Dental (periapical) abscesses are an acute infection of the periapical tissue around the root of the tooth.
Dental caries result in damage to the tooth enamel, which allows bacteria access to the dental pulp. From here the infection spreads down the root canal and out of the apical foramen where abscess formation occurs 2,4.
Early dental abscesses, within the first ten days, may not have any radiographic features 3,4.
Plain radiograph / OPG and CT
- well-defined lucency at or distal to the root apex, usually <10 mm with or without surrounding (<22 mm) sclerosis 2-4
- the tooth or teeth involved often show signs of caries
- an empty socket may indicate recent extraction for infection
Treatment and prognosis
Some dental abscesses will spontaneously resolve but dental surgery and antibiotics are generally required 1,4. Most (~90%) will show some evidence of healing (bone filling the lucency) one-year post-treatment 4.
Dental abscesses can exert pressure on the root of the tooth, which contains the neurovascular bundle, and can lead to devitalisation of the tooth 5.
Complications range from contiguous or haematogenous spread of infection and include potentially fatal conditions 1-4:
- meningitis and cerebral abscess
- Ludwig angina
deep neck space infections
- second and third molar periapical abscesses preferentially spread into the masticator and submandibular spaces (most common, ~80%), as the roots of these teeth extend below the insertion of the mylohyoid muscle which separates the submandibular space from the sublingual space.
- periapical abscesses of the other teeth usually spread into the facial soft tissue or sublingual space as their roots extend above the insertion of the mylohyoid muscle 6,7
- infection of the maxillary molars can involve the masticator space, maxillary sinuses and palate. Infection involving the masticator space can extend intracranially through the foramen ovale along the course of the trigeminal nerve (V3 branch) 8.
- odontogenic sinusitis
Possible differential considerations include:
- 1. Primary Care: A Collaborative Practice, 4e. Mosby. ISBN:0323075010. Read it at Google Books - Find it at Amazon
- 2. Abrahams JJ. Dental CT imaging: a look at the jaw. Radiology. 2001;219 (2): 334-45. doi:10.1148/radiology.219.2.r01ma33334 - Pubmed citation
- 3. Oral Radiology: Principles and Interpretation, 7e. Mosby. ISBN:0323096336. Read it at Google Books - Find it at Amazon
- 4. Scheinfeld MH, Shifteh K, Avery LL et-al. Teeth: what radiologists should know. Radiographics. 2012;32 (7): 1927-44. Radiographics (full text) - doi:10.1148/rg.327125717 - Pubmed citation
- 5. Steinklein J, Nguyen V. Dental Anatomy and Pathology Encountered on Routine CT of the Head and Neck. AJR Am J Roentgenol. 2013;201 (6): W843-53. doi:10.2214/AJR.12.9616 - Pubmed citation
- 6. Chapman MN, Nadgir RN, Akman AS et-al. Periapical lucency around the tooth: radiologic evaluation and differential diagnosis. Radiographics. 2013;33 (1): E15-32. doi:10.1148/rg.331125172 - Pubmed citation
- 7. Rafael M. Loureiro, Erica A. Naves, Rafael F. Zanello, Daniel V. Sumi, Regina L. E. Gomes, Mauro M. Daniel. Dental Emergencies: A Practical Guide. (2019) RadioGraphics. 39 (6): 1782-1795. doi:10.1148/rg.2019190019 - Pubmed
- 8. Kamalian S, Avery L, Lev M, Schaefer P, Curtin H, Kamalian S. Nontraumatic Head and Neck Emergencies. (2019) RadioGraphics. 39 (6): 1808-1823. doi:10.1148/rg.2019190159 - Pubmed
Related Radiopaedia articles
Lucent lesions of the jaw