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Closure of Maxillary Spaces During Retention JAE HYUN PARK, DMD, MSD, MS, PHD
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linicians frequently observe a relapse of maxillary anterior spacing after orthodontic space closure. Spaces can develop during the retention phase not only between the incisors but distal to the canines, and even between posterior teeth. Patients with maxillary anterior spacing issues may return to the office during retention because small teeth such as peg laterals were never restored as planned, or because the orthodontist did not place a fixed retainer to prevent spaces or midline diastemas from reopening. These patients are generally reluctant to resume fixed appliance treatment. Minor anterior spaces or midline diastemas can be closed using an Essix* appliance, as shown by other authors,1-3 but more generalized or wider spacing will usually require a different approach.4 This article describes a simple modification of a maxillary retainer for closure of reopened spaces.
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Appliance Fabrication The appliance is a modified removable retainer with .028" or .030" anterior and .032" posterior arms. The palatal interproximal margins of the acrylic are removed and polished to enable retraction of the anterior teeth (Fig. 1A,B). The anterior elastics are usually 3/16", 6oz, or 1/4", 6oz, and posterior elastics usually 5/16", 4oz, but their placement and force can be varied as needed for specific situations (Fig. 1C). Most patients find it easier to attach the elastics to the hooks before inserting the retainer, depending on their dexterity and the force level of the elastics. We instruct patients to wear the appliance at all times except while eating or brushing. With good compliance, the spaces will close rapidly, so the patient should be checked every three weeks to prevent overcorrection.
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Fig. 1 A. Modified retainer for maxillary anterior space closure, with anterior and posterior hooks for elastics. B. Patient with anterior and posterior elastics in place. C. Alternative elastic configurations.
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Dr. Park is Associate Professor and Chair, Postgraduate Orthodontic Program, Arizona School of Dentistry and Oral Health, A.T. Still University, 5835 E. Still Circle, Mesa, AZ 85206; and an Adjunct Professor, Graduate School of Dentistry, Kyung Hee University, Seoul, South Korea. E-mail him at
[email protected].
Space Closure For the first one or two months after delivery of the retainer, the space closure will occur mainly between the incisors. Once the anterior spaces have been closed, the appliance’s anterior arms should be removed (Fig. 2A), and closure of spaces distal to the lateral incisors can continue with an elastic worn between the posterior arms (Fig. 2B). If needed, the elastic strength can be increased. After all spaces have been closed, we place both a fixed retainer and a removable Essix or wraparound retainer to prevent relapse. A Hawley retainer is not recommended because the labial bow could cause spaces to reopen between the canines and premolars, especially in first-premolar-extraction cases. If there is insufficient overjet for effective maxillary anterior retraction, the clinician should
consider interproximal reduction and retraction in the mandibular arch before starting space closure in the maxillary arch. When significant maxillary retraction is planned, it is especially important to trim the anterior palatal margin of the removable plate before delivery. REFERENCES 1. Sheridan, J.; Hilliard, K.; and Armbruster, P.: Essix Appliance Technology: Applications, Fabrications and Rationale, GAC International, Bohemia, NY, 2003, pp. 85-94. 2. Sheridan, J.J.; Armbruster, P.; Nguyen, P.; and Pulitzer, S.: Tooth movement with Essix mounding, J. Clin. Orthod. 38:435-441, 2004. 3. Cassarella, D. and Pair, J.: Closure of a minor midline diastema using Essix trays, J. Clin. Orthod. 45:229, 2011. 4. Langlade, M.: Optimization of Orthodontic Elastics, GAC International, Central Islip, NY, 2000, pp. 32-52. *Registered trademark of Denstply Raintree Essix Glenroe, Sarasota, FL; www.essix.com.
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Fig. 2 A. Anterior arms removed after closure of anterior spaces, and single elastic attached between posterior hooks to complete space closure (shown in different patient). B. Spaces distal to lateral incisors closed after three more months of full-time appliance wear.
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