Am J Orthod Dentofacial Orthop
September 2019
Introduction: We sought the 3-dimensional (3D) zone of the center of resistance (ZCR) of mandibular posterior teeth groups (group 1: first molar; group 2: both molars; group 3: both molars and second premolar; group 4: both molars and both premolars) with the use of 3D finite element analysis.
Methods: 3D finite element models comprised the mandibular posterior teeth, periodontal ligament, and alveolar bone. In the symmetric bilateral model, a 100-g midline force was applied on a median sagittal plane at 0.
Objective: This study aimed to (1) evaluate the effects of maxillary second and third molar eruption status on the distalization of first molars with a modified palatal anchorage plate (MPAP), and (2) compare the results to the outcomes of the use of a pendulum and that of a headgear using three-dimensional finite element analysis.
Methods: Three eruption stages were established: an erupting second molar at the cervical one-third of the first molar root (Stage 1), a fully erupted second molar (Stage 2), and an erupting third molar at the cervical one-third of the second molar root (Stage 3). Retraction forces were applied via three anchorage appliance models: an MPAP with bracket and archwire, a bone-anchored pendulum appliance, and cervical-pull headgear.
Aim: To describe a clinical application of a new surgical guide system that uses cone-beam computed tomography (CBCT) images, an implant-positioning program (SimPlant), and stereolithography to make a surgical guide for accurate placement of orthodontic mini-implants.
Methods: A patient who was planning to have orthodontic mini-implant treatment on the posterior maxilla was recruited to assess the feasibility of using CBCT images in an implant-positioning guide program (SimPlant 9.02, Materilise, Leuven, Belgium).