Desarrollo de un método digital para la medición y predicción de tamaños dentarios: aplicaciones para determinar alteraciones en el índice de Bolton.

El objetivo de la Tesis Doctoral era introducir y comparar un nuevo Método Digital que basándose en la digitalización de los modelos de estudio de escayola y un software de apoyo permitía calcular la medición de los tamaños mesiodistales de los dientes, longitudes de arcada, discrepancias osedodentarias e índices de Bolton, además de predecir los tamaños de los dientes no erupcionados en dentición mixta.Se seleccionaron 100 pares de modelos de estudio en dentición permanente, 30 correspondían a mujeres y 70 a hombres, con una edad decimal media de 14,8 años (rango 11,2-22,7 años).Procedimos a la medición de los tamaños mesiodistales de todos los dientes de cada uno de los pacientes, por los dos métodos de medición seleccionados.En el Método Tradicional, medimos los tamaños con un calibre tradicional de una sensibilidad de décimas de milímetro, directamente sobre los modelos de escayola, mientras que en el Método Digital, se digitalizaron todos los modelos de estudio con un escáner convencional, para pasar a realizar las mediciones directamente sobre la imagen con el ratón del ordenador como interfase y una sensibilidad de centésimas de milímetros. Posteriormente, con unas tablas seleccionadas y ordenadas por percentiles, se tomaron diferentes dientes (incisivos y molares) como dientes de referencia para determinar el resto de los tamaños mesiodistales de los dientes no erupcionados (caninos y premolares). Los coeficientes de correlación lineal para todos los valores entre el método digital y tradicional fueron cercanos al 1, con ordenadas en el origen de 0 y pendientes de 1, significando con ello, que los datos entre ambos métodos eran idénticos.Para la predicción de los tamaños dentarios, se utilizaron coeficientes de correlación lineal obteniendo muy buenos resultados siendo la combinación del incisivo superior y del molar inferior junta a las listas seleccionadas la mejor combinación para esta predicción.Según una encuesta realizada entre Ortodoncistas españoles y estadounidenses la medición de todos los parámetros anteriores por el método tradicional resultaba laboriosa de realizar y calcular, lo que provocaba su omisión en más de la mitad de los casos. Igualmente, se nos planteaba un problema en casos de Dentición Mixta en los cuales no podíamos realizar una medición directa de los dientes no erupcionados. Por ello, un método digital parecía la opción más adecuada, sencilla, exacta y rápida para el profesional.En ocasiones, nos encontrábamos con modelos de estudio con dientes poco erupcionados donde era difícil localizar los puntos de contacto, siendo la imagen obtenida de poca calidad y exactitud.Como conclusión de nuestro estudio podemos afirmar que el Método Digital propuesto, era igualmente sensible y exacto que el Método tradicional para la medición de los tamaños mesiodistales de los dientes y para el cálculo de los índices de Bolton, además de para predecir los tamaños en dentición mixta de manera exacta.El método digital era además más rápido que el tradicional con las ventajas de magnificar la imagen de los dientes para su mejor visualización y la posibilidad de almacenar las imágenes en formato digital evitando los problemas del almacenamiento físico de los modelos de escayola.The aims of the Doctoral Thesis were; to introduce and compare a new, fast and accurate Digital Method to measure mesio-distal tooth size, arch length, discrepancy and Bolton index and to predict mesio-distal tooth size for unerupted teeth in mixed dentition. One hundred dental casts of patients were selected, the sample comprised 30 females and 70 males, with a mean decimal age of 14.8 years (range 11.2 -22.7 years). The mesiodistal sizes of the upper and lower teeth of each cast were measured by both methods as follows:For the Traditional Method special callipers were used to measure the mesiodistal size of the casts. For the Digital Method the casts were scanned and with the aid of the mouse as a user interface, we marked the points of the mesiodistal size of each permanent tooth on the image of the casts. The software designed for this purpose, determines dental sizes in millimeters automatically. From this data, we were able to predict the rest of unerupted tooth sizes.Correlation coefficients were almost 1, which shows that values of both Methods were the same. We prepared linear regression graphics in which we represented and compared "real values" and "predicted ones" for each tooth type for every reference tooth. Our results showed the upper central incisor and lower first molar combination was the best reference teeth.The Digital Method presented in this Thesis made it possible to determine measurements and calculations quickly and accurately once the casts have been digitised.The conclusions of our Thesis were that the Digital Method was as sensible and accurate than the Traditional one for measuring mesiodistal tooth-size, Bolton index and to predicting mesiodistal tooth-size of the unerupted teeth

Long-term analysis of upper incisor crowding. A longitudinal study orthodontically treated patients

Introduction: Although there are numerous studies in the literature on alignment stability in the lower arch, there are few referring to the upper arch. Aims: To assess upper arch stability (irregularity index, widths and length of arch, overjet and overbite) in orthodontically treated patients by comparing late incisor stability with the initial malocclusion and type pf treatment undertaken. Study design: The study models of 51 patients, treated with or without extractions, were analysed at three different points in time: pre-treatment (T1), post-treatment (T2) and post-retention (T3) (average 5 years). The following parameters were measured: irregularity index, arch length, inter-canine and inter-molar widths, overjet and overbite. Results: The results showed that upper incisor crowding relapses, although a net improvement is noted in comparison to the initial state both in cases treated with or without extractions. The arch length also relapses in both cases. The inter-canine and inter-molar widths as well as the overjet and overbite are stable in the long term. The long-term response of maxillary incisor alignment is unpredictable. Conclusions: There is a statistically significant reduction in incisor irregularity, length and width of arch (inter-canine and inter-molar widths), whereas overjet and overbite undergo a reduction of little magnitude. No statistically significant correlation is noted between late incisor stability and the initial malocclusion or type of treatment

Digital diagnosis records in orthodontics : An overview

Actualmente la tecnología digital es una realidad que cada vez se impone más en todos los ámbitos clínicos y, por tanto, existe una incorporación también de los ortodoncistas a la digitalización de los registros ortodóncicos diagnósticos. En este trabajo queremos hacer una valoración sobre las ventajas y desventajas, del uso de la radiografía digital, la fotografía digital así como de la última incorporación, los modelos de estudio digitalizados. Basados en encuestas previas, mostraremos la situación actual en nuestro país en cuanto al número de profesionales que utilizan estos registros digitales de manera sistemática

Antibacterial Properties of Nanoparticles in Dental Restorative Materials. A Systematic Review and Meta-Analysis

Background and Objectives: Nanotechnology has become a significant area of research focused mainly on increasing the antibacterial and mechanical properties of dental materials. The aim of the present systematic review and meta-analysis was to examine and quantitatively analyze the current evidence for the addition of different nanoparticles into dental restorative materials, to determine whether their incorporation increases the antibacterial/antimicrobial properties of the materials. Materials and Methods: A literature search was performed in the Pubmed, Scopus, and Embase databases, up to December 2018, following PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines for systematic reviews and meta-analyses. Results: A total of 624 papers were identified in the initial search. After screening the texts and applying inclusion criteria, only 11 of these were selected for quantitative analysis. The incorporation of nanoparticles led to a significant increase (p-value < 0.01) in the antibacterial capacity of all the dental materials synthesized in comparison with control materials. Conclusions: The incorporation of nanoparticles into dental restorative materials was a favorable option; the antibacterial activity of nanoparticle-modified dental materials was significantly higher compared with the original unmodified materials, TiO2 nanoparticles providing the greatest benefits. However, the high heterogeneity among the articles reviewed points to the need for further research and the application of standardized research protocols

A Comparative Study of the Validity and Reproducibility of Mesiodistal Tooth Size and Dental Arch with iTeroTM Intraoral Scanner and the Traditional Method

Introduction: The introduction of intraoral scanning offers an alternative for measuring mesiodistal tooth sizes

A new 3D method for measuring cranio-facial relationships with cone beam computed tomography (CBCT)

Objectives: CBCT systems, with their high precision 3D reconstructions, 1:1 images and accuracy in locating cephalometric landmarks, allows us to evaluate measurements from craniofacial structures, so enabling us to replace the anthropometric methods or bidimensional methods used until now. The aims are to analyse cranio-facial relationships in a sample of patients who had previously undergone a CBCT and create a new 3D cephalometric method for assessing and measuring patients. Study Design: 90 patients who had a CBCT (i-Cat®) as a diagnostic register were selected. 12 cephalometric landmarks on the three spatial planes (X,Y,Z) were defined and 21 linear measurements were established. Using these measurements, 7 triangles were described and analysed. With the sides of the triangles: (CdR-Me-CdL); (FzR-Me-FzL); (GoR-N-GoL); and the Gl-Me distance, the ratios between them were analysed. In addition, 4 triangles in the mandible were measured (body: GoR-DB-Me and GoL-DB-Me and ramus: KrR-CdR-GoR and KrL-CdL-GoL). Results: When analyzing the sides of the CdR-Me-CdL triangle, it was found that the 69.33% of the patients could be considered symmetric. Regarding the ratios between the sides of the following triangles: CdR-Me-CdL, FzR-Me-FzL, GoR-N-GoL and the Gl-Me distance, it was found that almost all ratios were close to 1:1 except between the CdR-CdL side with respect the rest of the sides. With regard to the ratios of the 4 triangles of the mandible, it was found that the most symmetrical relationships were those corresponding to the sides of the body of the mandible and the most asymmetrical ones were those corresponding to the base of such triangles. Conclusions: A new method for assessing cranio-facial relationshps using CBCT has been established. It could be used for diverse purposes including diagnosis and treatment planning

Dental arch changes from adolescence to adulthood in a spanish population : a cross-sectional study

Objectives: Given the controversy in the literature about the variations in intercanine and intermolar distances and arch perimeter once the eruption of permanent teeth is completed, the aims of this study were to assess the changes of these measures with age, analyzing its sexual dimorphism and variability in a Spanish population. Study Design: 188 Spanish individuals distributed in three age groups were selected: 63 adolescents (mean age: 14.15 years), 62 young adults (mean age: 21.9 years) and 63 adults (mean age: 40 years). The intercanine and intermolar distances and arch perimeter were measured in each dental cast from each individual of the sample using a digital method. The results were compared between sex and age groups, the sexual dimorphism percentage (%) of each measure and its variability coefficient (VC%) were calculated. Results: The results depend on sex and age and, therefore, these two factors will be analyzed jointly for each of them with the variation coefficient of the measurement. Intercanine and intermolar distances and arch perimeter were greater in men than in women, especially in the young adult and adult groups. Conclusions: The intercanine distance and arch perimeter tended to decrease with age particularly in the female sex, whilst the intermolar distance didn't undergo significant changes. The intercanine distance is the dimension that presented the greatest variability, whereas the intermolar distance presented the least. The changes occur in the transition from adolescence (14 years of age) to adulthood (22 years of age) and the subsequent alterations are not relevant. © Medicina Oral S. L

Tooth size changes with age in a Spanish population : percentile tables

Objectives: The aims of this work were: firstly, to draw up tables of percentile tooth sizes similar to those of Sanin and Savara for three age groups of a Spanish population; secondly, to describe changes in tooth size between those groups over time, as well as observing any sexual dimorphism and, finally, to compare both the Spanish and Sanin and Savara's American population samples. Material and methods: The sample included 359 patients and was divided into three age groups: adolescents, young adults and adults, of both genders. After dental cast digitalization, mesiodistal tooth-size was measured on each dental cast using a digital method. Dental size tables organized by percentiles for each group of age and gender were drawn up. Percentiles under 30 were considered as small, between 30 and 70 as average, and above 70 as large. As symmetry was found between contralateral teeth, the mean between the teeth of the two semi-arches was considered. Results: The mesiodistal tooth sizes of adolescents did not present statistically significant differences between genders, in contrast to the two other age groups. Conclusions: Mesiodistal tooth diameters tended to diminish with age, especially in women, in the Spanish population. The values obtained for our dental tables, organized by percentiles, were slightly higher than those found by Sanin and Savara in an American population, especially for women. © Medicina Oral S. L

Study between anb angle and wits appraisal in cone beam computed tomography (cbct)

Objectives: To analyse the ANB and Wits values and to study correlations between those two measurements and other measurements in diagnosing the anteroposterior maxilo-mandibular relationship with CBCT. Study Design: Ninety patients who had previously a CBCT (i-CAT ® ) as a diagnostic register were selected. A 3D cephalometry was designed using one software package, InVivo5 ® . This cephalometry included 3 planes of reference, 3 angle measurements and 1 linear measurement. The means and standard deviations of the mean of each measurement were assessed. After that, a Pearson's correlation coefficient has been performed to analyse the significance of each relationship. Results: When classifying the sample according to the anteroposterior relationship, the values obtained of ANB (Class I: 53%; Class II: 37%; Class III: 10%) and Wits (Class I: 35%; Class II: 56%; Class III: 9%) did not coincide, except for the Class III group. However, of the patients classified differently (Class I and Class II patients) by ANB and Wits, a high percentage of individuals (n=22; 49%), had a mesofacial pattern with a mandibular plane angle within normal values. A correlation has been found between ANB and Wits (r=0,262), occlusal plane angle and ANB (r=0,426), and mandibular plane angle and Wits (r=0,242). No correlation was found between either Wits or ANB in relation with the age of the individuals. Conclusions: ANB and Wits must be included in 3D cephalometric analyses as both are necessary to undertake a more accurate diagnosis of the maxillo-mandibular relationship of the patients