Cementicle Explained

Cementicle
Field:	Dentistry

A cementicle is a small, spherical or ovoid calcified mass embedded within or attached to the cementum layer on the root surface of a tooth, or lying free within the periodontal ligament.^{[1] [2]} They tend to occur in elderly individuals.

There are 3 types:

• Free cementicle – not attached to cementum^[3]
• Attached (sessile) cementicle – attached to the cementum surface (also termed exocementosis)
• Embedded (interstitial) cementicle – with advancing age the cementum thickens,^[4] and the cementicle may become incorporated into the cementum layer

They may be visible on a radiograph (x-ray). They may appear singly or in groups, and are most commonly found at the tip of the root. Their size is variable, but generally they are small (about 0.2 mm^[5] – 0.3 mm in diameter).

Cementicles are usually acellular, and may contain either fibrillar or afibrillar cementum, or a mixture of both. Cementicles are the result of dystrophic calcification, but the reason why this takes place is unclear. Cementicles are thought to form when calcification occurs around a nidus, a precipitating center. Around this nidus they slowly enlarge by further deposition of calcium salts. Examples of how cementicles are thought to form include:

• Calcification due to degenerative changes in the epithelial cell rests of Malassez
• Calcification of thrombosed (blocked) capillaries in the periodontal ligament (i.e. a phlebolith)
• Microtrauma to Sharpey's fibres causes small spicules of cementum or alveolar bone to splinter into the periodontal membrane^[6] Some do not consider these as true cementicles.

Notes and References

1. Book: Chiego Jr. DJ. Essentials of Oral Histology and Embryology: A Clinical Approach. 14 April 2014. Elsevier Health Sciences. 978-0-323-29100-2. 133.
2. Book: Bath-Balogh M. Fehrenbach MJ. Illustrated Dental Embryology, Histology, and Anatomy. 10 December 2010. Elsevier Health Sciences. 978-1-4377-2934-4. 174.
3. Book: Ghom A. Mhaske S. Textbook of Oral Pathology. 17 September 2010. Jaypee Brothers Publishers. 978-81-8448-402-1. 122.
4. Book: Kumar GS. Orban's Oral Histology & Embryology. 10 February 2014. Elsevier Health Sciences APAC. 978-81-312-3801-1. 196.
5. Book: Chatterjee K. Essentials of Oral Histology. 1 December 2006. Jaypee Brothers Publishers. 978-81-8061-865-9. 112.
6. Book: Mosby. Mosby's Dental Dictionary. 1 August 2013. Elsevier Health Sciences. 978-0-323-10013-7. 115.