It is well recognized that pacifier habit leads to occlusal and orofacial functional changes in children. However, the effects of the interruption of prolonged pacifier habit on the development of the dento-facial complex has not yet been fully characterized. Thus, the aim of this study was to investigate the influence of pacifier removal on aspects of oro-dentofacial morphology and function in preschool children. For that, a pacifier group (n = 28) and a control group (n = 32) of 4-year-old children with and without pacifier habit, respectively, were followed up by a group of dentists and speech therapists at baseline, 6 and 12 months after habit removal. Bite force and lip pressure were assessed using digital systems, and the evaluation of breathing and speech functions was performed using validated protocols, together with the measurements of dental casts and facial anthropometry. The Two-way mixed model ANOVA was used in data analysis. After 12 months, a decrease in malocclusion frequency was observed in pacifier group. Additionally, a change over time was observed in facial, intermolar and palate depth measurements, as well in bite and lip forces and speech function scores, increasing in both groups (p < 0.01). The upper and lower intercanine widths and breathing scores differed between groups at baseline and changed over time reducing the differences. The presence of speech distortions was more frequent in the pacifier group at baseline and decreased over time (p < 0.05). The interruption of pacifier habit improved the maxillary and mandibular intercanine widths, as well as the breathing and speech functions, overcoming the oro-dentofacial changes found.Trial Registration: This clinical trial was registered in the Brazilian Clinical Trials Registry (ReBEC; http://www.ensaiosclinicos.gov.br/), protocol no. RBR-728MJ2.

Objective The aim was to investigate the influence of pacifier removal on the development of masticatory function and taste sensitivity in preschool children.Methods Sixty children (mean age 48.2 months) were divided into two groups: pacifier group (n=28) and a control group (n=32), which were evaluated and followed-up for a period of 12 months (at baseline, 6 months and 1 year). Masticatory and swallowing functions were assessed using the Mastication Observation and Evaluation protocol (MOE) and Orofacial Myofunctional Rating (MBGR), respectively. Detection thresholds for sucrose and urea were measured by staircase method. The two-way ANOVA mixed model was used for time*group interaction analysis.Results MOE scores improved significantly over time in both groups, although a significant difference between groups persisted after 1 year. On the other hand, swallowing scores were significantly different at baseline, but within 1 year the scores were no longer different between groups. Chewing time and the number of cycles were not different between groups and both decreased after 1-year. Sucrose sensitivity was significantly greater in the control group at baseline and changed over time (p<0.05), being no longer different between groups after 6 months. Bitter sensitivity did not differ over time nor between groups.Conclusions Detection threshold for sucrose differed significantly between children with and without pacifier habit at a mean age of 42 months. Total masticatory function did not selfcorrect after sucking habit removal within a one-year period.Clinical relevance Children with pacifier habit showed important changes in masticatory function that did not self-correct 1 year after cessation of the habit, highlighting the need for prevention and habit interruption as early as possible.