Mandibular left first premolar with three roots and three canals: A case report

Table 1 Incidence of Vertucci type-VIII variations in mandibular first premolars by region

Ref.	Region	Country	Sample size	Type-VIII variation (n)	Incidence	Roots/tooth (n)
Wu et al[22], 2020	East Asia	China	1280	6	0.47%	1
Thanaruengrong et al[23], 2021	South Asia	Thailand	621	0	0	/
Algarni et al[24], 2021	Southwest Asia	Saudi Arabia	216	0	0	/
Sierra-Cristancho et al[25], 2021	South America	Chile	186	0	0	/
Reda et al[26], 2022	Europe	Italy	380	2	0.53%	/
Buchanan et al[27], 2022	Africa	South Africa	386	1	0.26%	3