The essential role of masseter muscle is for adequate mastication. This bulky muscle is located laterally to the mandibular ramus, and thus plays an important role in facial aesthetics. Masseter hypertrophy is recognized as an asymptomatic enlargement of one or both masseter muscles. A hypertrophied masseter will alter facial lines, generating discomfort, and create negative cosmetic impacts in many patients. This leads to the prominent mandibular angle which is considered to be aesthetically unacceptable. The muscle function may also be impaired, thus resulting in conditions such as trismus, protrusion, and bruxism.
In most cases of masseter hypertrophy, it is bilateral and symmetric, but asymmetry is not unusual. In majority of the cases, the etiological factor is unknown therefore it is considered to be idiopathic. Unilateral occurrence can also be seen when patients chew or clench primarily on one side.
There are various treatment modalities for the management of masseteric hypertrophy. The aim of the treatment is to improve facial balance, change the shape of an overly square face and relief pain or discomfort as a result of an overly large masseter muscle.
TREATMENT MODALITIES
1. Non Surgical Treatment
Conservative management of the idiopathic masseter hypertrophy includes psychological counselling, use of mouth guards, muscle relaxant, anxiolytic drugs, analgesics, physical therapy, dental restorations, and occlusal adjustments to correct premature contacts. A good result can be achieved in the patients with mild hypertrophy but there is no reliable success rate of isolated clinical therapy. Injection of botulinum toxin type A (Botox) into the masseter muscle was considered as less invasive modality for the treatment of muscle hypertrophy. Local injection of very small doses of the Botox into a muscle produces local paralysis and therefore, individual muscles can be selectively weakened and atrophy of the muscle occurs. Perhaps the biggest disadvantage of botulinum toxin therapy is that the treatment effect wears away and reverts to the original condition in 4 – 6 months. Unlike surgical excision of muscle tissue that reduces the actual number of muscle cells, botulinum toxin type A only reduces muscle volume temporarily.
2. Surgical Treatment
This surgical treatment consists of removal of 3/4 to 2/3 of all muscle mass via intraoral approach. Occasionally, mandibular cortical bone or angle osteotomy can also be performed at the same time to achieve a streamlined jawline contour. The surgery to access the masseter muscles and the mandible (jawbone) is performed through incisions on the inside of the mouth, between the gum and cheek (lower buccal sulcus area), leaving no visible scarring. Once the correct amount of bone and muscle has been removed, the incision is closed with self-dissolving sutures. The result of surgical approach to masseteric hypertrophy is predictable and longer lasting compared to non surgical method.
CANDIDATES
- Having a positive outlook and specific goals in mind for improvement of facial appearance.
- Physically healthy with no active or serious pre-existing medical conditions
PRE-OPERATIVE EVALUATION
Communication is vital in order to achieve the patient’s goals. During the initial consultation, patients will have the opportunity to discuss their goals and desirable results with the plastic surgeon. The plastic surgeon will work closely with the patients to reach an agreement about the expectations from the surgical procedures involved and their long term benefits. Every patient is different, therefore a specific treatment regimen is planned to suit an individual’s need.
- Discussion about patients’ expectations and desired outcome
- Medical conditions, drug allergies and previous medical or surgical treatment
- Use of current medications, vitamins, herbal supplements, alcohol, tobacco and drugs
- Previous surgeries
- Examination of the face and its soft tissues
- Radiological assessment (CT scan of face) if necessary
- Preoperative evaluation for general anaesthesia
- Photography for preoperative and postoperative evaluation
PREPARATION
- Blood investigations or a medical evaluation
- Avoid certain medications or adjust your current medications
- Stop smoking or alcohol well in advance of surgery, (2-3 weeks prior to the surgery)
- Avoid taking aspirin and certain anti-inflammatory drugs and herbal supplements as they can increase bleeding
RISK
It is essential for patients to understand that every surgical procedure has its own complications and risks involved. However, if a patient is assessed properly before the surgery and postoperative care is given adequately, these risks can be eliminated or reduced. The risks involved in masseter muscle reduction surgery are:
- Bleeding
- Blood clot
- Infection
- Bruises and swelling
- Injury to the surrounding nerves, blood vessels, muscles or bones
- Changes in the skin sensation at the lower lip (temporary)
- Asymmetry
- Anaesthesia risks
- Possibility of revision surgery
POST-OPERATIVE EXPECTATIONS
Patients are advised to be in complete bed rest for the first 24 hours. The dressing will be kept in place during this time. The patient’s head will be placed in an elevated position to reduce post-operative swelling. Adequate analgesia will be given to relieve post-procedural pain.
Post-operative nausea and vomiting may occur as side effects of general anaesthesia. Patients are encouraged to take fluids and appropriate diet as tolerated. Mild bleeding from the surgical site may occur. Compressive dressing and placement of cooling packs may be necessary. Swelling and bruising around the face is also expected in post-operative period and will usually resolve within the first week. Antibiotics may be prescribed when necessary to reduce wound infection. Patients are advised to keep the surgical wound clean and to apply antibiotic ointment. Removal of sutures may be done on post-operative day 5-10. The result of facelift will be visible after the swelling has subsided.
POST-OPERATIVE CARE
- Follow the postoperative instructions given carefully
- Head elevation especially when sleeping for 3-4 weeks
- Take the prescribed medications as instructed
- Cold compressive dressing around the lower jaw might be used for 3-7 days
- Regular mouth wash or gargle after every meal if there is any oral wounds
- Soft diet for 2-3 weeks
- Avoid strenuous physical activities for 3-4 weeks
– COPYRIGHT OF DR LEOW AIK MING
