RESUMO
Purpose: The assessment of bone age has applications in a wide variety of fields: from orthodontics to immigration. The traditional non?automated methods are time?consuming and subject to inter? and intra?observer variability. This is the first study of its kind done on the Indian population. In this study, we analyse different pre?processing techniques and architectures to determine the degree of maturation (i.e. cervical vertebral maturation [CVM]) from cephalometric radiographs using machine learning algorithms. Methods: Cephalometric radiographs—labelled with the correct CVM stage using Baccetti et al. method—from 383 individuals aged between 10 and 36 years were used in the study. Data expansion and in?place data augmentation were used to handle high data imbalances. Different pre?processing techniques like Sobel filters and canny edge detectors were employed. Several deep learning convolutional neural network (CNN) architectures along with numerous pre?trained models like ResNet?50 and VGG?19 were analysed for their efficacy on the dataset. Results: Models with 6 and 8 convolutional layers trained on 64 × 64–size grayscale images trained the fastest and achieved the highest accuracy of 94%. Pre?trained ResNet?50 with the first 49 layers frozen and VGG?19 with 10 layers frozen to training had remarkable performances on the dataset with accuracies of 91% and 89%, respectively. Conclusions: Custom deep CNN models with 6–8 layers on 64 × 64–sized greyscale images were successfully used to achieve high accuracies to classify the majority classes. This study is a launchpad in the development of an automated method for bone age assessment from lateral cephalograms for clinical purposes.
RESUMO
Objective To evaluate the soft tissue profile in adults with unoperated isolated cleft palate. Methods Twenty patients older than 16 years(median age,18.4) with unoperated isolated cleft palate were enrolled.Soft tissue lateral cephalograms were traced and compared with those of cleft operated patients and class-Ⅰocclusion individuals.The results of various measurements were analyzed with ANOVA by SPSS11.5. Results In adults with unoperated isolated cleft palate,there was restriction at the top of the upper lip,and the antelabrum of upper lip and the lower lip were found normal. Conclusion The soft tissue profile in adults with unoperated isolated cleft palate exhibits almost the same characteristics as the corresponding hard tissue,and there is covering over effect of the soft tissue to some extent.
RESUMO
This study aimed at investigating the skeletal, dentoalveolar, and soft tissue changes of Class III malocclusion cases treated by second molar extraction. The lateral cephalograms of 15 subjects with moderate Class III malocclusion by average ANB -1.4degrees and IMPA 85degrees were traced and the computerized superimposition of average craniofacial change was made. The data was gathered and statistically analyzed. The results were as follows: 1. Lower anterior facial height/anterior facial height increased by 0.6%(P<0.01), mandibular plane increased by 1.5degrees (P<0.05). 2. There was a slightly downward & backward rotation of the mandible. 3. Lower first molar tipped distally by 4.06mm(P<0.001), lower anterior teeth lingually tipped by 3.2degrees (P<0.05). 4. Retracted lower lip improved facial profile. This study may suggest that second molar extraction could be effective for a moderate Class III malocclusion to make distalization of the lower first molar easier and avoid severe lingual tipping of the lower incisor, if the lower third molar has a normal shape, good direction of eruption and adequate time for lower second molar extraction.
Assuntos
Incisivo , Lábio , Má Oclusão , Mandíbula , Dente Molar , Dente Serotino , DenteRESUMO
The purpose of this study was to assess the skeletal characteristics of the maxillofacial norms and the interpretation of craniofacial relations in Korean adults by applying the Ricketts Analysis. The factors of the applied lateral cephalometric measurements were composed of the 10 factor analysis (Summary Analysis) and 7 internal structures to be suggested by Ricketts. Lateral cephalograms were obtained from 60 subjects over 21 years old that consisted of 30 males and 30 females with normal occlusion, acceptable profile. The results were as follow: 1. The tables of means, standard deviations in each item and sex were made. 2. The author performed whether there was significance (P<0.05) between the registered male and female's measurement in each item.