The Worst Foods for Orthodontic Patients: An In Vitro Materials Study Determining the Maximum Mechanical Stresses Created by Common Foods

Abstract

Background: Forces placed on orthodontic appliances by certain foods are problematic during orthodontic treatment. There is no evidence to substantiate recommendations given to orthodontic patients regarding safe food consumption.

Purpose: We aimed to create an evidence-based food recommendation guide by comparing forces created by various food samples to the strength of the orthodontic bond.

Research Design: A novel food testing apparatus was designed using a 3D printed testing cube, an orthodontic bracket soldered to a metallic rod, and an Instron Universal Testing machine. The compressive stress created by fifty common food items of various hardness and morphologies was measured. Forty shear bond strength measurements of brackets bonded to extracted lower first premolars were also measured in vitro using the same program. These forces were compared in order to determine which food items are most likely to cause orthodontic bond failures during treatment.

Results: An evidence-based food recommendation chart for orthodontic patients was created that largely mirrors recommendations that orthodontic practitioners give to their patients, with several exceptions.

Conclusion: Food consumption recommendations should be itemized rather than categorical, so as to not limit diets unnecessarily or fail to mention certain problematic food items. The testing apparatus designed in the current study should be used to create a comprehensive food recommendation database for orthodontic patients.