Extraction
A dental extraction (also referred to as tooth extraction, exodontia, exodontics, or informally, tooth pulling) is the removal of teeth from the dental alveolus (socket) in the alveolar bone. Extractions are performed for a wide variety of reasons, but most commonly to remove teeth which have becomeunrestorable through tooth decay, periodontal disease or dental trauma, especially when they are associated with toothache. Sometimes wisdom teeth are impacted (stuck and unable to grow normally into the mouth) and may cause recurrent infections of the gum (pericoronitis). In orthodontics if the teeth arecrowded, sound teeth may be extracted (often bicuspids) to create space so the rest of the teeth can be straightened.
Tooth extraction is usually relatively straightforward, and the vast majority can be usually performed quickly while the individual is awake by using local anesthetic injections to eliminate painful sensations. Local anesthetic blocks pain, but mechanical forces are still vaguely felt. Some teeth are more difficult to remove for several reasons, especially related to the tooth’s position, the shape of the tooth roots and the integrity of the tooth. Dental phobia is an issue for some individuals, and tooth extraction tends to be feared more than other dental treatments like fillings. If a tooth is buried in the bone, a surgical or trans alveolar approach may be required, which involves cutting the gum away and removal of the bone which is holding the tooth in with a surgical drill. After the tooth is removed, stitches are used to replace the gum into the normal position.
Immediately after the tooth is removed, a bite pack is used to apply pressure to the tooth socket and stop the bleeding. After a tooth extraction, dentists usually give advice which revolves around not disturbing the blood clot in the socket by not touching the area with a finger or the tongue, by avoiding vigorous rinsing of the mouth and avoiding strenuous activity. Sucking, such as through a straw, is to be avoided. If the blood clot is dislodged, bleeding can restart, or alveolar osteitis (“dry socket”) can develop, which can be very painful and lead to delayed healing of the socket. Smoking is avoided for at least 24 hours as it impairs wound healing and makes dry socket significantly more likely. Most advise hot salt water mouth baths which start 24 hours after the extraction.
The branch of dentistry that deals primarily with extractions is oral surgery (“exodontistry”), although general dentists and clinicians from other dental specialties may also carry out tooth extraction routinely since it is a core skill taught in dental schools.
Reasons
The most common reason for extraction is tooth damage due to breakage or decay. There are additional reasons for tooth extraction:
Severe tooth decay or infection (acute or chronic alveolar abscess). Despite the reduction in worldwide prevalence of dental caries, it is still the most common reason for extraction of (non-third molar) teeth with up to two thirds of extractions.
Supernumerary teeth which are blocking other teeth from coming in.
Severe gum disease which may affect the supporting tissues and bone structures of teeth.
In preparation for orthodontic treatment (braces)
Teeth in the fracture line
Teeth which cannot be restored endodontically
Fractured teeth
Supernumerary, supplementary or malformed teeth
Prosthetics; teeth detrimental to the fit or appearance of dentures
Treatment of symptomatic impacted wisdom teeth, whose impaction is causing pathosis that will lead to yet more (infection, inflammation, bone resorption)
Preventive/prophylactic removal of asymptomatic impacted wisdom teeth. Although many dentists remove asymptomatic impacted third molars, both American and British Health Authorities recommend against this routine procedure, unless there is evidence for disease in the impacted tooth or the near environment. The American Public Health Association, for example, adopted a policy, Opposition to Prophylactic Removal of Third Molars (Wisdom Teeth), because of the large number of injuries resulting from unnecessary extractions.
Cosmetic; teeth of poor appearance, unsuitable for restoration
Receiving radiation therapy to the head and neck area may require extraction of teeth in the field of radiation.
Deliberate, medically unnecessary, extraction as a form of physical torture.
It was once a common practice to remove the front teeth of institutionalized psychiatric patients who had a history of biting.
Reduced cost compared to other treatments.
Types
Extractions are often categorized as “simple” or “surgical”.
Simple extractions are performed on teeth that are visible in the mouth, usually under local anaesthetic, and require only the use of instruments to elevate and/or grasp the visible portion of the tooth. Typically the tooth is lifted using an elevator, and using dental forceps, rocked back and forth until the periodontal ligament has been sufficiently broken and the supporting alveolar bone has been adequately widened to make the tooth loose enough to remove. Typically, when teeth are removed with forceps, slow, steady pressure is applied with controlled force.
Surgical extractions involve the removal of teeth that cannot be easily accessed, either because they have broken under the gum line or because they have not erupted fully. Surgical extractions almost always require an incision. In a surgical extraction the doctor may elevate the soft tissues covering the tooth and bone and may also remove some of the overlying and/or surrounding jawbone tissue with a drill or osteotome. Frequently, the tooth may be split into multiple pieces to facilitate its removal. Surgical extractions are usually performed under a general anaesthetic.
Anticoagulant use
Patients utilizing long-term anticoagulant therapies such as warfarin or salicylic acid do not need to discontinue its use prior to having a tooth extracted. The extraction should be performed utilizing the least traumatic extraction procedures. As such, patients should make sure to tell their dentist or oral surgeon about any medications they may take before the procedure.
Antibiotic use
Antibiotics can be prescribed by dental professionals to reduce risks of certain post extraction complications. There is evidence that use of antibiotics before and/or after impacted wisdom tooth extraction reduces the risk of infections by 70% and lowers incidence of dry socket by one third. For every 12 people who are treated with an antibiotic following impacted wisdom tooth removal, one infection is prevented. Use of antibiotics does not seem to have a direct effect on manifestation of fever, swelling or trismus seven days post-extraction. In the 2013 Cochrane review, 18 randomized control double-blinded experiments were reviewed and after considering the biased risk associated with these studies, it was concluded that there is moderate overall evidence supporting the routine use of antibiotics in practice in order to reduce risk of infection following a third molar extraction. There are still reasonable concerns remaining regarding the possible adverse effects of indiscriminate antibiotic use in patients. There are also concerns about development of antibiotic resistance which advises against the use of prophylactic antibiotics in practice.
Post-extraction healing
Immediately following the removal of a tooth, bleeding or just oozing very commonly occurs. Pressure is applied by biting on a gauze swab, and a thrombus (blood clot) forms in the socket (hemostatic response). Sometimes 30 minutes of continuous pressure is required to fully arrest bleeding. Talking, which moves the mandible and hence removes the pressure applied on the socket, instead of keeping constant pressure, is a very common reason that bleeding might not stop. This is likened to someone with a bleeding wound on their arm, when being instructed to apply pressure, instead holds the wound intermittently every few moments. Coagulopathies(clotting disorders, e.g. hemophilia) are sometimes discovered for the first time if a person has had no other surgical procedure in their life, but this is rare. Sometimes the blood clot can be dislodged, triggering more bleeding and formation of a new blood clot, or leading to a dry socket (see complications). Some oral surgeons routinely scrape the walls of a socket to encourage bleeding in the belief that this will reduce the chance of dry socket, but there is no evidence that this practice works.
The chance of further bleeding reduces as healing progresses, and is unlikely after 24 hours. The blood clot is covered by epithelial cells which proliferate from the gingival mucosa of socket margins, taking about 10 days to fully cover the defect. In the clot, neutrophils and macrophages are involved as an inflammatory response takes place. The proliferative and synthesizing phase next occurs, characterized by proliferation of osteogenic cells from the adjacent bone marrow in the alveolar bone. Bone formation starts after about 10 days from when the tooth was extracted. After 10–12 weeks, the outline of the socket is no longer apparent on an X-ray image. Bony remodeling as the alveolus adapts to the edentulous state occurs in the longer term as the alveolar process slowly resorbs. In maxillary posterior teeth, the degree of pneumatization of the maxillary sinus may also increase as the antral floor remodels.