Face comparison analysis of patients with orthognathic surgery treatment using cloud computing-based face recognition application programming interfaces.

INTRODUCTION: This study aimed to investigate whether the postoperative change in patients after orthognathic surgery, whose facial aesthetics was affected, led to detectable differences using Microsoft Azure, Amazon Web Services Rekognition, and Face++, which were commercially available face recognition systems. METHODS: Photographs of 35 patients after orthognathic surgery were analyzed using 3 well-known cloud computing-based facial recognition application programming interfaces to compute similarity scores between preoperative and postoperative photographs. The preoperative, relaxed, smiling, profile, and semiprofile photographs of the patients were compared separately to validate the relevant application programming interfaces. Patient characteristics and type of surgery were recorded for statistical analysis. Kruskal-Wallis rank sum tests were performed to analyze the relationship between patient characteristics and similarity scores. Multiple-comparison Wilcoxon rank sum tests were performed on the statistically significant characteristics. RESULTS: The similarity scores in the Face++ program were lower than those in the Microsoft Azure and Amazon Web Services Rekognition. In addition, the similarity scores were higher in smiling photographs. A statistically significant difference was found in similarity scores between relaxed and smiling photographs according to different programs (P <0.05). For all 3 facial recognition programs, comparable similarity scores were found in all photographs taken before and after surgery across sex, type of surgery, and type of surgical approach. The type of surgery and surgical approach, sex, and amount of surgical movement did not significantly affect similarity scores in any facial recognition programs (P >0.05). CONCLUSIONS: The similarity scores between the photographs before and after orthognathic surgery were high, suggesting that the software algorithms might value measurements on the basis of upper-face landmarks more than lower-face measurements.

Evaluation of the Efficacy of Different Cleaning Methods for Orthodontic Thermoplastic Retainers in terms of Bacterial Colonization.

OBJECTIVE: This study investigated the antimicrobial efficacy of three different cleaning methods on Streptococcus mutans (SM) and Lactobacillus (LB) bacteria colonization in vivo. The three different cleaning methods were applied by volunteers on clear vacuum formed retainers (VFRs). METHODS: In this prospective, cross-over study, a total of 21 volunteers were included. All VFRs used by the volunteers were cleaned using three different cleaning methods in a sequence. These methods were peroxide-based cleanser tablets (PBCTs) plus brushing, control (only brushing), and vinegar plus brushing, respectively. The obtained salivary, VFR material, and periodontal data were statistically compared by factorial design repeated measures analysis of variance. RESULTS: The SM and LB bacteria counts on VFRs after using both PBCTs and vinegar were statistically similar (p>0.05), but bacteria counts were statistically lower than the control method (p<0.01). There were no statistically significant differences between the SM and LB bacteria counts in saliva samples taken before and after the application of the cleaning methods (p>0.05). Similarly, there were no significant differences between periodontal data obtained from plaque and bleeding indices at all study times. The periodontal pocket depth gradually decreased in the successively performed cleaning applications (p<0.05). CONCLUSION: The application of PBCTs and vinegar to VFRs at sequential time intervals resulted in similar bacteria counts. The higher LB counts and similarly higher SM counts on the VFR samples indicate that mechanical cleaning only (control method) is not adequate to obtain hygiene. Salivary flora was not correlated with bacteria counts of VFRs.