The aim of this observational study was to investigate the effect of the menstrual cycle on the manual dexterity of female dentists.

This study was conducted to answer the following question:

- Is there any effect of the menstrual cycle on the manual dexterity of female dentists?

Inclusion Criteria:

• All participants were nulliparous female dentists having a regular menstrual cycle which was confirmed by using a calendar of three consecutive menstrual cycles.
• Their ages ranged from 25 to 35 years old.
• Their BMI was within the normal range (18.5 to 24.9 kg/m²).

Exclusion Criteria:

• Pregnant female dentists.
• Irregular menstrual cycle and any type of hormonal therapy that may affect normal hormonal level fluctuation.
• History of either orthopedic or neurologic diseases causing functional defects of hand strength such as fracture, carpal tunnel syndrome, or De-Quervain's syndrome.
• Upper limb or hand surgery.
• History of systemic diseases like diabetes mellitus.

Forty-five nulliparous female dentists, with at least one year of practice of the manual work, participated in this study. They were recruited from the outpatient clinic of the Faculty of Dentistry, Horus University, and from private dental clinics.