In short. The examination establishes how the teeth meet, what the jaw angle is made of and where the width comes from, before either operation is named or planned.
Key points
- The bite and the outline are examined separately because they lead to different plans.
- A consultation that only looked at one of them has only answered half of what the patient came to ask.
The assessment for these two operations is really one assessment that answers two separate questions. It establishes how the teeth meet, and it establishes what the jaw outline is made of. The answers are reached in different ways, and it is worth knowing which one your consultation addressed.
Establishing the bite relationship
How the upper and lower teeth meet is examined directly, and where a discrepancy is found the question becomes whether it comes from the teeth, from the position of the jaws, or from both. That distinction decides whether orthodontic treatment alone can settle it or whether the jaws have to be repositioned. Where the jaws are involved, the plan is made jointly with an orthodontist, and it runs over more than one phase.
Establishing the outline
The width of the lower face is assessed from the outside and from imaging. The angle of the jaw is located in relation to the ear and the chin, the thickness of the bone is assessed, and the soft tissue over it is examined. This is the part of the assessment that decides whether contouring would change something, and how much.
Two assessments, one appointment
The bite and the outline are examined separately because they lead to different plans. A consultation that only looked at one of them has only answered half of what the patient came to ask.
Establishing what the width is made of
This is the step patients most often have not had. The lower face can read wide because the jawbone is wide, because the masseter muscle is thick, because there is fat beneath the skin, or because of a combination. Those have different answers, and only one of them is an operation on bone. Asking how much of the width is muscle is a reasonable question to put to the clinician examining you.
What the assessment should produce
A named finding, a plan that states which question it answers, and an account of what the other question would require if it turned out to be the real one. Where the bite is involved, the orthodontic phase belongs in the same conversation rather than a later one, because it changes the timeline and the number of appointments considerably. Where the width is muscle or fat, the answer is a different discussion.
Where the assessment should stop and refer
- A bite relationship that needs orthodontic treatment first, which is arranged before any operation is planned.
- Untreated dental or gum disease, which is treated before an operation on the jaws is considered.
- Width produced by muscle or fat rather than bone, which belongs to a different discussion rather than to either operation.
An assessment that separates the bite from the outline, and says which one it found, has done what these two operations require of it. What it should never produce is a plan for one of them before the other has been excluded.
Frequently asked questions
Does the assessment always need imaging?
Not always, and where an operation on bone is being considered it usually does. Imaging shows the position of the jaws, the shape of the angle and the position of the nerve canal, none of which can be established from the outside. What is done and when is decided by the clinical examination rather than requested in advance by the patient.
How can the assessment tell whether my wide jaw is bone or muscle?
By examining how the lower face behaves when the jaw is clenched and relaxed, and by feeling the consistency of the tissue over the angle. Muscle that thickens markedly on clenching contributes to the width in a way that bone does not. Where the finding is muscle rather than bone, an operation on the jawbone is not addressing what is producing it.
What should I leave the assessment with?
A named finding, an explanation of which operation that finding points to and why the other was not proposed, and an honest account of what the plan does not change. If the plan includes orthodontics, the orthodontic phase should be described at that appointment rather than later, because it changes the timeline.
Risks & Limitations
- Every operation carries risk, and no result can be guaranteed.
- Both operations work near the nerve that supplies the lower lip and chin, so altered sensation is possible. It usually improves, and it can be lasting.
- A corrected bite relationship can relapse, and a contoured jaw can be asymmetric or need revision.
- Final results are judged months later, once the swelling has resolved, not in the first weeks.
When to Seek Care
- Difficulty breathing, or swelling that is increasing rather than settling — seek emergency care immediately.
- Fever, or spreading redness, warmth or discharge around an incision.
- Bleeding that does not settle with gentle pressure.
- Pain that is worsening rather than easing, or a change in the bite that was not there before.
References & Further Reading
- American Society of Plastic Surgeons (ASPS) — craniofacial surgery guidance
- National Institute for Health and Care Excellence (NICE, UK) — relevant guidance
- Cochrane Library — systematic reviews
- Chinese Medical Association Plastic Surgery Branch — clinical guidance
This page is patient education, not medical advice, and it does not cite individual studies. Discuss your own case with a qualified clinician. To arrange an assessment at Chongqing West District Hospital, see Contact & Consultation.