Three-dimensional analysis of maxillary protraction with intermaxillary elastics to miniplates

Abstract

Introduction Early Class III treatment with reverse-pull headgear generally results in maxillary skeletal protraction but is frequently also accompanied by unfavorable dentoalveolar effects. An alternative treatment with intermaxillary elastics from a temporary anchorage device might permit equivalent favorable skeletal changes without the unwanted dentoalveolar effects. Methods Six consecutive patients (3 boys, 3 girls; ages, 10–13 years 3 months) with Class III occlusion and maxillary deficiency were treated by using intermaxillary elastics to titanium miniplates. Cone-beam computed tomography scans taken before and after treatment were used to create 3-dimensional volumetric models that were superimposed on nongrowing structures in the anterior cranial base to determine anatomic changes during treatment. Results The effect of the intermaxillary elastic forces was throughout the nasomaxillary structures. All 6 patients showed improvements in the skeletal relationship, primarily through maxillary advancement with little effect on the dentoalveolar units or change in mandibular position. Conclusions The use of intermaxillary forces applied to temporary anchorage devices appears to be a promising treatment method.

Stability of rapid maxillary expansion and facemask therapy: A long-term controlled study

“…The favorable long-term outcomes in terms of mandibular position in the patients treated with the orthopedic protocol could be associated with changes in the glenoid fossa that have been described previously for chincap therapy 24 and miniplates and Class III elastics protocol. 25 A laminagraphic evaluation of temporomandibular joint changes after chincap therapy showed deepening and widening of the mandibular fossa, and narrowing of the clearance between the condyle and the fossa. 24 No tendency to an increase in the vertical skeletal relationships was recorded in the treated group at either the T2 or T3 observations, in contrast with previous findings by Macdonald et al 8 The use of a correct downward inclination of the extraoral elastics of the facial mask might have accounted for the lack of a bite opening tendency in the treated group.…”

Success rate of miniplate anchorage for bone anchored maxillary protraction

“…19,20 With this approach, an extraoral face mask is no longer needed and intermaxillary traction can be applied 24 hours a day. Preliminary studies based on conventional two-dimensional (2D) cephalometric analysis 21,22 and three-dimensional (3D) virtual treatment outcome analysis 23 showed already very promising results. However, the stability and success rate of miniplate anchorage for BAMP had not been investigated yet.…”

The validity of using surface meshes for evaluation of three-dimensional maxillary and mandibular surgical changes

“…15,16 Some studies have used ÒisolinesÓ to Òquantitatively measure the greatest displacements between points in the 3D surface modelsÓ. 12,17,18 This again provides only one reading of the largest difference between two surfaces.…”