The impact of COVID-19 pandemic on teeth grinding in the US and UK

Riccardo Nocini,Camilla Mattiuzzi,Giuseppe Lippi

1Department of Surgery,Dentistry,Paediatrics and Gynaecology-Unit of Otorhinolaryngology,University of Verona,Verona,Italy.

2Service of Clinical Governance,Provincial Agency for Social and Sanitary Services(APSS),Trento,Italy.

3Section of Clinical Biochemistry and School of Medicine,University of Verona,Verona,Italy.

Abstract Background: Preliminary evidence suggests that the burden of stress and anxiety may have considerably increased during the coronavirus disease 2019 (COVID-19) pandemic. Since these two mental health-related factors are important causes of teeth grinding, we carried out an infodemiological analysis to define whether the burden of teeth grinding may have increased as a consequence of COVID-19.Methods: We conducted an electronic search in Google Trends, with the term “teeth grinding”,setting the geographical area to “US” or “UK” and the search period between July 2017 and July 2022. The weekly Google Trends score for “teeth grinding” was downloaded,and the difference in the volume Google searches for “teeth grinding” was compared between the pre-COVID-19 and COVID-19 periods in both countries.Results: The median value of weekly Google Trends score for “teeth grinding” was found to be significantly increased after emergence of the COVID-19 pandemic both in the UK (57 with interquartile range[IQR] 51-64 vs. 48 with IQR 42-53; +19% and P＜0.001) and the US (78 with IQR 73-83 vs. 70 with IQR 66-74; +11% and P＜0.001), compared to the homologous period before.Conclusion: The results of this infodemiological analysis reveal that the volume of Web searches for “teeth grinding” in both the UK and US has considerably increased after emergence of the COVID-19 pandemic, thus probably reflecting an increased burden of this condition in the general population.

Keywords:COVID-19, Pre-COVID-19, Teeth grinding, Google Trends

Background

Teeth grinding, a relatively common condition also frequently referred to as “bruxism”, is a detrimental oral motor activity characterized by repetitive (almost unconscious) contraction of masseter and temporalis muscles, which affects in variable form between 20-90% of the adult population [1,2] and causes overload of stomatognathic structures, thus often leading to unfavourable consequences such as tooth injuries, temporomandibular joint disorders, headache and earache, among others [1-3]. Although the aetiology of this condition is still unclear and perhaps multifactorial,teeth grinding has been very frequently associated with anxiety and stress [1-3]. Since the ongoing coronavirus disease 2019 (COVID-19)pandemic has also been associated with a dramatically increased burden of mental health-related factors in the general population,namely stress and anxiety [4,5], we carried out an infodemiological analysis to define whether the burden of teeth grinding may have increased as a consequence of COVID-19.

Materials and methods

We carried out a digital search in the free website of Google Trends(Google Inc. Mountain View, CA, US), with the search term “teeth grinding”,setting the geographical area alternatively to“US”or“UK”,and with the search period limited to the past 5 years (i.e., between July 2017 and July 2022). The weekly Google Trends score for the term “teeth grinding”, which reflects the popularity of this term, was imported into Microsoft Excel (Microsoft, Redmond, WA, United States) and the outcome of the digital search was separated in two period, i.e., “pre-COVID-19” (ranging between July 2017 and February 2020) and COVID-19 (ranging between March 2020 and July 2022) [6], to reflect the widespread diffusion of COVID-19 (and the relative concerns) among the US and UK populations. The variation of the volume of Google searches for “teeth grinding” in either country was compared between the COVID-19 and pre-COVID-19 periods using the Mann-Whitney test (Analyse-it Software Ltd, Leeds, UK), and with statistical significance set atP＜0.05. The study was conducted in accordance with the Declaration of Helsinki, under the terms of relevant local legislation. This analysis was based on electronic searches in an open and publicly repository(Google Trends), and thus no informed consent or Ethical Committee approvals were required.

Results

The main results of our infodemiological analysis are summarized in figure 1. The median value of weekly Google Trends score for “teeth grinding” was found to be significantly increased after emergence of the COVID-19 pandemic both in the UK (57 with interquartile range[IQR] 51-64 vs. 48 with IQR 42-53; +19% andP＜0.001) and the US(78 with IQR 73-83 vs. 70 with IQR 66-74; +11% andP＜0.001),compared to the homologous period before. Interestingly, the median value of weekly Google Trends score for “teeth grinding” was also found to be higher in the UK compared to the US, both in the pre-COVID-19 (P＜0.001) and COVID-19 (P＜0.001) periods. A similar search in Google Trends carried out with the less popular term“bruxism” generated almost identical data (data not shown).

Figure 1.Weekly Google Trend score for“teeth grinding”in the US and UK during and before the coronavirus disease 2019 pandemic

Discussion

Although we acknowledge that predicting the burden of a particular oral disturbance only using an infodemiological approach may not provide a comprehensive picture of real epidemiology, the result of this infodemiological analysis seemingly reveals that the volume of Web searches for “teeth grinding” in both the UK and US has considerably increased after emergence of the COVID-19 pandemic,thus reliably reflecting an increased burden of this condition in the general population [7]. This interesting finding mirrors and complement earlier data published in other studies. For example, a previous analysis carried out more than 2 years before our analysis by Kardeş et al.[8],revealed that volume of Google searches for the same keyword (i.e., “teeth grinding”) significantly increased in 2020 compared to the period between 2016-2019, displaying a nearly 25%and 17% increase worldwide and in the US, respectively, figures that are closely aligned to those emerged in our longer and more recent analysis. In a separate study, Vlăduțu et al. [9] reported the existence of a significant association between self-evaluated increased stress and bruxism in young students during the COVID-19 pandemic, which then reflects in a major predisposition towards teeth grinding or clenching. Finally, Mirhashemi et al. carried out a meta-analysis of studies which reported the association between oral habits and COVID-19 pandemic in both adolescents and adults [10], concluding that the enhanced level of stress due to the COVID-19 pandemic may have considerably increased detrimental oral habits such as temporomandibular disorders, bruxism and teeth grinding.

Taken together, the data emerged from previous studied combined with the findings of our recent infodemiological analysis shall foster public health concerns, in that the recently increased burden of teeth grinding presumably boosted by the COVID-19 pandemic may frequently trigger tooth damage, tempormandibular and other physical disorders, up to psychosocial impairment [2]. Based on this assumption, we suggest that more efforts shall be made for potentiating dentists and endodontists practices, to face the enhanced burden of endodontic diseases that may derive from the ongoing and apparently unremitting COVID-19 pandemic.