ASSESSMENT OF INTRAORAL CLINICAL SIGNS OF HYPERSENSITIVITY TO 4D NAM™ APPLIANCE IN CLEFT LIP AND PALATE INFANTS: A PROSPECTIVE STUDY

Abstract

Background: our-dimensional nasoalveolar molding (4D NAM) appliances fabricated using thermo-responsive TA-28 (Graphy Inc., Seoul, South Korea) resins enable continuous and controlled force delivery. However, concerns regarding intraoral hypersensitivity in infants remain inadequately explored.

Objective: To evaluate intraoral clinical signs of hypersensitivity associated with 4D NAM appliances in infants with cleft lip and palate.

Methods: A prospective observational study was conducted on 17 infants undergoing 4D NAM therapy. Appliances fabricated using Graphy TA28 were assessed for hypersensitivity using clinical indicators including blanching, erythema, edema, ulceration, and behavioural responses. Evaluations were performed at every 10-day intervals coinciding with sequential tray changes.

Results: No clinical signs of hypersensitivity, including blanching, erythema, edema, or ulceration, were observed at any evaluation point. However, persistent crying was not observed following insertion of subsequent appliances at 10-day intervals, indicating rapid adaptation to the therapy. Feeding tolerance remained satisfactory, shows positive suckling reflex during feeding and all infants accepted the appliances well without interruption of therapy or any adverse clinical events.

Conclusion: The 4D NAM appliances exhibited excellent intraoral biocompatibility, with no evidence of hypersensitivity reactions, supporting their safe clinical use in infants. Although mild transient behavioural discomfort was observed following initial appliance insertion, infants adapted rapidly, and subsequent appliances were well tolerated. These findings suggest that thermo-responsive shape-memory resin is a clinically safe and acceptable material for presurgical infant orthopaedics. As these observations are based on preliminary data, further investigations involving larger cohorts and extended follow-up periods are necessary to validate the long-term safety and clinical performance of this novel material.