Why Should I Extract My Wisdom Teeth

Everyday Practitioners and patients are torn with the decision of whether to extract impacted (wisdom) teeth ( why, when and by whom). These are teeth that are prevented from growing properly because of mechanical obstruction from adjacent tooth/teeth, bone or tumors. These entities, when present during the eruptive/growth phase (18-25 years), will adversely affect normal root and crown development.

Third molar impaction (wisdom teeth) is one of the most common dental procedure performed by Oral and Maxillofacial Surgeons. In 1977, seventy five to eighty eight percent of the total sum of 660 million dollars spent on oral surgical services was devoted to third molar removed. Whether these procedures were justified or not, the fact is that a significant amount of money was spent by insurance companies and out-of-pocket expenses in managing this particular problem.

The classification of impacted teeth depend on the orientation of teeth in the jaw and the depth of location. There are four types of impactions, based on the orientation of the teeth in the jaw: mesioangular, distoangular, horizontal and vertical. Mesioangular impactions are the most commonly impacted wisdom teeth. In this class, the teeth are leaning forward, most time, against the teeth in-front. Distoangular impactions are less common. They grow in the opposite direction. In both cases, the crown may be partially or completely submerged in bone. Horizontal impactions are teeth lying flat on the "stomach" with the crown and roots at the same depth within the jaw. And lastly, vertical impactions are teeth that grow upright with areas of bony obstruction on the crown.

Impacted teeth can also be classified based on the actual depth of the teeth in the jaw: soft tissue, partial bony and full bony impactions. Soft tissue impactions are almost completely erupted into the oral cavity, but the gingiva is covering part or the entire crown. Most patients with soft tissue impaction complain of the pain and inflammations of the gingiva: a condition called periconitis. Periconitis results from food trapped beneath the gingiva, creating an environment for bacterial growth and subsequently presenting with the above symptoms. When teeth that are partially bony impacted, the crown is partly submerged in the surrounding bone while fully impactions are completely covered by bone. The indications for extracting impacted teeth are numerous:

1. Approximately 30.6% patients complaining of problems with the impacted teeth have pain. Normally the intensity of the pain vary depending on the severity of the inflammation and surrounding bone pathology. On clinical examination the gingiva may appear eccthymotic (red), edematous (swollen) and tender. Other problems include repeated episodes of trismus (difficulty opening the mouth) which results from inflammation of the muscles of mastication. This entire group of disorders occurring together is called Periconitis. This occurs in approximately 32.7% of patients. Most invariably it results from local inflammation of the pericoronal tissue and trauma from the opposing tooth/teeth. Since this is the most common reason for extracting the wisdom teeth, it is important to understand that patients with periconitis be managed by qualified competent clinicians. Sometimes an infection in the area has a very strong potential for spreading into the surrounding areas to become a massive facial infection. Patients with theses infections are hospitalized for intravenous antibiotics and surgery. When necessary, other medical and surgical disciplines are consulted about proper management of orofacial infections. In rare cases, tracheotomy (surgical procedure that involves making a small hole in the neck/windpipe so that the patients can breath properly) is indicated to prevent respiratory embarrassment and death.

2. Pathology associated with the crown and roots of the impacted tooth. There is strong evidence that the pathology associated with impacted teeth can be a cyst, benign or malignant tumor. Benign lesions can become cancerous in some patients if not managed early. Also, there are rare cases where tumor can grow, causing expansion, destruction and injury to adjacent structures. In fact because of the extensive growth of these lesions, there are reported cases of spontaneous jaw fracture. Should biopsy report reveals that the existing pathology is cancerous, then more aggressive management are required, involving multiple disciplines (Head and neck surgeon Radiation therapist, Oral surgeon and Plastic surgeon).

3. Abnormal position of impacted tooth can affect eruption of adjacent tooth/teeth and at the same time create an unhealthy periodontal environment of the surrounding bony and soft tissue structures. It is shown that extraction of the impacted tooth will make sufficient space for unobstructed eruption of tooth/teeth and enhance proper daily cleansing.

4. Tooth/ teeth in the line of fracture or at the site of osseous defect(s) that may affect satisfactory healing or function. Most fractures involving the posterior mandible are intimately involved with the mesial (front) or distal (back) surfaces of impacted teeth. The same thing is true of other areas of the jaw where fully erupted teeth exist. This is because of the relative thickness of the bone in the area. Hence it is recommended that teeth in compromised areas of fractures or defects be extracted to avoid infection and subsequently decreased dental function.

5. For orthodontic reasons because of the need for additional space to move existing mal-positioned teeth into proper alignment. Many patients requiring orthodontic treatment have relatively small arches in the upper and lower jaws which ultimately affect the eruption of permanent teeth. Therefore severe crowding of the mandibular teeth may result. Extractions are indicated to create ‘room’ for proper alignment of remaining teeth and remove anterior forces placed by the impacted teeth on remaining teeth.

6. Prophylactically, extractions are indicated in anticipation for long-term medical or surgical therapy. Because of the periodic inflammation and potential infections that are associated with impacted teeth, it is strongly recommended that they be extracted in preparation for treatment chemotherapy and/or major surgery. This is particularly important in patients having organ transplant, chemotherapy, radiation therapy, valvular heart disease(s) and compromised immune system, where periodic infections of unknown origins present a challenge for complete and satisfactory recovery of these special patients.

Any licensed dentist who is trained and qualified in the removal of impactions can perform this type of surgery. However, an Oral Surgeon is a dentist who specializes in the management of intricate and detailed procedures of the oral cavity. They are the most qualified clinician recommended to remove impacted teeth.

Before surgery is performed, the risks and complications must be clearly explained and understood detailing the extensiveness of the surgery, associated areas of potential injury and alternative care available. These complications include injury to the nerves (inferior alveolar and lingual nerves) 0.6-5% of the time. The neurological damage presents as numbness, of varying degree, depending on the extent and type of the injury. Some may appear as a slight alteration in sensation (ability to feel), to a profound or total loss of all sensations. Injury involving the inferior alveolar nerve and lingual nerve recover spontaneously 96% and 87% respectively. If there is no change in feeling during a six to twelve month period, then considerations should be given for additional surgery or nerve grafting ( procedure where nerve is taken from one part of the body and transplanted to the abnormal, injured area. This aids in the partial or complete return of normal sensation). Most nerve injury occurs when there is an intimate relationship between the nerve and roots of the tooth being extracted.

Other complications include alveolar osteitis (dry socket), infections, pain, swelling, fracture of the jaw, displacement or damage of the adjacent teeth, trismus (difficulty opening the mouth). The frequency of alveolar osteitis is up to 37%. Generally the symptoms start about 3-5 days after surgery as severe radiating throbbing pain at the extraction site and the ear (giving the impression of an ear infection) sometimes not relieved by pain medication (if so for a short period), foul taste and odor and localized soft tissue inflammation. Some of the most common causes include surgical trauma, inadequate blood supply, preexisting infection, increased bone density. Also the use of local anesthetic agents at the extraction site, varying oral flora, disintegration of the organized clot. Some researchers have reported, that in some patients the age (older) and sex (women who use oral contraceptive) are contributing factors.

To a lesser extent oral surgical patients may suffer from oroantral or oronasal fistula (communication between the oral cavity and the maxillary sinus and the oral cavity and the nose through a small hole in the extraction site) and disorders of the Temporomandibular joint and muscles of mastication.

Although these are some of the most common problems reported by patients, other adverse reactions do occur. It is best that these be discussed before final decision for surgery be made.

There are many reasons for extracting impacted teeth, however should be discussed with a competent surgeon before operative procedure are decided. If your dentist says during the next oral examination that ‘the impacted tooth should not be extracted because it does not bother you’, plans should be made for a more thorough consultation with a more competent practitioner.

-- Rawle F. Philbert, DDS