Purpose <p>The goal is to assess long-term oral health-related quality of life in adults who had previously undergone compensatory orthodontic treatment for class&#xa0;III malocclusion and to identify associated factors.</p> Methods <p>A total of 26&#xa0;patients who underwent treatment by dental compensation more than 5&#xa0;years ago were followed for an average of 14&#xa0;years and were evaluated using cephalograms, photographs, the Oral Health Impact Profile (OHIP)-14 questionnaire, and self-perception questions on treatment stability. Poisson regression was used to analyze the association between quality of life and the stability of class&#xa0;III treatment, considering posttreatment cephalometric measurements, sex, posttreatment age (T2), treatment and posttreatment duration, use of retainers, tooth extractions, gingival recession, and clinical changes in incisor alignment.</p> Results <p>The median OHIP-14 score was 3 (range 0–8.5), indicating a&#xa0;good level of quality of life over the long-term. In all, 30.76% of patients reported minor worsening in treatment results after its completion. When asked to identify the observed changes that occurred after treatment, whether in the teeth, face, or both regions, 80% associated the worsening with the dental region. Of these, 90% reported willingness to undergo orthodontic retreatment. Only 12% of the variation in OHIP-14 scores was attributed to the chosen predictor variables, and none of the analyzed variables showed a&#xa0;significant association with quality of life (<i>p</i> = 0.20–0.99).</p> Conclusion <p>Adults with class&#xa0;III malocclusion subjected to treatment with dental compensation reported a&#xa0;good OHRQoL in the long-term, even in the presence of minor posttreatment changes. Cephalometric changes, clinical and assessed demographic factors did not significantly impact quality of life.</p>