Assessing the Impact of 2D:4D Ratio on Oral Hygiene Performance and Gingival Health
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 126
- 试验地点
- 1
- 主要终点
- Mean Quigley-Hein Plaque Index Score (Turesky Modification)
研究概览
简要总结
The second-to-fourth digit ratio (2D:4D)-the ratio of the length of the index finger to that of the ring finger-has gained increasing attention as a non-invasive, stable biomarker of prenatal sex hormone exposure. The 2D:4D ratio is believed to reflect the balance of prenatal androgens (especially testosterone) and estrogens. Lower ratios (more masculinized) indicate higher prenatal testosterone exposure, whereas higher ratios (more feminized) are associated with lower testosterone and higher estrogen levels. Research has linked variations in 2D:4D to a broad spectrum of behavioral traits, cognitive abilities, and health outcomes. 2D:4D has been shown to have strong associations with motor performance, especially skills that require fine motor coordination. However, while many studies have examined the role of 2D:4D in sports and cognition, its relationship to health-related behaviors involving motor skills remains underexplored. One such domain is oral hygiene, which requires sustained fine motor coordination-particularly in actions like tooth brushing and flossing. Despite the clear motor demands of such behaviors, the potential connection between 2D:4D and oral hygiene has not yet been systematically investigated. This study aims to fill this gap by exploring the association between the 2D:4D digit ratio and oral hygiene practices.
详细描述
Background and Rationale The second-to-fourth digit ratio (2D:4D)-the ratio of the length of the index finger to that of the ring finger-is a morphological index thought to reflect prenatal sex-hormone exposure. The trait is determined during early fetal development and is generally stable from early childhood into adulthood. Prior research has examined associations between 2D:4D and behavioral, cognitive, and motor outcomes in various populations; however, the relationship between 2D:4D and everyday health behaviors that require fine motor coordination (e.g., tooth brushing and interdental cleaning) has not been comprehensively evaluated. This study is designed to test whether 2D:4D is associated with oral hygiene measures and practices.
Objectives and Hypotheses Primary objective: To evaluate the association between right-hand 2D:4D and dental plaque accumulation as measured by the Turesky Modification of the Quigley-Hein Plaque Index (QHPI) and the Löe-Silness Gingival Index (GI) at baseline and after standardized oral-hygiene instruction.
Secondary objectives: (1) To examine whether sex and hand dominance modify the association between 2D:4D and oral-hygiene outcomes; (3) To explore whether baseline 2D:4D is related to self-reported brushing frequency.
Hypotheses (a priori): Lower 2D:4D (putatively reflecting higher prenatal androgen exposure) will be associated with differences in oral-hygiene performance compared with higher 2D:4D. Direction and magnitude will be tested empirically.
Study Design and Setting This is a single-center, observational study with a baseline assessment and a planned follow-up visit approximately 7 days after standardized instruction. The study will be conducted in the Periodontology Clinic of the Faculty of Dentistry at Istanbul Okan University.
研究设计
- 研究类型
- Observational
- 观察模型
- Other
- 时间视角
- Cross Sectional
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Systemically healthy University graduates or currently enrolled in a university program Presence of 28 natural teeth No orthodontic appliances or crown restorations in the oral cavity Non-smokers No previous oral hygiene instruction from a dental professional Clinical diagnosis of gingivitis
排除标准
- •Presence of any systemic disease or condition that may affect periodontal health Not a university graduate and not currently enrolled in a university program Fewer than 28 natural teeth Orthodontic appliances or crown restorations present in the oral cavity Current smokers Previous oral hygiene instruction from a dental professional Clinical diagnosis of periodontitis
结局指标
主要结局
Mean Quigley-Hein Plaque Index Score (Turesky Modification)
时间窗: Baseline (Day 0) and 1 week after oral hygiene instruction.
Dental plaque will be scored on buccal and lingual surfaces of all teeth except third molars using the Turesky Modification of the Quigley-Hein Plaque Index (scale 0-5; 0 = no plaque, 5 = plaque covering ≥ two-thirds of crown). Scores per tooth will be averaged per participant.
Mean Löe-Silness Gingival Index Score
时间窗: Baseline (Day 0) and 1 week after oral hygiene instruction.
Gingival inflammation will be assessed on buccal and lingual surfaces at mesial, mid-buccal, and distal sites using the Löe-Silness Gingival Index (scale 0-3; 0 = healthy, 3 = severe inflammation with spontaneous bleeding). Scores will be averaged per participant.
次要结局
- Right-hand 2D:4D Digit Ratio(Baseline (Day 0))
- Self-reported Tooth Brushing Frequency(Baseline (Day 0))
研究者
Ekin Besiroglu
Assist. Prof.
Okan University