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Toothache and Infection
Pain in and around the teeth is a common problem, particularly among patients with poor oral hygiene. Pain may be constant, felt after stimulation (eg, heat, cold, sweet food or drink, chewing, brushing), or both.
The most common causes of toothache (see Some Causes of Toothache) are
Toothache is usually caused by dental caries and its consequences.
Caries (see Caries) causes pain when the lesion extends through the enamel into dentin. Pain usually occurs after stimulation from cold, heat, sweet food or drink, or brushing; these stimuli cause fluid to move within dentinal tubules to induce a response in the pulp. As long as the discomfort does not persist after the stimulus is removed, the pulp is likely healthy enough to be maintained. This is referred to as normal dentinal sensitivity, reversible pulpalgia, or reversible pulpitis.
Pulpitis (see Pulpitis) is inflammation of the pulp, typically due to advancing caries, cumulative minor pulp damage resulting from previous large restorations, a defective restoration, or trauma. It may be reversible or irreversible. Pressure necrosis frequently results from pulpitis. Pain may be spontaneous or in response to stimulation, particularly heat or cold. In both cases, pain lingers for a minute or longer. Once the pulp becomes necrotic, pain ends briefly (hours to weeks). Subsequently, periapical inflammation (apical periodontitis) or an abscess develops.
Periapical abscess may follow untreated caries or pulpitis. The tooth is exquisitely sensitive to percussion (tapping with a metal dental probe or tongue blade) and chewing. The abscess may point intraorally and eventually drain or may become a cellulitis.
Tooth trauma can damage the pulp. The damage may manifest soon after the injury or up to decades later.
Pericoronitis is inflammation and infection of the tissue between the tooth and its overlying flap of gingiva (operculum). It usually occurs in an erupting wisdom tooth (almost always a lower one).
Rarely, sinusitis (see Sinusitis) results from untreated maxillary dental infection. More commonly, pain resulting from a sinus infection is perceived as originating in the unaffected teeth adjacent to the sinus, mistakenly creating the impression of a dental origin.
Rarely, cavernous sinus thrombosis (see Cavernous Sinus Thrombosis) or Ludwig angina (submandibular space infection—see Submandibular Space Infection) develops; these conditions are life threatening and require immediate intervention.
Some Causes of Toothache
History of present illness should identify the location and duration of the pain and whether it is constant or present only after stimulation. Specific triggering factors to review include heat, cold, sweet food or drink, chewing, and brushing. Any preceding trauma or dental work should be noted.
Review of systems should seek symptoms of complications, including face pain, swelling, or both (dental abscess, sinusitis); pain below the tongue and difficulty swallowing (submandibular space infection); pain with bending forward (sinusitis); and retro-orbital headache, fever, and vision symptoms (cavernous sinus thrombosis).
Past medical history should note previous dental problems and treatment.
Vital signs are reviewed for fever.
The examination focuses on the face and mouth. The face is inspected for swelling and is palpated for induration and tenderness.
The oral examination includes inspection for gum inflammation and caries and any localized swelling at the base of a tooth that may represent a pointing apical abscess. If no tooth is clearly involved, teeth in the area of pain are percussed for tenderness with a tongue depressor. Also, an ice cube can be applied briefly to each tooth, removing it immediately once pain is felt. In healthy teeth, the pain stops almost immediately. Pain lingering more than a few seconds indicates pulp damage (eg, irreversible pulpitis, necrosis). The floor of the mouth is palpated for induration and tenderness, suggesting a deep space infection.
Neurologic examination, concentrating on the cranial nerves, should be done in patients with fever, headache, or facial swelling.
Red flag finding of headache suggests sinusitis, particularly if multiple upper molar and premolar (back) teeth are painful. However, presence of vision symptoms or abnormalities of the pupils or of ocular motility suggests cavernous sinus thrombosis.
Fever is unusual with routine dental infection unless there is significant local extension. Bilateral tenderness of the floor of the mouth suggests Ludwig angina.
Difficulty opening the mouth (trismus) can occur with any lower molar infection but is common only with pericoronitis.
Isolated dental condition: Patients without red flag findings or facial swelling likely have an isolated dental condition, which, although uncomfortable, is not serious. Clinical findings, particularly the nature of the pain, help suggest a cause (see Some Causes of Toothache and see Table: Characteristics of Pain in Toothache). Because of its innervation, the pulp can perceive stimuli (eg, heat, cold, sweets) only as pain. An important distinction is whether there is continuous pain or pain only on stimulation and, if pain is only on stimulation, whether the pain lingers after the stimulus is removed.
Swelling at the base of a tooth, on the cheek, or both indicates infection, either cellulitis or abscess. A tender, fluctuant area at the base of a tooth suggests a pointing abscess.
Characteristics of Pain in Toothache
Analgesics (see Treatment of Pain) are given pending dental evaluation and definitive treatment. For severe dental pain, local nerve block injections with bupivacaine hydrochloride and epinephrine 1:200,000 may relieve pain for many hours until the patient receives definitive dental care. A patient who is seen frequently for emergencies but who never receives definitive dental treatment despite availability may be seeking opioids.
Antibiotics directed at oral flora are given for most disorders beyond irreversible pulpitis (eg, necrotic pulp, abscess, cellulitis). Patients with pericoronitis should also receive an antibiotic. However, antibiotics can be deferred if patients can be seen the same day by a dentist, who may be able to treat the infection by removing the source (eg, by extraction, pulpectomy, or curettage). When antibiotics are used, penicillin or amoxicillin is preferred, with clindamycin the alternative.
An abscess associated with well-developed (soft) fluctuance is typically drained through an incision with a #15 scalpel blade at the most dependent point of the swelling. A rubber drain, held by a suture, may be placed.
Pericoronitis or erupting 3rd molars are treated with chlorhexidine 0.12% rinses or hypertonic saltwater soaks (1 tbsp salt mixed in a glass of hot water—no hotter than the coffee or tea a patient normally drinks). The salt water is held in the mouth on the affected side until it cools and then is expectorated and immediately replaced with another mouthful. Three or 4 glasses of salt water a day may control inflammation and pain pending dental evaluation.
Teething pain in young children may be treated with weight-based doses of acetaminophen or ibuprofen. Topical treatments can include chewing hard crackers (eg, biscotti), applying 7.5% or 10% benzocaine gel qid (provided there is no family history of methemoglobinemia), and chewing on anything cold (eg, gel-containing teething rings).
The rare patient with cavernous sinus thrombosis or Ludwig angina requires immediate hospitalization, removal of the infected tooth, and culture-guided parenteral antibiotics.
Most toothache involves dental caries or its complications (eg, pulpitis, abscess).
Symptomatic treatment and dental referral are usually adequate.
Antibiotics are given if signs of an abscess, necrotic pulp, or more severe conditions are present.
Very rare but serious complications include extension of dental infection to the floor of the mouth or to the cavernous sinus.
Dental infections rarely cause sinusitis, but sinus infection may cause pain perceived as originating in the teeth.
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