Lamina Dura

The lamina dura is a thin, dense layer of cortical bone that lines the tooth socket (alveolus) immediately surrounding the root. On dental radiographs it typically appears as a continuous radiopaque (white) line and corresponds to the surface of the alveolar bone where the periodontal ligament fibres attach.

Clinically, the appearance of the lamina dura is an important radiographic sign: a well-defined lamina dura often reflects healthy bone and ligament support, whereas thinning, disruption or absence of the lamina dura can be associated with periodontal disease, periapical infection, trauma or resorption. Dentists interpret changes in the lamina dura together with symptoms and clinical examination, because radiographic appearance alone does not always identify the underlying cause.