Bone-Screw Anchorage for Pendulum Appliances and Other Fixed Mechanics Applications

Failure rates for stainless steel versus titanium alloy infrazygomatic crest bone screws: A single-center, randomized double-blind clinical trial

“…[18][19][20][21] The most common E-R TADs are made of SS, and they are used as anchorage in the MBS and IZC regions to treat a broad variety of malocclusions. 8,[11][12][13][14][15][16] Most studies of I-R miniscrews had a higher failure rate in the mandible (19.3%) than in the maxilla (12.0%). [18][19][20][21] In comparison, there was no significant difference between the failure rates for E-A BSs: 7.2% for MBS BSs in the posterior mandible 8 compared with 7.0% for IZC BSs in the posterior maxilla ( Figure 8).…”

“…All screws were placed buccal to the roots of the maxillary molars (Figure 4) by the same clinician who had placed .1000 IZC BSs with a well-established, multicenter clinical procedure. [11][12][13][14][15][16] After achieving local anesthesia, a sharp dental explorer was sounded through the soft tissue to mark the desired skeletal site, which is independent of the mucogingival junction ( Figure 6). The type of soft tissue penetrated by the screw tip was scored as either AG or MM.…”

“…All BSs were immediately loaded and reactivated every 4 weeks with prestretched power chains, 17 within the well-established force range for IZC BSs under routine conditions: 8-14 oz (227-397 g or 223-389 cN). [11][12][13][14][15][16] As previously defined, [11][12][13][14][15][16] the treatment force varied within the prescribed range according to the clinician's perception of bone density at the time of BS placement and the specific biomechanics required. All IZC BSs in this study were used as anchorage to retract the entire maxillary arch for at least 6 months ( Figure 7c) to achieve a Class I occlusion ( Figure 7d).…”

“…c Professor Emeritus of Orthodontics and Adjunct Professor of Mechanical Engineering, Indiana University & Purdue University, at the base of the infrazygomatic crest (IZC; Figure 2), with a rotating screwdriver method (Figure 3). [11][12][13] This unique surgical approach resulted in a TAD buccal to the roots of the maxillary molars, which was capable of providing extra-radicular (E-R) anchorage for retraction of individual maxillary teeth or the entire upper arch (Figure 4). Maxillary bone is less dense (Figures 3 and 4) than in the mandible, 8 so the strength of SS may not be necessary for the posterior maxilla.…”

Modern Therapy for Severe Alveolar Ridge Atrophy

“…2Y4 On the other hand, the miniscrew is a modern standard orthodontic anchorage therapy in gaining space or correcting crowded teeth. 5,6 The authors recommend the modern treatment in cases of severe ridge atrophy: the combination of 2 implants between the mental foramina with attachment system overdenture and maxilla preprosthetic surgery with bone screw assists in interim denture fixation.…”