applied
sciences
Re iew
Roo Canal Mo phology o he Pe manen Mandibula
Inciso s by Cone Beam Compu ed Tomog aphy:
A Sys ema ic Re iew
Sil ia He e o-He nández 1, Nansi López-Val e de 1,* , Manuel B a o 2,
Óli e Valencia de Pablo 3, Manuel Peix-Sánchez 1, Ja ie Flo es-F aile 1, Juan Manuel Ramí ez 4,
B uno Macedo de Sousa 5and An onio López-Val e de 1
1Depa men o Su ge y, Uni e si y o Salamanca, Ins i u o de In es igación Biomédica de Salamanca (IBSAL),
37007 Salamanca, Spain; sil ia_he e [email p o ec ed] (S.H.-H.); [email p o ec ed] (M.P.-S.); j. lo [email p o ec ed] (J.F.-F.);
[email p o ec ed] (A.L.-V.)
2Depa men o P e en i e and Communi y Den is y, Facul ad de Odon ología, Campus de Ca uja s/n,
18071 G anada, Spain; mb a o@ug .es
3Depa men o Endodon ics, Uni e sidad Eu opea, 28670 Mad id, Spain; [email p o ec ed]
4Depa men o Mo phological Sciences, Uni e si y o Co doba, A enida Menéndez Pidal s/n,
14071 Co doba, Spain; jm ami [email p o ec ed]
5Ins i u e o Occlusion and O o acial Pain Facul y o Medicine, Uni e si y o Coimb a, Polo I-Edi ício Cen al
Rua La ga, 3004-504 Coimb a, Po ugal; b [email p o ec ed]
*Co espondence: [email p o ec ed]; Tel.: +34-656238285
Recei ed: 24 June 2020; Accep ed: 13 July 2020; Published: 17 July 2020


Abs ac :
Knowledge o den al ana omy h ough he assessmen o he ana omic a ia ions o each
oo h’s oo canal sys em is essen ial o unde ake endodon ic he apy. The aim o his sys ema ic e iew
was o analyze he di e en s udies on he in e nal mo phology o pe manen mandibula inciso s whe e
Cone-Beam Compu ed Tomog aphy (CBCT) X- ay imaging is used. Pubmed, CENTRAL, Wiley Lib a y
and Web o Science elec onic da abases we e sea ched o scien i ic s udies included un il Ma ch 2020.
The e ms used in he sea ch we e: “pe manen mandibula inciso s”, “ oo canal mo phology” and
“cone-beam compu ed omog aphy”. The sea ch was limi ed o s udies whose aim was he analysis o
he mo phology o he oo canal sys em e alua ing he pa ame e s o me hodology, popula ion, sample,
numbe and con igu a ion. A o al o 19 s udies me he inclusion c i e ia. The e was a no iceable lack o
unanimi y in he se ing adjus men s o each o he CBCT de ices used. The p esence o wo oo canals
a ied om 0.4% o 45%. The mos equen con igu a ions we e Ve ucci’s Types I, III, II, V, IV, VII and VI.
Type VIII con igu a ion was non-exis en . CBCT e ealed he exis ence o ana omical symme y pa e ns,
and he e was no unanimi y o c i e ia ega ding he p esence o a second oo canal. Resul s conce ning
he p esence o a second oo canal in he mandibula inciso s di e widely, wi h a possible in luence
o he geog aphic a ea whe e he s udy was conduc ed. The p e alence o a second canal is highe in
mandibula la e al inciso s han in mandibula cen al inciso s. The e was no di ec ela ionship be ween
oxel size (0.125–0.3 mm) and inc eased p e alence o a second canal.
Keywo ds:
pe manen mandibula inciso s; oo canal mo phology; cone-beam compu ed
omog aphy (CBCT)
Appl. Sci. 2020,10, 4914; doi:10.3390/app10144914 www.mdpi.com/jou nal/applsci
Appl. Sci. 2020,10, 4914 2 o 15
1. In oduc ion
Good knowledge o he oo canal ana omy is essen ial o he success o any endodon ic ea men .
The de elopmen o new ma e ials and echniques has con ibu ed o inc easing he chances o ensu ing
good esul s. Ne e heless, ana omical knowledge is s ill he mos aluable ool when i comes o
add essing each sepa a e case and deciding which ma e ials and ools o use [1].
In 1984, Ve ucci d ew up a classi ica ion based on he di e en oo canal mo phologies [
2
]. Figu e 1
shows Ve ucci’s con igu a ion o he lowe inciso . The pu pose o his igu e, c ea ed by he au ho s,
is o p o ide a be e unde s anding o he classi ica ion.
Appl. Sci. 2020, 10, x FOR PEER REVIEW 2 o 15
1. In oduc ion
Good knowledge o he oo canal ana omy is essen ial o he success o any endodon ic
ea men . The de elopmen o new ma e ials and echniques has con ibu ed o inc easing he
chances o ensu ing good esul s. Ne e heless, ana omical knowledge is s ill he mos aluable ool
when i comes o add essing each sepa a e case and deciding which ma e ials and ools o use [1].
In 1984, Ve ucci d ew up a classi ica ion based on he di e en oo canal mo phologies [2].
Figu e 1 shows Ve ucci’s con igu a ion o he lowe inciso . The pu pose o his igu e, c ea ed by
he au ho s, is o p o ide a be e unde s anding o he classi ica ion.
Figu e 1. Ve ucci’s con igu a ion adap ed o he pe manen mandibula inciso .
O e ime, he s udy o in e nal oo canal mo phology has been app oached using di e en
me hodologies: adi ional adiog aphy, adiog aphy using adiopaque con as agen s, sec ioning,
scanning elec on mic oscopy, clea ing echnique, Cone-Beam Compu ed Tomog aphy (CBCT) and
mic o-Cone-Beam Compu ed Tomog aphy (µ-CT) [3–8]. Besides, in ecen yea s, he e has been an
inc ease in he numbe o published s udies on he mo phology o he oo canal sys em (Figu e 2).
Figu e 2. S udies acco ding o he U.S. Na ional Lib a y o Medicine da abase, using “ oo canals”
and “ana omy mo phology” as he keywo ds. Sou ce: U.S. Na ional Lib a y o Medicine. US Na ional
Lib a y o Medicine. h ps://www.nlm.nih.go (accessed on 28 Feb ua y 2020).
Inc ease in s udies un il Ap il 2020
Figu e 1. Ve ucci’s con igu a ion adap ed o he pe manen mandibula inciso .
O e ime, he s udy o in e nal oo canal mo phology has been app oached using di e en
me hodologies: adi ional adiog aphy, adiog aphy using adiopaque con as agen s, sec ioning,
scanning elec on mic oscopy, clea ing echnique, Cone-Beam Compu ed Tomog aphy (CBCT) and
mic o-Cone-Beam Compu ed Tomog aphy (
µ
-CT) [
3
–
8
]. Besides, in ecen yea s, he e has been an inc ease
in he numbe o published s udies on he mo phology o he oo canal sys em (Figu e 2).
Appl. Sci. 2020, 10, x FOR PEER REVIEW 2 o 15
1. In oduc ion
Good knowledge o he oo canal ana omy is essen ial o he success o any endodon ic
ea men . The de elopmen o new ma e ials and echniques has con ibu ed o inc easing he
chances o ensu ing good esul s. Ne e heless, ana omical knowledge is s ill he mos aluable ool
when i comes o add essing each sepa a e case and deciding which ma e ials and ools o use [1].
In 1984, Ve ucci d ew up a classi ica ion based on he di e en oo canal mo phologies [2].
Figu e 1 shows Ve ucci’s con igu a ion o he lowe inciso . The pu pose o his igu e, c ea ed by
he au ho s, is o p o ide a be e unde s anding o he classi ica ion.
Figu e 1. Ve ucci’s con igu a ion adap ed o he pe manen mandibula inciso .
O e ime, he s udy o in e nal oo canal mo phology has been app oached using di e en
me hodologies: adi ional adiog aphy, adiog aphy using adiopaque con as agen s, sec ioning,
scanning elec on mic oscopy, clea ing echnique, Cone-Beam Compu ed Tomog aphy (CBCT) and
mic o-Cone-Beam Compu ed Tomog aphy (µ-CT) [3–8]. Besides, in ecen yea s, he e has been an
inc ease in he numbe o published s udies on he mo phology o he oo canal sys em (Figu e 2).
Figu e 2. S udies acco ding o he U.S. Na ional Lib a y o Medicine da abase, using “ oo canals”
and “ana omy mo phology” as he keywo ds. Sou ce: U.S. Na ional Lib a y o Medicine. US Na ional
Lib a y o Medicine. h ps://www.nlm.nih.go (accessed on 28 Feb ua y 2020).
Inc ease in s udies un il Ap il 2020
Figu e 2.
S udies acco ding o he U.S. Na ional Lib a y o Medicine da abase, using “ oo canals” and
“ana omy mo phology” as he keywo ds. Sou ce: U.S. Na ional Lib a y o Medicine. US Na ional Lib a y
o Medicine. h ps://www.nlm.nih.go (accessed on 28 Feb ua y 2020).
Appl. Sci. 2020,10, 4914 3 o 15
All o hem ha e con ibu ed o c ea ing a de ailed ana omical map o pe manen mandibula inciso s,
con eying he ac ha he in e nal mo phology o such oo h is no simple and ha i is necessa y o
in oke a ia ions o Ve ucci’s classi ica ion [9].
CBCT o e s he ad an age o being a highly accu a e echnique ha p o ides h ee-dimensional
images in a non-in asi e way, exposing pa ien s o lowe doses o adia ion han o he echniques such as
adi ional compu ed omog aphy. I s use in he assessmen o oo canal mo phology has been endo sed by
he Eu opean Socie y o Endodon ology and p o ides clinicians wi h e idence-based c i e ia. The g ea es
disad an age o CBCT in he s udy o den al ana omy is he p esence o image a i ac s caused by he
p esence o highly adiopaque ma e ials om he illing and es o a ion o he oo h o esul ing om o he
ac o s such as he pa ien ’s mo emen s [10]. Likewise, in in i o s udies, he s ong impac o he use o
CBCT as a me hod o s udy he oo canal sys em is e lec ed in he high numbe o samples ob ained in
some clinical ials, allowing adequa e s a is ical analysis in p e alence s udies [11].
Failu e o endodon ic ea men is usually a cause o conce n o bo h clinicians and pa ien s. Von A x
iden i ied he p esence o is hmuses o un ea ed canals as he main cause o endodon ic he apy ailu e [
12
].
Lack o knowledge o ana omy and, consequen ly, missing un ea ed canals is highly associa ed wi h he
p esence o pe iapical lesions. Speci ically, as ega ds such lesions, he p e alence a e o missed canals
anges be ween 12.2% and 17.4% in cen al and la e al mandibula inciso s, espec i ely [
13
]. These da a
should encou age clinicians o sea ch o a mo e complex in e nal ana omy and e eal he impo ance o
chemo-mechanical p epa a ion o he oo canal as he main s a egy o i s disin ec ion [14].
On he o he hand, he e a e widely di e ing da a on he exis ence o a second oo canal.
Repo ed pe cen ages ange om 0.4% [
15
] o 70% [
16
] when none o he me hodologies we e excluded.
This ende s i necessa y o elimina e he he e ogenei y as ega ds he me hodology used.
The pu pose o his s udy was o ca y ou a sys ema ic e iew on he mo phology o he oo canal
sys em in pe manen mandibula inciso s, assessed using CBCT in human clinical s udies, wi h oxel sizes
o up o 0.3 mm. We belie e ha his sys ema ic e iew will con ibu e o he unde s anding o he widely
di e ing esul s exp essed in he li e a u e as ega ds he p esence o a second oo canal and o he inding
o possible explana ions, as well as o he sea ch o he lowes adia ion dose possible o he s udy o
in e nal ana omy.
2. Me hods
The s udy was planned and s uc u ed acco ding o he PRISMA guidelines (P e e ed Repo ing
I ems o Sys ema ic Re iew and Me a-analysis) [17].
2.1. P o ocols
The sea ch s a egy was conduc ed using he condi ion, con ex and popula ion amewo k (CoCoPop),
based on he ollowing ques ion: “Wha is he p e alence o oo canal con igu a ion o he pe manen
mandibula inciso s?”. To answe his ques ion, he condi ion was he mo phology o he oo canal
sys em in he mandibula inciso s. Only s udies ha used an
in i o
CBCT me hodology we e included.
The con ex included all he
in i o
s udies ca ied ou using CBCT, wi hou excluding any coun y
in he wo ld. The popula ion consis ed o pa ien s who had been subjec ed o CBCT, ega dless o i s
diagnos ic pu poses.
2.2. Sea ch Me hod o he Iden i ica ion o S udies
A bibliog aphic sea ch o he Pubmed, CENTRAL, Wiley Lib a y and Web o Science elec onic
da abases was conduc ed in o de o iden i y he mos ele an s udies a ailable un il 28 Ma ch 2020.
The pu pose was o iden i y
in i o
p e alence s udies whe e he canal sys em o he pe manen mandibula
Appl. Sci. 2020,10, 4914 4 o 15
inciso s was analyzed using CBCT. The las upda e was made on 1 July 2020. The sea ch e ms we e
“pe manen mandibula inciso s”, “ oo canal mo phology”, “cone-beam compu ed omog aphy” and
“CBCT”. The keywo ds we e used indi idually o in combina ion, using he boolean ope a o s “AND”,
“OR”, “NOT” o independen ly sea ch o he e m “cone-beam compu ed omog aphy” o i s abb e ia ion
(“CBCT”), include all e ms, o exclude “pe manen mandibula inciso ” because o he possibili y o
inding s udies ha e alua ed all den al g oups. The sea ch was comple ed manually by eading wo
endodon ic jou nals: Jou nal o Endodon ics and In e na ional Jou nal o Endodon ics.
2.3. Inclusion and Exclusion C i e ia
The inclusion c i e ia co e ed s udies ha e alua ed he con igu a ion o he oo sys em o he
pe manen mandibula inciso s and ha we e published in English. Fu he mo e, he e alua ion o he
canals had o indica e no only he p esence o a second canal bu also i s in e nal con igu a ion using
Ve ucci’s classi ica ion. Exclusion c i e ia we e s udies ha did no use CBCT as a diagnos ic ool,
in i o
s udies, sys emic e iews, case epo s, and duplica e s udies. Besides, hose ha did no indica e he
numbe o samples and pa ien s who pa icipa ed in he s udy, o whose samples had been pa ially
analyzed in o he included s udies, we e excluded.
2.4. Da a Ex ac ion and Analysis
Fi s , wo e iewe s (SH-H and NL-V) unde ook he eading o all he i les and abs ac s, and hose
ha did no e e o he esea ch ques ion we e emo ed. Subsequen ly, he a o emen ioned e iewe s
conduc ed an independen e alua ion, ollowing he inclusion/exclusion c i e ia, un il eaching a consensus
on he s udies o be included in he s udy. Finally, a o al o 19 s udies we e included and he ull ex s
o he selec ed s udies we e ob ained o e iew. The ex ac ion o da a om each s udy was pe o med
using Excel sp eadshee s, comple ing he ollowing ca ego ies: yea o publica ion, sample size, coun y,
pe cen age o a second canal, Ve ucci’s con igu a ion, o he ele an esul s, CBCT model, oxel size, FOV,
CBCT se ings and so wa e isualiza ion.
2.5. Quali y o he Repo s o he Included S udies
We used he STROBE ecommenda ions checklis adap ed by Ma ins e al. o c oss-sec ional s udies
on oo and oo canal ana omy using CBCT, as a p oxy indica o o quali y [
18
]. The objec i e o he
checklis is o assess limi a ions and isk o bias in he s udies, which could lead o an e oneous eading o
he esul s. In addi ion, i inc eases he alidi y and s eng h o he indings and he ep oducibili y o
he me hod, and i is an indica o ha imp o es he o e all quali y o he p e alence s udies. Each i em
was assessed by e iewe s S.H.-H. and N.L.-V., who a ibu ed sco es o 0 (no epo ed) o 1 ( epo ed),
ca ying ou a comple e coun o all he s udies included.
3. Resul s
3.1. Cha ac e is ics o he S udies
A o al o 2290 s udies we e ga he ed and analyzed. O hese, 2219 we e emo ed because o hei
being duplica es o no ela ed o he s udy. O he emaining 71 s udies, 52 we e emo ed due o lack
o ele ance, no using CBCT as hei diagnos ic me hodology, o being
in i o
ials, case s udies o
sys ema ic e iews, lea ing a o al o 19 s udies [
8
,
14
,
19
–
35
] (Figu e 3. Flowcha ). Table 1includes he
in o ma ion co esponding o each o he assessed s udies including hei i ems: popula ion, sample,
second oo canal pe cen age, Ve ucci classi ica ion (%) and o he esul s. Table 2shows he de ails o each
s udy ega ding he pa ame e s used in he CBCT imaging p ocess.
Appl. Sci. 2020,10, 4914 5 o 15
Appl. Sci. 2020, 10, x FOR PEER REVIEW 5 o 15
he in a and in e a e eliabili y es ). Fu he mo e, i was in e es ing o no e how all he s udies
used he wo d “Cone-beam compu ed omog aphy o CBCT” in he i le, bu none o hem men ioned
he ype o s udy (Table 3).
Figu e 3. Flowcha o he s udy selec ion p ocess. PRISMA (P e e ed Repo ing I ems o Sys ema ic
Re iew and Me a-Analyses) [17].
Figu e 3.
Flowcha o he s udy selec ion p ocess. PRISMA (P e e ed Repo ing I ems o Sys ema ic
Re iew and Me a-Analyses) [17].
3.2. Quali y o he Repo s o he Included S udies
The e alua ion o “speci ic p e e ed epo ing i ems o c oss-sec ional s udies on oo and oo
canal ana omy using cone-beam compu ed omog aphy (CBCT)” [
18
] demons a ed ha 50% o he i ems
we e epo ed in all o he published s udies. The i ems ha we e mos equen ly dis ega ded by he
esea che s we e “ u u e esea ch” (no indica ed in 78.9% o he s udies), “s eng hs and limi a ions”
(68.4% o he s udies ailed o assess limi a ions) and “ eliabili y” (52.6% did no pe o m he in a and
in e a e eliabili y es ). Fu he mo e, i was in e es ing o no e how all he s udies used he wo d
“Cone-beam compu ed omog aphy o CBCT” in he i le, bu none o hem men ioned he ype o s udy
(Table 3).

Appl. Sci. 2020,10, 4914 6 o 15
Table 1. Roo canal con igu a ion o pe manen mandibula inciso s.
S udy/Yea nCoun y 2nd Roo Canal
Ve ucci
O he Ou comes
I II III IV V VI VII O he s
Bax e e al./2020 [7]604 CI
604 LI
Ge many
22.6%
24.3%
76.1%
76.6%
22%
21.3% -0.6%
1%
1.1%
1% - - 0.2%
0.1%
Symme y: Type I: 77% (CI),
77% (LI); Res o ypes: 17.5%
(CI), 20.5% (LI).
S oczyk e al./2019 [19]212 CI
208 LI Poland 34.1%
31.8%
65.4%
67.2%
1%
0.9%
26.4%
25%
-
0.5%
5.3%
3.9%
- 1%
-
0.9%
2.5%
Symme y: Type I: 54.86% (CI),
56.12% (LI). Res o ypes:
23.53% (CI), 19,19% (LI).
Mashyakhy e al./2019 [20]410 CI
412 LI
Saudi
A abia
26.3%
30.8%
73.7%
69.2% -26.3%
29.8% --
1% - - - Symme y: 91.2% (CI),
85.8% (LI).
Mi hosseini e al./2019 [21]330 CI
351 LI I an 23.9%
35%
76.1%
65%
0%
0.6%
15.8%
15.7%
0.6%
0.9%
7.6%
17.8% - - - % 2nd oo canal: LI >CI
Pan e al./2019 [22]408 CI
400 LI
Malaysia
5.1%
12.3%
94.9%
87.8% -1%
3.7% 0.3%
4.1%
8.2% - - - -
Valen i-Obino e al./2019 [23]487 CI
491 LI I aly 45%
43%
55%
57%
34.3%
35.7%
9.3%
6.9%
0.6%
-- - 0.8%
0.4% -Symme y: 44.6% (CI),
44.8% (LI).
Ma ins e al./2018 [15]
240 CI
240 LI
1203 CI
1234 LI
China
Po ugal
0.4%
5%
27.4%
29.9%
99.6%
95%
72.6%
70.1%
-
2.9%
2.4%
6.1%
0.4%
0.8%
24%
23.1%
-
-
0.1%
-
-
1.3%
0.3%
0.2%
-
-
-
-
-
-
0.5%
0.2%
-
-
0.1%
0.3%
The Asian g oup ha e a highe
p e alence o Ve ucci ype I
con igu a ion compa ed o he
whi e e hnic g oup.
Wu e al./2018 [24]800 CI Taiwan 15.6% 84.4% - 13.5% 2.1% - - -
Co ela ion be ween
complica ed oo canal CI-DLR
in PMFM.
Saa i e al./2018 [25]207 CI
207 LI I an 15.5%
21.8%
54.5%
56.5% -34.2%
26.1% -11.3%
17.4% - - - -
Shemesh e al./2018 [26]1472 CI
1508 LI Is ael 40.5%
37.9%
59.5%
62.1%
4%
4.3%
33.7%
31.9%
0.8%
0.4%
0.5%
0.5% - - 1.5%
0.8%
Symme y: 69.8% (CI),
68.7% (LI).
Ve ma e al./2017 [27]400 CI
400 LI India 31.8%
35%
68.3%
65%
11%
13.2%
15.3%
15.2%
1.7%
3.0%
3.7%
3.6% - - - % 2nd oo canal: LI >CI
Da Sil a e al./2016 [28]200 CI
200 LI B azil 35.5%
39.5%
64.5%
60.5%
-
0.5%
18%
25.5%
-
-
14.5%
12%
0.5%
-
2.5%
1.5% - -
Zhengyan e al./2016 [29]3375 CI
3257 LI China 3.8%
10.6%
96.2%
89.4%
0.1%
1%
2.7%
7.7%
0.1%
0.3%
0.7%
1.2% - - 0.2%
0.4% 2nd oo canal >LI women
Geduk e al./2015 [30]1438 I Tu key 3.6% 64.4% 15.2% 19.4% 0.2% 0.8% - - - 2nd oo canal >41–50 yea s
Appl. Sci. 2020,10, 4914 7 o 15
Table 1. Con .
S udy/Yea nCoun y 2nd Roo Canal
Ve ucci
O he Ou comes
I II III IV V VI VII O he s
Al unsoy e al./2014 [31]1582 CI
1603 LI Tu key 15.3%
19.2%
84.4%
80.2%
0.4%
1.3%
0.8%
1.0%
4.3%
5.4%
10.1%
12.1% - - - 2nd oo canal: men >women
Han e al./2014 [32]1286 CI
1294 LI China 15.7%
27.4%
84.3%
72.6%
3.4%
4.0%
6.5%
15.5%
1.2%
2.3%
3.9%
5.1%
-
0.2%
0.3%
0.2%
0.4%
0.1%
IL >IC. Dis ance apex- oo
canal bi u ca ion: 6–12 mm.
Lin e al./2014 [33]706 CI
706 LI China 10.9%
25.5%
89.1%
74.5%
2.4%
3.7%
6.2%
19.3%
1.7%
2.1%
0.6%
0.4% - - - Symme y: 95.2% (CI), 93.8%
(LI).2nd oo canal: LI >CI
Liu e al./2014 [34]786 CI
785 LI China 8.9%
17.5%
91.1%
82.5%
2.0%
3.9%
5.3%
10.4%
1.3%
2.8%
0.3%
0.3% - - - -
Aminsobhani e al./2013 [35]632 CI
614 LI I an 27.3%
29.4%
72.7%
70.6%
11.3%
7.1%
4.7%
3.7%
7.7%
15.4%
3.6%
3.2% - - -
AV: 21.3
±
0.10 (CI), 21.9
±
0.13
(LI). No gende di e ence
n(numbe o inciso s); CI (cen al inciso ); LI (la e al inciso ); DLR (dis olingual oo ); PMFM (pe manen mandibula i s mola ); I (inciso s); AV (a e age leng h).
Table 2. Cone-beam compu ed omog aphy pa ame e alues o each s udy.
S udy/Yea Coun y % 2nd Roo Canal CBCT Model Voxel Size FOV Se ings CBCT So wa e Visualiza ion
Bax e e al./2020 [7]Ge many 23.45% Galaxis Galileo (Si ona,
Bensheim, Ge many) 0.3 mm 15 cm385 K /5–7 mA/-
S oczyk e al./2019 [19]Poland 32.9% C anex 3D (So edex, Tuusula,
Finland) - - - Ho os
Mashyakhy/2019 [20]Saudi
A abia 28.55% 3D Accui omo 170 (Mo i a,
Kyo o, Japan) 0.25 mm - 90 K /5–8 mA/17.5 s. Mo i a’s i-Dixel 3D
Mi hosseini e al./2019 [21]I an 23.9% Planmeca P oMax 3D (Planmeca,
Helsinki, Finland) 0.2 mm 100 ×70 ×50 mm 90 K /10 mA/14 s. Planmeca Romexis
Pan e al./2019 [22]Malaysia 17.4%
KaVo 3D eXam (Imaging Sciences
In e na ional, Ha ield, PA, USA) 0.25 mm - 120 kV/5 mA/26.9 s. eXam Vision
Valen i-obino e al./2019 [23]I aly 44% GXDP-500 sys em (Gendex
Den al, Bibe ach, Ge many) 0.2 mm 13 ×9×13 cm 90 kV/7 mA/23 s. Ho os
Ma ins e al./2018 [15]China 2.7%
Kodak 9500 (Ca es eam, A lan a,
GA, USA) 0.2 mm Full a ch. 90 kV/10 mA/10.8 s. CS 900 3D imaging
Ma ins e al./2018 [15]Po ugal 28.6% Planmeca P oMax 3D (Planmeca,
Helsinki, Finland) 0.2 mm Full a ch 80 kV/15 mA/12.0 s. Planmeca Romexis
Wu e al./2018 [24]Taiwan 15.6% NewTom 5G (QR, Ve ona, I aly) - Full a ch 110 kV/11.94 mA/7 s. -
Appl. Sci. 2020,10, 4914 8 o 15
Table 2. Con .
S udy/Yea Coun y % 2nd Roo Canal CBCT Model Voxel Size FOV Se ings CBCT So wa e Visualiza ion
Shemesh e al./2018 [25]Is ael 39.2% Asahi Alio h (Asahi Roen gen
IND, Kyo o, Japan) 0.155 mm 80 ×80 mm 85 kV/6 mA OnDemand 3D
Saa i e al./2018 [26]I an 18.6% NewTom 5G (QR, Ve ona, I aly) 0.25 mm - 110 kV/2.5–6.7 mA/12 s. NNT Viewe
Ve ma e al./2017 [27]India 33.5% Galaxis Galileo (Si ona,
Bensheim, Ge many) - - 98 kV/5–15 mA -
Da Sil a e al./2016 [28]B azil 37.5% i-CAT (Imaging Sciences
In e na ional, Ha ield, PA, USA) 0.2 mm - 120 kV/7 mA/40 s. i-CAT
Zhengyan e al./2016 [29]China 7.2% - 0.125 mm - 120 kV/5 mA/9–18 s. i-CAT
Geduk e al./2015 [30]Tu key 3.6% Galaxis Galileo (Si ona,
Bensheim, Ge many) - - 98 kV/15–30 mA SIDEXIS XG
Al unsoy e al./2014 [31]Tu key 17.3% i-CAT (Imaging Sciences
In e na ional, Ha ield, PA, USA) 0.3 mm - 120 kV/9–14 mA/6 s. -
Han e al./2014 [32]China 21.7% Galaxis Galileo (Si ona,
Bensheim, Ge many) 0.125 mm - 85 kV/35.0 mA/2–6 s. SIDEXIS XG
Lin e al./2014 [33]- - - - - -
Liu e al./2014 [34]China 13.2% i-CAT (Imaging Sciences
In e na ional, Ha ield, PA, USA) - - 120 kV/5 mA/9–18 s. eXam Vision
Aminsobhani e al./2013 [35]I án 28.35% Planmeca P oMax 3D (Planmeca,
Helsinki, Finland) - - - Planmeca Romexis
FOV (Field o View).
Appl. Sci. 2020,10, 4914 9 o 15
Table 3.
Speci ic P e e ed Repo ing I ems o C oss-sec ional S udies on Roo and Roo Canal Ana omy
Using Cone-beam Compu ed Tomog aphic (CBCT).
Sec ion and I em n(%)
1. Ti le 19 100
In oduc ion
2. Keywo ds 19 100
3. Aim 19 100
Me hods
4. Pa icipan s (in i o assessmen ) 19 100
5. CBCT 19 100
6. Mo phology concep and assessed ee h
( a iables) 19 100
7. Assessmen 19 100
8. Obse e s 13 68.4
9. Po en ial sou ces o bias 15 78.9
10. Final simple size 15 78.9
11. Reliabili y 9 47.4
12. S a is ical analysis 13 68.4
13. E hics Commi ee 13 78.9
Resul s
14. P ima y ou comes 19 100
15. O he analysis 15 78.9
16. Visual documen a ion suppo 16 84.2
Discussion
17. Ou comes in e p e a ion 19 100
18. S eng h and limi a ions 6 31.5
19. Gene alizabili y 19 100
20. Fu u e esea ch 4 21.0
3.3. Syn hesis o S udies Included
The e is unanimi y ac oss he s udies ega ding he ac ha ype I is he mos equen con igu a ion.
The es o Ve ucci’s con igu a ions we e conside ed inciso s wi h wo canals, ega dless o hei pa h
in he canal sys em. When he e we e wo canals, he mos equen classi ica ion was ype III, wi h he
excep ion o ou s udies [
8
,
22
,
23
,
35
]. The e was no he e ogenei y as o he equency o he es o
con igu a ions, wi h s udies whe e he nex mos equen con igu a ions we e ype II [
14
,
23
,
26
,
27
,
30
,
33
,
34
],
ype V [
8
,
19
–
21
,
24
,
25
,
28
,
29
,
32
], o ype IV [
31
]. The emaining ypes [VI, VII and o he s] we e gene ally
p esen in e y low o non-exis en pe cen ages. Fi e s udies epo ed symme y be ween he inciso s on
he igh and le side o he pa ien [
8
,
19
,
20
,
23
,
26
,
33
]. La e al inciso s showed a highe p e alence in he
exis ence o a second canal compa ed o cen al inciso s in ou een s udies [
7
,
14
,
20
–
22
,
25
,
27
–
29
,
31
–
35
].
The cen al inciso had a highe p e alence in only h ee [
19
,
23
,
26
]. Likewise, we calcula ed he weigh ed
a e age o all he pe cen ages in he exis ence o a second canal, ob aining 17.2% in he cen al and 23.7%
in he la e al inciso s. Only wo s udies epo ed a ela ionship be ween age and he p esence o a second
canal [
24
,
29
]. The emaining s udies did no assess pa ien age o , i so, did no ind any signi ican
di e ences [
8
,
30
]. Rega ding gende in luence, he e was no unanimi y as o a highe p e alence o second
canals in men [
19
,
20
,
24
,
31
] han in women [
27
,
29
], and he e we e e en ce ain s udies whe e no signi ican
di e ences we e ound [
8
,
22
,
25
,
30
,
34
,
35
]. Geog aphical dis ibu ion indica ed a lowe incidence o a
second canal in he Chinese popula ion [
14
,
29
,
32
–
34
]. The e was no di ec ela ionship be ween oxel size
and he inc eased p e alence o a second canal.