Clinical Safety Guidelines for Managing Distal Shoe Complications

Soft Tissue Complications and Clinical Decision-Making in Distal Shoe Therapy: A Prospective Clinical Follow-Up Study

Distal shoe space maintainers are the standard of care for guiding the eruption of permanent first molars following the premature loss of the primary second molars. Although this therapy represents established clinical practice, prospective evidence regarding soft tissue complications and predictors of treatment outcomes remains limited. This observational study will prospectively collect clinical outcome data during routine treatment visits. The aims of the study are to characterize patterns of complications, evaluate outcomes related to patient adherence, and identify predictors of treatment success. Ultimately, this study seeks to support the development of standardized strategies for clinical monitoring and complication management.

Study Overview

• Status: Recruiting
• Conditions: Soft Tissue Inflammation; Space Maintainer; Premature Loss of Primary Molars
• Intervention / Treatment: Other: Standard Clinical Practice Regimen

Detailed Description

The premature loss of a primary second molar prior to the eruption of the permanent first molar represents a significant clinical challenge in pediatric dentistry. Without appropriate intervention, the unerupted permanent first molar invariably drifts mesially during its eruptive path, resulting in severe arch length deficiency, impaction of the permanent second premolar, and complex malocclusions. The distal shoe space maintainer is the definitive intervention for these cases; its subgingival guide plane acts as a critical buttress, directing the permanent first molar into its correct anatomical position.

Despite its status as a standard clinical procedure, standardized clinical monitoring protocols and evidence-based complication management strategies remain limited. Current literature is primarily restricted to case reports and small retrospective series characterized by substantial heterogeneity in appliance design, follow-up intervals, and criteria for clinical success. Consequently, existing data offer descriptive or anecdotal observations rather than robust, prospective evidence. This gap in the literature leaves several critical clinical concerns unresolved:

Histological and Soft Tissue Ambiguity: Because the appliance's distal extension penetrates the gingival epithelium, it creates a potential pathway for bacterial ingress. There is a significant dearth of prospective data regarding long-term gingival health, the nature of the epithelial attachment, and the chronic inflammatory response at the subgingival metal interface.

Non-Standardized Complication Management: Clinicians currently lack a universal framework or validated assessment tool for managing prevalent complications, such as localized gingival inflammation, ulceration, appliance fracture, or cement failure.

Uncertain Predictors of Success: In the absence of systematic longitudinal monitoring, it remains difficult to quantify how patient-specific variables-specifically oral hygiene adherence and individual gingival reactivity-influence overall treatment success and post-operative morbidity.

Therefore, this prospective study is essential to systematically investigate soft tissue responses and complication patterns. By documenting these outcomes through standardized follow-up and data collection protocols, this research aims to establish evidence-based clinical guidelines and a decision-making framework to optimize treatment outcomes and minimize patient morbidity.

• Study Type: Observational
• Enrollment (Estimated): 50

Contacts and Locations

• Study Contact: Name: Marcio Guelmann, DDS; Phone Number: 352-273-7635; Email: mguelmann@dental.ufl.edu
• Study Contact Backup: Name: Mi Sook Lee, DMD, MSD, PhD; Phone Number: 352-273-7643; Email: misooklee@ufl.edu

Study Locations

• United States
  • Florida
    • Gainesville, Florida, United States, 32610
      • Recruiting
      • University of Florida
    • Gainesville, Florida, United States, 32610
      • Not yet recruiting
      • Department of Pediatric Dentistry, Universit of Florida, College of Dentistry
      • Contact: Marcio Guelmann, DDS; Phone Number: 352-273-7635; Email: mguelmann@dental.ufl.edu
      • Contact: Mi Sook Lee, DMD, MSD, PhD; Phone Number: 352-273-7643; Email: misooklee@ufl.edu
      • Principal Investigator: Mi Sook Lee, DMD, MSD, PhD
      • Sub-Investigator: Marcio Guelmann, DDS
      • Sub-Investigator: Tyler Chin, DMD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study population consists of pediatric patients recruited from the University of Florida College of Dentistry Pediatric Dental Clinic. Participants are children aged 3 to 9 years, classified as ASA I or II, who require distal shoe therapy as part of their standard clinical care following premature loss of a primary second molar. This population represents a clinical sample of children undergoing established space maintenance procedures under general anesthesia due to behavioral or clinical necessity.

Description

Inclusion Criteria

• Pediatric participants aged 3 to 9 years
• American Society of Anesthesiologists (ASA) Physical Status I or II
• Clinical indication for distal shoe therapy as the standard of care
• Undergoing distal shoe space maintainer placement
• Parent or caregiver able to provide consent and comply with follow-up visits

Exclusion Criteria

• Presence of systemic medical conditions that may affect bone metabolism or wound healing
• Patients unable or unwilling to comply with the planned follow-up schedule (up to 24 months)
• Patients with contraindications to distal shoe therapy based on clinical judgment

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Distal Shoe Therapy Cohort; This cohort includes pediatric patients, aged 3 to 9 years (ASA I or II), for whom distal shoe therapy has been clinically indicated as the standard of care (SOC). Participants undergo routine appliance fabrication and placement as part of their standard clinical care. The cohort will be prospectively monitored during SOC follow-up visits (at 1-week and 3-month intervals) to evaluate soft tissue health, gingival inflammation, and the successful eruption of the permanent first molar. Individual participation typically ranges from 12 to 24 months.

Other: Standard Clinical Practice Regimen; his study involves the prospective observational monitoring of clinical outcomes during standard distal shoe therapy. Research activities consist of systematic documentation of clinical data, including radiographic assessment of the intra-alveolar blade depth measured from the mesial margin of the permanent first molar, standardized gingival health scores, and caregiver-reported compliance. No experimental modifications to the clinical device or surgical procedures are performed, ensuring the study reflects routine clinical practice.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence and severity of soft tissue complications adjacent to the distal shoe appliance	Assessment of the proportion of participants experiencing localized soft tissue complications and the graded severity of such responses. Evaluation includes the presence of gingival inflammation, ulceration, granulation tissue formation, or clinical signs of infection. These complications will be systematically documented during standardized clinical examinations at each follow-up visit. Severity will be categorized using a defined clinical scale (none, mild, moderate, severe). For participants with multiple symptoms, the overall severity will be reported based on the most severe clinical finding to arrive at one aggregated value per participant.	From appliance placement until functional eruption of the permanent first molar (typically 12 to 24 months).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Frequency of missed follow-up appointments per participant	Assessment of patient and caregiver compliance through the systematic tracking of scheduled routine follow-up visits. This measure quantifies the total number of missed appointments during the study period for each participant, reflecting adherence to the prescribed clinical monitoring protocol.	From appliance placement until functional eruption of the permanent first molar (typically 12 to 24 months).
Adherence to oral hygiene instructions based on clinical assessment	Evaluation of patient/caregiver adherence to standardized oral hygiene protocols. Adherence will be assessed during routine follow-up visits and reported as the number of participants who consistently maintain adequate oral hygiene (e.g., meeting predefined clinical criteria for plaque control) throughout the study duration.	From appliance placement until functional eruption of the permanent first molar (typically 12 to 24 months).
Incidence of successful eruption guidance of the permanent first molar	The success of eruption guidance will be determined by verifying the correct anatomical positioning of the permanent first molar. Success is defined by radiographic assessment (bitewing radiographs) and standardized clinical photographs showing the molar in its intended position without impaction or significant mesial drifting. Results will be reported as the number of participants achieving successful eruption guidance.	From appliance placement until functional eruption of the permanent first molar (typically 12 to 24 months).

Collaborators and Investigators

• Sponsor: University of Florida
• Investigators: Principal Investigator: Mi Sook Lee, DMD, MSD, PhD, University of Florida

Publications and helpful links

General Publications

• Brill WA. The distal shoe space maintainer chairside fabrication and clinical performance. Pediatr Dent. 2002 Nov-Dec;24(6):561-5.

Helpful Links

• University of Florida College of Dentistry, Department of Pediatric Dentistry

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): February 1, 2028
• Study Completion (Estimated): February 1, 2029

Study Registration Dates

• First Submitted: February 7, 2026
• First Submitted That Met QC Criteria: February 7, 2026
• First Posted (Actual): February 13, 2026

Study Record Updates

• Last Update Posted (Actual): May 12, 2026
• Last Update Submitted That Met QC Criteria: May 7, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: primary second molar; distal shoe; soft tissue complications
• Other Study ID Numbers: IRB202600105

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: Individual participant data will not be shared to ensure the protection of patient privacy and maintain strict adherence to HIPAA regulations. The research involves sensitive clinical and radiographic data of pediatric participants, which is stored in a secure, encrypted database accessible only to the approved research team. While de-identified aggregate data will be used for publications and presentations, the raw individual-level data is restricted to maintain the highest level of research data integrity and confidentiality.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No