Hyaluronic Acid in the Mandibular Ramus: Indication and Risks

The mandibular ramus and angle are the points that give the lower third of the face its lateral frame. When they are lost, through volume loss, bone resorption, laxity or body type, patients describe the face as "round", "droopy" or "without contour". That is why the jawline is one of the most frequent concerns in the office, and one of those that most demand attention to the overall plan.

This page is a review of anatomy, indication and risks for the orofacial harmonization (HOF) professional. It is not a step-by-step technique. Product, volume and approach are at the discretion of the licensed professional, after assessment, according to the rules of their professional board and the product's instructions for use.

What anatomy is at play?

The mandible has a horizontal body and a vertical ramus, joined at the mandibular angle. The jawline is the visible contour of this structure. Over the ramus lies the masseter muscle, with the parotid gland over part of its surface and the premasseteric space in front. The masseteric ligament fixes the skin to the muscle and takes part in forming the jowl when tissue descends.

The main points of attention:

• The marginal mandibular branch, a branch of the facial nerve, which descends toward the lower lip (see marginal mandibular branch).
• The facial artery and the transverse facial artery, which supply the area (see facial artery and transverse facial artery).
• The parotid and its duct, which should not be targeted by the injection.
• The masseter, whose hypertrophy completely changes how the area reads (see masseter hypertrophy: differential diagnosis).

When is ramus filling considered?

Among the most cited situations:

• A poorly defined mandibular angle, with a smooth transition between ramus and body.
• Loss of lateral jaw volume in more mature faces (see aging of the chin and mandible).
• A contour plan that combines chin, jaw and midface (see lower third laxity: assessment).
• A search for more definition, in patients who want a more pronounced contour, sometimes due to masculinizing or feminizing references (see facial masculinization with injectables).

Hyaluronic acid is not the only option for the contour. There are products of a different nature, such as calcium hydroxyapatite (see hydroxyapatite in the jawline), as well as PDO threads in the jaw and jowl. The choice depends on assessment, expectations and the professional's preference, always according to the instructions for use.

What are the most relevant risks?

See also nerve injury with injectables, expanding hematoma of the face and transient facial paralysis after anesthesia.

How to assess the patient?

Bruxism is relevant, because masseter hypertrophy and toxin may come into the plan (see botulinum toxin in the masseter and botulinum toxin for bruxism). Previous orthognathic surgery changes the anatomy, as in harmonization after orthognathic surgery, and orthodontics influences the profile (see orthodontics and facial profile in HOF).

How to think of the ramus within the whole face?

The jawline only works in harmony with the chin, the midface and the proportions of the face. A very pronounced angle on a face with a recessed chin or marked double chin tends to look out of proportion. See the overview in retrognathic profile: assessment, double chin: assessment and square face: assessment.

What Harmy shows

In Harmy, the Jawline point lets you set the ml and the intensity (Subtle, Moderate or Pronounced) and generate an illustrative projection from a front-facing photo. The app does not separate ramus, angle and body, and the front-facing photo limits how the angle can be read. The projection is useful for talking about proportion, always as an illustrative simulation, not a promise of results. See the Jawline area and the mandibular filler procedure. In the app's "Full harmonization" shortcut, the jaw is set at 2 ml, Moderate intensity.

What to do if something goes off plan?

For irregularity or excess volume, hyaluronidase is an option when indicated (see dissolving filler: criteria for indication). For volume control, see excess volume after filler. Record product, lot, volume and course in the patient record (see traceability of injectables) and schedule follow-up according to clinical follow-up after HOF.

How to guide the patient in the first days?

The ramus area is more prone to swelling and bruising than people imagine, because it is well vascularized and the patient handles it when chewing, talking and sleeping. Give instructions in writing: avoid massage and pressure on the area unless the professional says otherwise, sleep on the back in the first days, avoid intense exercise and excessive heat, and come back if there is asymmetry of the smile, increasing pain, warmth or local redness.

Also explain that the contour settles over weeks and that the result is assessed at follow-up, with comparable photos. Schedule the review and make the contact channel for warning signs clear. A patient who knows what is expected (swelling, mild discomfort when chewing) and what is not (intense pain, color change, difficulty moving the lower lip) seeks help sooner, which changes how a complication unfolds.

In summary

The jaw ramus offers high-impact aesthetics and demanding anatomy: nerve, vessels, muscle and gland share a small space. A safe indication starts by separating the cause of the lost contour, continues with conservative volume and preparation for a complication, and ends with follow-up and records.