Facial disproportions occur due to a combination of alterations of the facial bones, leading to facial imbalance and if severe enough facial deformity. Patients commonly present with large or small jaws, asymmetries or a combination causing difficulties biting or eating certain foods leading to poor quality of life and impact on self-confidence.

Variable degree of dento-facial disproportion can commonly occur due to: congenital/ hereditary disorder, facial growth discrepancies or secondary to trauma of the jaw growth centres during childhood.

What is Orthognathic/ Jaw surgery?

Orthognathic or jaw surgery is designed to treat the bones of the face (jaw, maxilla, zygomatic or malar bones, nasal bones, orbit and teeth), in order to correct underlying conditions of the jaw related to structure, growth discrepancies, airway issues including obstructive sleep apnoea, TMJ disorders and severe dental misalignment/ malocclusion problems that cannot be treated with braces, to improve function and aesthetics.

The benefits include: facial harmony/ balance, correct asymmetries/ misalignment, improved chewing, speech, breathing, dental appearance, quality of life, self-esteem and self-confidence.

Surgery duration: Single jaw 1-2hour
Upper and lower jaw 3-4hours
Upper & lower jaw and chin surgery 4-5hours

Type of anaesthesia: General anaesthesia
Hospital stay: 1-2nights
Recovery time: 3-6weeks

What are the common problems that may require jaw surgery?

When an individual’s midface or jaws fail to grow or develop normally, facial disproportion occurs depending on the direction of growth deficit or excess resulting in big size mismatch between upper & lower jaws, a large asymmetry, or a gap between upper & lower front teeth, which will have an influence on chewing function and facial appearance.

Small lower jaw (retrognathia)

The lower jaw fails to grow forwards adequately. This can result in inability for your lower front teeth to meet behind your upper front teeth, leading to eating difficulty and concerns with small, lower jaw side profile appearance.

Large lower jaw (prognathia)

The lower jaw protrudes further than top jaw. This can result in eating difficulty as the lower teeth sit infront of the upper teeth, called reverse overjet. The side profile of a disproportionately lower larger jaw is often a cosmetic concern for some.

Facial asymmetry

The lower and/ or upper jaw growth is deficient or excessive on one side result in facial asymmetry. It is essential to identify and address the underlying cause first, before any corrective surgery, to avoid poor surgical outcomes. Facial asymmetry can present with eating difficulty, dental misalignment/ malocclusions (not correctable with braces), painful jaw joints and muscles of mastication (chewing muscles) and facial appearance concerns.

Small upper jaw (hypoplastic maxilla)

The upper jaw can fail to grow forwards or 3-dimensionally to adequate proportions to achieve facial harmony. This can result in dental malocclusion with upper teeth sitting behind the lower teeth, leading to difficulty eating, chewing and pain associated with muscles of mastication (chewing muscle). The common appearance concerns are the perception of lower jaw being too prominent and upper teeth not showing when smiling (giving an aged look), which can result in self-confidence issues.

Large upper jaw

The upper jaw grows forward or 3-dimensionally further than desirable. This can present with a ‘gummy smile’ and potentially problems with self-confidence. It is important to establish between hyperactive muscles of lip or excessive growth of upper jaw is the underlying cause of a ‘gummy smile’ as the treatment of hyperactive muscle is Botox injection and the latter is jaw surgery.

Open Bites

When the disproportionate jaw growth is in the vertical direction, the result is that the teeth are unable to meet at the front (termed anterior open bite) or at the side (termed lateral open bite), causing difficulty biting or chewing foods. It is essential to exclude underlying dental causes, to achieve good surgical outcomes.

What are the stages involved for jaw surgery?

Corrective jaw surgery (orthognathic surgery) may be offered as a treatment option as it moves the jaw or jaws (upper & lower) into a new position that is more balanced, functional and healthy with the teeth meeting normally. Jaw surgery is an elective procedure and you should allow yourself plenty of time to weigh up the benefits and risks of this complex treatment.

On average, the entire treatment will take 2-3 years to complete. Surgery occurs two thirds of the way through your fixed brace treatment.

Stage 1: Assessment of suitability for jaw surgery and INITIAL planning.

Stage 2: Alignment of teeth, with fixed braces, in preparation for jaw surgery. (Duration: ~18 months and longer in more complex cases).

Stage 3: Jaw surgery planning when fixed brace treatment is confirmed to be complete by your orthodontist. This is done by face to face clinical assessment/ measurements, along with 3D-Virtual surgical planning computer software technology. X2 Consultations 2-4weeks PRIOR to surgery date.

Stage 4: The jaw surgery is performed under general anaesthetic and you should expect to have one or two nights in hospital afterwards. Once discharged, recovery takes between three and six weeks.

Stage 5: After the operation you will need at least 4 to 6 months of fixed brace treatment to fine tune the fit of your teeth. You are required to wear retainers for life to prevent your teeth from moving back.

This combined treatment is available on the NHS, provided your jaw growth discrepancy fulfils IOTN/ IOFTN severity criteria ³ 4. Book your consultation or ask your dentist or orthodontist to refer you:

  1. If you are considering having orthodontic treatment and jaw surgery (combined treatment) but you’re not sure if you’re a suitable candidate for this and would like to know all your options or you’re stuck on a NHS waiting list to be seen in an initial consultation clinic. Self-refer or ask your dentist to refer.
  2. If you have undergone the pre-surgical orthodontic treatment (brace treatment to align your teeth for surgery) and you’re stuck on a NHS waiting list for surgery in your local hospital or wish to have a choice in when the surgery is done, who or where it is done. Ask the Orthodontist providing your brace treatment to refer when you’re ready for surgical planning.

The success of the combined treatment, to achieve optimal occlusion (bite or coordination between your upper & lower teeth) and facial aesthetic requires good communication and team work between the surgeon, orthodontist and prosthetic laboratory technicians.

Surgical Planning Process:

Ms. Lwin will liaise directly with your orthodontist as soon as referral letter is received from them and review various clinical information needed. Depending on what your orthodontist can provide, the pre-surgery consultation may be reduced to x2-3 visits for surgical planning and surgical wafer/splint/guides try-in, prior to your surgery.

We provide BOTH traditional (2D) and 3D-Virtual Surgical Planning (VSP) with 3D-printed surgical splints/guides manufactured on-site. The usual time from first consultation with Ms. Lwin, when an assessment is made and a surgical plan is formulated for optimal improvement in function (ie. Occlusion/ bite) and aesthetic (ie. Harmony in facial proportions) to complete traditional or 3D-VSP for surgical splints to be made by laboratory technicians is 3-4weeks.

If you’ve medical insurance, you’ll need to check that you are covered for the laboratory work needed for traditional or 3D-VSP, otherwise there will be a charge from the laboratory. It is Ms. Lwin’s preference to do all the surgical work-up necessary (up to date upper & lower arch impressions, wax bite registrations, facebow record for traditional and CT-scan for 3D-VSP, on site) to ensure accuracy. However, for self-paying individuals, costs may be reduced, by your local orthodontist doing some of the pre-surgical work-up on the NHS and Miss. Lwin will liaise with them and send them the protocol for CBCT-scan, head positioning, and wax registration to ensure accuracy in 3D-VSP.