Design of surgical procedures for patients with special protrusion with digital technology / 中华医学美学美容杂志

Objective:To analyze the symmetry of different reference planes in the surgical simulation design of patients with protrusive jaw deformity with high and low eyes.Methods:Fifteen patients with partial jaw deformity were selected from January 2019 to June 2020, including 3 males and 12 females, aged 18-26 years, with average 23.78 years. Inclusion criteria were that the patients, aged more than 18 years, were diagnosed as protrusive jaw deformity with maxillary occlusal plane tilt and high and low eyes by clinical and imaging analysis. Three different 3D reference plane systems were established by different modeling methods. The distance between the landmarks of soft and hard tissues and the median sagittal plane was measured. The symmetry of skull was qualitatively analyzed by mirror image technique. The difference of three reference planes in surgical simulation symmetry of patients with protrusion jaw and high and low eyes was evaluated by one-way ANOVA.Results:Qualitative analysis showed that in the three measurement planes, the symmetry of the third reference plane was the best, and the symmetry of the second and the first was poor. Quantitative analysis showed that in measurement index of hard tissue, there was statistical difference between the distance of each landmark in the reference plane established by Method 3 and Method 1, Method 2 [(1.65±1.19) mm; (3.37±1.58) mm; (3.26±2.36) mm, P<0.05], but there was no statistical difference between Method 1 and Method 2 (P > 0.05). The measurement result of soft tissue was consistent with that of hard tissue, and the distance of each landmark in Method 3 from the median sagittal plane was very small, and the mean error was less than 0.5 mm, which was consistent with the clinical results. Conclusions:Digital model surgery technology can assist orthognathic surgeons in the design and prediction of surgical scheme, especially for patients with special partial jaw deformity.

Linear dimensional change of edentulous models made of high-density laboratory silicones at different storage times / Alteração dimensional linear de modelos edêntulos fabricados com silicones laboratoriais de alta densidade em diferentes tempos de armazenagem

ABSTRACT Objective: To evaluate the dimensional change of edentulous models made of high density laboratory silicones at different storagetimes. Methods: A metallic master model simulating an edentulous maxilla was used. The model had projections of 1.8 cm located in the regions of canines (A and B) and molars (C and D) allowing the linear measurement of distances AB, BC, CD, DA, AC and BD. A laboratory silicone mold was made for duplication of master model in the following materials (n = 10): G1: Zetalabor 85, G2: Titanium 95, G3: Platinum 95 and G4: Gypsum type III (control). The samples were photographed and measured using a software (Image J) at times T1 (baseline) and T2 (after one week of models fabrication). The data were statistically analyzed using Kruskal- Wallis and Dun non-parametric tests (α = 0.05). Results: The storage time influenced the behavior of the materials evaluated. All groups presented dimensional changes in both times and the group Tit95 presented the best results. Only Zet85 group showed a different behavior related to the region of the model. Conclusions: The high density laboratory silicones showed satisfactory results when compared to the gypsum group. Tit95 was the most stable material and it can be recommended as an edentulous model for total protheses.

RESUMO Objetivo: Avaliar a alteração dimensional de modelos edêntulos fabricados em silicone laboratorial de alta densidade em diferentes tempos de armazenagem. Métodos: Um modelo mestre metálico simulando uma maxila edêntula foi utilizado. O modelo possuía projeções oclusais de 1,8 cm localizadas nas regiões de caninos (A e B) e molares (C e D), permitindo a mensuração das distâncias lineares AB, BC, CD, DA, AC e BD. Um molde foi fabricado em silicone laboratorial para duplicação do modelo mestre com os seguintes materiais (n = 10): G1: Zetalabor 85, G2: Titanium 95, G3: Platinum 95 e G4: Gesso tipo III (controle). As amostras foram fotografadas e mensuradas com auxílio de um software (Image J) nos tempos T1 (baseline) e T2 (após uma semana de confecção). Os dados obtidos foram avaliados estatisticamente utilizando os testes não paramétricos de Kruskal- Wallis e Dunn (α = 0.05). Resultados: O tempo de armazenagem influenciou o comportamento dos materiais avaliados. Todos os grupos apresentaram alterações dimensionais em ambos os temos de avaliação e o G2 apresentou os melhores resultados. Apenas o grupo G1 mostrou alteração dimensional dependente da região mensurada. Conclusão: Silicones laboratoriais de alta densidade mostraram resultados satisfatórias de alteração dimensional quando comparados ao gesso tipo III. O material Titanium 95foi o mais estável e pode ser recomendado como alternativa para a confecção de modelos edêntulos.

Association between posterior tibial slope and tibial torsion angle and recurrent patellar dislocation based on the full-length CT of the lower limbs / 解剖学报

Objective To measure and compare the lateral posterior tibial slope (LPTS) , medial posterior tibial slope ( MPTS) and tibial torsion angle ( TTA) between the patients of recuiTent patellar dislocation and the heathy people, and to analyze the correlation between LPTS, MPTS and TTA and the risk factors of recuiTent patellar dislocation. Methods A total of 33 patients (44 knees) with recuiTent patellar dislocation in our hospital from July 2019 to June 2021 were selected and listed as the stud)' group. Twenty-three subjects (46 knees) who were suspected iliac vascular and lower limb vascular diseases during the same period were selected and listed as the control group. All the enrolled researchers had fulllength CT scans date of the lower limbs. Three-dimensional models were reconstructed using Mimics 21. 0 software and then imported into 3-matic software. The LPTS, MPTS and TTA were measured and compared between the two groups. Results In the study group, the LPTS, MPTS and TTA were (7. 69} 1. 42) ° , ( 10. 06} 1. 71) ° , ( 36. 42}8. 13 ) ° , respectively while the control group, the LPTS, MPTS and TTA were ( 8. 42 } 1. 65 ) ° , ( 10. 44 } 0. 86 ) ° , ( 25. 77} 3. 90 ) ° , respectively. There were no signiiicant differences in the LPTS, MPTS and TTA between different genders and sides both in the stud)' group and the control group ( P > 0. 0 5 ) . Compared with the control group, the LPTS in the stud)' group was smaller, and the difference was statistically significant (P0. 05). Compared with the control group, the TTA in the stud)' group was higher, and the difference was statistically significant (P< 0. 0 5 ) . Compared with the control group, the LPTS and MPTS in the study group were significant asymmetry, and the difference was statistically significant ( P < 0 . 0 5 ). Conclusion The lateral posterior tibial slope of patients with recurrent patellar dislocation is significantly smaller than that in the healthy people, while there is no significant difference in the medial posterior tibial slope; The tibial torsion angle of patients with recurrent patellar dislocation is significantly larger than in the healthy people; The lateral posterior tibial slope and tibial torsion angle have certain correlation with recurrent patellar dislocation, which can conduct the diagnosis of recurrent patellar dislocation.

Big Five Inventory-2-Short: Evidências de Validade e Confiabilidade na Segurança Pública / Big Five Inventory-2-Short: Evidence of Validity and Reliability in Public Safety

O presente estudo teve como objetivo reunir evidências de validade de construto, baseadas na estrutura interna, do Big Five Inventory-2-Short (BFI-2-S) para o contexto da segurança pública brasileira. Participaram do estudo 9.742 agentes da segurança pública de diferentes corporações de todas as unidades federativas do Brasil. A maioria dos participantes era do sexo masculino 80,1% (ƒ = 8.156), com idades entre 18 e 73 anos (M = 41,55; DP = 8,02) e com tempo de trabalho na corporação entre 1 e 45 anos (M = 14,51; DP = 8,46). Os agentes responderam ao teste de personalidade BFI-2-S e a um questionário sociodemográfico, por meio de questionário eletrônico. A amostra foi dividida aleatoriamente em duas subamostras para validação cruzada. Em ambas as subamostras foram realizadas análises fatoriais exploratórias que indicaram uma estrutura trifatorial da BFI-2-S, com índices de fidedignidade adequados. Foram identificados os fatores extroversão, neuroticismo e conscienciosidade. Os itens referentes aos fatores amabilidade e abertura à experiência não apresentaram cargas fatoriais satisfatórias. Apesar da estrutura fatorial ter sido divergente do modelo teoricamente proposto pelo instrumento, isto é, o modelo de cinco fatores, o BFI-2-S se mostrou como um instrumento adequado para a avaliação das dimensões de conscienciosidade, neuroticismo e extroversão em servidores da segurança pública brasileiros.(AU)

The present study aimed to gather evidence of construct validity, based on the internal structure, of the Big Five Inventory-2-Short (BFI-2-S) for the context of Brazilian public security. 10.885 public security agents from different police forces from all federal units in Brazil were recruited through an electronic questionnaire, most were male, 80.1% (ƒ = 8,156), aged between 18 and 73 years (M = 41.55; SD = 8.02), working in the organization between 1 and 45 years (M = 14.51; SD = 8.46). Agents completed the BFI-2-S personality test and a sociodemographic questionnaire. The responses obtained were split into two random subsamples and a cross-validation procedure was performed. Thus, in both subsamples Exploratory Factor Analysis was carried out, which indicated a structure composed of three factors, with adequate reliability. Despite differing from the model theoretically proposed by the instrument, the BFI-2-S proved to be an adequate instrument for assessing the dimensions of conscientiousness, emotional instability and extroversion in Brazilian police officers.(AU)

El presente estudio tuvo como objetivo recopilar evidencias de validez de constructo, con base en la estructura interna, del Big Five Inventory-2-Short (BFI-2-S) para el contexto de la seguridad pública brasileña. 10.885 agentes de seguridad pública de diferentes corporaciones de todas las unidades federales de Brasil, la mayoría eran hombres 80,1% (ƒ = 8.156), con edad entre 18 y 73 años (M = 41,55; SD = 8,02) y con tiempo de trabajo en la corporación entre 1 y 45 años (M = 14.51; SD = 8.46). Los agentes completaron el test de personalidad BFI-2-S y un cuestionario sociodemográfico a través de un cuestionario electrónico. Las respuestas obtenidas se dividieron en dos submuestras aleatorias y se realizó un procedimiento de validación cruzada. Así, en ambas submuestras se realizaron Análisis Factoriales Exploratorios, los cuales indicaron una estructura compuesta por tres factores, con índices de confiabilidad adecuados. A pesar de diferir del modelo propuesto teóricamente por el instrumento, el BFI-2-S demostró ser un instrumento adecuado para evaluar las dimensiones de escrupulosidad, inestabilidad y extroversión en policías brasileños.(AU)

Establishment of a three-dimensional coordinate system for measuring the recurrence rate after orthognathic surgery and evaluation and analysis of the degree of recurrence / 口腔疾病防治

Objective@# To establish a three-dimensional coordinate system that can accurately measure the recurrence rate after orthognathic surgery, and evaluate and analyze the degree of recurrence.@*Methods @#Data from patients who underwent orthognathic surgery in a hospital were selected to reconstruct three-dimensional images with spiral CT. The two researchers used the multiplane assisted positioning method to fix the points three times and screened them using intra-andintreclass correlation coefficients (ICC). Reproducible and accurate landmark points were drawn to establish different coordinate systems and calculate the facial asymmetry index (AI) to determine the coordinate system with the best mid-sagittal plane symmetry. This coordinate system and lateral radiographs were used to separately measure the recurrence rate, and evaluate and analyze the three-dimensional recurrence degree of orthognathic surgery.@*Results @#Ten landmark points that may be repeatedly fixed were obtained, including N (nasion), K (K point), ANS(anterior nasal spine), PNS (posterior nasal spine), Ptm(pterygomaxillary fissure), Gn (gnathion), IZ(IZ point), MZ (MZ point), Ms (mastoideale), Cor (coronion) and and Go (gonion). Three coordinate systems were established, and the most suitable coordinate system was the upper edge point of the left infraorbital foramen. The inner upper edge of the right infraorbital foramen and both sides of the midpoint of the ear points constituted the horizontal plane (HP), which passed through the outermost point of the left zygomatic frontal suture and the outermost point of the right zygomatic frontal suture and was perpendicular to the horizontal plane to constitute the coronal plane (CP). It was perpendicular to the two planes to form a sagittal plane (SP). Two-dimensional and three-dimensional measurements of recurrence were performed on 112 patients, and new three-dimensional recurrence evaluation results were obtained. Less than 40% had low recurrence, 40% to 61% had moderate recurrence, and greater than 61% had high recurrence.@*Conclusion@#This study established a three-dimensional coordinate system suitable for measuring the recurrence rate after orthognathic surgery, obtained a new three-dimensional recurrence evaluation result, and provided a clinical experimental basis for evaluating the effect of orthognathic surgery and improving stability.

Agreement among instruments of quantitative evaluation of the hard palate in children / Concordância entre instrumentos de avaliação quantitativa do palato duro em crianças

ABSTRACT Purpose To evaluate the agreement among instruments of the quantitative evaluation of hard palate. Methods This cross-sectional study was performed with a sample of 30 children aged 6 to 11 from Santa Maria, Southern Brazil. The instruments for palate measurements evaluated were: digital caliper, used directly in the oral cavity and in plaster casts, Korkhaus tridimensional bow, used directly in the oral cavity and in plaster casts, and Dolphin Imaging Software used for measurements in cone-beam computed tomography (CBCT). The agreement among different instruments was evaluated using the Intraclass Correlation Coefficient (ICC). Results The means of all transversal dimensions obtained by cone-beam computed tomography were lower than those of the other instruments - the agreement values in the width between the canines and in the width between the first molars were lower when comparing the cone-beam computed tomography and the other instruments. In the width between the first and second premolars, all comparisons showed acceptable agreement values. Good concordance values were obtained when comparing the palate depth at the second premolar region when using a bow divider inside the oral cavity and in the cast. Conclusion Most instruments presented satisfactory agreement in the measurements related to the transverse plane of the hard palate. However, when the vertical plane was evaluated, only the bow divider applied to both cast and oral cavity presented ideal agreement.

RESUMO Objetivo Avaliar a concordância entre instrumentos de avaliação quantitativa do palato duro. Método Este estudo transversal foi realizado com uma amostra de 30 crianças de 6 a 11 anos de Santa Maria, sul do Brasil. Os instrumentos de medidas do palato avaliados foram: paquímetro digital, utilizado diretamente na cavidade oral e em modelos de gesso, arco tridimensional Korkhaus, usado diretamente na cavidade oral e em modelos de gesso, e Dolphin Imaging Software utilizado para medições em tomografia computadorizada de feixe cônico (CBCT). A concordância entre os diferentes instrumentos foi avaliada por meio do Coeficiente de Correlação Intraclasse (ICC). Resultados As médias de todas as dimensões transversais obtidas pela tomografia computadorizada de feixe cônico foram menores do que as dos outros instrumentos - os valores de concordância na largura entre os caninos e na largura entre os primeiros molares foram baixos na comparação entre a tomografia computadorizada de feixe cônico e os demais instrumentos. Na largura entre o primeiro e o segundo pré-molar, todas as comparações apresentaram valores de concordância aceitáveis. Valores de concordância aceitáveis também foram obtidos ao comparar a profundidade do palato na região do segundo pré-molar com o uso de um divisor de arco dentro da cavidade oral e no gesso. Conclusão A maioria dos instrumentos apresentou concordância satisfatória nas medidas relacionadas ao plano transverso do palato duro. Porém, quando avaliado o plano vertical, apenas o divisor de arco aplicado tanto no gesso quanto na cavidade oral apresentou concordância ideal.

Precisão de réguas endodônticas milimetradas e orifício calibrador, e avaliação da regularidade da superfície do orifício calibrador / Accuracy of endodontic millimeter rulers and calibrator hole, and evaluation of the regularity of the calibrator hole surface

Objetivo: O objetivo desse artigo foi avaliar a precisão das porções milimetrada e calibradora das réguas endodônticas, e avaliar a regularidade da superfície dos orifícios calibradores. Métodos: A porção milimetrada das réguas Angelus, Maillefer, Maquira, Microdont e Prisma foi avaliada com paquímetro eletrônico digital. Os orifícios calibradores da Maillefer, Prisma e Angelus foram medidos com um projetor de perfil. A regularidade da superfície dos orifícios calibradores foi classificada em S1 ­ sem irregularidades ou S2 ­ com regularidades. A análise de precisão das porções milimetrada e calibradora foi realizada com o teste t (p=0,05); e as frequências dos tipos de superfície, com o teste do qui-quadrado (p<0,05). Resultados: A Maillefer foi a única régua endodôntica com precisão em todos os comprimentos e orifícios. A Prisma apresentou estatisticamente mais orifícios do tipo S2, quando comparada com outras réguas endodônticas avaliadas (p<0,05). Não houve diferença estatisticamente significativa entre Angelus e Maillefer (p>0,05). Conclusão: A Maillefer apresentou precisão nas porções milimetrada e calibradora. As réguas endodônticas da Angelus não foram precisas em nenhum comprimento da parte milimetrada e não foram precisas na maioria dos orifícios calibradores. A régua endodôntica Prisma mostrou significativamente mais orifícios calibradores com irregularidades na superfície do que Angelus e Maillefer. Destaca-se a necessidade de controle de qualidade e padrões específicos para fabricação das réguas endodônticas (AU).

Objective: The aim was to evaluate the accuracy of the millimeter and calibration portion and evaluate the regularity of the calibrator orifice surfaces of the endodontic rulers. Methods: The millimeter portion of the Angelus, Maillefer, Maquira, Microdont and Prisma rulers was evaluated with an electronic digital caliper. The calibration holes of the Maillefer, Prisma and Angelus were measured with Profile Projector. The surface regularity of calibration holes was evaluated and classified in S1- without irregularities and S2- with irregularities. The accuracy analysis of the millimeter and calibration was performed with T-Test (p=0.05) and the frequencies of the surface types with Chi-square (p<0.05). Results: The Maillefer was the only rulers with accuracy in all lengths and holes. Prisma presented statistically more S2 type holes when compared with other endodontic rulers evaluated (p <0.05). There was no statistically significant difference between Angelus and Maillefer (p> 0.05). Conclusion: The Maillefer presented accuracy in the millimeter and calibration portion. Angelus endodontic rulers were not accurate at any rated length of the millimeter portion and it was not accurate in most calibration holes evaluated. Prisma endodontic ruler showed significantly more calibration holes with irregular surfaces than Angelus and Maillefer. We emphasize the need for quality control and specific standards for endodontic rulers manufacturing (AU).

Dimensional Accuracy Comparison of Physical Models Generated by Digital Impression/3D-Printing or Analog Impression/Plaster Methods

ABSTRACT: This study aimed to compare the trueness and precision of physical models manufactured chairside (intraoral scanner and 3D printed) or by plaster models obtained using impression with alginate or addition silicone. A full- arch stainless steel die was impressed to obtain ten physical models for each group. The models were measured in a stereomicroscope, considering four linear distances. To assess the precision accuracy, an analysis of the measurement variability was carried out, identified by the coefficients of variation and by the Levene's test to compare the groups. To analyze trueness, the data average was subtracted from the database and compared considering alpha as 5 %. Considering precision, the higher dispersion of data occurred in the models obtained with silicone impression. And for trueness, Kruskal Wallis and Dunn tests results did not indicate differences between the groups in the anteroposterior linear distances (p> 0.05). Only in anterior transverse distance obtained through TRIOS (0.31 mm), it presented lower accuracy compared to the models from silicone impression (0.13 mm); however, at transverse posterior distance, the models from silicone impression showed the lowest accuracy (p 0.05). The physical dental models obtained by digital and analog workflows showed acceptable dimensional accuracy expressed by high precision and trueness. There is no difference between the evaluated intraoral scanner systems and the impression materials for the full-arch impression.

RESUMEN: Este estudio tuvo como objetivo comparar la veracidad y precisión de modelos físicos fabricados en la clínica dental (escáner intraoral e impreso en 3D) o por modelos de yeso obtenidos mediante impresión con alginato o silicona de adición. Una matriz de acero inoxidable de arco completo fue impresa para obtener diez modelos físicos para cada grupo. Los modelos se midieron en un estereomicroscopio, considerando cuatro distancias lineales. Se realizó un análisis de la variabilidad de la medida para evaluar la precisión, identificada por los coeficientes de variación y por la prueba de Levene para comparar los grupos. Para analizar la veracidad, el promedio de los datos se restó de la base de datos y se comparó considerando alfa como 5 %. Considerando la precisión, la mayor dispersión de datos ocurrió en los modelos obtenidos con impresión de silicona. Y para la veracidad, los resultados de las pruebas de Kruskal Wallis y Dunn no indicaron diferencias entre los grupos en las distancias lineales anteroposteriores (p> 0,05). Solo en la distancia transversal anterior obtenida mediante TRIOS (0,31 mm) presentó menor precisión en comparación con los modelos de impresión de silicona (0,13 mm); sin embargo, la distancia transversal posterior, los modelos de impresión de silicona mostraron la menor precisión (p 0,05). Los modelos dentales físicos obtenidos mediante flujos de trabajo digitales y analógicos mostraron una precisión dimensional aceptable expresada por alta precisión y veracidad. No se observó diferencia entre los sistemas de escáner intraoral evaluados y los materiales de impresión para la impresión de arco completa.

Study on the transverse relationship of the mandible between different skeletal vertical patterns in patients with skeletal ClassⅠ malocclusion / 口腔疾病防治

Objective@#To analyze the correlation between skeletal vertical patterns and mandibular dental arch width, basal arch width and the dental buccolingual inclination of patients with skeletal ClassⅠ@*Methods@#The CBCT data of 62 skeletal ClassⅠ malocclusion patients were collected and divided into a high-angle group with 19 cases, a mean-angle group with 22 cases, and a low-angle group with 21 cases according to the GoGn-SN angle. Mandible 3D reconstruction of the three groups was performed using Dolphin software, and dental arch widths, basal arch widths and buccolingual inclination of canines, first premolars and first molars, were measured and statistically analyzed respectively. @*Redults@#Mandibular dental arch width showed no significant difference among the three groups (P>0.05). The basal arch widths of mandibular canines and first premolars in low-angle group were larger than those in the other groups (P<0.05). The buccolingual inclinations of mandibular canines and first premolars in high-angle group were larger than those in the other groups (P<0.05). The buccolingual inclination and basal arch width of the first molars among the three groups showed no significant differences (P>0.05). Pearson correlation tests showed that the basal arch widths of mandibular canines and first premolars were negatively correlated with GoGn-SN angle. Excluding the influence of dental arch width and basal arch width, there was still a significant positive correlation between the buccolingual inclination of mandibular canines and first premolars and the GoGn-SN angle (P<0.05).@*Conclusion@#The width of the basal bone arch between different skeletal vertical patterns mainly differs in the canine segment and the premolar segment, and the difference in the buccolingual inclination of the teeth is mainly to compensate for the difference in the GoGn-SN angle. In clinical practice, individualized therapy should be adopted according to the differences to achieve the long-term efficacy of correction.

Efficacy of mandibular molar distalization by clear aligner treatment / 中南大学学报(医学版)

OBJECTIVES@#At present, the research on clear aligner of molar distalization mainly focuses on the upper jaw, while the research on mandibular molars is few.This study aims to evaluate the therapeutic effect of mandibular molars distalization with clear aligner via cone beam CT (CBCT) and Dolphin software.@*METHODS@#Twenty cases of mandibular molars with clear aligner were included according to the inclusion and exclusion criteria. CBCT was taken before treatment (T0) and when the first molar was moved in place (T1). Dolphin software was used to measure the effectiveness of molar distalization. Three-dimensional changes in direction and the impact on the incisors and facial soft and hard tissues were evaluated.@*RESULTS@#The effective rates of crown and root distalization of the second and first mandibular molars were 74%, 49%, and 71%, 47%, respectively. The second and first molars were both the distal buccal cusp with the largest distalization [(2.15 ± 0.91) mm and (1.85±1.09) mm], respectively, with significant difference between the T0 and T1 (@*CONCLUSIONS@#Clear aligner can effectively move mandibular molars farther, the crown is more effective than the root, and it is tilted. The second mandibular molar is more effective than the first mandibular molar in its distant displacement and three-dimensional changes. Molar distalization causes minor changes in mandibular incisors and facial soft and hard tissues.

Extended-pour and conventional alginates: effect of storage time on dimensional accuracy and maintenance of details

ABSTRACT Objective: This study aimed to evaluate the dimensional stability and maintenance of details of conventional and high stability alginates up to 5-day storage. Methods: Two types of alginates were selected (n=10) for this study, conventional (Hydrogum) and high stability alginates (Hydrogum 5), which were produced with the aid of a cylindrical metal block and a ring-shaped metal mold (Specifications 18, 19, and 25, ANSI/ADA). Ten images were obtained from the molds for the dimensional stability test, which were taken immediately after their production and at each different storage periods (15 min, 24 h, 48 h, 72 h, 96 h, and 120 h) by a digital camera. The specimens were kept hermetically sealed in plastic bags (23°C) and then used to obtain 140 (n=70) dental stone models, used in the detail reproduction test, in which the angular accuracy of three grooves (20 µm, 50 µm, and 75 µm) was observed at each period. The details reproduction accuracy was classified using a predetermined score classification. Measurements of dimensional changes were made in the Corel DRAW X6 program. The data were submitted to the Student's t-test (α?#8197;= 0.05). Results: A statistically significant difference concerning the size of the matrix was observed after 24h for both alginates, and a statistically significant negative linear dimensional change (contraction) was verified after 24 h of storage (1.52% for the high stability alginate, and 1.32% for the conventional alginate). The high stability alginate kept the full details for 72 hours, while the conventional alginate, for 24 h. Both alginates reproduced the 75 µm groove at all storage periods. Conclusion: Impressions made with both alginates presented satisfactory clinical results when the alginates were immediately poured.

RESUMO Objetivo: O presente estudo teve como objetivo avaliar a estabilidade dimensional e manutenção de detalhes de alginatos convencionais e de alta estabilidade por até 5 dias de armazenamento. Métodos: Para esse estudo, foram selecionados dois tipos de alginatos: convencional (Hydrogum) (n = 10) e de alta estabilidade (Hydrogum 5) (n = 10), sendo produzidos com o auxílio de um bloco metálico cilíndrico e um molde metálico em forma de anel (especificações 18, 19 e 25, ANSI/ADA). Para o teste de estabilidade dimensional, dez imagens foram obtidas imediatamente e para cada tempo de armazenamento (15 min, 24, 48, 72, 96 e 120 horas), realizadas por câmera digital. As amostras foram mantidas hermeticamente fechadas em sacos plásticos (23°C). Para o teste de reprodução de detalhes, as amostras foram utilizadas para obter 140 (n = 70 por grupo) modelos de gesso, sendo observada a precisão angular de três sulcos (20 µm, 50 µm e 75 µm) para cada período. A precisão da reprodução de detalhes foi classificada usando uma classificação de pontuação predeterminada. As medições das mudanças dimensionais foram feitas no programa Corel DRAW X6. Os dados foram submetidos ao teste t de Student (α = 0,05). Resultados: Foi observada diferença estatística em relação à matriz após 24h para ambos os alginatos. Uma mudança dimensional linear negativa estatisticamente significativa (contração) foi verificada após 24 h de armazenamento (1,52% para alginato de alta estabilidade; 1,32% para alginato convencional). O alginato de alta estabilidade manteve os detalhes completos por até 72 horas, enquanto o alginato convencional, por 24 horas. Os alginatos reproduziram o sulco de 75 µm para todos os períodos. Conclusão: As impressões feitas com ambos os alginatos devem ser imediatamente vazadas para se ter resultados clínicos satisfatórios.

Influence of mandibular positioning on the accuracy and reliability of linear measurements on cone beam CT using different voxels and two software programs / Influência do posicionamento mandibular na acurácia e confiabilidade de medidas lineares em tomografia computadorizada de feixe cônico utilizando diferentes voxels e dois softwares

Objetivo: este estudo avaliou a acurácia e confiabilidadedas medidas lineares em exames detomografia computadorizada de feixe cônico(TCFC), em dois softwares, utilizando diferentesvoxels e variando o posicionamento da mandíbula.Material e Métodos: 10 imagens de TCFC demandíbulas humanas com 25 pontos foram obtidas,usando diferentes protocolos de aquisição(0.250, 0.300, 0.400-mm voxels) e orientações damandíbula (centralizada, rotacionada 10° lateralmentepara direita e esquerda, inclinada 10° para cima e para baixo); 14 medidas foram realizadasnas reconstruções multiplanares nos softwares XoranCate OsiriX. Os achados foram comparadoscom as medidas físicas através de um paquímetrodigital. O teste ANOVA e o coeficiente de correlaçãoforam utilizados com p < 0,05. Resultados:não houve diferença estatisticamente significantequando as medidas foram comparadas em aquisiçõescom diferentes tamanhos de voxels emambos os softwares. A posição da mandíbula nãoinfluenciou nas medidas. Nenhuma diferença foiencontrada quando os valores foram comparadosentre os softwares e o paquímetro digital. Conclusão:as medidas lineares em ambos os softwaresforam confiáveis e acurados comparados a mensuraçãofísica em todos os protocolos. A acuráciae a confiabilidade das mensurações não influenciaramde acordo com as variações de posicionamentoda mandíbula.(AU)

Objective: this study evaluated the accuracy and reliability of linear measurements on cone beam CT (CBCT) scans in two software programs, using different voxels and varying mandible positioning. Material and methods: CBCT images of 10 human mandibles with 25 markers were obtained using different acquisition protocols (0.250, 0.300, 0.400-mm voxels) and mandible orientations (centered, rotated 10° laterally to right and left, tilted 10 up and down); fourteen measurements were carried out on the multiplanar reconstructions in XoranCat and OsiriX Lite software programs. The findings were compared to physical measurements using a digital caliper. ANOVA and correlation coefficient tests were used, at α = 0.05. Results: there was no statistically significant difference when the measurements were compared in acquisitions with different voxel sizes analysed in both software programs. Mandibular positioning changes did not influence the measurements. No differences were found when the values were compared between the software programs and the digital caliper. Conclusion: linear measurements in both programs were reliable and accurate compared with physical measurements when using all acquisition protocols. The accuracy and reliability of the measurements were not influenced by variations in the mandible positioning.(AU)

Uso de scanners intraorais em implantodontia / Uso de los escáneres intrabucales en implantología / Use of intraoral scanners in implantology

RESUMO Introdução: O escâner intraoral é um aparelho que surge como alternativa aos métodos convencionais de moldagem utilizando a técnica de impressão digital. O meio acadêmico vem realizando diversos estudos para avaliar a real efetividade da tecnologia e sua aplicabilidade clínica. Objetivo: Analisar resultados obtidos em estudos sobre escâneres intraorais na área de implantodontia quanto ao tipo de escâneres e acurácia, tempo de trabalho e preferência do operador e do paciente. Métodos: Foram realizadas buscas de artigos nas bases de dados "Pubmed" e "SciELO" utilizando os seguintes descritores: «intraoral AND scanner AND implant¼, «digital AND scanner AND implant¼ e «digital AND impression AND implant¼ em inglês, português e espanhol respectivamente. Os critérios de inclusão foram: artigos de avaliação clínica (in vivo) ou laboratorial (in vitro) que avaliassem o uso da técnica de escaneamento intra-oral para impressão digital de implantes com acesso integral, escritos em português, inglês ou espanhol e publicados a partir de 2013. Análise e integração da informação: Foram encontrados 158 artigos. Após a análise e seleção, 35 artigos foram incluídos, sendo 28 laboratoriais e 7 clínicos. Apesar de limitações na padronização dos estudos, percebemos o potencial e a viabilidade da técnica digital, com resultados clínicos e de acurácia favoráveis e vantagens como redução do tempo e etapas de trabalho, comunicação dinâmica com os laboratórios, preferência de pacientes e estudantes de odontologia e facilidade de incorporação por profissionais já experientes. Conclusões: Estudos laboratoriais indicam que, além de vantagens quanto ao uso de materiais de moldagem, comunicação com os laboratórios e facilidade de manipulação, a técnica digital pode alcançar resultados superiores aos da técnica convencional, assim, a técnica se mostra promissora para a área de implantodontia sendo necessário, contudo, estudos futuros, especialmente in vivo, para avaliar a consistência dos resultados clínicos(AU)

RESUMEN Introducción: El escáner intrabucal es un aparato que surge como una alternativa frente a los métodos convencionales de moldeo, y el medio académico viene realizando diversos estudios para evaluar la real efectividad de esta tecnología y su aplicabilidad clínica. Objetivo: Analizar resultados obtenidos en estudios sobre escáneres intrabucales en el área de implantología en cuanto a los tipos de escáneres y la exactitud, tiempo de trabajo y preferencia del operador y del paciente. Métodos: Se realizaron búsquedas en las bases de datos "PubMed" y "SciELO" utilizando los siguientes descriptores: "intraoral AND scanner AND implant", "digital AND scanner AND implant" and "digital AND impression AND implant" en inglés, portugués y español, respectivamente. Los criterios de inclusión fueron: artículos clínicos o de laboratorio para evaluar el uso de la técnica de escaneamiento digital de los implantes, con acceso completo al artículo, escrito en portugués, inglés o español y publicados desde 2013. Análisis e integración de la información: Se encontraron 158 artículos. Después del análisis y selección, 35 artículos fueron incluidos, siendo 28 de laboratorio y 7 clínicos. A pesar de las limitaciones en la estandarización de los estudios, percibimos el potencial y la viabilidad de la técnica digital, con resultados clínicos y de precisión favorables y ventajas como reducción del tiempo y etapas de trabajo, comunicación dinámica con los laboratorios, preferencia de pacientes y estudiantes de odontología y facilidad de incorporación de profesionales experimentados. Conclusiones: Los estudios de laboratorio indican que, además de ventajas en cuanto al uso de materiales de moldeo, comunicación con los laboratorios y facilidad de manipulación, la técnica digital puede alcanzar resultados superiores a los de la técnica convencional, por lo que el uso de escáneres intrabucales se muestra prometedor para el área de implantología siendo necesario, sin embargo, estudios futuros, especialmente in vivo, para evaluar la consistencia de los resultados clínicos(AU)

ABSTRACT Introduction: Intraoral scanners are devices that emerged as an alternative to conventional impression methods. A variety of studies have been conducted to evaluate the actual effectiveness of this technology and its clinical applicability. Objective: Analyze the results obtained by studies about intraoral scanners in the area of implantology in terms of types, accuracy, working time, and operator and patient preference. Methods: A search was conducted in the databases PubMed and SciELO using the following descriptors: "intraoral AND scanner AND implant", "digital AND scanner AND implant" and "digital AND impression AND implant" in English, Portuguese and Spanish. The inclusion criteria were the following: clinical or laboratory papers evaluating the use of digital implant scanning technique, full access to the paper, written in Portuguese, English or Spanish and published as of the year 2013. Data analysis and integration: Of the 158 papers obtained and analyzed, 35 were selected: 28 laboratory and 7 clinical. Despite the limitations in the standardization of the studies, we perceive the potential and viability of the digital technique, with favorable clinical and accuracy results, as well as advantages such as a reduction in work time and stages, dynamic communication with laboratories, preference by patients and dental students and ease of technical incorporation by experienced dentists. Conclusions: Laboratory studies indicate that, in addition to the advantages concerning the use of impression materials, communication with laboratories and ease of manipulation, the digital technique may achieve better results than conventional impression techniques. The use of intraoral scanners is therefore a promising technique for the area of ​​implantology. However, further studies shouldbe conducted, especially in vivo, to evaluate the consistency of the clinical results obtained(AU)

Comparison of the accuracy of two⁃dimensional and three⁃dimensional photography in the facial measuremenof patients with unilateral cleft lip t / 口腔疾病防治

Objective@#To compare the measurement accuracy of two⁃dimensional (2D) photography and three⁃di⁃mensional (3D) photography in the analysis of the asymmetric appearance of children with cleft lip and palate and the influence of the severity of asymmetric deformity on the accuracy of facial measurement to guide clinical measurement work@* Methods@#Children with unilateral cleft lip were enrolled in this prospective study. Seven parameters⁃⁃the devia⁃tion of the pronasale, subnasale, and labrale superius, as well as the cleft/noncleft ratio of the width of nostrils, length and height of lateral lips and height of columella⁃were measured with Vernier calipers as the gold standard. Traditional 2D photography and 3D stereophotogrammetry photos were taken and measured. The extent of cleft malformation is indi⁃cated by the ratio of the cleft side to the noncleft side. The error size is represented by the ratio difference between two⁃dimensional photography or stereophotogrammetry with the ratio of the gold standard@* Results@#Thirteen patients were eventually recruited. The measurement results of the ratio of lateral lip height by 2D photography tended to be larger (P＝0.019), and the measurement results of the ratio of columella height tended to be smaller (P＝0.008). The measure⁃ment results of the deviation of the subnasale by stereophotogrammetry tended to be smaller (P＝0.003). The pronasale deviation (P＝0.022) with two⁃dimensional photography, the deviation of the labrale superius (P＝0.025) and the ratio of lateral lip length (P＝0.036) with stereophotogrammetry had a significant negative correlation with the extent of cleft malformation@* Conclusion@#Both two⁃dimensional photography and stereophotogrammetry have errors and biases that underexaggerate or overexaggerate the extent of cleft malformation, and some errors may increase with the decrease in the extent of cleft malformation. When applying two⁃dimensional and three⁃dimensional photography to analyze cleft lip and palate deformities, these biases should be considered to evaluate the face more objectively

Dimensional Accuracy of 3D-printed Models of the Right First Metacarpal Bones of Cadavers

Background@#The use of 3D printing in medical education, prosthetics, and preoperative planning requires dimensional accuracy of the models compared to the replicated tissues or organs. Objective. To determine the dimensional accuracy of 3D-printed models replicated from metacarpal bones from cadavers. @*Methods@#Fifty-two models were 3D-printed using fused deposition modeling (FDM), stereolithography (SLA), digital light processing (DLP), and binder jetting method from 13 right first metacarpal bones of cadavers from the College of Medicine, University of the Philippines Manila. Six dimensional parameters of the 3D-printed models and their control bones were measured using 0.01 mm calipers — length, midshaft diameter, base width, base height, head width, and head height. Mean measurements were compared using non-inferiority testing and multidimensional scaling.@*Results@#Mean measurements of the 3D-printed models were slightly larger than their control bones (standard deviation range: 1.219-4.264; standard error range, 0.338-1.183). All models were found to be at least 90% accurate and statistically non-inferior compared to control bones. DLP-printed models were the most accurate (base width, 99.62 %) and most similar to their control bone (–0.05, 90% CI –0.34, 0.24). Through multidimensional scaling, DLP-printed models (coordinate = 0.437) were the most similar to the control bone (coordinate = 0.899).@*Conclusion@#The 3D-printed models are dimensionally accurate when compared to bones.

Effect of slice inclination and object position within the field of view on the measurement accuracy of potential implant sites on cone-beam computed tomography

PURPOSE: The purpose of this study was to evaluate the accuracy of linear measurements in the horizontal and vertical dimensions based on object position and slice inclination in cone-beam computed tomography (CBCT) images.MATERIALS AND METHODS: Ten dry sheep hemi-mandibles, each with 4 sites (incisor, canine, premolar, and molar), were evaluated when either centrally or peripherally positioned within the field of view (FOV) with the image slices subjected to either oblique or orthogonal inclinations. Four types of images were created of each region: central/cross-sectional, central/coronal, peripheral/cross-sectional, and peripheral/coronal. The horizontal and vertical dimensions were measured for each region of each image type. Direct measurements of each region were obtained using a digital caliper in both horizontal and vertical dimensions. CBCT and direct measurements were compared using the Bland-Altman plot method. P values <0.05 were considered to indicate statistical significance.RESULTS: The buccolingual dimension of the incisor and premolar areas and the height of the incisor, canine, and molar areas showed statistically significant differences on the peripheral/coronal images compared to the direct measurements (P<0.05). Molar area height in the central/coronal slices also differed significantly from the direct measurements (P<0.05). Cross-sectional images of either the central or peripheral position had no marked difference from the gold-standard values, indicating sufficient accuracy.CONCLUSION: Peripheral object positioning within the FOV in combination with applying an orthogonal inclination to the slices resulted in significant inaccuracies in the horizontal and vertical measurements. The most undesirable effect was observed in the molar area and the vertical dimension.

Three-dimensional analysis of the mandible with impacted mandibular second molar / 华西口腔医学杂志

OBJECTIVE@#To study the developmental and morphological characteristics of the mandible in patients with impacted mandibular second molar and to predict the possible trend of mandibular development via three-dimensional (3D) measurement and analysis.@*METHODS@#A total of 88 cases of impacted group and 88 cases of control group were screened out. 3D measurements were performed by using Mimics software. A total of 23 landmark points and 17 measurements were determined. The measurements were analyzed by t-test.@*RESULTS@#The mandible length, the space between the first molars, the space between mandibular angles, and the width between the first molars in the impacted group were lower than those in the control group (P<0.05). Moreover, the value of the submandibular angle was higher than that in the control group (P<0.05).@*CONCLUSIONS@#The impacted mandible of patients with mandibular second molar showed lack of sagittal and width development, and the impacted mandibular second molar was a manifestation of its degeneration.

Measurement of wound area for early analysis of the scar predictive factor / Mensuração da área de feridas para análise precoce do fator preditivo cicatricial / Medición del área de heridas para el análisis temprano del factor predictivo de cicatriz

Objective: to evaluate the use of the 2D-FlexRuler as a facilitating tool for the early calculation of the predictive scar factor of chronic wounds. Method: a descriptive study with a quantitative, experimental, longitudinal and prospective approach. The sample consisted of 22 outpatients. 32 chronic wounds were analyzed. The wound edges were identified and drawn on the 2D-FlexRuler. The calculations of the areas of chronic wounds were obtained by manual, traditional methods, by software and Matlab algorithm. These areas were compared with each other to determine the efficiency of the proposed ruler in relation to traditional methods. Results: the calculation of the wound area by the traditional method and Kundin's coefficient show average errors greater than 40%. The manual estimation of the area with the 2D-FlexRuler is more accurate in relation to traditional measurement methods, which were considered quantitatively disqualified. When compared with the reference method, for example, the Klonk software, the data obtained by 2D-FlexRuler resulted in an error of less than 1.0%. Conclusion: the 2D-FlexRuler is a reliable metric platform for obtaining the anatomical limits of chronic wounds. It facilitated the calculation of the wound area under monitoring and allowed to obtain the scar predictive factor of chronic wounds with precocity in two weeks.

Objetivo: avaliar o uso da régua 2D-FlexRuler como ferramenta facilitadora para o cálculo precoce do fator preditivo cicatricial de feridas crônicas. Método: estudo descritivo com abordagem quantitativa, experimental, longitudinal e prospectiva. A amostra foi de 22 pacientes ambulatoriais. Foram analisadas 32 feridas crônicas. As bordas das feridas foram identificadas e desenhadas na 2D-FlexRuler. Os cálculos das áreas das feridas crônicas foram obtidos pelos métodos manuais, tradicionais, por softwares e algoritmo Matlab. Essas áreas foram comparadas entre si para determinar a eficiência da régua proposta em relação aos métodos tradicionais. Resultados: o cálculo da área da ferida pelo método tradicional e coeficiente de Kundin demonstram erros médios maiores do que 40%. A estimativa manual da área com a 2D-FlexRuler é mais exata em relação aos métodos tradicionais de medição, os quais foram considerados quantitativamente desqualificados. Quando comparada com o método de referência, i.e., o software Klonk, os dados obtidos pela 2D-FlexRuler resultaram em um erro menor que 1,0%. Conclusão: a régua 2D-FlexRuler é uma plataforma métrica confiável para a obtenção dos limites anatômicos de feridas crônicas. Facilitou o cálculo da área da ferida sob monitoramento e permitiu obter o fator preditivo cicatricial de feridas crônicas com precocidade em duas semanas.

Objetivo: evaluar el uso de la regla 2D-FlexRuler como herramienta facilitadora para el cálculo temprano del factor predictivo de cicatrices en heridas crónicas. Método: estudio descriptivo con enfoque cuantitativo, experimental, longitudinal y prospectivo. La muestra consistió en 22 pacientes ambulatorios. Se analizaron 32 heridas crónicas. Los bordes de la herida fueron identificados y dibujados en 2D-FlexRuler. Los cálculos de las áreas de heridas crónicas se obtuvieron por métodos manuales, tradicionales, por software y algoritmo Matlab. Estas áreas se compararon entre sí para determinar la eficiencia de la regla propuesta en relación con los métodos tradicionales. Resultados: el cálculo del área de la herida por el método tradicional y el coeficiente de Kundin muestran errores promedio superiores al 40%. La estimación manual del área con 2D-FlexRuler es más precisa en relación con los métodos de medición tradicionales, que se consideraron descalificados cuantitativamente. Al ser comparados con el método de referencia, es decir, el software Klonk, los datos obtenidos por 2D-FlexRuler arrojaron un error de menos del 1,0%. Conclusión: la regla 2D-FlexRuler es una plataforma métrica confiable para obtener los límites anatómicos de las heridas crónicas. Facilitó el cálculo del área de la herida bajo monitoreo y permitió obtener el factor predictivo de cicatriz de heridas crónicas con precocidad en dos semanas.

Reliability of Two Methods of Evaluation of the Apical Limit of Obturation of Root Canals of Primary Teeth: A Pilot Study

Abstract Objective: To verify the concordance in the evaluation of the apical limit of obturation (ALO) in filled root canals of primary teeth between digital and visual methods. Material and Methods: Twenty periapical radiographs of endodontically treated primary teeth were digitalized and evaluated by an endodontics specialist (E1), a PhD pediatric dentist (E2), and a MSc general dentist (E3). Calibrated evaluators (Kappa = 1.00) analysed the images in a light-isolated environment two times (D1 and D2) with a one-week interval between evaluations. ALO scores were categorized as overfilled, flush-filled and underfilled. Results: The intra-rater reliability between methods was 0.82 (D1) and 0.75 (D2) for E1, 0.93 (D1 and D2) for E2, and 0.94 (D1 and D2) for E3. Inter-rater reliability ranged from 0.71 (E1 × E3) and 1.00 (E1 × E2) for the visual method to 0.76 (E1 × E3) and 0.88 (E1 × E2) for the digital method. Spearman correlation coefficients showed a similar ranking among the evaluators. There was greater disagreement among the underfilled and ideal scores. For all evaluators, the digital method favoured the identification of the ideal score. Conclusion: Both methods are suitable for the determination of the ALO of filled primary teeth and can be used in clinical practice.

Three-dimensional measurement and analysis of nasolabial soft tissue changes following maxillary anterior movement by Le Fort osteotomy / 上海交通大学学报（医学版）

Objective • To evaluate nasolabial soft tissue changes of Chinese patients with malocclusion after maxillary anterior movement by Le Fort osteotomy with three-dimensional measurement. Methods • From Jan. to Dec. 2017, 37 patients with skeletal Class III malocclusion from Department of Oral and Craniomaxillofacial Surgery of Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, who underwent maxillary Le Fort osteotomy for anterior movement and bilateral sagittal split ramus osteotomy (bi-maxillary orthognathic surgery), were included. A full cranial spiral CT scan and three-dimensional facial soft tissue images were performed within 1 week before and 6 months after operation. Landmarks, relative distance and angle of nasolabial soft tissue were located and measured by 3dMD vultus software, and the differences before and after operation were compared. Results • After bi-maxillary orthognathic surgery, the alar width increased by an average of 0.82 mm, the subalar width increased by an average of 1.07 mm, the upper lip length increased by an average of 1.41 mm, the nasolabial angle increased by an average of 3.09, and the pronasal angle decreased by an average of 1.51(all P<0.05), while nasal height, nasal length and nasal frontal angle were basically stable. Conclusion • After the maxillary Le Fort I osteotomy for anterior movement, the face of patient with malocclusion is improved, and the nasolabial soft tissue is also changed.