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Ultrasound versus OPG in the diagnosis of a dental abscess in patients presenting to the A&E department.

Three Part Question

In [patients presenting to the A&E department with a queried dental abscess] is [ultrasound or OPG better] in terms of [making the correct diagnosis].

Clinical Scenario

A 24 year old man presents to the A&E minors department referred by the dental emergency unit. He is complaining of a dull and constant pain localised to the lower right 4th, 5th and 6th. Although he is systemically well you can feel a submandibular swelling just below the affected teeth.

Search Strategy

Pubmed search
[dental abscess] AND [ultrasound OR ultrasonography] AND [OPG OR Orthopantomogram OR panorex]

Search Outcome

338 papers
1 Relevant Paper

Relevant Paper(s)

Author, date and country Patient group Study type (level of evidence) Outcomes Key results Study Weaknesses
Adhikari et al
19 patients who had both bedside US and OPG.Retrospective reviewResolution of symptoms with antibiotics. US & OPG agree in 86% of cases. In the one case where they did not, US was correct in detecting abscess and proven by incision and drainage.Small sample group. Ultrasound is operator dependant.
Incision & drainage to confirm (1 case)


While this small sample group has yielded good results, a larger patient sample is needed. The operator-dependent nature of ultrasound must also be considered. In addition OPG may help to pick up various other disorders that ultrasound cannot such as TMJ dysfunction, fractures and malocclusions which may not present so distinctly as to separate them from dental abscess.

Clinical Bottom Line

Ultrasound is useful to confirm if dental abscess is suspected, may even yield better results than OPG and there is no radiation exposure- but it is operator dependent and requires a certain level of training expertise.

Level of Evidence

Level 2 - Studies considered were neither 1 or 3.


  1. Adhikari S, Blaivas M, Lander L Comparison of bedside ultrasound and panorex radiography in the diagnosis of a dental abscess in the ED Am J Emerg Med April 30, 2010