Dental extraction

A dental extraction is the removal of teeth from the dental alveolus in the alveolar bone. Extractions are performed for a wide variety of reasons, but most commonly to remove teeth which have become unrestorable through tooth decay, periodontal disease, or dental trauma, especially when they are associated with toothache. Sometimes impacted wisdom teeth cause recurrent infections of the gum, and may be removed when other conservative treatments have failed. In orthodontics, if the teeth are crowded, healthy teeth may be extracted to create space so the rest of the teeth can be straightened.

Procedure

Extractions could be categorized into non-surgical and surgical, depending on the type of tooth to be removed and other factors.

Assessment and special investigations

A comprehensive history taking should be performed to find out the pain history of the tooth, the patient's medical history and the history of previous difficult extractions. The tooth should be assessed clinically i.e. checked visually by the dentist. Pre-extraction radiographs are not always necessary but are often taken to confirm the diagnosis and hence appropriate treatment plan. Radiographs also help in visualising the shape and size of roots which are beneficial in planning the extraction. All this information will aid the dentist in foreseeing any difficulties and hence preparing appropriately.

Obtaining consent from patient

In order to obtain permission from patient for extraction of tooth, the dentist should explain that other treatment options are available, what is involved in the dental extraction procedure, the potential risks of the procedure and the benefits of the procedure. The process of gaining consent should be documented in clinical notes.

Giving local anaesthetic

Before extracting a tooth, the dentist would deliver local anaesthetic to ensure the tooth and surrounding tissues are numb before they start the extraction. There are several techniques to achieve numbness of the tooth including

infiltration – injection containing local anaesthetic is delivered into the gum near the root tip of the tooth to be extracted. This allows the local anaesthetic to penetrate through the bone, eventually reaching the nerve bundle of the tooth to be extracted.
nerve block – injection containing local anaesthetic is delivered to an earlier branch of a nerve. For example, the inferior alveolar nerve block can be used to anaesthetise all the lower teeth.

The two most commonly used local anaesthetics in the UK are lidocaine and articaine. Prior to injection, topical anaesthetic gel or cream, such as lidocaine or benzocaine, can be applied to the gum to numb the site of the injection up to a few millimetres deep. This should reduce the discomfort felt during the injection and thus help to reduce patient anxiety.

Removal of tooth

During extraction, multiple instruments are used to aid and ease the removal of the tooth whilst trying to minimally traumatise the tissues to allow for quicker healing.
Extraction forceps are commonly used to remove teeth. Different shaped forceps are available depending on the type of tooth requiring removal, what side of the mouth it is on and if it is an upper or lower tooth. The beaks of the forceps must grip onto the root of the tooth securely before pressure is applied along the long axis of the tooth towards the root.
Different movements of the forceps can be employed to remove teeth. Generally, while keeping downwards pressure attempts to move the tooth towards the cheek side and then the opposite direction are made to loosen the tooth from its socket. For single, conical-rooted teeth such as the incisors, rotatory movements are also used. A 'figure of eight' movement can be used to extract lower molars.
Instruments used are summarised below:

Name	Type of instrument	Use	Area of use	Unique features
Luxator	Luxator	Tear PDL around tooth	Anywhere	Sharp blade
Coupland	Elevator	expand socket and lift	Anywhere	Numbered 1–3 from most narrow to wide
Warrick James	Elevator	Expand socket and lift tooth	Anywhere	Right left and straight
Cryers	Elevator	Expand socket and lift tooth	Anywhere	Right and left with sharp tips
Upper straight	Forcep	Remove teeth	Upper canine to canine	Straight handle
Upper anterior	Forcep	Remove teeth	Upper anteriors and premolars
Upper molar	Forcep	Remove teeth	Upper 1st/2nd/3rd molars	One pointed end to engage buccal furcation
Upper bayonet	Forcep	Remove teeth	Upper 3rd molars	Curved handle and tip to reach 3rd molars
Upper root	Forcep	Remove teeth	Upper retained/fractured roots	Narrow tips
Cowhorn	Forcep	Remove teeth	Lower molars	Thin tips to engage furcation of broken down molars
Lower anterior	Forcep	Remove teeth	Lower anteriors and premolars	90 degree bend handle
lower molar	Forcep	Remove teeth	Lower 1st/2nd/3rd molars	2 beak tips to engage furcations
Lower root	Forcep	Remove teeth	Lower retained/fractured roots	Narrow tips to engage roots

In terms of operator positioning when removing a tooth, the patient is placed more supine when extracting an upper and more upright when extracting a lower. This is to allow direct vision for the operator during the procedure. A right handed operator will stand to the front of the patient and to their right when removing any upper teeth or lower left teeth. However, they will stand behind the patient and to the right when extracting a lower right tooth.
Dental elevators can be used to aid removal of teeth. Various types are available that have different shapes. Their working ends are designed to engage into the space between the tooth and bone of the socket. Rotatory movements are then made to dislodge the tooth from the socket. Another similar looking but sharper instrument that can be used is a luxator; this instrument can be used gently and with great care to cut the ligament between the tooth and its boney socket.

Achieving haemostasis">Hemostasis">haemostasis

Biting down on a piece of sterile gauze over the socket will provide firm pressure to the wound. Normally this is sufficient to stop any bleeding and will promote blood clot formation at the base of the socket.
Moreover, the patient must be inhibited from eating and drinking hot food in the first 24 hours. Using straw for drinking is also prohibited due to the negative pressure it can produce which will lead to removal of a newly formed clot from the socket.
The source of any bleeding can either be from soft tissues or hard tissue. Bleeding of soft tissues can be controlled by several means including suturing the wound and/ or using chemical agents such as tranexamic acid, ferric sulphate and silver nitrate. Bony bleeding can be arrested by using haemostatic gauze and bone wax. Other means of achieving haemostasis include electrocautery.

Reasons

Medical/Dental

Severe tooth decay or infection. Despite the reduction in worldwide prevalence of dental caries, it is still the most common reason for extraction of teeth, accounting for up to two thirds of extractions.
Severe gum disease, which may affect the supporting tissues and bone structures of teeth.
Treatment of symptomatic impacted wisdom teeth e.g. that are associated with pericoronitis, unrestorable caries or cysts.
Prophylactic removal of asymptomatic impacted wisdom teeth. Historically, many asymptomatic impacted third molars were removed, however, both American and British Health Authorities now provide guidance about the indication for third molar removal. The American Public Health Association, for example, adopted a policy, Opposition to Prophylactic Removal of Third Molars, because of the large number of injuries resulting from unnecessary extractions.
Supernumerary teeth that are blocking other teeth from coming in.
Supplementary or malformed teeth.
Fractured teeth.
Teeth in the fracture line of the jaw bone
Teeth which cannot be restored endodontically.
Prosthetics; teeth detrimental to the fit or appearance of dentures.
Head and neck radiation therapy, to treat and/or manage tumors, may require extraction of teeth, either before or after radiation treatments.
Lower cost, compared to other treatments.
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.

Orthodontic

In preparation for orthodontic treatment. Extractions are commonly required before the provision of orthodontic treatment, to create space for crowded teeth to be moved into. The premolar teeth are the most commonly extracted teeth for this purpose.

Aesthetics

Cosmetic: to remove teeth of poor appearance, unsuitable for restoration.
Types

Extractions are often categorized as "simple" or "surgical".
Simple extractions are performed on teeth that are visible in the mouth, usually with the patient 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, specific tooth movements are performed expanding the tooth socket. Once the periodontal ligament is broken and the supporting alveolar bone has been adequately widened the tooth can be removed. 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 or removed via simple extraction, for example because they have broken under the gum or because they have not erupted fully, such as an impacted wisdom tooth. Surgical extractions almost always require an incision. In a surgical extraction the dentist may elevate the soft tissues covering the tooth and bone, and may also remove some of the overlying and/or surrounding jaw bone with a drill or, less commonly, an instrument called an osteotome. Frequently, the tooth may be split into multiple pieces to facilitate its removal.
Common risks after any extraction include pain, swelling, bleeding, bruising, infection, trismus and dry socket. There are additional risks associated with the surgical extraction of wisdom teeth in particular: permanent or temporary damage to the inferior alveolar nerve +/− lingual nerve, causing permanent or temporary numbness, tingling or altered sensation to the lip, chin +/− tongue.