Related Experiment Video
Updated: Nov 10, 2025
07:17
Studying Orthodontic Tooth Movement in Mice
Published on: August 2, 2024
1.2K
Posterior Mandibular Displacement-A Systematic Review Based on Animal Studies
Ioannis Lyros1, Miltiadis A Makrygiannakis1, Theodoros Lykogeorgos2
1Department of Orthodontics, School of Dentistry, National and Kapodistrian University of Athens, 11527 Athens, Greece.
Animals : an Open Access Journal From MDPI
|April 3, 2021
Summary
Posterior mandibular displacement in animal studies restricted growth and altered jaw structure. These changes persisted but the mandible eventually resumed its natural growth pattern, indicating potential for future research.
Area of Science:
- Orthodontics and Dental Research
- Craniofacial Biology
- Animal Models in Biomedical Research
Background:
- Treating extreme mandibular growth (protrusion) presents significant clinical challenges.
- Previous animal studies on mandibular retraction have yielded contradictory findings.
- Understanding the effects of mandibular displacement is crucial for developing effective treatments.
Purpose of the Study:
- To systematically review measurable alterations in the mandible and condyle following posterior retraction in healthy rats or rabbits.
- To consolidate existing evidence on the anatomical and morphological changes induced by mandibular displacement in animal models.
Main Methods:
- A comprehensive literature search was conducted across PubMed, Scopus, and Web of Science up to October 2020.
- Study eligibility was assessed using the PICOS framework.
- Risk of bias was evaluated using SYRCLE's tool for assessing bias in animal intervention studies.
Main Results:
- Mandibular retraction led to a more posterior condylar position and distal molar occlusion.
- Anteroposterior mandibular growth was restricted bilaterally; condylar process height decreased, and angulation increased.
- Condylar neck thickening, posterior flattening, longer coronoid process, and increased retromolar density were observed.
- No significant differences were found in ramus height or intercondylar distance.
Conclusions:
- Posterior mandibular displacement induces significant, persistent morphological changes in the mandible and condyle in animal models.
- These alterations suggest a potential for growth restriction but the mandible eventually reverts to its inherent growth pattern.
- The timing and properties of applied forces may influence temporomandibular joint (TMJ) outcomes and treatment stability.
- Further well-designed, long-term studies are needed to clarify the long-term effects and clinical implications of posterior mandibular displacement.
