Table 1.

Studies on Parkinson's disease and oral health, available in the international literature.

Publication	Country	Research design	Population	Results of PD patients when compared to controls	OR	95% CI	P
Nakayama et al., 2004 [19]	Japan	Questionnaire survey by mail	104 with PD 191 controls	Gender- and age-adjusted:
				More chewing difficulties	6.0	2.8–12.8
				More denture discomfort	3.9	1.9–8.0
				More edentulousness	3.5	1.8–6.8
				Less daily denture care	10.5	2.9–37.3
				50% swallowing problems
Schwarz et al., 2006 [20]	Germany	Case-control, age-matched	70 with PD 85 controls	Higher scores on indices of the Community Periodontal Index for Treatment Needs (CPITN)			<0.05
Einarsdóttir et al., 2009 [21]	Iceland	Case-control	67 with PD 55 controls	Lower number of teeth			<0.036
				More dental carious lesions			<0.007
				More biofilm	3.13	1.4–6.9	<0.004
				Poorer periodontal health	2.28	1.0–4.9	0.035
				Greater number of cariogenic bacteria in saliva			<0.05
Hanaoka and Kashihara, 2009 [22]	Japan	Case-control, age-matched	89 with PD 68 mild cognitively impaired 60 with ischemic stroke	Lower number of teeth			<0.05
				More dental carious lesions			<0.001
				More deep periodontal			<0.001
				pockets
Bakke et al., 2011 [23]	Denmark	Case-control, age-matched, gender-matched	15 with moderate to advanced PD 15 controls	Overall objective orofacial function			<0.001
				Poorer subjective masticatory ability			<0.001
				Poorer active mouth opening			<0.001
				More negative impact of oral health on daily life			<0.001
Müller et al., 2011 [24]	Germany	Case-control	101 with PD 75 controls	Lower gingival index			<0.001
				Lower frequency of daily tooth brushing			<0.01
				More dental carious lesions			<0.01
				Longer time since last dental visit			<0.001
				Lower salivary flow rate			<0.001
				More gingival recession			<0.001
				More tooth mobility			<0.001
Cicciù et al., 2012 [25]	Italy	Case-control, age-matched	45 with mild to moderate PD 45 controls	More dental carious lesions			not reported
				Higher gingival index			not reported
				Higher sulcus bleeding index			not reported
				Higher biofilm index			not reported
Pradeep et al., 2015 [26]	India	Case-control, age-matched	45 with PD 46 controls	More periodontal pockets			<0.001
				More periodontal attachment loss			<0.001
				Lower gingival index			<0.001
				Lower biofilm index			<0.001
Ribeiro et al., 2016 [27]	Brasil	Case-control	Wearers of complete removable dental prostheses 17 with PD 20 controls	Poorer self-perception of oral health			<0.04
Barbe et al., 2017 [28]	Germany	Questionnaire survey	100 with PD Frequencies compared with results of other studies	Poorer oral health impact profile, among others due to complaints of xerostomia, drooling and dysphagia