Table 2 Characteristics of the included CBCT in-vivo studies

[47]

Ghabbani, H.M., A.A. Marghalani, and H.R. Alabiri 2021

1624

Mandibular incisors

CS 9300 PREMIUM 3D (Carestream, Rochester, NY, USA)

0.3 mm

Blue Sky Plan

Vertucci’s classification

Retrospective data from database

Study found that 24.6% of mandibular central incisor had type I configuration then type III in 21.5% followed by type V in 2.4% of teeth, while the mandibular lateral incisor had 25.6% type I, 20.6% type III and 7.1% type V. Occurrence of type IV and VII was less, on the other hand type II, VI and type VIII were absent. With regards to gender females had 64.8% type I canals followed by 29.4% type III root canals, whereas 46.9% type III configuration was showed by males’ teeth then 45.2% of type I canal configuration.

Study concluded that all the mandibular incisors in the study had one root and increased incidence of one canal configuration. Canal configuration revealed bilateral symmetry in majority of mandibular incisors.

[48]

Mashyakhy, M 2019

822

Mandibular incisors

3D Accuitomo 170 (MORITA, Japan)

0.25 mm

Morita’s i‑Dixel 3D imaging software

Vertucci’s classification

Retrospective data from database.

Findings in the central incisors are as follows:

One root in 100% teeth, one canal in 73.7%, two canals in 26.3%, type Iin 73.7% and type III in 26.3%. Lateral incisor had one root in 99.5% teeth, two roots in 0.5%, one canal in 69.2%, two canals in 30.8%, type I in 69.2%, type III in 29.8% and type V configuration in 1.0% of teeth. Both the incisors had no statistical difference, but gender difference was seen in central incisor while it was absent in lateral incisor.

Few canals and their configuration showed bilateral asymmetry which can be of clinical importance.

[49]

Mohamed, A.N., et al. 2021

376

Mandibular incisors

Galileos ComfortPLUS System Sidexis

0.5 mm

SIDEXIS XG (Sirona 3D, Germany)

Vertucci’s classification

Retrospective data from database.

It was discovered that all the lower incisors had one root and occurrence of canal configuration is: type I-44.4%, type II-8%, type III-44.9% and type V was 2.1%.

Study concluded that majority of mandibular canines had one root and type IIIcanal configuration.

[50]

Alaboodi, R.A., S. Srivastava, and M.Q. Javed 2022

928

Mandibular incisors

GALILEOS Comfort CBCT

machine (Dentsply- Sirona Dental Systems,

Montagematerial, Galileos, SK, Bensheim,

Germany)

0.3-0.15 mm

Sidexis XG

3D Viewer; Germany

Vertucci’s classification

Retrospective data from database

Study stated that all the lower incisors had one root and chances of more than one canal was 29.3% in CI and 38.57% in LI. Canal configuration in central incisor is: Type-I (70.6%); Type-III- (24.5%); Type-II (3.4%); Type-IV (0.9%) and Type-V- (0.5%). Type-VI, VII and VIII were absent.

Lateral incisor had (61.6%) Type-I; Type-III (31.8%); Type-II (4.3%); Type-IV (0.8%); Type-V (1.3%) and

Type-VII (0.2%). Type-VI and VIII were absent. Oval canals were present in 46.6% teeth and was higher in type III (80.1%) than type I (322%).

Although mandibular incisors had single root, but canals varied in terms of numbers and configuration along with presence of oval canal higher in type III configuration.

[51]

Al-Dahman, Y., et al. 2019

454

Mandibular canines

CS9300 3D digital imaging

system (Carestream, Rochester, NY) and Planmeca ProMax 3D (PLANMECA,

90–300 μm,

≤ 200 μm

Planmeca Romexis

Viewer software (PLANMECA, Roselle, IL, USA)

Vertucci’s classification

Retrospective data from database

Study found that 99.8% of mandibular canines had one root and double root was seen in 0.2% which were men. 98% of females had one canal while 92.4% of single canal was seen in male. Predominant canal configuration was type I (95.4%) followed by type II (2.6%), type III (1.8%) and type IV (0.2%).

It was concluded that single root and canal with type I configuration was predominant finding although variations exist.

[52]

Almohaimede, A., et al. 2022

1370

Permanent mandibular incisors

Planmeca ProMax 3D (PLANMECA, Roselle, IL, USA) and a CS9300 3D digital imaging system (Carestream, Rochester, NY)

75–600 μm

Planmeca Romexis Viewer software (Planmeca, Roselle IL)

Vertucci’s classification

Retrospective data from database

Central incisor had 100% one root and 99.9% of lateral incisor had one with 0.1% two roots. One canal was noted in 58.8% and two canals in 41.2% with no difference between central and lateral incisor but women had increased frequency of two canals (57.09%) than men (42.9%).

Canal configuration is type I (58.83%), type III (28.24%), type II (6.4%), type V (5.76%) and type IV (0.72%).

It was evident from the results that Saudi population commonly had more than one canal and bilateral symmetry was more in central incisor than lateral incisor with respect to number of roots, canals and their configuration type.

[53]

Alobaid, M.A., et al. 2022

1260

Mandibular central incisors

KAVO OP 3D Pron (KaVo Dental, Charlotte, NC, USA)

0.85 mm

On demand 3DTM imaging software (Cybermed Inc.,

Unit K Tustin, CA)

New system of classification

Retrospective data from database

All the right and left lower central incisors were single rooted on both the sides.

Canal configuration in left central incisor: Male: 80.2% were (1-1-1),

13.6% had (1-2-1), 2.2% had (1-1-2),

3.7% had (1-2-2), and 0.4% were (2-2-1). Female: 84.4% were (1-1-1),

12.5% were (1-2-1), 2.5% had (1-2-2), and 0.6% were (2-2-1).

Canal configuration in right central incisor: Male: 77.0% were (1-1-1), (1.1%) were (1-1-2), 16.3% were (1-2-1), 4.8% were (1-2-2), 0.4% were (2-1-1), and 0.4% were (2-2-1). Female: 84.9% had (1-1-1) configuration, 12.6% had (1-1-2), 2.0% were (1-2-2), and 0.6% had (2-2-1).

As per the study more observed classification

was 1ManA1(82.6%) (Vertucci type I), then 1ManA1-2-1 was 13% (Vertucci type III). Canal configuration was symmetrical among the incisors with prevalence of single canal, but complex root morphology was also noted.

[54]

Alshayban, M., et al. 2022

1769

Mandibular anterior

Planmeca Promax 3D Max Digital Imaging Device (Planmeca, Helsinki, Finland)

160 μm

Planmeca Romexis_ 3.6 viewer

software (Planmeca, Helsinki, Finland).

Vertucci’s classification

Retrospective data from database

One root was 100% in lower central and lateral incisor while 98.4% of one root was seen in canine. Type I configuration was major among the lower anterior whereas 36.5% of type III was noted in central and 31% in lateral incisor.

Regarding the sex, females had higher frequency of type I than type III while males had higher chances of type III.

Study concluded that majority of included Saudi population had single root and one canal while few central and lateral incisors were found with two canals.

[55]

Alqedairi, A., et al. 2018

652

Maxillary first and second premolars

CS9300 3D digital imaging system (Carestream, Rochester, NY) and Planmeca ProMax 3D (Planmeca, Roselle IL).

90–300 μm and

≤ 200 μm

Planmeca Romexis Viewer software (Planmeca, Roselle IL).

Vertucci’s classification

Retrospective data from database.

Predominantly maxillary first premolar was double rooted (75.1%) with type IVcanal configuration (69.1%) whereas second premolar was single rooted (85.2%) with type I (49.4%) canal system. Excluding type VII configuration in second premolar, all types were seen in both the premolars.

Researchers concluded that one root and type IV canal configuration is prevalent in first maxillary premolar however two roots and type 1 was common in second premolar. First premolars had one canal (21.3%), two canals (75.4%), three canals (3.3%) apically whereas second premolar exhibited one canal (80.2%), two canals (18.9%), and three canals (0.9%) apically.

[56]

Al‑Zubaidi, S.M., et al. 2021

1000

Maxillary first and second premolars

Carestream CS 8100 3D (Carestream Dent LLC, Atlanta, USA).

75 μm

CS 3D Imaging Software (Carestream Dent LLC, Atlanta, USA).

Vertucci’s classification

Retrospective data from database.

It was discovered that out of 500 first maxillary premolars, 39.8% had single roots, 58.6% were double rooted followed by three roots (1.6%). Most common root canal configuration was type IV (57.8%) then type II (32.8%). 83.2% of second maxillary premolar had single root followed by two roots (15.8%) and three roots (1.0%).

Type Iconfiguration was common in second premolar (60.4%) then type II (16.4%).

Two canals and two roots were major finding in first maxillary premolars while one canal and single root was common in maxillary second premolar.

[57]

Mashyakhy, M 2021

710

Maxillary first and second premolars

3D Accuitomo 170 (MORITA, Japan)

0.25 mm

Morita’s i‑Dixel 3D imaging software

Vertucci’s classification

Retrospective data from database.

Occurrence of roots, canals and their configuration in first premolar are as follows:

1 root-40.7%, 2 roots- 57.5%, 3 roots-1.7%, 1 canal-3.7%, 2 canals-93.2%, 3 canals- 2.6%, 4 canals-0.4%, type II- 6.8%, type III- 7.7%, type IV- 63.8% and type V-14.8%. Similarly, upper second premolar had 1 root in 88% of teeth, 2 roots in 12%, 1 canal in 38.2%, 2 canals in 61.0%, 3 canals in 3 teeth, then type I in 38.2%, type IIIin 15.3%, type IVin 19.2% and type V in 12.3%.

Frequency of two roots and type IVwas high in upper first premolar while single root and type Iwas predominant in second premolar. Majority of upper premolars had two canals.

[32]

Al-Zubaidi, S.M., et al. 2022

1000

Mandibular first and second premolars

Carestream CS 8100 3D CBCT (Carestream Dent LLC, Atlanta, USA)

75 m

CS 3D Imaging Software (Carestream Dent LLC, Atlanta, USA).

Vertucci’s classification

Retrospective data from database.

Study analyzed that 95.5% of first mandibular premolars had single root and two roots were present in 4.5%, 70% of the teeth were accounting for type Ithen type II (14.2%) and type IV was (10.1%). In case of second mandibular premolar 99.2% samples had single root and two roots were found only in four teeth (0.8%). Similarly type I was the highest canal configuration (91.1%) then type II (5.7%)

According to the study incidence of one root and type I canal classification was higher in Saudi sub population although different configurations were present in several roots.

[58]

Alfawaz, H., et al. 2019

734

First and second mandibular premolars

CS9300 3D digital imaging system (Carestream, USA) and Planmeca ProMax 3D (PLANMECA, USA)

90–500 μm and

≤ 200 μm

Planmeca Romexis Viewer software (Planmeca, Roselle IL).

Vertucci’sx classification

Retrospective data from database

Type 1 root canal configuration and one root was the prominent finding in mandibular first (96.4%) and second (95.6%) premolar, however type VII was absent in first and type VI & VII were not seen in second premolar.

Bilateral symmetry was 93.8%and 97.8% in terms of roots and canal configuration in both the premolars.

Study revealed that one root and canals with type 1 configuration was the prominent finding in mandibular premolars of Saudi population, however premolars with more than one root and varying canal configuration was detected.

[59]

Alghamdi, F.T. and W.A. Khalil 2022

2400

Mandibular second premolar

i-CAT 1719 3D digital imaging system (Imaging Sciences International, Hatfield, PA, USA)

90–200 μm

OnDemand 3D Imaging Software (Cybermed, Seoul, South Korea)

Vertucci’s classification

Retrospective data from database.

Study discovered that 98.33% of mandibular second premolar had one root and 1.67% were two rooted,

occurrence of two roots on right side was higher in females compared to left side but this was in contrast with male patients.

97.91% of teeth had type I canal configuration, then type II (1.17%) and type IV (0.58%). Significant difference with regard to gender and size was revealed by only type I and type II canal configuration.

The study exhibited that root and canal morphology of second mandibular premolar varies greatly with increased prevalence of one root and one canal and less frequency of two roots.

[60]

Mashyakhy, M., et al. 2022

776

Mandibular premolars

3D Accuitomo 170 Morita; Osaka, Japan

0.25 mm

Morita’s i‑Dixel 3D

Vertucci’s classification

Retrospective data from database.

Occurrence of roots, canals and their configuration in the first mandibular premolar are as follows: 1 root-99.5%, 1 canal-69.5%, 2 canals- 29.5%, type I-69.5%, type III-6.3%, type V-22.2% and type VII-0.3%.

Likewise, second premolar had: 1 root-100%, 1 canal-96.8%, 2 canals-2.1%, type I-96.8%, type III-1.6% and type V-0.8%.

Study indicated that mandibular first and second premolars had single root and one canal in majority along with few variations.

[61]

Alam, F., et al. 2020

1504

Mandibular first and second premolars

Scanora 3D equipment (Soredex, Finland)

Retrospective data from database

Findings in the first premolar:

One root-80.85%, two roots-19.14%, one canal-71.27% and two canals-28.72%.

Second premolar: One root-88.29%, two roots-11.70%, one canal-71.80% and two canals-28.19%. Statistically significant difference was noted among males and females in case of number of roots of first premolar.

Study stated that variations in number of roots and canal of first and second mandibular premolars is common among males and females of included Saudi population.

[62]

Algarni, Y.A., et al. 2021

216

Mandibular first premolar

0.125 mm

CS 3D Imaging Software (Carestream Dental)

Vertucci’s classification

Retrospective data from database

Incidence of canals in females: one canal: 79.2%, two canals: 15.8%, three canals: 5%.

Canals evidence in males: one canal: 54.1%, two canals: 33.3%, three canals: 12.5%.

Incidence of canals in right premolar: one canal: 72.2%, two canals: 26.2%, three canals: 1%.

Canals in left premolar: one canal: 76.7%, two canals: 22.2% and three canals: 2%.

Canal configuration in single rooted first premolar: type I:74%, type II:10%, type III;6.5%, type V: 8.1%, and type VI were 1.1%.

Similarly in double rooted premolar: types I: 5.5%, type II: 22.2%, type IV: 16.6% and type V were 55.5%.

It can be concluded from the study that mandibular first premolar predominantly had single canal and type I configuration, but variations were found. Hence careful examination is essential.

[63]

Al-Shehri, S., et al. 2017

351

Maxillary

first molars

I‑CAT (Imaging Science International, Hatfield, PA, USA), Galileos (Sirona Dental Systems, Germany), Carestream CS 9300 (Carestream Health, Inc., Rochester, NY, USA).

0.3 mm

OnDemand3D software (Cybermed,

Seoul,Korea)

Vertucci’s classification

Retrospective data from database.

94% of the samples had three separated roots, and 6% fused roots which were higher in females (71.4%). DBRs and PRs were fused more commonly (4.8%) compared to other roots. It was frequent on the right side (61.9%). Occurrence of canals: 2 canals (3.7%), 3 canals (40.4%), 4 canals (55.6%) and 5 canals (0.3%). Type Icanal configuration was major in DBR (99.3%) and PR (100%) whereas MBR had higher frequency of type IV (55.6%).

According to this study majority of maxillary first molars had three roots and four canals. MBR had the fourth canal with prevalence of type IV.

[64]

Alamri, H.M., et al. 2020

351

maxillary second molars

Carestream CS 9300 (Carestream Dent LLC, Atlanta, G, USA)

180–300 μm

CS 3D imaging software (Carestream Dent LLC, Atlanta, G, USA)

Vertucci’s classification

Retrospective data from database.

Occurrence of roots: 1 root (0.3%), 2 roots (6.6%), 3 roots (92%) and 4 roots (1.1%). Two canals were significant in females while male patients had higher number of four canals, age and number of canals was inversely proportional.

This study concluded that, three and two rooted maxillary second molars are more common among Saudi population with higher tendency of three roots in males and two roots in females respectively.

[65]

Al-Habib, M. and M. Howait 2021

106

Maxillary first molars

iCAT scanner (Imaging Sciences International, Hatfield, PA, USA)

0.2 mm

Vision software (Imaging Science International, Hatfield, PA, USA).

Vertucci’s

classification

Retrospective data from database

Study revealed that 92 (86.8%) of maxillary first molars had MB2 canals, 61 (58%) of cases exhibited joining of MB and MB2canals at coronal 14 (23%), middle 17 (27%) and 31 (50%) apical third separately.

2.52 ± 0.76 mm was the mean inter orifice distance connecting two canals at the floor of pulp.

The study concluded that Saudi sub population had higher presence of MB2 canals in maxillary first molars which reduced as the canal reached apical third.

[66]

Al-Fouzan, K.S., et al. 2013

470

Maxillary first and second molar

Prospective study

It was evident that included maxillary 1st and 2nd molars had two canals in the mesial root.

33.1% of 1st molars end in one foramen which were confluent type, and two separate foramina were noted in 18.2%. Similarly, 2nd molar had 13.6% of one foramen for two canals and 6.2% of two foramens.

Study concluded the higher incidence of two canals in 1st maxillary molar and evidence of mesio palatal canal in the 1st and 2nd maxillary molars.

[67]

Mashyakhy, M., et al. 2022

624

Maxillary molars

3D Accuitomo 170, MORITA,

Japan

0.25 mm

Morita’s i‑Dixel 3D software

Vertucci’s classification

Retrospective data from database

All upper 1st molar had three separated roots, four canals were evident in 80% and three canals in 14.2% teeth.

Canal configuration in MB root was type I followed by type II, IV, III, V and type I was 100% in distobuccal and palatal roots.

99.3% of upper second molar had three separated roots and 2% were extra palatal root and 66.4% had four canals while 33.6% were three canals. Type I was 100% in palatal and distobuccal roots.

Maxillary molars had greater variations with higher frequency of four canals and type I configuration.

[68]

Mirza, M.B., et al. 2022

86

Maxillary molars

Carestream CS9300 (Carestream Dent

LLC, Atlanta, GA, USA) and Kavo OP3D Pro (KaVo

Imaging, Hatfield, PA, USA)

180-300 mm

Vertucci’s classification and new system of classification

Retrospective data from database

Three roots were noted in 100% max 1st molars while second molar had three roots in 95.5%, two roots (2.7%), four and one root in 0.75% and five roots in 0.3%. type I, II, III and IV vertucci’s type were seen in 1st molar and 2nd molar had type I, II and IV. MB root of max molars had type I, II, III and IV configuration.

Predominantly 1st maxillary molar had single root while 2nd molar had varied root numbers and both the molars displayed variations in terms of canals and their configuration. Both genders showed statistically significant difference.

[69]

Syed, G.A., et al. 2022

400

Maxillary molars

Vertucci’s classification

Retrospective data from database

Mesio buccal root of 1st and 2nd molar had type I (20.25%), type II (17.25%) and type III (17.25%). Right and left 2nd molars had higher frequency of type I and type II was major in first molar.

Study concluded higher presence of mesio buccal root with different configuration.

[70]

Aldosimani, M.A., et al. 2021

1377

Mandibular first and second molars

Planmeca Promax 3D Max digital imaging device (Planmeca, Helsinki, Finland)

0.1-0.4 mm

Planmeca

Romexis 5.2 (Planmeca, Helsinki, Finland).

Pomeranz et al. classification

Retrospective data from database.

Study discovered 12 (0.9%) mid-mesial canals from the population,

1.3% in first mandibular molar and 0.4% in second mandibular molar.

Confluent type of mid-mesial canal was more common (n = 10).

Study discovered that confluent type was more common MMC configuration then fin type, and independent type was not found

[71]

Alfawaz, H., et al. 2019

1210

Mandibular first and second molars

Planmeca Promax 3D max (Planmeca, Finland) and Cs 9300 (Carestream Health, USA)

200 and 300 μm

Romexis data viewer software (Romexis, Finland)

Fan et al. criteria

Retrospective data from database

C shaped canal system was present in one first molar (0.19%) whereas 62 (9.1%) in second molars (9.1%); majority of C shaped root anatomy was unilateral (53.85%).

Females had higher chances of c shaped root canal system than males, longitudinal grooves were more commonly present on the lingual surface of the root (58.1%)

The researcher discovered that Saudi population in the study had one C shaped canal in mandibular first molar (0.19%) and 62 in second molars (9.1%). C shaped anatomy was more frequent in females than males and unilateral C shapes canals were higher than bilateral. Occurrence of longitudinal groove was higher on the lingual surface of roots.

[72]

Alnassar, F., et al. 2022

145

Mandibular first and second molars

Planmeca ProMax 3D (PLANMECA, Roselle, IL, USA).

90–300 μm

Pomeranz et al. classification

Retrospective data from database

Study discovered that out of all the teeth only one extra MD canal was found in first mandibular molar (0.7%) which was confluent with the DL canal whereas mandibular second molar had no extra MD canal. Further the distance from MB and DB canal was 1.9 mm, MD and DL canal- 1.4 mm and from CEJ to MD canal was 3.1 mm respectively.

Study noted that the occurrence of MD canal was remarkably low in the studied population.

[73]

Mashyakhy, M., et al. 2019

174

Mandibular first molars

3D Accuitomo 170 (MORITA, Japan)

0.25 mm

Morita’s i‑Dixel 3D imaging software

Vertucci’s classification

Retrospective data from database.

Of the studied lower first molars, 97.1% were double rooted and 3 roots were in 2.9%.

With reference to canals:

Two canals- 1.7%,

Three canals-73% and

Four canasl-025.3%. In case of four canals, 90.9% extra canals were in distal root while distolingual root had 9.1%. Type I (77%) and type IV (64.9%) canal configuration was the most common in distal and mesial roots.

Canal configurations of mandibular first molar varied greatly in the studied Saudi population. Occurrence of three roots was low while three canals were common finding. Varying degree of bilateral symmetry was presented by number of canals and their configurations.

[74]

Mashyakhy, M., et al. 2021

657

First and second mandibular molars

3D Accuitomo 170 (MORITA, Japan)

0.25 mm

Morita’s i‑Dixel 3D imaging software

Vertucci’s classification

Retrospective data from database.

First mandibular molars had 2 roots- 95.4%, 3 canals-64.5% and type IV- 57.9% in mesial roots.

While second molars had 2 roots-89.6%, 3 canals-80.4% and type IV-39.4%. Either side of premolars showed identical anatomy.

It could be revealed from the study that majority of both the molars were double rooted and had three canals. Type IVwas major canal configuration in mesial canals of both the molars while type Iwas major in distal canal.

[75]

Al-Alawi, H., et al. 2020

741

Mandibular first molars

Promax 3D Max (Planmeca, Helsinki, Finland), Galileos Comfort (Sirona Dental Systems GmbH, Bensheim, Germany) and CS9300 (Carestream Dental LLC, Atlanta, GA, USA)

0.2-0.4 and 0.9 mm

Planmeca Romexis (version 5.2; Planmeca)

Carlsen and Alexandersen,

Song et al. classification

Retrospective data from database

Study revealed the presence of supernumerary roots (4.5%) among which 4.2% were on distolingual side and 0.35 were mesiobuccally. They usually had single canal occurring unilaterally. However bilateral occurrence was 1.3%.

Study concluded that the incidence of supernumerary root among the Saudi population was 4.5%.

[30]

Iqbal, A., et al. 2022

3420

Maxillary and mandibular anterior

3Dx SCANORA (Tuusula, Finland, Nahkelantie

160)

0.25 mm

On-demand 3D

version software 1.0.10.6388 (Daejeon, Korea, Yuseonggu)

Vertucci’s classification and new system of classification

Retrospective data from database

It was evident from the study that major type of configuration was type I and 1TN1 in maxillary anterior while predominant type was type I in lower anterior then type III and type IV. According to Ahmed’s classification majority was 1TN1 then 1TN1-2-1 and 1TN1-2.

Root canals of lower canine varied greatly in females then males.

Ethnicity and age had greater impact on the canal variation of upper laterals and lower anterior.

Lower anterior displayed broad canal variation and complexity in the root canal morphology. Differences in relation to root morphology was not greatly determined among genders except for the canine.

[76]

Mashyakhy, M 2019

794

Maxillary and mandibular canines

3D Accuitomo 170 (MORITA, Japan)

0.250 mm

Morita’s i-Dixel 3D imaging software

Vertucci’s classification

Retrospective data from database.

Mandibular canines were analyzed with

two roots- 2.7%, two canals- 9.3%,

type III- 6.1% and type V- 3.2% Vertucci’s classification. No two roots were found in maxillary canines and type IIIVertucci’s configuration was seen only in 1%. Further roots and canals presented bilateral symmetry in both the canines.

Study stated that both the sides of canals conveyed bilateral symmetry in mandibular canines.

[77]

Mirza, M.B 2022

1880

Maxillary and mandibular canines

Carestream CS9300 (Carestream Dent LLC, Atlanta, GA, USA)

180-300 mm

Not mentioned

New classification and Vertucci’s classification

Retrospective data from database.

One root was in 100% of maxillary canine while mandibular canine had 98.7% one root, 1.3% two roots, 97.48% type I,0.21% type II, 1.055 type III and 1.26% type V Vertucci’s classification. They represented significant difference in relation to canal morphology and number of roots as described by Vertucci but no such differences were observed by Ahmed at al.

Study concluded that mandibular canine indicated greater variation in relation to number of roots and morphology of canals however, one root and type Iwas predominant.

[78]

Almohaimede, A.A., et al. 2021

1328

Maxillary and mandibular canine

Planmeca ProMax 3D (PLANMECA, Roselle, IL, USA) and CS9300 3D digital

imaging system (Carestream, Rochester, NY)

75–600 μm

Planmeca Romexis Viewer software (Planmeca, Roselle IL)

Vertucci’s classification

Retrospective data from database

All the maxillary canines were single rooted (100%), one canal in 98.1% and two canals in 1.89%. However, mandibular canine had 97.11% one root, two roots (2.88%), one canal (90.05%) and 9.94% were two canals. Females had higher incidence of two roots than male. Type I configuration was common (94.9%) followed by type V (1.8%), type III (1.7%), type II (1.1%), type IV (0.4%) and type VII (0.2%).

Study concluded that incidence of one root, single canal and type I configuration was higher in maxillary and mandibular canine. Although mandibular canines had more variations compare to maxillary canine.

[79]

Alshammari, S.M., et al. 2023

286

Maxillary and mandibular premolar

SCANORA 3Dx (Nahkelantie 160, Tuusula Finland)

0.25 mm

Vertucci’s classification and Ahmed’s classification

Retrospective data from database

Incidence of one root: 73% (max right 2nd premolar), 70% (max left 2nd premolar), 53% (max right 1st premolar), 38% (max left 1st premolar).

Evidence of two roots: 62% (max left premolars), 47% (max right premolars). Whereas mandibular premolars frequently had single root.

Frequency of two canals: 82% (max left 1st premolar), 76% (max left 2nd premolar), 74% (max right 1st premolar), 58% (max right 2nd premolar). 18–29% (mand premolars).

Max premolar had vertucci’s type IV, type I in mand premolars however 2% of type III was noted in mand left 1st premolar. (2 FP B1 P1) was predominant in ma 1st premolar (73% and 81%) then (1 FP 2) 19%.

Among the investigated population frequency of second canal was less in maxillary and mandibular premolars compared to one root and single canal.

[80]

Boreak, N.M., et al. 2022

1666

Maxillary and mandibular premolars

3D Accuitomo 170 (MORITA Japan)

0.25 mm

Morita’s i‑Dixel 3D

Retrospective data from database

Of the studies premolars, majority of first and second right and left maxillary premolars had two canals (93%, 95%,57%,43%) while max right 2nd premolar had higher number of one canal compared to other. All the mandibular premolars had single root and canal. Circular cross-sectional shape was major among 1st and 2nd max premolars at coronal, middle and apical area than flattened and oval type with exception of right max 2nd premolar. Similarly common cross section in coronal area of 1st and second mand premolar was oval flattened and circular.

Study focused on the cross-sectional canal shape of maxillary and mandibular premolar indicating that circular shape was prominent in the apical area while variations were noted in the coronal and middle area.

[81]

Iqbal, A., et al. 2022

1443

Maxillary and mandibular premolars

SCANORA 3D CBCT unit (Soredex Inc., Tusula, Finland)

On Demand 3D software

Vertucci’s classification

Retrospective data from database

Maxillary 1st premolar had two roots (52.6%) then one root (26.5%), two fused roots in 19.3%, two separated roots in 0.8% and three roots were 0.5%. Type I was major followed by others. Likewise single root with one canal and type I was common finding in maxillary 2nd premolar.

Mandibular 1st and 2nd premolar predominantly had one root and single canal with type I and absence of three roots.

It was concluded from the study that wide variations of root canal morphology were noted among upper and lower premolars.

[82]

Alhujhuj, R.R., et al. 2022

123

Maxillary and mandibular first molars

I-CAT Vision QTM (Imaging Sciences International Hatfield, PA, USA. Version 1.9.3.14

0.25 mm

BlueSkyPlan (Version 4.7.55, GmbH, Langenhagen, Germany)

Vertucci’s classification

Retrospective data from database

Findings of the study are as follows:

Right maxillary 1st molar: three roots (90.2%), four roots (9.8%), three canals (78.9%), four canals (21.1%), MB root had type I (87%), type IV (9.8%), type II (3.3%). Palatal root had 99.2% type I. MB root of left molar: 84.6% (type I), 9.8% (type IV), 5.7% (type II).

Left mandibular first molar: three roots (85.4%), four roots (12.2%), three canals (73.2%), four canals (25.2%), type I (100%).

Right mandibular first molar: three roots (85.4%), four roots (13.0%), two roots (1.6%). Three canals (74.0%), four canals (25.2%) and two canals (0.8%). Type I configuration was 100%.

Study concluded that the majority of studied Saudi population had three roots and three canals along with type I.

[83]

Mashyakhy, M., et al. 2020

1433

Mandibular premolars and molars

3D Accuitomo 170 (MORITA, Japan)

0.25 mm

Morita’s i‑Dixel 3D imaging software

Retrospective data from database.

Incidence of C-shaped canals was 1.5% in lower first premolar, second premolar-0.80%, second molars-7.9% and absent in first molars. Different types of C-shaped canals were found in both molars and premolars while C2 was prominent in premolars and C3 was in second molars. External longitudinal grooves were dominant on mesiolingual surface of premolars and lingually in molars. Increased incidence of C-shaped canals was seen in second molars among females but premolars had no difference.

Occurrence of C-shaped canals was higher in second mandibular molars but less in lower premolars. There was no significant difference in relation to gender and sides.

[84]

Mashyakhy, M. and A.S. Abu-Melha, 2021

5223

Permanent maxillary and mandibular teeth

3D Accuitomo 170 CBCT unit (J Morita, Kyoto, Japan)

0.25 mm

i-Dixel 3D imaging suite

Vertucci’s classification

Retrospective data from database.

Roots displayed 100% bilateral symmetry in the maxillary arch except first premolar while higher variations were seen in lower arch except second premolar. Canals and their configuration of upper central and lateral incisors had 100% bilateral symmetry while asymmetry was noticed among second molars.

Maxillary arch was more symmetrical than the mandibular arch. Evidence of bilateral symmetry was highest in terms of roots than canals and the least was presented by canal configuration.

[85]

Mashyakhy, M. Mashyakhy, M., et al. and G. Gambarini 2019

5254

Permanent maxillary and mandibular teeth

3D Accuitomo 170 (MORITA, Japan)

0.25 mm

Morita’s i‑Dixel 3D imaging software

Vertucci’s classification

Retrospective data from database

No remarkable difference was noted among males and females in terms of number of roots, while significant difference was shown by canals of upper teeth among both the genders. Canal configuration was statistically significant in upper roots between males and females. Canal configuration of anterior and premolar of lower arch were significantly different but no difference was found in mesial roots of both the molars however, it was opposite in case of distal roots.

Study concluded that number of roots in males and females of Saudi population were not significantly different but the canals and their configuration had differences in upper and lower teeth between both the genders