In short. Both operations work near the same nerve and both carry bleeding and swelling risk. What differs is the route taken and the consequences of each complication.
Key points
- A patient considering either operation should hear that nerve injury is possible, that it usually improves, that it can be lasting, and what happens if it does not return.
- Being told this about one operation and not the other is a sign the comparison is being made for you.
Both operations work in the same region of the face, and they share a set of risks that should be described in the same terms on both sides. What differs is the route each operation takes and what each complication means once it has happened.
The nerve both operations work near
The nerve that carries sensation from the lower lip and the chin runs through the jawbone and emerges near the chin before branching into the soft tissue. An operation that repositions the jaws works on the bone the nerve passes through. An operation that reshapes the angle works on the same bone further back. Neither can be described as avoiding the nerve, and a patient should hear that stated the same way for both.
Bleeding, and why the region matters
Both operations carry a risk of bleeding, and in jaw surgery it matters more than in many operations because of where the bleeding occurs. Swelling follows the operation and is expected. Swelling that increases rather than settles, or any difficulty with breathing, is a reason to seek care immediately.
The same risk, stated the same way
A patient considering either operation should hear that nerve injury is possible, that it usually improves, that it can be lasting, and what happens if it does not return. Being told this about one operation and not the other is a sign the comparison is being made for you.
Relapse and asymmetry
Relapse belongs to the operation that changes a bite relationship: the jaws move away from where they were planned. It is why the plan involves an orthodontist and why the result is reviewed over time. Asymmetry belongs to both, because the position of the bone on the two sides has to be balanced and the two sides of a face are not identical to begin with.
Infection, healing and the airway
Infection is a risk of both, and it is treated rather than watched. Problems with the way bone heals belong mainly to the operation that cuts and repositions the jaws. Difficulty with the airway in the period around the operation is a specific concern of jaw surgery, which is one reason it is performed as an inpatient procedure with monitoring rather than as day surgery.
What to establish before consenting to either
- That nerve injury has been described to you in the same terms for both operations, not as one side’s problem.
- What the plan is if sensation does not return, and who follows it up rather than leaving it to you to raise.
- Which risks belong to the operation proposed, which would apply to the other, and what would be done if one occurred.
Neither list of risks is short, and they are different rather than unequal. A patient who has been told which risks belong to which operation is in a position to decide between them.
Frequently asked questions
Is numbness after jaw surgery permanent?
In most people it improves over weeks to months, and in a proportion it does not fully return. That is why it belongs in the consent conversation for both operations rather than being mentioned as an afterthought. Reduced rather than absent sensation is more common than complete numbness, and it is followed up rather than left to the patient to raise.
What is relapse, and how likely is it?
Relapse means the bite relationship moving away from where it was planned, and it is a recognised possibility in any operation that changes the jaws. The plan reduces the risk by settling an unstable bite first and by involving an orthodontist throughout, and it does not remove the risk. A change in the bite afterwards is assessed rather than assumed to be expected.
Is bleeding a serious risk in these operations?
Bleeding is a risk of both, and in jaw surgery it matters more because of where the bleeding occurs. It is managed with the usual surgical measures, and the swelling that follows is part of the recovery rather than a sign that something has gone wrong. Swelling that increases rather than settles, or difficulty breathing, is a reason to seek care immediately.
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.