Table 3. Classification of C-shaped root canal in maxillary first and second molars.

Type of C-shaped root canal		CBCT Image representing the type	Description
Type I Fusion of 2 root canals	Subtype A MB-P		mesiobuccal root canal fused with palatal root canal (fusion of 2 roots)
			mesiobuccal root canal fused with palatal root canal (fusion of 3 roots)
	Subtype B DB-P		distobuccal root canal fused with palatal root cana
	Subtype C MB-DB		mesiobuccal root canal fused with distobuccal root canal (fusion of 2 roots)
			mesiobuccal root canal fused with distobuccal root canal (fusion of 3 roots)
Type II Fusion of 3 root canals	Subtype A DB-MB-P		distobuccal root canal fused with mesiobuccal root canal and palatal root canal
	Subtype B MB-P-DB (V shape)		mesiobuccal root canal fused with palatal root canal and distobuccal root canal
Type III Other type of root canal fusion	MP-DP (tooth with 4 root canals)		mesiopalatal root canal fused with distopalatal root canal

In the CBCT image, the arrows indicate the C-shaped root canal of examined teeth, the capital letter indicate each aspect.

M, Mesial; B, Buccal; P, Palatal.