Chin projection and the mewing myth: what actually moves your profile

"Weak chin" is one of the most common self-diagnoses in aesthetic self-improvement content, and one of the least precisely defined. It gets assigned by eye from a selfie, then treated with everything from filler to jaw exercises to hours a day of a specific tongue posture. The clinical version of the question is narrower and answerable: how far forward does the chin sit relative to the rest of the profile, and what actually moves that number.

Definition

Chin projection is read on a profile view using Ricketts' esthetic line, or E-line, first described in his 1957 Angle Orthodontist paper on facial pattern and growth prediction. The E-line runs from the tip of the nose to the soft-tissue pogonion, the most forward point of the chin. Lip position is then read against that line rather than against the chin directly: in Ricketts' adult norms, the upper lip sits about 4mm behind the line and the lower lip about 2mm behind it. A chin that sits well behind the line, pulling the whole lower face back from that reference, is what "weak chin" is actually describing in cephalometric terms.

Legan and Burstone's 1980 soft-tissue cephalometric analysis, published in the Journal of Oral Surgery, extended this into a fuller set of profile norms used in orthognathic planning, including facial convexity angle and mentolabial sulcus depth, both of which move together with chin projection rather than in isolation.

Why the chin is a skeletal question, not a posture question

Soft-tissue pogonion sits directly over the bony chin, the mandibular symphysis. Its forward position is set almost entirely by the underlying bone: how far forward the mandible grew during development, plus a thin, largely fixed layer of soft tissue on top. Submental fat and skin laxity affect how defined the area under the chin looks, but they do not move the point where the chin itself projects forward.

This is the reason "mewing," sustained tongue-to-palate posture popularized as a jaw and chin reshaping method, does not do what it is marketed to do in an adult. Facial bones remodel in response to sustained mechanical load during growth, which is the real mechanism behind orthodontic functional appliances used in children and adolescents, applied under professional supervision with far more force than resting tongue pressure and monitored against open growth plates. Once the craniofacial sutures and the mandibular symphysis fuse, generally by the late teens to early twenties, that remodeling capacity is gone. Tongue posture from that point forward can affect resting jaw position and, over years, minor dental and soft-tissue changes, but it does not advance the bony chin.

What actually changes projection at each stage

• Genioplasty (chin bone surgery) or a chin implant: the only interventions that move the actual bony pogonion forward in an adult. Both are surgical.
• Chin filler: adds soft-tissue volume over the existing bone, shifting the visual point of pogonion forward without touching the skeleton underneath. Reversible with hyaluronidase.
• Submental fat reduction (diet, or a procedure like deoxycholic acid injection or liposuction): does not move projection, but improves definition under an already-projected chin by removing tissue that was obscuring the jawline.
• Posture and mewing: no peer-reviewed evidence supports skeletal remodeling of the adult chin from tongue posture alone. It is not the same mechanism as a supervised orthodontic appliance in a growing patient.

How Facet measures it

Facet's jawline module locates the nasal tip, upper and lower lip, and soft-tissue pogonion from a profile photo, constructs the Ricketts E-line, and reports both lips' distance from it in millimeters against the adult norms above. Because the E-line requires a true side view, a frontal-only scan reports jaw width to face width and defers chin projection, flagged in the module, until a profile photo is supplied.

A full example of how the jawline module reports this, alongside the other nine, is posted at [/sample-report](/sample-report). The citation list behind every threshold, including this one, is at [/methodology](/methodology).