A finite element analysis of the optimal bending angles in a running loop for mesial translation of a mandibular molar using indirect skeletal anchorage

作者：Kim M. -J.; Park J. H.; Kojima Y.; Tai K.; Chae J. -M.^*

来源：Orthodontics and Craniofacial Research, 2018, 21(1): 63-70.

DOI：10.1111/ocr.12216

• biomechanical phenomena
• finite element analysis (FEA)
• indirect skeletal anchorage
• mesial translation of molar
• orthodontic anchorage procedures
• tooth movement techniques

Structured Abstract
ObjectivesTo estimate the optimal bending angles in the running loop for mesial translation of a mandibular second molar using indirect skeletal anchorage and to clarify the mechanics of tipping and rotating the molar.
MethodsA three-dimensional finite element model was developed for predicting tooth movement, and a mechanical model based on the beam theory was constructed for clarifying the force systems.
ResultsWhen using a running loop without bends, the molar tipped mesially 14.4 degrees and lingually 0.6 degrees, rotated counterclockwise 4.1 degrees, and the incisors retracted 0.02mm and intruded 0.05mm. These angles were about the same as those estimated by the beam theory. When the amount of tip back and toe-in angles was 11.0 degrees, mesial translation of the molar was achieved, and incisors retracted 0.10mm and intruded 0.30mm.
ConclusionsMesial translation of a mandibular second molar without any significant movement of anterior teeth was achieved during protraction by controlling the tip back and toe-in angles and enhancing anterior anchorage with the combined use of a running loop and indirect skeletal anchorage.

• 出版日期2018-2