## 3 Results  
The total sample consisted of 121 pre-orthodontic patients, comprising 43 males and 78 females which a median age of 17.04 (IQR = 13.7-22.1). Table 1 shows a description of the sample regarding age, sex, gingival biotype, and facial typology. Two-dimensional and 3D cephalometric data are reported in Table 2, and all were normally distributed. Figure 3: **(a–c)** Points, planes, and angles for the assessment of facial typology with cephalometry and facial scanner. **(a)** ‘Sellion’ (S, the center of the sella turcica), ‘Nasion’ (N, the external point of the junction between the nasal and frontal bones), ‘Gonion’ (Go, the most inferior posterior point of the mandibular angle), ‘Gnathion’ (Gn, the point of the mandibular symbiosis on the facial axis) ‘Menton’ (Me, the most inferior point of the mandibular symphysis), ‘Condylion’ (Co, the highest and most posterior point on the contour of the mandibular conde); **(b)** SN plane, GoGn plane, and CoGoMe angle; **(c)** N (‘Soft Tissue Nasion’, the midpoint on the soft tissue contour of the base of the nasal root at the level of the frontonasal suture), SN (‘SubNasion’, the midpoint on the nasolabial soft tissue contour between the columella crest and the upper lip), and Me (‘Soft Tissue Menton’, the most inferior midpoint on the soft tissue contour of the chin). NMe indicates total facial height and SNMe indicates inferior facial height. The sample was divided into three groups according to SN'GoGn, and there were 33 (27.27%) brachyfacial patients, 59 (48.76%) mesofacial patients, and 29 (23.97%) dolichofacial patients, as shown in Table 1.  
Regarding gingival biotype, most patients presented a thick gingival biotype (upper anterior teeth (UGB) 86.78%; lower anterior teeth (LGB) 52.07%), as seen in Table 1.  
The Chi-squared test showed that there was no statistically significant association between SN'GoGn and gingival biotype (UGB \(p\) = 0.83; LGB \(p\) = 0.75; and gingival biotype \(p\) = 0.77, Table 3). Similarly, the logistic regression analysis showed that CoGoMe' was not associated with any variables of gingival biotype (UGB, \(p\) = 0.340; LGB, \(p\) = 0.065). Finally, logistic regression analysis showed a statistically significant association of SNMe/NMe with the UGB (odds ratio = 0.843; 95% CI 0.719-0.989; \(p\) = 0.036) and of SNMe/NMe with LGB (odds ratio = 0.904; 95% CI 0.818-1.000; \(p\) = 0.049), showing that when the ratio of SNMe/NMe decreases, there is a minor risk of finding a thin biotype (Table 4). \begin{table}
\begin{tabular}{l c c} \hline \hline
**Variables** & **N** & **Median (IQR)** \\ \hline Age & 121 & 17.04 (13.7–22.1) \\ \hline  & Frequency & Percentage (\%) \\ \hline Gender & 43 & 35.54 \\ \multicolumn{1}{c}{Female} & 78 & 63.64 \\ \hline Upper Gingival Biotype & & \\ Thick & 105 & 86.78 \\ Thin & 16 & 13.22 \\ \hline Lower Gingival Biotype & & \\ Thick & 63 & 52.07 \\ Thin & 58 & 47.93 \\ \hline Facial Typology SN’GoGn & & \\ \multicolumn{1}{c}{Brachyfacial} & 33 & 27.27 \\ \multicolumn{1}{c}{Mesofacial} & 59 & 48.76 \\ \multicolumn{1}{c}{Dolichofacial} & 29 & 23.97 \\ \hline \hline \end{tabular} Data are presented as median and interquartile range (IQR) or frequencies and percentages.  
\end{table} 
Table 1: Characteristics of study subjects according to age, gender, gingival biotype, and facial typology.