26. Periodontal alterations. Clinical root and clinical crown. Alterations related to partial edentulism.
Explains how the clinical crown and clinical root are defined and how their proportions shift with eruption, recession and bone loss, with a crown-to-root ratio table showing what each proportion means for an abutment. Goes on to periodontal changes from ageing and disease, then the chain-like effects of partial tooth loss, including tipping, over-eruption, open contacts and the Godon phenomenon, with a figure and a table of changes.
Topic 26 of 75 in the MU Sofia syllabus for Preclinics of Dental Prosthetics (Dental Medicine, Year 2). The free AceMed note covers it in 4 sections, about 258 words (3 min of reading), with 13 flashcards.
In this note
Introduction
Clinical crown and clinical root
Periodontal changes with age and disease
Changes after partial tooth loss
Introduction
The periodontium changes with age, with disease and when neighbouring teeth are lost. Each change shifts how much load a tooth can carry and whether it can still serve as an abutment.
Clinical crown and clinical root
Clinical crown: the part of the tooth above the gingival margin.
Clinical root: the part held in bone and soft tissue, not visible in the mouth.
Their proportions change through life. After eruption the clinical crown grows longer as the tooth emerges. Later, gingival recession and loss of alveolar bone lengthen it further and shorten the part of the root still anchored in bone.
Crown-to-root ratio
As bone is lost the fulcrum of the tooth moves toward the apex. The crown becomes a longer lever, the same biting force tips the tooth harder, and mobility grows.
Periodontal changes with age and disease
Gingival recession; exposed cementum, sensitive and prone to caries.
Loss of alveolar bone height; widening of the periodontal space under overload.
Increased tooth mobility and less root area to carry the load (see topic 22).
Trauma from occlusion: overload widens the ligament space and resorbs the bone, especially combined with inflammation.
Continue reading free
The whole note, all 4 sections, is free with an AceMed account, with its 13 flashcards. Premium adds flashcard recall, highlights and Ask AI.
