Ultrasonographic Evaluation of Facial Artery in the Nasolabial Fold for Gender Differences and Symmetry Between Hemifaces

OBJECTIVES

The aim of this study was to establish the relationship of facial artery with nasolabial fold by color Doppler sonography and to determine facial artery variations and their relationship with age, gender, or hemifaces.

METHODS

The study included 188 patients (94 women, 94 men) aged 18-60 years. Overall, 376 facial arteries in both hemifaces were evaluated for the course within nasolabial fold, symmetry, and relationship with gender.

RESULTS

The mean age of the patients was 39.29 ± 12.81 years. Type A (55.7%) was the most common type in both hemifaces. There was no significant relationship between the course of facial artery and age (P > .05). Asymmetrical course of facial artery was more common in females (54.3%). In both genders, type A was the type with highest symmetry detected.

CONCLUSIONS

Nasolabial fold is one of the important facial regions for filler injection. To prevent vascular injection, course of facial artery should be identified within the nasolabial fold. Type A was the most common type in both hemifaces and genders. Although the rates were close to each other, asymmetry in the course of the facial artery was observed in most of the patients. Ultrasonographic examination which is non-invasive and non-ionizing imaging method can be performed carefully before filler injection to determine vascular tissues.

Application of 3-Dimensional Technology for Evaluating Muscular Type and Muscle-Fat Pad Mixed-Type Nasolabial Folds With Botulinum Toxin-A Treatment

BACKGROUND

Botulinum toxin-A (BTX-A) is used in the treatment of nasolabial folds (NLFs). However, lighting and clinician subjectivity play a major role in evaluating the efficacy of this treatment.

OBJECTIVES

By applying 3-dimensional (3D) technology, this study aimed to quantitatively evaluate the effects of BTX-A injection on muscular (M) and muscle-fat pad mixed-type (MF) NLFs.

METHODS

BTX-A was injected into bilateral marked points on the NLFs, where the levator labii alaeque nasi, zygomaticus minor, and zygomaticus major pull the skin to form the NLF (2 U at each injection site). Pretreatment and posttreatment 3D facial images were captured with static and laughing expressions. The curvature, width, depth, and lateral fat volume of the NLFs were measured to compare the therapeutic efficacy for type M and MF NLFs.

RESULTS

Thirty-nine patients with type M and 37 with type MF NLFs completed the follow-up data. In these patients, the curvature, width, and depth of the NLF showed a significant reduction at 1 month and gradually recovered at 3 and 6 months after treatment, with more significant improvement when laughing than when static. Variations compared to the pretreatment values of type MF were greater than those of type M at each time point. The lateral fat volume of the type MF NLF was significantly reduced (P < .05).

CONCLUSIONS

3D technology can quantitatively evaluate the effects BTX-A injection for treating type M and type MF NLFs. BTX-A is more effective on type MF than on type M NLFs.

LEVEL OF EVIDENCE: 4

New Insights into the Three-Dimensional Anatomy of the Facial Mimetic Muscles Related to the Nasolabial Fold: An Iodine Staining Technique Based on Nano-computed Tomography

PURPOSE

This study aimed to introduce a novel approach to study the facial mimetic muscles (FMMs) in relation to the nasolabial fold (NLF) and realize the visualization of complex three-dimensional (3D) structures and spatial relationships of the FMMs.

MATERIALS AND METHODS

Nano-computed tomography (nano-CT) and iodine staining techniques were used to obtain the two-dimensional (2D) radiographs of the FMMs. Materialise Mimics software was then used to reconstruct the 3D model of the FMMs.

RESULTS

The zygomaticus major muscle (ZMM) was divided into trunk fibers and branch fibers. The trunk fibers of the ZMM were subdivided into branch fibers layer-by-layer. Adipose tissue in the cheek was not a mass of unorganized fat. It was separated and fixed by branch fibers. Moreover, the trunk fibers of the ZMM were directly connected to the levator anguli oris (LAO), not the skin. On the contrary, the ZMM was connected to the skin by its subdivided branch fibers indirectly. The muscle fibers in the modiolus were organized, rather than disorganized. In other words, the terminal of the trunk fibers of the ZMM was located in the LAO. Moreover, the terminal of the trunk fibers of the LAO was located at the terminal of the trunk fibers of the musculus depressor anguli oris at the corner of the mouth. Furthermore, the levator labii superioris alaeque nasi was not directly connected to the orbicularis oris muscle. It was connected to the combination of the LLS and the rhinaeus.

CONCLUSIONS

Although nano-CT has many disadvantages, it enabled the 3D anatomical study of the FMMs in relation to the NLF when combined with iodine staining. We imported the 2D images obtained by nano-CT scanning into the Mimics software, successfully reconstructed the FMMs, and finally obtained images of complex 3D structures of the FMMs. The shapes, positions, and 3D spatial relationships of the FMMs were clearly visualized. The novel insights into the 3D anatomy of the FMMs may help understand the formation of the NLF. Finally, the results of this study may help improve the rejuvenation surgery of the NLF soon.

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.

Using three-dimensional average facial meshes to determine nasolabial soft tissue deformity in adult UCLP patients

BACKGROUND AND PURPOSE

There is limited literature discussing the residual nasolabial deformity of adult patients prior to undergoing orthognathic surgery. The purpose of this study is to determine the site and severity of the residual nasolabial soft tissue deformity between adult unilateral cleft lip and palate (UCLP) patients and a non-cleft reference group, prior to orthognathic surgery.

MATERIAL AND METHODS

Sixteen adult male UCLP patients, who all received primary lip and palate surgery according to a standardised Hong Kong protocol were recruited for this study. Facial images of each individual were captured using three-dimensional (3D) stereophotogrammetry and compared to a previous published Hong Kong non-cleft reference group of 48 male adults. Using two-sample t-tests differences in linear and angular measurements and asymmetry scores were evaluated between the two groups. In addition a "conformed" average UCLP facial template was superimposed and compared to conformed average non-cleft reference group facial template. Reproducibility of the measurements were assessed using Students paired t-tests and coefficients of reliability.

MAIN FINDINGS

Significant differences in linear and angular measurements and asymmetry scores were observed between the two groups (p < 0.05). Adult UCLP patients showed significantly narrower nostril floor widths, longer columella length on the unaffected side, a wider nose, shorter cutaneous lip height, shorter upper lip length and shorter philtrum length. Prior to orthognathic surgery adult UCLP patients showed significantly more facial asymmetry. Superimposition of the average facial meshes clearly showed the site and severity of the deficiency in the x, y and z-directions.

CONCLUSIONS

Many of the nasolabial characteristics reported to be present in children following primary UCLP repair continue into adulthood. The detrimental soft tissue effects of orthognathic surgery for UCLP patients may be different to non-cleft individuals; and as such the site and severity of the residual deformity should be assessed prior to surgery.

Quantitative and perceived visual changes of the nasolabial fold following orthodontic retraction of lip protrusion

OBJECTIVES

The objectives of this study were to evaluate the quantitative and perceived visual changes of the nasolabial fold (NLF) after maximum retraction in adults and to determine its contributing factors.

MATERIALS AND METHODS

A total of 39 adult women's cone-beam computed tomography images were collected retrospectively and divided into the retraction group (age 26.9 ± 8.80) that underwent maximum retraction following 4 premolar extraction and the control group (age 24.6 ± 5.36) with minor changes of the incisors. Three-dimensional morphologic changes of hard and soft tissue including NLF were measured by pre- and posttreatment cone-beam computed tomography. In addition, perceived visual change of the NLF was monitored using the modified Global Aesthetic Improvement Scale. The influence of age, initial severity of NLF, and initial soft tissue thickness was evaluated.

RESULTS

Anterior retraction induced significant changes of the facial soft tissue including the lips, perioral, and the NLF when compared with the controls ( P < .01). Perceived visual changes of the NLF was noted only in women younger than age 30 ( P < .05), with the odds ratio (95% confidence interval) of 2.44 (1.3461-4.4226), indicating greater possibility for improvement of NLF esthetics in young women of the retraction group when compared with the controls.

CONCLUSIONS

Orthodontic retraction induced quantitative and perceived visual changes of the NLF. For adult women younger than age 30, the appearance of the NLF improved after maximum retraction despite the greater posterior change of the NLF.

Managing the Difficult Soft Tissue Envelope in Facial and Rhinoplasty Surgery

BACKGROUND

The nasal soft tissue envelope affects the final rhinoplasty result, and can limit the expected improvement. Currently, no dependable and objective test exists to measure the thickness of the nasal skin and underlying soft tissue.

OBJECTIVES

This paper presents a simple, yet reliable method to determine the thickness of the soft tissue envelope. An algorithm is presented for treatment of the dermis and/or soft tissue apart from surgery of the underlying osseocartilaginous structures.

METHODS

Seventy-five patients presenting for primary rhinoplasty underwent visual and ultrasound assessment of their nasal soft tissue envelope. At preoperative evaluation, the Obagi "skin pinch test" was used to assess the thickness of the nasolabial fold and whether or not the skin was oily. Patients were classified based on the pinch thickness. At time of surgery prior to injection of local anesthesia, ultrasonic assessment was done at the nasolabial fold, keystone junction, supratip, and tip to measure the thickness of the nasal dermis and underlying soft tissue.

RESULTS

Patients determined to have thin, normal, and thick skin by the "skin pinch test" were found to have a nasolabial fold dermal thickness with an average of 0.7 mm (0.4-1.2 mm), 1.1 mm (0.8-1.8 mm), and 1.4 mm (0.7-2.0 mm). Patients determined to have thin, normal, and thick skin were found to have a dermal thickness at the keystone junction with an average of 0.3 mm (0.2-0.4 mm), 0.5 mm (0.3-1.1 mm), and 0.9 mm (0.6-1.2 mm), respectively. This difference in thickness also translated to the supratip and tip areas measured. However, all areas were also affected by the oiliness of the skin. Soft tissue thickness (SMAS and muscle) underlying the dermis was variable. Patients of non-Caucasian background were more likely to have a thicker soft tissue layer.

CONCLUSIONS

The "skin pinch test" is an easy and reliable way for the surgeon to evaluate the thickness of the nasal soft tissue envelope. The rhinoplasty surgeon can make decisions pre- and postoperatively to treat patients with difficult soft tissue envelopes. LEVEL OF EVIDENCE 4.