Reliability of 3-dimensional surface imaging of the face using a whole-body surface scanner

Botulinum Toxin Type A for Nostril Overexposure: A Prospective Clinical Study Using 3D Scanning

BACKGROUND

Nostril overexposure is a common aesthetic concern among Asian populations, which significantly affects facial harmony. Traditional surgical interventions carry risks such as substantial trauma and visible scarring. This study aims to evaluate the clinical efficacy of Botulinum Toxin Type A (BoNT-A) injections in treating nostril overexposure using three-dimensional (3D) scanning technology.

METHODS

This study recruited 52 patients seeking improvement for nostril overexposure. BoNT-A was injected into the nasal dilator muscles. Changes in nostril cross-sectional area and alar mobility were quantified using 3D scanning technology before treatment and at 4, 12, and 24 weeks post-treatment. Subjective improvements were evaluated by patients and one independent plastic surgery experts using the Global Aesthetic Improvement Scale (GAIS).

RESULTS

A total of 32 patients completed the entire 24-week follow-up period. Post-treatment 3D analysis showed a significant reduction in both nostril cross-sectional area and alar mobility. At 4 weeks post-injection, the nostril area decreased from 89.42 ± 13.21 to 72.50 ± 13.93 mm2 (p < 0.05), and alar mobility decreased from 10.50 ± 3.92 to 4.64 ± 3.09% (p < 0.05). GAIS scores indicated that both patients and expert rated the improvement as significant at 4 weeks. Measurements at 24 weeks approached baseline levels.

CONCLUSION

BoNT-A injections effectively and safely improve nostril overexposure with high patient satisfaction.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Clinical evaluation of the accuracy of two face scanners with different scanning technologies

OBJECTIVES

This study compared the clinical accuracy of two different stationary face scanners, employing progressive capture and multi-view simultaneous capture scanning technologies.

METHODS

Forty dentate volunteers participated in the study. Soft tissue landmarks were marked with a pen on the participants' faces to measure the distances between them. Clinical measurements were manually obtained using a digital vernier caliper by two independent examiners. The participants were then scanned using one of two stationary face scanners: Obiscanner (Fifthingenium), which employs progressive capture technology requiring the subject's head to rotate during image acquisition, or RAYFace (RAY), which utilizes multiple cameras to simultaneously capture a complete 3D image. The scans were imported into mesh-processing software, and digital measurements were taken by the same examiners. Data analysis included pairwise comparison tests and the calculation of the intra-class correlation coefficient (ICC; α = 0.05).

RESULTS

Digital measurements were significantly longer than clinical measurements across all measured distances (p < 0.001). Comparisons between the scanners revealed that vertical measurements using RAYface exhibited greater percentage differences compared to those using Obiscanner (p < 0.05), while horizontal measurements were more variable with Obiscanner than those obtained using RAYface (p < 0.05). Intra-examiner differences were significant for both methods (p < 0.001), although inter-examiner differences were only significant for clinical measurements (p < 0.001), not for digital measurements (p > 0.05). Inter-examiner reliability for digital measurements was high (ICC≥0.99).

CONCLUSIONS

Significant differences were observed in the accuracy of the two stationary face scanners using progressive capture and multi-view simultaneous capture scanning technologies, with each device demonstrating specific strengths and limitations.

CLINICAL SIGNIFICANCE

Although face scanners offer relatively high accuracy and consistency, particularly across different acquisition technologies, careful consideration of their performance characteristics is essential for optimizing accuracy in facial measurements.

Applied Anatomy of the Lower Eyelid Preseptal Space for Treating Ectropion and Retraction with Soft-Tissue Fillers

BACKGROUND

Lower eyelid malposition can result from age-related changes, such as ectropion, or postsurgical changes, such as retraction after lower lid blepharoplasty. The current accepted treatment is surgical, but soft-tissue fillers have been used as well, with good outcome. The underlying anatomy, which is incompletely described, would be useful information for practitioners desiring to provide minimally invasive injections of the lower eyelid. The authors describe a minimally invasive injection technique adjusted to the complex anatomy of the lower eyelid for the treatment of ectropion and retraction of the lower eyelid.

METHODS

A total of 39 periorbital regions of 31 study participants were retrospectively analyzed using photographs before and after reconstruction of the lower eyelid with soft-tissue fillers. Two independent raters assessed the degree of ectropion and lower eyelid retraction (0 to 4, best to worst) before and after the reconstruction and the overall aesthetic improvement using the Periorbital Aesthetic Improvement Scale.

RESULTS

The median degree of ectropion and lower eyelid retraction score improved statistically significantly from 3.00 (SD, 1.5) to 1.00 (SD, 1.0) ( P < 0.001). The mean volume of soft-tissue filler material applied per eyelid was 0.73 cc (SD, 0.5). The median Periorbital Aesthetic Improvement Scale score after the treatment was rated as 4.00 (SD, 0.5), indicating improvement of the periorbital functional and appearance.

CONCLUSIONS

Anatomic knowledge of the lower eyelid and of the preseptal space is of clinical relevance when reconstructing the lower eyelid with soft-tissue fillers. The targeted space provides optimal lifting capacities for improved aesthetic and functional outcome.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Accuracy between 2D Photography and Dual-Structured Light 3D Facial Scanner for Facial Anthropometry: A Clinical Study

(1) Background: Facial scanners are used in different fields of dentistry to digitalize the soft tissues of the patient's face. The development of technology has allowed the patient to have a 3-dimensional virtual representation, facilitating facial integration in the diagnosis and treatment plan. However, the accuracy of the facial scanner and the obtaining of better results with respect to the manual or two-dimensional (2D) method are questionable. The objective of this clinical trial was to evaluate the usefulness and accuracy of the 3D method (a dual-structured light facial scanner) and compare it with the 2D method (photography) to obtain facial analysis in the maximum intercuspation position and smile position. (2) Methods: A total of 60 participants were included, and nine facial landmarks and five interlandmarks distances were determined by two independent calibrated operators for each participant. All measurements were made using three methods: the manual method (manual measurement), the 2D method (photography), and the 3D method (facial scanner). All clinical and lighting conditions, as well as the specific parameters of each method, were standardized and controlled. The facial interlandmark distances were made by using a digital caliper, a 2D software program (Adobe Photoshop, version 21.0.2), and a 3D software program (Meshlab, version 2020.12), respectively. The data were analyzed by SPSS statistical software. The Kolmogorov-Smirnov test revealed that trueness and precision values were normally distributed (p > 0.05), so a Student's t-test was employed. (3) Results: Statistically significant differences (p ≤ 0.01) were observed in all interlandmark measurements in the 2D group (photography) to compare with the manual group. The 2D method obtained a mean accuracy value of 2.09 (±3.38) and 2.494 (±3.67) in maximum intercuspation and smile, respectively. On the other hand, the 3D method (facial scanner) obtained a mean accuracy value of 0.61 (±1.65) and 0.28 (±2.03) in maximum intercuspation and smile, respectively. There were no statistically significant differences with the manual method. (4) Conclusions: The employed technique demonstrated that it influences the accuracy of facial records. The 3D method reported acceptable accuracy values, while the 2D method showed discrepancies over the clinically acceptable limits.

Application of Three-Dimensional Technology in Evaluating the Lower Face Lifting by Regional Platysma Injection with Botulinum Toxin-A

BACKGROUND

Botulinum toxin-A (BTX-A) injection of regional platysma has been utilized in the lower-part elevation and mandibular contour sculpture. However, the relative research, especially in quantitative assessment appears very spare. Our aim is to investigate the efficacy of three-dimensional (3D) technology as a method for regional platysma injection with BTX-A.

MATERIALS AND METHODS

From October 2019 to September 2020, patients with mild or moderate degrees of facial sagging on the lower face were recruited to regional platysma BTX-A injection, and 3D scanning and measurement technology was used to evaluate the difference of curved distances and angels. Patients' improvement was assessed by the global aesthetic improvement scale (GAIS).

RESULTS

A total of 57 patients underwent regional platysma BTX-A injection and 32 patients were followed up successfully. Compared with Pre-operative, postoperative facial reference curves distance and cervico-mental angles had statistical differences (p < 0.05). GAIS suggested that the 3D imaging measurement technology could improve satisfaction.

CONCLUSION

3D technology can evaluate the improvement of the lower face with BTX-A. It provides effective measurement methods and raises satisfaction.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .