En-masseretraction with a preformed nickel-titanium and stainless steel archwire assembly and temporary skeletal anchorage devices without posterior bonding

Abstract

ObjectiveTo evaluate the therapeutic effects of a preformed assembly of nickel-titanium (NiTi) and stainless steel (SS) archwires (preformed C-wire) combined with temporary skeletal anchorage devices (TSADs) as the sole source of anchorage and to compare these effects with those of a SS version of C-wire (conventional C-wire) for en-masse retraction.MethodsThirty-one adult female patients with skeletal Class I or II dentoalveolar protrusion, mild-to-moderate anterior crowding (3.0-6.0 mm), and stable Class I posterior occlusion were divided into conventional (n = 15) and preformed (n = 16) C-wire groups. All subjects underwent first premolar extractions and en-masse retraction with pre-adjusted edgewise anterior brackets, the assigned C-wire, and maxillary C-tubes or C-implants; bonded mesh-tube appliances were used in the mandibular dentition. Differences in pretreatment and post-retraction measurements of skeletal, dental, and soft-tissue cephalometric variables were statistically analyzed.ResultsBoth groups showed full retraction of the maxillary anterior teeth by controlled tipping and space closure without altered posterior occlusion. However, the preformed C-wire group had a shorter retraction period (by 3.2 months). Furthermore, the maxillary molars in this group showed no significant mesialization, mesial tipping, or extrusion; some mesialization and mesial tipping occurred in the conventional C-wire group.ConclusionsPreformed C-wires combined with maxillary TSADs enable simultaneous leveling and space closure from the beginning of the treatment without maxillary posterior bonding. This allows for faster treatment of dentoalveolar protrusion without unwanted side effects, when compared with conventional C-wire, evidencing its clinical expediency.

A New Designed Expander Supported by Spike Miniscrews With Enhanced Stability

“…12 With the better stability and the less stress concentration than conventional screws, spike screw could be used in expansion periods without loosening. Moreover, compared with another kind of high stability sand blasted, large grit with acid-etched surfacetreated screw C-implant, 13 the spike screw do not need 4 weeks healing time, because it does not need osseointegration. Over 3.5 mm in diameter, tissue punching device, however, is necessary for placing 5 mm in diameter washers during spike screw application.…”

Finite element study of controlling factors of anterior intrusion and torque during Temporary Skeletal Anchorage Device (TSAD) dependent en masse retraction without posterior appliances: Biocreative hybrid retractor (CH-retractor)

“…The CHretractor was developed, which combines the anterior NiTi sectional and posterior SS archwires, using gable bends for effective control of the anterior teeth. 8 Without a gable bend, a retraction force (F H ) generates a clockwise moment (M FH ), because the force vector passes below the center of resistance (CR) of the six anterior teeth ( Figure 6A). This moment leads to anterior torque loss (see 08 gable bend on Table 4) and an extrusion tendency of anterior teeth (see 08 gable bend on Table 2).…”

“…In a previous study, 8 the clinical efficiency of the preformed SS C-wire was reported for the treatment of dentoalveolar protrusion patients who have stable Class I molar relationships. With the CH-retractor, simultaneous alignment, leveling, and space closure are possible from the day appliances are placed.…”

Gene Profiling of Bone around Orthodontic Mini-Implants by RNA-Sequencing Analysis

“…The development of temporary skeletal anchorage devices (TSADs) in orthodontics has made the mechanics of treatment simpler and more effective than conventional techniques [ 1 – 3 ]. Orthodontic mini-implants, which are generally made of a titanium alloy, are cylindrically shaped with a diameter of 1.5–2.0 mm and a length of 6.0–9.0 mm [ 4 ].…”

“…The known risk factors for failure are root proximity, insertion site, and inflammation of the peri-implant soft tissue. Many attempts have been made to increase the survival rate of mini-implants [ 1 – 3 , 9 ]. Studies have shown that the healing period between mini-implant insertion and orthodontic force application is not critical.…”