Cephalometric measurements from 3D reconstructed images compared with conventional 2D images

Abstract Objective: To assess whether the values of different measurements taken on three-dimensional (3D) reconstructions from cone-beam computed tomography (CBCT) are comparable with those taken on two-dimensional (2D) images from conventional lateral cephalometric radiographs (LCRs) and to examine if there are differences between the different types of CBCT software when taking those measurements. Material and Methods: Eight patients were selected who had both an LRC and a CBCT. The 3D reconstructions of each patient in the CBCT were evaluated using two different software packages, NemoCeph 3D and InVivo5. An observer took 10 angular and 3 linear measurements on each of the three types o…

Influence of skeletal class in the morphology of cervical vertebrae: A study using cone beam computed tomography

ABSTRACT Objectives: To quantify the prevalence of cervical vertebrae anomalies and to analyze any association between them and skeletal malocclusions or head posture positions in the same study. Materials and Methods: Two hundred forty patients who were attending the Department of Orthodontics of the University of Valencia for orthodontic treatment were selected and divided into three groups: skeletal Class I (control group, 0° <ANB < 4°), Class II (ANB ≥ 4°), and Class III (ANB ≤ 0°) according to ANB Steiner angle. The morphology of the first five cervical vertebrae was analyzed with cone beam computed tomography to identify any anomalies. Intra- and interobserver error meth…

Prediction of arch length based on intercanine width.

Arch length (AL), intercanine width (ICW), and intermolar width (IMW) are essential for diagnosis and treatment planning and are closely related factors in orthodontics. The aim of the present study was to determine correlations between these measurements and to predict some of these measurements based on others. The dental casts of 197 Spanish patients (119 females and 78 males) with a mean age of 18 years (11-26 years) in the permanent dentition attending the Orthodontic Department of the University of Valencia, Spain, were selected. ICW, IMW, and AL on each dental cast were measured using a previously tested digital method. Correlation between variables was determined using Pearson's cor…

Análise da discrepância ósseo-dentária desde a adolescência até à quinta década de vida: estudo transversal

Resumo Objectivos Descrever e avaliar as alteracoes da discrepância osseo-dentaria (DOD) com a idade em ambos sexos. Material e metodos Seleccionaram-se 188 individuos da cidade de Valencia, Espanha, distribuidos por tres grupos de idade: 63 adolescentes (idade media: 14,15 anos), 62 jovens (idade media: 21,9 anos) e 63 adultos (idade media: 40 anos). O diâmetro mesiodistal de cada dente e o perimetro de arcada foram medidos em cada um dos modelos de estudo obtidos de cada individuo da amostra usando um metodo digital e foi calculada a DOD (positiva e negativa) para cada arcada. Compararam-se os resultados obtidos entre sexos e grupos de idade. Resultados Os resultados variaram em cada arca…

Use of self-organizing maps for analyzing the behavior of canines displaced towards midline under interceptive treatment

Background Displaced maxillary permanent canine is one of the more frequent findings in canine eruption process and it’s easy to be outlined and early diagnosed by means of x-ray images. Late diagnosis frequently needs surgery to rescue the impacted permanent canine. In many cases, interceptive treatment to redirect canine eruption is needed. However, some patients treated by interceptive means end up requiring fenestration to orthodontically guide the canine to its normal occlusal position. It would be interesting, therefore, to discover the dental characteristics of patients who will need additional surgical treatment to interceptive treatment. Material and Methods To study the dental cha…

Influence of first and second premolar extraction or non-extraction treatments on mandibular third molar angulation and position. A comparative study.

The mandibular third molar (3M) is the tooth that is most often impacted, with lack of space being one of the reasons. In some orthodontic treatments, premolars are extracted in order to create space. The aims of our study are: firstly, to assess the changes in the angulation and position of the 3M in cases treated either with or without extraction of the first or second premolars; secondly, to analyse the variation in the gonial angle and the degree of inclusion of the 3M; and lastly, to establish a predictive impaction model for 3M. This study included 88 patients: 28 patients treated with extractions of first premolars, 30 with second premolars and 30 without. The initial and final ortho…

Determination of Bolton tooth-size ratios by digitization, and comparison with the traditional method.

The Bolton Index is one of the most useful calculations for precise orthodontic diagnosis as it shows if there is a correct ratio between dental proportions. However, at times, this calculation is not applied because it is a long and time-consuming procedure compared with digital methods. A new digital method for measuring tooth sizes and for calculating the Anterior (ABI) and the Overall (OBI) Bolton Index was tested on 100 sets of study dental casts of the permanent dentition in a Spanish sample and compared with the traditional method. The reproducibility of this digital method versus the traditional one was analysed to determine intra- and inter-examiner measurement errors by calculatin…

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 t…

A study on the reproducibility of cephalometric landmarks when undertaking a three-dimensional (3D) cephalometric analysis

Objectives: Cone Beam Computerized Tomography (CBCT) allows the possibility of modifying some of the diagnostic tools used in orthodontics, such as cephalometry. The first step must be to study the characteristics of these devices in terms of accuracy and reliability of the most commonly used landmarks. The aims were 1- To assess intra and inter-observer reliability in the location of anatomical landmarks belonging to hard tissues of the skull in images taken with a CBCT device, 2- To determine which of those landmarks are more vs. less reliable and 3- To introduce planes of reference so as to create cephalometric analyses appropriated to the 3D reality. Study design: Fifteen patients who h…

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…

A comparative study of the pharyngeal airway space, measured with cone beam computed tomography, between patients with different craniofacial morphologies.

Abstract Purpose The present study aims to determine any existing association between airway dimensions, measured with cone beam computed tomography (CBCT), and the different patient craniofacial morphologies. Material and methods Sixty CBCT (Dental Picasso Master 3D) images, from patients treated at the Orthodontics Master at Valencia University were selected. The program InVivoDental 5.1 was used to visualize sections, analyze three-dimensional images, and perform airway measurements in the three planes of the space. Intra- and interobserver error methods were recorded. After that, measurements at three different levels of the airway (upper, medium, lower) were taken, in both the anteropo…

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 …

New regression equations for predicting human teeth sizes

Introduction The aims of the study were; to evaluate the applicability of the Moyers and Tanaka-Johnston Methods to individuals with a Spanish ancestry, to propose new regression equations using the lower four permanents incisors as predictors for the sum of the widths of the lower permanent canine and premolars, and to compare the new data to those from other populations. Methods A total of 359 Spanish ancestry adolescents were selected. Their dental casts were measured using a 2D computerized system. Real teeth measurements were compared with those predicted using Moyers probability tables and Tanaka and Johnston equations, and standard regression equations were then developed. Results Re…

Long-term stability of surgical-orthodontic correction of class III malocclusions with long-face syndrome

Objectives: In the first place, to evaluate skeletal changes of the maxilla and mandible induced by surgical-orthodontic correction of malocclusions class III with long-face syndrome and secondly, to analyze the stability of these skeletal changes in the long term (more than 6 years). Design of Study: A retrospective, unicentric and longitudinal study of 19 patients who had undergone surgical and orthodontic therapy for class III skeletal malocclusion with long-face syndrome was undertaken. A cephalometric analysis based on 8 angle measurements, and statistical analyses at three different points in time (before orthodontic treatment, after orthognathic surgery and after a retention period o…

Smile esthetics from odontology students' perspectives

ABSTRACT Objectives: To analyze the perception of smile esthetics and its alterations in dental degree students; to determine whether there are differences in that perception among students in different study years on those courses and between genders; and to determine if the circumstance of having received prior orthodontic treatment could influence that perception. Material and Methods: Students (n = 192) in different study years of the dental degree course at the University of Valencia, Spain, analyzed two photographs of a patient in which, by means of computer software, midline diastema, upper and lower midlines, crown length of the maxillary right central incisor, occlusal cant, and “g…

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 a…

A comparison between dental measurements taken from CBCT models and those taken from a digital method.

The aims of the study were to assess speed, reliability, accuracy, and reproducibility in measuring mesiodistal tooth sizes, bicanine widths, bimolar widths, and arch lengths (ALs) using cone beam computed tomography (CBCT) and to compare them with the same measurements obtained using a two-dimensional (2D) Digital Method. Plaster study models were made for 27 patients and then digitalized and measured using a 2D Digital Method. CBCTs were undertaken on the same 27 patients using the Dental Picasso Master 3D® and the images obtained were then analysed using the InVivoDental program. The correlation study of the two measuring methods, which were compared by determining the regression paramet…

Do Bolton’s ratios apply to a Spanish population?

Introduction: Previous studies have shown that populations differ with respect to interarch tooth-size relationships, and differences in tooth sizes are not systematic. The aims of this study were to determine the Bolton ratios in Spanish subjects. Methods: We used a digital method and measured the casts to the nearest 0.05 mm. The sample consisted of 100 pairs of dental casts of Spanish subjects. The Kolmogorov-Smirnov test, t test, and 95% confidence intervals were used. Results: Anterior tooth-width ratios were 78.31% ± 2.59% for women and 78.34% ± 2.16% for men (P = .955). Total tooth-width ratios were 91.91% ± 2.04% for women and 92.10% ± 1.73% for men (P = .668). No significant differ…

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…

Effects of endodontic treatment on apparent Young’s modulus of human teeth: in vitro study using speckle interferometry

The introduction of new techniques for endodontic procedures requires the analysis of the biomechanical behavior of dental structures. Digital speckle shearing pattern interferometry (DSSPI) is a nondestructive optical measuring technique that allows one to directly quantify deformations in teeth that are subjected to stress. DSSPI technique was applied to measure small deformations caused by flexion in different types of teeth. The test was carried out both before and after endodontic treatment with the ProTaper method in order to evaluate the variation of dental elasticity, taking into the account the type of tooth and the endodontic treatment. The results obtained show that dental elasti…

Traumatismos dentarios en la infancia

Evaluation of the validity of the Bolton Index using cone-beam computed tomography (CBCT)

Aims: To evaluate the reliability and reproducibility of calculating the Bolton Index using cone-beam computed tomography (CBCT), and to compare this with measurements obtained using the 2D Digital Method. Material and Methods: Traditional study models were obtained from 50 patients, which were then digitized in order to be able to measure them using the Digital Method. Likewise, CBCTs of those same patients were undertaken using the Dental Picasso Master 3D® and the images obtained were then analysed using the InVivoDental programme. Results: By determining the regression lines for both measurement methods, as well as the difference between both of their values, the two methods are shown t…

New, fast, and accurate procedure to calibrate a 2-dimensional digital measurement method.

Traditionally, dental casts have been measured by hand, with conventional calipers. Today, several digital methods are available for automatically measuring tooth size, but their accuracy depends on proper calibration. The purpose of this article is to introduce a fast and accurate procedure to calibrate a previously introduced 2-dimensional computerized system of measuring mesiodistal tooth size and calculating overall and anterior Bolton ratios. In this calibration method, the cast is digitized while sitting on a sheet of graph paper. The magnification of the paper in 2 axes can be easily calculated and hence the magnification of the dental cast digital image.