Pacific Coast Society of Orthodontists Bulletin Spring 2014 - (Page 38)

SUMMARY ANNUAL SESSION Miniplate Anchorage for Midface Protraction in Class III Patients and Molar Distalization in Class II Malocclusions Presented by Dr. Hugo De Clerck at thePCSO Annual Session, October 19, 2013. Summarized by Dr. Bruce P. Hawley, PCSO Bulletin Northern Region Editor. M iniplates are better at resisting high discontinuous forces than are miniscrews, and they can be used for intermaxillary orthopedic traction in the growing Class III patient. Because successful Class III orthopedics often result in a dental Class II relationship, miniplates are also used as anchors in order to achieve a Class I posterior occlusion during later comprehensive orthodontic intervention. of attached gingiva. In the maxilla, the hook exits in the region superior to the crowns of the upper permanent first and second molars, and in the mandible it exits inferiorly to the crowns of the lateral incisors and canines. Dr. De Clerck likes to see the patient 10 days post-op in order to provide oral hygiene instruction, but the initial traction is not begun until two to three weeks post-op. Dr. De Clerck MINIPLATE ANCHORS Primate studies have demonstrated that facial sutures respond like periodontal ligaments under pressure. Anteriorly directed forces to the midface in primates show sutural distractions and changes in the position and growth of the midface. Delaire facemasks have been used clinically since the 1960s, with generally 1 to 2 mm of downward and forward maxillary changes and counterclockwise rotation of the mandible commonly seen. Less skeletal response is observed with relatively increasing age, and it has long been posited by many practitioners that facemask therapy is more effective following rapid maxillary expansion (RME). Bone-anchored maxillary protraction (BAMP) uses Bollard miniplates, which have three holes for maxillary units and two holes for mandibular units (all the holes are in a straight line on the plates). At the end of the miniplate opposite the holes is a hook, which is the only portion that is exposed intraorally. The miniplates are placed bilaterally in a vertical orientation by the oral and maxillofacial surgeon at the zygomatic crest in the maxilla and on the mandibular body mesial to the lower permanent canines. In order to reduce the possibility of localized infection, the hooks should exit in the areas 38 MOLAR DISTALIZATION The maxillary miniplates can be used in Class II cases to achieve Class I molars, including those with maxillary arch length deficiency, by distalizing the canines through the second molars with sliding coil mechanics off the miniplate. Remember that the miniplate is anchored superiorly to the roots of the molar teeth, so it is possible to move the teeth without interference and without the orthopedic effect of Class III elastics, which may have been used previously in the case. A closed nickel-titanium (NiTi) coil spring is attached to a sliding hook mesial to the first premolar brackets. Steel ligatures are placed on the distal wings of the first and second premolar brackets in order to prevent rotation. The maxillary canines are not yet bracketed, and self-ligating brackets are not very effective here. Use a maximum of 150 g of traction between the sliding jig and the miniplate, with the stretched coil spring (and not an elastic). This is a low-friction full-time system, and it often can assist in avoiding the need for maxillary first premolar extractions in many maxillary deficiency cases. Bite opening can sometimes take place, and the unbracketed canine follows the first premolar distally. After the premolars and molars have retracted fully, the roots of the canines need to be distalized in order to avoid tipping, which frequently occurs. In order to avoid anchorage loss, Dr. De Clerck PCSO BULLETIN * SPRING 2014

Table of Contents for the Digital Edition of Pacific Coast Society of Orthodontists Bulletin Spring 2014

A Magical, Spooky, International, Educational Time in Anaheim
New Columns
View From The Top: President’s Perspective
AAO Council on Scientific Affairs (COSA) Report
AAO Trustee Report
ABO Update
How To Save a PCSO Bulletin Article as a .PDF File
The Importance of Healing
Incoming and Outgoing Radiographs
Resident Spotlight: A.T. Still University, Arizona School of Dentistry & Oral Health Postgraduate Orthodontic Program
Use of the XBOW™ Appliance Vs. the FORSUS™ Appliance for Class II Correction
Advanced Research Avenues at the Roseman University of Health Sciences Orthodontic Program
Dr. Gerald Nelson
The Interdisciplinary Team: Managing Patients with Impacted or Ectopically Positioned Teeth
Miniplate Anchorage for Midface Protraction in Class III Patients and Molar Distalization in Class II Malocclusions
Achieving Financial Independence: A New and Younger Members Featured Lecture
The Role of Orthodontics in Trauma Management
Converting a Tube

Pacific Coast Society of Orthodontists Bulletin Spring 2014