A Painless Nodule on the Gingiva of a 14-Year-Old Girl

Answer: Periapical dental abscess

An acute periapical abscess is the most common form of dental abscess.1 It is caused by an infection of the root canal of the tooth (pulpitis).1 Risk factors include broken, decayed, or maloccluded teeth, and prior failed root canal therapy. These infections are caused almost exclusively by anaerobic bacteria.1 Chronic infection may lead to bone resorption around the root of the infected tooth and start draining into the surrounding areas, causing facial swelling. If untreated, acute periapical abscess can also lead to osteomyelitis and cellulitis.

The etiology is usually polymicrobial, and the common causative organisms predominantly belong to the following phyla: Bacteroidetes, Firmicutes, Spirochaetes, Synergistetes, Proteobacteria, Fusobacteria, and Actinobacteria.2 Of note, in localized juvenile periodontitis, Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans infection should be considered when choosing treatment.3

Differential diagnoses of periapical dental abscess include dental eruption cyst or hematoma, gingival overgrowth (either inflammatory or drug-induced by, for example, phenytoin, nifedipine, or cyclosporine), hemangiomas, fibromas, and pyogenic granulomas. A parulis (gumboil) can form in association with the abscess at the exit point of the draining fistulous tract. It appears as a soft, solitary papule located apical to the abscessed tooth.

The presentation of periapical abscess can be varied. Acutely, patients usually have significant tooth pain and swelling of the surrounding gingiva.2 Chronic infection is a more indolent form, with low-grade inflammation and partial drainage of infected material. Symptoms include mild dull aching pain. Periapical abscess is rarely asymptomatic, as in our patient’s case. Signs of systemic involvement such as fever may indicate infiltration of the infection into the maxillary or mandibular bones. A dental radiograph is not usually needed to make a diagnosis of an abscess, but it can reveal bone loss along the ends of the dental roots, indicating an infection or abscess. The variations in presentation most likely are due to the diversity of the microbiota causing the infections, host resistance factors, and regional anatomy.

Antibiotic therapy is not normally indicated unless the patient is in a high-risk category due to immunosuppression or cardiac abnormality.4 However, many dentists prefer to start antibiotics to prevent dissemination of infection. Antibiotic therapy is also indicated in patients showing systemic signs of infection.4 Our patient was treated with amoxicillin and, later, root canal therapy to clean and remove the infection. This led to the complete resolution of the dental abscess.

Penicillins are the first-line agents if antibiotic therapy is chosen. Clindamycin is the antibiotic of choice in penicillin-allergic patients.5 Metronidazole’s lack of activity against aerobes and weak activity against anaerobic cocci make it a poor choice in patients with dental abscesses.5

Performing a thorough dental examination is vital, even if the patient denies symptoms.

REFERENCES:

1. Jenkins WMM, Papapanou PN. Epidemiology of periodontal disease in children and adolescents. Periodontol 2000. 2001;26:16-32.
2. Siqueira JF, Rôças IN. Microbiology and treatment of acute apical abscesses. Clin Microbiol Rev. 2013;26(2):255-273.
3. Califano JV; Research, Science and Therapy Committee American Academy of Periodontology. Position paper: periodontal diseases of children and adolescents. J Periodontol. 2003;74(11):1696-1704.
4. Cope AL, Francis N, Wood F, Chestnutt IG. Systemic antibiotics for symptomatic apical periodontitis and acute apical abscess in adults. Cochrane Database Syst Rev. 2018;(9):CD010136. doi:10.1002/14651858.CD010136.pub3.
5. Brown LJ, Löe H. Prevalence, extent, severity and progression of periodontal disease. Periodontol 2000. 1993;2:57-71.