OBJECTIVES: Dental patient-reported outcomes, especially the Oral Health-Related Quality of Life (OHRQoL) construct, are vital for evidence-based dentistry. This construct includes four dimensions (4D): Oral Function, Orofacial Pain, Orofacial Appearance, and Psychosocial Impact. This study updates previous work characterizing 4D OHRQoL impairment among patients in dental hygiene (DH) and dental therapy (DT) settings. METHODS: An expert panel revised previously determined DH and DT patient population groups to align them with current scopes of practice. An updated systematic review was then conducted to incorporate recent studies using the Oral Health Impact Profile (OHIP) to assess 4D OHRQoL in these populations. The search spanned 6 databases from January 1, 2023, to April 16, 2024. RESULTS: The panel identified 20 patient populations, representing the scope of DH and DT practice. The systematic review contained 19 studies (17 from the previous review and 2 new ones). Studies' OHRQoL data covered only 30 % of dental hygiene and dental therapy patient populations identified by the panel. The most frequently studied group was "therapeutic periodontal treatment-patients with periodontitis" (n = 17, 89 %), followed by "oral hygiene instructions-all patients" (n = 13, 68 %). Only four studies provided 4D OHRQoL data, showing the greatest impacts in Orofacial Pain (baseline OHIP: 3.10-4.20
follow-up: 1.52-3.60) and Orofacial Appearance (baseline OHIP: 0.44-2.50
follow-up: 0.91-2.25). Among studies reporting summary OHIP scores only (n = 15), overall OHRQoL impairment ranged from 1.40 to 42.35 at baseline and 1.50-40.56 at follow-up. All studies demonstrated a general trend of reduced OHRQoL impairment over time with treatment. Risk of bias was low, with no evidence of publication bias. CONCLUSION: Current evidence on OHRQoL impairment in DH and DT patient populations is limited, covering only a third of those treated by dental hygienists and therapists. Especially, scarce 4D OHRQoL data prompts the need for more research in this format. Despite these limitations, the findings show promising trends of reduced OHRQoL impairment over time for DH and DT patient populations.