Maxilla

The maxilla is the upper jaw. Strictly it is a pair of bones fused at the midline, and it does more structural work in the face than its name suggests: it holds the upper teeth, forms the hard palate, makes up the floor of the nasal cavity and part of the floor of each eye socket, and meets the cheekbones at the side.

Why it matters to how a face looks

Because it sits at the centre of the face, the maxilla supports a lot of what is visible: the area under the eyes, the base of the nose, the upper lip, and how the upper teeth meet the lower ones. A maxilla that sits further forward gives more support to all of those; one that sits further back gives less. That is the whole basis of the forum vocabulary of "forward growth".

What "recessed maxilla" means

On forums, "recessed maxilla" is usually a self-diagnosis made from photos: flatter cheeks, more visible under-eye hollows, a less projected upper lip. The problem is that every one of those is also produced by lighting, lens distance, head posture, sleep and body fat. A phone camera held close exaggerates the centre of the face; one held at arm's length flattens it.

In medicine, an underdeveloped or set-back upper jaw is a real thing, and it is diagnosed by an orthodontist or an oral and maxillofacial surgeon using X-rays and an assessment of the bite and airway — not from a profile photo. If you have bite problems, jaw pain or trouble breathing through your nose, that is the route, and it is worth taking for reasons that have nothing to do with appearance.

Can it change?

In children and adolescents, orthodontists can guide upper-jaw development while the face is still growing — palatal expansion is the common example. In adults the options are largely surgical or surgically assisted, such as orthognathic surgery. Those are serious decisions with real risks and long recoveries, made with a specialist. Mewing is often sold as the non-surgical alternative; there is no good evidence it moves an adult maxilla, as does mewing actually work sets out.

What is changeable

Much of what gets blamed on the maxilla in a photo is the under-eye area, and that responds to things that are not bone: sleep, puffiness, darkness and the hydration of thin skin. Body composition changes the cheek and jaw line around it (the jawmaxxing guide). Those will not move a bone. They are the part of the midface you can work on this month.