Endodontic management of the maxillary first molar with special root canals: A case report and review of the literature

Table 1 Summary of previous variations reported in root canals in maxillary first molars

Ref.	Yr	No. of roots	No. of canals	Root canals anatomy			Country	Tooth	Sex	Age (yr)	Type of study
				MB	DB	P
Ferguson et al[7]	2005	3	5	3	1	1	United States	L	M	18	Case report
Kottoor et al[14]	2010	3	7	3	2	2	India	R	M	37	Case report
Kottoor et al[10]	2011	3	8	3	3	2	India	L	M	30	Case report
Shin et al[11]	2013	1	1	O-shaped			Korea	L	M	39	Case report, ex vivo study
Badole et al[9]	2014	3	7	3	2	2	India	L	M	28	Case report
Ahmad et al[31]	2014	3	5	3-2, 3-3	1	1	Germany	R	M	28	Case report
Asghari et al[2]	2015	4	4	1	1	2	Iran	R	W	21	Case report
Rodrigues et al[36]	2017	3	7	3	2	2	Brazil	R	W	23	Case report
Schryvers et al[6]	2019	4	4	1	1	2	Belgium	L	M	44	Case report
Liu et al[33]	2019	2	2	1		1	China	L, R	W, W	63, 45	Case report

MB: Mesiobuccal; DB: Distobuccal; L: Left; R: Right; M: Men; W: Women.