Human tooth movement by continuous high and low stresses

Whitney N. DeForest, Jodi K. Hentscher-Johnson, Ying Liu, Hongzeng Liu, Jeffrey C. Nickel, Laura R. Iwasakif

Research output: Contribution to journalArticle

5 Scopus citations

Abstract

Objective: To compare three-dimensional tooth movements resulting from relatively higher and lower stresses in a split-mouth design. Materials and Methods: Eight volunteers whose maxillary first premolars were removed for orthodontic treatment participated. Each subject's maxillary canines were retracted by randomly assigned constant stresses of 78 kPa and 4 kPa via segmental mechanics. Dental casts depicting 8-10 visits per subject over 84 days and a three-axis microscope were used to measure movements serially. Descriptive statistics and mixed linear modeling were applied for data analyses (α = .05). Results: Teeth moved by 78 kPa had significantly faster (P = .0005) distal movement (0.066 ± 0.020 mm/day) compared to teeth moved by 4 kPa (0.031 ± 0.012 mm/day). Lateral movement and distopalatal rotation were also significantly faster (fourfold and 10-fold, respectively) with higher than with lower stress (P < .0001). Average extrusion-intrusion, crown torque, and tip were small (≤ |0.25| mm, |2.29|°, and |1.98|°, respectively), fluctuated, and not significantly different between high and low stresses. No lag phase of tooth movement was evident. Conclusions: Maxillary canines were retracted faster by 78 kPa than by 4 kPa. Controlled translation was possible with 4 kPa, but 78 kPa outstripped appliance constraints, causing distopalatal rotation.

Original languageEnglish (US)
Pages (from-to)102-108
Number of pages7
JournalAngle Orthodontist
Volume84
Issue number1
DOIs
StatePublished - Jan 1 2014

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Keywords

  • Human
  • Mechanical stress
  • Mechanics
  • Tooth movement

ASJC Scopus subject areas

  • Orthodontics

Cite this

DeForest, W. N., Hentscher-Johnson, J. K., Liu, Y., Liu, H., Nickel, J. C., & Iwasakif, L. R. (2014). Human tooth movement by continuous high and low stresses. Angle Orthodontist, 84(1), 102-108. https://doi.org/10.2319/041113-277.1