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Lower Jaw Protrusion

Lower Jaw Surgery

Lower Jaw Protrusion


What is Lower Jaw Protrusion?

In ideal facial proportion the lower jaw is situated behind the upper jaw. But in facial discrepancy, the lower jaw may be located outside. This is a very common complaint in a maxillofacial patient. Not only the jaw, but also the teeth maybe in cross bite.

Disproportionate jaw can lead to problems with speaking, biting, chewing, swallowing, breathing, and undue stress on the temporomandibular joints system.   

Why does Lower Jaw Protrusion happen?

There are various genetic and developmental causes of lower jaw protrusion:

  • Genetic: There is a usually a familial trend in the disproportionate size of the lower jaw.
  • Hormonal disturbances: Over secretion of growth promoting hormones can lead to a class 3 bite.
  • Medical Conditions: Many syndromes are also associated with lower jaw protrusion. Therefore, it is imperative that a complete history is made.

What are the effects of Lower Jaw Prognathism?

From cosmetic to psycho-social there is an array of problems which can be associated with lower jaw discrepancy:

  • As this cosmetic deformity is attended during the growth phrase, it can lead to a reduced level of confidence.
  • The reverse bite may lead to extra stress of the dentition and may cause periodontal problems, difficulty in maintaining the oral hygiene, crooked teeth and loss of tooth.
  • As the bite is different, the stress on the joint is higher. This may lead to TMJ pain, and dysfunction in adult life.

Such discrepancies of the jaw can be corrected successfully using a wide array of treatment protocols which are set according to the patients age and preferences.  At Royal Cosmognathic, the attending doctor is a maxillofacial surgeon. Maxillofacial surgeons are the experts of such surgical treatment of jaw.

Know your treatment options?

Depending on the severity of the discrepancy and the age of the patient many treatment options are available. It is best to consult the concerned health care professional for an opinion.

  1. Orthopedic Appliance
    1. It is like a chin cup which is banded to the head. It provides a negative force and physically restricts the growth of the jaw. Major jaw discrepancies can be averted.
    2. This treatment modality can only be used for individuals in growing age that is when the permanent teeth are erupting, around 7-10 years of age.
    3. The biggest drawback is the need to wear a cumbersome appliance over the face. Such individuals may not accept this appliance when going to school or amongst their peers.
  2. Orthodontics
    1. In situations where the jaw discrepancy is minimal or patient is not bothered by the jaw discrepancy, but the teeth are not aligned, then use of braces is an option.
    2. It is best suited for individuals in the growing age before the age of 25 years.
    3. Orthodontic correction may require extraction of 1 or more teeth then physically pulling the teeth back into position. The treatment time of such cases can be long.
  3. Cosmetic Tooth Surgery
    1. In cases where the need of the patient is urgent or individuals are unsuited for orthodontic treatment, a cosmetic tooth correction of tooth can be done.
    2. Like braces, cosmetic tooth treatment can only camouflage the actual discrepancy. But the treatment can be completed in 1- 2 visits with minimal downtime.
  4. Orthognathic Surgery
    1. For moderate or severe discrepancies, where other conventional treatment options will not work a surgical intervention may be required.
    2. Traditionally the such treatments require a presurgical and post surgical phase of about 9 months each. Hence the treatment would be around 18 months in total.
    3. Advanced techniques with surgery first protocol, virtual surgical planning a surgical guide can be prepared. In such treatment protocols the treatment duration is reduced considerable. The treatment duration is reduced to a 3 day period with downtime of about 7 days.

What surgery can be performed?

Mostly commonly the lower jaw surgery involves the repositioning of lower jaw along with the dentition by placing cuts into the bone. Such a treatment is called as the sagittal split osteotomy. In cases where only the front of the lower required correction then a genioplasty or anterior segmental osteotomy can be performed.

The decision of the type of surgery required depends on the severity of the case and also the need of the patient. It is quite possible to avoid the sagittal split osteotomy by doing only a relatively minor chin repositioning. The final treatment procedure with complication should be discussed.

The advanced surgical protocols to expediate the treatment procedure with more stable outcome involve:

  1. Use of 3D models of before, during and after surgical.
  2. Use of virtual surgical planning to actually determine the bony and the dentition.
  3. Use of customized or prebend implants to reduce the surgical time.
  4. Enameloplasty or occlusal rehabilitation protocols to eliminate or limit the need for pre surgical orthodontics.
  5. Use of dental cosmetic and camouflage techniques to get the bite aligned.

Seldom does it happen that the facial discrepancy is only related to the lower jaw protrusion. There usually are 2 to 3 other minor facial features which will require treatment. Just to explain it better, a crooked nose would be masked by the jaw discrepancy. But once the jaw is corrected such a crooked nose would then stand out of place. Hence it is always advisable to seek a complete facial transformation surgery consult.

The most common procedures performed alongside the correction of lower jaw protrusion

  1. Upper jaw correction – Lefort 1
  2. Rhinoplasty – Aesthetic nose surgery
  3. Genioplasty – Aesthetic chin surgery
  4. Neck Lift – With the lower jaw pushed back, there can be excess fat dispositioning or skin redundancy in the neck. Hence, it is advisable to get a neck lift also done to correct this deformity. If the skin redundancy is also present on the face, then the neck lift may have to converted to a comprehensive face lift.
  5. Facial rejuvenation with prp or nano fat therapy  

What are the complications with such jaw surgeries?

All surgeries are performed under adequate anesthesia. Hence there is an inherent risk involved. Risk from the anesthesia itself is quite low because of the advancement in anesthesia and other safe practices. The surgery itself is not life threatening. Literature reports that the rate of complication is in such a surgery is as low as 4%. The complication may involves, a long term numbness of the lower lip, long term swelling of the face. Other complications can be related to the surgical complexities including hemorrhage, bad split of the jaw and hardware failure. Most of the complications can be managed either in the post- operative care or another surgical intervention at least 6 months later. Discuss the possibilities of complication and how can they be managed with your surgeon before proceeding for the treatment.

A typical post-surgical care includes:

1 – 2 days of hospital stay

5 – 7 days of bed rest with light movement

7 – 10 days for resuming work, school

2 months to get comfortable chewing

Weekly appointments are required upto two months

To get an expert opinion you can get a virtual consultation appointment here.

About Dr Chirag Chamria