Reliability and Validity of a Lithuanian Version of the Oral Health Impact Profile—A Study in Patients with Stage III–IV Periodontitis

Background and Objectives: The study aimed to translate the original English version of Oral Health Impact Profile (OHIP) into Lithuanian and to assess reliability and validity of the translated instrument (OHIP-Lt) in patients with advanced stages of periodontitis. Materials and Methods: Subjects (N = 67) with stage III–IV periodontitis aged 30–63 years were surveyed by questionnaire and examined clinically. Psychometric analysis included explanatory (EFA) and confirmatory (CFA) factor analyses and psychometric tests. Results: Cronbach’s alpha of the translated OHIP was 0.96. EFA revealed four dimensions which Cronbach’s alpha ranged from 0.75 to 0.96. Construct validity of the four-factor model derived from the OHIP-Lt was supported by findings of CFA (RMSEA = 0.077). The total OHIP-Lt and its subscale scores increased as the patients’ self-rated oral health status changed from healthy to unhealthy. Discriminative validity of the OHIP-Lt was confirmed by its higher scores among patients who had an increased spacing between the maxillary anterior teeth and increased clinical attachment level (CAL 5 mm) compared to those who did not. Conclusions: The translated Lithuanian version of OHIP-Lt was identified as four-dimension inventory. Good reliability and validity of the OHIP-Lt provide the evidence for its further use in study on advanced periodontal disease burden among Lithuanian patients.