By understanding the pathogenesis of the disease, the limitations and problems facing the patients, and the side effects of the ... Opportunities abound for dentists to guide these patients toward having and maintaining better oral health. ... The Merck manual of geriatrics. ... Parkinsona#39;s disease in twins: An etiologic study. JAMA 1999; 2811341-346. 20. Lang AE, Lozano A. Parkinsona#39;s disease, second ofanbsp;...