Dental Cementum Annulations
Definition
Annual bands in the dental cementum (analogous to tree rings) that can be counted microscopically from a thin tooth section to estimate age in years; reported accuracy of plus or minus 2-5 years in optimal conditions, but variable in replication studies.
- Also known as
- Tooth cementum annulation (TCA)
- Basis
- Annual growth bands in root cementum
- Reported accuracy
- About ±2 to 5 years in optimal conditions
- Method
- Thin-section microscopy of a tooth root
- Reliability
- Variable across replication studies
Common questions
Why is this method not treated as a standalone age estimate?+
Counting the bands is technically demanding and different examiners counting the same section do not always agree, and factors such as disease, nutrition, or pathology can add or obscure bands. Because of this variability it is used as one contributing line of evidence alongside skeletal age indicators rather than a sole determinant.
What makes cementum different from the age markers used at the sternal rib end or cranial sutures?+
Cementum annulation reads a microscopic, tooth-level growth record deposited yearly, while rib-end and suture methods score macroscopic surface changes across a broader age range. Combining a tooth-based estimate with skeletal indicators narrows the estimated age range further than either method alone.
Related terms
- ADBOU Transition Analysis
- A Bayesian software framework (Boldsen, Milner et al. 2002) that combines multiple skeletal age indicators with an adjustable prior age distribution to...
- Cranial Suture Closure
- The progressive replacement of fibrous suture tissue by bone along the joints between skull bones; the Meindl-Lovejoy 1985 system scores ten ectocranial...
- Ectocranial Scoring
- Assessment of cranial suture closure from the outer surface of the skull; slightly later than endocranial closure and more easily assessable on...
- Iscan-Loth Method
- A nine-phase scoring system for the sternal end of the right fourth rib (1984-1985), providing separate male and female reference data for...
- Meindl-Lovejoy Vault System
- A five-site composite scoring system for ectocranial suture closure at midlambdoid, lambda, obelion, anterior sagittal, and bregma sites, derived from the Hamann-Todd...
- Over-50 Ceiling
- The documented failure of most standard skeletal phase methods to distinguish ages above approximately 50 to 55 years with useful precision; a...
- Skeletal Histomorphometry
- Microscopic counting of secondary osteons and fragmentary osteons per unit area of cortical bone cross-section as a supplementary age indicator; requires destructive...
- Sternal Rib End
- The anterior (medial) end of the rib that articulates with the sternum via costal cartilage; its progressive pit formation, wall porosity, and...
- Wormian Bones
- Accessory ossicles (Inca bones) within cranial sutures, particularly the lambdoid; their presence interrupts suture scoring and must be noted before applying Meindl-Lovejoy...