Acute inflammation in periapical tissues — ORE Part 1 MCQ

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HardApplied Dental SciencesAcute inflammation in periapical tissuesORE Part 1

A non-vital lower molar becomes acutely tender to bite. A periapical radiograph shows widening of the periodontal ligament space without a large periapical radiolucency. The patient reports that the tooth feels slightly raised in its socket. What is the most likely anatomical and physiological explanation?

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Correct answer: A — Oedema in the periodontal ligament increases pressure

Explanation lettering: B = shown as A · A = shown as B · D = shown as C · E = shown as D · C = shown as E

**B is correct.** Pulp necrosis and infection can produce symptomatic apical periodontitis: acute inflammation of the periapical soft tissues, including the periodontal ligament (PDL). Inflammatory oedema/exudate within this confined ligament space widens the PDL radiographically and slightly displaces the tooth occlusally, giving the sensation that it is “high.” Loading the tooth during biting or percussion mechanically stimulates the inflamed, sensitised PDL and causes pain. SDCEP describes this condition as acute inflammation around the root apex, with tenderness to pressure; occlusal relief may be appropriate. Enamel cannot inflame or expand (A). A necrotic pulp cannot become more proprioceptive (C); the relevant sensory response is periapical/PDL. Cementum does not acutely contract (D), and salivary ducts have no anatomical role in tooth elevation (E).

Reference: Scottish Dental Clinical Effectiveness Programme. Management of Acute Dental Problems: “Symptomatic apical periodontitis”, 2026. https://www.acutedentalproblems.sdcep.org.uk/guidance/management-of-oral-conditions/common-oral-conditions/symptomatic-apical-periodontitis/