Dental abscesses

If a patient comes to you with a painful, throbbing, swollen, red face (a ''fat face'), perhaps with fever, trismus and lymphadenitis, he is probably suffering from an acute dental or oral infection, most probably an alveolar abscess. He may have:

(1) An alveolar abscess begins as an infection in the bone around a non-vital infected tooth. He has severe pain, which becomes less as pus is released into more superficial tissues and his face starts to swell. After 36 hours of cellulitis he usually has a fluctuant abscess which needs draining. If drainage is delayed, the pus in his abscess discharges spontaneously through a sinus (26-8) in his gum or face, which may become chronic.

First, control infection with antibiotics, and then drain the abscess, either by incising it where it is pointing, or by removing the infected tooth, which acts as a cork to prevent the pus escaping, or by doing both these things. If you remove a tooth before you have controlled the infection with antibiotics, and while his face is still severely swollen, you may spread the infection; your task will also be more difficult.

(2) A periodontal abscess at the side of a tooth, caused by spread from an infected gum.

(3) A pericoronal abscess caused by infection of the gum over the crown of an unerupted and impacted tooth, usually a lower third molar (''an infected wisdom tooth'). Often, an abscess does not form, and the gum round the tooth is merely inflamed.

Pus from all three of these foci of infection, and particularly from an alveolar abscess, can track in various directions, towards his cheek, his tongue, or his palate, or downwards into his neck. It can discharge inside his mouth or outside. It can collect: (1) On any of the surfaces of his gum (''gumboils'). (2) In the buccal sulcus of either jaw on the oral or deeper side of the attachment of his buccinator muscle (common). (3) On the surface of his face superficial to the buccinator attachment. (4) On his palate (less common). (5) In his submasseteric space between his masseter and the ascending ramus of his mandible. (6) In his pterygomandibular space between his medial pterygoid and the ascending ramus of his mandible. (7) In his sublingual space above or below his mylohyoid muscle. (8) In his submandibular space superficial to his mylohyoid. (9) In his submental space in the midline under his jaw. (10) Anywhere down the side of his neck. Don't be daunted by the complexity of this anatomy. Some of these spaces communicate with one another and more than one space may be involved[md]incise the abscess where it points, having due regard, where you can, for the skin lines on his face (61- 3).

Infection can spread in some particularly dangerous directions: (1) From his upper jaw (or upper lip or nose) to his cavernous sinus, which may thrombose, perhaps fatally (5.5). (2) From his lateral pharyngeal space up towards the base of his skull, down to his glottis or into his mediastinum. Infection of this space is one of the most dangerous conditions in dentistry. He has difficulty swallowing and speaking. (3) From his lower jaw, via his sublingual and submandibular spaces, to the tissues of his neck, where it may cause oedema of his glottis, respiratory obstruction and death. This is Ludwig's angina (5.10).

Fig. 5-7 THE DIRECTIONS IN WHICH PUS CAN SPREAD. A, and B, are views of the same structures at 90[de] to one another. The attachments of a patient's mylohyoid and buccinator muscles determine whether pus, orginating in his lower jaw, points inside or outside his mouth. A, shows pus from his lower third molar spreading into his buccal space, his submasseteric space, and his lateral pharyngeal space. B, shows the attachments of his mylolyoid and buccinator muscles. The attachments of these muscles determine whether pus spreads into his sublingual space, his submandibular space, his buccal sulcus, or on to the surface of his face. C, shows the incision of an abscess in his buccal sulcus. Partly after ''Hamilton Bailey's Emergency Surgery', edited by Dudley HAF, Fig. 151. John Wright, with kind permission. BEWARE OF CAVERNOUS SINUS THROMBOSIS AND LUDWIG'S ANGINA

DENTAL ABSCESSES For the general method, see Section 5.2.

HISTORY AND EXAMINATION. A patient of any age over 5 years walks into casualty with a fat face looking ill and distressed. He has usually had toothache in the past, but the pain has gone. Now he tells you that he has had pain for a week. He has fever, trismus, and a unilateral, tender, shiny, warm, indurated swelling. Looking at him will tell you which side of his face and which jaw is involved. Feel for warmth with the back of your index finger and test for fluctuation. A tooth with large holes in it probably has an apical abscess under it. It may be firm, but is usually loose. If he has obvious periodontal disease, or several loose teeth, suspect a periodontal abscess.

If you are in doubt as to which of his teeth is the site of infection, tap them with some metal object or press them with your gloved index finger. A tooth which is much more painful than the others is probably the source of an alveolar infection. It may also be slightly raised in its socket. A tooth with a periodontal abscess is much less tender to percussion.

X-RAYS. If possible, X-ray the offending tooth. You may see: (1) A a radiolucent area at its apex when an apical abscess has been present for 2 or 3 weeks. (2) Caries between two adjacent teeth which may not be visible from his mouth. (3) The impacted tooth which is responsible for a pericoronal abscess. (4) Some other source for the infection, such as an infected cyst, or a fracture.

THE DIFFERENTIAL DIAGNOSIS includes acute inflammation of the salivary glands (5.9), mumps, Burkitt's lymphoma (32.3), lymph node swellings and glandular fever.

GENERAL MEASURES. Admit him and make sure that his fluid intake is adequate; he may find drinking difficult.

CAUTION ! Don't apply poultices or any kind of local heat to his face[md]they may spread the infection. If an abscess is pointing inside his mouth, hot saline mouth washes may ease his pain.

ANTIBIOTICS are often unnecessary, because many dental infections can be treated by local drainage only. If there is spreading cellulitis he needs an antibiotic. Procaine penicillin 600,000 units (2 ml) intramuscularly is adequate in most cases. But if his condition is serious give him a megaunit of benzyl penicillin 4 to 6-hourly.

When you have drained an abscess, culture the pus and change the antibiotic if necessary.

CAUTION ! Make sure that he understands that a course of antibiotics is not sufficient treatment for his abscess, and that he must return, even if his swelling improves.

ANAESTHESIA. (1) 2% or 4% lignocaine spray or a swab soaked in lignocaine solution. (2) Inject a local anaesthetic solution into the outer wall of the abscess over the proposed site of the incision. (3) Ethyl chloride local spray is suitable for an abscess which presents on his face or in his labial or buccal sulci. Isolate the infected area with gauze packs, and then spray on ethyl chloride until crusting occurs. Then open the abscess with a No. 11 blade.

CAUTION! Avoid general anaesthesia, if you can, unless it is expert (especially if he is in danger of respiratory obstruction[md]see A 13.2), and you can intubate him and pack off his throat.

ALVEOLAR ABSCESSES If you can refer him, a dentist may be able to save his tooth by draining the abscess through it, and later filling its root. If you cannot refer him, remove it. Many abscessed teeth are loose, and you can easily pick them out of their sockets. Removing his tooth to allow pus to drain through the socket, combined with antibiotic treatment may be sufficient. Don't incise a non-fluctuant swelling. If it is not yet fluctuant and ripe for incision, ask him to use hot saline mouth washes, as hot as he can bear without the risk of being scalded, several times a day. Give him an antibiotic and wait. This may control his infection and arrest pus formation.

CAUTION ! (1) Don't pull out his tooth (26.3) before you have controlled his cellulitis. (2) If he has a tense inflammatory swelling of the upper part of his neck, suspect Ludwig's angina and treat him urgently (5.10).

PUS POINTING INSIDE HIS MOUTH can point in several places:

If an abscess is pointing on his alveolus, open it into his mouth.

If it is pointing in his labial sulcus (C, 5-7), make a 1.5 cm incision through his mucous membrane parallel to his alveolar ridge. Push a fine haemostat into it and open the jaws.

If it is pointing in his palate, make an anteroposterior incision, parallel to its nerves and vessels, remove an ellipse of tissue and let the pus flow out.

If he has pus in his pterygomandibular, lateral pharyngeal, or submasseteric spaces, drain it through a vertical incision inside his mouth parallel to the ascending ramus of his mandible, taking care to avoid his parotid duct (61-5). This runs in his cheek under the middle third of a line between the tragus of his ear and the commissure of his lips, and opens in line with his first molar tooth. Push forceps to the lingual or buccal side of his ramus, wherever the pus seems to be pointing. If it is under his masseter, insert a drain deep to this muscle down to his mandible from outside his face. Insert the drain through an incision just below the inferior border of his mandible.

PUS POINTING OUTSIDE HIS MOUTH. Drain it through one of the incisions below, as soon as any cellulitis he may have has stopped spreading. Removing his tooth to let the pus drain is not enough, even if it does drip from his root canal. If his abscess is fluctuant, it needs draining too. If you are not sure if it is ready for drainage or not, insert a wide bore needle under local anaesthesia. If you aspirate pus, incise it by Hilton's method (5.2) where it points at the softest and most tender spot. To minimize scarring, make an incision below the inferior border of his mandible, where possible. If you have to make it on his face, make it in line with the creases in his skin (61-3). These may not always be over the most fluctuant part of the abscess.

CAUTION ! When you plan your incision, consult Figures 5-7a and 61-3 and remember: (1) The extension of the lower pole of his parotid gland into the side of his neck (61-5). (2) The mandibular branches of his facial nerve. These run horizontally and cross the lower border of his mandible, just anterior to his masseter, deep to his platysma muscle in his anterior mandibular region and deep to the fascia posteriorly. (3) His facial artery and vein. These enter his face from between his submandibular salivary gland and the lower border of his mandible; they cross the ramus of his mandible 3 cm from the angle of his jaw and then run obliquely across the lower third of his face superficially on his buccinator muscle. You may have to compromise between chosing the best site for dependent drainage and an inconspicuous scar in the crease lines of his face. Here are some likely sites:

If he has a submental abscess, drain it through a small midline transverse incision under his chin.

If the abscess is under the body of his mandible, drain it through a horizontal incision 1 to 2 cm below the lower border of his mandible, taking care to avoid the mandibular branch of his facial nerve and his facial vessels. Push sinus forceps towards the lingual side of his mandible to drain the pus there.

If the abscess points external to his buccinator, drain it through a small incision over the swelling.

DRAINS. Stitch a corrugated or tubular rubber or plastic drain into the wound for 2 to 5 days, or leave it open with its edges separated by gauze.

PERIODONTAL ABSCESS. If you cannot refer him for a conservative operation, pull out his tooth (26.3).

PERICORONAL INFECTION (infected ''wisdom tooth'). See Section 26.4.

POSTOPERATIVELY, after you have incised any intraoral abscess, give him hot mouth washes to help the incision stay open as long as is necessary.

DIFFICULTIES. [f41]If he CANNOT OPEN HIS MOUTH to let you get at the abscess, he probably still has cellulitis, and his abscess is not yet fit for incision. So continue antibiotics and try again later.

Fig. 5-7a DRAINING A PAROTID ABSCESS. A, the anatomy of the parotid gland. A patient's facial nerve enters the substance of his parotid so that, if you only incise his skin and subcutaneous tissue superficial to the gland when you reflect the flap, you will not injure it. Note that it extends well down into his neck. Incise where his pinna meets the skin of his face and neck and continue on in a skin crease. B, turn back the flap and incise radially to avoid the branches of his facial nerve.

1, the parotid gland. 2, the parotid duct. 3, the border of the mandible. 4, the facial artery crossing the mandible about 3 cm anterior to its angle. 5, the facial vein. 6, the incision. 7, the facial nerve.