Using Cone-Beam Computed Tomography to Determine the Prevalence of the Second Mesiobuccal Canal in Maxillary First Molar Teeth in a Sample of an Iraqi Population

Figures & data

Table 1 Previous Studies on Evaluation of the Prevalence of MB2 Canals in Different Populations

Authors	Year	Sample Size	Population	Study Type	Mb2 Frequency
Alrahabi and Zafar^Citation6	2015	100	Saudi	ex vivo	70.65%
Aktan et al^Citation7	2016	468	Turkish	in vivo	63.25%
Yu-hua Lin et al^Citation8	2017	196	Taiwanese	in vivo	56%
Ghobashi et al^Citation9	2017	675	Egyptian	in vivo	74.5%
Khademi et al^Citation10	2017	389	Iranian	in vivo	70.2%
Hiebert et al^Citation11	2017	100	American	ex vivo	78%
Shetty et al^Citation2	2017	66	Indian	in vivo	86.3%
Zhang et al^Citation12	2017	1008	Chinese	in vivo	85.4%
Martins et al^Citation13	2018	567 Europeans 239 Asians	Europeans Chinese	in vivo	73.1%Europeans 58.4% Asians
Ratanajirasut et al^Citation14	2018	476	Thai	in vivo	63.6%
Fernandes et al^Citation15	2019	200	South African	in vivo	89.5%
Rouhani et al^Citation16	2019	125	Iranian	ex vivo	53.6%
Tzeng et al^Citation17	2020	846	Taiwanese	in vivo	79.2%

Figure 1 Diagrammatic representations of Vertucci’s classification for root canal morphology.

Notes: Reproduced with permission of Guillermo Concha from Torres et al Characterization of mandibular molar root and canal morphology using cone-beam computed tomography and its variability in Belgian and Chilean population samples. Imaging science in dentistry. 2015;45(2):95–101.²⁰ Under Copyright © 2015 by Korean Academy of Oral and Maxillofacial Radiology; Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/).

Table 2 Age and Sex Distribution of the Sample

	Female (N= 212)	Male (N=92)	P value*
Age in years (mean ± SD)	29.3 ± 8.9	31.9 ± 8.5	0.07
Age (median)	26	31

Note: *Mann–Whitney’s test.

Table 3 Types of Canals on Right and Left Sides

Canal Type	Right		Left		Total		Kendal Tau R	P value
	Frequency	Percent	Frequency	Percent	Frequency	Percent
Type I (1)	63	18.58	57	18.04	120	18.32	0.409	0.001
Type II (2–1)	145	42.77	147	46.52	292	44.58
Type III (1-2-1)	12	3.54	3	0.95	15	2.29
Type IV (2)	106	31.27	99	31.33	205	31.30
Type V (1–2)	5	1.47	10	3.16	15	2.29
Type VI (2-1-2)	4	1.18	0	0.00	4	0.61
Type VII (1-2-1-2)	4	1.18	0	0.00	4	0.61
Total	339	100.00	316	100.00	655	100.00

Figure 2 Graphical representation of canal types on the right and left sides.

Figure 3 Radiographic representation of canal types I, II, IV, and V in axial and coronal sections on CBCT images (arrows representing position of mesiobuccal canals in MFMs) (Axial 1: Coronal part of the mesiobuccal root in axial section. Axial 2: Middle part of the mesiobuccal root in axial section. Axial 3: Apical part of the mesiobuccal root in axial section). Coronal: coronal section. (A) Type I in axial and coronal sections. (B) Type II in axial and coronal sections. (C) Type IV in axial and coronal sections. (D) Type V in axial and coronal sections.

Table 4 Distribution of Canal Type According to Gender

		Right			P value*	Left			P value*
		Male	Female	Total		Male	Female	Total
Type I	Frequency	19	44	63	0.002 significant	13	44	57	<0.001 Highly significant
	Percent	14.5%	21.2%	18.6%		9.8%	23.9%	18.0%
Type II	Frequency	77	68	145		71	76	147
	Percent	58.8%	32.7%	42.8%		53.8%	41.3%	46.5%
Type III	Frequency	0	12	12		3	0	3
	Percent	0.0%	5.8%	3.5%		2.3%	0.0%	0.9%
Type IV	Frequency	34	72	106		43	56	99
	Percent	26.0%	34.6%	31.3%		32.6%	30.4%	31.3%
Type V	Frequency	1	4	5		2	8	10
	Percent	0.8%	1.9%	1.5%		1.5%	4.3%	3.2%
Type VI	Frequency	0	4	4		0	0	0
	Percent	0.0%	1.9%	1.2%		0.0%	0.0%	0.0%
Type VII	Frequency	0	4	4		0	0	0
	Percent	0.0%	1.9%	1.2%		0.0%	0.0%	0.0%
Total	Frequency	131	208	339		132	184	316
	Percent	100.0%	100.0%	100.0%		100.0%	100.0%	100.0%

Note: *Chi-squared test.

Table 5 Distribution of Types of Canal on the RIGHT Side According to the Age Groups

Type		Age				Total	P-value*
		18–26 Years	27–36 Years	37–46 Years	47–56 Years
Type I	Frequency	29	25	6	3	63	0.76 Non-significant
	Percent	17.9%	22.3%	12.0%	20.0%	18.6%
Type II	Frequency	64	47	24	10	145
	Percent	39.5%	42.0%	48.0%	66.7%	42.8%
Type III	Frequency	5	5	2	0	12
	Percent	3.1%	4.5%	4.0%	0.0%	3.5%
Type IV	Frequency	55	33	16	2	106
	Percent	34.0%	29.5%	32.0%	13.3%	31.3%
Type V	Frequency	3	1	1	0	5
	Percent	1.9%	0.9%	2.0%	0.0%	1.5%
Type VI	Frequency	4	0	0	0	4
	Percent	2.5%	0.0%	0.0%	0.0%	1.2%
Type VII	Frequency	2	1	1	0	4
	Percent	1.2%	0.9%	2.0%	0.0%	1.2%
Total	Frequency	162	112	50	15	339
	Percent	100.0%	100.0%	100.0%	100.0%	100.0%

Note: *Chi-squared test.

Table 6 Distribution of Types of Canal on the LEFT Side According to the Age Groups

		18–26 Years	27–36 Years	37–46	47–56	Total	P-value*
Type I	Frequency	27	19	7	4	57	0.521 Non-significant
	Percent	18.60%	18.10%	14.00%	25.00%	18.00%
Type II	Frequency	58	56	25	8	147
	Percent	40.00%	53.30%	50.00%	50.00%	46.50%
Type III	Frequency	2	0	1	0	3
	Percent	1.40%	0.00%	2.00%	0.00%	0.90%
Type IV	Frequency	52	29	14	4	99
	Percent	35.90%	27.60%	28.00%	25.00%	31.30%
Type V	Frequency	6	1	3	0	10
	Percent	4.10%	1.00%	6.00%	0.00%	3.20%
Total	Frequency	145	105	50	16	316
	Percent	100.00%	100.00%	100.00%	100.00%	100.00%

Note: *Chi-squared test.

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