Pacific Coast Society of Orthodontists Bulletin Spring 2014 - (Page 18)

S E E ASS O N EEDD S A O N Practitioner's Practitioner's Corner Corner Use of the XBOW™ AppliAnce Vs. the FORSUS™ AppliAnce for clAss ii correction Dr. terry McDonAlD interViews Dr. cArlos flores-Mir TERRY MCDONALD (TM): Would you please briefly describe the construction of the Xbow appliance and how it is used in Class II treatment? When might the Xbow appliance be clinically indicated? M Dr. McDonald Dr. Flores ultiple treatment modalities using functional appliances are being promoted for correction of Class II malocclusions. Some of these promotional claims are supported by scientific evidence; most aren't. Sorting through the variety of these appliances can be confusing in terms of their impact on both a desirable solution to the malocclusion and to time taken to achieve a satisfactory result. The interviewee for this issue of the Bulletin, Dr. Carlos Flores-Mir, is a contributing author to an article published in the May 2013 issue of The Angle Orthodontist, wherein two compliance-free Class II correctors were statistically evaluated as to their treatment length and incisor proclination on two consecutively treated samples of patients (one with the Forsus appliance and one with the Crossbow [Xbow] appliance). Dr. Flores-Mir explains the construction of the Xbow appliance and offers his candid opinions as to the methodology and results of the comparison study. Dr. Flores completed his dental training in 1994, and his orthodontic training in 1998, both at Universidad Peruana Cayetano Heredia in Lima, Peru. He held various academic positions in Peru from 1998 to 2002 before moving to Canada for a three-year postdoctoral fellowship at the University of Alberta, where he took a full-time faculty position upon completion of his fellowship. He remains there today as Head of the Division and Director of the Orthodontics & Orthodontic Program, University of Alberta, positions he has held since April 2010. He has published over 120 peer-reviewed articles, is a recognized international speaker, and is a member of the Royal College of Dentists of Canada, the AAO, PCSO, and the Northeast Component of the Edward H. Angle Society. His email address is 18 CARLOS FLORES (CF): The Xbow appliance itself is a combination of pieces that most orthodontists should be comfortable with. For those who have used lingual arches, palatal expansion appliances, and Class II fixed-type springs (either Esprit™ or Forsus), the learning curve should be short (Figures 1-4). The palatal expansion component, most commonly a Hyrax-type expander, serves two purposes: firstly, to provide a platform to dissipate the fixed spring-delivered force among the included maxillary posterior teeth without straining the anterior teeth (more about this concept below), and secondly to expand the palate when required. Relative palatal constriction, either dentally and/ or skeletally, is common in Class II malocclusions. Timing of the expansion will be discussed below. Occlusal stops for the upper second molars, when erupted, are recommended to prevent overeruption and assist in avoiding the tendency for intrusion of the upper first molars. The lingual arch (Triple "L" Arch™) features a few extra components. First, the buccal segment is contoured 5 mm away from the buccal surfaces of the premolars. This bend provides a railing in which the Class II fixed corrector can move back and forth, thus allowing mandibular functional movement to be minimally restricted. Anteriorly, the labial portion is closely adapted to the labial aspect of the mandibular incisors. This anterior aspect of the labial bow, plus the anterior aspect of the lingual arch, are in close contact with the mandibular incisor crowns, serving as a mechanism to assist in reducing excessive incisor proclination during Class II correction. The other extra components are a series of occlusal stops that should be bonded to at least two premolars and, if available, both mandibular second molars. These will serve as extra support to better distribute the spring-generated forces among the mandibular teeth and, in the case of mandibular second molars (if already erupted), to avoid over-eruption and/or intrusion of mandibular first molars and to function as additional anchorage. With this overall mandibular design, the spring force is delivered to the banded mandibular first molars and bonded mandibular first premolars, and indirectly to the mandibular incisors by the lingual arch. The sizes of the wires for appliance construction are: lower 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