An examination of proportional root lengths of the mandibular canine and premolars near the time of eruption.
BACKGROUND
To make treatments more efficient, orthodontists require a more precise means of estimating tooth eruption. The purpose of this article was to extend the information derived from dental staging techniques by incorporating direct measurements of root lengths for 3 mandibular teeth: the canine and the 2 premolars.


METHODS
The full sample consists of 227 panoramic films from 77 female patients and 229 films from 74 male patients treated at a practice in Texas. A subsample of paired preeruption and posteruption films was examined in greater detail (46 subjects for the canine, 42 for the first premolar, and 46 for the second premolar).


RESULTS
Canines will most likely have root length ([root length/total tooth length] × 100) of approximately 70% and premolars will have approximately 65% near the time of alveolar eruption. In addition, the walls of the root canal will probably approach a parallel configuration at the time of eruption.


CONCLUSIONS
The percentage of root length, along with root canal parallelism, should allow improved prediction of eruption timing.
Department of Sociology and Anthropology, University of Texas at Arlington, Arlington, TX 76019, USA. slsmith@uta.edu
Shelley L
SL
Smith
Peter H
PH
Buschang
D000293:Adolescent; D000366:Age Determination by Teeth; D000367:Age Factors; D000539:Alveolar Process / Q000000981:diagnostic imaging; D001641:Bicuspid / Q000000981:diagnostic imaging*; D002648:Child; D003481:Cuspid / Q000000981:diagnostic imaging*; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging*; D009811:Odontometry / Q000379:methods; D011862:Radiography, Panoramic; D019227:Tooth Apex / Q000000981:diagnostic imaging; D019228:Tooth Crown / Q000000981:diagnostic imaging; D014078:Tooth Eruption; D014092:Tooth Root / Q000000981:diagnostic imaging*