Biomimetic Orthodontic treatments: preferences of adult patients and analysis of the willingness-to-pay index

OBJECTIVES: Minimal knowledge is available concerning adult patient preferences and evaluations in terms of biomimetic orthodontic treatments. The first objective of this study was to evaluate the degree of acceptance of an orthodontic treatment accomplished with three different highly aesthetic orthodontic appliances: 1) clear removable aligners, group CA; 2) fixed vestibular appliances with aesthetic ceramic brackets, group FV; 3) fixed lingual appliances with customized brackets, group FL. The second objective was to analyse the strength of preference in a Western population of adult patients, expressed according to the Willingness-To-Pay (WTP) method, against an orthodontic treatment delivered with these appliances. MATERIALS AND METHODS: WTP values were recorded in 83 subjects on the basis of a starting bid of 3,000 £ (one year of therapy) modifiable through increases or decreases (100 £). Data were collected through an individually delivered online questionnaire. Specific information and details regarding the appliances were provided by means of an interactive web-area of the survey. Population characteristics and choices, median and WTP values and associations with socio-demographic parameters (Mann-Whitney and Kruskal-Wallis tests), correlations between variables (Chi-square test in contingency tables) and significant parameters for predicting WTP values obtained in a multiple linear regression model were revealed. RESULTS: The visualization of details about "limitations and complications" associated with the use of the three appliances was most frequent (31% of requests); the other two major areas of interest were "duration of therapy" (21%) and "discomfort" (13%). The appliances preferred by patients for treatment were, in decreasing order, CA (51.2%), FL (28.8%) and FV (20%); the recorded WTP median values were 3,500, 3,000 and 2,000 £ for FV, CA and FL respectively; no significant difference was found by comparing medians in the three groups (Wilcoxon test: p = 0.2254). An annual income higher than 30,000 £ and regular dental check-ups (once/year) were positive predictors (p = 0.0167 and p = 0.0020, respectively) of the WTP values (regression analysis). CONCLUSIONS: Over half the investigated population (51.2%) indicated the removable clear aligner as the preferential choice for a biomimetic treatment. Despite the high aesthetic value of CA and FL, patients didn't show a greater willingness to put efforts and money for a treatment specifically accomplished with one of those appliances.