JADA’s October cover story "Tooth Loss, Dementia and Neuropathology in the Nun Study" (
Stein PS, Desrosiers M, Donegan SJ, Yepes JF, Kryscio RJ. JADA 2007;138[10]:1314–22[Abstract/Free Full Text]
) is part of ongoing research and is being used to understand the effect of periodontal inflammation on dementia and Alzheimer disease. It is an excellent example of evidenced-based dental research.
The thrust of the article is to look at the number of teeth, periodontal conditions, other inflammatory conditions and age in educationally matched patients with extremely similar lifestyles. The nun study is an exceptional arena for gathering data.
My problem is that the data gathered and how they are applied can give different results, depending on the point of view of the author and the factual points used. I would like to look at this data from the viewpoint of sleep-disordered breathing, temporomandibular joint (TMJ) disorders and what we know about those disorders.
There was a 1999 article1 from Emory University that showed that sleep-disordered breathing increased in older adults with dentures. An article in The Lancet that was reported on in March 1999 JADA showed apnea was worse (doubled) when patients did not wear their dentures during sleep.2 The function of the oral apparatus is to maintain our airways. Were the increases in dementia in edentulous or nearly edentulous nuns due to periodontal condition, sleep apnea or a combination?
Looking at sleep research, the changes in the cytokine system can be shown to be related to sleep apnea alone, and inflammatory changes in general can relate to oxidative stress from sleep apnea. Shimshak and DeFuria3 showed a 300 percent increase across all fields of medicine in patients with TMJ disorders. Couple this with the National Heart, Lung and Blood Institute4 report on TMJ and Sleep, and one must re-examine the cause of the changes.
Although I was taught that patients always should take their dentures out at night to preserve their bone structure, I have altered my practices and tell patients to keep their dentures in to preserve their airways. In reality, my female patients who were involved in relationships always kept their dentures in at night for cosmetic reasons. They did not want their husbands or boyfriends seeing them without their teeth.
Now we have a group of nuns who have no cosmetic reason to sleep with dentures in and, if they were told to remove them at night, their apnea would increase. There is a positive correlation between untreated apnea and Alzheimer disease and dementia. Short-term memory loss has been shown to be related to sleep apnea as well. Another factor is that the diagnosis of apnea usually is made largely owing to the patient’s snoring being observed by bedmates.
In a nunnery, where each nun has a private cell (this is assumption for this reply only), there would be less chance of sleep apnea, hypopnea or upper airway resistance syndrome being diagnosed, because the snoring does not bother anyone. Women have been underdiagnosed, because the definitions for apnea were made based on research on older, obese men. If you talk to sleep researchers, most male patients are only treated because their wives and girlfriends encourage them to go to the doctor.
TOP
REFERENCES
