Pacific Coast Society of Orthodontists Bulletin Spring 2016 - (Page 42)

Presentation Summary Concepts and Controversies in Contemporary Clinical Orthodontics Dr. Jae Hyun Park PCSO Bulletin Editor Presented by Dr. S. Jay Bowman, Arizona State Orthodontic Association, December 2015. Editor's Note: The Arizona State Orthodontic Association (ASOA) held its 2015 Annual Meeting at the Phoenix Country Club in December, with Dr. S. Jay Bowman as the guest speaker. Because this was an all-day lecture that presented valuable information, I have decided to summarize and share it with our members. Drs. Park and Bowman 42 The Role of Facial Esthetics in Orthodontics Some have alleged that extractions can negatively affect facial profiles, so several studies have concentrated on extraction and facial appearance. One such study conducted at Washington University examined 160 premolar extraction cases and found that 90% of profiles improved or were unchanged.1 Another study conducted at the University of Mississippi compiled 45 cases (15 extractions, 15 non-extractions, and 15 untreated patients) for evaluation by 40 general dentists.2 The goal was to determine the treatment method by examining the facial profile. General dentists were able to identify patients who had had orthodontic treatment in 52% of the cases and patients who had had extraction treatment with 49% accuracy. What this says is that the treatment method cannot be predicted by facial profile. Because the patient is the person actually receiving the treatment, it is important to understand the importance of profiles from his/her perspective. A study conducted at St. Louis University examined 63 borderline extraction and non-extraction patients who were selected by discriminant analysis.3 Each patient evaluated his/her own pre- and post-treatment profiles. The results showed that 50% of nonextraction patients thought treatment had improved their profile; 58% of extraction patients believed the same. At 14 years post-treatment, the same patients were asked to evaluate their frontal facial appearance. Of non-extraction patients, 57% thought treatment had improved their frontal facial appearance; 69% of extraction patients believed the same. Dr. Bowman mentioned the importance of preserving mandibular intercanine width in order to minimize post-treatment relapse. A metaanalysis of intercanine width showed expansion of 1 to 2 mm during treatment, with relapse posttreatment to original dimensions.4 Little et al showed that expansion in early arch development is unstable and relapse can be expected.5 Interestingly, buccal corridors are affected by the flash or lighting effects of photographs. Dr. Bowman showed an example of a patient with and without buccal corridors, taken consecutively with different camera settings. Skeletal Anchorage System: Enthuse to Use but Not Abuse Dr. Bowman recommends a topical anesthetic consisting of 10% lidocaine, 10% prilocaine, and 4% tetracaine, with no epinephrine or phenylephrine (these reduce shelf life). This is followed by an injection with lidocaine 2% with epinephrine 1:100,000 (30 gauge, short needle) to establish patient comfort while maintaining biofeedback. Dr. Bowman uses an appliance he calls the transpalatal arch plus (TPA+). TPA+ is a regular TPA with elastic hooks, supported by temporary skeletal anchorage devices (TSADs). His rationale for using the TPA+ is as follows: 1. Protracts maxillary dentoalveolar complex to Class I. 2. Applies force to molars close to center of resistance. 3. Reduces bite opening by reducing mesial molar tipping (produces bodily movement). 4. Provides skeletal anchorage without the need for compliance. 5. Reduces reliance on Class III elastics (or facemasks). 6. Reduces lingual tipping of mandibular anteriors (instability). 7. Reduces the incidence of mandibular periodontal stripping. 8. Improves predictability of completion to Class I results. PCSO Bulletin  Spring 2016

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Pacific Coast Society of Orthodontists Bulletin Spring 2016