## 3 Results
### General Analysis of Included Studies  
Fifty-two articles were included. The number of participants ranged from 14 to 903. Twenty-nine studies analyzed GP through 2D photographs [14, 15, 17, 20, 21, 25, 26, 31, 32, 33, 37, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 56, 58, 59, 60, 63, 64, 68], 10 studies used dental casts [16, 23, 24, 30, 43, 44, 53, 54, 55, 56, 61] while six studies used both methods of assessment [18, 19, 22, 57, 62, 65]. Six studies performed direct clinical measurements of teeth on patients [35, 36, 38, 39, 66, 67] and one study reported digital impressions, digital casts, and 2D photograph analysis in their research [52] (Table 2). All included studies [14, 15, 16, 23, 30, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68] were categorized according to their geographical location. The majority (\(n=27\)) of studies were carried out in the South Asian region, followed by West Asia (\(n=13\)), Europe (\(n=8\)), Africa (\(n=3\)), North America (\(n=3\)), East Asia (\(n=2\)), Southeast Asia (\(n=2\)), the Middle East (\(n=2\)), and South America (\(n=1\)) (Table 3). \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{3}{*}{**No**} & \multirow{3}{*}{**Author**} & \multirow{3}{*}{**
\begin{tabular}{c} **GP** \\ **Control** \\ **Group** \\ \end{tabular} } & \multirow{3}{*}{**Unit**} & \multicolumn{3}{c}{**Right**} & \multicolumn{3}{c}{**Left**} & \multicolumn{3}{c}{**Right**} & \multicolumn{3}{c}{**Left**} \\ \cline{4-9}  & & & **Central/** & **Lateral/** & **Lateral/** & **Lateral/** & **Lateral/** & **Lateral/** & **Central/** & **Lateral/** \\  & & & **Lateral/** & **Lactic \%** & **Lactic \%** & **Lactic \%** & **Lactic \%** & **Lactic \%** & **Lactic \%** & **Lactic \%** & **Lactic \%** \\ \hline
48. & [PERSON] [64] & 62\% GP &
\begin{tabular}{c} Mean \\ \end{tabular} & NR & NR & NR & NR & 59.00 & 85.00 & 58.00 & 89.00 \\ \cline{2-9}  & & & & & & & & & & \\ \cline{2-9}  & & & & & & & & & & \\ \cline{2-9}  & & & & & & & & & & \\ \hline
49. & \
\begin{tabular}{c} [PERSON] et al. \\ [65] \\ \end{tabular} & 62\% GP &
\begin{tabular}{c} Mean \\ \end{tabular} & NR & NR & NR & NR & 65.00 & 89.00 & 65.00 & 89.00 \\ \cline{2-9}  & & & & & & & & & \\ \cline{2-9}  & & & & & & & & & \\ \hline
50. & \
\begin{tabular}{c} [PERSON] et al. \\ [66] \\ \end{tabular} & 62\% GP &
\begin{tabular}{c} Mean \\ \end{tabular} & NR & NR & NR & & NR & 24.00 & 14.50 & 24.00 & 14.50 \\ \cline{2-9}  & & & & & & & & & \\ \cline{2-9}  & & & & & & & & & \\ \hline
51. & [PERSON] [67] & 62\% GP &
\begin{tabular}{c} Mean \\ \end{tabular} & 4.50 & 10.70 & 4.50 & 10.70 & 49.60 & 67.70 & 49.60 & 67.70 \\ \cline{2-9}  & & & & & & & & & \\ \cline{2-9}  & & & & & & & & & \\ \hline
52. & \
\begin{tabular}{c} [PERSON] \\ [68] \\ \end{tabular} & 62\% GP &
\begin{tabular}{c} Mean \\ \end{tabular} & 2.40 & 4.90 & 2.40 & 4.90 & 59.00 & 59.00 & 59.00 & 59.00 \\ \cline{2-9}  & & & & & & & & & \\ \cline{2-9}  & & & & & & & & & \\ \hline \hline \end{tabular}  
0: Indicates no values for 62% golden proportion or local proportion given in included articles, GP: golden proportion, b Local proportion: value other than 62% found in studied population, Sd: standard deviation, GP: golden proportion.  
\end{table} 
Table 1: _Cont._  
0: Indicates no values for 62% golden proportion or local proportion given in included articles, GP: golden proportion, b Local proportion: value other than 62% found in studied population, Sd: standard deviation, GP: golden proportion. \end{table}
Table 2: Study characteristics of included articles (\(n=52\)). \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & \multicolumn{3}{c}{**Research Groups**} & \multicolumn{3}{c}{**Sample Size**} & \multicolumn{1}{c}{**Conclusion/Outcome**} \\ \cline{3-8}
**Authors** & **Study Design** & **Study** & **Control** & **Assessment** & & **C** & **S** & \\ \cline{3-8}  & & & & & & & **C** & **S** & \\ \hline [PERSON] [19] &