Editing Toothache (section)

==Causes==
Toothache may be caused by ''dental'' (''odontogenic'') conditions (such as those involving the dentin-pulp complex or [[periodontium]]), or by ''non-dental'' (''non-odontogenic'') conditions (such as [[sinusitis|maxillary sinusitis]] or [[angina pectoris]]). There are many possible non-dental causes, but the vast majority of toothache is dental in origin.<ref name=Hargreaves2011>{{cite book|vauthors=Hargreaves KM, Cohen S, Berman LH |title=Cohen's pathways of the pulp|year=2011|publisher=Mosby Elsevier|location=St. Louis, Mo.|isbn=978-0-323-06489-7|url=https://books.google.com/books?id=JI7gSo5zcWEC|edition=10th}}</ref>{{rp}}

Both the pulp and periodontal ligament have [[nociceptor]]s (pain receptors),<ref name=Shephard2014>{{cite journal|vauthors=Shephard MK, MacGregor EA, Zakrzewska JM |title=Orofacial Pain: A Guide for the Headache Physician|journal=Headache: The Journal of Head and Face Pain|date=January 2014|volume=54|issue=1|pages=22–39|doi=10.1111/head.12272|pmid=24261452|s2cid=44571343}}</ref> but the pulp lacks [[proprioceptor]]s (motion or position receptors) and [[mechanoreceptor]]s (mechanical pressure receptors).<ref name=Scully2013 />{{rp|125–135}}<ref name=Cawson2008 /> Consequently, pain originating from the dentin-pulp complex tends to be poorly localized,<ref name="Cawson2008">{{Cite book | isbn = 978-0702040016 | title = Cawson's essentials of oral pathology and oral medicine | last1 = Cawson | first1 = RA | year = 2008 | publisher = Churchill Livingstone | location = Edinburgh | page = 70  }}</ref> whereas pain from the periodontal ligament will typically be well localized,<ref name=Hargreaves2011 />{{rp|55}} although not always.<ref name=Scully2013 />{{rp|125–135}}

For instance, the periodontal ligament can detect the pressure exerted when biting on something smaller than a grain of sand (10–30&nbsp;μm).<ref name=Lindhe2008>{{cite book|title=Clinical periodontology and implant dentistry|year=2008|publisher=Blackwell Munksgaard|location=Oxford|isbn=9781444313048|vauthors=Lindhe J, Lang NP, Karring T |edition=5th}}</ref>{{rp|48}} When a tooth is intentionally stimulated, about 33% of people can correctly identify the tooth, and about 20% cannot narrow the stimulus location down to a group of three teeth.<ref name=Hargreaves2011 />{{rp|31}} Another typical difference between pulpal and periodontal pain is that the latter is not usually made worse by thermal stimuli.<ref name=Scully2013 />{{rp|125–135}}

===Dental===
[[File:Pulpitis-gif.gif|thumb|right|[[Natural history of disease|Natural history]] of dental caries and resultant toothache and odontogenic infection.]]

====Pulpal====
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====
[[Pulpitis]] (inflammation of the pulp) can be triggered by various stimuli (insults), including mechanical, thermal, chemical, and bacterial irritants, or rarely [[Aerodontalgia|barometric changes]] and [[ionizing radiation]].<ref name=Neville2001>{{cite book|vauthors=Neville BW, Damm DD, Allen CA, Bouquot JE |title=Oral & maxillofacial pathology|year=2002|publisher=W.B. Saunders|location=Philadelphia|isbn=978-0-7216-9003-2|edition=2nd}}</ref>{{rp}} 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.<ref name=Hargreaves2011 />{{rp|36–37}}

Reversible pulpitis is characterized by short-lasting pain triggered by cold and sometimes heat.<ref name=Cawson2008 /> 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.<ref name="Hupp 2008">{{cite book|vauthors=Hupp JR, Ellis E, Tucker MR |title=Contemporary oral and maxillofacial surgery|year=2008|publisher=Mosby Elsevier|location=St. Louis, Mo.|isbn=978-0-323-04903-0|edition=5th}}</ref>{{rp|619–627}}

====Dentin hypersensitivity====
[[Dentin hypersensitivity]] is a sharp, short-lasting dental pain occurring in about 15% of the population,<ref name=Poulsen2006>{{cite journal|vauthors=Poulsen S, Errboe M, Lescay Mevil Y, Glenny AM |title=Potassium containing toothpastes for dentine hypersensitivity.|journal=The Cochrane Database of Systematic Reviews|date=July 19, 2006|volume=2006 |issue=3|pages=CD001476|pmid=16855970|doi=10.1002/14651858.CD001476.pub2|pmc=7028007}}</ref> which is triggered by cold (such as liquids
or air), sweet or spicy foods, and beverages.<ref>{{cite journal|title=Dentin hypersensitivity: Recent trends in management.|journal=[[Journal of Conservative Dentistry]]|date=October 2010|volume=13|issue=4|pages=218–24|pmid=21217949|vauthors=Miglani S, Aggarwal V, Ahuja B |pmc=3010026|doi=10.4103/0972-0707.73385 |doi-access=free }}</ref><!--I don't think the parallelism in this list makes sense anymore -- can all beverages of any type cause toothache? unlikely. Needs to be reworked so that list makes sense--> Teeth will normally have some sensation to these triggers,<ref name=Napenas2013 /> 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 [[Acid erosion|erosion]].<ref name=Petersson2013>{{cite journal|title=The role of fluoride in the preventive management of dentin hypersensitivity and root caries.|journal=Clinical Oral Investigations|date=March 2013|volume=17|pages=S63–71|doi=10.1007/s00784-012-0916-9|pmid=23271217|author=Petersson LG|issue=Suppl 1 |pmc=3586140}}</ref> The pulp of the tooth remains normal and healthy in dentin hypersensitivity.<ref name="Hargreaves2011" />{{rp|510}}

Many topical treatments for dentin hypersensitivity are available, including desensitizing toothpastes and protective varnishes that coat the exposed dentin surface.<ref name=Poulsen2006 /> Treatment of the [[root cause analysis|root cause]] is critical, as topical measures are typically short lasting.<ref name=Hargreaves2011 />{{rp|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.<ref name=Hargreaves2011 />{{rp|510}}

====Periodontal====
In general, chronic periodontal conditions do not cause any pain.  Rather, it is acute inflammation which is responsible for the pain.<ref name=Napenas2013>{{cite journal|author=Napeñas JJ|title=Intraoral pain disorders.|journal=Dental Clinics of North America|date=July 2013|volume=57|issue=3|pages=429–47|pmid=23809302|doi=10.1016/j.cden.2013.04.004}}</ref>

=====Apical periodontitis=====
[[File:Abscessed tooth periapical radiograph.jpg|thumb|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.<ref name=Segura-Egea2012>{{cite journal|vauthors=Segura-Egea JJ, Castellanos-Cosano L, Machuca G, Lopez-Lopez J, Martin-Gonzalez J, Velasco-Ortega E, Sanchez-Dominguez B, Lopez-Frias FJ |title=Diabetes mellitus, periapical inflammation and endodontic treatment outcome|journal=Medicina Oral Patología Oral y Cirugia Bucal|date=January 1, 2012|pages=e356–e361|doi=10.4317/medoral.17452|pmc=3448330|pmid=22143698|volume=17|issue=2}}</ref> 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 [[Sterilization (microbiology)|sterile]], non-infectious processes (such as trauma) may not cause any apical periodontitis.<ref name=Hargreaves2011 />{{rp|225}} Bacterial [[cytotoxin]]s 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.<ref name=Hargreaves2011 />{{rp|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 [[Radiodensity|radiolucent]] area around the end of the root, although this does not manifest immediately.<ref name=Hargreaves2011 />{{rp|228}} Acute apical periodontitis is characterized by well-localized, spontaneous, persistent, moderate to severe pain.<ref name=Scully2013 />{{rp|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.<ref name=Scully2013 />{{rp|125–135}}

=====Food impaction=====
[[Image:Open contact.jpg|thumb|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.<ref name=Scully2013 />{{rp|125–135}} The usual cause of food impaction is disruption of the normal [[embrasure (dentistry)|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,<ref group="nb">This pattern of pain should be distinguished from the "meal time syndrome" of certain [[salivary gland disease]]s.</ref> or relieved immediately by using a tooth pick or dental floss in the involved area.<ref name=Scully2013 />{{rp|125–135}} A gingival or periodontal abscess may develop from this situation.<ref name="Carranza11th"/>{{rp|444–445}}

=====Periodontal abscess=====
[[File:Cracked tooth lateral periodontal abscess.jpg|thumb|right|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 sulcus|gingival crevice]]s, 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 (dental)|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.<ref name="Carranza11th"/>{{rp|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.<ref name="Carranza11th"/>{{rp|444–445}} Toothache caused by a periodontal abscess is generally deep and throbbing. The [[oral mucosa]] covering an early periodontal abscess appears [[erythema]]tous (red), [[Swelling (medical)|swollen]], shiny, and [[hyperalgesia|painful to touch]].<ref name="AAP2000">{{cite journal | title=Parameter on acute periodontal diseases. | author=American Academy of Periodontology | journal=J Periodontol |date=May 2000 | volume=71 | issue=5 | pages=863–6 | pmid=10875694 | doi=10.1902/jop.2000.71.5-S.863| doi-access=free }}</ref>

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.<ref name="Carranza11th"/>{{rp|446–447}} The treatment of a periodontal abscess is similar to the management of dental abscesses in general (see: [[Toothache#Treatment|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]].<ref name="herrera2002">{{cite journal|title=A systematic review on the effect of systemic antimicrobials as an adjunct to scaling and root planing in periodontitis patients.|journal=Journal of Clinical Periodontology|year=2002|volume=29|pages=136–59; discussion 160–2|pmid=12787214|vauthors=Herrera D, Sanz M, Jepsen S, Needleman I, Roldán S |issue=Suppl 3 |doi=10.1034/j.1600-051X.29.s3.8.x}}</ref> 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 [[Dental plaque|plaque]] and calculus.

=====Acute necrotizing ulcerative gingivitis=====
[[File:Ulcerative necrotizing gingivitis.jpg|thumb|right|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 [[dental papilla|interdental papillae]], and possibly also [[halitosis]] (bad breath) and a bad taste. Predisposing factors include poor [[oral hygiene]], smoking, malnutrition, psychological stress, and immunosuppression.<ref name="Carranza11th"/>{{rp|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).<ref name=Lindhe2008_2>{{cite book| last1=Lindhe | first1=Jan | last2=Lang | first2=Niklaus P. | last3=Karring | first3=Thorkild|title=Clinical periodontology and implant dentistry|year=2008|publisher=Blackwell Munksgaard|location=Oxford|isbn=978-1-4051-6099-5|pages=413, 459|edition=5th}}</ref> 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.<ref name="Carranza11th">{{cite book | title=Carranza's clinical periodontology 11th edition | publisher=Elsevier Saunders | author=Newman, MG | year=2012 | location=St. Louis, Missouri | isbn=978-1-4377-0416-7}}</ref>{{rp|437–438}}

=====Pericoronitis=====
{{multiple image
| align     = right
| direction = vertical
| header    = Clinical & xray correlation of pericoronitis
| width     = 175
| image1    = 38 pericoronitis with pus.jpg
| alt1      = clinical shot of pericoronitis
| caption1  = An operculum (green arrow) over a partially erupted lower left third molar tooth. There is minimal inflammation and recurrent swelling.
| image2    = 38 pericornitis xray.jpg
| alt2      = xray of pericoronitis
| caption2  = 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.<ref name=Douglass2003>{{cite journal|last=Douglass|first=AB|author2=Douglass, JM |title=Common dental emergencies.|journal=American Family Physician|date=February 1, 2003|volume=67|issue=3|pages=511–6|pmid=12588073}}</ref> 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,<ref name="Carranza11th"/><ref name="Fragiskos 2007" />{{rp|122}} redness, swelling and tenderness of the gum over the tooth.<ref name="Wray 2003">{{cite book|vauthors=Wray D, Stenhouse D, Lee D, Clark AJ |title=Textbook of general and oral surgery|year=2003|publisher=Churchill Livingstone|location=Edinburgh [etc.]|isbn=978-0-443-07083-9}}</ref>{{rp|220–222}} There may be [[trismus]] (difficulty opening the mouth),<ref name="Wray 2003" />{{rp|220–222}} facial swelling, and [[rubor]] (flushing) of the cheek that overlies the angle of the jaw.<ref name="Carranza11th"/><ref name="Fragiskos 2007">{{cite book|author=Fragiskos FD|title=Oral surgery|year=2007|publisher=Springer|location=Berlin|isbn=978-3-540-25184-2|url=https://books.google.com/books?id=wJHV_TqpL_sC&q=9783540251842}}</ref>{{rp|122}} Persons typically develop pericoronitis in their late teens and early 20s,<ref name=Zakrzewska2009 />{{rp|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.<ref name="Carranza11th"/>{{rp|440–441}}

=====Occlusal trauma=====
[[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 habit|parafunctional]] (abnormal) clenching and grinding of teeth during sleep or while awake. Over time, there may be [[attrition (dental)|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]].<ref name="Carranza11th"/>{{rp|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.<ref name="Carranza11th"/>{{rp|153,753}} Over-tightening of [[Dental braces|braces]] can cause periodontal pain and, occasionally, a periodontal abscess.<ref name="Carranza11th"/>{{rp|503}}

=====Alveolar osteitis=====
[[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.<ref name=":0">{{Cite journal |last1=Daly |first1=Blánaid Jm |last2=Sharif |first2=Mohammad O. |last3=Jones |first3=Kate |last4=Worthington |first4=Helen V. |last5=Beattie |first5=Anna |date=2022-09-26 |title=Local interventions for the management of alveolar osteitis (dry socket) |journal=The Cochrane Database of Systematic Reviews |volume=2022 |issue=9 |pages=CD006968 |doi=10.1002/14651858.CD006968.pub3 |issn=1469-493X |pmc=9511819 |pmid=36156769}}</ref> 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.<ref name=Neville2001 /><ref name="Fragiskos 2007" />{{rp|122}}<ref name="Wray 2003" />{{rp|216–217}}<ref name=":0" /> Healing is delayed, and it is treated with local anesthetic dressings, which are typically required for five to seven days.<ref name="Wray 2003" />{{rp|216–217}} There is some evidence that [[chlorhexidine]] mouthwash used prior to extractions prevents alveolar osteitis.<ref name=":0" />

====Combined pulpal-periodontal====
=====Dental trauma and cracked tooth syndrome=====
[[File:Cracked tooth.png|thumb|right|Crown-root fracture with pulp involvement (left). Extracted (right).]]
[[Cracked tooth syndrome]] refers to a highly variable<ref name=Mathew2012>{{cite journal|vauthors=Mathew S, Thangavel B, Mathew CA, Kailasam S, Kumaravadivel K, Das A |title=Diagnosis of cracked tooth syndrome.|journal=Journal of Pharmacy & Bioallied Sciences|date=August 2012|volume=4|issue=Suppl 2|pages=S242–4|pmid=23066261|doi=10.4103/0975-7406.100219|pmc=3467890 |doi-access=free }}</ref> 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,<ref name=Banerji2010>{{cite journal|vauthors=Banerji S, Mehta SB, Millar BJ |title=Cracked tooth syndrome. Part 1: aetiology and diagnosis.|journal=British Dental Journal|date=May 22, 2010|volume=208|issue=10|pages=459–63|pmid=20489766|doi=10.1038/sj.bdj.2010.449|doi-access=free}}</ref> or relieved by releasing pressure on the tooth.<ref name=Hargreaves2011 />{{rp|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.<ref name=Hargreaves2011 />{{rp|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.<ref name=Hargreaves2011 />{{rp|27–31}} Vertical fractures can be very difficult to identify because the crack can rarely be probed<ref name=Hargreaves2011 />{{rp|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).<ref name=Hargreaves2011 />{{rp|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.<ref name="AAETrauma">{{cite web | url=http://www.nxtbook.com/nxtbooks/aae/traumaguidelines/ | title=The recommended guidelines of the American Association of Endodontists for the treatment of traumatic dental injuries | publisher=American Association of Endodontists | date=September 2013 | access-date=January 17, 2014 | pages=1–15 | archive-date=January 8, 2014 | archive-url=https://web.archive.org/web/20140108050117/http://www.nxtbook.com/nxtbooks/aae/traumaguidelines/ | url-status=dead }}</ref><ref name="traumaguide">{{cite web | url=http://dentaltraumaguide.org | title=Dental Trauma Guide | publisher=Rigshospitalet Region Hospital, Denmark, University of Copenhagen and the International Association of Dental Traumatology | access-date=January 15, 2014}}</ref>

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 [[Dental composite|composite resin]].  Should the fracture extend though the pulp chamber and into the root, the prognosis of the tooth is hopeless.<ref name=Hargreaves2011/>{{rp|25}}

=====Periodontic-endodontic lesion=====
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 [[Combined periodontic-endodontic lesions|periodontic-endodontic lesion]]s, 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.<ref>{{cite journal|last=Singh|first=P|title=Endo-perio dilemma: a brief review.|journal=Dental Research Journal|date=Winter 2011|volume=8|issue=1|pages=39–47|pmid=22132014|pmc=3177380}}</ref> Successful root canal therapy is required before periodontal treatment is attempted.<ref name="Carranza11th"/>{{rp|49}} Generally, the long-term prognosis of perio-endo lesions is poor.

===Non-dental===
[[File:Angina pectoris.png|thumb|right|Discomfort caused by coronary artery disease can radiate to the neck, lower jaw and teeth]]
{{See also|Orofacial pain}}
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 [[referred pain|refer pain]] to the teeth.<ref name=Sharav2008 />{{rp|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 pain|psychogenic]] in origin.<ref name=Hargreaves2011 />{{rp|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,<ref name=Renton2012 /> and [[neoplasm]]s of the sinus (such as [[adenoid cystic carcinoma]])<ref name=Barnes2009 />{{rp|390}} can cause similarly perceived toothache if malignant invasion of the superior alveolar nerves occurs.<ref name=Regezi2011>{{cite book|vauthors=Regezi JA, Sciubba JJ, Jordan RK |title=Oral pathology : clinical pathologic correlations|year=2011|publisher=Elsevier/Saunders|location=St. Louis, Mo.|isbn=978-1-4557-0262-6|edition=6th}}</ref>{{rp|72}} Classically, sinusitis pain increases upon [[Valsalva maneuver]]s or tilting the head forward.<ref name=Ferguson2014>{{cite journal|last1=Ferguson|first1=M|title=Rhinosinusitis in oral medicine and dentistry.|journal=Australian Dental Journal|date=May 23, 2014|pmid=24861778|doi=10.1111/adj.12193|volume=59|issue=3|pages=289–295|doi-access=free}}</ref>

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]]),<ref name=Barnes2009>{{cite book|author=Barnes L|title=Surgical pathology of the head and neck|year=2009|publisher=Informa healthcare|location=New York|isbn=978-1-4200-9163-2|edition=3rd}}</ref>{{rp|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]],<ref name=Regezi2011 />{{rp|340}} [[Infarction|infarct]]s in the jaws caused by [[sickle cell disease]],<ref name=Scully2010>{{cite book|author=Scully C|title=Medical problems in dentistry|year=2010|publisher=Churchill Livingstone|location=Edinburgh|isbn=978-0-7020-3057-4|url=https://books.google.com/books?id=PHLvOVaB0AEC&q=medical+problems+in+dentistry|edition=6th}}</ref>{{rp|214}} and [[osteomyelitis of the jaws|osteomyelitis]].<ref name=Shafer2010>{{cite book|last=Rajendran R|title=Shafer's textbook of oral pathology.|year=2010|publisher=Reed Elsevier|location=[S.l.]|isbn=978-81-312-1570-8}}</ref>{{rp|497}} Various conditions of the trigeminal nerve can masquerade as toothache, including trigeminal [[zoster]] (maxillary or mandibular division),<ref name=Scully2010 />{{rp|487}} [[trigeminal neuralgia]],<ref name=Renton2012>{{cite journal|vauthors=Renton T, Durham J, Aggarwal VR |title=The classification and differential diagnosis of orofacial pain.|journal=Expert Review of Neurotherapeutics|date=May 2012|volume=12|issue=5|pages=569–76|pmid=22550985|doi=10.1586/ern.12.40|s2cid=32890328}}</ref> [[cluster headache]],<ref name=Renton2012 /> and trigeminal [[neuropathy|neuropathies]].<ref name=Renton2012 /> Very rarely, a [[brain tumor]] might cause toothache.<ref name=Sharav2008 />{{rp|80,81}} Another chronic facial pain syndrome which can mimic toothache is [[temporomandibular disorder]] (temporomandibular joint pain-dysfunction syndrome),<ref name=Renton2012 /> 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).<ref name=Renton2012 /> 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). {{citation needed|date=April 2014}}