## 1 Introduction
### An Overview of Altmetric  
The flow of information among researchers and scholars has undergone a major change over the past few decades. In the \"Social Web\", scholars can still cite a paper, but can also upload it on their website, Tweet it, bookmark it, blog it, download it, share it or post an online review. The general public can also react to scientific findings in an easy and fast way, thanks to the wide dissemination of social media platforms and their easy accessibility. Online activity surrounding a published item can be tracked and can help to define the impact of an article in a different, broader and updated way [6]. When the impact of research output on social networks is assessed, it should be considered that the general public could have limited knowledge on a large number of scientific topics. Altmetric (Altmetric LLP, London, UK) is an altmetrics aggregator that tracks the online activity about a published item on social media (Facebook, Twitter, Blogs, Google+); mainstream media (the New York Times, The Guardian); scientific media (Scientific American, New Scientist); online reference managers (Mendeley, CiteULike). A specific algorithm calculates the Altmetric Attention Score (AAS) of a published item, based on its mentions in the different Altmetric resources [7]. Additionally, Altmetric generates a graphic summary of the impact of the article in which the different colors represent a different altmetric resource (Figure 1), allowing the reader to quickly assess which resources contributed the most to the global score. Altmetric has already been implemented by many publishers in the scientific field. Altmetric is a subscription service that provides all the services and tools of the application to customers. Through the Dimensions app it is possible to retrieve the AAS and other basic Altmetric data free of charge [1]. Based on AAS, the reader can filter published articles and detect which items are provoking greater online engagement [8]. According to what Elmore reported in 2018, many young researchers are already accustomed to disseminating their publications through social media platforms [9]. It should be remarked that most funding institutions, such as the US National Science Foundation, are currently expecting that the funded scientific projects have to be relevant from a scientific standpoint but also to present a social impact. According to some authors, Altmetric can not only track the online dissemination of research on social and mainstream media, but can also play a role in the definition of its social impact [10]. The potential for manipulating data to obtain better ratings is one of the key issues with Altmetric. The manipulation of metrics based on social media is a special problem because of the accessibility of these platforms and the existence of spam providers that make profits selling votes or tweets from registered users. By locating. Altmetric claims to employ a special algorithm that can identify fabricated attention patterns or spotting social media automation tools, in order to reduce the impact of such manipulation [11]. The tendency of Altmetric to favor funny or sexually explicit titles or content might be a disadvantage. According to [PERSON] and [PERSON] (2017), some title qualities or having an intriguing title may also affect the chance of receiving a high AAS [12]. Because of Altmetric's unique characteristics and the vast potential public reach of social media, the researcher may be tempted to intentionally or unintentionally misreport the results of their research in order to affect the effect it may have on social media dissemination. A reliability check can be performed manually on every published item by the individual researcher since in the Altmetric pay per use App it is possible to access the links of every social media citation contributing to the final AAS. To our best knowledge, the longitudinal behavior of Altmetric resources has not yet been studied in any field of medicine or dentistry.