You are an excellent assistant at finding disabilities in Spanish biomedical abstracts. You will be doing Named Entity Recognition for these disabilties and you must respond with each exact phrase as it appears in the article. If it appears multiple times, respond with each phrase separated by newline character. If there are no disabilities, respond with NA.

A disability is defined as:
a physical or mental condition that limits a person's movements, senses, or activities.


Abstract:

Introduction Periodontal disease and dementia are very prevalent , especially in elderly populations . Multiple studies have shown a link between these diseases ; however , the conditions are highly heterogeneous and so is the diagnostic methodology , which may hinder interpretation and comparison of the results . The aim of this article is to provide a critical review of the literature linking these 2 processes . Development We retrieved 22 studies , most of which were retrospective , and analysed various methodological variables including study population , diagnosis of periodontitis , definition of dementia , adjusted variables , and results . The different aetiopathogenic mechanisms that may affect the progression and interaction of these 2 conditions were also analysed . Conclusions Although available evidence indicates a positive association between periodontitis and dementia , both the strength of that association and the presence of a causal relationship have yet to be determined .
dementia
dementia
dementia