Three-dimensional Analysis of Lip Changes in Response To Simulated Maxillary Incisor Advancement

Abstract

Objective: To assess the immediate response of lips in three dimensions (3D) resulting from simulated maxillary incisor advancement. Materials and Methods: Incremental maxillary incisor advancement was simulated by placing wax of increasing thickness (+2 mm, +4 mm, +6 mm) on the incisors of 20 participants, and the induced lip changes were recorded using 3D stereophotogrammetry. The induced displacement of lip landmarks was quantified using 3D image analysis software. Data were analyzed using a repeated-measures analysis of variance (ANOVA) after adjusting for age and sex of the study participants. Results: A large interindividual variation in lip response to simulated incisor advancement was observed. A significant overall effect on 3D lip changes was found for increasing values of simulated incisor advancement (F = 13.2; P < .001) as well as significant differences between anatomical landmarks of the lip (F = 7.4; P < .01). Most points moved outward and anterosuperiorly, except the midpoint and corners of the lip. Greatest movement was observed in the sagittal plane, followed by the vertical and transverse planes. Conclusions: Maxillary incisor advancement significantly affects upper lip change in three planes of space: particularly the anteroposterior plane, in which the response to simulated advancement appears to be nonlinear.

Evaluation of automated cephalometric analysis based on the latest deep learning method

“…1,2 In orthodontics, there have also been efforts to utilize machine learning techniques in a variety of ways, one of which was the automated identification of cephalometric landmarks via artificial intelligence (AI). [3][4][5][6][7][8][9][10] Although research using three-dimensional images has attracted attention, [11][12][13] the two-dimensional cephalometric image is still important and is the most commonly utilized tool in orthodontics for diagnosis, treatment planning, and outcome prediction. 3,[14][15][16][17][18] As more attempts were made to incorporate AI into cephalometric analysis, worldwide AI challenges began in 2014 at the International Symposium on Biomedical Imaging conferences under the support of the Institute of Electrical and Electronics Engineers (IEEE ISBI).…”

Immediate effect of clear aligners and fixed appliances on perioral soft tissues and speech

“…All participants provided written informed consent prior to the investigation. A power calculation for estimation of the sample size was conducted, using prior studies to determine the parameters in this power calculation, with mean effect size 0.490, α at 0.05 and power of 80% 2,26 . It was determined that 40 participants were needed.…”

“…All clinical procedures were performed by the same clinician (DW) throughout the study. Each 3D photograph was examined for acquisition errors; inaccuracies such as participant smiling, pursing of the lips or mentalis strain resulted in deletion and a new image was acquired 26,28 …”

New analysis and classiŢcation of Angle’s class II malocclusion varieties during the mixed dentition period

“…In the last decade, digital 3D diagnostic methods and treatment technologies have entered the daily li fe of orthodontic clinical practice [1][2][3]. However, lateral and frontal cephalogram followed by 2D cephalometry remains the main method of diagnostics and decisionmaking regarding the method of treatment among orthodontists [4][5].…”