## 2 Materials and Methods  
A cross-sectional design was used to realize this observational study, recording the prevalence of dental caries, oral mucosa lesions, and gingival health status in a migrant population coming from middle- and low-income countries and resident in Italy. Our research included 200 migrant subjects, aged between 3 and 37, who visited the dental department of the Policlinico Tor Vergata (Rome, Italy) in the period from 1 September 2021 to 31 March 2022. This study was approved by the Fondazione Policlinico Tor Vergata (Rome, Italy) ethical committee (approval number N. 0001919/2020 del 29/01/2020).  
Inclusion criteria were as follows: (a) subjects under the age of 40 years; (b) patients identified as migrants; (c) persons whose country of origin was identified as middle- or low-income country; (d) participants aged 18 years and older had to be born in middle- or low-income countries; (e) parents of patients under the age of 18 had to be born in middle- or low-income countries; (f) migrants resident in Italy. Persons aged 40 years and older, migrants identified as asylum seekers or refugees, non-migrant subjects, or migrants coming from high-income countries were excluded from our study.  
The selected sample included 110 female and 90 male subjects aged between 3 and 37 (median age 9.39 years old \(\pm\) 6.49). This research selected 188 children, of whom 30 were born in middle- and low-income countries, and 158 were born in Italy but had both parents whose country of birth was a middle- or low-income country. The subjects selected for our study came from (Table 1):  
Africa (\(n=62\)): Egypt (\(n=42\)), Morocco (\(n=10\)), Tunisia (\(n=4\)), Senegal (\(n=3\)), Algeria (\(n=1\)), Cameroon (\(n=1\)), and Mauritius (\(n=1\));  
Central and South America (\(n=58\)): Peru (\(n=36\)), Ecuador (\(n=13\)), El Salvador (\(n=7\)), Venezuela (\(n=1\)), and Bolivia (\(n=1\));  
Europe (\(n=45\)): Romania (\(n=13\)), Albania (\(n=13\)), Ukraine (\(n=6\)), Moldavia (\(n=5\)), Kosovo (\(n=2\)), Montenegro (\(n=3\)), Bosnia and Herzegovina (\(n=1\)), and Turkey (\(n=2\));  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Country**} & **Total** & \multicolumn{2}{c}{**Parents’ Country of**} & **Child’s Country of Birth** & **Adult Subject’s Country of Birth** \\  & N. & **Birth** & **(Aged between 3 and 17)** & **(Aged between 18 and 37)** \\  & & N. & & \(N\). & \(N\). \\ \hline Egypt & 42 & 28 & **11** & 3 \\ Peru & 36 & 28 & 7 & 1 \\ Ecuador & 13 & 12 & / & 1 \\ The Philippines & 12 & 11 & / & 1 \\ Tunisia & 4 & 2 & **1** & 1 \\ Morocco & 10 & 9 & / & 1 \\ Montenegro & 3 & 3 & / & / \\ Bangladesh & 5 & 4 & 1 & / \\ Pakistan & 1 & / & 1 & / \\ Algeria & 1 & 1 & / & / \\ Romania & 13 & 10 & 1 & 2 \\ Sri Lanka & 6 & 5 & 1 & / \\ Nepal & 1 & 1 & / & / \\ Moldavia & 5 & 4 & 1 & / \\ Albania & 13 & 11 & / & 2 \\ Turkey & 2 & 2 & / & / \\ Kosovo & 2 & 2 & / & / \\ Senegal & 3 & 3 & / & / \\ Bolivia & 1 & 1 & / & / \\ Venezuela & 1 & / & / & 1 \\ Bosnia and Herzegovina & 1 & / & 1 & / \\ India & 3 & 3 & / & / \\ El Salvador & 7 & 4 & 3 & / \\ China & 6 & 6 & / & / \\ Ukraine & 6 & 4 & 2 & / \\ Cameroon & 1 & 1 & / & / \\ Mauritius & 1 & 1 & / & / \\ Saudi Arabia & 1 & 1 & / & / \\ Total & 200 & 158 & 30 & 12 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Country of origin of included patients.  
Asia (\(n=35\)): China (\(n=6\)), India (\(n=3\)), the Philippines (\(n=12\)), Pakistan (\(n=1\)), Sri Lanka (\(n=6\)), Bangladesh (\(n=5\)), Nepal (\(n=1\)), and Saudi Arabia (\(n=1\)).