Increased Overjet — ORE Part 1 MCQ

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EasyOrthodonticsIncreased OverjetORE Part 1

A 9-year-old presents with a Class II Division 1 malocclusion with an overjet of 8 mm. What is the increased risk associated with this overjet in a child of this age?

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Correct answer: C — Increased risk of traumatic dental injury to the upper incisors

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

An 8 mm overjet in a 9-year-old is a significant risk factor for traumatic dental injury to the upper incisors. Prospective and meta-analytic evidence shows that children with an overjet >6 mm have approximately 3.4 times the relative risk of trauma; those with >5 mm in mixed dentition have 2.4 times the odds. The mechanism is mechanical—greater incisal projection exposes the anterior teeth to impact injury during falls and contact sports. Traumatic dental injuries affect approximately 1 in 5 of such cases attributable to large overjet. Temporomandibular joint dysfunction (B) is not associated with overjet magnitude. Root resorption (C) occurs during fixed appliance therapy, not from untreated overjet. Caries (D) and periodontal disease (E) depend on plaque control and diet, not overjet size. Early orthodontic reduction of overjet is a recognised preventative strategy, making this a core clinical concept for the ORE.

Reference: Schatz J-P, Ostini E, Hakeberg M, Kiliaridis S. Large overjet as a risk factor of traumatic dental injuries: a prospective longitudinal study. Prog Orthod. 2020;21(1):41. https://pubmed.ncbi.nlm.nih.gov/33164157/