Precisão dos escaneamentos intraorais e modelos 3D, com diferentes escâneres e softwares: revisão sistemática / Accuracy of intraoral scanning and 3D models, with different scanners and software: systematic review

Objetivo: Esta revisão sistemática investigou se a precisão dos escaneamentos intraorais e modelos 3D com diferentes escâneres e softwares, é suficiente para os clínicos aceitarem e implementarem as novas tecnologias como critério de diagnóstico e planejamentos dos tratamentos. Material e métodos: Protocolo PROSPERO número CRD42020218151. Duas revisoras realizaram uma pesquisa avançada de banco de dados eletrônico, sem restrição de idioma ou data, no MEDLINE/PubMed; Embase; BVS/LILACS; Scopus; Cochrane Library; Google Scholar e Web of Science até janeiro de 2021. Os estudos foram escolhidos por título e resumo para triagem, de acordo com os seguintes critérios de inclusão: Estudos Clínicos in vivo e in vitro (pacientes, modelos de gesso de pacientes e manequins simulando bocas humanas) com os diferentes softwares e técnicas de escaneamento intraoral comparando a acurácia, fidelidade e/ou precisão como desfecho dos escaneamentos intraorais, dos modelos virtuais em 3D com modelos de gesso; com um mínimo de 5 pacientes escaneados sem limite de idade ou gênero; texto completo acessível; nos estudos de coorte, transversais e caso-controle. Após a leitura do texto completo os artigos foram excluídos de acordo com os seguintes critérios: 1) estudos com menos de 5 pacientes; 2) estudos em animais; 3) revisão sistemática, descrição de técnica, intervenções, protocolos; 4) escaneamentos por Ressonância Magnética ou Tomografia computadorizada; 5) estudos em que não foram utilizados scanners intraorais. Resultados. Dos 4410 estudos inicialmente identificados, 16 preencheram os critérios de inclusão. O guia PRISMA foi utilizado para redação da revisão e a ferramenta ROBINS-1 da Cochrane foi utilizada para análise de viés. Os estudos incluídos na sua maioria mostraram diferenças estatisticamente significativas entre os resultados das moldagens convencionais e digitais, porém também demonstraram que as diferenças não têm significância clínica. Conclusões: Esta revisão sistemática permitiu levantar dados que demonstraram que os escaneamentos intraorais não são superiores às moldagens convencionais, mas de acurácia equivalente com confiabilidade para o uso das imagens digitais conseguidas por escaneamento intraoral e dos modelos digitais provenientes destes escaneamentos.

Influence of type of restorative materials and surface wetness conditions on intraoral scanning accuracy.

OBJECTIVES: To assess the influence of different restorative materials and surface wetness on intraoral scanning accuracy. METHODS: Reference casts with an extracted second premolar and first and second molar were digitized (L2). Four groups were established according to the material of the first molar: natural tooth (control), zirconia (Z), lithium disilicate (LD), and nanoceramic resin crown (NC). Four subgroups were developed: dry, low-, mild-, and high-wetness subgroups (n = 15). All the scans were completed by using an intraoral scanner (TRIOS 3). In the control-dry subgroup, the reference cast was dry. In the control-low subgroup, artificial saliva was sprayed with a 1 mL/min volumetric flow for 4 s. In the control-mild and control-high subgroups, the same procedures as in the control-low subgroup were performed, but with a volumetric flow of 4 and of 8 mL/min, respectively. In the Z, LD and NC groups, each crown was fabricated with its respective material. Trueness was analyzed using 2-way ANOVA and Bonferroni tests. The Levene and Bonferroni tests were used to assess precision (α = 0.05). RESULTS: Material (P < .001) and wetness (P < .001) significantly influenced trueness and precision. The mild and high subgroups revealed lower trueness and precision compared with the dry and low subgroups. The control, Z, and LD groups under dry and low wetness conditions showed better trueness compared with the NC group, but the materials tested had no significant precision discrepancies. Under mild wetness conditions, all the materials showed no significant trueness discrepancies. Under high wetness conditions, the LD group demonstrated the best trueness and precision. CONCLUSIONS: The restorative materials and surface wetness tested influenced scanning trueness and precision of the IOS assessed. CLINICAL SIGNIFICANCE: Dried surfaces are recommended to maximize the scanning accuracy values of the IOS tested. Overall, the presence of saliva and dental restorations can reduce the performance of the IOS tested.

Efectividad de tres métodos de desobturación sobre modelos réplica / Effectiveness of three unsealing methods on replica models

El objetivo fue evaluar la eficacia de remoción del material de obturación y el tiempo empleado para la desobturación con tres métodos diferentes, en modelos réplica. Se utilizaron 24 modelos réplica de premolares inferiores instrumentados con sistema Protaper Gold hasta F4, irrigación NaOCl 2,5% y ED-TAC 17%. Obturación termoplastizada sistema Fast Pack Pro. La muestra (n=24) se dividió aleatoriamen-te en tres grupos experimentales (n=8) sometidos a distintos métodos de desobturación. Grupo 1: fresas Gates Glidden II/III y limas Hedstroem. Grupo 2: lima Medium sistema Wave One Gold y punta ultrasóni-ca Ultra X, (Eighteeth). Grupo 3: lima Rotate 35/04 y punta ultrasónica R1 Clearsonic, (Helse). Se midió el tiempo de desobturación. Las piezas se radiogra-fiaron con radiovisiógrafo digital RVG 5200 (Cares-tream), y fueron procesadas con software Image-J. Al analizar cantidad de material de obturación rema-nente, la prueba de Kruskal-Wallis (p<0,05), mostró diferencias estadísticamente significativas entre grupos 2 y 3. Grupo 1 no mostró diferencias signifi-cativas con los otros dos (p>0,05). Al analizar tiempo de desobturación, el test de Kruskal-Wallis no deter-minó diferencias significativas entre grupos 1 y 2 (p>0,05), el grupo 3 tuvo diferencias estadísticamen-te significativas con los grupos 1 y 2 (p<0,05). En con-clusión, ninguno de los sistemas de desobturación evaluados logró eliminar la totalidad del material de obturación. El que combinó limas rotatorias con punta ultrasónica de retratamiento fue el que mos-tró mayor efectividad de remoción y demandó menor tiempo de trabajo (AU)

Objective: to evaluate the effectiveness of obturation material removal and the time that the procedure took, when performing the retreatment with three different methods, in replica models of mandibular premolars. Materials and methods: 24 replica models of lower premolars instrumented with Protaper Gold system up to F4, 2.5% NaOCl irrigation and 17% ED-TAC were used. Thermoplastized sealing with Fast Pack Pro system. The sample (n=24) was randomly divided in three experimental groups (n=8) subjected to different unsealing methods. Group 1: Gates Glid-den burs II and III and Hedstroem files. Group 2: Wave One Gold Medium file system and Ultra X ultra-sonic tip, (Eighteeth). Group 3: Rotate 35/04 file and R1 Clearsonic ultrasonic tip (Helse). Unsealing time was measured. The samples were radiographed with a digital radiovisiograph RVG 5200 (Carestream), and processed with Image-J software. When analyzing the amount of remaining filling material, Kruskal-Wallis test showed statistically significant differences be-tween groups 2 and 3 (p<0,05). Group 1 did not show significant differences with the other two (p>0,05). When analyzing unsealing time, Kruskal-Wallis test determined that there were no significant differ-ences between groups 1 and 2 (p>0,05), but group 3 had statistically significant differences with the other two (p<0.05). None of the unsealing systems evalu-ated managed to eliminate all of the sealing material. The group that combined rotary files with ultrasonic retreatment tip showed the greatest removal effec-tiveness and required less work time (AU)

Métodos para medir asimetrías sagitales y transversales en los modelos de estudio de ortodoncia / Methods to measure sagittal and transverse asymmetries in orthodontic study models

Introducción Para el diagnóstico acertado en el tratamiento de los pacientes de ortodoncia se requiere de una serie de exámenes auxiliares, que son herramientas esenciales en ortodoncia; sin embargo, encontramos cierto grado de dificultad para la valoración de asimetrías dentarias en los hemiarcos de cada arcada dentaria; la importancia de la correcta valoración de las asimetrías es ya ampliamente mencionada en diferentes estudios, porque nos ayudará con la localización co-rrecta, de los dientes en su arcada,al final del tratamiento En la actualidad existe poca literatura sobre los métodos para evaluar y diagnosticar las alteraciones por hemiarcos, especialmente en el plano transversal. Objetivo acer una revisión de literatura sobre los métodos de medición de las asimetrías dentarias intra-arco para poder identificar y cuantificar las alteraciones dentarias en los tres planos del espacio en su respectiva arcada dentaria, el Método para los términos de búsqueda de la información fueron: dental and facial asymmetry, molar asymmetry in ortho-dontics, arch width prediction indices, as well as transverse discrepancies, para tal efecto se empleó Pubmed, Medline, Scielo, Schoolar Google, de los cuales se recopilaron 80 artículos relacionados con nuestro tema de estudio y solo se eligieron 30 artículos y 6 libros de ortodoncia en los que se sustenta este artículo. Resultados En el presente artículo presentamos las herramientas con las que contamos para el diagnóstico de la asimetría dentaria intra-arcos como la placa de Sthmuch y la placa milimetrada de Korkhaus, y finalmente proponemos un método que nos permite cuantificar objetivamente la asimetría en los tres plano del espacio de una manera sencilla, reproducible y de fácil almacenaje en un computador. Conclusión La etapa del diagnóstico es importante porque permitirá obtener la mayor y mejor información de las alteraciones dentarias que presenta el paciente, siendo las alteraciones transversales las más difíciles de cuantificar por que la mayoría de los estudios e índices, ya que solo evidencian las distancias de dientes contra laterales, los cuales son datos limitados pero que aún así contribuyen en el diagnóstico, el método de la placa de Sthmuch, Korkhaus y Bernklau son propuesta para medir las asimetrías dentarias intraarcos, no en tanto es desgastador para el operador y sus resultados objetivos radica en la experiencia del operador; el método KLO nos permite cuantificar objetivamente la falta de sime-tría dentaria en cada arcada de una manera fácil, reproducible y de almacenaje en un computador o en un archivo.

Introduction The correct diagnosis in the treatment of orthodontic patients requires a series of auxiliary examinations, which are essential tools in orthodontics, however we found a certain de-gree of difficulty in assessing dental asymmetries in the hemiarchs of each dental arch; The im-portance of the correct assessment of asymmetries is already widely mentioned in different stud-ies, because it will help us with the correct location of the teeth in their arch, at the end of the treatment. Currently there is little literature on the methods to evaluate and diagnose hemiarchal alterations, especially in the transverse plane. Objective Is to review the literature on the methods of measuring intra-arch dental asymmetries in order to identify and quantify dental al-terations in the three planes of space in their respective dental arch. Method The search terms of the information were: dental and facial asymmetry, molar asymmetry in orthodontics, arch width prediction indices, as well as cross-sectional discrepancies. Pubmed, Medline, Scielo, Schoolar Google, of which 80 articles related to our study topic were collected and only 30 articles and 6 orthodontic books were chosen on which this article is based, Results Also in this article we present the tolos that we have for the diagnosis of intraarch dental asymmetry such as the Sth-much plate and the Korkhaus millimeter plate, and finally we propose a method that allows us to objectively quantify the asymmetry in the three space plan in a simple, reproducible way and easy to store on a computer. Conclusión The stage of diagnosis is important because it will allow obtain-ing the greatest and best information on the dental alterations that the patient presents, being the transversal alterations the most difficult to quantify because most studies and indices, since they only show the distances of Contralateral teeth, which are limited data but still contribute to the diagnosis, the Sthmuch, Korkhaus and Bernklau plate method are proposed to measure intra-arch dental asymmetries, not as it is wearisome for the operator and his patients. objective results lies in the experience of the operator; The KLO method allows us to objectively quantify the lack of dental symmetry in each arch in an easy, reproducible way that can be stored on a computer or in a file.

Evaluation of an open access generic 3D software for Orthodontic diagnosis and treatment planning

Aim: To evaluate the accuracy and the validity of orthodontic diagnostic measurements, as well as virtual tooth transformations using a generic open access 3D software compared to OrthoAnalyzer (3Shape) software; which was previously tested and proven for accuracy. Methods: 40 maxillary and mandibular single arch study models were duplicated and scanned using 3Shape laser scanner. The files were imported into the generic and OrthoAnalyzer software programs; where linear measurements were taken twice to investigate the accuracy of the program. To test the accuracy of the program format, they were printed, rescanned and imported into OrthAnalyzer. Finally, to investigate the accuracy of editing capabilities, linear and angular transformation procedures were performed, superimposed and printed to be rescanned and imported to OrthoAnalyzer for comparison. Results: There was no statistically significant difference between the two groups using the two software programs regarding the accuracy of the linear measurements (p>0.05). There was no statistically significant difference between the different formats among all the measurements, (p>0.05). The editing capabilities also showed no statistically significant difference (p>0.05). Conclusion: The generic 3D software (Meshmixer) was valid and accurate in cast measurements and linear and angular editing procedures. It can be used for orthodontic diagnosis and treatment planning without added costs

Estudo do nível de conhecimento e interesse do cirurgião dentista no diagnóstico e tratamento da síndrome da apnéia/hipopnéia obstrutiva do sono (SAHOS) / Study of the level of knowledge and interest of the dental surgeon in the diagnosis and treatment of obstructive sleep apnea/hypopnea syndrome (OSAHS)

Atualmente, o tratamento do ronco primário e da Síndrome da Apnéia/Hipopnéia Obstrutiva do Sono (SAHOS)1 através de aparelhos intra-orais (AIO) tem recebido a atenção dos pesquisadores pela comprovada eficácia destes dispositivos. Os aparelhos mais indicados são os reposicionadores de mandíbula que promovem um avanço mandibular, afastando os tecidos da orofaringe superior, o que evita a obstrução parcial ou total da área. Sua indicação é para casos de ronco primário e apnéias leves e moderadas2, no entanto é necessário que os candidatos apresentem número de dentes suficientes com saúde periodontal para a ancoragem do aparelho. Por ser uma doença de consequências sistêmicas graves, o tratamento da SAHOS é em sua essência de responsabilidade do médico especialista na área, porém o cirurgião dentista deve ter conhecimento para diagnosticar e tratar, quando o AIO for a opção terapêutica. A interpretação da polissonografia, exame que diagnostica e conduz para a escolha correta do tratamento, e dos dados cefalométricos são os principais quesitos ao Cirurgião Dentista que se propõe a tratar portadores da SAHOS. Nesse trabalho foi elaborado um questionário e aplicado aos cirurgiões dentistas de três diferentes cidades do Estado de São Paulo para que fosse possível avaliar o conhecimento desses profissionais a respeito do diagnóstico e tratamento da SAHOS. 70 Cirurgiões Dentistas foram entrevistados e os resultados mostraram que 70% destes têm interesse em trabalhar com os AIOs. Esse grupo se relacionou estatisticamente significante com aqueles que afirmaram já terem sido alguma vez questionado por algum paciente a respeito desse tratamento. Quanto à criação de uma especialidade para essa área, os profissionais da área de prótese e implante se mostraram mais interessados. E, do número total de entrevistados, apenas 25% já tiveram contato com esse tipo de aparelho, mas não conhece o protocolo de atendimento para o tratamento desses pacientes(AU)

Currently, the treatment of primary snoring and Obstructive Sleep Apnea/Hypopnea Syndrome (OSAHS)1 through intraoral appliances (OA) has received the attention of researchers due to the proven effectiveness of these devices. The most suitable devices are jaw repositioning devices that promote mandibular advancement, moving the tissues away from the upper oropharynx, which prevents partial or total obstruction of the area. Its indication is for cases of primary snoring and mild to moderate apnea2, however it is necessary that candidates have a sufficient number of teeth with periodontal health to anchor the appliance. As it is a disease with serious systemic consequences, the treatment of OSAHS is, in essence, the responsibility of the specialist in the area, but the dental surgeon must have the knowledge to diagnose and treat, when OA is the therapeutic option. The interpretation of polysomnography, na exam that diagnoses and leads to the correct choice of treatment, and cephalometric data are the main requirements for the Dental Surgeon who proposes to treat patients with OSAHS. In this work, a questionnaire was developed and applied to dentalsurgeons from three different cities in the State of São Paulo so that it was possible to assess the knowledge of these professionals regarding the diagnosis and treatment of OSAHS. 70 Dental Surgeons were interviewed and the results showed that 70% of them are interested in working with AIOs. This group had a statistically significant relationshipwith those who stated that they had already been asked by a patient about this treatment. Regarding the creation of a specialty for this area, professional in the area of ??prosthesis and implant were more interested. And, of the total number of respondents, only 25% have already had contact with this type of device, but do not know the care protocol for the treatment of these patients(AU)

Accuracy of digital auricular impression using intraoral scanner versus conventional impression technique for ear rehabilitation: A controlled clinical trial.

PURPOSE: This research aims to compare the accuracy of different auricular impression techniques used to produce either a mirror image of the unaffected ear or a surgical stent and template for auricular rehabilitation. The research compares two digital ear impression techniques using an Intra-Oral digital Scanner (IOS) (with /without markers) versus a traditional technique using hydrocolloid impression materials. MATERIAL AND METHODS: Eight participants were selected with intact right ears. Patients' right ears were digitally scanned with an IOS, once with resin markers and once without markers. A conventional auricular impression was taken for each participant, which was then scanned using a desktop scanner. The digital IOS technique with markers was set as a reference model. Total 3D deviations between the study groups were calculated using Geomagic control software (software for 3D coordinate measuring technology). An independent sample t-test was used to make comparisons between the two tested groups. RESULTS: The conventional impression and the intraoral scan without markers recorded a mean of 1.4057 ± 0.3581 and 0.7605±0.1469, respectively, of total 3D deviation from the intraoral scan with markers. There was a significant difference in auricular impression accuracy between conventional and intraoral scans without markers. CONCLUSIONS: Using intraoral scanners facilitates impression acquisition and increases the accuracy compared to traditional hydrocolloid impression techniques, which may affect the shape of tissue due to its liability to be compressed by the impression material. Using markers allows for very precise data collection, reducing stitching complications that affect the accuracy of scans taken without markers. CLINICAL SIGNIFICANCE: The proposed technique for auricular digital impression using an intraoral scanner guarantees a fast technique with accurate results in acquiring anatomical data for the rehabilitation of ear defects. This research was registered on clinicaltrials.gov with the following registration number: NCT04893902.

Exploring the mylohyoid area as a reference for three-dimensional digital mandibular superimposition.

INTRODUCTION: the quantification of tooth movements should be obtained at different specific times and compared at different stages for every orthodontic treatment. These movements are generally measured on teleradiographs or casts. The use of Cone Beam Computed tomography (CBCT) for maxillary superimposition is clearly established in the literature, but not well defined for mandibular superimposition. This study aims to explore and evaluate the accuracy of the mylo-hyoid area as a reference for mandibular Digital Dental Cast (DDC) three-dimensional (3D) superimposition. MATERIALS AND METHODS: the study compared mandibular 3D overlays with profile teleradiographs in 30 patients followed at Nice Saint Roch University Hospital. The molar and incisor coordinates on the 3D superimposition based on the mylo-hyoid area were compared to the ones on the 2D lateral cephalogram. Differences between the two methods of superimposition were assessed using paired t-tests. RESULTS: No statistically significant difference was observed between the lateral cephalogram-based and mandibular DDC superimposition methods in 3D sagittal and vertical displacements of the lower first molars and central incisors. CONCLUSION: The study showed the mylo-hyoid area to be an accurate superimposition landmark for the 3D evaluation of mandibular orthodontic tooth displacement. This method is also applicable for patients with conventional orthodontic treatment records. Other studies should be conducted on larger populations, subgroups (malocclusions, therapeutics) and on the use of an intra-oral camera.

Congruencia entre modelos dentales impresos 3D y el archivo digital de origen: estudio in vitro comparativo de 5 impresoras 3D / Congruence between 3D printed dental models and the original digital file: comparative in vitro study of 5 3D printers

Este trabajo tuvo como objetivo conocer la fiabilidad de la impresora 3D (i3D) aditiva por Matriz de Proceso Digital de Luz (MDLP) Hellbot modelo Apolo®, a través de verificar la congruencia dimensional entre las mallas de modelos impresos (MMi) y su correspondiente archivo digital de origen (MMo), obtenido del software de planificación ortodontica Orchestrate 3D® (O3D). Para determinar su uso en odontología y sus posibilidades clínicas, fue comparada entre cinco i3D de manufactura aditiva, dos DLP, dos por estereolitografía (SLA) y una por Depósito de Material Fundido (FDM). La elección de las cinco i3D se fundamentó en su valor de mercado, intentando abarcar la mayor diversidad argentina disponible. Veinte modelos fueron impresos con cada i3D y escaneados con Escáner Intraoral (IOS) Carestream modelo 3600® (Cs3600). Las 120 MMi fueron importadas dentro del programa de ingeniería inversa Geomagic® Control X® (Cx) para su análisis 3D, consistiendo en la superposición de MMo con cada una de las MMi. Luego, una evaluación cualitativa de la desviación entre la MMi y MMo fue realizada. Un análisis estadístico cuidadoso fue realizado obteniendo como resultado comparaciones en 3d y 2d. Las coincidencias metrológicas en la superposición tridimensional permitieron un análisis exhaustivo y fácilmente reconocible a través de mapas colorimétricos. En el análisis bidimensional se plantearon planos referenciados dentariamente desde la MMo, para hacer coincidir las mediciones desde el mismo punto de partida dentaria. Los resultados fueron satisfactorios y muy alentadores. Las probabilidades de obtener rangos de variabilidad equivalentes a +/- 50µm fueron de un 40,35 % y de +/- 100µm un 71,04 %. Por lo tanto, te- niendo en cuenta las exigencias de congruencia dimensional clínicas de precisión y exactitud a las cuales es sometida nuestra profesión odontológica, se evitan problemas clínicos arrastrados por los errores dimensionales en la manufactura (Cam) (AU)

The objective of this study was to determine the reliability of the Hellbot Apollo® model additive 3D printer (i3D) by Matrix Digital Light Processing (MDLP) by verifying the dimensional congruence between the printed model meshes (MMi) and their corresponding digital source file (MMo), obtained from the Orchestrate 3D® (O3D) orthodontic planning software. A comparison was made between five i3D of additive manufacturing, two DLP, two by stereolithography (SLA), and one by Fused Material Deposition (FDM), to determine its use in dentistry and its clinical possibilities. The choice of the five i3D was based on their market value, trying to cover most of the Argentinean diversity available. Twenty models were printed with each i3D and scanned with Carestream Intraoral Scanner (IOS) model 3600® (Cs3600). The 120 MMi were imported into the reverse engineering program Geomagic® Control X® (Cx) for 3D analysis, consisting of overlaying MMo with each MMi. Then, a qualitative evaluation of the deviation between MMi and MMo. Also, a careful statistical analysis was performed, resulting in 3d and 2d comparisons. Metrological coincidences in three-dimensional overlay allowed a comprehensive and easily recognizable analysis through colorimetric maps. In the two-dimensional analysis, dentally referenced planes were proposed from the MMo, to match the measurements from the same dental starting point. The results were satisfactory and very encouraging. The probabilities of obtaining ranges of variability equivalent to +/- 50µm were 40.35 % and +/- 100µm 71.04 %. Therefore, considering the demands of clinical dimensional congruence, precision, and accuracy to which our dental profession it is subjected, clinical problems caused by dimensional errors in manufacturing (Cam) are avoided (AU)

Occlusal comparison of hand-articulation versus digital articulation in orthognathic surgery.

The aim of the present study was to develop measurement methods to evaluate occlusal differences in digitally-articulated and hand-articulated models in final occlusal planning for orthognathic surgery. A total of 10 (five class II and five class III) previously treated orthognathic cases were analysed by three oral and maxillofacial surgeon investigators, creating a total of thirty cases. Investigators used physical models to create a preferred hand-held final occlusion, which were then scanned and saved utilising a Trios 3® scanner (3Shape). Models were digitally disarticulated and sent back to investigators after a period of at least a month for digital articulation. Novel measurements of dental roll, pitch, and translational differences were performed by an independent engineer using Materialise 3-Matic® software. Statistical analysis was used to evaluate translational differences, the effect of deformity, and inter-investigator variation. A mean (SD) translational difference of 1.58 mm (1.14) mm was seen between the thirty digital and hard-articulated cases analysed. Minimal difference was seen in roll and pitch between hand articulation and digital articulation. A significant translational difference was seen in class III cases compared with class II (p = 0.0006) but not in roll or pitch. There was no significant difference seen between investigators related to translation (p = 0.18), roll (p = 0.09), or pitch (p = 0.17). Digital articulation yielded similar results to hand held in this pilot study. Using measurement techniques described in larger cohorts, its accuracy can be validated using currently available technology.

Avaliação da acurácia dos modelos dentários digitais obtidos para cirurgia ortognática / Assessment of the accuracy of digital dental models obtained for orthognathic surgery

O objetivo deste estudo laboratorial foi avaliar a acurácia dos modelos digitais obtidos por duas técnicas de escaneamento (escâner intraoral - Itero 5d Element® - e escâner de bancada -Straumann ®) de um modelo experimental (Nacional Ossos ®) da arcada superior confeccionada em poliuretano e do modelo de gesso obtido desta arcada. Os pontos A ­ 3mm acima do elemento 17; B ­ 3mm acima do elemento 14; C ­ 3mm acima do elemento 24; D ­ 3mm acima do elemento 27; E ­ cúspide mesiovestibular do elemento 16; F - ponto de contato mais incisal entre os elementos 11 e 21; G - Cúspide mesiovestibular do elemento 26 foram utilizados como referência para as medidas realizadas. As medidas foram realizadas em um software (Geomagic®) de simulação cirúrgica e analisadas quanto a validade e precisão das técnicas de escaneamento utilizadas em todos os grupos (1 a 5). O grupo 1 corresponde ao grupo padrão-ouro; o 2 ao grupo do escaneamento com escâner intraoral do modelo de poliuretano; o 3 ao escaneamento de bancada do modelo; o 4 ao escaneamento com escâner intraoral do modelo de gesso; e 5 ao escaneamento de bancada do modelo de gesso. Na análise da validação, todas as técnicas apresentaram-se válidas quando comparadas ao grupo controle com exceção da medida FG que apresentou diferenças estatisticamente significativas (p<0,05) entre os grupos 1 e 2. A precisão foi avaliada através do índice de correlação intraclasse (CCI) e todas as técnicas apresentaram-se altamente precisas com (CCI) próximo de 1. Desta forma, conclui-se que o escâner intraoral e o escâner de bancada utilizados neste estudo foram confiáveis quando comparados ao grupo controle e que os dois modelos de escâner utilizados se apresentaram com alta precisão (AU).

The objective of this experimental study was to evaluate the accuracy of digital models generated by two scanning techniques (intraoral scanner - Itero 5d Element® - and desktop scanner -Straumann ®) of an experimental model of the upper arch (Nacional Ossos ®) made of polyurethane and the plaster model obtained from this arch. Points A ­ 3mm above element 17; B ­ 3mm above element 14; C ­ 3mm above element 24; D ­ 3mm above element 27; E ­ mesiobuccal cusp of element 16; F - most incisal point of contact between elements 11 and 21; G - Mesiobuccal cusp of element 26 were used as a reference for the measurements performed. The measurements were performed in a surgical simulation software (Geomagic ®) and analyzed for the validity and precision of the scanning techniques used in all groups (1 to 5). Group 1 corresponds to the gold standard group; 2 to the scanning group with intraoral scanner of the polyurethane model; 3 to the desktop scan of the model; 4 to intraoral scanner scanning of the plaster model; and 5 to the desktop scan of the plaster model. In the validation analysis, all techniques showed to be valid compared to the control group, except the FG measure, which showed statistically significant differences (p<0.05) between groups 1 and 2. Precision was assessed using the intraclass correlation(ICC) index, and all techniques were highly accurate with an ICC close to 1. Thus, it is concluded that the intraoral scanner and the bench scanner used in this study were reliable compared to the control group and that the two scanner models used presented themselves with high precision (AU).

CT-Based Modeling of the Dentition for Craniomaxillofacial Surgical Planning.

ABSTRACT: Historically, the accuracy of imaging teeth by computed tomography (CT) has been suboptimal and deemed inadequate for surgical planning of orthognathic procedures. However, recent advances in CT hardware and software have significantly improved the accuracy of imaging occlusal anatomy. This technical note describes a quantitative means of evaluating the accuracy of CT-based modeling of teeth. Three-dimensional models of the dentition were created from a CT scan obtained of a craniomaxillofacial skeleton. Multiple reconstruction algorithms and modeling parameters were applied. The dentition of the same skeleton was scanned using a handheld optical scanning device to serve as the "gold standard." Semi-automated registrations of CT and optically acquired models were performed and deviation analysis was conducted. On average, the deviation of the CT model with the optical scan measured 0.19 to 0.25 mm across the various reconstruction and modeling parameters, with a mean of 0.22 mm. Computed tomography underestimated contours at cusp tips, while overestimating contours in occlusal groves. The use of bone reconstruction algorithms and decreased model smoothing resulted in more accurate models, though greater surface noise. Future studies evaluating the clinical effectiveness of CT-based occlusal splints should take this finding into account.

Accuracy of capturing nasal, orbital, and auricular defects with extra- and intraoral optical scanners and smartphone: An in vitro study.

OBJECTIVES: This in vitro study compares the scanning accuracy of various stationary and portable as well as extra- and intraoral devices for capturing oncological defects. METHODS: A 3D-printed model of a nasal, orbital, and auricular defect, as well as one of an intact auricle, were digitalized (n = 7 per device) with a stationary optical scanner (Pritiface), a portable extraoral optical scanner (Artec Space Spider), two intraoral scanners (Trios 4 and Primescan), and a smartphone (iPhone 11 Pro). For the reference data, the defect models were digitalized using a laboratory scanner (D2000). For quantitative analysis, the root mean square error value for trueness and precision and mean deviations in millimeters were obtained for each defect type. The data were statistically analyzed using two-way ANOVA and Tukey multiple comparison test. For qualitative analysis, a colorimetric map was generated to display the deviation within the defect area and adjacent tissue. RESULTS: Statistically significant interactions were found in the trueness and precision for defect and scanner type. CONCLUSION: The Primescan and Artec Space Spider scanners showed the highest accuracy for most defect types. Primescan and Trios 4 failed to capture the orbital defect. The iPhone 11 Pro showed clinically acceptable trueness but inferior precision. CLINICAL SIGNIFICANCE: The scanning devices may demonstrate varying accuracy, depending on the defect type. A portable extraoral optical scanner is an universal tool for the digitization of oncological defects. Alternatively, an intraoral scanner may be employed in maxillofacial prosthetics with some restrictions. Utilizing a smartphone in maxillofacial rehabilitation should be considered with caution, because it provides inconsistent accuracy.

Accuracy of commercial 3D printers for the fabrication of surgical guides in dental implantology.

OBJECTIVES: To evaluate the accuracy of two different surgical guides (small extent = single implant and large extent = full arch) fabricated by five additive manufacturing technologies (SLA=Stereolithography, DLP= Digital Light Processing, FDM=Fused Deposition Modeling, SLS=Selective Laser Sintering, Inkjet). METHODS: Overall, 72 guides (6 per type) were obtained with the different machines (SLA=Form2; DLP=Rapid Shape D40 and Cara Print 4.0; FDM=Raise 3D Pro2; SLS=Prodways P1000; Polyjet®=Stratasys J750). The guides were surface-scanned with an optical dental scanner, and the resulting files were compared with the initial design files using a surface matching software. Root Mean Square (RMS) and standard deviation were calculated, representing respectively trueness and precision. Kruskall-Wallis non-parametric test was used to compare trueness and precision between small-extent and large-extent guides and 3D printer by pairs. The threshold for significance was α=0.05, except for the comparison of printers by pairs where a Bonferroni-corrected level of 0.0033 was used. RESULTS: Significant differences were observed for trueness and precision between small-extent and large-extent guides, regardless the printer except for DLP (trueness and precision) and SLS (precision). SLA, DLP and Polyjet® technologies showed similar results in terms of trueness and precision for both small-extend and large-extend guides (P>0.05). CONCLUSIONS: The size affected the accuracy of CAD-CAM surgical guides. The different additive manufacturing technologies had a limited impact on the accuracy. CLINICAL SIGNIFICANCE: This study is of clinical interest as it shows that the 3D printing technology (SLA/DLP) has a limited impact on 3D printed surgical guides accuracy. However, the size of the guide can have a significant impact, as small-extent guides were more accurate than large-extent guides.

Final Posttreatment Occlusion in Patients With Unilateral Cleft Lip and Palate.

OBJECTIVE: To evaluate final posttreatment occlusion in patients with complete unilateral cleft lip and palate (cUCLP) by comparing (1) 3 treatment centers, (2) males and females, (3) cleft and noncleft sides, (4) right- and left-sided clefts, and (5) orthodontic treatment with/without orthognathic surgery (OS). DESIGN: Retrospective cohort study. PATIENTS: Blinded posttreatment dental casts of 56 patients (19.4 ± 1.4 years) with cUCLP from 3 centers in Switzerland. MAIN OUTCOME MEASURE: Occlusal assessment using the modified Huddart/Bodenham (MHB) index. RESULTS: Our sample comprised 35 males and 21 females, 46 with left- and 10 with right-sided clefts, of which 32 had undergone OS. The final posttreatment occlusion showed a median MHB score of 0 (interquartile range: -1.0 to 2.0) in the total sample and did not seem to depend on treatment center, sex, or OS. The MHB scores for the anterior buccal and the buccal segments were more negative on the cleft than on the noncleft side (P = .002 and P = .006, respectively). When the cleft was on the left side, the MHB score tended to be more positive in the labial (P = .046) and anterior buccal segments (P = .034). CONCLUSIONS: This study shows a very satisfactory final posttreatment occlusion in patients with cUCLP. The more constricted buccal occlusion on the cleft side emphasizes the attention that should be given in correcting the more medially positioned lesser maxillary segment. The influence of cleft-sidedness should be analyzed further on a sample including more patients with right-sided clefts.

A Digital Approach to Evaluating Tooth Root Position Without Repeated Cone-beam Computed Tomography Scans.

ABSTRACT: The purpose of this report is to introduce a digital approach to evaluating three-dimensional root position without radiation using virtual tooth model which is composed of intraoral-scanned crown and cone-beam computed tomography (CBCT)-scanned root. Successful treatment depends not only on the formulation of a proper initial diagnosis, but also on an accurate assessment of treatment progress, which should include the monitoring and evaluation of tooth and root movements. Although CBCT allows the visualization of the true root position and angulation in three-dimensions, the obtaining of serial CBCT scans for this purpose is associated with concerns regarding radiation exposure. This report introduces a method for monitoring three-dimensional root position following tooth movement during treatment that does not require repeated CBCT scans. This method uses an individual virtual tooth model composed of intraoral-scanned crowns and CBCT-scanned roots. When an evaluation of root positions is needed during treatment, only additional intraoral scan is needed and is integrated into the tooth model; this allows root positions to be estimated without the need for another CBCT scan. The use of a virtual tooth model can potentially allow clinicians to accurately monitor tooth position in routine clinical practice, without the hazards of increased radiation exposure.

Reliability of a digital system for models measurements in BBO grading: A pilot study

ABSTRACT Introduction: Currently, no method is considered effective for the evaluation of digital models in the Certification Examination of the Brazilian Board of Orthodontics (BBO), considering the parameters of the currently used manual method. Objective: Thus, the aim of this study is to verify the reliability of an evaluation method for digital models that could be used in the BBO exam, compared to the gold standard. Methods: Measurements were performed by five previously calibrated examiners. Samples of ten sets of plaster models of the final phase of orthodontic treatment were measured using a manual method (Objective Grading System, OGS). These models were digitized using a 3D scanner and exported to Geomagic Qualify software, in which the measurements were made with the proposed digital method. These measurements were repeated using five models, after fifteen days. The intra-examiner performance with this method was analyzed with a paired t-test, whereas the inter-examiner analysis was carried out with analysis of variance and Tukey's test. To compare the manual and digital methods, a paired t-test and Pearson's correlation analysis were performed. Results: A statistically significant difference was found. The results showed that, when compared to the manual method, the digital method was effective in measuring the OGS in four of the seven variables studied: Marginal Ridge, Overjet, Occlusal Contact, and Interproximal Contact. The variables Alignment, BL inclination, and Occlusal Relationship showed a great amount of dispersion in the findings. Conclusion: Further studies are needed to develop an adequate digital methodology that can be used for all OGS variables.

RESUMO Introdução: Ainda não há um método considerado eficaz para análise dos modelos digitais no exame do Board Brasileiro de Ortodontia (BBO), considerando-se os parâmetros do método manual atual. Objetivo: Assim, o presente estudo objetiva verificar a confiabilidade de um método de avaliação em modelos digitais para o exame do BBO, comparando com o padrão-ouro. Métodos: As medições foram realizadas por 5 examinadores, previamente calibrados. A amostra de 10 pares de modelos de gesso da fase final do tratamento ortodôntico foi medida no método manual (Sistema Objetivo de Avaliação, SOA). Os modelos foram digitalizados por meio de um scanner 3D e exportados para o software Geomagic Qualify, onde foram feitas as medidas no método digital proposto. As medidas foram refeitas em 5 modelos após 15 dias. A análise intraexaminador desse método foi realizada por meio do teste t pareado; já a interexaminadores, feita com ANOVA e teste de Tukey, sendo encontrada diferença estatisticamente significativa. Para a comparação dos métodos manual e digital, foram utilizados o teste t pareado e a correlação de Pearson. Resultados: Uma diferença estatisticamente significativa foi encontrada. Os resultados mostraram que, comparada ao método manual, a metodologia digital mostrou-se eficaz para medição do SOA em quatro das sete variáveis estudadas: Margem interproximal, Sobressaliência, Contato oclusal e Contato interproximal. As variáveis Alinhamento, Inclinação V-L e Relação oclusal mostraram muita dispersão nos achados. Conclusão: Mais estudos são necessários para o desenvolvimento de uma metodologia digital adequada em todas as variáveis do SOA.

Ventajas, desventajas y perspectiva estudiantil de la tecnología del CAD/CAM en el proceso enseñanza-aprendizaje de la educación dental / Advantages, disadvantages and student perspective of CAD/CAM technology in the teaching-learning process of dental education

Introducción: La calidad del aprendizaje en odontología depende en gran medida del tipo y tiempo de práctica que se dedique con estos fines. El diseño y fabricación asistidos por computadora (CAD/CAM) que al ofrecer significativas mejoras en diversos aspectos dentro del modelado dental, advierten con reemplazar al método tradicional del modelado en yeso. Objetivo: Resumir información referente al uso de la tecnología CAD/CAM dentro del proceso enseñanza-aprendizaje de la educación dental. Métodos: Se consultaron las bases de datos MEDLINE y SciELO a través de los términos diseño asistido por computadora, CAD/CAM, enseñanza, educación dental y educación en odontología. Fueron seleccionados 36 documentos publicados a partir del año 2015. Se analizaron las categorías: definición y usos, viabilidad en la educación dental, perspectiva estudiantil, ventajas y desventajas. Análisis e integración de la información: El diseño y manufactura asistidos por computadora es un sistema tecnológico de prototipado rápido que es capaz de materializar modelos digitales diseñados en una interfaz externa, a partir de la información del escaneo realizado. Su incorporación a la educación dental se ha dado de forma dispareja y no sincronizada, debido al gasto económico requerido tanto para la compra del equipo y adaptación de las instalaciones como para la capacitación del personal pertinente. Conclusión: La aplicación del diseño y manufactura asistidos por computadora permite la creación de modelos dentales con grandes beneficios para el entrenamiento práctico. Asimismo, favorece el acercamiento hacia la estandarización de la enseñanza y la objetividad al momento de calificar el trabajo de los estudiantes realizado sobre estos modelos. La barrera económica sigue siendo una fuerte limitante para la implementación del diseño y manufactura asistidos por computadora en la educación dental, pese a ello, los estudiantes suelen presentar aceptación y una gran predisposición para su uso y aplicación(AU)

Introduction: The quality of learning in dentistry depends to a great extent on the type and time of practice devoted to these purposes. Computer-aided design and manufacturing (CAD/CAM) that, by offering significant improvements in various aspects within dental modeling, warns of replacing the traditional method of modeling in plaster. Objective: Summarize information regarding the use of CAD/CAM technology within the teaching-learning process of dental education. Methods: A search was conducted in the databases MEDLINE and SciELO using the descriptors omputer-aided design, CAD/CAM, teaching and dental education. A total 36 documents were selected, published as of the year 2015. The variables considered were definition and uses, viability in dental education, student perspective, advantages and disadvantages. Data analysis and integration: Computer-aided design and manufacturing is a rapid prototyping technological system capable of materializing digital models designed in an external interface based on scanned information. Its incorporation into dental education has been uneven and unsynchronized, due to the expenses required by the purchase of equipment, adaptation of existing facilities and training of the relevant personnel. Conclusion: Computer-aided design and manufacturing makes it possible to create dental models which are very beneficial to practical training. It is also a step forward on the road to standardization of teaching and objectivity when grading the work done by students on these models. Economic limitations continue to strongly handicap the implementation of computer-aided design and manufacturing in dental education. Despite this, students recognize its usefulness and have shown their willingness to apply it(AU)

Patient's perception of intraoral scanning: a comparison between traditional and digital dental impression.

The purpose of this work was to assess the discomfort perceived by the patient during the intraoral scan procedure using the iTero Scanner. A sample of 33 patients was selected on the basis of parameters that identify a complete dentition. All treated patients underwent a traditional polyvinylsiloxane impression with double procedure and an intraoral scan in the same session. Subsequently they were given a questionnaire concerning the discomfort perceived by both procedures. Once the completed questionnaires were obtained, preliminary statistical tests were carried out to check if the distribution of scores assigned by patients to the two procedures differed significantly from a Gaussian distribution. Furthermore, the discomfort/preference indexes for the two procedures were compared using the Wilcoxon test for paired data. Finally, the Spearman correlation test was used. From the results of the preliminary normality tests, it was decided to use nonparametric type tests that gives the intraoral scan procedure more favorable scores relative to a minor discomfort. The use of intraoral scanning and more specifically of the iTero 2.9 scanner (despite a not small wand), represents an option largely preferred by patients in terms of reduction of discomfort and classic discomfort related to relief systems traditional imprint.