Comparison of frictional resistance between passive self-ligating brackets and slide-type low-friction ligature brackets during the alignment and leveling stage.

BACKGROUND: To compare the frictional resistance between passive self-ligating brackets and conventional brackets with low-friction ligature under bracket/archwire and root/bone interface during dental alignment and leveling. MATERIAL AND METHODS: A tridimensional model of the maxilla and teeth of a patient treated with conventional brackets, and slide ligatures was generated employing the SolidWorks modeling software. SmartClip self-ligating brackets and Logic Line conventional brackets were assembled with slide low-friction ligatures, utilizing archwires with different diameters and alloys used for the alignment and leveling stage. Friction caused during the bracket/archwire interface and stress during the bone/root interface were compared through a finite element model. RESULTS: SmartClip and Logic Line brackets with slide elastomeric low-friction elastomeric ligature showed similar frictional stress values of 0.50 MPa and 0.64 MPa, respectively. Passive self-ligating brackets transmitted a lower load along the periodontal ligament, compared to conventional brackets with a low-friction ligature. CONCLUSIONS: Slide low-friction elastomeric ligatures showed frictional forces during the bracket/archwire interface similar to those of the SmartClip brackets, while the distribution of stresses and deformations during the root/bone interface were lower in the passive self-ligating brackets. Key words:Orthodontic friction, finite element analysis, orthodontic brackets, orthodontic wires.

Treatment of Class III malocclusion using Hybrid Hyrax, Face Mask and Alt-RAMEC Protocol: A Case Report in a Latin-American patient.

The management of Class III malocclusion is one of the greatest challenges of orthodontics. Current treatments offer the possibility of using direct skeletal anchorage to improve clinical outcomes. This case shows the results of using a Hyrax hybrid palatal anchorage, Alt-RAMEC (Alternate Rapid Maxillary Expansion and Contraction protocol) and a facemask to treat a maxillary hypoplasia Class III malocclusion in a Latin-American patient. The appliance design and the protocol used are widely described. Clinical and cephalometric results suggest that it is a good treatment option for this Latino patient, with moderate malocclusion and limitations in the dental anchorage. Key words:ALT-RAMEC, Angle Class III, malocclusion, maxillary expansion, mini-screws, orthodontic anchorage, TADs.