ORAL HEALTH IMPACT AMONG PERIODONTAL PATIENTS AT SUPPORTIVE PERIODONTAL CARE: A CROSS-SECTIONAL STUDY Periodontitis is a chronic inflammatory disease that affects the supporting structures of the teeth, leading to progressive attachment loss and bone destruction. It significantly impacts the quality of life of affected individuals. Despite this, there is a lack of research focused on patients in supportive periodontal care (SPC) within periodontal treatment. This study aimed to determine the impact of periodontitis and other possible factors on oral health-related quality of life (OHRQoL) among patients in SPC using the Malaysian version of the Oral Health Impact Profile (OHIP-14). This study included 219 individuals diagnosed with periodontal disease who had completed active periodontal treatment and were now on regular maintenance. All participants completed the OHIP-14 questionnaire, along with socioeconomic and demographic surveys. A calibrated clinician conducted clinical periodontal examinations to evaluate the patients’ current periodontal conditions. The findings indicate that periodontal diseases significantly affect OHRQoL. The OHIP-14 scores were linked to variables such as age, race, educational background, household income, overall health, duration of SPC, and satisfaction levels regarding general oral and periodontal health. The highest OHIP-14 domain scores were for psychological discomfort, followed by functional limitation and physical disability. Discomfort due to food being stuck had the highest mean score of 2.27 ± 1.11, while avoidance of socializing had the lowest mean score of 0.48 ± 0.83. Multiple linear regression analyses highlighted that being Malay, medically healthy, and having a higher education level had a more pronounced impact on OHRQoL. These findings underscore the significant negative impact of periodontitis complications on OHRQoL during SPC, with race, medical status, and education level being critical influencing factors.