Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 425
Filtrar
1.
Am J Orthod Dentofacial Orthop ; 156(6): 870-877, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31784021

RESUMEN

INTRODUCTION: This study aimed to evaluate the ability of dental clinicians to predict posttreatment dental arch forms in patients with malocclusion with the aid of 3D imaging and digital software in comparison with a conventional method. METHODS: Pretreatment and posttreatment dental plaster casts of 100 patients (200 maxillary models and 200 mandibular models) were selected. Three orthodontists selected the best-fitted archwires among 5 commercially available preformed nickel-titanium archwires using 2 methods. In the conventional method, they fit the archwires to pretreatment casts, and in the digital method, they fit the scanned wire to a 3D digital model, using Ortho-Aid, a locally developed 3D software, using clinical bracket points as reference for wire fitness. The predicted posttreatment archwire in each method was compared with the best-fit archwire on the actual posttreatment model of each patient in both methods, and the level of agreement was calculated. The interobserver agreement between the 3 orthodontists in each method was evaluated using intraclass correlation coefficient and the Dahlberg formula. RESULTS: Orthodontists predicted the final treatment outcome in 50% of cases using the conventional method and 58% using the digital method. However, the range of method error was significantly higher in the conventional method (0.425-3.853 mm for the conventional vs 0.451-0.584 mm for the digital). CONCLUSIONS: Although the clinicians' ability to predict the final dental arch form after orthodontic treatment and the agreement between clinicians increased by the use of digital equipment, orthodontists can predict the final arch form in about 60% of patients.


Asunto(s)
Arco Dental , Imagenología Tridimensional , Alambres para Ortodoncia , Ortodoncia Correctiva , Aleaciones Dentales , Arco Dental/anatomía & histología , Arco Dental/diagnóstico por imagen , Modelos Dentales , Predicción , Humanos , Mandíbula , Programas Informáticos
2.
PLoS One ; 14(11): e0222070, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31743331

RESUMEN

The aim of this study was to evaluate the trueness of 5 intraoral scanners (IOSs) for digital impression of simulated implant scan bodies in a partially edentulous model. A 3D printed partially edentulous mandible model made of Co-Cr with a total of 6 bilaterally positioned cylinders in the canine, second premolar, and second molar area served as the study model. Digital scans of the model were made with a reference scanner (steroSCAN neo) and 5 IOSs (CEREC Omnicam, CS3600, i500, iTero Element, and TRIOS 3) (n = 10). For each IOS's dataset, the XYZ coordinates of the cylinders were obtained from the reference point and the deviations from the reference scanner were calculated using a 3D reverse engineering program (Rapidform). The trueness values were analyzed by Kruskal-Wallis test and Mann-Whitney post hoc test. Direction and amount of deviation differed among cylinder position and among IOSs. Regardless of the IOS type, the cylinders positioned on the left second molar, nearest to the scanning start point, showed the smallest deviation. The deviation generally increased further away from scanning start point towards the right second molar. TRIOS 3 and i500 outperformed the other IOSs for partially edentulous digital impression. The accuracy of the CEREC Omnicam, CS3600, and iTero Element were similar on the left side, but they showed more deviations on the right side of the arch when compared to the other IOSs. The accuracy of IOS is still an area that needs to be improved.


Asunto(s)
Implantes Dentales , Técnica de Impresión Dental , Diagnóstico por Imagen , Diente Premolar , Diente Canino , Arco Dental/diagnóstico por imagen , Modelos Dentales , Diagnóstico por Imagen/métodos , Humanos , Imagenología Tridimensional , Diente Molar , Boca Edéntula/diagnóstico por imagen , Boca Edéntula/terapia
3.
Niger J Clin Pract ; 22(10): 1448-1456, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31607738

RESUMEN

Objective: The purpose of this study was to investigate a relationship between gingival tissue biotypes and arch form with Schneiderian membrane thickness, using limited cone beam computed tomography. Materials and Methods: A total of 90 subjects were selected. For each subject three parameters were assessed - gingival biotype - clinically by Probe transparency method as thin or thick and coded as 0 and 1, respectively, gingival thickness and Schneiderian membrane thickness in mm, arch form as square, oval, or tapered (radiographically by cone beam computed tomography images). Central incisors and first molars were assessed for gingival biotype and gingival thickness and Schneiderian membrane thickness was determined at 16. Numerical data were estimated for normal distribution. Analysis of Variance test was followed by Tukey honestly significant difference test and Pearson's correlation coefficient test for analysis. Results: Thin gingival biotype was found associated with the central incisors and thick gingival biotype with molars. Limited cone beam computed tomography scans evaluation revealed highest prevalence of square arch form followed by oval, and tapered. The average thickness of the Schneiderian membrane was 1.18 ± 0.43 mm on left side and 1.09 ± 0.41 mm on right side with a range of 0.50 - 2.00 mm. Mean Schneiderian membrane thickness was more in case of thick gingival biotype and with square arc form both on right and left sides. Conclusions: The Schneiderian membrane thickness was positively and highly associated with gingival biotype. The gingival biotype and arch form had significant effect on Schneiderian membrane thickness and can provide valuable clinical information on Schneiderian membrane thickness preoperatively for implant placement and sinus lift procedures.


Asunto(s)
Tomografía Computarizada de Haz Cónico/métodos , Implantes Dentales , Encía/diagnóstico por imagen , Mucosa Nasal/diagnóstico por imagen , Arco Dental/anatomía & histología , Arco Dental/diagnóstico por imagen , Femenino , Encía/anatomía & histología , Humanos , Masculino , Diente Molar , Adulto Joven
4.
Eur. j. anat ; 23(4): 273-277, jul. 2019. graf, tab
Artículo en Inglés | IBECS | ID: ibc-183001

RESUMEN

A thorough knowledge of external dental root morphology is fundamental for having successful endodontic, orthodontic and surgical treatments in dentistry. The aim of this anatomical study was to determine the incidence of tooth dilacerations in Kerman, a province in the Southeastern Islamic Republic of Iran. A cross-sectional study was performed on a total of 3150 teeth from 800 PA radiographs; 100 radiographs from each 8 anatomic divisions of the dental arch, within a Kerman population. The numbers of radiographs were equal between 2 genders; 400 from females and 400 from males. Radiographs were studied by 3 specialists in this field in order to determine and record the prevalence and distribution of dilacerations in different teeth of this population. Amongst the total of 3150 teeth from 800 radiographs, 52 teeth (1.65%) showed dilacerations. The prevalence of this anomaly was 7.5% in males and 5% in females, and the distribution was almost equal between different teeth of the maxilla (2%-4%); meanwhile in the mandible, the maximum prevalence was in third molars (14%) and the rate was nil in anterior teeth (Spss and Excel softwares, IBM). The prevalence of tooth dilacerations was almost equal between genders in the Kerman population that was studied. The findings indicated that the presence of dilacerated roots was more prevalent in females in the mandibular arch, while this anomaly was more prevalent in males in the maxillary arch. Interestingly, none of the mandibular incisor teeth displayed this anomaly


No disponible


Asunto(s)
Humanos , Masculino , Femenino , Dentición Permanente , Arco Dental/anatomía & histología , Arco Dental/anomalías , Mandíbula/anatomía & histología , Maxilar/anomalías , Irán , Arco Dental/diagnóstico por imagen
5.
Comput Methods Programs Biomed ; 175: 205-214, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31104708

RESUMEN

BACKGROUND AND OBJECTIVE: Panoramic images reconstructed from dental cone beam CT (CBCT) data have been effectively used in dental clinics for disease diagnosis. Panoramic images generally have low contrast because excessive non-interest tissues participate in the reconstruction, which may affect the diagnosis. In this study, we developed a fully automatic reconstruction method to improve the global and detail contrast of panoramic images. METHODS: The proposed method consists of dental arch thickness detection, image synthesis, and image enhancement. First, the dental arch thickness is detected from an axial maximum intensity projection (MIP) image generated from the axial slices containing the teeth to reduce non-interest tissues in panoramic image reconstruction. Then, a new synthesis algorithm is proposed at image synthesis stage to reduce the effect of non-interest tissues on image contrast. Finally, an image enhancement algorithm is applied to the synthesized image to improve the detail contrast of the final panoramic image. RESULTS: A total of 129 real clinical dental CBCT data sets were used to test the proposed method. The panoramic images generated by three methods were subjectively scored by three experienced dentists who were blinded to the generated method. The evaluation of image contrast included the maxillary, mandible, teeth, and particular region (root canal, crown reconstruction, implants, and metal brackets). The overall image contrast score revealed that the proposed method scored the highest of 11.03 ±â€¯2.46, followed by the ray sum and x-ray methods with corresponding scores of 6.4 ±â€¯1.65 and 5.35 ±â€¯1.56. The results of expert subjective scoring indicated that the image contrast of the panoramic image generated by the proposed method is higher than those of existing methods. CONCLUSIONS: The proposed method provides a quick, effective and robust solution to improve the global and detail contrast of the panoramic image generated from dental CBCT data.


Asunto(s)
Tomografía Computarizada de Haz Cónico , Arco Dental/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador/métodos , Radiografía Dental , Radiografía Panorámica , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Algoritmos , Niño , Femenino , Humanos , Masculino , Mandíbula/diagnóstico por imagen , Maxilar/diagnóstico por imagen , Persona de Mediana Edad , Reconocimiento de Normas Patrones Automatizadas , Reproducibilidad de los Resultados , Diente/diagnóstico por imagen , Adulto Joven
6.
BMC Oral Health ; 19(1): 66, 2019 04 27.
Artículo en Inglés | MEDLINE | ID: mdl-31029133

RESUMEN

BACKGROUND: Studies focusing on accuracy of intraoral digital models in the palatal region are scarce. The present study aimed to investigate the influence of different scanning sequences on palatal trueness and to assess deviation and distribution character of trueness in palate. METHODS: Overall, 35 participants accepted three types of procedures to acquire upper digital models. Indirect models digitalised from plaster models were considered as the reference. Two direct digital models were acquired using TRIOS 3 POD intraoral scanners, namely Groups Tr1 and Tr2, wherein intraoral scanning differed in terms of palatal scanning sequences. Based on a modified dental-level superimposition method, 3D measurements of trueness in palate and palatal vault region (PVR) for palatal stable regional superimposition in Groups Tr1 and Tr2, respectively, were performed. Absolute deviations were measured for trueness, while signed deviations were analysed for shape distortion. Colour-coded maps were used for quantitative analysis of deviation distribution pattern. Paired t test was used to analyse differences in palatal trueness between different scanning sequences. One-way repeated-measures analysis of variance and Bonferroni test were used to compare trueness measurements among different superimposition methods. Intraclass correlation coefficient (ICC) was used to verify reproducibility of the proposed method. RESULTS: Palatal trueness in Group Tr1 (118.59 ± 37.67 µm) was slightly less accurate than that (108.25 ± 33.83 µm) in Group Tr2 (p = 0.012 < 0.05). Trueness of PVR in Groups Tr1 (127.35 ± 54.11 µm) and Tr2 (118.17 ± 49.52 µm) did not differ significantly (p = 0.149). Moreover, no significant difference was noted in distortion of the palatal region and PVR in Groups Tr1 and Tr2 (p = 0.582 and 0.615, respectively). A similar pattern of palatal trueness was noted in a majority of participants (22/35). For 3D palatal trueness measurement, there were different applications for different superimposition methods. ICC for the proposed method was > 0.90. CONCLUSIONS: Scanning sequences can affect palatal trueness. Palatal scanning should be initiated at the palatal side of the posterior teeth where the initial scan begins. For 3D PVR superimposition, distal boundary of the selected region should be adjusted mesially whilst referring to intraoral digital models. TRIAL REGISTRATION: The trial has been registered (registration No: R000039467 , Trial ID: UMIN000034617, date of registration: 2018/10/24'retrospectively registered').


Asunto(s)
Arco Dental/anatomía & histología , Arco Dental/diagnóstico por imagen , Materiales de Impresión Dental , Técnica de Impresión Dental , Diseño de Prótesis Dental/métodos , Procesamiento de Imagen Asistido por Computador/instrumentación , Paladar (Hueso)/anatomía & histología , Diseño Asistido por Computadora , Modelos Dentales , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Imagenología Tridimensional/métodos , Reproducibilidad de los Resultados , Estudios Retrospectivos
7.
Comput Methods Programs Biomed ; 172: 95-101, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30902131

RESUMEN

BACKGROUND AND OBJECTIVE: The dental arch form is generally used as a base for planning orthodontic treatments. It is, therefore, vital to determine the proper individual dental arch form for more accurate orthodontic treatment. We aimed to develop and validate a robust algorithm for semi-automatic determination of the dental arch form in dental cone-beam CT (CBCT) images with the cubic B-spline approximation. METHODS: Our algorithm consists of tooth segmentation, determination of an occlusal plane, and generation of intersection points between the teeth and the offset plane from the occlusal plane in CBCT images. By fitting a curve to the intersection points using the cubic B-spline curve approximation, the dental arch form was finally determined. The accuracy of the dental arch forms was evaluated by comparison with gold standards determined by an expert orthodontist. RESULTS: Thirteen dental CBCT scans from nine subjects were enrolled in this study. From the CBCT scans, 13 maxillary arch forms and 11 mandibular arch forms with Class I occlusion were determined by our proposed algorithm and evaluated for validation. The mean error between the dental arch forms of gold standards and our method using the cubic B-spline was 0.413 ± 0.092 mm (range, 0.264-0.587 mm). CONCLUSIONS: Our proposed method showed reliable accuracy of determining the dental arch forms for the maxilla and mandible. These results suggested that this method might be used for planning automatic tooth setup for individual patients.


Asunto(s)
Tomografía Computarizada de Haz Cónico/métodos , Arco Dental/diagnóstico por imagen , Arco Dental/fisiología , Algoritmos , Oclusión Dental , Humanos , Imagenología Tridimensional , Mandíbula , Radiografía Panorámica
8.
Radiologia ; 61(3): 225-233, 2019.
Artículo en Inglés, Español | MEDLINE | ID: mdl-30827491

RESUMEN

BACKGROUND AND OBJECTIVE: There is a lack of quantitative measures of the quality of alveolar trabecular bone, an important factor in implantology. This study aimed to develop a method of objectively assessing the quality of trabecular bone by means of image processing and structural analysis of multidetector computed tomography images and to establish differences between tooth types and tooth presence/absence. MATERIALS AND METHODS: We analyzed 20 patients who underwent multidetector computed tomography to evaluate mandibular bone and tooth positioning. Image analysis included automatic segmentation of the mandible, obtainment of sections perpendicular to the dental arch, and structural analysis of the trabecular bone in each section. We calculated the ratio between the volume of bone and the total volume of the section, the thickness, the trabecular number, and the mean attenuation in Hounsfield units. We analyzed the differences among different tooth types (incisors, canines, premolars, and molars) and between present and absent teeth. RESULTS: We found statistically significant differences between different tooth types and between sections in which teeth were present or absent. Incisors had a greater ratio of trabecular bone; the ratio of trabecular bone progressively decreased from the incisors to the canines, premolars, and molars. The ratio of trabecular bone was greater in sections in which teeth were absent than in those in which teeth were present. CONCLUSIONS: The method allows to quantify the structural properties of alveolar bone from multidetector computed tomography images. Our results provide an objective picture of the bone substrate that can be useful for planning and following up dental implant procedures.


Asunto(s)
Proceso Alveolar/diagnóstico por imagen , Arco Dental/diagnóstico por imagen , Tomografía Computarizada Multidetector/métodos , Radiografía Dental/métodos , Adulto , Proceso Alveolar/anatomía & histología , Análisis de Varianza , Arco Dental/anatomía & histología , Femenino , Humanos , Masculino , Radiografía Panorámica/métodos , Estudios Retrospectivos , Diente/diagnóstico por imagen , Pérdida de Diente/diagnóstico por imagen
9.
J Prosthodont Res ; 63(2): 239-244, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30658907

RESUMEN

PURPOSE: Computed tomography (CT) imaging for three-dimensional (3D) printed models may improve the quality of surgical preoperative plans. Although metal objects can cause artifacts in CT images, integration of CT and digital dental arch imaging may solve this problem. The present study aimed to evaluate effects of the number of metal restorations and mandibular position during CT imaging on accuracy of reproduced models. METHODS: Stereolithography datasets from three sets of dental models having different numbers of metal restorations were obtained using a laboratory digitizing device (control) and CT equipment (nonintegrated data). CT scanning was performed under two conditions: intercuspal position (closed) and separated using paraffin wax (open). Nonintegrated data after metal artifact removal were separated into maxillary and mandibular dentition groups. The occlusal part of the control dentition and nonintegrated data were superimposed and integrated (integrated data). The root mean square (RMS) between the control and stereolithography data was calculated and analyzed with three-way analysis of variance and t-test with Bonferroni correction. RESULTS: Increasing numbers of metal restorations resulted in increase in metal artifacts and RMS values. Moreover, the RMS of the closed dataset was significantly greater than that of the open dataset because of the creation of artificial occlusal surfaces. The RMSs of the integrated datasets were significantly smaller than those of the nonintegrated datasets, except for the open model without metal restorations. CONCLUSIONS: Accuracies of reproduced maxillary and mandibular models decreased with increasing numbers of metal restorations and in the closed mandibular position during CT scanning.


Asunto(s)
Arco Dental/diagnóstico por imagen , Materiales Dentales , Modelos Dentales , Restauración Dental Permanente , Mandíbula , Metales , Radiografía Dental , Tomografía Computarizada por Rayos X , Artefactos , Humanos , Impresión Tridimensional , Cirugía Bucal
10.
Dentomaxillofac Radiol ; 48(4): 20180354, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30604650

RESUMEN

OBJECTIVES: This study aimed to develop new image receptor-holding instruments with appropriate horizontal X-ray beam angulation, based on the anatomical data of posterior region interproximal surfaces derived from archived CT images. METHODS: CT images of 92 patients with sound upper and lower dental arches were collected from our CT database and analyzed to determine the angles between the tangential interproximal contact line and the central groove line of posterior teeth. The average angle for each site was calculated and used to modify instruments using a three-dimensional printer. The utilities of the conventional and the modified instruments for viewing proximal surfaces were compared using two dry skulls. RESULTS: The right and left sides of each site, except for the lower second premolar and first molar sites, did not differ significantly. The difference between the sites was 2.0°; hence, we calculated mean values for the two sides at each site. In the maxilla, the angles of the first and second premolar, second premolar and first molar, and first and second molar to the groove line were 83.9° (±5.4°), 84.4° (±3.9°), 81.6° (±5.1°), while those in the mandible were 85.0° (±9.2°), 85.0° (±4.0°), and 90.6° (±4.9°), respectively. The holding instruments modified to 80° demonstrated better proximal viewing ability in the upper molar region than conventional instruments. CONCLUSIONS: The mean angles of the interproximal surfaces were determined from CT data. The image receptor holding-instruments were modified according to these angles to allow appropriate X-ray angulation, which facilitated improved observation of the proximal surfaces of teeth in the posterior region in this pilot in vitro study.


Asunto(s)
Arco Dental , Diente Molar , Radiografía Panorámica , Arco Dental/diagnóstico por imagen , Humanos , Diente Molar/diagnóstico por imagen , Radiografía , Rayos X
11.
Med. oral patol. oral cir. bucal (Internet) ; 24(1): e89-e95, ene. 2019. ilus, graf, tab
Artículo en Inglés | IBECS | ID: ibc-180411

RESUMEN

Background: The aim of this study was to compare a conventional technique (elastomeric impression material - EIM) and a digital technique (scanner digital model - SDM) on a six-analog master model (MM) to determine which was the most exact. Material and Methods: Twenty impressions were taken of a master model (EIM) and twenty scanned impressions (SDM) (True Definition). A coordinate measuring machine (CMM) was used to measure the distances between adjacent analogues (1-2, 2-3, 3-4, 4-5, 5-6), intermittently positioned analogues (1-4, 3-6) and the most distal (1-6). Reference values were established from the master model, which were compared with the two impression techniques. The significance level was established as 5% (p<0.05). Results: The precision of each technique was compared with MM. For adjacent analogues (1-2), no significant differences were found between EIM-MM (p=0,146). For intermittently positioned analogues (1-4), SDM did not show significant differences with MM (p=0.255). For the distance between distal analogues (1-6), significant differences were found between both tecniques and MM (p=0.001). Conclusions: In a clinical situation with < three implants, EIM is more exact than SDM, but in cases of four implants SDM is more exact. For rehabilitations (> four implants), neither technique can be considered accurate although error falls within the tolerance limits established in the literature (30-150μm)


No disponible


Asunto(s)
Humanos , Implantación Dental Endoósea/métodos , Técnica de Impresión Dental , Diseño de Prótesis Dental/métodos , Elastómeros , Técnicas In Vitro/métodos , Modelos Anatómicos , Arco Dental/diagnóstico por imagen
12.
Congenit Anom (Kyoto) ; 59(1): 11-17, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29691907

RESUMEN

Turner syndrome is associated with an X chromosome abnormality in women and is characterized by infantilism, congenital webbed neck, and cubitus valgus. The aim of this study was to determine the maxillofacial morphology and oral characteristics of Japanese girls (mean age, 8.5 years) with Turner syndrome and early mixed dentition. Lateral cephalograms obtained at the first visit were used to analyze maxillofacial morphology. Oral characteristics were identified using orthopantomograms, intraoral photographs, and study casts. All patients received growth hormone. Lateral cephalograms showed a retrognathic maxilla and mandible and a small gonial angle. Nine patients had a high-arched palate. Nine patients had class II first molar relationship occlusion and one had mesial step-type occlusion. Three patients showed ectopic eruption of the maxillary first permanent molar accompanied by resorption of the maxillary second primary molar. Eruption of the permanent teeth tended to occur early. The median mesiodistal diameter of the maxillary central incisor was smaller than the Japanese norm. Ectopic eruption of the maxillary first permanent molar may be caused by lack of eruption space and a discrepancy between bone growth and timing of tooth maturation.


Asunto(s)
Arco Dental/patología , Cara/anomalías , Mandíbula/anomalías , Maxilar/anomalías , Síndrome de Turner/patología , Cefalometría , Niño , Arco Dental/diagnóstico por imagen , Dentición Mixta , Cara/diagnóstico por imagen , Femenino , Hormona del Crecimiento/uso terapéutico , Humanos , Incisivo/anomalías , Incisivo/diagnóstico por imagen , Cariotipo , Maloclusión/diagnóstico por imagen , Maloclusión/patología , Mandíbula/diagnóstico por imagen , Maxilar/diagnóstico por imagen , Diente Molar/anomalías , Diente Molar/diagnóstico por imagen , Radiografía Panorámica , Erupción Dental/fisiología , Síndrome de Turner/diagnóstico por imagen , Síndrome de Turner/tratamiento farmacológico , Síndrome de Turner/genética
13.
Artículo en Inglés | MEDLINE | ID: mdl-31888225

RESUMEN

AIMS: The study aims to assess the accuracy of digital planning in dentistry, evaluating the characteristics of different intraoral 3D scanners and comparing it with traditional imaging 2D recording methods. Specifically, using computer aided design (CAD) software and measuring inside CAD software, authors want to verify the reliability of different models obtained with different techniques and machines. METHODS: 12 patients that needed aesthetic restorative treatment were enrolled in the study. All the patients underwent recording data of the height and width dental elements 1.1, 1.2, and 1.3 size using different technologies and comparing 2D with 3D methods. A T test was then applied in order to verify whether there was a statistically significant difference between the measurements obtained, comparing the different tools data (Emerald, TRIOS, Photogrammetry and DSS (Digital Smile System)) with the reference values. RESULTS: No significant differences emerged in the measurements made with the different scanners (Trios 3Shape ®, Planmeca Emerald ®) and photogrammetry. Therefore, what should be underlined regarding the 2D measurements is the speed and simplicity compared to all 3D techniques, so this work can help to better define the field of application and the limits connected to 2D techniques, giving a good window of the technique. CONCLUSIONS: The low number of patients is not sufficient to provide statistically significant results, but the digital planning future prospects seem to be promising. This study results highlighted how a photogrammetric scanner for dental arches would only have a much smaller shooting field size and greater accuracy. Despite these considerations, the photogrammetric facial scanner provided excellent results for the measurement of individual teeth, showing a great versatility of use.


Asunto(s)
Diseño Asistido por Computadora/normas , Arco Dental/diagnóstico por imagen , Técnica de Impresión Dental/normas , Imagenología Tridimensional/normas , Fotografía Dental/normas , Prostodoncia/métodos , Realidad Virtual , Humanos , Reproducibilidad de los Resultados , Programas Informáticos/normas
14.
Orthod Fr ; 89(4): 411-420, 2018 12.
Artículo en Francés | MEDLINE | ID: mdl-30565559

RESUMEN

INTRODUCTION: Enlarged adenoids are often associated with oral breathing. The latter can impact the dental arches. The purpose of this study was to determine the relationships between dental arch measurements and the size of adenoids. MATERIALS AND METHODS: A cross-sectional study was carried out on 86 children. The dimensions of the adenoids were determined from nine radiographic evaluation methods and the dental arch measurements made on the casts. The association between the grade of adenoids and the dental arch measurements was sought by Spearman correlation. That between the quantitative variables assessing adenoids and dental arch measurements was sought by Pearson correlation. The strength of these associations was analyzed using Cohen's values in 1988. The significance was set at p = 0.05. RESULTS: Palatal depth was significantly and positively correlated with adenoid grade according to the method of Holmberg and Linder-Aronson (rho = 0.55, p = 0.005) and with the adenoid measurements according to the methods of Kemaloglu, Fujioka, Johannesson, De Menezes and Maran with r respectively equal to 0.65, 0.59, 0.63, 0.47, 0.74; and p respectively equal to 0.001, 0.002, 0.001, 0.019, and < 0.001. It was also significantly but negatively correlated with the adenoids measurements according to Hibbert's method (r = -0.52, p = 0.008). Overbite was significantly and negatively correlated with adenoid dimension using the De Menezes method (r = -0.541, p = 0.006). DISCUSSION: The strength of the associations shows that using respectively Maran and De Menezes methods can allow to better highlight the association between the dimensions of the adenoids and the palatal depth and the overbite.


Asunto(s)
Tonsila Faríngea/anatomía & histología , Tonsila Faríngea/patología , Cefalometría , Arco Dental/anatomía & histología , Arco Dental/patología , Tonsila Faríngea/diagnóstico por imagen , Cefalometría/métodos , Niño , Estudios Transversales , Arco Dental/diagnóstico por imagen , Femenino , Humanos , Hipertrofia/patología , Masculino , Nasofaringe/anatomía & histología , Nasofaringe/diagnóstico por imagen , Nasofaringe/patología , Odontometría/métodos , Tamaño de los Órganos , Sobremordida/diagnóstico , Sobremordida/patología
15.
Dental Press J Orthod ; 23(5): 39.e1-39.e13, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30427499

RESUMEN

INTRODUCTION: The selection of appropriate sites for miniscrew insertion is critical for clinical success. OBJECTIVES: The aim of the present study was to evaluate how interradicular spaces measured on panoramic radiograph compare with Cone-Beam Computed Tomography (CBCT), and how crowding can influence the presence of available space for miniscrew insertion, in order to define a new "safe zones" map. METHODS: A total of 80 pre-treatment panoramic radiographs and 80 CBCT scans with corresponding digital models were selected from the archives of the department of Dentistry, Aarhus University. Crowding was measured on digital models, while interradicular spaces mesial to the second molars were measured on panoramic radiographs and CBCTs. For panoramic radiographs, a magnification factor was calculated using tooth widths measured on digital models. Statistical analyses were performed to investigate the correlation between the amount of crowding and the available interradicular space. Visual maps showing the amount of interradicular spaces measured were drawn. RESULTS: The most convenient interradicular spaces are those between the second molar and the first premolar in the mandible, and between the central incisors in the maxilla. However, some spaces were revealed to be influenced by crowding. CONCLUSIONS: Calibration of panoramic radiographs is of utmost importance. Generally, panoramic radiographs underestimate the available space. Preliminary assessment of miniscrew insertion feasibility and the related selection of required radiographs can be facilitated using the new "safe zone" maps presented in this article.


Asunto(s)
Tornillos Óseos , Arco Dental/diagnóstico por imagen , Diente Molar/diagnóstico por imagen , Métodos de Anclaje en Ortodoncia/métodos , Adolescente , Adulto , Calibración , Niño , Tomografía Computarizada de Haz Cónico , Arco Dental/anatomía & histología , Implantación Dental/métodos , Femenino , Humanos , Masculino , Mandíbula/diagnóstico por imagen , Maxilar/diagnóstico por imagen , Diente Molar/anatomía & histología , Radiografía Panorámica , Estudios Retrospectivos , Adulto Joven
16.
Am J Orthod Dentofacial Orthop ; 154(4): 495-503, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30268260

RESUMEN

INTRODUCTION: The objective of this study was to compare the maxillary transverse dimensions between subjects with impacted maxillary canines and subjects without canine impactions, with similar vertical and sagittal features. METHODS: In this retrospective study, 86 cone-beam computed tomography images of subjects with impacted maxillary canines (45 unilateral, 41 bilateral) and 67 images of subjects without dental impactions (control group) matched by similar vertical (NSAr, SArGo, ArGoMe) and sagittal (ANB, SNA, APDI) skeletal characteristics, were analyzed. The maxillary width was measured at 4 levels: first molar basal width, first molar alveolar width, first premolar basal width, and first premolar alveolar width. Group comparisons were performed with analysis of variance and post-hoc Scheffé tests. The influence of group features on the transverse dimensions was evaluated by a multiple linear regression analysis. RESULTS: Groups with unilateral and bilateral impacted maxillary canines showed significantly smaller first molar basal widths, first molar alveolar widths, and first premolar alveolar widths compared with the control group (P = 0.030, P <0.001, and P <0.001, respectively). First premolar basal widths were not significantly different among the groups. CONCLUSIONS: Subjects with unilateral or bilateral impacted maxillary canines have smaller maxillary transverse dimensions than do subjects without impaction. Orthodontists should consider the relationship of maxillary width and canine impaction during diagnosis and treatment planning.


Asunto(s)
Tomografía Computarizada de Haz Cónico/métodos , Diente Canino/anomalías , Diente Canino/diagnóstico por imagen , Maxilar/anatomía & histología , Maxilar/diagnóstico por imagen , Diente Impactado/diagnóstico por imagen , Diente Impactado/patología , Adolescente , Adulto , Factores de Edad , Análisis de Varianza , Puntos Anatómicos de Referencia , Diente Premolar/anatomía & histología , Diente Premolar/diagnóstico por imagen , Cefalometría , Niño , Arco Dental/diagnóstico por imagen , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Incisivo/diagnóstico por imagen , Modelos Lineales , Masculino , Diente Molar/anatomía & histología , Diente Molar/diagnóstico por imagen , Estudios Retrospectivos , Factores Sexuales , Técnicas de Movimiento Dental , Adulto Joven
17.
Am J Orthod Dentofacial Orthop ; 154(4): 504-516, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30268261

RESUMEN

INTRODUCTION: The objective of this research was to evaluate the buccal bone plate and root length of maxillary permanent first molars using cone-beam computed tomography after maxillary expansion with different activation protocols. METHODS: Cone-beam computed tomography images of growing patients were obtained from the orthodontic department of Pontifical Catholic University of Rio Grande do Sul in Brazil. The groups were Haas-type 2/4 turns, Haas-type 4/4 turns, hyrax-type 2/4 turns, and hyrax-type with alternate rapid maxillary expansions and constrictions (alt-RAMEC) 4/4 turns a day. Tooth length, periodontal insertion, alveolar bone thickness, and intermolar distances were evaluated. The data at the start of treatment and 6 months later were compared using generalized linear models. The intergroup differences were determined by univariate analysis of variance with the Bonferroni adjustment. RESULTS: Tooth length was significantly shortened after expansion in all groups (-0.28 to -0.51 mm), except for the alt-RAMEC group. Bone level variables (bone level and bone level at the tooth tip) changed statistically in all groups, except for the Haas 4/4 turns group. There was significant periodontal attachment loss after rapid maxillary expansion with the hyrax/alt-RAMEC (5.09 mm). The hyrax/alt-RAMEC and hyrax groups had more dehiscences, fenestrations, and exposures of the root. CONCLUSIONS: The consequence of rapid maxillary expansion using the hyrax was alveolar bone resorption, especially in the hyrax/alt-RAMEC group, whereas the Haas expander caused mild root resorption.


Asunto(s)
Placas Óseas/efectos adversos , Tomografía Computarizada de Haz Cónico/métodos , Maxilar/anatomía & histología , Maxilar/diagnóstico por imagen , Técnica de Expansión Palatina/efectos adversos , Raíz del Diente/anatomía & histología , Raíz del Diente/diagnóstico por imagen , Adolescente , Pérdida de Hueso Alveolar , Proceso Alveolar/diagnóstico por imagen , Análisis de Varianza , Brasil , Niño , Arco Dental/anatomía & histología , Arco Dental/diagnóstico por imagen , Femenino , Humanos , Imagenología Tridimensional , Masculino , Diente Molar/anatomía & histología , Diente Molar/diagnóstico por imagen , Métodos de Anclaje en Ortodoncia/efectos adversos , Métodos de Anclaje en Ortodoncia/instrumentación , Ortodoncia Correctiva/instrumentación , Ortodoncia Correctiva/métodos , Técnica de Expansión Palatina/instrumentación , Diente/anatomía & histología , Diente/diagnóstico por imagen , Raíz del Diente/patología
18.
Am J Orthod Dentofacial Orthop ; 154(4): 524-534, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30268263

RESUMEN

INTRODUCTION: The purpose of this study was to evaluate the short-term impact of rapid maxillary expansion (RME) on the eruption paths of ectopically and normally erupting maxillary canines in the mixed dentition. METHODS: Thirty-two patients with 49 ectopically erupting canines (EEC group; age, 9.53 ± 1.10 years) and 18 patients with 27 normally erupting canines (NEC group; age, 9.25 ± 1.06 years) underwent RME. Thirty-six subjects with 54 normally erupting canines composed the untreated control group (UC group; age, 9.03 ± 0.72 years). Horizontal, vertical, and angular positions of canines and adjacent teeth were evaluated in the expanded (EEC and NEC groups) and unexpanded (UC group) patients using panoramic radiographs taken at 2 times with a 1-year interval. The radiographic evaluation methods included score ranking and proportional measurements to minimize panoramic radiograph limitations. Statistical comparisons were performed among the groups (P <0.05). RESULTS: Before expansion, the EEC group's canines were significantly closer to the midline, more distant from the occlusal plane, and more mesially angulated than those in the UC group. After expansion, the canine positions in the EEC and UC groups were similar, whereas the NEC group had a more favorable canine position for eruption. The EEC and NEC groups showed similar canine positional changes, whereas the UC group had the smallest changes. The positions of teeth adjacent to the canine were also significantly affected by RME, and these changes may be associated with improvement of the ectopic canine position. CONCLUSIONS: The changes produced by RME reduced the percentage of ectopic eruption paths and maintained the nonectopic eruption percentage.


Asunto(s)
Diente Canino/anatomía & histología , Diente Canino/patología , Técnica de Expansión Palatina/efectos adversos , Resorción Radicular/etiología , Erupción Ectópica de Dientes/etiología , Erupción Dental , Brasil , Niño , Diente Canino/efectos de los fármacos , Arco Dental/diagnóstico por imagen , Dentición Mixta , Femenino , Humanos , Incisivo/anatomía & histología , Incisivo/diagnóstico por imagen , Masculino , Maxilar/diagnóstico por imagen , Maxilar/patología , Radiografía Panorámica , Resorción Radicular/diagnóstico por imagen , Ápice del Diente/anatomía & histología , Ápice del Diente/patología , Erupción Ectópica de Dientes/diagnóstico por imagen , Técnicas de Movimiento Dental/efectos adversos , Raíz del Diente/anatomía & histología , Raíz del Diente/diagnóstico por imagen , Diente Primario
19.
Am J Orthod Dentofacial Orthop ; 154(4): 583-595, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30268268

RESUMEN

INTRODUCTION: Current methods to evaluate root position either are inaccurate (panoramic radiograph) or expose patients to relatively large amounts of radiation (cone-beam computed tomography [CBCT]). A method to evaluate root position by generating an expected root position (ERP) setup was recently reported but has not been validated. The purpose of this study was to quantitatively assess the accuracy and reliability of the ERP setup with adequate statistical power. METHODS: This retrospective study included 15 subjects who had completed phase 2 orthodontic treatment. An ERP setup was generated for all patients after treatment. The ERP setup was compared with the posttreatment CBCT scan, which served as the control. The mesiodistal angulation and buccolingual inclination of all teeth in both the ERP setup and the posttreatment CBCT scan were measured and compared. Bland-Altman analysis was used to assess interoperator reliability, intraoperator reliability, and agreement between the ERP setup and the posttreatment CBCT scan. RESULTS: Bland-Altman plots showed high interoperator and intraoperator reliabilities. These plots also showed strong agreement between the ERP setup and the posttreatment CBCT scan; 11.8% of teeth measured for mesiodistal angulation and 9.6% of teeth measured for buccolingual inclination were outside the ±2.5° range of clinical acceptability. CONCLUSIONS: We validated that the method to generate an ERP setup to evaluate root position for posttreatment orthodontic assessment is accurate and reliable.


Asunto(s)
Tomografía Computarizada de Haz Cónico/métodos , Imagenología Tridimensional/métodos , Ortodoncia Correctiva , Raíz del Diente/anatomía & histología , Raíz del Diente/diagnóstico por imagen , Diente/anatomía & histología , Diente/diagnóstico por imagen , Arco Dental/diagnóstico por imagen , Modelos Dentales , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Modelos Lineales , Proyectos Piloto , Radiografía Panorámica/métodos , Reproducibilidad de los Resultados , Estudios Retrospectivos , San Francisco , Programas Informáticos
20.
Am J Orthod Dentofacial Orthop ; 154(3): 356-364, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30173838

RESUMEN

INTRODUCTION: The aim of this study was to evaluate the mean gingival thicknesses of the maxillary and mandibular anterior regions in subjects with different craniofacial morphologies. METHODS: For each dental arch, 128 periodontally healthy orthodontic patients with normal values of maxillary incisor position (1/NA, angle and distance; and 1/SN, angle) and mandibular incisor position (1/NB, angle and distance; and IMPA) were enrolled in the study. Craniofacial morphology of the participants was evaluated in the sagittal (ANB angle) and vertical directions (SN/GoGn angle) on lateral cephalograms. In the sagittal direction, the subjects were divided into 3 groups as Class I, Class II, and Class III. Each group was classified as low angle, normal, or high angle in the vertical direction. Mean gingival thicknesses of the maxillary and mandibular anterior regions were determined by the ratio of the sum of gingival thickness of the relevant teeth, measured by the transgingival probing technique, to the number of teeth. RESULTS: Mean gingival thicknesses of the maxillary anterior region were 1.173 ± 0.61, 1.103 ± 0.207, and 1.130 ± 0.244 mm in the Class I, Class II, and Class III groups and 1.084 ± 0.150, 1.136 ± 0.247, and 1.159 ± 0.249 mm in the low angle, normal, and high angle groups, respectively. Mean gingival thicknesses of the mandibular anterior region were 0.710 ± 0.156, 0.741 ± 0.176, and 0.691 ± 0.157 mm in the Class I, Class II, and Class III groups and 0.705 ± 0.184, 0.701 ± 0.132, and 0.735 ± 0.174 mm in the low angle, normal, and high angle groups, respectively. No significant difference was found between the groups in terms of the mean gingival thicknesses of the maxillary and mandibular anterior regions. CONCLUSIONS: There was no significant difference between the groups in terms of the mean gingival thicknesses of the maxillary and mandibular anterior regions.


Asunto(s)
Encía/anatomía & histología , Maloclusión/diagnóstico por imagen , Adolescente , Cefalometría , Arco Dental/anatomía & histología , Arco Dental/diagnóstico por imagen , Femenino , Encía/diagnóstico por imagen , Humanos , Masculino , Mandíbula/anatomía & histología , Mandíbula/diagnóstico por imagen , Maxilar/anatomía & histología , Maxilar/diagnóstico por imagen , Fenotipo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA