In short. How orthognathic surgery is planned: the joint orthodontic and surgical plan, CT scanning and 3D modelling, surgical guides, and the sequence of appointments a jaw operation depends on.
Key points
- Three-dimensional modelling lets the surgeon rehearse the movement on screen and see the effect on the chin, the airway and the symmetry before anything is cut.
- A surgical guide is a small custom-made template, printed from that plan, that transfers the planned position to the operating table.
- Guides reduce error; they do not remove it, and they do not replace surgical judgement.
Orthognathic surgery is the operation that moves the upper jaw, the lower jaw, or both into a position where the bite works and the face is balanced. It is not decided in a single appointment. A predictable jaw operation is the product of a plan built jointly by the orthodontist and the surgeon, a plan that begins months before the theatre date and continues long after it.
Why two specialists, not one
Teeth sit on bone. Moving the bone without moving the teeth produces a straight jaw with a crooked bite; moving the teeth without moving the bone leaves the jaws in the wrong relationship and the orthodontics unstable. The orthodontist therefore prepares the dental arches first, so that when the jaws are repositioned the teeth already fit the intended relationship. This preparatory phase commonly runs twelve to eighteen months, and its length is one of the first things a patient should ask about.
The records that make the plan
Planning rests on measurement. Clinical photographs, dental impressions or intraoral scans, a lateral cephalometric radiograph, and a CT scan are combined. The CT allows the skeleton to be viewed and measured in three dimensions, so that the actual distance each jaw must move, and the direction of that movement, are calculated rather than estimated. Where the airway or the jaw joints are involved, those are assessed in the same workup.
What 3D planning and surgical guides do
Three-dimensional modelling lets the surgeon rehearse the movement on screen and see the effect on the chin, the airway and the symmetry before anything is cut. A surgical guide is a small custom-made template, printed from that plan, that transfers the planned position to the operating table. Guides reduce error; they do not remove it, and they do not replace surgical judgement.
The sequence
Pre-surgical orthodontics straightens and aligns the arches. The operation repositions the bone, and the jaws are held in their new relationship with small plates and screws while they heal. Post-surgical orthodontics then finishes the bite over the following months. Some cases are planned in the opposite order, with surgery first, when the discrepancy is severe enough that the teeth cannot be aligned beforehand.
What the plan should tell you
Before consenting, you should be able to state the planned movement, the number of nights in hospital, the expected period on a soft diet, the time away from work or study, the numbness that may occur around the lip and chin, and when the final result will be assessed — normally six to twelve months after surgery. If any of those is vague, the plan is not finished.
Ask these questions before surgery
- How many millimetres will each jaw move, and in which direction?
- What is the plan if healing or the bite does not follow the prediction?
- What will I be able to eat, and when can I return to work, study or sport?
Frequently asked questions
Why does jaw surgery need an orthodontist as well as a surgeon?
Because teeth sit on bone. Moving the bone without moving the teeth produces a straight jaw with a crooked bite, while moving the teeth without moving the bone leaves the jaws in the wrong relationship and the orthodontics unstable. The arches are prepared first, commonly over twelve to eighteen months.
What records are needed to plan orthognathic surgery?
Clinical photographs, dental impressions or intraoral scans, a lateral cephalometric radiograph, and a CT scan, which lets the skeleton be measured in three dimensions so the distance and direction each jaw must move are calculated rather than estimated. The airway and the jaw joints are assessed in the same workup.
What should a finished jaw surgery plan tell me?
The planned movement, the number of nights in hospital, the expected period on a soft diet, time away from work or study, the numbness that may occur around the lip and chin, and when the final result will be assessed — normally six to twelve months after surgery. If any of those is vague, the plan is not finished.
Risks & Limitations
- Reconstruction is usually staged — more than one operation is normal, and the plan may change as healing progresses.
- Donor-site scarring and discomfort, including after rib cartilage harvest.
- Partial or complete failure of a flap or graft, which may require further surgery.
- Scars are permanent. They mature and fade but never disappear.
- Asymmetry and the inherent limits of matching a normal side.
- Altered sensation, numbness or weakness in the operated area.
- Contracture, which may need release procedures later.
- Final assessment is made at 6–12 months, and longer in growing children.
When to Seek Care
- A flap or graft that turns dark, cold, black or stops bleeding when pricked.
- Fever above 38 °C, or spreading redness, warmth or discharge around a wound.
- New or worsening pain, swelling or fluid leakage from the operative site.
- Bleeding that does not stop with gentle pressure.
- Any change in a reconstructed area that concerns you, however minor.
References & Further Reading
- American Society of Plastic Surgeons (ASPS) — reconstructive surgery guidance
- World Health Organization (WHO) — burn and trauma care resources
- Chinese Medical Association, Plastic Surgery Branch — clinical guidance
- Cochrane Library — systematic reviews in wound and reconstructive care
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.