Before surgery: what to prepare
Stop aspirin, ibuprofen, naproxen, and blood thinners 10–14 days before. Stop fish oil, vitamin E, ginseng, ginkgo. Smoking and vaping must stop 4 weeks before and through 6 weeks after, nicotine slows bone healing. Have any necessary dental work completed at least 2 weeks before. Stock liquid and soft foods for 2 weeks. Buy straws and a soft toothbrush. Arrange home help for the first 1–2 weeks.
The day of surgery
Square jaw reduction is performed under general anaesthesia, runs 2–3 hours, and usually requires one night in hospital. All incisions are inside the mouth so no external scar is visible. You wake up with a compression bandage around the lower face, drains in the cheeks, mouth packing, and the lower face already starting to swell significantly.
Days 1–3: peak swelling
Swelling peaks day 3–5 and is dramatic, the lower face looks much wider than the eventual result. Pain is moderate, well-controlled by medication. Drains usually come out before discharge. Strict liquid diet through a straw. Sleep with head elevated 45 degrees. Cold compresses on the cheeks outside the bandage for the first 48 hours. Do not lie completely flat, sleep at 30–45 degrees. Tongue edema in the first 24–48 hours can subtly compromise the airway; sit up and call the clinic if breathing or swallowing feels increasingly restricted. Mouth rinses with prescribed antiseptic after every intake of food or drink.
Week 1: stitches out, bruising fades
The compression bandage comes off around day 5–7. Swelling is still pronounced but visibly improving. Mouth opening is restricted (trismus). Bruising tracks down into the neck and front of the chest. Liquid diet continues. Numbness across the lower jaw and lower lip is significant, the inferior alveolar and mental nerves were stretched during surgery.
Weeks 2–4: back to public
Office work from the end of week 3 for most patients. Soft diet starts week 2 (porridge, scrambled egg, soft tofu), expanding toward normal-texture foods by week 4. No tough or crunchy food until cleared, usually week 6. Mouth opening continues to improve. Numbness is slowly improving.
Months 2–3: swelling resolves
Swelling drops dramatically between week 4 and month 3. The narrower jaw line becomes clearly visible. Mouth opening is near normal by month 3. Numbness in the lower lip and chin continues to improve but is not yet fully resolved.
Months 6–12: the final result
Bone consolidation runs 6–12 months. Result is essentially final by month 6 with minor refinement through month 12. Numbness in the lower lip is largely resolved for most patients by month 6; partial residual numbness past 12 months occurs in roughly 1–5% of patients and is occasionally permanent. A small subset of patients develop TMJ clicking, pain, or chronic dysfunction from altered joint loading; this should be flagged at follow-ups if it persists. The osteotomy line is structurally healed by month 12.
Red flags: when to call the clinic
Call the clinic the same day for: fever over 38.5°C after day 3, sudden firm painful one-sided swelling (haematoma), pus or foul taste from incisions, sudden inability to open the mouth, or numbness getting worse rather than better. Go to an emergency room for difficulty breathing or sudden severe airway swelling in the first 72 hours. Routine numbness, mouth-opening restriction, and asymmetric swelling in the first 4 weeks are not red flags.