Table 1.

The formulas used to calculate the development of the arches.

Methods	Equations
Pont index	Sum of incisors (SI) = sum of mesio-distal width of the maxillary incisors
	Interpremolar arch widths $=\frac{\mathrm{sum} \mathrm{of} \mathrm{the} \mathrm{widths} \mathrm{of} \mathrm{the} \mathrm{maxillary} \mathrm{incisors}\times 100}{80}$
	Intermolar arch widths $=\frac{\mathrm{sum} \mathrm{of} \mathrm{the} \mathrm{widths} \mathrm{of} \mathrm{the} \mathrm{maxillary} \mathrm{incisors}\times 100}{64}$
Linder–Harth index	Interpremolar arch widths $=\frac{\mathrm{sum} \mathrm{of} \mathrm{the} \mathrm{widths} \mathrm{of} \mathrm{the} \mathrm{maxillary} \mathrm{incisors}\times 100}{85}$
	Intermolar arch widths $=\frac{\mathrm{sum} \mathrm{of} \mathrm{the} \mathrm{widths} \mathrm{of} \mathrm{the} \mathrm{maxillary} \mathrm{incisors}\times 100}{65}$
Bolton’s analysis	Anterior ratio $=\frac{\mathrm{sum} \mathrm{of} \mathrm{the} \mathrm{widths} \mathrm{of} \mathrm{the} 6 \mathrm{mandibular} \mathrm{anterior} \mathrm{teeth}}{\mathrm{sum} \mathrm{of} \mathrm{the} \mathrm{widths} \mathrm{of} \mathrm{the} 6 \mathrm{maxillary} \mathrm{anterior} \mathrm{teeth}}\times 100$
	Overall ratio $=\frac{\mathrm{sum} \mathrm{of} \mathrm{the} \mathrm{widths} \mathrm{of} \mathrm{the} 12 \mathrm{mandibular} \mathrm{teeth}}{\mathrm{sum} \mathrm{of} \mathrm{the} \mathrm{widths} \mathrm{of} \mathrm{the} 12 \mathrm{maxillary} \mathrm{teeth}}\times 100$