Impact of orthodontic-induced facial morphology changes on aesthetic evaluation: a retrospective study.

BACKGROUND: The profound influence of orthodontic treatments on facial aesthetics has been a topic of increasing interest. This study delves into the intricate interplay between orthodontic treatments, facial feature alterations, and aesthetic perceptions. METHODS: A total of 73 patients who had undergone orthodontic treatment were included in this study. Facial photographs were taken before and after treatment. Ten orthodontists provided facial aesthetic ratings (FAR) for each patient's frontal, profile, and overall views. 48 facial landmarks were manually placed by the orthodontists and normalized using Generalized Procrustes analysis (GPA). Two types of phenotypes were derived from facial landmarks. Global facial phenotypes were then extracted using principal component analysis (PCA). Additionally, 37 clinical features related to aesthetics and orthodontics were extracted. The association between facial features and changes in FAR after orthodontic treatment was determined using these two types of phenotypes. RESULTS: The FAR exhibited a high correlation among orthodontic experts, particularly in the profile view. The FAR increased after orthodontic treatment, especially in profile views. Extraction of premolars and orthognathic surgery were found to result in higher FAR change. For global facial phenotypes, the most noticeable changes in the frontal and profile views associated with FAR occurred in the lip area, characterized by inward retraction of the lips and slight chin protrusion in the profile view, as well as a decrease in lip height in the frontal view. The changes observed in the profile view were statistically more significant than those in the frontal view. These facial changes were consistent with the changes from orthodontic treatment. For clinical features, two profile features, namely pg.sm.hori and pg.n.ls, were found to be associated with FAR following orthodontic treatment. The highest FAR scores were achieved when pg.sm.hori was at 80° and pg.n.ls was at 8°. On the other hand, frontal clinical features had a subtle effect on FAR during orthodontic treatment. CONCLUSIONS: This study demonstrated that orthodontic treatment improves facial aesthetics, particularly at lip aera in the profile view. Profile clinical features, such as pg.sm.hori and pg.n.ls, are essential in orthodontic treatment which could increase facial aesthetics.

'Spin' among abstracts of randomised controlled trials in sleep medicine: A research-on-research study.

STUDY OBJECTIVES: 'Spin', using reporting strategies to distort study results, can mislead readers of medical research. This study aimed to evaluate the prevalence and characteristics of 'spin' among randomised controlled trial (RCT) abstracts published in sleep medicine journals, and to identify factors associated with its presence and severity. METHODS: The search for RCTs published between 2010 and 2020 were conducted in seven reputable journals of sleep medicine. Abstracts of RCTs with statistically nonsignificant primary outcomes were included and analysed for 'spin', according to pre-determined 'spin' strategies. Chi-square tests or logistic regression analyses were performed to detect the association between characteristics of included abstracts and the presence and severity of 'spin'. RESULTS: A total of 114 RCT abstracts were included in this study, of which 89 (78.1%) were identified as having at least one type of 'spin' strategy. Sixty-six abstracts (57.9%) had 'spin' in the Results section, 82 (71.9%) abstracts presented with 'spin' in the Conclusions section. The presence of 'spin' varied significantly among RCTs based on the different categories of research area (P=0.047) and the statistician involvement (P=0.045). Furthermore, research area (P=0.019) and funding status (P=0.033) were significant factors associated with the severity of 'spin'. CONCLUSIONS: The prevalence of 'spin' is high among RCT abstracts in sleep medicine. This raise the need for researchers, editors and other stakeholders to be aware of the issue of 'spin' and make joint efforts to eliminate it in future publications.