Sharpey's Fibres — MFDS Part 1 MCQ

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ModeratePhysiologySharpey's FibresMFDS Part 1

Which periodontal fibre system forms the collagen bundles whose terminal portions are embedded in cementum and alveolar bone as Sharpey's fibres?

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Correct answer: B — Principal fibres of the periodontal ligament

The correct answer is B. Sharpey's fibres are the mineralised, embedded terminal portions of the principal collagen fibre bundles of the periodontal ligament. Their insertion into root cementum and alveolar bone anchors the tooth within its socket and permits functional loading to be transmitted to the supporting tissues. Oxytalan fibres are elastic-system microfibrils within the periodontal ligament but do not form its principal tooth-to-bone attachment bundles. Gingival elastic fibres and reticular fibres are not the fibres inserted at both attachment surfaces. Type IV collagen is characteristically associated with basement membranes rather than the principal periodontal ligament fibre bundles.

Reference: Hirashima S, Kanazawa T, Ohta K, Nakamura KI. Three-dimensional ultrastructural imaging and quantitative analysis of the periodontal ligament. Anatomical Science International. 2020;95(1):1-11. https://pubmed.ncbi.nlm.nih.gov/31506855/