On the occasion of Wolrd Smile Day, it is interesting to think about the relevance of smiling - and, more generally, of the manifestation of emotional states - in interpersonal relationships, especially in these times that see part of the emotional expressions covered by masks. Says Dr. Sarah Songhorian, researcher in Moral Philosophy: "Emotions are manifested primarily by the face: the so-called primary emotions - including the joy manifested by smiling - not only have a facial display, but many argue that they are universal, or at least pan-cultural".
Grasp, perceive and understand emotive manifestations
The human ability to grasp, perceive and understand the emotive manifestations of others is an essential element of our non-verbal social communication - if I smile I expect my interlocutor to smile, I expect sharing, an automatic tuning of our affective states.
It is also on the basis of this attunement, of the empathic response from the other, that more significant interpersonal relationships can be structured - certainly this minimal level of sharing is not enough to become friends or to trust others, but it contributes considerably.
If the most significant interpersonal relationships are promoted by sharing the emotions that we see expressed in the faces of others, one might wonder - and several have done so since the Covid-19 pandemic began - how much covering part of the face with a mask may have a deleterious effect in our understanding and subsequent sharing of the emotions of others [1-4].
Although the masks do not cover the entire face and let us catch a smile - and other emotions - from the dynamics of the eyes, they certainly make the task more difficult: the mouth, in fact, is the central element of the manifestation of many emotions. The recognition of emotions was then greatly deteriorated [1-2].
Similarly, our ability to trust others and recognize them on subsequent occasions is made more difficult by the use of masks. This being the case, it seems inevitable that masks have an effect on our interpersonal relationships. This obviously does not mean to argue that they are not essential to protect our and others' health, but only to make us aware of the effects they can have. Awareness of a limit is the first step to learning and improving. We will then have to learn, as long as the masks are needed, to look for smiles in the eyes rather than in the mouths.
Take care of your smile
Even behind the mask, it is important to take care of your mouth. Explains Dr. Elisabetta Polizzi, Coordinator of the Degree Course in Dental Hygiene, Director of the UniSR Oral Hygiene and Prevention Center and Chief Operation Manager Smart Dental Clinic GSD: "The prevention of caries and plaque accumulations is the basis for controlling mouth health and consequently improve the quality of life; for this reason, in addition to oral hygiene sessions at the dentist/hygienist at least once a year, they must also be taken care of regularly at home".
Here are some useful tips for a healthy smile.
The plaque-disclosing tablets
The accumulation of plaque is not visible to the naked eye, except in cases where the deposit is significant. On the market there are plaque-disclosing tablets that color the teeth, indicating the most affected points, in order to highlight where it is necessary to brush more carefully.
Toothbrush, toothpaste and interdental tools
To prevent caries disease, in addition to brushing the teeth several times a day, it is advisable to complete with interdental tools, whether they are dental floss or brushes. Increased sensitivity to contact with cold foods and liquids is a reaction caused by the loss of enamel (the lining of the teeth) or by a retraction of the gum. In these cases, the use of a toothbrush with soft filaments and a toothpaste for sensitive teeth enriched with fluoride is recommended.
Beware of food and drink
We carefully select the foods to be consumed. It is advisable to limit the intake of foods rich in complex sugars (for example refined carbohydrates such as cereals, candies, potatoes) or sour fruit (such as citrus fruits, pineapple, strawberries and red fruits). Drink fizzy drinks, and soft drinks, and energizing cola in moderation since they contain carbonate and solubilize the prisms of the enamel. On the other hand, foods rich in vitamin D (contained in salmon, mackerel and fatty fish), foods that are a source of calcium (such as milk, cheese, yogurt), green leafy vegetables (spinach, kale and sesame seeds). It is good to take a lot of fibers which, contained in bananas, apples and dried fruit, stimulate the production of saliva, useful for maintaining the physiology of cleansing the mouth.
Tea and coffee
Excessive consumption of tea and coffee and of all foods that contain chromogens (pigmenting substances) can cause unsightly stains on the teeth, which can be eliminated with a professional oral hygiene session.
Stains on the teeth are also due to smoking, which must be limited: in addition to the aesthetic damage caused by nicotine, smoking reduces the oxygenation of tissues, favoring the survival of aggressive bacteria, responsible for the formation of plaque and tartar.
 Tanaka K., Miyake Y., Sasaki S., Intake of dairy products and the prevalence of dental caries in young children, J Dent, Jul;38(7):579-83 (2010). doi: 10.1016/j.jdent.2010.04.009
 Martin-Cabezas R.,Davideau J.L., Tenenbaum H., Huck O., Clinical efficacy of probiotics as an adjunctive therapy to non-surgical periodontal treatment of chronic periodontis: a systematic review and meta-analysis, J Clin Periodontal, Jun; 43(6):520-30) 2016). doi: 10.1111/jcpe.12545
 Moreno-Arribas MV et al., Inhibition of oral pathogens adhesion to human gingival fibroblasts by wine polyphenols alone and in combination with an oral probiotic, Journal of Agricultural and Food Chemistry, Mar 7;66(9):2071-2082 (2018). doi: 10.1021/acs.jafc.7b05466Similarly, our ability to trust others and recognize them on subsequent occasions is made more difficult by the use of masks. This being the case, it seems inevitable that masks have an effect on our interpersonal relationships. This obviously does not mean to argue that they are not essential to protect our health and that of others, but only to make us aware of the effects they can have. Awareness of a limit is the first step to learning and improving. We will then have to learn, as long as the masks are needed, to look for smiles in the eyes rather than in the mouths.