Variability of Tooth Formation

Forensic Age Estimation in Unaccompanied Minors and Young Living Adults

“…Perhaps due to the fact that a good part of the third molar formation process occurs once puberty is reached, sexual dimorphism contrary to the rest of the dental maturation processes can be observed, with males reaching the different development stages earlier than females, independently of their ethnic origin. Studies published to date agree in this respect (Arany et al, 2004;Garn et al, 1959;Gunst et al, 2003;Haavikko, 1974;Harris, 2007;Harris & Nortjé, 1984;Köhler et al, 1994;Levesque et al, 1981;Meinl et al, 2007;Orhan et al, 2007;Prieto et al, 2007;Solari & Abramovitch, 2002;Throson & Hägg, 1991;Willerhausen et al, 2001). Studies evaluating third molar development in the maxillary and mandibular arch appear to agree in the greater advance in maturation of maxillary molars versus mandibular ones (UNHCR, 2002;6), (14),(37), Meinl et al, 2007;Orhan et al, 2007;Solari & Abramovitch, 2002;Willerhausen et al, 2001).…”

“…For a long time, and even up to the present day in many parts of the world where birth registers do not exist, dental development is used as a child age indicator, adopted as a biologicallegal indicator. H o w e v e r , a l t h o u g h t h i s m e t h o d i s f a s t , c h e a p a n d n o t v e r y i n f l u e n c e d b y i n t r a -a n d interobserver error, eruption is not a good age indicator when used alone, due to factors like interindividual or populational variation (Garn et al, 1959;Moorees et al, 1963), systemic or local diseases (Ungar, 1937) or the elapsed time without changes (Teivens & Mörnstad, 2001). Numerous authors have investigated the chronology and sequence of eruption in different populations (Foti et al, 2003;Fulton & Price, 1954;Giles et al, 1963;Logan & Kronfield, 1933;Olze et al, 2007;Planells et al, 1993;Saunders et al 1993;Tanguay et al 1984; Van der Linden, 1980).…”

“…Numerous authors have investigated the chronology and sequence of eruption in different populations (Foti et al, 2003;Fulton & Price, 1954;Giles et al, 1963;Logan & Kronfield, 1933;Olze et al, 2007;Planells et al, 1993;Saunders et al 1993;Tanguay et al 1984; Van der Linden, 1980). Some of this research examines the correlation between dental eruption and other development parameters; for example Lewis and Garn (Garn & Lewis, 1959) which evaluates parameters such as somatic and sexual growth, personality and state of health, or Green (Green, 1961) which attempts to establish correlations between dental, skeletal and chronological age and weight and height, finding a stronger correlation between dental and chronological age even than that existing between dental and bone development. Hagg and Taranger (Hagg & Taranger, 1980) study the relationship between dental eruption and maximum puberal growth, finding a low correlation between somatic and dental development.…”

Molar development in common chimpanzees (Pan troglodytes)

“…Hominoid dental development and tooth emergence have historically been valued because they offer insight into theories of life history and phylogeny (Zuckerman, 1928;Krogman, 1930;Schultz, 1935;Bennejeant, 1940;Clements and Zuckerman, 1953;Gavan and Swindler, 1966;Gavan, 1967), as well as the absolute ages of individuals that are still developing their dentitions (e.g., Garn et al, 1959;Bailit, 1976;Dean and Wood, 1981;Smith et al, 1994).…”

Growing up slowly 160,000 years ago

“…There is, however, support for their argument. The absence of a developing wisdom tooth would be unusual today in a 9-year-old modern African child, although we should not forget that mineralization stages and, in particular, eruption ages are notoriously variable (17). Clearly, we must now begin to ask sharper questions about rates of root growth in modern humans and fossil hominins.…”