The distal shoe space maintainer: chairside fabrication and clinical performance Warren A. Brill, DMD, MS(HYG)
Dr. Brill is in private practice and a clinical associate professor of pediatric dentistry, School of Dentistry, University of Maryland, Baltimore, Md. Correspond with Dr. Brill at firstname.lastname@example.org
The chairside-fabricated distal shoe appliance, with a stainless steel crown as the retainer, is an efficacious and cost-effective appliance for guiding the unerupted permanent first molar into position after premature loss or extraction of the second primary molar. The fabrication technique is illustrated in this case report and data is presented on the success rate of the appliance. (Pediatr Dent. 2002;24:561-565) KEYWORDS: DISTAL SHOE, SPACE MAINTAINER, SPACE MANAGEMENT Received February 26, 2002 Revision Accepted September 5, 2002
he distal shoe space maintainer, as introduced by Gerber1 and extended by Croll,2,3 is a valuable part of the pediatric dentist’s armamentarium, because in those cases where the second primary molar is lost prematurely, it helps guide the first permanent molar into place. In 1973, Hicks outlined in detail the indications and contraindications for the distal shoe appliance, as well as the diagnostic and systemic considerations.4 The indications and contraindications as outlined by Hicks are listed in Table 1. Hicks preferred fabrication of a cast gold appliance, although appliances with attachments soldered to stainless steel crowns or bands were clinically acceptable.4 Twenty years later, Gegenhiemer and Donly described the fabrication of a laboratory-processed distal shoe appliance soldered to a stainless steel crown that required 2 visits by the patient.5 The first was for preparation of the tooth serving as a retainer for the crown and transfer impression for appliance fabrication. Another crown was temporarily cemented and, when the appliance was fabricated and returned from the laboratory, a radiograph was exposed to verify position of the permanent molar before extraction of the nonrestorable primary second molar and immediate cementation of the appliance. There are distal shoe appliance kits available (Dental Supply Co, Covina, Calif; Denovo, Arcadia, Calif) whereby the distal shoe can be fabricated and inserted immediately after extraction of the second primary molar while the patient is in the chair during one visit. These are the same as the design by Gerber, unchanged since their inception.1
Neither Gegenhiemer and Donly nor Hicks reported on the survival rates of the distal shoe. Baroni et al,6 and Qudeimat et al,7 described survival rates for other fixed appliances. These were longitudinal studies of the band and loop and the lingual arch and utilized the life table method to calculate expected appliance longevity. This calculation allows for the pooling of information from cases followed for less than the entire period of observation, thus calculating an average survival rate for the entire sample.8-10 For this study, actual observations in a specific time period are reported rather than a statistical estimation of survival rates. The purpose of this case report is to describe the chairside fabrication of the distal shoe appliance with a stainless steel crown as the retainer and describe the clinical management of the appliance from insertion to removal, including problems requiring intervention and the effect they have on clinical efficacy.
Clinical management/fabrication technique
Indications Figure 1 shows a second primary molar that is nonrestorable and requires extraction. Clinically, the indications for extraction of the second primary molar were those described by Hicks (ie, irreversible pulpitis that was deemed not to be amenable to pulp therapy with a nonrestorable tooth). A radiograph should be taken to verify the clinical impression and ascertain the position of the first permanent molar....