Background: Dental diseases are associated with chronic health conditions and decreased psychological and sociological wellbeing. Young adulthood presents a pivotal stage as dental hygiene behaviors developed and practiced during this time persist into later life. The Theory of Planned Behavior (TPB) is a commonly used theoretical framework to examine intention to engage in dental behaviors. Purpose: To systematically summarize research studies using TPB questionnaires to assess predictive factors of oral hygiene behaviors among young adult populations. Methods: A four-phase article identification process ensured articles met the inclusion criteria. Quality appraisal assessments were used to evaluate questionnaire construction methodology. Results: Twelve articles met the study's inclusion criteria. Each study incorporated supplemental predictive factors such as oral health knowledge and expected social outcomes in addition to the TPB constructs. Discussion: Evidence from this systematic review suggests that TPB is a useful theoretical framework for designing questionnaires that assess dental hygiene behaviors of young adults. Translation to Health Education Practice: Health education specialists should administer oral hygiene behavior surveys that utilize TPB and TPB-related constructs to better understand factors associated with improved intentions toward dental hygiene behaviors among young adults.