AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 142:481–490 (2010) Brief Communication: The London Atlas of Human Tooth Development and Eruption S.J. AlQahtani, M.P. Hector, and H.M. Liversidge* Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AD, UK KEY WORDS dental; age; estimation; forensic; odontology ABSTRACT The aim of this study was to develop a for all age categories was used to construct the atlas. comprehensive evidence-based atlas to estimate age Tooth development was determined according to Moor- using both tooth development and alveolar eruption for rees et al. (J Dent Res 42 (1963a) 490–502; Am J Phys human individuals between 28 weeks in utero and 23 Anthropol 21 (1963b) 205–213) and eruption was years. This was a cross-sectional, retrospective study of assessed relative to the alveolar bone level. Intraexa- archived material with the sample aged 2 years and miner reproducibility calculated using Kappa on 150 older having a uniform age and sex distribution. Devel- teeth was 0.90 for 15 skeletal remains of age <2 years, oping teeth from 72 prenatal and 104 postnatal skeletal and 0.81 from 605 teeth (50 radiographs). Age categories remains of known age-at-death were examined from col- were monthly in the last trimester, 2 weeks perinatally, lections held at the Royal College of Surgeons of Eng- 3-month intervals during the first year, and at every land and the Natural History Museum, London, UK (M year thereafter. Results show that tooth formation is 91, F 72, unknown sex 13). Data were also collected least variable in infancy and most variable after the age from dental radiographs of living individuals (M 264, F of 16 years for the development of the third molar. Am J 264). Median stage for tooth development and eruption Phys Anthropol 142:481–490, 2010. VC 2010 Wiley-Liss, Inc. Age estimation for humans plays an important role in fields Collection at the Human Origins Group, Paleontol- mass disasters and unaccompanied or asylum-seeking ogy Department, Natural History Museum, London minors in the absence of proper documents. It also con- (Molleson and Cox, 1993), that consists of 15 females, tributes to anthropology and forensic sciences, where age 22 males, and 13 unknown sex (N 5 50); the second was at death is estimated for skeletal remains (Hillson, Maurice Stack’s collection, which is part of the Odonto- 1996). Teeth survive inhumation well and show less vari- logical Collection at the Royal College of Surgeons of ability than skeletal age, and the developing dentition is England (Stack, 1960) made up of 69 males and therefore better than other developmental indicators 57 females (N 5 126). available for age estimation up to maturity (Garn et al., 1960; Demirjian, 1986; Smith, 1991). Humans have two Individuals aged 2–24 years of age. Good quality generations of teeth: the deciduous dentition, which archived dental panoramic radiographs were selected, begins to develop around the sixth week in utero, and with all teeth in focus, of healthy individuals (N 5 528) the permanent dentition, which reaches completion in aged 2–24 years from the Institute of Dentistry, Barts early adult life. This long span of tooth development, and the London School of Medicine and Dentistry. All ra- eruption, shedding, and maturing is an orderly and se- diographs had previously been taken for diagnosis and quential process. Crown or root growth and maturation treatment. The sample was made up of two ethnic stages as well as eruption relative to the alveolar bone groups: about half were white and half Bangladeshi. level can be used to estimate dental age in both living Mean ages of tooth development are not significantly dif- and skeletal remains. (Demirjian, 1986) The aim of this ferent in these groups (Liversidge, 2009). Each chrono- study was to develop a comprehensive evidence-based logical year was represented by 12 males and 12 females. atlas to estimate age using both tooth development and A uniform age distribution was chosen to equalize accu- alveolar eruption for individuals between 28 weeks in racy over all age groups (Konigsberg and Frankenberg, utero and 23 years. MATERIALS AND METHODS Grant sponsor: Ministry of Higher Education, Saudi Arabia (to SJA). Materials *Correspondence to: Dr. Helen Liversidge, Institute of Dentistry, This was a cross-sectional retrospective study of 704 Barts and The London School of Medicine and Dentistry, Queen archived records: radiographs of known age individuals Mary University of London, Turner Street, London E1 2AD, UK. and known age-at-death skeletal remains. E-mail: [email protected] Individuals aged 28 weeks in utero to less than two Received 21 August 2009; accepted 4 December 2009 years of age. All available individuals aged between 28 weeks in utero and 2 years of age were examined DOI 10.1002/ajpa.21258 from two collections of known age-at-death human Published online 22 March 2010 in Wiley InterScience remains detailed in Table 1. The first was the Spital- (www.interscience.wiley.com). VC 2010 WILEY-LISS, INC. 482 S.J. ALQAHTANI ET AL. TABLE 1. Sample and sex distribution for each age group used to develop the atlas of tooth development and eruption Spitalfields Stacks Radiographs Total Age Male Female Unknown Male Female Male Female Male Female Sum Skeletal remains 28 to \32 weeks in utero – – – 8 4 – – 8 4 12 32 to \36 weeks in utero – – – 8 7 – – 8 7 15 36 to \39 weeks in utero – – – 15 15 – – 15 15 30 39 weeks in utero to – – – 1515– – 151530 \1 week after birth 1 week to \3 months 1 7 1 14 11 – – 15 18 34 3 months to \6 months 4 1 1 6 2 – – 10 3 14 6 months to \9 months 3 3 1 1 2 – – 4 5 10 9 months to \12 months 5 – 6 2 1 – – 7 1 14 11 year a 94 4 –––– 9417 Radiographs 21 years – – – – – 12 12 12 12 24 31 years – – – – – 12 12 12 12 24 41 years – – – – – 12 12 12 12 24 51 years – – – – – 12 12 12 12 24 61 years – – – – – 12 12 12 12 24 71 years – – – – – 12 12 12 12 24 81 years – – – – – 12 12 12 12 24 91 years – – – – – 12 12 12 12 24 101 years – – – – – 12 12 12 12 24 111 years – – – – – 12 12 12 12 24 121 years – – – – – 12 12 12 12 24 131 years – – – – – 12 12 12 12 24 141 years – – – – – 12 12 12 12 24 151 years – – – – – 12 12 12 12 24 161 years – – – – – 12 12 12 12 24 171 years – – – – – 12 12 12 12 24 181 years – – – – – 12 12 12 12 24 191 years – – – – – 12 12 12 12 24 201 years – – – – – 12 12 12 12 24 211 years – – – – – 12 12 12 12 24 221 years – – – – – 12 12 12 12 24 231 years – – – – – 12 12 12 12 24 a Sample is 1 year to \2 years, and the same applies to all ages to the age of 24. 2002). Exclusions were the following: retained deciduous (Ac) when the root apex is closed radiographically with tooth, an impacted tooth, or a resorbing deciduous root normal PDL space. associated with a permanent tooth other than its succes- The remaining root and the distal root of molars were sor. Other exclusions were the presence of a developmen- selected when root resorption and formation stages were tal anomaly, a developmental absence of a tooth, or assessed. Modified Bengston’s stages (Bengston, 1935; extracted tooth/teeth. Liversidge and Molleson, 2004) were used in assessing tooth eruption stage in relation to bone level, ranging Methods from occlusal or incisal surface of a tooth below bone for mandibular teeth or above bone for maxillary teeth, at Stage identification was done by the first author alveolar crest, at midway between alveolar bone and (SJA). Tooth developmental and alveolar eruption stages occlusal plane, and at occlusal plane (see Fig. 4). After of the right side of the jaw from each radiograph were assessing the developmental and eruption stages, the identified on a radiographic viewer with the help of a median was identified from minimum to maximum magnifying glass. Isolated teeth for the human skeletal stages for each stage and for each tooth. These were remains collections were observed directly when radio- tabulated for males, females, and combined sex for each graphs were not available. Each developing tooth (crown of the following age groups: the seventh, eighth, and and root) was assessed according to modified Moorrees ninth month of gestation; birth at midpoint of 2 weeks; stages (Moorrees et al., 1963a,b) shown in Figures 1–3. the first, second, third, and fourth 3 months of life; and The last three stages of tooth development (Rc, A 1/2, for each chronological year over the age of 1 up to the and Ac) are differentiated by subtle differences that age of 23 years. Tooth development and eruption stages relate to the dentin edges at the root end, the apex were assessed twice for 15 skeletal remains (150 teeth) width, and the width of the periodontal ligament space and 50 radiographs (605 teeth) at different occasions to (PDL). Root length is complete (Rc) when the dentin determine the intraexaminer reliability calculated using edges are parallel with an open apical end and a wide Kappa. PDL. Apex half (A 1/2) is the stage where the root termi- Each tooth was drawn by hand by the first author nal is maturing by narrowing at the apical end and mak- (SJA) as an international paper size A4 scale using a 1 ing the dentin root ends converge but still having the pigment liner (Staedtler ) size 0.8 on a tracing pad PDL space wide.