Conversation with Dr. Lo:
He's had local anesthetic resistant patients before so I'm not uncommon, maybe 1-2 per cent.
He says the local injection needle is shorter than the Tuohy needle (1 1/4 inches vs 3 1/2 inches), so what he does is send some more numbing agent down the Tuohy needle when he gets beyond the 1 1/4 inch point during the procedure.
Also, he waits a few minutes for such patients rather than going right in after the local.
He finds that IV meds help the local anesthetic's effectiveness, even a mild dose. He used 2 mg versed before local, and a small dose of fentanyl just before the procedure injection. (He couldn't remember how much but I suspect it was similar to the versed because I wasn't that spacey. I've had fentanyl for procedures before. Though frankly, if I'm not numb it doesn't do much to mask that--as in my angiograms.)
He was looking for a longer needle for the local injection because that also helps numb the path to the cortisone injection site. (Unfortunately they didn't have one there but he managed without it.)
Regarding how many injections per year, he says there is no real rationale for only 3. No long term studies have been done regarding safe amount, but since the amount of steroid used in an injection is so small compared to the amounts people with asthma or arthritis take, there's no real reason to limit injections to three per year. He believes 2-6 per year is safe and he generally does 3-4, spaced apart by a few months. He says he'll only go in within a few weeks if the patient only had partial relief and still has pain in one area.
He suggested that the Santa Theresa Kaiser is more oriented to intervention and they use IV meds in this procedure, he knows the guys in that department and suspects I'd be better served there. Too bad it's a fair distance from me...but it may be worth it if I can't get satisfactory service locally.
Genetic Variations Associated With Red Hair Color and Fear of Dental Pain, Anxiety Regarding Dental Care and Avoidance of Dental Care
Catherine J. Binkley, DDS, MSPH, PhD, Abbie Beacham, PhD, William Neace, PhD, Ronald G. Gregg, PhD, Edwin B. Liem, MD and Daniel I. Sessler, MD
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.
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.