OHIP-14, OQLQ-22 and NRS-10 questionnaires.
pain, Pain, treatment*visit
The scores of the Invisalign group are below those of the brackets group (meaning a better QoL in the Invisalign group), a significant decrease is seen along the appointments for all the sample (OS treatment improves QoL/patients’ satisfaction) as well as a significant association with basal scores (the higher the basal score, the better scores in following appointments). The confidence intervals of the adjusted means clearly overlap at T1; at T2 overlapping is minimal: the difference is almost significant. However, the interaction treatment*appointment is not significant, therefore it is not possible to state that the difference between groups changes significantly between T1 and T2. This is interpreted as there is a significant difference, already present at baseline and maintained along the study. Moreover, the scores significantly decrease along the study (Fig. 
OHIP-14 Questionnaire.The OQLQ-22 results were better in the Invisalign group at all evaluations. The difference in favor of the Invisalign group proved statistically significant at T2 (meaning a better QoL in this group). The scores of the Invisalign group are below those of the brackets group, and a significant decrease along the appointments for all the sample (improve in QoL with treatment and during its course) and a significant association with basal scores (the higher the basal score, the better scores in following appointments) can be noticed.Although there is a net impact of treatment, confidence intervals overlap for all appointments. The interaction treatment*visit is not significant and the difference between groups does not change significantly between T1 and T2. This is interpreted as there is a significant difference, already present at baseline and maintained along the study. Moreover, the scores significantly decrease along the study (Fig. 
OQLQ-22 Questionnaire.The pain intensity scores were lower in the Invisalign group at all evaluations. These differences proved statistically significant at T0 (Fig. 
Pain intensity (NRS-10).The duration of treatment was very similar in both groups, with a mean duration of 12.14 months in the Invisalign group (range 5-16) and 13 months in the brackets group (range 6-18) (