International Journal of Dentistry

Review Article

Three-Rooted Permanent Mandibular First Molars: A Meta-Analysis of Prevalence

Table 1

Population, country, number of patients, number of teeth, geographic location, condition, setting, and study design of the included studies.


No.	Study name	Population	Country	Number of patients	Number of teeth (PMFM)	Geographic location	Condition termed as	CBCT (setting)	Study design
1	Abarca et al. [30]	Chilean population	Chile	289	510	America	“Number of roots”	Gendex® GXCB-500, 120 kVp	Cross-sectional, descriptive, and retrospective
								5 mA
								0.2 mm voxel size

2	Al-Alawi et al. [31]	Saudi Arabian population	Saudi Arabia	450	741	West Asia	“Radix Molaris”	(i) ProMax 3D Max (90 kVp, 10 mA)	Cross-sectional, descriptive, and retrospective
								(ii) Galileos Comfort (85 kVp, 7 mA, and voxel size 0.2–0.4 mm)
								(iii) CS9300 (90 kVp, 10–15 mA, and voxel size 0.9 mm)
3	Albarzanji and Jamil [32]	Iraqi population	Iraq	100	141	West Asia	“Extra distal root”	NewTom VGi 9000	Cross-sectional, descriptive, and retrospective
								110 kVp
								19 mA
								015 mm voxel size
								FOV 12 × 7.5 cm
4	Alenezi et al. (τ) [33]	Saudi Arabian population	Saudi Arabia	400	400	West Asia	“Three-rooted”	ProMax 3D Max	Cross-sectional, descriptive, and retrospective
								Voxel size 0.2–0.6 mm
5	Atsushi and Shotaro (τ) [34]	Japanese population	Japan	141	279	East Asia	“Distolingual root”	ProMax 3D	Cross-sectional, descriptive, and retrospective
								84 kVp
								12 mA
								FOV 0.16 × 0.16 × 0.16 mm
6	Bagherpour et al. (τ) [35]	Iranian population	Iran	100	100	West Asia	“Three roots”	ProMax 3D Planmeca	Cross-sectional, descriptive, and retrospective
								Not reported detail setting
7	Caputo et al. [36]	Brazilian population	Brazil	198	342	America	“Supernumerary root”	Gendex CB 500	Cross-sectional, descriptive, and retrospective
								Voxel size 0.2 mm
								FOV 8 × 14 cm
8	Celikten et al. [37]	Turkish Cypriot population	Cypriot	272	384	Europe	“Three roots”	NewTom 3G, FOV 9, 110 kVp, 0.3 mm voxel size	Cross-sectional, descriptive, and retrospective
9	Chakradhar et al. [38]	Nepalese population	Nepal	571	1142	South Asia	“Radix Entomolaris”	Rainbow TM CT	Cross-sectional, analytical, and prospective
								100 kVp
								12 mA
								16 × 18 cm FOV
								Voxel size 300 μm
10	Choi et al. [39]	South Korean population	South Korea	264	528	East Asia	“Distolingual root”	Alphard Vega scanners	Cross-sectional, descriptive, and retrospective
								FOV 512 × 512 mm
								80 kVp
								5 mA
								Voxel size of 0.39 mm
11	Dastgerdi et al. [40]	Iranian population	Iran	156	312	West Asia	“Distolingual root”	NewTom	Cross-sectional, descriptive, and retrospective
								FOV 8 × 5 cm
								mA 12
								kVp 85
								Voxel size 0.3 mm
12	Demirbuga et al. [41]	Turkish population from Cappadocia	Turkey	605	823	Europe	“Third root”	NewTom 5G	Cross-sectional, descriptive, and retrospective
								Not reported detail setting
13	Deng et al. [42]	Malaysian population	Malaysia	301	301	Southeast Asia	“Number of roots”	3D Planmeca ProMax	Cross-sectional, descriptive, and retrospective
								FOV 80 × 80 mm
								90 kVp
								10 mA
								Voxel size 0.32 mm
14	Duman et al. [6]	Turkish population	Turkey	850	1318	Europe	“Radix Entomolaris”	NewTom 5G	Cross-sectional, descriptive, and retrospective
								Voxel size 0.125 mm
15	Estrela et al. [43]	Brazilian population	Brazil	618	100	America	“Number of roots”	PreXion 3D	Cross-sectional, descriptive, and retrospective
								FOV 56.00 mm
								90 kVp
								4 mA
								Voxel size of 0.1 mm
16	Felsypremila et al. [44]	Indian subpopulation	India	246	299	South Asia	“Radix Entomolaris” and “Radix Paramolaris”	Kodak 9500 3D	Cross-sectional, descriptive, and retrospective
								FOV 18 × 20 mm
								60–90 kVp
								2–15 mA
17	Garg et al. ($) [45]	Indian population	India	250	500	South Asia	“Distolingual root”	SCT Samatum Balance	Cross-sectional, descriptive, and retrospective
								130 kVp
								90–135 mA
18	Guo et al. [46]	American population	United States	248	496	America	“Distolingual root”	Sirona dental system	Cross-sectional, descriptive, and retrospective
								Voxel size 0.3 mm³
								FOV 15 × 15 × 15 cm³
								85 kVp
								5–7 mA
19	Hai-feng et al. (τ) [47]	Chinese population	China	656	1312	East Asia	“Extra distal root”	Planmeca Romexis	Cross-sectional, descriptive, and retrospective
								90 kVp
								14 mA
								0.2 mm voxel size
								FOV 40 × 40 mm
20	Hiran-us et al. [48]	Thailand population	Thailand	248	256	Southeast Asia	“Three-rooted”	3D Accuitomo	Cross-sectional, descriptive, and retrospective
								FOV 4 × 4 cm/17 × 12 cm
								90 kVp
								5.8 mA
								Voxel size of 0.08–0.25 mm³
21	Hosseini et al. [49]	Iranian population	Iran	113	200	West Asia	“Radix Entomolaris”	NewTom 5G	Cross-sectional, descriptive, and retrospective
								110 kVp
								10 mA
								75 μm voxel size
22	Huang et al. [50]	Taiwanese population	Taiwan	151	237	East Asia	“Three roots”	i-CAT	Cross-sectional, descriptive, and retrospective
								120 kVp
								5 mA
23	Jamshidi et al. [51]	Iranian population	Iran	500	129	West Asia	“Three roots”	ProMax 3D	Cross-sectional, descriptive, and analytic
								84 kVp
								10 mA
24	Jang et al. [52]	South Korean population	South Korea	472	780	East Asia	“Three-rooted” and “distolingual root”	Implagraphy	Cross-sectional and descriptive
								Voxel size of 200 μm
								FOV 144 × 121
25	Jang et al. [53]	South Korean population	South Korea	451	902	East Asia	“Distolingual root”	Dinnova system	Cross-sectional, analytic, and retrospective
								80 kVp
								9.0 mA
								FOV 10 × 10 cm
								Voxel size of 0.167 mm³
26	Jayasinghe and Li [54]	Hong Kong Chinese population	Hong Kong	117	203	East Asia	“Distolingual root”	Spiral CT	Cross-sectional, descriptive, and retrospective
								CT HiSpeed
								150 mA
								512 × 512 pixel
27	Kantilieraki et al. [3]	Greek population	Greek	592	478	Europe	“Radix Entomolaris” and “Radix Paramolaris”	NewTom VGi Evo	Cross-sectional, descriptive, and retrospective
								110 kVp
								3 mA
								Scanora® 3D
								90 kVp
								13 mA
								Voxel 0.1 × 0.1 ×0.1 mm³
28	Kaya-Buyukbayram et al. [55]	Turkish population	Turkey	177	242	Europe	“Radix Entomolaris” and “Radix Paramolaris”	3D Accuitomo 170	Cross-sectional, descriptive, and retrospective
								90 kVp
								5 mA
								250 μm voxel size
								FOV 140 × 100
29	Kim and Yang [56]	South Korean population	South Korea	1400	2800	East Asia	“Distolingual root”	i-CAT	Cross-sectional, descriptive, and retrospective
								129 kVp
								47.74 mA
30	Kim et al. [57]	South Korean population	South Korea	150	300	East Asia	“Distolingual root”	Master 3DS	Cross-sectional, analytical, and retrospective
								90 kVp
								3–7 mA
								Voxel size 0.2–0.4 mm
31	Kim et al. [58]	South Korean population	South Korea	976	1952	East Asia	“Extra distal root”	Dinnova system	Cross-sectional, descriptive, and retrospective
								80 kVp
								9.0 mA
								FOV 10 cm
								Voxel size 0.167 mm³
32	Kim et al. [12]	South Korean population	South Korea	979	1958	East Asia	“2 distal roots”	Dinnova system	Cross-sectional, descriptive, analytical, and retrospective
								80 kVp
								9.0 mA
								FOV 10 cm
								Voxel size 0.167 mm³
33	Kim et al. [59]	South Korean population	South Korea	432	864	East Asia	“Distolingual root”	CB Mercury	Cross-sectional, descriptive, analytical, and retrospective
								120 kVp
								15 mA
								FOV 10 cm
								Voxel size 0.2 mm
34	Martins et al. [60]	Portugal’s population	Portugal	646	450	Europe	“Number of roots”	3D Planmeca ProMax	Cross-sectional, descriptive, and retrospective
								Large FOV
								80 kVp
								15 mA
								Voxel size 0.02 mm
35	Martins et al. [61]	Portugal’s population and Chinese population	Portugal and China	670 (Portugal)	466 (Portugal)	Europe and East Asia	“Number of roots” and “Radix Entomolaris”	3D Planmeca ProMax	Cross-sectional, analytical, and retrospective
								Kodak 9500
				120 (Chinese)	220 (Chinese)			Full arch FOV
								Voxel size 0.02 mm
36	Mashyakhy et al. [62]	Saudi Arabian population	Saudi Arabia	208	274	West Asia	“Three roots”	3D Accuitomo 170	Cross-sectional, analytical, and retrospective
								FOV 170 × 140 mm
								90 kVp
								5.8 mA
								Voxel size 0.25 mm
37	Mashyakhy et al. [63]	Indian population	India	150	255	South Asia	“Three roots”	3D Accuitomo 170	Cross-sectional, analytical, and retrospective
								FOV 170 × 140 mm
								90 kVp
								5–8 mA
								Voxel size 0.25 mm (Saudi Arabia)
								Kodak 9500 3D
								FOV 18 × 20 cm
								60–90 kVp
								2–15 mA
38	Miloglu et al. [64]	Turkish population	Turkey	307	533	Europe	“Extra distolingual root”	NewTom FP QR-DVT	Cross-sectional, descriptive, and retrospective
								110 kVp
								15 mA
39	Monsarrat et al. [65]	France population	France	102	130	Europe	“3 roots”	CS 9500 3D	Cross-sectional, analytical, and retrospective
								90 kVp
								10 mA
								Voxel size 200 μm
								FOV 90 × 150 mm
40	Nazeer and Khan [66]	Pakistani population	Pakistan	78	142	South Asia	“Two distal roots”	Sirona dental system	Cross-sectional, descriptive, and retrospective
								85 kVp
								7 mA
41	Ngeow et al. [67]	Malaysian population	Malaysia	61	115	Southeast Asia	“3-rooted”	i-CAT	Cross-sectional, descriptive, and retrospective
								120 kVp
								3–7 mA
								0.3 mm voxel size
								FOV 60 × 13 cm
42	Ni et al. [68]	Chinese population	China	646	900	East Asia	“Distolingual root”	J. Morita	Cross-sectional, descriptive, and retrospective
								80 kVp
								5 mA
								FOV 8 × 8 cm
43	Nur et al. [69]	Turkish population	Turkey	850	966	Europe	“Number of roots”	I-CAT Vision TM	Cross-sectional, descriptive, and retrospective
								120 kVp
								18.54 mA
								0.3 mm voxel size
44	Pan et al. [70]	Malaysian population	Malaysia	208	370	Southeast Asia	“Radix Entomolaris”	KaVo 3D eXam	Cross-sectional and descriptive
								120 kVp
								5 mA
								Voxel size 0.25
45	Park et al. [71]	South Korean population	South Korea	430	726	East Asia	“DL root”	CBCT	Cross-sectional, descriptive, and retrospective
								Not reported detail setting
46	Patil et al. [72]	Saudi Arabian population	Saudi Arabia	428	Tooth-level data was not reported	Western Asia	“Three-rooted”	Scanora 3D	Cross-sectional, descriptive, and retrospective
								6 mA
								89 kVp
47	Perez-Heredia et al. [73]	Spanish population	Spain	112	121	Europe	“Third root”	9300 3D CBCT unit	Cross-sectional, descriptive, and retrospective
								90 kVp
								4 mA
								FOV 10 × 10 cm
								Voxel size 0.18
48	Pham and Le [74]	Vietnamese population	Vietnam	166	332	Southeast Asia	“Distolingual root”	Pica 330 Trio	Cross-sectional, descriptive, and retrospective
								FOV 8 5 cm
49	Plotino et al. [75]	Italian White population	Italy	210	117	America	“Number of roots”	NewTom VGi vertical cone beam	Cross-sectional, descriptive, and prospective
								Not reported detail setting
50	Popovic et al. [76]	Serbian population	Serbia	192	118	Europe	“Number of roots”	Orthophos XG 3D	Cross-sectional, descriptive, and retrospective
								Voxel size 160 m
								Large FOV
51	Qiao et al. [77]	Chinese population	China	587	1174	East Asia	“Radix Entomolaris”	3D Accuitomo	Cross-sectional, analytical, and retrospective
								85 kVp
								4.5 mA
								FOV 60 × 60 cm
								Voxel size 0.125 mm
52	Razumova et al. [78]	Moscow population	Russia	300	407	Europe	“Number of roots”	3D Exam®	Cross-sectional, descriptive, and retrospective
								FOV 23 17 cm
								Voxel size 0.3
								110 kVp
53	Riyahi et al. [79]	Saudi Arabian population	Saudi Arabia	379	655	West Asia	“Three-rooted”	ProMax 3D	Cross-sectional, descriptive, and retrospective
								Voxel size 0.2–0.6 mm
54	Rahimi et al. [80]	Iranian population	Iran	386	Tooth-level data was not reported	West Asia	“Radix Entomolaris”	NewTom VG 9000	Cross-sectional, descriptive, and retrospective
								120 kVp
								150 mA
55	Rodrigues et al. [81]	Brazilian population	Brazil	116	232	America	“Radix Entomolaris”	i-CAT	Cross-sectional, descriptive, and retrospective
								120 kVp
								8 mA
								0.25 mm voxel size
56	Senan et al. [82]	Yemini population	Yemen	250	500	West Asia	“Radix Entomolaris”	Pax-Flex 3D	Cross-sectional, descriptive, and retrospective
								50–90 kVp
								2–10 Ma
								FOV 50 × 50 mm
								Voxel size 120 μm
57	Sharaan and Elrawdy [83]	Egyptian population	Egypt	109	218	Africa	“Radix Entomolaris”	Scanora 3D	Cross-sectional, descriptive, and retrospective
								Voxel size 133 μm
								10 mA
								90 kVp
								FOV 14 × 16.5 cm
58	Shehadat et al. [84]	UAE population	UAE	475	807	West Asia	“Three roots”	Not reported detail	Cross-sectional, descriptive, and retrospective
59	Shemesh et al. [2]	Israeli population	Israel	1020	1229	West Asia	“Radix Entomolaris” and “Radix Paramolaris”	ASAHI Alioth	Cross-sectional, descriptive, and retrospective
								85 kVp
								6 mA
								80 × 80 mm FOV
60	Silva et al. [85]	Brazilian population	Brazil	154	146	America	“3 separate roots”	i-CAT	Cross-sectional, descriptive, and retrospective
								120 kVp
								7 mA
								Voxel size 200 μm
								FOV 80 × 80 mm
61	Torres et al. [86]	Belgium population and Chilean population	Belgium	Belgium 100. Chile 170	145 (Belgium)	Europe and America	“Number of roots”	3D Accuitomo 170®	Cross-sectional, analytical, and retrospective
			Chile					90 kVp
					146 (Chile)			Voxel size 0.25 mm
62	Tredoux et al. [87]	South African population	South Africa	Patient-level was not reported	369	Africa	“Three-rooted”	Planmeca ProMax 3D Max	Cross-sectional, descriptive, and retrospective
								Voxel size 100–600 μm
								54–90 kVp
								1–14 mA
63	Tu et al. [88]	Taiwanese population	Taiwan	123	246	East Asia	“Extra DL”	i-CAT	Cross-sectional, descriptive, and retrospective
								Voxel size 0.2–0.4 mm
64	Wang et al. [89]	Western Chinese population	China	558	558	East Asia	“Extra distolingual root”	3D Accuitomo	Cross-sectional, descriptive, and retrospective
								Voxel size 0.125 mm
65	Wang et al. [90]	Mongoloid population	China	502	502	East Asia	“Three-rooted”	DCTPRO	Cross-sectional, descriptive, and retrospective
								FOV 16 × 7 cm
								0.20 voxel size
								90 kVp
								9 mA
66	Wu et al. [91]	Taiwanese population	Taiwan	233	466	East Asia	“Distolingual root”	NewTom 5G	Cross-sectional, analytical, and retrospective
								110 kVp
								11.94 mA
								FOV 30.5 cm² × 20.3 cm²
67	Wu et al. (A) [16]	Taiwanese population	Taiwan	300	600	East Asia	“Distolingual root”	NewTom 5G	Cross-sectional, analytical, and retrospective
								110 kVp
								11.94 mA
								FOV 30.5 cm² × 20.3 cm²
68	Wu et al. (B) [17]	Taiwanese population	Taiwan	400	800	East Asia	“Distolingual root”	NewTom 5G	Cross-sectional, analytical, and retrospective
								110 kVp
								11.94 mA
								FOV 30.5 cm² × 20.3 cm²
69	Xu et al. [92]	Chinese population	China	334	Tooth-level data was not reported	East Asia	“Distolingual root”	NewTom VGI	Cross-sectional, descriptive, and retrospective
								110 kVp
								2.79 mA
								FOV 8 cm × 8 cm
								Voxel size 0.125 mm
70	Zhang et al. [93]	Chinese population	China	211	232	East Asia	“Distolingual root”	3D Accuitomo	Cross-sectional, descriptive, and retrospective
								Voxel size 0.125 mm
								5 mA
								80 kVp
								FOV 40 × 40 mm
								60 × 60 mm
71	Zhang et al. [8]	Chinese population	China	455	910	East Asia	“DL”	Galileos	Cross-sectional, descriptive, and retrospective
								85 kVp
								35 mA
								0.125 voxel size
72	Zhang et al. [13]	Chinese population	China	83	83	East Asia	“Separate DL”	Galileos	Cross-sectional, descriptive, and retrospective
								85 kVp
								28–42 mA
								Voxel size 0.25 mm

Zero prevalence of three-rooted PMFM, (τ): foreign language translated to English, and ($): Spiral Computed Tomography (SCT).