This site became the new on June 19th. Learn more.
Show more Menu IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu IMPORTANT: Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu
Give us feedback

Periodontal Ligament Stress Level and Tooth Movement

This study has been completed.
Information provided by:
University of Alberta, Graduate Orthodontic Program Identifier:
First received: December 21, 2004
Last updated: June 28, 2010
Last verified: June 2010

Orthodontic treatment requires application of force systems to individual teeth or groups of teeth, which results in a cellular response with periodontal ligament (PDL) and alveolar bone remodeling. The forces applied must be of sufficient magnitude and duration to exceed the normal physiologic threshold associated with daily oral function. Excessive force levels will result in areas of tissue necrosis with delayed tooth movement and increased risk of root resorption. Although orthodontic tooth movement is achieved in a large segment of the population, the optimum force level has not been defined. The optimum force for tooth movement depends on individual root geometry as well as biologic characteristics of surrounding tissue including bone density, periodontal thickness, and fluid dynamics.

Because experimental and clinical techniques are generally limited to known complex force systems, biomechanical modeling has become a necessity. Such models must be validated with well-controlled clinical studies that evaluate orthodontic tooth movement over an extended distance. The ultimate goal would be development of a computer simulation model to predict tooth movement in the clinical setting.

The primary objective of this study is to test controlled clinical data with a biomechanical model of the tooth and supporting tissues for distal movement of the human maxillary canine tooth (of known root geometry) in response to various 3D force systems that produce different levels of stress in the supporting tissues. Secondary objectives include evaluation of rate of bodily tooth canine movement with two known compressive stress levels (13 and 22 kPa), evaluation of three different reference systems to measure rate of tooth movement, and evaluation of an implant placed in the roof of the mouth (palatal implant) for orthodontic anchorage in adolescent patients.

The rate of translation (bodily) tooth movement of the maxillary canine tooth will be significantly greater with 22kPa compared to 13kPa compressive stress applied to the periodontal ligament, and this difference can be predicted by appropriate mathematical/numerical models of the tooth and supporting tissues.

Condition Intervention Phase
Malocclusion, Angle Class III Procedure: Two different loop designs which deliver distinctive forces Phase 1

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Single
Primary Purpose: Treatment
Official Title: Clinical/Numerical Study of the Effects of Periodontal Ligament Stress Level on the Rate Bodily Tooth Movement

Further study details as provided by University of Alberta, Graduate Orthodontic Program:

Primary Outcome Measures:
  • Rate of space closure

Estimated Enrollment: 20
Study Start Date: March 2004
Study Completion Date: November 2005
Primary Completion Date: November 2005 (Final data collection date for primary outcome measure)
  Show Detailed Description


Ages Eligible for Study:   12 Years to 16 Years   (Child)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Female adolescent (12-16 years old) orthodontic patients requiring upper first premolars extractions for overjet reduction.
  • Participants will be healthy and not taking any medications.
  • All participants will have healthy periodontal tissues and good oral hygiene.

Exclusion Criteria:

  • Patients with medical contraindication for placement of a palatal implant.
  • All candidates who admit to tobacco utilization will be excluded.
  • Patients requiring lower dental extractions will also be excluded.
  • Pregnant patients or patients planning pregnancy will be excluded.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00099814

Canada, Alberta
Orthodontic Clinic - Department of Dentistry - University of Alberta
Edmonton, Alberta, Canada, T6G 2N8
Sponsors and Collaborators
University of Alberta, Graduate Orthodontic Program
  More Information

Responsible Party: Joanne Lafrance, research assistant, University of Alberta, Graduate Orthodontic Program Identifier: NCT00099814     History of Changes
Other Study ID Numbers: GOP-UA-CT-01
Study First Received: December 21, 2004
Last Updated: June 28, 2010

Keywords provided by University of Alberta, Graduate Orthodontic Program:
tooth movement
clinical trial

Additional relevant MeSH terms:
Malocclusion, Angle Class III
Tooth Diseases
Stomatognathic Diseases
Jaw Abnormalities
Jaw Diseases
Musculoskeletal Diseases
Mandibular Diseases
Maxillofacial Abnormalities
Craniofacial Abnormalities
Musculoskeletal Abnormalities
Stomatognathic System Abnormalities
Congenital Abnormalities processed this record on September 21, 2017