Revitalizing the lower face: Therapeutic insights and an innovative treatment guideline for jowl rejuvenation

The intricate mechanisms of jowl formation, which ultimately lead to loss of lower jaw definition, skin laxity, and localized fat accumulation, involve interrelated factors such as skin aging, fat redistribution, muscle dynamics, and loss of support.

by the loss of definition of the lower jaw, which is often associated with the appearance of localized fat and sagging of the overlying skin.The word is derived from the Middle English cholle, meaning "a fullness and looseness of the flesh of the lower cheek and jaw," and is used clinically in the absence of an appropriate anatomical term. 1 Jowl formation involves several aspects of facial aging that can be identified individually but are often interrelated: skin laxity, fat redistribution, loss of support and consequent ptosis, and changes in muscle dynamics in the lower third of the face and proximal neck.
Skin laxity associated with aging is exacerbated by the redistribution of subcutaneous adipose tissue, which contributes to the perception of sagging and some of the anatomical changes observed in this process. 2In addition, the disproportion between the different fat compartments of the lower face can create the illusion that the wrinkles are more pronounced, creating a "pseudoptosis." 3 The platysma is loosely attached to the jawbone between the mandibular ligament and the masseter, 4 making it susceptible to inferior displacement due to lack of support.Bone remodeling and deflation of the soft tissues, even in distant structures such as the temples, can both lead to this change in jawline position. 5,6derstanding the exact mechanism involved is still a work in progress.Whatever the true cause may be, the weakening of the mandibular septum (which is responsible for holding the skin and superficial fat compartments in place) causes the jowls to sag and become more pronounced and flaccid. 7e role played by the musculature in the lower face is also dynamic and should be considered, as it may contribute to the deterioration of mandibular definition by pulling the soft tissues inferiorly.
The pars modiolar of the platysma muscle (formed by fibers of the superior platysma that are posterolateral to the DAO) is particularly involved in jowling.The contraction of these fibers pulls the corner of the mouth laterally, creating vertical lines and wrinkles caudal to the DAO, weakening the support of the mandibular line and affecting the facial contour. 8Botulinum toxin is the most frequently performed aesthetic treatment 9 worldwide and can also help restore the jawline by inhibiting the downward traction of the platysma muscle on the lower face. 8nsidering the multiplicity of causes that can often coexist in the same patient, treatment should involve synergistic approaches.
This can be a challenging scenario.Therefore, a structured guideline can help dermatologists program the ideal treatment protocol for each individual case by following diagnostic steps that lead to suggestions of corresponding therapies (Figure 1).
Both surgical and non-surgical approaches should be considered, and decision-making depends mainly on the degree of facial sagging, the patient's preferences, expectations, and financial resources, as well as contraindications and downtime. 10 Chemical peels improve skin texture by stimulating collagen production and cell renewal, thereby promoting firmness and elasticity. 11Energy-based devices such as micro-and macro-focused ultrasound, lasers, and radiofrequency microneedling act on the superficial and/or deep layers, creating microlesions that induce a regenerative response, stimulating collagen and elastin production, consequently improving sagging. 12,13e so-called collagen stimulators, such as calcium hydroxylapatite and poly-l-lactic acid, can improve skin quality and restore volume, depending on the dose injected per treated area. 14,15This may offer a two-in-one solution when the targeted soft tissue deflation is primarily in the subcutaneous layer.
During the second step of the proposed guideline, which involves assessing fat distribution, the diagnosis focuses on observing atrophy or increased volume in the jowl region.The trick is to identify whether there is a lack or excess of volume.If there is excessive fat in the jowl, reducing this volume should be the first choice.
Aside from liposuction, minimally invasive lipolytic injectables such as deoxycholic acid can help reduce accumulated subcutaneous fat. 16However, although some successful cases have been published, injection site-related complications such as alopecia and marginal mandibular nerve paresis have been reported. 17Microfocused ultrasound applied to deeper facial layers can also stimulate muscle/ aponeurosis retraction, reduce specific fat pad volumes, and thus contribute to a more defined contour. 12Studies with laboratory animals have demonstrated that smooth polydioxanone threads may reduce the thickness of the fat layer by denaturing fat cells. 18The use of an intercross pattern may aid in the treatment of adipose hypertrophy of the jowl, but further data in humans are necessary.However, in most patients, the fat pad that forms the jowl is normotrophic.It may appear to be relatively hypertrophied due to deflation in the masseteric region and/or the labiomandibular fat pad.
Therefore, the therapeutic strategy should be directed to the use of fillers such as hyaluronic acid to restore the lost volume of the adjacent fat pads, although this may seem counterintuitive at first.A third stage is aimed at identifying the deformation of the mandibular arc and what are its underlying processes.If there is bone deformation in the mandible, the suggested treatment is to restore the shape and contour of the mandibular arc, easing the transition of the jowl.Loss of underlying soft tissue support and fullness in the mid-or upper face can be responsible for such soft tissue descent, 19 and restructuring might be necessary to address this issue.
A hyaluronic acid filler injection can serve as a volumizing and/ or lifting agent.It can significantly reposition the lower face when injected at key points. 20The choice of product and its rheological properties should depend on the target area/layer and the practitioner's expertise.Polydioxanone barbed sutures are an alternative approach to support sagging tissue by anchoring subcutaneous structures and providing a light traction force that mechanically lifts skin and fat pads while promoting collagen deposition. 12However, excess skin may require referral to plastic surgery.
The fourth and final step involves assessing changes in the muscular dynamics of the lower third of the face, as evidenced by contraction and increased platysmal tone.The platysma muscle pulls down the modiolus, the corners of the mouth, and the lower third of the face.Botulinum toxin injections into the platysma muscle can lift the lower third of the face and improve the contour of the jawline, resulting in a more aesthetically pleasing appearance by lifting drooping corners of the mouth and jowls. 21Analyzing dynamic lines under maximum contraction allows the injector to infer the specific muscles' role in generating dynamic lines and plan customized injection patterns. 22r guideline provides a structured approach to the causes of jowl formation that may assist physicians in making rational decisions.However, it is important to acknowledge that it may oversimplify skin conditions and therapeutic options.Additionally, the effectiveness of treatments can vary based on factors such as the severity of the condition, the patient's response, and any contraindications.To ensure precise decision-making that is aligned with the patient's expectations, it is crucial to consider each individual's unique characteristics and conduct a thorough assessment.
To comprehend the "jowl" phenomenon, it is essential to understand the complexity of facial anatomy and the effects of aging on facial dynamics.This study presents non-surgical and minimally invasive therapeutic approaches to meet patients' individual needs and a structured guideline that provides a practical framework for medical professionals to consider treatments based on observed characteristics.A thorough understanding of facial anatomy and a precise application of therapeutic interventions not only contribute to improved aesthetic outcomes, but also to patient satisfaction. 23

E TH I C S S TATEM ENT
Authors declare human ethics approval was not needed for this study.

PH OTO CO N S ENT S TATEM ENT
The are no photos or patient personal information in this article.
Surgical approaches to jowl correction seek more immediate and lasting results.A full facelift, neck lift (cervicoplasty), and liposuction are some of the surgical options available for jowl reduction.The focus of our guideline is on minimally invasive techniques, as it is intended for use by dermatologists.The therapeutic guideline suggests a series of yes/no questions that focus initially on identifying which of the four main aging processes involved in jowl formation are present in that particular patient: sagging skin, fat redistribution, static jawline deformation, and dynamic jawline deformation caused by the muscles.This leads to the following questions, which are aimed at identifying the cause of the previously identified component of the jowl.The subsequent answers will then hint at the choice of treatment.The initial step involves a thorough evaluation of skin conditions and identifying ptosis of the superficial facial layers.A myriad of treatments can counteract skin aging, and a key point here is to assess whether or not there is deflation of subcutaneous adipose tissue.If skin laxity is accompanied by a loss of subcutaneous volume, collagen stimulators are the recommended therapeutic choice to restore skin elasticity while also replenishing the affected areas.If there is no noticeable loss of subcutaneous fat, the focus should be on improving skin texture through the use of peels, skin boosters, and/or energy-based devices.F I G U R E 1 Timeline suggestion for introducing different aesthetic procedures.