and amount of dental compensation of the asymmetry group were as follows: 2.5-mm extrusion of the maxillary first molar (UM6) at NDv (P <0.05); 1.8-mm higher position of the mandibular canine (LC) from the mandibular horizontal plane using mental foramen (MHP_mf) at NDv (P <0.05); 6°-more buccoversion of UM6 at Dv; 3.7°-more linguoversion of UM6 at NDv; 4.8°-more buccoversion of the maxillary canine (UC) at Dv; 4.9°-more buccoversion of the mandibular molar (LM6) at NDv; and 2.6°-more linguoversion of LC at Dv. Dental compensation correlated or marginally correlated with skeletal variables of the deviated mandible. CONCLUSIONS: Dental compensations, extrusion of the maxillary molars on the NDv, and buccal tipping of the maxillary teeth and lingual tipping of the mandibular teeth on the Dv, were observed. The mandibular body length was associated with linguoversion of the mandibular molars on the Dv. The ramal inclination was related to the extrusion of the maxillary molars on the NDv.


Assuntos
Cefalometria/métodos , Tomografia Computadorizada de Feixe Cônico/métodos , Assimetria Facial/diagnóstico por imagem , Má Oclusão/diagnóstico por imagem , Dente Molar/diagnóstico por imagem , Adolescente , Adulto , Estética Dentária , Assimetria Facial/fisiopatologia , Feminino , Humanos , Imageamento Tridimensional/métodos , Masculino , Má Oclusão/fisiopatologia , Pessoa de Meia-Idade , Dente Molar/fisiopatologia , Estudos Retrospectivos
11.
Am J Orthod Dentofacial Orthop ; 156(3): 365-374, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31474266

RESUMO

INTRODUCTION: We sought the 3-dimensional (3D) zone of the center of resistance (ZCR) of mandibular posterior teeth groups (group 1: first molar; group 2: both molars; group 3: both molars and second premolar; group 4: both molars and both premolars) with the use of 3D finite element analysis. METHODS: 3D finite element models comprised the mandibular posterior teeth, periodontal ligament, and alveolar bone. In the symmetric bilateral model, a 100-g midline force was applied on a median sagittal plane at 0.1-mm intervals to determine the anteroposterior and vertical positions of the ZCR (where the applied force induced translation). The most reliable buccolingual position of the ZCR was then determined in the unilateral model. The combination of the anteroposterior, vertical, and buccolingual positions was defined as the ZCR. RESULTS: The ZCRs of groups 1-4 were, respectively, 0.48, 0.46, 0.50, and 0.53 of the mandibular first molar root length from the alveolar crest level and located slightly distobuccally at anteroposterior ratios of 2:3.0, 2:2.3, 2:2.4, and 2:2.5 to each sectional arch length and at buccolingual ratios of 2:1.5, 2:1.1, 2:1.6, and 2:2.4 to the first molar's buccolingual width. CONCLUSIONS: The ZCR can be a useful reference for 3D movement planning of mandibular posterior teeth or segments.


Assuntos
Imageamento Tridimensional/métodos , Mandíbula/anatomia & histologia , Mandíbula/diagnóstico por imagem , Dente/anatomia & histologia , Dente/diagnóstico por imagem , Processo Alveolar/anatomia & histologia , Processo Alveolar/diagnóstico por imagem , Dente Pré-Molar/anatomia & histologia , Dente Pré-Molar/diagnóstico por imagem , Arco Dental , Modelos Dentários , Análise de Elementos Finitos , Humanos , Dente Molar/anatomia & histologia , Dente Molar/diagnóstico por imagem , Ortodontia Corretiva , Ligamento Periodontal/anatomia & histologia , Ligamento Periodontal/diagnóstico por imagem , Técnicas de Movimentação Dentária
12.
J Pak Med Assoc ; 69(8): 1084-1089, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31431757

RESUMO

OBJECTIVE: To evaluate the root canal morphology of permanent mandibular first molars using Cone Beam Computed Tomography. METHODS: The retrospective study was done at Aga Khan University Hospital, Karachi, and comprised medical records of patients who visited the dental clinics from December 2016 to March 2017. Mandibular first permanent molars were evaluated on Cone Beam Computed Tomography images. Frequency distribution of Vertucci's classification was determined, and so was the association between Vertucci's classifications and gender. SPSS 20 was used for data analysis. RESULTS: A total of 142 mandibular first permanent molars were evaluated on 78 Cone Beam Computed Tomography images. The most common Vertucci's classification was Type IV for mesial root 86(60.56%) and Type I for distal root 63(44%). There was no difference in the two genders for root canal morphology (p>0.05). CONCLUSIONS: Type IV Vertucci's were prevalent in the mesial root and Type I were common in the distal root of permanent mandibular first molars.


Assuntos
Cavidade Pulpar/diagnóstico por imagem , Mandíbula/diagnóstico por imagem , Dente Molar/diagnóstico por imagem , Raiz Dentária/diagnóstico por imagem , Adolescente , Adulto , Tomografia Computadorizada de Feixe Cônico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Paquistão , Estudos Retrospectivos , Adulto Jovem
13.
Niger J Clin Pract ; 22(8): 1091-1098, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31417052

RESUMO

Aims: Our aim was to compare three different voxel sizes of CBCT images for the determination of residual filling material volume in root canals when compared with micro CT. Material and Methods: Forty-two root canals of 14 extracted human maxillary molar teeth were retreated by using ProFile® instruments. Images were obtained after retreatment by using ProMax 3D Max CBCT at 3 different voxel sizes (1) High resolution (0.1 mm); (2) High definition (0.15 mm); and (3) Normal resolution (0.2 mm). Two observers measured volumes of residual filling materials in exported CBCT images by means of 3D Doctor Software. Micro CT measurements were served as gold standard. Mann-Whitney U test and Wilcoxon Test were used for the comparison of CBCT and micro CT measurements. Statistical significance was set at P < 0.05. Results: No statistically differences were found between the two observers for all measurements (P > 0.05). There were no significant differences among different CBCT voxel sizes used (0.1 mm, 0.15 mm, and 0.2 mm) (P > 0.05). The Spearman correlation coefficients between CBCT at different voxel sizes significantly highly correlated with micro CT measurements for each observer (P < 0.05). Furthermore, no significant differences were found between the measurements obtained by the two observers in consideration to root canal location (P > 0.05). Conclusion: CBCT images may provide useful information in the volumetric assessment of the amount of residual filling material in root canals for retreatment procedures.


Assuntos
Cavidade Pulpar/diagnóstico por imagem , Dente Molar/diagnóstico por imagem , Dente Molar/cirurgia , Retratamento , Materiais Restauradores do Canal Radicular/química , Obturação do Canal Radicular/métodos , Tratamento do Canal Radicular/métodos , Tomografia Computadorizada de Feixe Cônico Espiral/métodos , Materiais Dentários , Humanos , Processamento de Imagem Assistida por Computador/métodos , Materiais Restauradores do Canal Radicular/uso terapêutico , Preparo de Canal Radicular/métodos , Microtomografia por Raio-X/métodos
14.
Am J Orthod Dentofacial Orthop ; 156(2): 178-185, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31375227

RESUMO

INTRODUCTION: This study aimed to identify significant factors affecting the spontaneous angular changes of impacted mandibular third molars as a result of second molar protraction. Temporary skeletal anchorage devices in the missing mandibular first molar (ML-6) or missing deciduous mandibular second molar (ML-E) with missing succedaneous premolar spaces provided traction. METHODS: Forty-one mandibular third molars of 34 patients (10 male and 24 female; mean age 18.3 ± 3.7 years) that erupted after second molar protraction were included in this study. They were classified into upright (U) and tilted (T) groups. Linear and angular measurements were performed at the time of treatment initiation (T1) and of ML-6 or ML-E space closure (T2). Regression analyses were used to identify significant factors related to third molar uprighting. RESULTS: Nolla stage (odds ratio [OR] 4.1), sex (OR 0.003 for male), third molar angulation at T1 (OR 1.1), missing tooth space (OR 0.006), rate of third molar eruption (OR 23.3), and rate of second molar protraction (OR 0.2) significantly affected third molar uprighting. Age, third molar angulation at T1, rate of third molar eruption, and rate of second molar protraction were significant factors for predicting third molar angulation at T2. CONCLUSIONS: Available space for third molar eruption before and after second molar protraction is not associated with uprighting of erupting third molars. Older patients whose third molars are in greater Nolla stage, are in a more upright position at T1, and have a greater eruption rate have a greater chance for third molar uprighting. Alternatively, an increase in second molar protraction rate results in mesial tipping of the third molars.


Assuntos
Má Oclusão/prevenção & controle , Má Oclusão/fisiopatologia , Mandíbula/fisiopatologia , Dente Serotino/fisiopatologia , Dente Impactado/fisiopatologia , Adolescente , Adulto , Pontos de Referência Anatômicos , Dente Pré-Molar , Feminino , Humanos , Masculino , Má Oclusão/diagnóstico por imagem , Mandíbula/anatomia & histologia , Mandíbula/diagnóstico por imagem , Dente Molar/anatomia & histologia , Dente Molar/diagnóstico por imagem , Dente Molar/fisiopatologia , Dente Serotino/anatomia & histologia , Dente Serotino/diagnóstico por imagem , Aparelhos Ortodônticos , Fechamento de Espaço Ortodôntico , Ortodontia Corretiva , Erupção Dentária , Dente Decíduo , Dente Impactado/complicações , Dente Impactado/diagnóstico por imagem , Adulto Jovem
15.
Am J Phys Anthropol ; 170(2): 260-274, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31381127

RESUMO

OBJECTIVES: Topographic estimates of dental relief are now commonly used to make dietary inferences from the teeth of extant and extinct primates. We thoroughly compared commonly used relief estimates in an effort to help researchers decide which variable best suits their objectives. MATERIALS AND METHODS: We combined a total of three datasets: five theoretical models built to compare the effect of tooth complexity and basin depth on relief estimates, a dataset of 110 lower molars of prosimians, and a dataset of 25 upper molars of apes. We investigated intra-mesh variation and tooth average relief, estimated from slope and three different relief indices, according to four criteria: (1) the ability to map relief on topographic maps, (2) the correlation with other relief estimates, (3) the ability to separate high-relief molars of folivores from deep-relief molars of insectivores in prosimians, and (4) the influence of surface complexity on relief estimates in apes. RESULTS: We found that polygon slope and relief index are linked by a mathematical relation. Tooth average slope and all relief indices are strongly correlated. In contrast, relief estimates are moderately correlated to cusp elevation. One relief index of four relief estimates had an excellent ability to separate high-relief from deep-relief molars in prosimians, whereas slope could not separate them. No significant effect of tooth complexity on dental relief could be detected in apes. CONCLUSIONS: Because slope and relief indices are highly correlated, it is strongly recommended not to combine them in multivariate analysis. Still, slope and relief indices show interesting differences in scaling, graphical representation, computation method, and ability to separate high-relief and deep-relief molars. Our results also suggest that slope and relief indices can vary independently of tooth complexity and are moderately affected by mean cusp elevation in apes.


Assuntos
Hominidae/anatomia & histologia , Imageamento Tridimensional/métodos , Dente Molar , Odontometria/métodos , Strepsirhini/anatomia & histologia , Animais , Antropologia Física , Modelos Estatísticos , Dente Molar/anatomia & histologia , Dente Molar/diagnóstico por imagem
16.
Microsc Res Tech ; 82(11): 1884-1890, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31400189

RESUMO

Determining surface topography of different tissues of the molar tooth with novel analytical methods has opened new horizons in dental surface measurements which characterize tooth surface quality in dentistry. Studying surface topological measurements and comparing surface morphology of hard tissue of the molar tooth are the ultimate goals of the present study. Ten molar teeth have been chosen for investigating their surface characteristics through image processing techniques. The power spectral density (PSD) and fast Fourier transform algorithms of every molar tooth containing enamel, dentin, and cementum have determined that the characterization of surface profiles is possible. As can be seen, PSD along with fractal dimensions leads to good results for teeth surface topography. Moreover, PSD angular plot assures appropriate description of surface.


Assuntos
Cemento Dentário/ultraestrutura , Esmalte Dentário/ultraestrutura , Dentina/ultraestrutura , Fractais , Dente Molar/ultraestrutura , Adulto , Cristalografia por Raios X , Análise de Fourier , Dureza/fisiologia , Humanos , Masculino , Microscopia de Força Atômica , Dente Molar/diagnóstico por imagem , Propriedades de Superfície
17.
Braz Oral Res ; 33: e082, 2019 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-31460608

RESUMO

The present study aimed to evaluate the internal configuration of the maxillary molars of a population from the Northeast region of Brazil. Cone-beam computed tomography (CBCT) exams from 512 patients (1501 teeth) were evaluated regarding the anatomical configuration of the root canal system, according to Vertucci's classification. The images were obtained using a Prexion 3D scanner operating at 90 kVp and 4 mA. The voxel size was 0.125 mm and the cut thickness was 1 mm. The images were then analyzed in the Prexion 3D Viewer software. The data were analyzed statistically by Pearson's chi-square test, with 5% of significance. The first and second molars presented three roots in 99.14% and 87.27% of the cases, respectively. In relation to the number of canals, the first and second molars had a significantly higher frequency of three and four root canals respectively, presenting a higher prevalence of types I and II (p < 0.001). The second mesiobuccal canal (MB2) was observed in 48.21% and 22.72% of the first and second molars, respectively (p < 0.001). The identification of the MB2 canal was greater in young and adult patients (p < 0.001), presenting a higher prevalence in male patients (p < 0.001). The internal configuration of the MB root was influenced by gender and by age, presenting a higher prevalence of the MB2 in male patients younger than 50 years of age.


Assuntos
Tomografia Computadorizada de Feixe Cônico/métodos , Cavidade Pulpar/anatomia & histologia , Cavidade Pulpar/diagnóstico por imagem , Dente Molar/anatomia & histologia , Dente Molar/diagnóstico por imagem , Adolescente , Adulto , Distribuição por Idade , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Brasil , Criança , Feminino , Humanos , Masculino , Maxila , Pessoa de Meia-Idade , Valores de Referência , Distribuição por Sexo , Fatores Sexuais , Adulto Jovem
18.
Niger J Clin Pract ; 22(7): 957-960, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31293261

RESUMO

Objectives: Hypercementosis (HC) is an asymptomatic excessive cementum deposition at the dental root apex. There is a lack of research that determines the pattern and associated factors of HC in Saudi Arabia. Materials and Methods: A retrospective cross-sectional study was conducted on a random sample of 815 Orthopantomograms (OPGs) that was obtained from a total of 14003 female patients archived OPGs. The OPGs were retrieved from the Kodak Carestream-R4 database for the period between 2015 and 2017 at Taibah University Dental College and Hospital (TUDCH), Al-Madinah Al-Munawwarah, Saudi Arabia. Width and radiodensity of HC were measured and the distribution was calculated. Association between HC and factors including age and nationality were explored. Descriptive and inferential analyses were performed. Results: The mean/SD age of HC affected patients (9.8%) was 30.16 ± 13.1 years, of whom 55% were Saudis. The mean/SD width and radiodensity of the hypercementosed roots were 4.14 ± 1.2 mm and 119.86 ± 29.83, respectively. The mandibular teeth were more frequently associated with hypercementosis (65%) specifically first molars (47.5%), while the majority (64%) had a single unilateral distribution pattern. There was a non-significant association between nationality, age, and HC (P = 0.921, P = 0.633, respectively). Conclusion: Hypercementosis observed in 9.8% of female patients attending TUDCH which was primarily unilateral and prominently confined to the mandibular teeth roots. The complication of teeth extraction among female patients in Almadinah region should be anticipated.


Assuntos
Hipercementose/diagnóstico por imagem , Mandíbula/diagnóstico por imagem , Dente Molar/diagnóstico por imagem , Radiografia Panorâmica/métodos , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Arábia Saudita , Adulto Jovem
19.
Forensic Sci Med Pathol ; 15(4): 570-573, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31327135

RESUMO

PURPOSE: The introduction of modern 3D image acquisition systems has enabled researchers to develop novel procedures for personal identification. The present study aimed to assess differences between dental scans belonging to the same or different subjects, through an innovative 3D-3D superimposition and registration method. METHODS: Twelve subjects (6 males and 6 females) with pre- and post-orthodontic treatment dental casts were recruited. A 3D scan from each cast was obtained through a laser scanner and the 3D model of the upper first and second molar on the post-treatment cast was superimposed on the pre-treatment scan, for a total of 12 matches and 100 mismatches. Point-to-point RMS (root mean square) distance was then calculated. Student's t test verified possible statistically significant differences according to group (matches/mismatches; p < 0.05). RESULTS: In case of matches, on average the point-to-point distance RMS was 0.29 mm (SD: 0.08 mm), while it was 0.94 mm (SD: 0.30 mm) for mismatches, with a statistically significant difference (p < 0.001). CONCLUSIONS: Results show that the novel procedure was able to distinguish matches from mismatches through an RMS threshold (0.50 mm): a possible method for personal identification is described, which needs to be verified through the application to a larger sample of casts.


Assuntos
Modelos Dentários , Imageamento Tridimensional , Dente Molar/diagnóstico por imagem , Adolescente , Feminino , Odontologia Legal/métodos , Humanos , Lasers , Masculino , Mandíbula , Maxila , Estatística como Assunto , Adulto Jovem
20.
Microsc Res Tech ; 82(10): 1748-1755, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31313438

RESUMO

The aim of the study was to compare different imaging methods in the diagnosis of microcracks on root dentin and to evaluate the frequency of dentinal microcracks observed after root canal preparation using the ProTaper Universal (PTU) system of different sizes. A total of 30 mandibular molars' mesial roots were scanned with microcomputed tomography (micro-CT) and cone beam computed tomography (CBCT) imaging methods before instrumentation. Root canal instrumentation was performed up to PTU F2 and F4 files. After instrumentation stages, the roots were scanned again with micro-CT and then with CBCT in same parameters. All roots were sectioned horizontally at 2, 4, 6, 8, and 10 mm from the apices of the specimens. The sections were imaged under a stereomicroscope. Finally, imaging of the sections was done by scanning electron microscopy (SEM). Statistical data analysis of instrumentation steps was performed using Friedman and Wilcoxon tests, and the data of imaging methods were analyzed using Kruskal-Wallis and Mann-Whitney U tests (p = .05). Instrumentation with the PTU system up to F2 and F4 files significantly increased the number of microcracks compared with preoperative samples according to micro-CT imaging (p < .05). For detecting microcracks on the root dentin, there were no statistically significant differences between micro-CT (43.9%) and stereomicroscopy (45.8%) (p < .05). SEM showed significantly higher percentage of microcracks (88.3%) (p > .05). No microcrack was observed using the CBCT method. There were no statistically differences between micro-CT and stereomicroscopy. SEM showed more dentinal microcracks while no microcrack was observed with CBCT.


Assuntos
Dentina/diagnóstico por imagem , Dentina/lesões , Diagnóstico por Imagem/métodos , Raiz Dentária/diagnóstico por imagem , Raiz Dentária/lesões , Humanos , Dente Molar/diagnóstico por imagem , Dente Molar/lesões , Preparo de Canal Radicular/efeitos adversos
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