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Improving reliability of permanent tooth staging for dental age estimation using the crown-root ratio method.

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Title: Improving reliability of permanent tooth staging for dental age estimation using the crown-root ratio method.
Authors: Abdul Rahim AH; Department of Oral and Maxillofacial Clinical Sciences, Faculty of Dentistry, Universiti Malaya, Kuala Lumpur, Malaysia. amirhazwan@um.edu.my.; Dental Institute, Queen Mary University of London, London, UK. amirhazwan@um.edu.my., Davies JA; Dental Institute, Queen Mary University of London, London, UK., Liversidge HM; Dental Institute, Queen Mary University of London, London, UK.
Source: International journal of legal medicine [Int J Legal Med] 2026 Nov; Vol. 140 (6), pp. 3993-4001. Date of Electronic Publication: 2026 Jun 05.
Publication Type: Journal Article
Language: English
Journal Info: Publisher: Springer International Country of Publication: Germany NLM ID: 9101456 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1437-1596 (Electronic) Linking ISSN: 09379827 NLM ISO Abbreviation: Int J Legal Med Subsets: MEDLINE
Imprint Name(s): Original Publication: Heidelberg, FRG : Springer International, c1990-
MeSH Terms: Age Determination by Teeth*/methods , Tooth Root*/diagnostic imaging , Tooth Root*/growth & development , Tooth Crown*/diagnostic imaging , Tooth Crown*/growth & development , Dentition, Permanent*, Humans ; Adolescent ; Female ; Male ; Young Adult ; Radiography, Panoramic ; Reproducibility of Results ; Adult ; Child ; Child, Preschool
Abstract: Objective: Root staging for dental age estimation is subjective when no standard reference is available. This study developed a quantitative approach for Moorrees root stages (R1/4, R1/2, R3/4 and Rc) using crown-root ratio (CRR) measurements and stage-specific bounds.
Materials and Methods: The development phase included 269 Malaysian subjects (145 males, 124 females) aged 16-25 years. A total of 1,502 mature permanent mandibular left teeth (I1-M3) were measured on panoramic radiographs using ImageJ software to determine mean CRR values for mature roots (Rc), the fraction stages and stage-specific bounds, where [Formula: see text], [Formula: see text], and lower bound=succeeding stage CRR + 0.01. Sex differences were analysed using independent t-tests. Validation used 161 additional radiographs (78 males, 83 females) aged 3-24 years, with 774 developing and mature permanent mandibular left teeth measured and independently staged according to Moorrees' method. Measured CRR values were compared with stage-specific bounds and considered accurate when within the expected range. Accuracy was calculated as: [Formula: see text].
Results: Mean CRR values ranged from 0.50 to 0.82, with M3 showing the greatest variability. Significant sex differences were observed for C, P1, M1 and M2 (p < 0.05). Overall staging accuracy was 89.9% (84.6%-95.7%) and declined progressively from R1/4 to Rc. M3 (95.7%) and C (91.3%) showed the highest accuracy, whereas I1 (85.7%) and M1 (88.0%) showed the lowest.
Conclusion: The CRR method provides an objective approach for defining Moorrees root stages and improving staging consistency.
(© 2026. The Author(s).)
Competing Interests: Declarations. Ethics approval: Ethics approval was granted by the Medical Ethics Committee, Faculty of Dentistry (IRB Reference Number: DF OS 1909/0042(P)). All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2008 (5). Human ethics and consent to participate: Participants were informed of the potential use of their radiological data for teaching and research purposes, and written consent was obtained from the participants (or their parent or legal guardian in the case of children under 16). Clinical trial number: Not applicable. Financial interests: The authors have no relevant financial or non-financial interests to disclose. Competing interests: The authors declare no competing interests.
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Contributed Indexing: Keywords: Crown–root ratio; Dental age estimation; Moorrees technique; Quantitative method; Reliability; Root staging
Entry Date(s): Date Created: 20260604 Date Completed: 20261012 Latest Revision: 20261015
Update Code: 20261015
PubMed Central ID: PMC13658346
DOI: 10.1007/s00414-026-03861-7
PMID: 42243577
Database: MEDLINE
Description
ISSN:1437-1596
DOI:10.1007/s00414-026-03861-7