title: Changes in root length from early to mid-adulthood: resorption or apposition?
abstract: A significant number of adults are seeking orthodontic treatment, therefore, it is important to determine the normal changes in root length (resorption or apposition) that occur at this stage of maturation, specifically between early and mid-adulthood. The purpose of the study was to determine on a longitudinal basis the changes in root length between 25 and 45 years of age in a normative untreated population. Two sets of complete mouth surveys were available at early and mid-adulthood, on a total of 26 subjects (12 males and 14 females). Each set consisted of at least 18 periapical radiographs. On each set of radiographs, the roots of 28 teeth were measured including incisors, canines, premolars, and first and second molars, in both the maxillary and mandibular arches. Root length was measured as the perpendicular from the root apex to a line connecting the mesial and distal points of the cementoenamel junction of each tooth. A total of 1456 teeth (1664 roots) were measured; 672 teeth in males and 784 teeth in females. Allowable intraexaminer and interexaminer measurement variability was predetermined at 0.5 mm. Paired and Student t tests were used to determine: (1) whether significant changes occurred with age; (2) whether there were differences between males and females for the incisors, canines, premolars, and molars; and (3) whether there were differences between the right and left sides. Statistical significance was predetermined at P </=.05. The present findings indicated that there were no significant changes in root length for all tooth types evaluated between 25 and 45 years of age, in both males and females. These findings are important for the orthodontist to recognize because they provide some assurance that there is no systematic shortening of root length between early and mid-adulthood.
authors.affiliation: College of Dentistry, University of Iowa, Iowa City 52242-1001, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Bishara
authors.forename: L
authors.initials: L
authors.lastname: Vonwald
authors.forename: J R
authors.initials: JR
authors.lastname: Jakobsen
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D009811:Odontometry / Q000379:methods / Q000706:statistics & numerical data; D011859:Radiography; D015203:Reproducibility of Results; D012391:Root Resorption / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012727:Sex Characteristics; D014092:Tooth Root / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000254:growth & development*