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1.
Clin Oral Investig ; 25(1): 231-236, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32474809

RESUMO

OBJECTIVES: To evaluate ex vivo the efficacy of the integrated motor Tri Auto ZX2 in controlling the apical extent of preparation compared to conventional visual control (CVC) of the working length (WL). MATERIALS AND METHODS: Eighty standardized mandibular premolars were divided into five groups (n = 16). In the CVC group, instruments were used in continuous rotation (CR) and visual control performed by means of rubber stoppers. For each of the remaining groups, it was assigned a combination of a motion (CR or optimal torque reverse (OTR)), and an apical function (Auto Apical Reverse (AAR) or Optimum Apical Stop (OAS)). Root canals were prepared using the apical functions at 0.5 mark using an alginate model. Difference between the final WL and the actual length post-instrumentation was calculated. Data were analyzed statistically with the significance set at 5% (ANOVA, Tukey HSD). RESULTS: There was no difference in the mean WL among the groups, except between the CR combined to OAS compared to CVC (P > 0.05). Although CVC resulted in two cases beyond the foramen, no significant difference was found among the groups when comparing the distributions of measurements (P > 0.05). CONCLUSIONS: All combinations of motion and apical control functions of Tri Auto ZX2 provided an adequate apical limit ex vivo, similar to the visual control using rubber stoppers. CLINICAL RELEVANCE: TriAuto ZX2 was efficient to control the apical extent of preparation dispensing the need for calibrating the files, regardless of the different settings. This motor might potentially prevent over-instrumentation by continuously monitoring the apical limit.


Assuntos
Instrumentos Odontológicos , Preparo de Canal Radicular , Cavidade Pulpar , Eletrônica , Desenho de Equipamento , Odontometria , Ápice Dentário
2.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(6): 1130-1134, 2020 Dec 18.
Artigo em Chinês | MEDLINE | ID: mdl-33331326

RESUMO

OBJECTIVE: To analyze the esthetic proportions of maxillary anterior teeth in term of the apparent widths proportion of the adjacent teeth and width/height ratio of the clinical crown in 120 Chinese adults. METHODS: Maxillary gypsum casts were obtained from the dental laboratories of stomatological hospitals in North China, Southeast China, and Southwest China, according to the inclusion criteria and exclusion criteria. Standardized digital photographs of each cast were recorded. The apparent widths and actual widths and heights of the central incisors, lateral incisors and canines were determined by ImageJ software for the calculation of apparent widths proportion of the adjacent teeth and width/height ratio of the clinical crown. The ideal apparent widths proportion (Golden proportion and Preston proportion) and width/height ratio (0.80) were tested. The gender, arch side, and regional differences were investigated. RESULTS: The apparent widths proportion of the lateral/central incisor was 0.724±0.047, of the canine/lateral incisor was 0.814±0.092. The width/height ratio of the central incisor was 0.848±0.072, of the lateral incisor was 0.834±0.094, of the canine was 0.883±0.098. The esthetic proportions were different from the predicted ideal ratio (P < 0.001). The apparent widths proportion of lateral/central incisor was significantly larger in the right side than that in the left side (0.730± 0.044 vs. 0.718±0.050), and was significantly smaller in North China than that in Southwest China (0.711±0.051 vs. 0.731±0.044). The width/height ratio of the central incisor was significantly larger in the female than that in the male (0.855±0.074 vs. 0.835±0.068), and in the right side than that in the left side (0.855±0.073 vs. 0.842±0.072). The width/height ratio of the lateral incisor was significantly larger in the female than that in the male (0.843±0.097 vs. 0.817±0.084). CONCLUSION: The apparent widths proportion of adjacent teeth and the width/height ratio of the clinical crown in Chinese adults are different from the foreigner's. The esthetic proportion parameters have significant population specificity, and the measurements cannot be generalized as well as it should be applied with caution.


Assuntos
Dente Canino , Coroa do Dente , Adulto , Grupo com Ancestrais do Continente Asiático , China , Estética , Estética Dentária , Feminino , Humanos , Masculino , Maxila/anatomia & histologia , Odontometria , Coroa do Dente/anatomia & histologia
3.
Artigo em Inglês | MEDLINE | ID: mdl-33151201

RESUMO

From a sample of 108 periodontally healthy volunteers with different combinations of morphometric data related to maxillary central anterior teeth and the surrounding soft tissues, this article aims to categorize gingival phenotypes according to tooth and gingival parameters, as well as assess the relationships between tooth shape and gingival characteristics, such as the papillary height (PH) and faciolingual thickness (FLT) of the papilla base. The periodontal phenotypes of 108 volunteers were confirmed using the periodontal probe transmission method for Kan classification. The FLT, PH, and the crown width to crown length (CW/CL) ratio for maxillary anterior teeth were measured. K-clustering was used to classify the anterior tooth shape into three groups: triangular, square, and compound. The mean CW/CL ratio for the maxillary anterior tooth position of the thick phenotype was greater than that of the thin phenotype. The PH and FLT for the maxillary anterior interdental papillae were greater for the thin phenotype group than for the thick phenotype group. A negative correlation was observed between the CW/CL ratio and both PH and FLT (P < .05 for both). However, a significant positive correlation was observed between FLT and PH. CW/CL ratio, FLT, and PH were all associated with the gingival phenotype with significant statistical correlations (P < .05 for all). Triangular teeth were correlated with scallop-shaped gingiva in the faciolingual area, while square teeth were associated with a flat gingiva.


Assuntos
Dentição , Gengiva , Coroas , Humanos , Maxila/diagnóstico por imagem , Odontometria , Coroa do Dente/diagnóstico por imagem
4.
Braz Dent J ; 31(4): 404-408, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32901717

RESUMO

The aim of this study was to evaluate the influence of different coronal preflaring protocols (absent, conservative and conventional) on the accuracy of Root ZX II, Raypex 6, and RomiApex A-15 electronic foramen locators (EFLs). Twenty mandibular molars with Vertucci's type IV mesial roots were subjected to endodontic exploration and foraminal patency confirmation. Under 16x magnification, its real lengths (RL) were measured and registered (RL1). The canals were then irrigated with 2.5% sodium hypochlorite and electronically measured (EM1) employing the alginate model; all measurements were performed in triplicate by a blind operator using adjusted endodontic hand-files introduced until the apex foramen. Coronal preflaring procedures were sequentially performed with #25/.06 (conservative) and #25/.12 (conventional) instruments; new RLs extents were performed after each coronal preparation protocol (RL2/RL3), as same as electronic measurements (EM2/EM3). The devices error (mm) was evaluated considering the difference between RLs and EMs at each preparation stage; their precision was stablished adopting ±0.5 mm as tolerance margin. The EFLs error significantly reduced after conventional coronal preflaring protocol (p<0.05), which not occur after the conservative one. The best precisions values were noted after conventional preparation as 90% (Root ZX II), 97.5% (Raypex 6), and 92.5% (RomiApex A-15). No significant differences were found in EFLs comparisons, regardless of the coronal protocol tested (p>0.05). Under the conditions tested it can be concluded that the EFLs evaluated were precise. Moreover, the preflaring protocols influences its accuracy's, where the less conservative one produced the best results.


Assuntos
Preparo de Canal Radicular , Ápice Dentário , Cavidade Pulpar , Eletrônica , Odontometria
5.
J Indian Soc Pedod Prev Dent ; 38(2): 158-163, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32611862

RESUMO

Background: Accurate root canal length determination, simplicity of the procedure, and patient's cooperation are important determinants in the success of endodontic treatment in primary teeth. Aim: The aim of the study was to clinically compare the accuracy of Propex Pixi and Formatron D10 apex locators with conventional radiography in determining working length in mandibular primary second molars with and without varying degrees of physiological root resorption. Design: A nonrandomized clinical trial was conducted in 115 mandibular primary second molars indicated for pulpectomy in 90 pediatric dental patients. A single calibrated examiner determined the working length by conventional radiographic method and electronic apex locator (EAL) methods in a total of 376 canals. Behavior of the children during execution of each method in each tooth was recorded using the Frankl's behavior rating scale. The data obtained were tabulated and subjected to statistical analysis. Results: Significant correlation (intraclass correlation = 0.80 and 0.81, P < 0.001) could be detected between working length measurements obtained using Propex Pixi and Formatron D10 and measurements obtained using conventional radiography. Higher percentage of negative behaviors (negative and definitely negative) was observed during the conventional radiographic method (68.6%) as opposed to the Propex Pixi (16.5%) and Formatron D10 (20.8%) methods. Conclusions: Both the apex locators were as accurate as conventional radiography in determining working length in primary teeth; Formatron D10 being more accurate than Propex Pixi. The EALs were far better accepted by children than conventional radiography.


Assuntos
Cavidade Pulpar , Ápice Dentário , Criança , Humanos , Dente Molar , Odontometria , Radiografia , Preparo de Canal Radicular , Dente Decíduo
6.
Am J Orthod Dentofacial Orthop ; 158(3): 391-399, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32653347

RESUMO

INTRODUCTION: Enameloplasty of maxillary canines is often needed for aesthetic substitution in patients with congenitally missing lateral incisors. The exact enamel thicknesses for the various canine surfaces are unknown because previous studies failed to employ accurate measurement tools to report and compare detailed enamel thicknesses for each surface at various crown heights. METHODS: Thirty-two extracted maxillary canines were collected and scanned in a microcomputed tomography scanner. The scans were imported into a custom-written MATLAB software (version 9.2; MathWorks, Natick, Mass) and the enamel thickness on the mesial, distal, labial, fossa, cingulum, and incisal edge of each tooth was computed, obtaining the mean value from slices at 0.1 mm intervals. The overall mean enamel thickness for each surface was also calculated, and these values were compared using paired t tests. Incisal wear stage and incisal enamel thickness that was measured were compared using Spearman rank correlation coefficient. RESULTS: The mean enamel thickness was significantly thinner at the gingival level when compared with the incisal for all surfaces that were analyzed (1-tailed, P <0.001). The mean enamel coverage at the mesial was significantly thinner than the distal when measured gingival to the widest mesiodistal area. The mean enamel coverage of the cingulum was particularly thin and therefore requires extreme care in reshaping it. Incisal edge enamel thickness was highly negatively correlated with the wear stage of the scoring system that was used (1-tailed, P <0.001). CONCLUSIONS: The enamel coverage of the maxillary canine varies depending on the tooth surface and the incisogingival measurement location.


Assuntos
Dente Canino , Estética Dentária , Esmalte Dentário , Humanos , Maxila , Odontometria , Microtomografia por Raio-X
7.
Med. oral patol. oral cir. bucal (Internet) ; 25(3): e337-e345, mayo 2020. ilus, tab, graf
Artigo em Inglês | IBECS | ID: ibc-196319

RESUMO

BACKGROUND: This study evaluated the epidemiological and morphological features of the mandibular incisive canal (MIC) using cone beam computed tomography (CBCT) in a significant sample of subjects in Brazil. MATERIAL AND METHODS: This retrospective, multicenter study assessed 847 CBCT scans performed at four oral imaging centers. The sample comprised CBCT images acquired from dentate individuals who presented at least from tooth 35 to tooth 45 in the anterior mandible region. Data regarding patient sex and age, and MIC linear measurements (length and diameter in mm), anatomical distances (to the alveolar, buccal and lingual cortexes, inferior border of the mandible, and adjacent teeth apexes), and location were obtained. RESULTS: The MIC was more prevalent in women (76.3% [p < 0.001]) between the fourth and sixth decades of life (p < 0.001). It was present bilaterally (p < 0.001) and exhibited a mean length of 7.7 mm (standard deviation [SD]=3.7 mm). Spearman correlation and logistic regression analysis revealed collinearity between age and linear measurements (p < 0.05). The mean distances varied from the initial to the final portion of the MIC, respectively, in relation to the buccal cortex (mean = 2.6 mm, SD = 1.27; mean=3.96 mm; SD =1 .43), to lingual cortex (mean=5.13 mm; SD=1.7; mean = 4.61 mm, SD = 1.65), and to the inferior mandibular border (mean = 9.32 mm, SD = 1.92; mean=8.76 mm, SD = 2.07 mm). The difference in the proximity of the MIC to the apex of the inferior lateral incisor was statistically significant (p < 0.05). CONCLUSIONS: Results of this study revealed a high prevalence of MIC with a bilateral pattern in women who were between the fourth and sixth decades of life. Both the distance between the MIC and the lingual cortex of the mandibular alveolar bone, and the diameter of the MIC, decreased as its trajectory assumed a more anterior position


No disponible


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Mandíbula/diagnóstico por imagem , Tomografia Computadorizada de Feixe Cônico/métodos , Mandíbula/anatomia & histologia , Estudos Retrospectivos , Odontometria , Radiografia Panorâmica , Estatísticas não Paramétricas , Análise de Variância , Fatores Sexuais , Fatores Etários
8.
Niger J Clin Pract ; 23(5): 596-602, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32367864

RESUMO

Aim: The aim of this retrospective study is to evaluate and compare the 3-dimensional (3D) crown sizes of the left and right sides of upper and lower dental arches in patients with unilateral cleft lip and palate (UCLP). Materials and Methods: Dental casts of 94 patients all in permanent dentition were included in this study. Dental casts were divided into three groups as 36 casts with unilateral left cleft lip and palate (ULCLP), 18 casts with unilateral right cleft lip and palate (URCLP), and 40 casts without cleft (control). Mesiodistal (MD), buccolingual (BL), and gingiva incisal (GI) values of each tooth were measured by scanning the dental models with a high-precision optical 3D scanner. Paired t-test and independent t-test were used for statistical analysis. Results: U1 MD, U6 MD (P = 0.001) and BL (P = 0.01), L3 GI (P = 0.05) were greater in UCLP patients on the non-cleft side while U1 GI, L1 BL, L5 MD (P = 0.001), L4 MD, and BL (P = 0.01) values were found to be greater on the cleft side. Comparison of the cleft-sides and the control group showed that MD, BL, and GI dimensions of teeth on the cleft sides were generally found to be smaller, excluding the UR7 GI values for URCLP group (P = 0.05). Conclusion: In the measurements of teeth size, reliable and repeatable results were acquired through 3D software. Tooth size asymmetries can occur non-syndromic UCLP patients in both jaws. MD, BL, and GI dimensions of teeth are mostly found to be smaller in patients with CLP.


Assuntos
Fenda Labial , Imageamento Tridimensional/métodos , Odontometria/métodos , Coroa do Dente/diagnóstico por imagem , Estudos de Casos e Controles , Criança , Fissura Palatina/patologia , Oclusão Dentária , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Maxila , Estudos Retrospectivos , Coroa do Dente/patologia
10.
Int Endod J ; 53(7): 1007-1016, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32220071

RESUMO

AIM: To evaluate a modular 3D print training dental model with embedded human teeth and electronic working length determination for undergraduate endodontic education. METHODOLOGY: Cone-beam volume tomography data of a human skull were transferred into stereolithographic (STL) data, and a customizable modular 3D print model with individually removable sextants and teeth was generated for the use in commercially available phantom heads. Each of sixty-eight students performed a complete root canal treatment on an extracted human tooth. Working lengths were determined with electronic apex locators (EAL) and verified radiographically. Subsequently, an evaluation was carried out with regard to the difficulty of the working steps access cavity preparation, working length determination, root canal preparation/irrigation and canal filling, and these steps were compared to commonly used benchtop models. Additionally, the agreement of electronic and radiographic working length determination was assessed and analysed statistically with the chi-square test. RESULTS: A total of 68 teeth (20 incisors, 26 premolars and 22 molars) with 127 root canals were treated. In total, 87% of the students considered the modular 3D print model considerably more demanding than the conventional benchtop model. Overall, 96% felt better prepared for the clinical situation, 92% felt markedly reduced stress levels during endodontic practice in the subsequent clinical courses, and 93% of the students suggested the model should be used in future preclinical endodontic training. The preradiographic use of EAL resulted in 85% of the cases having radiographically acceptable working length determination within 0-2 mm from the radiographic apex. Readings more than 2 mm from the apex or beyond were significantly more common in molars than in premolars and incisors (P < 0.05). CONCLUSIONS: The vast majority of students rated the modular 3D print training model positively despite it being more demanding. They also recommended its use in preclinical teaching and training. The model allowed a more realistic simulation of the clinical situation with a simultaneous use of EALs and led to reduced stress levels in endodontic treatment in the subsequent clinical courses.


Assuntos
Cavidade Pulpar , Preparo de Canal Radicular , Humanos , Dente Molar , Odontometria , Tratamento do Canal Radicular , Ápice Dentário
11.
Br Dent J ; 228(6): 449-455, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32221449

RESUMO

Introduction Many aesthetic proportions have been proposed for use in dentistry: Golden Proportion, Preston's Proportion, Recurrent Esthetic Dental (RED) Proportion and Golden Percentage. Although there have been studies to consider these proportions in other countries, there have been no studies in the UK to evaluate their prevalence and value.Methods The maxillary anterior teeth of 509 students from University of Birmingham's School of Dentistry were photographed in a standardised manner and the aesthetic proportions statistically analysed using an unpaired one-sample t-test.Results Golden Proportion existed in a very limited number of the sample. RED did not exist in the sample. The sample's average ratio was similar to Preston's Proportion; however, there was too wide a distribution for the proportion to be of relevant use. The vast majority of the sample conformed to modified Golden Percentage values; 22.5% for central incisors, 15% for lateral incisors and 12.5% for canines.Conclusion Golden Proportion, Preston's Proportion and RED Proportion have limited value in aesthetic dentistry as they do not accurately or broadly represent natural, aesthetic smiles. However, slightly modified Golden Percentage values are vastly more representative and are recommended as a more relevant geometric component to smile design principles in the UK.


Assuntos
Estética Dentária , Maxila , Humanos , Incisivo , Odontometria , Reino Unido
12.
BMC Oral Health ; 20(1): 87, 2020 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-32213166

RESUMO

BACKGROUND: Careful consideration and assessment of the type of phenotype has gained a fundamental importance in the treatment planning for any patient. We evaluated the prevalence of gingival phenotypes in a sample of Yemeni population and to explore its relationships to gender, age and other risk factors. METHODS: This cross-sectional study was performed among 456 patients. All maxillary anterior teeth were included for all parameters and 1st molars were included for gingival thickness measurements. All patients included in this study were systemically healthy and presented no dental crowding. Four clinical parameters were systematically recorded: Gingival thickness (GT), Width of keratinized gingiva (WKG), Crown width/ crown length (CW/CL) ratio and Papilla height (PH). Scores obtained from different parameters measurements were recorded and analyzed using non-parametric tests where P-value < 0.05 was considered significant. One examiner performed all measurements. RESULTS: The mean age was 29.9 ± 8.26 years. Of 456 recruited subjects, 83 (18.2%) subjects had thin, 69 (15.1%) had thick GT and 304 (66.7%) were placed in non-categorized (1.5-2 mm) GT. Square crown shape was found in 210 (44.1%) patients and 245 patients (55.9%) showed rectangular shape. Regarding WKG, 114 (25%) patients had width < 4 mm, 319 (70%) had width 4.1-8 mm and 23 (5%) patients had width >  8 mm. There was no significant difference between males and females for GT measurements. Regarding WKG, results showed that the prevalence of WKG 4.1-8 mm was more among females while males had more prevalence of ≤4 mm with significance difference. PH showed no significant differences between males and females. Regarding age, there was no significant differences between patients ≤25 years and >  25 years for all gingival parameters measurements. The relationship of smoking with different gingival parameters also showed no significant differences between smokers and non-smokers. Similarly, relationship of khat chewing with different gingival parameters showed no significant difference. Regarding inter-relationship between parameters, thin GT was associated with rectangular tooth form while square and quadrate forms are more associated with "1.5-2 mm" GT. WKG of ≤4 mm was associated with rectangular tooth form while WKG >  8 was more associated with square and quadrate forms with no significant difference. Results showed significant association between thin GT with 4.1-8 mm WKG. CONCLUSION: Yemeni population had more prevalence of "1.5-2 mm" GT, rectangular crown shape and WKG from 4.1-8 mm. Regarding interrelationship between gingival parameters, GT showed obvious relationship with WKG, CW/CL ratio and PH. WKG with CW/CL also showed significant relationship while no relationship was shown between other gingival phenotype parameters.


Assuntos
Gengiva/anatomia & histologia , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Odontometria , Fenótipo , Fatores de Risco , Iêmen , Adulto Jovem
13.
J Appl Oral Sci ; 28: e20190103, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32049131

RESUMO

OBJECTIVE: This study aimed to assess the association between tooth size and root canal morphology by using CBCT analysis. METHODOLOGY: In this retrospective study, tooth anatomic lengths (crown and root lengths, buccolingual and mesiodistal dimensions) of 384 patients were assessed and correlated with Vertucci's root canal morphology classification. Data was analyzed for gender-related differences using the independent sample t-test, ANOVA, and the Pearson's correlation for a possible relation between anatomic lengths and canal morphology. RESULTS: The maxillary first and second premolars showed a greater predilection for Type IV and II variants, respectively, while the mandibular first premolar showed a greater predilection for Type II canal system. The root canal system of the mandibular second premolar showed maximal diversity (47% Type I, 30% Type II, and 20% Type III). The dimensions were greater in men regardless of tooth type. The most significant relation (p<0.05) between the anatomic size and canal morphology was observed in the maxillary first premolars, followed by the mandibular canines (buccolingual dimension) and the lower second premolars (crown length). Negative correlations existed between the crown length and the patient's age for the anterior teeth and mandibular second premolar (r=-0.2, p<0.01). CONCLUSIONS: The most common canal formation for anterior teeth was the Type I. The anatomic lengths had the strongest influence on the canal configuration of the maxillary first premolar, with Type IV being the most common root canal system. The mandibular second premolars showed maximal diversity in the canal classification terms and had a significant correlation with their crown lengths. CLINICAL RELEVANCE: The complex relationship between the canal morphology and anatomic tooth sizes need meticulous awareness and recognition during endodontic procedures, in conjunction with the demographic variabilities.


Assuntos
Tomografia Computadorizada de Feixe Cônico/métodos , Cavidade Pulpar/anatomia & histologia , Dente/anatomia & histologia , Adulto , Idoso , Análise de Variância , Cavidade Pulpar/diagnóstico por imagem , Feminino , Humanos , Masculino , Mandíbula/anatomia & histologia , Mandíbula/diagnóstico por imagem , Maxila/anatomia & histologia , Maxila/diagnóstico por imagem , Pessoa de Meia-Idade , Odontometria/métodos , Valores de Referência , Estudos Retrospectivos , Fatores Sexuais , Dente/diagnóstico por imagem , Estados Unidos
14.
J Appl Oral Sci ; 28: e20190148, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32049133

RESUMO

OBJECTIVE: The site of the sinus tract depends on the rate of resistance against abscess exudate drainage, bone morphology, and distance from the root apex to the outer cortical bone. To assess apical bone thickness in buccal and palatal/lingual aspects of maxillary and mandibular teeth, using a high-resolution cone-beam computed tomography (CBCT) system. METHODOLOGY: In total, 422 CBCT examinations were included in the study, resulting in a sample of 1400 teeth. The scans were acquired by PreXion 3D, with a high-resolution protocol. The bone thickness was taken as the distance between the center of the apical foramen and the buccal and lingual/palatal cortical bone. The quantitative variables were expressed as mean values±standard deviation. The independent samples were analyzed using the t-test or the Mann-Whitney test (p<0.05). RESULTS: The lowest mean value of bone thickness was observed in the buccal cortical bone of the upper canines (1.49 mm±0.86) and in the upper central incisors (1.59 mm±0.67). In premolar teeth, the lowest values were found in the buccal cortical bone of upper first premolars (1.13 mm±0.68). In the posterior teeth, the lowest values were found in the buccal cortical bone of upper first molars (1.98 mm±1.33). In the lower second molar region, the buccal cortical bone (8.36 mm±1.84) was thicker than the lingual cortical bone (2.95 mm±1.16) (p<0.05). CONCLUSIONS: The lowest mean values of bone thickness are in the buccal cortical bone of the maxillary teeth. In the mandible, bone thickness is thinner in the buccal bone around the anterior and premolar teeth, and in the lingual aspect of mandibular molars. All these anatomic characteristics could make the occurrence of the sinus tract more susceptible in these specific regions of the maxillary and mandibular alveolar bone.


Assuntos
Tomografia Computadorizada de Feixe Cônico/métodos , Mandíbula/anatomia & histologia , Maxila/anatomia & histologia , Dente/anatomia & histologia , Adulto , Feminino , Humanos , Masculino , Mandíbula/diagnóstico por imagem , Maxila/diagnóstico por imagem , Odontometria/métodos , Valores de Referência , Estatísticas não Paramétricas , Dente/diagnóstico por imagem
15.
Am J Orthod Dentofacial Orthop ; 157(2): 218-227, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32005474

RESUMO

INTRODUCTION: The aim of this study was to investigate the vestibular anatomy of teeth in samples of adult Italian and Mozambican subjects in ideal occlusion and permanent dentition and identify any anatomic characteristics that may influence bonding in the straight-wire technique. METHODS: Linear measurements and coordinates of each curve representing the clinical crown height and width of each tooth were acquired from digital models of each subject categorized to 1 of 2 groups: Italian (18 males, 22 females; mean age, 29.6 ± 5.7 years) or Mozambican (14 males, 15 females; mean age, 23.4 ± 5.9 years). All subjects had normal dentition and no previous orthodontic treatment, fillings, or prostheses. Method error and systematic error were calculated according to the Dahlberg formula (S2 = ∑ d2/2n) and dependent Student t test (P <0.05), respectively. Tooth symmetry was investigated through a paired-samples t test (P <0.05) and sex difference via an independent-samples t test (P <0.05). After neither asymmetry nor sexual dimorphism was found, all data were pooled, inverting the signs of the X coordinates and then mirroring data. Subsequently, a 2-samples t test (P <0.05) and a multivariate cluster analysis were performed on the mirrored data to compare the 2 groups and to identify any within-group diversity for number of clusters for each tooth. Means of all linear measurements and coordinates (crown height and width) calculated for each cluster were reported and compared using a standard 2-samples t test (P <0.05). RESULTS: Two clusters were identified for the maxillary second premolars and molars in Italian subjects, whereas in the Mozambican subjects, there were 2 clusters for the maxillary first premolars and lateral incisors and 3 clusters for the maxillary canines and central incisors. The mandibular arch was remarkably homogeneous, with only 1 cluster per tooth in each group. In the mandibular arch, statistical differences were recorded between ethnic groups in crown height at the central incisors and second molars and in crown width in the sector from the second premolar to the second molar. CONCLUSIONS: There were considerable differences both between and within racial groups in crown height, crown width, and numbers of clusters, which should be taken into account during bonding. Although single-bracket placement guides specific for ethnicity may be feasible for the mandibular arch, the significant diversity in number of clusters in the maxillary arch indicates that more accurate bracket placement guides that take into account such heterogeneity are required.


Assuntos
Odontometria , Dente , Adolescente , Adulto , Dente Pré-Molar , Dente Canino , Feminino , Humanos , Itália , Masculino , Dente/anatomia & histologia , Coroa do Dente , Adulto Jovem
16.
J Nepal Health Res Counc ; 17(4): 501-505, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-32001856

RESUMO

BACKGROUND: Canines are known for their higher resistance to trauma and pathological alterations when compared to other teeth. Among all the teeth, canines show highest sexual dimorphism. METHODS: This descriptive cross-sectional study was commenced from January 2019 to April 2019 after the ethical approval from Institutional Review Committee. The maximum mesio-distal widths of right and left mandibular canines and mandibular inter-canine arch width were measured on the cast with the help of a divider and digital vernier callipers. Mandibular canine index was calculated by dividing the mesio-distal width of each mandibular canine with inter-canine arch width. Data was entered and analyzed using Statistical Package for the Social Sciences version 21. RESULTS: Sex predictability by using mandibular canine index in the present study showed poor sex predictability (57.5% - 62.5%). CONCLUSIONS: Sex determination should be done by other methods and mandibular canine index should be used cautiously in Nepalese population.


Assuntos
Dente Canino/anatomia & histologia , Odontologia Legal/métodos , Odontometria/métodos , Caracteres Sexuais , Estudos Transversais , Feminino , Humanos , Masculino , Nepal , Reprodutibilidade dos Testes
17.
J Endod ; 46(4): 509-514, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32089336

RESUMO

INTRODUCTION: This study aimed to investigate the importance of apical patency and its influence on the accuracy of 2 apex locators (Root ZX and Raypex 6). METHODS: We determined the actual working length under dental operating microscope at ×25 magnification in 43 extracted human mandibular molars with completely formed roots and patent apical foramen. Readings of the 2 apex locators were then compared with the actual microscopic working length. Thereafter, we established apical blockage at the apical foramen; files were introduced to the same previous length determined by each apex locator before blockage. Variation in the readings of apex locators after blockage was compared with original readings before blockage to determine the measurement error. RESULTS: Friedman's test showed no statistically significant difference between the 2 apex locators before blockage (P > .05; effect size = 0.013). Within the margin of accuracy ±1, both Root ZX and Raypex 6 revealed the same percentage of accuracy, 96.7%. After blockage, both apex locators revealed a statistically significant difference in median measurement error compared with the measurements before blockage (P < .05; effect size = 0.305). Root ZX showed a higher median measurement error (>-1 mm and 0.01-0.5 mm) than Raypex 6. CONCLUSIONS: Apical foramen blockage has a negative influence on the accuracy of apex locators that was more pronounced in Root ZX than Raypex 6.


Assuntos
Cavidade Pulpar , Ápice Dentário , Eletrônica Médica , Humanos , Dente Molar , Odontometria , Preparo de Canal Radicular
18.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(1): 124-128, 2020 Feb 18.
Artigo em Chinês | MEDLINE | ID: mdl-32071475

RESUMO

OBJECTIVE: To analyze the relationship between the width of the maxillary anterior teeth and the anterior arch perimeter, to analyze the change rule of the width of the anterior teeth and the anterior arch perimeter, when altered the convexity of the anterior arch, with the width of the maxillary anterior arch keeping constant, and to provide a reliable basis for later digitized and personalized aesthetic analysis of front teeth. METHODS: In the study, 61 front teeth complete and well-arranged models had been selected from the working models after the prostheses in Department of Prosthodontics, Peking University School and Hospital of Stomatology, including 22 male models and 39 female models. A photograph was taken from the occlusal surface of each model using the fixed magnification with a single lens reflex camera. The width of anterior teeth, the width of anterior arch and the convexity of anterior arch had been measured using the Photoshop software. The ratio of the width of the anterior teeth to the width of the anterior arch was calculated. Keeping the width of anterior arch unchanged, the layer free transformation function used to add or decrease the curvature of the anterior arch from 1-5 mm, each circumference of the anterior arch was measured. According to the proportion of their anterior teeth in the anterior arch perimeter, the width of each anterior teeth crown under different convexities of anterior arch was calculated. SPSS 23.0 was used to analyze the ratio of the width anterior teeth to the anterior arch perimeter and correlation between the convexity of the anterior arch and the width of the anterior teeth. RESULTS: The percentages of the median length of the anterior arch in the central incisor, lateral incisor and canine were 36.2%±1.3%, 30.2%±1.5%, and 33.6%±1.4%, respectively. The proportions were normal distributions and not related to the perimeter of the anterior arch. When the width of the anterior arch was constant, there was a positive correlation between the convexity of anterior arch in the range of 5 mm and the width of anterior teeth or the front arch circumference. With each increase or decrease of 1 mm of the convexity of anterior arch, the width of the middle incisor increased or decreased by about 0.18 mm, the half circumference of the anterior arch increased or decreased by about 0.50 mm. CONCLUSION: The width of the anterior teeth in the middle-distal direction remained stable in the anterior arch circumference. Within a certain range, when the width of the maxillary anterior arch remains unchanged, the width of the anterior teeth and the perimeter of the anterior teeth are positively correlated to the convexity of the anterior arch.


Assuntos
Dente Canino , Incisivo , Arco Dental , Feminino , Humanos , Masculino , Maxila , Odontometria , Software
19.
Am J Orthod Dentofacial Orthop ; 157(1): 80-90, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31901286

RESUMO

INTRODUCTION: Incisor root resorption associated with palatally displaced canine (PDC-IRR) is an important phenomenon that might alter the orthodontic treatment plan. The aims of this study were to investigate the prevalence and characteristics of PDC-IRRs, to compare PDC-IRR and PDC-No-IRR groups, to identify predictors for PDC-IRR, and to produce a valid PDC-IRR prediction model using discriminant function analysis. METHODS: Cone-beam computed tomography images for 107 palatally displaced canines (PDCs) and 51 fully erupted nondisplaced canines (NDC) were analyzed for the presence of incisor root resorption (IRR). The PDCs were divided into 2 groups: PDC-IRR (52 canines) and PDC-No-IRR (55 canines). The 3 groups were compared, and the following variables were measured: canine follicle size, contact with adjacent incisors, associated dental abnormalities, sector analysis, canine vertical relation to adjacent root, lateral incisor angulation and inclination, canine angulation and distance to reference planes (dental midline, midpalatal suture, occlusal plane, pterygoid vertical plane, and lateral incisor), and space available for canine in the dental arch. Discriminant functional analysis was used to produce a discriminant function equation to predict PDC-IRR. RESULTS: Root resorption affected 74% of lateral incisors adjacent to PDCs and 25.5% of lateral incisors adjacent to NDCs. IRR was located lingually in 41% of PDCs and in the mid and apical thirds in 89%. In the PDC-IRR group, 94.2% of canines were in contact with adjacent roots compared with 23.6% in the PDC-No-IRR group (P <0.001). Canine follicle size was >2 mm in 42% of PDC subjects. Overall mean value of follicle width in PDC canines was 1.79 ± 1.06 mm. Peg-shaped lateral incisors were recorded in 19% of PDC subjects compared with 4% in NDCs (P = 0.012). The stepwise analysis using cone-beam computed tomography records produced a discriminant function based on 3 variables. The analysis correctly predicted the outcome in 83% of subjects. The variables contributing to the prediction equation were canine contact with adjacent incisors, size of canine dental follicle, and the presence of peg-shaped lateral incisor. CONCLUSIONS: Canines in contact with adjacent incisor roots was the only risk factor detected for PDC-IRR. Very good predictive discrimination (83%) emerged for PDC-IRR subjects. Predictors of PDC-IRR were canine contact with adjacent incisor, size of canine dental follicle, and presence of peg-shaped lateral incisor.


Assuntos
Reabsorção da Raiz , Dente Impactado , Dente Canino , Humanos , Incisivo , Odontometria
20.
Homo ; 71(1): 19-28, 2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-31939990

RESUMO

Background: Sex determination is the first step in personal identification in the forensic field. This study aimed to evaluate sexual dimorphism by using palatal rugae pattern and odontometrics, construct an Egyptian equation for sex determination using the discriminant function analysis. Participants and methods: The study sample included 200 participants of both sexes. Maxillary arch impressions were taken with alginate impression material using stainless steel impression tray. Identification and measurements were done to study the palatal rugae pattern, dental arch dimensions, and maxillary canine. Results: There was a highly statistically significant difference between males and females with higher male values regarding the total palatal rugae number, wavy rugae number, primary rugae number, arch length, width, maxillary canine right width, maxillary canine left width, intercanine distance, and maxillary canine right index while there was a highly statistically significant difference with higher female value regarding the straight rugae numbers. Four Egyptian equations were constructed using discriminant function analysis to determine the sex of an unidentified person. Conclusions: Palatal rugae pattern, dental arch dimensions, and maxillary canine index can be considered as useful tools for sex determination in the forensic field.


Assuntos
Odontometria/métodos , Análise para Determinação do Sexo/métodos , Adulto , Dente Canino/anatomia & histologia , Arco Dental/anatomia & histologia , Análise Discriminante , Egito , Feminino , Humanos , Masculino , Palato/anatomia & histologia , Projetos Piloto , Adulto Jovem
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