BACKGROUND: Red hair color is caused by variants of the melanocortin-1 receptor 
(MC1R) gene. People with naturally red hair are resistant to subcutaneous local 
anesthetics and, therefore, may experience increased anxiety regarding dental 
care. The authors tested the hypothesis that having natural red hair color, a 
MC1R gene variant or both could predict a patient's experiencing dental 
care-related anxiety and dental care avoidance.
METHODS: The authors enrolled 144 participants (67 natural red-haired and 77 
dark-haired) aged 18 to 41 years in a cross-sectional observational study. 
Participants completed validated survey instruments designed to measure general 
and dental care-specific anxiety, fear of dental pain and previous dental care 
avoidance. The authors genotyped participants' blood samples to detect variants 
associated with natural red hair color.
RESULTS: Eighty-five participants had MC1R gene variants (65 of the 67 
red-haired participants and 20 of the 77 dark-haired participants) (P < .001). 
Participants with MC1R gene variants reported significantly more dental 
care-related anxiety and fear of dental pain than did participants with no MC1R 
gene variants. They were more than twice as likely to avoid dental care as were 
the participants with no MC1R gene variants, even after the authors controlled 
for general trait anxiety and sex.
CONCLUSION: Dental care-related anxiety, fear of dental pain and avoidance of 
dental care may be influenced by genetic variations.
CLINICAL IMPLICATIONS: Dentists should evaluate all patients, but especially 
those with naturally red hair, for dental care-related anxiety and use 
appropriate modalities to manage the patients' anxiety.