Using injectable fillers for chin and jawline rejuvenation

Abstract

Objective

As the population ages, facial plastic providers must remain aware of the treatments to prevent and reverse the external signs of aging. In the mandibular region, skin laxity and soft tissue sagging in the jawline may lead to jowling and chin ptosis along with reduced chin projection. While surgical procedures, including chin implantation, may be performed, nonsurgical procedures are becoming increasingly popular due to their temporary, noninvasive, yet effective methods. This review covers the use of hyaluronic acid, calcium hydroxylapatite, poly‐l‐lactic acid, and polymethyl methacrylate in the jawline.

Methods

PubMed was searched for data on the mechanism of action, pertinent anatomy, indications, contraindications, technique, and evidence supporting the safety and efficacy of the fillers.

Results

There are a wide variety of fillers available for use in the lower face with unique characteristics and application methods. While the advantages of injectable fillers include relatively affordable cost, minimal patient discomfort, and limited recovery times, taking measures to prevent short‐ and long‐term complications is necessary for optimal results.

Conclusions

Understanding the benefits and limitations of injectable fillers in the jawline can help providers appropriately counsel and treat patients.

A variety of injectable fillers are available for nonsurgical jawline rejuvenation in the aging face. Major advantages include relatively affordable cost, minimal downtime for results, reduced patient pain, decreased recovery times, and absence of surgical incisions. The patient should be counseled on short‐ and long‐term complications, as well as the limitations of injectable fillers.

Key points

• Hyaluronic acid, calcium hydroxylapatite, poly‐l‐lactic acid, and polymethyl methacrylate are among the most popular dermal fillers used for augmentation of the lower face.

• This review provides a comprehensive overview and highlights the mechanism of action, pertinent anatomy, indications, contraindications, technique, and evidence supporting the safety and efficacy of fillers.

INTRODUCTION

Interventions to prevent and reverse the inevitable effects of aging have risen in popularity over the course of the past few decades. From 2015 to 2019, the total number of injectables increased by 17.8%, with Americans spending more than $1.6 billion dollars in 2019 alone. ¹ Using the 2010 U.S. Census Bureau, Broer et al. ² estimated that approximately 3.8 million aesthetic procedures will be performed by 2030, a staggering increase from the 1.6 million aesthetic procedures performed in 2012. As the population continues to age, we will see an increased interest in patients desiring to slow the aging process, utilizing both surgical and nonsurgical interventions.

Intrinsic and extrinsic factors contribute to the aging process. As we age, the layers of the skin thin, leading to delayed wound healing, increased skin fragility, and reduced turnover. ³ , ⁴ , ⁵ , ⁶ Weakening of the dermal‐epidermal junction is associated with reduced expression of collagen and other scaffolding proteins that provide structural and volume support. ⁷ These intrinsic processes are affected by external factors such as radiation, general health, tobacco and alcohol use, and gravity. ⁸ Taken together, the intrinsic and extrinsic factors contributing to the aging process lead to loss of skin elasticity, descent of soft tissue, muscular atrophy, and bony loss. In the lower face, excess skin can lead to jowling, while bony loss along the mandible leads to reduced chin projection. ⁹ Chin ptosis, commonly known as witch's chin, results from sagging of soft tissues resulting in a prominent submental crease. ¹⁰

Surgical and nonsurgical procedures are available to restore a youthful appearance to the lower face. Alloplastic chin implantation is the most common surgical procedure for chin retraction and is often performed as an adjunct to rhytidectomy. ¹¹ , ¹² Nonsurgical procedures for mandibular rejuvenation include injectable fillers, autologous fat grafting, and botulinum, and another option for patients seeking treatment for the aging chin. Dermal fillers offer a temporary, noninvasive, and effective method to improve jawline contour, and there are numerous fillers available for use with varying levels of permanency, viscosity (G″), elasticity (G′), and longevity.

Reducing the effects of aging on the mandible and chin is a key component of facial rejuvenation. The objective of this review is to focus on nonsurgical procedures for mandibular rejuvenation, specifically the mechanism of action, indication, technique, and data supporting the safety and efficacy of the most commonly used fillers. Understanding the benefits and limitations of injectable fillers in jawline rejuvenation can help providers determine the most appropriate option for optimal and long‐lasting aesthetic outcomes in their patients.

INJECTABLE FILLERS

The definition of the mandibular angle and chin area is one of the key contributing factors to a proportional and youthful face. In particular, a well‐contoured jawline is desirable in both men and women. During the aging process, the mandible recedes anteriorly and inferiorly, increasing the mandibular angle, while the chin becomes more anterior and shorter. ¹³ Atrophy of mandibular fat and dehiscence of the mandibular septum results in the formation of jowls, or excess skin beneath the mandible. Nonsurgical rejuvenation in the lower third of the face thus targets these specific areas to restore a youthful appearance. Ideal indications for hyaluronic acid (HA) fillers include mild to moderate loss of facial contour, volume, and laxity; more severe cases may require surgical intervention. ¹⁴

Targets for filler injection sites include the melomental folds (i.e., marionette lines), mental crease, chin apex, prejowl area, and mandibular body and angle. An understanding of vascular anatomy is essential to avoid vascular complications with all lower‐face rejuvenation procedures. Melomental folds are targeted using a linear subcutaneous retrograde technique to deliver the bulk of the volume to the top third of the fold while staying medial to the crease. ¹⁵ Reducing the depth of the mental crease is achieved similarly, although an anterograde injection approach may be used. Chin projection should approximate as far as the lower lip, and filler should be placed at two to three sites in the anterior portion to achieve this goal. ¹⁶ While filling the prejowl region is important to restore the jawline, the injector must avoid overfilling, which may widen the chin. This may be accomplished through a deep subcutaneous injection with a fanning technique for equal distribution. Finally, augmentation in the mandibular area allows for a more defined jawline and can be achieved with a superficial subcutaneous injection over the body, and a supraperiosteal injection over the angle.

HA

HA is the most commonly used soft‐tissue filler. It is an injectable, large, nonsulfated glycosaminoglycan found in the extracellular matrix of connective tissue, synovial fluid, and other tissues. It is composed of polymeric disaccharides, and forms hydrogen bonds in aqueous solutions. Thus HA retains water and is structurally stable. ¹⁷ It is thought that 1 g of HA can bind up to 6 L of water. ¹⁸ In the native human body, HA has a variety of functions ranging from shock absorption in joints to tissue healing. ¹⁹ HA has minimal immunogenicity, making it a favorable option for many patients seeking nonsurgical treatment for facial lines and wrinkles.

There are a variety of HA‐based fillers available that have predominantly been studied in the treatment of nasolabial folds, these include Restylane (Galderma), Juvéderm (Allergan Inc.), and Vycross (Allergan Inc.) (Table 1). In an 18‐month open study using HA filler (Galderma SA), at least a 1‐grade improvement in the 4‐point volume loss scale was observed for the chin (77.8%) and jawline (43.1%). ²⁰ At the final follow‐up, 95.0% of all patients were satisfied with their aesthetic outcome. Other reports of success in improving the anterior, transverse, and vertical dimensions of the chin have been anecdotally cited. ²¹ As with all filler injections, complications such as erythema, edema, bruising, delayed nodules, granuloma, infection, and hematomas may occur. As the skin overlying the chin is thicker compared to the more posterior portions of the face, contour irregularity is not commonly seen.

Table 1.

Comparison of filler material.

Characteristics	Hyaluronic acid	CaHa	PLLA	PMMA
Origin	Natural extracellular matrix from body joints, skin	Human bone and teeth	Synthetic polymer	Synthetic polymer
Mechanism of action	Increases water absorption and skin volume	Stimulation of collagen formation	Dual action of increasing volume followed by stimulation of collagen formation	Dual action of increasing volume followed by stimulation of collagen formation
Immunogenicity	Minimal	Minimal	Minimal	Moderate
Allergy testing	Not required	Not required	Not required	Required
Permanency	Semi‐permanent	Semi‐permanent	Semi‐permanent	Permanent
FDA approved	Juvéderm Juvéderm XC, VOLUMA, VOLBELLA, VOLLURE Restylane Restylane, Restylane Silk, Restylane Lyft, Restylane Refyne, Restylane Defyne, Belotero Balance	Radiesse	Sculptra	Arteplast, Artecoll, Artefill, Bellafill
Time to take effect	Immediate	Immediate	Delayed	Delayed
Duration of effect	3–12 months	9–12 months	Up to 2 years	Up to 5+ years
Reversible	Yes	No	No	No
Comments	Soft, gel‐like, extremely versatile	Thicker, white‐colored suspension so must take care with placement	Requires multiple treatment sessions to reach desired results, but mimics fat transfer	Results may be permanent

Abbreviations: CaHa, calcium hydroxylapatite; PLLA, poly‐l‐lactic acid; PMMA, Polymethyl methacrylate.

Calcium hydroxylapatite (CaHa)

Commercially available as Radiesse (Merz Pharmaceuticals GmbH), CaHa is a synthetic, biocompatible, biodegradable soft tissue filler that is identical in composition to human bone and teeth. ²² CaHa is a semi‐permanent filler with a unique time‐delayed dual function. When first injected, the filler acts as a volume expander. Over time CaHa microspheres serve as a scaffold for newly formed collagen, as the particles are able to encourage fibroblastic growth while preventing osseointegration and calcification, thus promoting the ingrowth of collagen. ²³ , ²⁴ , ²⁵ As CaHa microspheres physiologically mimic the structure and metabolism of bone, these fillers demonstrate an excellent safety profile without any evidence of inflammation, body reaction, or granuloma formation. ²⁶ The advantage, therefore, is that patients do not have to receive allergy testing before use.

Radiesse is manufactured in prefilled 0.3, 0.8, or 1.5 ml syringes with a gel composed of 30% CaHa microspheres suspended in 70% aqueous solution. Injection volumes and techniques vary with the location of the site and desired effect, however, administration of CaHa is similar to the methods described above for HA. ²⁷ Factors favoring the use of CaHa over HA include thick skin at the site (i.e., near the chin region) and the goal of bony structure definition, as CaHa's incompressible characteristic allows for structural augmentation compared to the more elastic HA filler. ²⁸ It remains important, however, to not overcorrect a contour deficiency, and small volumes (0.05–0.1 ml) are recommended per injection site. After placement, tissue should be massaged to ensure optimal contour. Duration of effect has been reported to last at least 1 year in most patients. ²⁹

To date, most trials evaluating the long‐term safety of CaHA were in patients presenting with nasolabial fold defects. There have been limited studies assessing the efficacy, safety, and patient satisfaction of CaHa in the mandibular region. One consensus statement study in 2013 described the most appropriate techniques and injection protocols to restore the aging upper and lower jawline. ³⁰ An observational study of 35 subjects receiving CaHa for jawline rejuvenation found improvement from moderate/severe sagging at baseline to mild sagging up to 1 year after injection. ³¹ Both physician and patient satisfaction were high, with minimal adverse effects noted. A similar significant restoration of volume and appearance has been reported with CaHa filler with integral lidocaine (CaHa+) in 20 subjects. ³² Finally, a combination of HA with CaHa has also been studied with successful results, as it is thought that HA can augment early unexpected volume loss from CaHa. ³³

Poly‐L‐lactic acid (PLLA)

PLLA is a semi‐permanent, biodegradable, biocompatible, synthetic polymer with a variety of medical uses. Unlike other fillers, PLLA's mechanism of action is delayed. After placement, PLLA particles stimulate an inflammatory response, leading to production of lactic acid and its byproducts. ³⁴ The host tissue reacts by inducing growth of collagen, connective tissue, and inflammatory cells, eventually leading to deposition of type I collagen around the foreign body reaction. ³⁵ Despite the immunologic response, the foreign body reaction is completely biocompatible, with postinjection biopsies demonstrating no residual filler material or fibrosis. ³⁶ The effects of tissue expansion have been noted for up to 2 years, although the duration of this effect is best appreciated after multiple treatments across 1–2 months.

Sculptra (Galderma) is currently approved for facial lipoatrophy associated with human immunodeficiency virus (HIV) and correction of nasolabial folds. The filler comes in a glass vial with a sterile freeze‐dried powder that must be reconstituted for at least 2 h using sterile water with lidocaine for anesthesia. ³⁷ When approaching the lateral mandible and mandibular angle, injections should be in the superficial subcutaneous fat, whereas augmentation to the menton and prejowl sulcus are typically supraperiosteal. ²⁷ Care should be taken to avoid directly injecting into the muscle fibers of the oral commissure or depressor anguli oris muscle, which may lead to nodule formation. ³⁸ Patients should be counseled that full volumetric correction may only be achieved after multiple sessions. Overfilling the defect area may lead to an increased likelihood of irregular contouring and nodularity. After injection, patients are recommended to follow the “rule of 5 s”, where massage should be applied for 5 min, 5 times a day, for 5 days. ³⁹

The safety profile of Sculptra is well reported within the literature, ranging from short‐term events such as erythema, ecchymosis, and edema to long‐term complications including subcutaneous nodules and granulomas. ⁴⁰ Increasing the dilution of sterile water in the injection was associated with a reduction in the incidence of adverse events. Literature on the use of injectable PLLA for lower‐face volumetric correction is sparse. Based on a single center's experience of over 2500 patients, PLLA was found to be suitable for a wide variety of facial contour defects. ⁴¹ In one patient presenting with mid‐ and lower face volume loss despite prior treatments of collagen and HA, a series of four injections of Sculptra over 4 months demonstrated significant enhancement persisting up to 18 months. A retrospective case series of 100 patients treated with PLLA for a variety of facial wrinkles showed long‐lasting (up to 5 years) aesthetic results, with one patient developing papules, resolving with intralesional steroid injections. ⁴² While infrequent, serious vascular complications, including mental artery occlusion, have been reported. ⁴³ , ⁴⁴ There are no high‐quality, randomized controlled trials as of yet studying the use of PLLA injections on lower face rejuvenation.

Polymethyl methacrylate (PMMA)

PMMA is a biocompatible, permanent filler with a similar dual mechanism of action to that of Radiesse (CaHA). PMMA microspheres are suspended in bovine collagen gel, allowing for immediate volume expansion upon injection, while promoting long‐term collagenesis after resorption of gel within 1 month. ⁴⁰ Due to their small, smooth, and uniform size, PMMA microspheres resist phagocytosis and degradation by macrophages and instead encourage connective tissue and cell growth. ³⁶ Initial packaging of PMMA microspheres into the fillers Arteplast and Artecoll (Suneva Medical) in the 1990s revealed granulomas in up to 2.5% of patients within 6 to 18 months. ⁴⁵ However, newer generations of PMMA injectables (Artefill, Bellafill; Suneva Medical) have undergone a refined purification process and are FDA‐approved for treatment of facial wrinkles and correction of severe facial acne scars. Due to its bovine collagen base, hypersensitivity testing is required 4 weeks before injection, and treatment is contraindicated in any patient with a positive response.

Compared with CaHa, overcorrection with PMMA is of lesser concern as the deep‐dermal layer only allows for a certain volume of filler to be implanted. Because of this characteristic, a second injection is often necessary to add a second layer on top of the original placement. ⁴⁶ Other unique advantages of PMMA include ease of use, permanent placement, collagen formation, and long‐lasting results. Using the fanning technique to inject PMMA along the prejowl sulcus, chin, marionette lines, and mandibular region allows for a relatively equal distribution of the filler. To improve patient comfort during the procedure, using a massager while injecting has been reported to reduce the sensation of pressure around the prejowl area. ²⁷

After initial modifications to the manufacturing and purification process, adverse events associated with Bellafill are now rare. From 2007 to 2016, more than 530,000 syringes were distributed worldwide, and only 11 confirmed granulomas (0.002%) have been reported. ⁴⁷ Despite the excellent safety profile, the use of Bellafill is less popular than the other injectables, in part due to its significant granuloma formation from the prior generation, more permanent nature, and allergy skin testing. Nonetheless, PMMA remains a viable option for patients who prefer a longer‐lasting injectable filler with minimal upkeep.

DISCUSSION

The jawline is susceptible to age‐associated volume loss, resulting in chin ptosis, loss of definition, and accumulation of excess skin. Filler options are widely available to correct the cumulative effects of aging in the lower face. A thorough understanding of the advantages and limitations of injectable fillers is crucial to guide appropriate treatment and achieve optimal results.

The popularity of chin augmentation surgery has decreased with the introduction of less invasive techniques. From 2015 to 2019, The Aesthetic Society reported a nearly 17% decline in the number of chin augmentations, with a drop of 7% from 2018 to 2019 alone. ¹ Increased levels of acceptance of injectables may also play a significant role in this trend. A global survey conducted by Allergan in 2016 reported that 65% of respondents agreed that facial fillers were more socially acceptable than they were 5 years ago. ⁴⁸ Fifty‐seven percent of respondents also felt that injectable treatments could provide natural‐looking results. As more patients seek out treatment options that are also safe and effective, injectable fillers are an attractive alternative to more traditional operations.

Major advantages of injectable fillers include relatively affordable cost, little to no downtime for results, minimizing patient discomfort, and limited recovery times. The absence of surgical incisions obviates patient concerns about scarring. Another benefit of injectables is individualized treatment plans, as the provider is able to deposit material based on patient preference and goals. Volume replacement in the anterior, vertical, and transverse dimensions allows for three‐dimensional chin “shaping” in an array of contours. For example, patients desiring a more masculine appearance can opt for filler placement over the masseter, broadening the jaw. ²¹ Fillers are also generally well tolerated, and results last up to a few years, depending on the material. HA is the most‐studied injectable filler for jawline rejuvenation with a durable treatment benefit of up to 18 months. ⁴⁹ However, the majority of literature on this topic is single‐blind studies, introducing potential bias when assessing subjective improvement. ⁵⁰ , ⁵¹

All fillers are associated with short‐ and long‐term complications. Injection site reactions, including erythema, edema, bruising, pain, and discomfort, may occur. ⁵² These complications are typically mild and transient and may be reduced with the addition of lidocaine to the injection, avoidance of anticoagulants before procedure, and application of a cold compress. ⁵³ Infection risk is mitigated with sterile technique and skin preparation with antiseptic agents. ⁵⁴ Hypersensitivity reactions to foreign body material can range from mild irritation to angioedema. Antihistamines, oral corticosteroids, ibuprofen, and other immune‐modulating medications can be given to alleviate symptoms. ⁵⁵ Long‐term complications include delayed‐onset nodules and foreign‐body granulomas, which may be treated with antibiotics, hyaluronidase, and immunosuppressive agents. ⁵⁶

One feared complication is vascular compromise, which may lead to skin necrosis and vision loss. Unlike other frequently targeted areas for facial rejuvenation, there are no major neurovascular structures in the subdermal or subcutaneous planes along the jawline. ⁵⁷ Familiarity with nearby structures, including the facial artery and vein, marginal mandibular nerve, parotid gland and duct, and masseter muscle, remain important during filler injection. ⁵⁸ Should vascular infiltration occur, consensus guidelines recommend that patients receiving HA be promptly treated with hyaluronidase followed by an oral aspirin regimen. ⁵⁹ While this complication is fortunately rare, a variety of algorithms for management of this complication have been developed. ⁵⁵ , ⁶⁰ , ⁶¹

There are several limitations to injectable fillers that must be mentioned. Despite an excellent safety profile, the efficacy of fillers is limited in patients with more severe chin retrusion. Surgically placed alloplastic implants are frequently used to address horizontal (i.e., anterior) deficiencies of the chin in patients with normal vertical height. ¹⁴ Although more invasive and extensive, genioplasty is another reliable operation to address a variety of jawline issues, including chin asymmetry, prognathia, and vertical deficiency. ⁶² Compared with injectable fillers, a surgical option may be preferable for patients desiring a permanent solution without the hassle of repeat or revision treatment. A clinical comparative study by Bertossi et al. ⁶³ assessing surgical sliding genioplasty, alloplastic implant, and HA filler injectables in 345 patients demonstrated more stable long‐term results with genioplasty. In patients >50 years with reduced soft‐tissue volume, genioplasty was performed in those with more severe horizontal chin deficiency (defined as horizontal chin retrusion more than 4 mm from the true vertical line), whereas more mild deficiencies were corrected with fillers.

CONCLUSION

The chin is a key contributor to a proportional and youthful‐appearing face. A range of injectable fillers are available for nonsurgical jawline rejuvenation and offer a noninvasive, effective, and safe alternative to surgical intervention. Understanding pertinent anatomy, patient goals, proper technique, and potential complications are vital for providers to provide optimal care.

AUTHOR CONTRIBUTIONS

The authors confirm their contribution to the paper as follows: study conception and design: Oren Friedman, Ariel S. Frost; data collection: Beatrice C. Go, Ariel S. Frost; analysis and interpretation of results: Beatrice C. Go, Ariel S. Frost; draft manuscript preparation: Beatrice C. Go, Ariel S. Frost, Oren Friedman. All authors reviewed the results and approved the final version of the manuscript.

CONFLICT OF INTEREST STATEMENT

The authors declare no conflict of interest.

ETHICS STATEMENT

This article does not contain any studies involving human participants performed by any of the authors.

Go BC, Frost AS, Friedman O. Using injectable fillers for chin and jawline rejuvenation. World J Otorhinolaryngol Head Neck Surg. 2023;9:131‐137. 10.1002/wjo2.93

DATA AVAILABILITY STATEMENT

N/A.