Jose Luis Gandia

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 parameters and the values of one method as opposed to the other, show how both methods are comparable, although the mean and standard deviation of all the measurements analysed present statistically significant differences for the first upper right premolar, first upper left molar, first lower left premolar, and second lower right premolar, as well for the lower intercanine distance and lower AL. The differences, however, are less than 1 per cent. CBCT digital models are as accurate and reliable as the digital models obtained from plaster casts. The differences existing between both methods are clinically acceptable.

Orthodontic treatment need in Spanish schoolchildren: an epidemiological study using the Index of Orthodontic Treatment Need

The aim of this study was to determine the prevalence of malocclusion and orthodontic treatment need in 12- to 16-year-old Spanish schoolchildren using the aesthetic component (AC) and Dental Health Component (DHC) of the Index of Orthodontic Treatment Need (IOTN) and to analyse the relationship with gender and age. The study followed the World Health Organization recommendations for oral health surveys. The sample comprised 655 schoolchildren (306 males and 349 females) who had not undergone orthodontic treatment, divided into two groups: 363 12-year-olds and 292 15- to 16-year-olds, out of a representative sample of the school population of the Valencian Community. The IOTN results were analysed with regard to gender using the chi-square test. Orthodontic treatment need, using the DHC, was found in 21.8 per cent of the 12-year-olds and in 17.1 per cent of the 15- to 16-year-olds; and with the AC in 4.4 and 2.4 per cent, respectively. Considering both components together, 23.5 per cent of the population [confidence interval (CI) 95%: 19.2-28.1] of 12-year-olds and 18.5 per cent (CI 95% 14.2-23.4) of 15- to 16-year-olds had a definite treatment need. No gender dependent differences were found. Spanish orthodontic treatment need is similar to that reported in most recent studies in Europe, with approximately one in five to six children with an orthodontic treatment need.

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

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 of record on two different occasions. RESULTS Intraobserver reliability was high except for the mandibular plane and facial cone (from the LCR), the Na-Ans distance (using NemoCeph 3D), and facial cone and the Ans-Me distance (using InVivo5). No statistically significant differences were found for the angular and linear measurements between the LCRs and the CBCTs for any measurement, and the correlation levels were high for all measurements. CONCLUSION No statistically significant differences were found between the angular and linear measurements taken with the LCR and those taken with the CBCT. Neither were there any statistically significant differences between the angular or linear measurements using the two CBCT software packages.

Diagnostic agreement in the assessment of orthodontic treatment need using the Dental Aesthetic Index and the Index of Orthodontic Treatment Need

The aim of this study was to estimate the diagnostic agreement between assessments of orthodontic treatment need of a child population using the Dental Aesthetic Index (DAI) and the Index of Orthodontic Treatment Need (IOTN). A cross-sectional study of a representative random sample of children aged 12 (n = 475) and 15-16 (n = 398) years was carried out in the Valencia region of Spain. A Students t-test was used to compare the DAI means by gender and age and a chi-square test to compare the proportions of the population in need of orthodontic treatment. To calculate the agreement between the two indices, intra-class correlation coefficient and Kappa statistics were employed. Of the 12-year-olds, 23.5 percent (n = 121) and of the 15- to 16-year-olds, 26.6 percent (n = 108) were receiving or had previously received orthodontic treatment. The observed agreement between the two indices on the need for treatment among the 12-year-olds (n = 363) was 83.4 percent and Kappa for diagnostic agreement was 0.52 [95 percent confidence interval (CI): 0.42-0.63]. For the 15- to 16-year-olds (n = 292), the figures were 82.5 percent and 0.38 (95 percent CI: 0.24-0.52), respectively. For the total sample (n = 655), the observed agreement was 83 percent and the diagnostic agreement was 0.47 (95 percent CI: 0.39-0.55). For this population, there was only moderate agreement between the two indices. This means that, when one of these indices is used to measure or prioritize orthodontic treatment in a determined population, the individuals selected with an obvious treatment need are going to be different in 17 percent of the cases depending on which index is used, DAI or IOTN. This difference has to be taken in consideration when measuring, recording, or quantifying orthodontic treatment need.

A New, Accurate and Fast Digital Method to Predict Unerupted Tooth Size

The sum of the lower incisor tooth width has been proposed as the best predictor for calculating unerupted canine and premolar mesiodistal tooth sizes. The aims of this study were to develop a new, fast, and accurate computerized method to predict unerupted mesiodistal tooth sizes and to determine which reference tooth or combination of reference teeth was the best predictor for canines and premolars in a Spanish sample. The dental casts of 100 Spanish adolescents with permanent dentition were measured to the nearest 0.05 mm with a two-dimensional computerized system. The goal was to predict unerupted canine and premolar mesiodistal tooth sizes using the sizes of the upper central incisor, upper and lower first molar, or a combination of these as a reference and using a specific mesiodistal tooth-size table. The results showed that the Digital Method proposed was very accurate in predicting unerupted canine and premolar tooth size. The combination of the sums of the permanent upper central incisor and the lower first molar was the best predictor for canines and premolars in this sample. Upper arch teeth were better predicted than lower arch teeth. The upper lateral incisor provided the worst predictions.

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 Pearsons correlation coefficient. Linear regression analysis was applied and the 95 per cent confidence intervals (CIs) for slope and intercept were determined. The data showed very high correlations between ICW and AL, both for the upper and lower arches and for males and females, r = 0.925. This coefficient was very close to 1, indicating a linear relationship. The regression equation for AL and ICW was AL = 1.36 ICW + 29.39 for both arches. There was very high correlations between AL and ICW for the upper and lower arches and a regression equation between both magnitudes was established indicating that the size of one factor can be predicted by knowing the other. For an increase of 1 mm in ICW, the AL increases approximately 1.36 mm with a 95 per cent CI (1.30-1.42).

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

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 anteroposterior and transversal directions of the airway space. The area (mm(2)) of the airway space at the three levels was also measured. RESULTS In the anteroposterior airway measurements, there were differences between the measurements by level. The magnitude of these differences depended on the skeletal pattern of the individual. In the transversal airway measurements and in the area airway measurements, there were no differences according to the skeletal pattern. However, in the transversal direction, measurements in the lower level were significantly higher than in the superior level in all cases. When measuring the area, significantly higher measurements in the upper level were recorded. The homogeneity between medium and lower levels decreased gradually from class I to class III subjects. CONCLUSIONS No statistically significant results were observed that related the anteroposterior and vertical skeletal craniofacial morphology with airway dimensions, although some specific associations have been detected for certain airway levels or for pattern combinations.

Comparative study of reproducibility and accuracy in measuring mesiodistal tooth sizes using three different methods: 2D digital, 3D CBCT, and 3D CBCT segmented

ObjectivesTo develop a 3D cone-beam computed tomography (CBCT) method (CBCT method) for determining tooth sizes and arch dimensions and to compare the accuracy and reproducibility of that method with those of a previously described 3D segmented CBCT method (CBCT seg. method) and a 2D digital method.MethodsPlaster study models and CBCT images were available for 34 patients. For the first method, the plaster study casts were digitalized and measured using the 2D digital method. For the second method, CBCT seg. method, the CBCT images were sent in DICOM format to InVivoDental® Company for segmentation and conversion into three-dimensional images of the models. For the third method, CBCT method, axial cuts were performed on the CBCT images, and tooth sizes and arch dimensions were measured using Anatomage® software.ResultsSignificant differences were found between the tooth size measurements obtained with the 3D CBCT method and the 2D digital method, but not for the intercanine width, intermolar width, and arch length. There were no significant differences between the measurements obtained with the CBCT seg. method and the 2D digital method.ConclusionsA 3D CBCT method has been developed. It presented good accuracy for the intercanine width, intermolar width, and arch length, but not for the mesiodistal tooth sizes. Model segmentation will be necessary for measurements of tooth size.

Orthodontic camouflage versus orthognathic surgery for class III deformity: comparative cephalometric analysis.

The objective of this study was to compare different cephalometric variables in adult patients with class III malocclusions before and after treatment, in order to determine which variables are indicative of orthodontic camouflage or orthognathic surgery. The cases of 156 adult patients were assessed: 77 treated with orthodontic camouflage and 79 treated with orthodontics and orthognathic surgery. The following cephalometric variables were measured on pre-treatment (T1) and post-treatment (T2) lateral cephalograms: sella-nasion-A-point (SNA), sella-nasion-B-point (SNB), and A-point-nasion-B-point (ANB) angles, Wits appraisal, facial axis angle, mandibular plane angle, upper and lower incisor inclination, and inter-incisal angle. There were statistically significant differences in cephalometric variables before and after treatment between the two groups. The percentage of normal pre-treatment measurements in the camouflage orthodontics group was 30.7%, which worsened slightly to 28.4% post-treatment. However in the group receiving surgery, this was 24.5% pre-treatment, improving to 33.5% after surgery. SNA, SNB, Wits appraisal, lower incisor inclination, and inter-incisal angle showed differences between the two groups before and after treatment. Wits appraisal, lower incisor inclination, and inter-incisal angle were indicative of one or other treatment. Upper and lower incisor decompensation in both groups did not reach ideal values, which impeded complete skeletal correction in 52% of surgical cases.

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

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 methods were calculated. RESULTS Dehiscence and fusion of one unit (both 23.3%) and partial cleft (11.7%) were the most frequent anomalies, while occipitalization was the least common (3.3%). Dehiscence anomaly was observed when the control group was compared with Classes II and III and partial cleft anomaly when Class I was compared with Class III. Furthermore, NSBa and ss-N-sm/ANB angles were associated with partial cleft anomaly, while NSL/NL angle and extended head posture were associated with fusion anomaly. CONCLUSIONS Fusion, dehiscence, and partial cleft were the most frequent cervical vertebrae anomalies. Dehiscence and partial cleft were found to present statistically significant differences between Class I and Classes II and III. Cervical vertebrae anomalies and head posture were associated with fusion.