Cementicle

Cementicle
Specialty	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 senior population. ^{[3] [4]}

There are 3 types: ^{[5] [6]}

• Free cementicle – not attached to cementum ^[5]
• Attached (sessile) cementicle – attached to the cementum surface ^[5] (also termed exocementosis) ^[3]
• Embedded (interstitial) cementicle – with advancing age the cementum thickens, ^[3] and the cementicle may become incorporated into the cementum layer ^[5]

They may be visible on a radiograph (x-ray). ^[2] They may appear singly or in groups, ^[1] and are most commonly found at the tip of the root. ^[6] Their size is variable, ^[5] but generally they are small (about 0.2 mm ^[6] – 0.3 mm in diameter). ^[5]

Cementicles are usually acellular, and may contain either fibrillar or afibrillar cementum, or a mixture of both. ^[5] Cementicles are the result of dystrophic calcification, ^[5] but the reason why this takes place is unclear. ^[3] 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. ^[5] Examples of how cementicles are thought to form include:

• Calcification due to degenerative changes in the epithelial cell rests of Malassez ^[5]
• Calcification of thrombosed (blocked) capillaries in the periodontal ligament ^[5] (i.e. a phlebolith) ^[6]
• Microtrauma to Sharpey's fibres ^[2] causes small spicules of cementum or alveolar bone to splinter into the periodontal membrane ^[4] Some do not consider these as true cementicles. ^[5]

References

1. Chiego Jr. DJ (14 April 2014). Essentials of Oral Histology and Embryology: A Clinical Approach. Elsevier Health Sciences. p. 133. ISBN   978-0-323-29100-2.
2. Fehrenbach MJ; Popowics T. Illustrated Dental Embryology, Histology, and Anatomy (2026 ed.). Elsevier. p. 196. ISBN   9780443104244.
3. Kumar GS (10 February 2014). Orban's Oral Histology & Embryology. Elsevier Health Sciences APAC. p. 196. ISBN   978-81-312-3801-1.
4. Mosby (1 August 2013). Mosby's Dental Dictionary. Elsevier Health Sciences. p. 115. ISBN   978-0-323-10013-7.
5. Ghom A; Mhaske S (17 September 2010). Textbook of Oral Pathology. Jaypee Brothers Publishers. p. 122. ISBN   978-81-8448-402-1.
6. Chatterjee K (1 December 2006). Essentials of Oral Histology. Jaypee Brothers Publishers. p. 112. ISBN   978-81-8061-865-9.