Jaw Contouring Surgery: Patient Guide
The parent site in this cluster already answers what a chin operation is and whether to have one. This site answers the narrower question that follows: what changes when the target is the width of the lower face rather than its projection? Projection and width are two different operations on two different parts of the same bone, the width may come from bone, muscle or fat, and a nerve that moves the lower lip runs through the field the operation works in.
Reviewed by Tongchun Mao, MD, head of aesthetic surgery at Chongqing West District Hospital. Removing bone is easier than restoring it, the result is hidden by swelling for months, and no outcome is guaranteed.
Width is a different problem from projection
The word contouring covers two operations that share a bone and nothing else. A chin changes the profile; the jaw angle changes the face from the front, and confusing the two is how the wrong operation gets planned. What makes the jaw look wide may not be bone: the masseter muscle and the fat over it produce the same appearance and are treated differently, so the examination comes before any decision about what to reduce. A border is a change of plane, not a thickness of tissue, which is why the jawline is defined by where the mandible turns rather than by how much tissue sits over it. Removing bone is easier than restoring it, so over-reduction is the revision this operation most wants to avoid. Swelling hides the result for months: the face reads unevenly at two weeks and only approaches its final contour around six. And numbness of the chin and lower lip is expected and is watched rather than treated in the early weeks.
What jaw contouring changes, and what it leaves exactly as it was
Each card below is one thing that changes when the target is the width of the lower face. Read them as a boundary rather than as a list of benefits, because most of the disappointment in this area comes from expecting the operation to reach something it does not touch.
The jaw angle, seen from the front
The posterior part of the mandible is what makes the lower face read wide from the front. Reducing it narrows that width. What it does not do is change how far the chin projects, because the chin is a different part of the same bone and a different operation.
The mandibular border
The line from the angle forward to the chin is where a jawline is defined. A border is a change of plane rather than a thickness of tissue, so the assessment looks for where the mandible turns and whether that turn is visible, rather than for how much tissue sits over it.
Bone, muscle or fat
Three different layers can produce the same wide appearance. Bone reduction treats the bone, the masseter muscle is a separate target treated by a different means, and fat over either is treated differently again. The examination is what separates them, and it comes before any decision about what to reduce.
The nerve that shapes the plan
The marginal mandibular nerve runs through the field the operation works in, and it moves the lower lip. The plan is built around its course rather than the nerve being discovered during the operation. A weakness after surgery is usually temporary, and it is the risk this operation is organised around.
Asymmetry you had not noticed
Imaging shows differences between the two sides of the jaw that an examination cannot, and a plan that reduces both sides by the same amount can make a pre-existing asymmetry more visible rather than less. What the scan adds is a measurement of each side rather than an impression of them.
What the soft tissue does afterwards
The skin, the fat and the muscle over the new contour do not automatically redrape to it. In a younger face they usually follow the bone closely; where the soft tissue is heavier or has lost elasticity, the change in the bone may read less clearly than the plan suggests.
The result the swelling hides
Swelling after this operation is substantial and it is uneven on the two sides. At two weeks the face is still swollen enough to hide the contour; at three months most of it has gone; at six the contour is close to final. The early appearance is not the result, and it is not a reason to plan a revision.
Everything the operation does not reach
It does not lengthen a short face, correct a bite, change the position of the teeth, or alter the soft tissue. Where the complaint is one of those, the answer lies elsewhere, and a plan that implies otherwise is a plan that will not deliver what the patient asked for.
Who is a candidate, and who is not
The physical requirements are specific. The bone has to be thick enough to remove safely along the planned line, which is established from imaging rather than from the examination alone. The nerve's course has to be identified so the plan can be built around it. The teeth and the bite have to be stable, which usually means orthodontic treatment is finished or not planned. And the healing has to be reasonable, which means no smoking, controlled blood pressure and no condition that impairs the blood supply to the bone. Beyond the physical requirements there are considerations of age and of motive. Age matters because the bone has to be mature and because the soft tissue has to be able to follow the new contour. Motive matters more. A patient who is narrowing the jaw because somebody told her it was wide, or because she wants a particular face from a photograph, is asking an operation to do something it cannot, and the assessment is where that should be said. Where the width comes from muscle or from fat, the correct answer is often not this operation at all.
What is actually producing the width
This is the decision that matters most in this area of surgery, and it is a diagnostic one. The operation follows from which layer is responsible, and the commonest error is to plan a bone operation for a muscle or a fat problem.
Reducing the jaw angle
Where the posterior mandible is the cause, reducing it narrows the lower face from the front. How much can be removed is limited by the thickness of the bone and by the course of the nerve, both of which are established before the operation. The change is to the border and the width, and not to the profile.
The masseter muscle as a target
A heavy masseter produces a wide lower face that is soft rather than angular and that becomes more prominent when the teeth are clenched. It is treated by a means that does not involve removing bone, and its effect is temporary rather than permanent, which is a real difference and not a defect.
Fat as a third target
Fat over the jaw or under the chin produces an appearance that patients often describe as a wide jaw. Removing fat does not change the bone and does not narrow the skeletal width; it changes what sits over it. Where fat is the finding, a bone operation is the wrong answer.
Combining bone with a chin change
Where projection and width are both complaints, two parts of the mandible are addressed rather than one. This is a longer operation and it is planned as such. The two are separate measurements, and a plan that treats them as one decision usually satisfies neither.
Leaving the bone alone
Where the examination and the imaging show that the width comes from muscle or from fat, the honest plan does not involve the bone at all. This is the commonest correct outcome of an assessment for jaw contouring, and it is worth saying plainly rather than treating it as a disappointment.
Where the plan has to stop
The amount of bone that can be removed is limited by what remains structurally and by the position of the nerve. That limit is decided before the operation from imaging rather than adjusted during it, because the consequences of exceeding it are permanent and are not correctable by a second operation.
Months of swelling, and a result that hides behind it
Swelling is at its worst from the start and the face feels tight and heavy, with a compression band worn and talking effortful. Swelling and bruising peak around the third day, and the first week is a soft diet with no chewing on hard food; the jaw aches rather than hurts at rest. By the second week the bruising has faded and most people can be in public, and the swelling still hides the result and is uneven on the two sides. From three to six weeks the lower face softens week by week, and numbness of the chin and lower lip is expected and is watched rather than treated at this stage. Between two and three months there is a first honest look at the width and the border, with residual swelling and returning sensation both changing the picture. At six months most of the swelling has gone and the contour is close to final, and numbness still present at that point is less likely to resolve fully. Final judgement belongs at around a year, which is also the earliest point at which a genuine asymmetry or an over-reduction can be assessed and a revision considered.
The nerve, the bone, and the asymmetry the operation can reveal
The general risks of any operation under anaesthesia apply, including bleeding and infection. The risks specific to this operation are three. The first is the marginal mandibular nerve: a weakness of the lower lip after surgery is usually temporary and usually resolves over weeks to months, and a lasting weakness is uncommon but possible, which is why the plan is built around the nerve's course rather than around the amount of bone that could be removed. The second is the bone itself: removing too much is the error this operation most wants to avoid, because bone that has been taken away cannot be restored to what it was, and a contour that has been over-reduced is difficult and sometimes impossible to correct. The third is the asymmetry that becomes visible once the swelling settles: the two sides of a jaw are rarely identical to begin with, and a plan that reduces both by the same amount can make a pre-existing difference more apparent. Numbness of the chin and the lower lip is expected rather than a complication, and it is watched over months. Swelling that persists beyond the expected period is assessed rather than waited out.
What else could answer the same complaint
If the width comes from the masseter muscle, a treatment that relaxes the muscle addresses it without an operation, and its effect is temporary, which means it is both a treatment and a trial of the diagnosis. If the width comes from fat, removing fat is the answer and does not narrow the bone. If the complaint is projection rather than width, that is a different part of the mandible and a different operation. If the complaint is that the jawline lacks definition because the soft tissue is heavy rather than because the bone is wide, the answer may be in the soft tissue. If the complaint is that the face is short or that the bite is wrong, neither is addressed by contouring and both belong with a different assessment. And where a patient wants to rehearse the appearance of a fuller or narrower contour, adding filler shows a fuller shape and does not preview the result of removing bone, which makes it a poor test of this particular operation.
The surgeon responsible for these guides
This site is medically reviewed by Tongchun Mao, MD, Deputy Director of the Plastic Surgery & Aesthetics Medical Center and head of its aesthetic surgery service at Chongqing West District Hospital. He operates inside a tertiary general hospital, with imaging, anaesthesia, laboratory workup and intensive care in the same building as the operating theatre, which is what this operation needs: the imaging that establishes bone thickness and the nerve's course before the plan is made, and the hospital-level care for the complications that are uncommon but consequential. He is supported by Dr. Shaoliang Wang on complex and previously operated cases, by Dr. Ke He on the assessment of what a non-surgical route could change, and by Dr. Yongbo Jia on the skin and soft tissue that have to follow the new contour. Read the full team profiles.
Where this decision sits in the cluster
If you have not settled whether to have a chin operation at all, start with the overview of chin surgery as a decision, which answers that question and is not repeated here. If the complaint is that the jawline lacks definition rather than that the face is wide, the account of a weak jawline and what defines it is the place to start. If the two sides of your face differ, the guide to facial asymmetry covers a finding this operation can reveal as well as correct. If you are weighing bone surgery against an implant, the comparison of an implant and an injectable explains why the two are not substitutes. If the question is whether the jaw itself or the soft tissue over it needs treating, the side-by-side comparison of bony and soft-tissue approaches sets out what each changes, and the hub on facial aesthetics places all of it inside the wider subject.
The jaw contouring recovery timeline
What happens, and roughly when, from the day of operation to the point at which the result of jaw contouring can honestly be judged. The dominant feature is swelling, which hides the contour for months and resolves unevenly on the two sides. Your own team's instructions take precedence over any general timeline.
The decision, in twelve parts
Each guide takes one question that only arises when the target is the width of the lower face: which layer is responsible, where the nerve runs, what imaging adds, and what cannot be added back once bone is removed. Read the two or three that match where you are.
Chin Projection and Jaw Width Are Two Different Operations
A chin changes the profile; the jaw border changes the face from the front. Confusing the two is how the wrong operation gets planned and paid for.
Read the guide →The Jaw Angle: What Changing It Does From the Front
The posterior mandible is what makes a lower face read wide. What reducing it changes, and what it leaves exactly as it was.
Read the guide →Bone, Muscle or Fat: Which Layer Is Making the Jaw Look Wide
Three different targets with three different treatments. Why the examination comes before any decision about what to reduce, and what each finding feels like.
Read the guide →The Mandibular Border: Where a Jawline Is Defined, and Where It Is Lost
A border is a change of plane, not a thickness of tissue. What the assessment looks for along the line from the angle to the chin.
Read the guide →Who Is a Candidate for Jaw Contouring, and Who Is Not
The physical requirements, the age and healing considerations, and the motives that make an operation a poor idea even when it is technically possible.
Read the guide →The Marginal Mandibular Nerve: The Risk That Shapes the Plan
The nerve that moves the lower lip runs through the operative field. How its path is respected, and what a temporary or lasting weakness means.
Read the guide →Start by finding out which layer is wide
Arrange an assessment. We will establish whether the width comes from the bone, the muscle or the fat, what imaging shows about how much can safely be removed, and where the nerve runs in your case.
Frequently asked questions
Does jaw contouring change the profile or the front view?
The front view, mainly. The posterior part of the mandible is what makes the lower face read wide from the front, and reducing it narrows that width. Projection is a different part of the same bone and a different operation. A plan that treats width and expects the profile to change has confused two operations, which is why they are measured separately.
How do I know whether the width is bone, muscle or fat?
From the examination rather than from a mirror. A heavy masseter becomes more prominent when the teeth are clenched and feels soft rather than angular. Fat over the jaw changes when the face is lifted. Bone is what remains when both have been allowed for, and imaging establishes the rest. The three are treated differently, so the examination comes before any decision.
Can the jaw be made wider afterwards if too much is removed?
It is difficult and it is the reason this operation is planned conservatively. Bone that has been removed cannot be put back as it was, and material added to rebuild a contour does not behave like the bone that was taken away. Over-reduction is therefore the error the operation most wants to avoid, and the limit on how much can be removed is decided before the operation rather than during it.
Will my lower lip be affected?
The nerve that moves the lower lip runs through the field the operation works in, so the plan is built around its course. A weakness after surgery is usually temporary and usually resolves over weeks to months, and a lasting weakness is uncommon but possible. It is the risk that shapes the plan rather than a complication discovered afterwards.
How long before the swelling goes down?
At two weeks most people are presentable and the swelling still hides the result. At three months most of it has gone and the contour can begin to be read. At six months it is close to final. The two sides resolve at different rates, so the face looks uneven before it looks even, and judging it earlier is the commonest source of unnecessary worry.
What if the width comes from the muscle rather than the bone?
Then the honest plan does not involve the bone at all. A heavy masseter is treated by a means that relaxes it, and the effect is temporary rather than permanent, which makes it both a treatment and a test of the diagnosis. This is a common outcome of an assessment for jaw contouring rather than a rejection.
Part of Chin and Jawline — 14 sites on this topic