What is Underbite Jaw Surgery?

Underbite Surgery
Orthognathic surgeries have gained popularity over the years with development in cosmetic procedures. Underbite surgery is a corrective orthognathic surgery for correcting the protruding lower jaw. The lower jaw malposition makes the chin or mandible appear jutted out which is visually displeasing. Corrective measures for this condition include invasive and non invasive procedures for adults and children.

What is an under bite?


Not everyone around has the Willy Wonka smile. Some people have disproportionately placed teeth because their upper jaw and their lower jaw don’t fit together. The disharmonies in their teeth make them look unappealing because of the way their teeth fit together. Underbite is described as a Class III malocclusion (bad bite), which occurs due to the abnormal extension or protrusion of the lower jaw (Mandible) in front of the upper jaw (Maxilla). Due to the underbite, the chin and the lower jaw teeth get prominence. In most of the under bite cases, the malocclusion can be corrected with non-invasive correctional techniques like braces. But in the extreme cases, underbite can distort the facial structure and appearance of a person, causing social anxiety over looks. Severe underbite cases called as the skeletal malocclusions dramatically alter a person’s speech abilities. It is said that around 5 – 10% of the world’s population has some type of underbite malocclusion. The cause of this underbite is said to be mostly genetic, but there are some underlying secondary causes like tongue thrusting, long-term use of the pacifier or bottle, poor chewing habits, tumors in jaw bones, mouth-breathing or thumb sucking which might worsen the condition.

What is the process?

Doctors resort to corrective jaw surgery or the orthognathic surgery if the condition cannot be corrected by braces. The orthognathic surgery is a complex procedure which has two possible treatments, first is cutting the bone to realign the upper jawbone forward and the second is cutting the lower jaw bone and repositioning it to realign the chin and teeth back. It is a complex procedure which requires major scrutiny of the causes and severity of the condition. In some extreme cases, both the surgery procedures might be performed for gaining maximum results. The orthognathic surgery is generally recommended for patients with severe to moderate underbite malocclusion. The surgery is a costly affair as it involves expertise of various medical professionals and hence it should be an informed decision. Not all medical insurances cover this surgery and hence it can be heavy on the patient’s pocket. A patient should also consider various risk factors involved in the procedure before opting for it like numbness of the lip if any facial nerve gets damaged in the surgery, infection and other complications.

Non-invasive methods for Underbite correction

The traditional treatment option for patients with the severe underbite malocclusion involves a combination of surgery as well as orthodontic treatment (braces). Those who don’t want to go for these invasive procedures of treatment can opt for the in-office treatment procedures which are comparatively non-invasive. Not every patient can undergo non-invasive treatment. Severity of the condition is the single biggest deciding factor when it comes to opting for a treatment procedure. If the underbite is caused by skeletal (abnormality of the jaw) rather than dental (improper placement of the teeth) deformity, surgery is the only option. Those with mild cases of underbite could opt for in-office corrective treatment procedures like restorative dentistry, dental veneers and removable oral appliances. Patients with fewer complications can opt for this alternative treatment as compared to the expensive traditional treatment through surgery, orthodontic treatment, extraction and, on some occasions, a combination of all these procedures. The risks, complications and recovery time for alterative procedures are far too less as compared to the invasive treatment options. The only downside to this procedure is that only a few patients who have absolutely mild underbite malocclusion can qualify for this treatment.

Treatment Options

Surgery for underbite correction is said to have better results when the patient is still in his / her growth years. For younger patients who are still in their growth years, surgery as a treatment option is avoided if possible due to its long-term effects. Patients with the underbite experience various problems related to the condition if left untreated – like eating disorders, low self esteem in adults because of deformed facial structure, bullying experienced by kids or poor oral health. Underbite also leads to Temporomandibular joint disorder (TMJ), a joint disorder that causes pain, tenderness and clicking and popping of the jaw.

Underbite correction in kids

For children diagnosed with underbite, surgery should be considered as the last option. Your dentist might recommend upper jaw expanders or palatal expanders, a plastic wire mould designed to fit the upper jaw for widening it. Pressure is created on the upper jaw-line by turning a midline screw at selected intervals so that the upper teeth align themselves with the lower ones over time. As a part of the treatment process the patient is given a small wire key to be used to expand the mould. Reverse-pull face mask may also be used as a treatment option for kids and needs to be worn 12 to 14 hours a day. Chin cap is another treatment option used by dentists to restrain or redirect the growth of the lower jaw (mandible).

Underbite correction in adults

The treatment for underbite in adults varies between surgery, orthodontic treatment and extraction. A patient might be asked to undergo a certain period of correction through braces, before and after the surgery for better alignment and positioning of the teeth as the surgery causes repositioning of teeth. The surgery is generally performed under local anaesthesia and takes about one to seven hours to complete, depending upon the complication. A maxillofacial surgeon separates the bone in the rear portion of the jaw from the front and then reshapes the jawbone. Then the lower jaw, teeth and chin are modified and repositioned to complete the alignment process. For holding the jaw alignment in position, surgical plates, rubber bands and wires are used. All of the surgical incisions are made inside the mouth for cosmetic purposes. Post surgical healing process involves a strict diet and abstinence from tobacco. Patients can resume work within three weeks of surgery, with partial healing in 6 weeks and complete healing 9 to 12 months in all.

Costs involved

Various medical professionals work on the surgery and hence the cost of surgery is expected to be high. The cost of an underbite correction surgery involves cost of the anaesthesiologist, the orthodontics, the maxillofacial surgeon and the post surgery care costs. Other contributing factors are the severity of the condition, complications and treatment plan recommended by the dentist. A general estimation of the cost involved stands between $20,000 to $30,000, all inclusive.