An anatomical study of the risorius in Asians and its insertion at the modiolus

Safety considerations for treating the parotid and submandibular glands with neuromodulators for facial slimming

BACKGROUND

Neuromodulators have predominantly been used for the treatment of upper facial lines, but their use has expanded to include lower face and neck treatments. However, the injection sites for these treatments are based on skin surface landmarks, which may pose risks to nearby structures and result in undesired outcomes.

OBJECTIVE

To investigate the spatial relationship between the FDA-approved skin surface landmarks for neuromodulator injections in the parotid and submandibular glands and the topographical anatomy of critical facial structures such as the facial artery, facial vein, external carotid artery, and retromandibular vein.

MATERIALS AND METHODS

A cross-sectional retrospective analysis was conducted on contrast-enhanced cranial CT scans. The scans were analyzed for the morphology and location of the parotid and submandibular glands. Measurements were taken for gland volume, craniocaudal extent, anterior-posterior extent, and distances between the skin surface and gland capsule or nearby structures such as arteries.

RESULTS

The study sample consisted of 53 subjects, including 7 males and 46 females, with a mean age of 36.91 years and a mean BMI of 23.28 kg/m2 . The mean volume of the parotid gland was 31.9 ± 3.0 cc in males and 28.5 ± 3.6 cc in females with p < 0.001, while the mean volume of the submandibular gland was 18.2 ± 2.0 cc in males and 14.5 ± 3.4 cc in females with p < 0.001. The mean distances between skin surface and the gland capsule were 5.98 ± 2.2 and 8.84 ± 4.0 mm for the parotid and submandibular gland, respectively. This distance increased with higher age and higher BMI values in a statistically significant manner with p < 0.001.

CONCLUSION

The distances between FDA-approved skin surface landmarks and the parotid and submandibular glands varied significantly depending on gender, age, and BMI. Optimal injection depth and location for neuromodulator treatments cannot be generalized based on these landmarks alone, emphasizing the need for real-time ultrasound imaging guidance.

Use of LetibotulinumtoxinA for Aesthetic Treatment of Asians: A Consensus

Treatment of wrinkles and dynamic lines with botulinum toxin has been a routine practice for years in aesthetic clinical settings. The effective treatment of wrinkles requires a comprehensive understanding of facial expression muscles and their interactions, the mechanism of action of botulinum toxin, and individual patient preferences. The dose adjustment practice and injection technique of physicians are affected by cultural differences; most Asian patients prefer natural-looking results. This article aims to present an expert consensus on the injection sites, doses, and levels of botulinum toxin for various indications in Asians, with the hope of providing guidance to some clinicians. This consensus paper reviews LetibotulinumtoxinA for patient evaluation, dosage, and delivery techniques in Asians from the time LetibotulinumtoxinA was approved up to December 2022. Panelists proposed individualized treatment plans for botulinum toxin type A (BTxA) treatments in 3 areas-wrinkle removal, contour adjustment, and face lifting-for Asians based on their extensive experience and knowledge of facial anatomy. When using a different BTxA, clinicians should start with a conservative dose and carefully individualize the treatment for each patient, and adjust it according to feedback to obtain a higher satisfaction level.

LEVEL OF EVIDENCE: 5

Face painting as an anatomical learning tool based on individual ultrasonographic examination

Considering the shift to online education during the COVID-19 pandemic, new and easily accessible educational videos and content on clinical anatomy are necessary. This study utilized numerous references and data on the anatomy of Asian facial muscles and blood vessels to accurately depict human anatomy through face painting. It aimed to provide clinicians accurate educational video content on anatomy to help prevent possible complications during noninvasive facial and surgical procedures. A 26-year-old Korean-Chinese male volunteer was used as a face painting model. The location of the blood vessels of the face was confirmed through ultrasonography images using a real-time two-dimensional B-mode. The model's face was painted by an artist majoring in anatomy. To reveal most anatomical structures on both sides of the face, the left side showed the structures observed when the skin and superficial fat layer are removed, and the right side revealed the deeper layer structures that can be seen when some muscles are cut. Fifteen superficial and deep muscles important in esthetic procedures were meticulously painted on the face. The face painting took a total of 6 h, and the video was edited to 5 min. This study merged the advantages of 2D and 3D by painting directly on the skin surface of a living model. Thus, it can provide more dynamic surface anatomy data. These contents inform clinicians about 3D anatomic location, which can help avoid complications when performing clinical procedures on the face.

A Different Pattern of Arrangement of the Risorius Muscle Fibers: A Case Report

The risorius is a very thin muscle and is one of the superficial muscles of facial expression, which is reported as being inconstant, as it is absent in most people, and is a unique muscle; once it has no bony origin. The study aimed to report a different pattern of arrangement of the risorius muscle fibers. During a routine Anatomy class, a different pattern of arrangement of the risorius muscles fibers was found from the observation of an adult (around 40 years old) male cadaver hemiface (right side). After dissections, it was possible to note that the arrangement of the risorius muscle fibers on the surface of the masseteric fascia was formed in different arrangements formed in two bands. In conclusion, the risorius muscle fibers are not always easily distinguishable, and detailed knowledge of their different morphological arrangement is essential when planning and performing facial procedures.

A combined method of oral commissure lifting for perioral rejuvenation in Asians

BACKGROUND

A drooping oral commissure shows an appearance of ageing and sadness. To improve it with less complications has become a rising aesthetic concern for Asians.

OBJECTIVES

To share our method for oral commissure lifting by a combined technique including skin resection, oral commissure suspension, and dissection of the depressor anguli oris muscle (DAO), and to present the follow-up outcomes.

METHODS

This was a retrospective study of patients who underwent oral commissure lifting between 10/2012 and 03/2019 at the Department of Plastic Surgery, Peking University Third Hospital. The patients were routinely followed at 1 week, 1 month, and over 6 months. After operation, cases with the cheilions (oral commissure points) located above the ipsilateral lateral thickening points were considered to be effective, with the points at the same level were considered to be mildly effective, and with the cheilions below the ipsilateral lateral thickening points were considered to be ineffective treatment.

RESULTS

Surgery took around an hour. Swelling subsided within 9.2±3.4 days. The red color of the scar disappeared within 3.7±1.5 months and the natural facial expression was restored within 7.9±2.6 weeks. Among the 159 cases, 125 (78.6%) were obviously effective, 21 (13.2%) were mildly effective, and 13 (8.2%) were ineffective. After the first operation, 112 patients (70.4%) were satisfied, 39 patients (24.5%) were basically satisfied, and eight patients (5.0%) were unsatisfied.

CONCLUSIONS

The combined technique for the oral commissure lifting displayed a significant effect with little complication in Asian patients.