Table 1.

Percent of root canal of maxillary second premolars in various studies

Author	Year	No of canals
		No of teeth	One canal at apex (%)	Two canals at apex (%)	Three canals at apex (%)
Pineda and Kuttler[2]	1972	282	81.8	18.2	0
Vertucci[11]	1974	200	75	24	1
Bellizzi and Hartwell[12]	1985	630	40.3	58.6	1.1
Pecora et al.[9]	1992	300	67.3	32.4	0.3
Caliskan et al.[13]	1995	100	72	28	0
Chima[14]	1994	26 females	30	73	0
		20 males	30	70	0
Kartal et al.[11]	1997	300	55	44.4	0.6
Sert and Bayirli[7]	2004	100 females	75	24	1
		100 males	49	48	3
Khurram et al.[15]	2005	57 females	47	53	0
		43 males	37	63	0
Rozylo et al.[16]	2008	56	14.7	85.3	0
Weng et al.[10]	2009	65	27.7	72.3	0
Present study[*]	2010	200	64.1	35.4	0

^*Type XIX (Sert and Bayirli) – 0.5%