Toothache

The majority of pulpal toothache falls into one of the following types; however, other rare causes (which do not always fit neatly into these categories) include galvanic pain and barodontalgia.

Pulpitis (inflammation of the pulp) can be triggered by various stimuli (insults), including mechanical, thermal, chemical, and bacterial irritants, or rarely barometric changes and ionizing radiation.[14] Common causes include tooth decay, dental trauma (such as a crack or fracture), or a filling with an imperfect seal.

Because the pulp is encased in a rigid outer shell, there is no space to accommodate swelling caused by inflammation. Inflammation therefore increases pressure in the pulp system, potentially compressing the blood vessels which supply the pulp. This may lead to ischemia (lack of oxygen) and necrosis (tissue death). Pulpitis is termed reversible when the inflamed pulp is capable of returning to a state of health, and irreversible when pulp necrosis is inevitable.[10]^: 36–37

Reversible pulpitis is characterized by short-lasting pain triggered by cold and sometimes heat.[12] The symptoms of reversible pulpitis may disappear, either because the noxious stimulus is removed, such as when dental decay is removed and a filling placed, or because new layers of dentin (tertiary dentin) have been produced inside the pulp chamber, insulating against the stimulus. Irreversible pulpitis causes spontaneous or lingering pain in response to cold.[15]^{: 619–627}

Dentin hypersensitivity is a sharp, short-lasting dental pain occurring in about 15% of the population,[16] which is triggered by cold (such as liquids or air), sweet or spicy foods, and beverages.[17] Teeth will normally have some sensation to these triggers,[18] but what separates hypersensitivity from regular tooth sensation is the intensity of the pain. Hypersensitivity is most commonly caused by a lack of insulation from the triggers in the mouth due to gingival recession (receding gums) exposing the roots of the teeth, although it can occur after scaling and root planing or dental bleaching, or as a result of erosion.[19] The pulp of the tooth remains normal and healthy in dentin hypersensitivity.[10]^: 510

Many topical treatments for dentin hypersensitivity are available, including desensitizing toothpastes and protective varnishes that coat the exposed dentin surface.[16] Treatment of the root cause is critical, as topical measures are typically short lasting.[10]^: 510 Over time, the pulp usually adapts by producing new layers of dentin inside the pulp chamber called tertiary dentin, increasing the thickness between the pulp and the exposed dentin surface and lessening the hypersensitivity.[10]^: 510

In general, chronic periodontal conditions do not cause any pain. Rather, it is acute inflammation which is responsible for the pain.[18]

Apical abscess associated with roots of a lower molar.

Apical periodontitis is acute or chronic inflammation around the apex of a tooth caused by an immune response to bacteria within an infected pulp.[20] It does not occur because of pulp necrosis, meaning that a tooth that tests as if it's alive (vital) may cause apical periodontitis, and a pulp which has become non-vital due to a sterile, non-infectious processes (such as trauma) may not cause any apical periodontitis.[10]^: 225 Bacterial cytotoxins reach the region around the roots of the tooth via the apical foramina and lateral canals, causing vasodilation, sensitization of nerves, osteolysis (bone resorption) and potentially abscess or cyst formation.[10]^: 228

The periodontal ligament becomes inflamed and there may be pain when biting or tapping on the tooth. On an X-ray, bone resorption appears as a radiolucent area around the end of the root, although this does not manifest immediately.[10]^: 228 Acute apical periodontitis is characterized by well-localized, spontaneous, persistent, moderate to severe pain.[6]^{: 125–135} The alveolar process may be tender to palpation over the roots. The tooth may be raised in the socket and feel more prominent than the adjacent teeth.[6]^{: 125–135}

An open contact of approximately 1.5 mm shown between two posterior teeth. The meat, at right, was recovered from the open contact more than 8 hours after the person had last eaten meat, even though they had brushed the teeth twice since.

Food impaction occurs when food debris, especially fibrous food such as meat, becomes trapped between two teeth and is pushed into the gums during chewing.[6]^{: 125–135} The usual cause of food impaction is disruption of the normal interproximal contour or drifting of teeth so that a gap is created (an open contact). Decay can lead to collapse of part of the tooth, or a dental restoration may not accurately reproduce the contact point. Irritation, localized discomfort or mild pain and a feeling of pressure from between the two teeth results. The gingival papilla is swollen, tender and bleeds when touched. The pain occurs during and after eating, and may slowly disappear before being evoked again at the next meal,[nb 1] or relieved immediately by using a tooth pick or dental floss in the involved area.[6]^{: 125–135} A gingival or periodontal abscess may develop from this situation.[21]^{: 444–445}

Lateral periodontal abscess (blue arrows) due to a fracture (green arrows)

A periodontal abscess (lateral abscess) is a collection of pus that forms in the gingival crevices, usually as a result of chronic periodontitis where the pockets are pathologically deepened greater than 3mm. A healthy gingival pocket will contain bacteria and some calculus kept in check by the immune system. As the pocket deepens, the balance is disrupted, and an acute inflammatory response results, forming pus. The debris and swelling then disrupt the normal flow of fluids into and out of the pocket, rapidly accelerating the inflammatory cycle. Larger pockets also have a greater likelihood of collecting food debris, creating additional sources of infection.[21]^: 443

Periodontal abscesses are less common than apical abscesses, but are still frequent. The key difference between the two is that the pulp of the tooth tends to be alive, and will respond normally to pulp tests. However, an untreated periodontal abscess may still cause the pulp to die if it reaches the tooth apex in a periodontic-endodontic lesion. A periodontal abscess can occur as the result of tooth fracture, food packing into a periodontal pocket (with poorly shaped fillings), calculus build-up, and lowered immune responses (such as in diabetes). Periodontal abscess can also occur after periodontal scaling, which causes the gums to tighten around the teeth and trap debris in the pocket.[21]^{: 444–445} Toothache caused by a periodontal abscess is generally deep and throbbing. The oral mucosa covering an early periodontal abscess appears erythematous (red), swollen, shiny, and painful to touch.[22]

A variant of the periodontal abscess is the gingival abscess, which is limited to the gingival margin, has a quicker onset, and is typically caused by trauma from items such as a fishbone, toothpick, or toothbrush, rather than chronic periodontitis.[21]^{: 446–447} The treatment of a periodontal abscess is similar to the management of dental abscesses in general (see: Treatment). However, since the tooth is typically alive, there is no difficulty in accessing the source of infection and, therefore, antibiotics are more routinely used in conjunction with scaling and root planing.[23] The occurrence of a periodontal abscess usually indicates advanced periodontal disease, which requires correct management to prevent recurrent abscesses, including daily cleaning below the gumline to prevent the buildup of subgingival plaque and calculus.

Mild presentation of ANUG on the gums of the lower front teeth

Common marginal gingivitis in response to subgingival plaque is usually a painless condition. However, an acute form of gingivitis/periodontitis, termed acute necrotizing ulcerative gingivitis (ANUG), can develop, often suddenly. It is associated with severe periodontal pain, bleeding gums, "punched out" ulceration, loss of the interdental papillae, and possibly also halitosis (bad breath) and a bad taste. Predisposing factors include poor oral hygiene, smoking, malnutrition, psychological stress, and immunosuppression.[21]^: 97–98 This condition is not contagious, but multiple cases may simultaneously occur in populations who share the same risk factors (such as students in a dormitory during a period of examination).[24] ANUG is treated over several visits, first with debridement of the necrotic gingiva, homecare with hydrogen peroxide mouthwash, analgesics and, when the pain has subsided sufficiently, cleaning below the gumline, both professionally and at home. Antibiotics are not indicated in ANUG management unless there is underlying systemic disease.[21]^{: 437–438}

Clinical & xray correlation of pericoronitis

An operculum (green arrow) over a partially erupted lower left third molar tooth. There is minimal inflammation and recurrent swelling.

A radiograph of the above tooth showing chronic pericoronitis, operculum (blue arrow) and bone destruction (red arrow) from chronic inflammation. Tooth is slightly disto-angular.

Pericoronitis is inflammation of the soft tissues surrounding the crown of a partially erupted tooth.[25] The lower wisdom tooth is the last tooth to erupt into the mouth, and is, therefore, more frequently impacted, or stuck, against the other teeth. This leaves the tooth partially erupted into the mouth, and there frequently is a flap of gum (an operculum), overlying the tooth. Bacteria and food debris accumulate beneath the operculum, which is an area that is difficult to keep clean because it is hidden and far back in the mouth. The opposing upper wisdom tooth also tends to have sharp cusps and over-erupt because it has no opposing tooth to bite into, and instead traumatizes the operculum further. Periodontitis and dental caries may develop on either the third or second molars, and chronic inflammation develops in the soft tissues. Chronic pericoronitis may not cause any pain, but an acute pericoronitis episode is often associated with pericoronal abscess formation. Typical signs and symptoms of a pericoronal abscess include severe, throbbing pain, which may radiate to adjacent areas in the head and neck,[21][26]^: 122 redness, swelling and tenderness of the gum over the tooth.[27]^{: 220–222} There may be trismus (difficulty opening the mouth),[27]^{: 220–222} facial swelling, and rubor (flushing) of the cheek that overlies the angle of the jaw.[21][26]^: 122 Persons typically develop pericoronitis in their late teens and early 20s,[28]^: 6 as this is the age that the wisdom teeth are erupting. Treatment for acute conditions includes cleaning the area under the operculum with an antiseptic solution, painkillers, and antibiotics if indicated. After the acute episode has been controlled, the definitive treatment is usually by tooth extraction or, less commonly, the soft tissue is removed (operculectomy). If the tooth is kept, good oral hygiene is required to keep the area free of debris to prevent recurrence of the infection.[21]^{: 440–441}

Occlusal trauma results from excessive biting forces exerted on teeth, which overloads the periodontal ligament, causing periodontal pain and a reversible increase in tooth mobility. Occlusal trauma may occur with bruxism, the parafunctional (abnormal) clenching and grinding of teeth during sleep or while awake. Over time, there may be attrition (tooth wear), which may also cause dentin hypersensitivity, and possibly formation of a periodontal abscess, as the occlusal trauma causes adaptive changes in the alveolar bone.[21]^{: 153–154}

Occlusal trauma often occurs when a newly placed dental restoration is built too "high", concentrating the biting forces on one tooth. Height differences measuring less than a millimeter can cause pain. Dentists, therefore, routinely check that any new restoration is in harmony with the bite and forces are distributed correctly over many teeth using articulating paper. If the high spot is quickly eliminated, the pain disappears and there is no permanent harm.[21]^{: 153, 753} Over-tightening of braces can cause periodontal pain and, occasionally, a periodontal abscess.[21]^: 503

Alveolar osteitis is a complication of tooth extraction (especially lower wisdom teeth) in which the blood clot is not formed or is lost, leaving the socket where the tooth used to be empty, and bare bone is exposed to the mouth.[29] The pain is moderate to severe, and dull, aching, and throbbing in character. The pain is localized to the socket, and may radiate. It normally starts two to four days after the extraction, and may last 10–40 days.[14][26]^: 122[27]^{: 216–217}[29] Healing is delayed, and it is treated with local anesthetic dressings, which are typically required for five to seven days.[27]^{: 216–217} There is some evidence that chlorhexidine mouthwash used prior to extractions prevents alveolar osteitis.[29]

Crown-root fracture with pulp involvement (left). Extracted (right).

Cracked tooth syndrome refers to a highly variable[30] set of pain-sensitivity symptoms that may accompany a tooth fracture, usually sporadic, sharp pain that occurs during biting or with release of biting pressure,[31] or relieved by releasing pressure on the tooth.[10]^: 24 The term is falling into disfavor and has given way to the more generalized description of fractures and cracks of the tooth, which allows for the wide variations in signs, symptoms, and prognosis for traumatized teeth. A fracture of a tooth can involve the enamel, dentin, and/or pulp, and can be orientated horizontally or vertically.[10]^: 24–25 Fractured or cracked teeth can cause pain via several mechanisms, including dentin hypersensitivity, pulpitis (reversible or irreversible), or periodontal pain. Accordingly, there is no single test or combination of symptoms that accurately diagnose a fracture or crack, although when pain can be stimulated by causing separation of the cusps of the tooth, it's highly suggestive of the disorder.[10]^: 27–31 Vertical fractures can be very difficult to identify because the crack can rarely be probed[10]^: 27 or seen on radiographs, as the fracture runs in the plane of conventional films (similar to how the split between two adjacent panes of glass is invisible when facing them).[10]^: 28–9

When toothache results from dental trauma (regardless of the exact pulpal or periodontal diagnosis), the treatment and prognosis is dependent on the extent of damage to the tooth, the stage of development of the tooth, the degree of displacement or, when the tooth is avulsed, the time out of the socket and the starting health of the tooth and bone. Because of the high variation in treatment and prognosis, dentists often use trauma guides to help determine prognosis and direct treatment decisions.[32][33]

The prognosis for a cracked tooth varies with the extent of the fracture. Those cracks that are irritating the pulp but do not extend through the pulp chamber can be amenable to stabilizing dental restorations such as a crown or composite resin. Should the fracture extend though the pulp chamber and into the root, the prognosis of the tooth is hopeless.[10]^: 25

Apical abscesses can spread to involve periodontal pockets around a tooth, and periodontal pockets cause eventual pulp necrosis via accessory canals or the apical foramen at the bottom of the tooth. Such lesions are termed periodontic-endodontic lesions, and they may be acutely painful, sharing similar signs and symptoms with a periodontal abscess, or they may cause mild pain or no pain at all if they are chronic and free-draining.[34] Successful root canal therapy is required before periodontal treatment is attempted.[21]^: 49 Generally, the long-term prognosis of perio-endo lesions is poor.

Discomfort caused by coronary artery disease can radiate to the neck, lower jaw and teeth

Non-dental causes of toothache are much less common as compared with dental causes. In a toothache of neurovascular origin, pain is reported in the teeth in conjunction with a migraine. Local and distant structures (such as ear, brain, carotid artery, or heart) can also refer pain to the teeth.[35]^: 80, 81 Other non-dental causes of toothache include myofascial pain (muscle pain) and angina pectoris (which classically refers pain to the lower jaw). Very rarely, toothache can be psychogenic in origin.[10]^: 57–58

Disorders of the maxillary sinus can be referred to the upper back teeth. The posterior, middle and anterior superior alveolar nerves are all closely associated with the lining of the sinus. The bone between the floor of the maxillary sinus and the roots of the upper back teeth is very thin, and frequently the apices of these teeth disrupt the contour of the sinus floor. Consequently, acute or chronic maxillary sinusitis can be perceived as maxillary toothache,[36] and neoplasms of the sinus (such as adenoid cystic carcinoma)[37]^: 390 can cause similarly perceived toothache if malignant invasion of the superior alveolar nerves occurs.[38]^: 72 Classically, sinusitis pain increases upon Valsalva maneuvers or tilting the head forward.[39]

Painful conditions which do not originate from the teeth or their supporting structures may affect the oral mucosa of the gums and be interpreted by the individual as toothache. Examples include neoplasms of the gingival or alveolar mucosa (usually squamous cell carcinoma),[37]^: 299 conditions which cause gingivostomatitis and desquamative gingivitis. Various conditions may involve the alveolar bone, and cause non-odontogenic toothache, such as Burkitt's lymphoma,[38]^: 340 infarcts in the jaws caused by sickle cell disease,[40]^: 214 and osteomyelitis.[41]^: 497 Various conditions of the trigeminal nerve can masquerade as toothache, including trigeminal zoster (maxillary or mandibular division),[40]^: 487 trigeminal neuralgia,[36] cluster headache,[36] and trigeminal neuropathies.[36] Very rarely, a brain tumor might cause toothache.[35]^: 80, 81 Another chronic facial pain syndrome which can mimic toothache is temporomandibular disorder (temporomandibular joint pain-dysfunction syndrome),[36] which is very common. Toothache which has no identifiable dental or medical cause is often termed atypical odontalgia, which, in turn, is usually considered a type of atypical facial pain (or persistent idiopathic facial pain).[36] Atypical odontalgia may give very unusual symptoms, such as pain which migrates from one tooth to another and which crosses anatomical boundaries (such as from the left teeth to the right teeth).

The chief complaint, and the onset of the complaint, are usually important in the diagnosis of toothache. For example, the key distinction between reversible and irreversible pulpitis is given in the history, such as pain following a stimulus in the former, and lingering pain following a stimulus and spontaneous pain in the latter. History is also important in recent filling or other dental treatment, and trauma to the teeth. Based on the most common causes of toothache (dentin hypersensitivity, periodontitis, and pulpitis), the key indicators become localization of the pain (whether the pain is perceived as originating in a specific tooth), thermal sensitivity, pain on biting, spontaneity of the pain, and factors that make the pain worse.[10]^: 50The various qualities of the toothache, such as the effect of biting and chewing on the pain, the effect of thermal stimuli, and the effect of the pain on sleep, are verbally established by the clinician, usually in a systematic fashion, such as using the Socrates pain assessment method (see table).[10]^: 2–9

From the history, indicators of pulpal, periodontal, a combination of both, or non-dental causes can be observed. Periodontal pain is frequently localized to a particular tooth, which is made much worse by biting on the tooth, sudden in onset, and associated with bleeding and pain when brushing. More than one factor may be involved in the toothache. For example, a pulpal abscess (which is typically severe, spontaneous and localized) can cause periapical periodontitis (which results in pain on biting). Cracked tooth syndrome may also cause a combination of symptoms. Lateral periodontitis (which is usually without any thermal sensitivity and sensitive to biting) can cause pulpitis and the tooth becomes sensitive to cold.[10]^: 2–9

Non-dental sources of pain often cause multiple teeth to hurt and have an epicenter that is either above or below the jaws. For instance, cardiac pain (which can make the bottom teeth hurt) usually radiates up from the chest and neck, and sinusitis (which can make the back top teeth hurt) is worsened by bending over.[10]^: 56, 61 As all of these conditions may mimic toothache, it is possible that dental treatment, such as fillings, root canal treatment, or tooth extraction may be carried out unnecessarily by dentists in an attempt to relieve the individual's pain, and as a result the correct diagnosis is delayed. A hallmark is that there is no obvious dental cause, and signs and symptoms elsewhere in the body may be present. As migraines are typically present for many years, the diagnosis is easier to make. Often the character of the pain is the differentiator between dental and non-dental pain.

Irreversible pulpitis progresses to pulp necrosis, wherein the nerves are non-functional, and a pain-free period following the severe pain of irreversible pulpitis may be experienced. However, it is common for irreversible pulpitis to progress to apical periodontitis, including an acute apical abscess, without treatment. As irreversible pulpitis generates an apical abscess, the character of the toothache may simply change without any pain-free period. For instance, the pain becomes well localized, and biting on the tooth becomes painful. Hot drinks can make the tooth feel worse because they expand the gases and likewise, cold can make it feel better, thus some will sip cold water.[10][14]

The clinical examination narrows the source down to a specific tooth, teeth, or a non-dental cause. Clinical examination moves from the outside to the inside, and from the general to the specific. Outside of the mouth, the sinuses, muscles of the face and neck, the temporomandibular joints, and cervical lymph nodes are palpated for pain or swelling.[10]^: 9 In the mouth, the soft tissues of the gingiva, mucosa, tongue, and pharynx are examined for redness, swelling or deformity. Finally, the teeth are examined. Each tooth that may be painful is percussed (tapped), palpated at the base of the root, and probed with a dental explorer for dental caries and a periodontal probe for periodontitis, then wiggled for mobility.[10]^: 10

Sometimes the symptoms reported in the history are misleading and point the examiner to the wrong area of the mouth. For instance, sometimes people may mistake pain from pulpitis in a lower tooth as pain in the upper teeth, and vice versa. In other instances, the apparent examination findings may be misleading and lead to the wrong diagnosis and wrong treatment. Pus from a pericoronal abscess associated with a lower third molar may drain along the submucosal plane and discharge as a parulis over the roots of the teeth towards the front of the mouth (a "migratory abscess"). Another example is decay of the tooth root which is hidden from view below the gumline, giving the casual appearance of a sound tooth if careful periodontal examination is not carried out.

Factors indicating infection include movement of fluid in the tissues during palpation (fluctuance), swollen lymph nodes in the neck, and fever with an oral temperature more than 37.7 °C.

Any tooth that is identified, in either the history of pain or base clinical exam, as a source for toothache may undergo further testing for vitality of the dental pulp, infection, fractures, or periodontitis. These tests may include:[10]^: 10–19

• Pulp sensitivity tests, usually carried out with a cotton wool pledget sprayed with ethyl chloride to serve as a cold stimulus, or with an electric pulp tester. The air spray from a three-in-one syringe may also be used to demonstrate areas of dentin hypersensitivity. Heat tests can also be applied with hot Gutta-percha. A healthy tooth will feel the cold but the pain will be mild and disappear once the stimulus is removed. The accuracy of these tests has been reported as 86% for cold testing, 81% for electric pulp testing, and 71% for heat testing. Because of the lack of test sensitivity, a second symptom should be present or a positive test before making a diagnosis.
• Radiographs utilized to find dental caries and bone loss laterally or at the apex.
• Assessment of biting on individual teeth (which sometimes helps to localize the problem) or the separate cusps (may help to detect cracked cusp syndrome).

Less commonly used tests might include trans-illumination (to detect congestion of the maxillary sinus or to highlight a crack in a tooth), dyes (to help visualize a crack), a test cavity, selective anaesthesia and laser doppler flowmetry.

• 
  Pulp sensibility test using ethyl chloride (cold stimulus)
• 
  Electric pulp tester
• 
  Plastic wedge to identify pain on biting from a fractured tooth
• 
  Transillumination demonstrating fracture
• 
  Decay (green) with apical abscess (blue)
• 
  Gutta-percha point indicating abscess origin

Establishing a diagnosis of nondental toothache is initially done by careful questioning about the site, nature, aggravating and relieving factors, and referral of the pain, then ruling out any dental causes. There are no specific treatments for nondental pain (each treatment is directed at the cause of the pain, rather than the toothache itself), but a dentist can assist in offering potential sources of the pain and direct the patient to appropriate care. The most critical nondental source is the radiation of angina pectoris into the lower teeth and the potential need for urgent cardiac care.[10]^: 68

When it becomes extremely painful and decayed the tooth may be known as a hot tooth.[45]

In pulpitis, an important distinction in regard to treatment is whether the inflammation is reversible or irreversible. Treatment of reversible pulpitis is by removing or correcting the causative factor. Usually, the decay is removed, and a sedative dressing is used to encourage the pulp to return to a state of health,[10]^: 41 either as a base underneath a permanent filling or as a temporary filling intended to last for a period while the tooth is observed to see if pulpitis resolves. Irreversible pulpitis and its sequalae pulp necrosis and apical periodontitis require treatment with root canal therapy or tooth extraction, as the pulp acts as a nidus of infection, which will lead to a chronic infection if not removed. Generally, there is no difference in outcomes between whether the root canal treatment is completed in one or multiple appointments.[47] The field of regenerative endodontics is now developing ways to clean the pulp chamber and regenerate the soft and hard tissues to either regrow or simulate pulp structure. This has proved especially helpful in children where the tooth root has not yet finished developing and root canal treatments have lower success rates.[10]^{: 602–618}

Reversible/irreversible pulpitis is a distinct concept from whether the tooth is restorable or unrestorable, e.g. a tooth may only have reversible pulpitis, but has been structurally weakened by decay or trauma to the point that it is impossible to restore the tooth in the long term.

A general principle concerning dental abscesses is ubi pus, ibi evacua ("where there is pus, drain it"), which applies to any case where there is a collection of pus in the tissues (such as a periodontal abscess, pericoronal abscess, or apical abscess). The pus within the abscess is under pressure, and the surrounding tissues are deformed and stretched to accommodate the swelling. This leads to a sensation of throbbing (often in time with the pulse) and constant pain. Pus may be evacuated via the tooth by drilling into the pulp chamber (an endodontic access cavity). Such a treatment is sometimes termed open drainage. Drainage can also be performed via the tooth socket, once the causative tooth is extracted. If neither of those measures succeeds, or they are impossible, incision and drainage may be required, in which a small incision is made in the soft tissues directly over the abscess at the most dependent point. A surgical instrument such as a pair of tweezers is gently inserted into the incision and opened, while the abscess is massaged to encourage the pus to drain out. Usually, the reduction in pain when the pus drains is immediate and marked as the built up pressure is relieved. If the pus drains into the mouth, there is usually a bad or offensive taste.

Antibiotics tend to be extensively used for emergency dental problems.[48][49] As samples for microbiologic culture and sensitivity are hardly ever carried out in general dental practice, broad-spectrum antibiotics such as amoxicillin are typically used for a short course of about three to seven days.[48] Antibiotics are seen as a "quick fix" by both dentists, who generally only have a very short time to manage dental emergencies, and by patients, who tend to want to avoid treatments (such as tooth extraction) which are perceived negatively. However, antibiotics typically only temporarily suppress an infection, and the need for definitive treatment is only postponed for an unpredictable length of time. An estimated 10% of all antibiotic prescriptions are made by dentists, a major factor in antibiotic resistance.[48][49] They are often used inappropriately,[49] in conditions for which they are ineffective, or their risks outweigh the benefits, such as irreversible pulpitis,[50] apical abscess,[15]^: 303 dry socket,[15]^: 303 or mild pericoronitis.[15]^: 303 However, the reality is that antibiotics are rarely needed,[51]^: 230 and they should be used restrictively in dentistry.[52]^: 164 Local measures such as incision and drainage, and removal of the cause of the infection (such as a necrotic tooth pulp) have a greater therapeutic benefit and are much more important.[51]^: 230 If abscess drainage has been achieved, antibiotics are not usually necessary.[15]^: 303

Antibiotics tend to be used when local measures cannot be carried out immediately.[15]^: 303 In this role, antibiotics suppress the infection until local measures can be carried out. Severe trismus may occur in when the muscles of mastication are involved in an odontogenic infection, making any surgical treatment impossible. Immunocompromised individuals are less able to fight off infections, and antibiotics are usually given.[51]^: 232 Evidence of systemic involvement (such as a fever higher than 38.5 °C, cervical lymphadenopathy, or malaise) also indicates antibiotic therapy, as do rapidly spreading infections, cellulitis, or severe pericoronitis.[15]^: 303[51]^: 232 Drooling and difficulty swallowing are signs that the airway may be threatened, and may precede difficulty in breathing. Ludwig's angina and cavernous sinus thrombosis are rare but serious complications of odontogenic infections. Severe infections tend to be managed in hospital.