|Year : 2021 | Volume
| Issue : 3 | Page : 182-186
Tomographic analysis of the apical anatomy of mandibular first and second premolars in central India population
Ruchi Verma, Suparna Ganguly Saha, Arati Chaudhary, Anuj Bharadwaj, Shrija Paradkar, Sheetal Khandelwal
Department of Conservative Dentistry and Endodontics, College of Dental Science and Hospital, Madhya Pradesh Medical Science University, Indore, Madhya Pradesh, India
|Date of Submission||28-Mar-2021|
|Date of Decision||10-May-2021|
|Date of Acceptance||07-Sep-2021|
|Date of Web Publication||30-Sep-2021|
Dr. Ruchi Verma
I 450 LIG Colony, Indore, Madhya Pradesh
Source of Support: None, Conflict of Interest: None
Aim: Aim of the present study was to evaluate the distance of the apical foramen in relation to the anatomical apex of mandibular premolars by Cone Beam Computed Tomography (CBCT) in a selected population of Central India.
Objectives: To evaluate and compare the distance between the apical foramen and the anatomic apex of the mandibular first and second premolars of both the sides of mandible and in both the genders in a selected population of Central India.
Material and Methods: In this cross-sectional study, screening of total 250 CBCT scans of patients with a minimum age of 20 years, were evaluated and only 170 CBCT images (88 males and 82 females) were considered for the study based on the inclusion criteria. Furthermore, scans were observed in axial, sagittal and coronal planes.
Results: Average (±SD) distance from apical foramen to the anatomic apex of first and second premolars in male was 0.61 - 0.62 mm and for females was 0.58 - 0.60 mm. No statistical significant difference was found between right and left quadrant and in males and females.
Conclusion: The study demonstrated that minimum 1mm of distance from the anatomic apex in mandibular premolars could be appropriate for root canal therapy.
Keywords: Tooth apex, premolars, CBCT, anatomical root apex, apical foramen
|How to cite this article:|
Verma R, Saha SG, Chaudhary A, Bharadwaj A, Paradkar S, Khandelwal S. Tomographic analysis of the apical anatomy of mandibular first and second premolars in central India population. Endodontology 2021;33:182-6
|How to cite this URL:|
Verma R, Saha SG, Chaudhary A, Bharadwaj A, Paradkar S, Khandelwal S. Tomographic analysis of the apical anatomy of mandibular first and second premolars in central India population. Endodontology [serial online] 2021 [cited 2022 May 22];33:182-6. Available from: https://www.endodontologyonweb.org/text.asp?2021/33/3/182/327273
| Introduction|| |
A successful endodontic treatment depends on the knowledge of internal anatomy of root canals, which plays an important role in ensuring thorough debridement and three-dimensional obturation of the root canal system even in the most complex apical third areas. Several studies reported that the prevalence of accessory canals and isthmuses is high in the apical 2–5 mm of the root., Complete debridement of these regions through mechanical instrumentation is impractical, and necrotic tissue remnants and microorganisms in the apical portion affect the posttreatment outcome. Precise knowledge of the morphology of apical foramen (AF) and internal anatomy of the roots is essential in the success of endodontic treatment. The main anatomic and histological references for determining the apical limit of root canal therapy are the cementodentinal junction (CDJ) and the apical constriction (AC). As it is difficult to determine the exact location of the CDJ and AC by radiograph, hence, the AF is considered as a reference point in the present study.
Mandibular premolars exhibit high degree of variation in their root canal anatomy. This variation is most prevalent in mandibular first premolars making it as endodontist's enigma. Premolars revealed high heterogeneity based on factors such as age, sex, and ethnicity.,
Various studies have examined root canal morphologies using various methods such as direct visual technique, light microscopy (anatomical studies), conventional radiography, clearing technique using injection of methylene blue,, black India ink, or Chinese ink, metal or plastic casting,, in vitro endodontic access cavity with radiography and instruments,, radiopaque gel infusion, digital radiography techniques, stereomicroscopy, scanning electron microscopy, tactile sensation, digital roentgenography, electronic apex locators, and cone-beam computed tomography (CBCT) scanning.,,
Drawbacks of radiography include technique sensitivity, subjectivity, and inaccuracy related to superimposition of anatomical structures producing a two-dimensional representation of a three-dimensional object.
To overcome this, CBCT was used in the present study which provides a practical tool for noninvasive and three-dimensional reconstructive imaging, a validated tool used to explore root canal morphology. CBCT uses less radiation and provides higher resolution than conventional CT. In addition, the superior image quality and the ability to perform three-dimensional evaluation on axial, sagittal, and coronal cross sections along with the three-dimensional reconstructed images can help to clearly determine the location of the structures.
Since the anatomy and morphology of the root canals may be different in different races, therefore, a study was conducted to evaluate the distance between the AF and the anatomic apex of mandibular first and second premolars on both the sides of mandible.
| Materials and Methods|| |
The cross-sectional study was conducted on CBCT scans which were already available at Sampurna Diagnostic Center, Indore. All the data were provided by the diagnostic center keeping the patients identity confidential. Scans were taken for various diagnostic purposes such as diagnosis of radiolucent lesions, treatment planning for implant placement, assessment of relationships of teeth location with clinically important anatomical structures, and maxillofacial surgery.
In this comparative study, screening of total 250 CBCT scans of patients with a minimum age of 20 years was evaluated, and only 170 CBCT images (88 males and 82 females) were considered for the study based on the inclusion criteria, i.e. fully erupted roots of mandibular premolars with mature apices, nonexistence of any previous maxillofacial trauma, no surgery or orthodontic treatment, complete recognizable AFs, absence of the apical resorption, nonendodontically treated teeth, and samples belonging to central India population.
Both the right and left side of the mandible were evaluated with the CBCT scans. The scans were studied using NNT viewer software program (NNT software corporation, Yokohama, Japan). CBCT projections were analyzed in different planes (sagittal, axial, and coronal). A line was drawn from the AF to the anatomic apex using 0.5-mm thick sections, and this distance was measured using a measuring tool. Furthermore, distance from AF to the anatomic apex was observed in axial, sagittal, and coronal planes. All images were observed by the student, radiologist, and an endodontist. Data were analyzed using SPSS (Statistical Package for the Social Sciences) v. 20 software (SPSS version 20 Armounk, NY : IBM Corp), and statistical analysis was done using of Kolmogorov–Smirnov test, unpaired “t” and paired “t” tests.
| Results|| |
Average (±standard deviation [SD]) distance from AF to the anatomic apex of first and second premolars in male was 0.61–0.62 mm with ± SD of 0.142 and P value 0.54 in right and left quadrant and for females was 0.58–0.60 mm with ± SD of 0.129 and P = 0.22 for both right and left quadrant.
According to t-test, no statistical significant difference was found in the distance between the AF and the anatomic apex of first and second premolars in both right and left quadrants (P = 0.857). Comparison of mean distance between the apical foramen and anatomic apex of first and second premolars between right and left side in both males and females has been shown in [Table 1], [Table 2], [Table 3], [Table 4].
|Table 1: Comparison of mean distance between apical foramen and anatomic apex of right first premolar and right second premolar between males and females|
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|Table 2: Comparison of mean distance between apical foramen and anatomic apex of left first premolar and left second premolar between males and females|
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|Table 3: Comparison of mean distance between apical foramen and anatomic apex of first premolar between right and left side of males and females|
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|Table 4: Comparison of mean distance between apical foramen and anatomic apex of second premolar between right and left side of males and females|
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| Discussion|| |
The apical one-third of root canals is a strategic region in terms of working length determination and interaction with the surrounding living tissues, and thus, it can directly affect the periapical healing. In this respect, the important anatomical landmarks are the AC, AF, radiographic apex, and the anatomical apex. Over the period of time with advanced age and cementum deposition around the area of the apex, AF is deviated toward various directions. In many cases, the AF deviates buccally or lingually to the root apex, which can be superimposed on the root structure and lead to erroneous working length determination and may cause treatment failure.
In this cross-sectional CBCT study, average distance from AF to the anatomic apex of first and second premolars in male and female was 0.61–0.62 mm with ± SD of 0.142 and P = 0.54 and 0.58–0.60 mm with ± SD of 0.129 and P value 0.22, respectively. The results of the measurement of the apex to foramen distances in this study were in close agreement with previous findings. Burch and Hulen found the AF distance to be 0.59 mm in a study of all tooth types, and study conducted by Arora and Tewari reported the distance between the AF found to be in a range of 0.052–2.91 mm. Similar study was conducted by Naseri et al. revealed that the mean distance between AF was found to be in the range of 0.3–0.7 mm which is in accordance with the values calculated in the present study. Kuttler stated that the AF distances in groups of teeth of young and old patients were 0.48 mm and 0.6 mm, respectively. In another study by Martos et al. which was conducted by using a stereomicroscope on mandibular molars of a Brazilian population, mean distance from apex to AF was 0.80 (±0.54) mm. Akhlaghi et al. in an ex vivo study in a local Iranian population using India ink on mandibular second molars were showed, and mean (±SD) distance from the apex of the AF was 0.30–0.47mm. India ink was used in this study which makes the evaluation method different than the present study. Green reported the distance to be 0.43 mm in posterior teeth and 0.29 mm in anterior teeth. Study conducted by Cheung et al. indicated that the average distance of AF from the anatomic apex at the C-shaped mandibular second molars in a Chinese population is 0.79–0.89 mm by using micro-CT. These slight variations are to some degree due to the varying methods used to measure the distance as well as to the different reference points that were probably used. Furthermore, the other reason for this difference can be owing to differences in various population.
In the present study, no significant difference was found between the right and the left side of mandible which is in accordance with the study conducted by Sadri et al.
However, the mean distance between the AF to the anatomic apex of the first and the second premolar is found to be more in males with the value of 0.62 mm with the standard deviation of ± 0.139 when compared to females with the mean value of 0.58 mm with the standard deviation of ± 0.110. The results of present study are in contrast to the study conducted by Awawdeh et al. They revealed that mean distance between AF is found to be more in females when compared to males.
However, variation in the distance of the AF thus shows racial predilection. The precise assessment of the AF distance proved to be a very helpful tool in clinical dental practice and has to be taken into consideration during root canal procedure. Thus, obtained results could be very useful for many clinicians. The unpredictable nature of the position of the AF with respect to the anatomic apex further strengthens the need of using electronic apex locators rather than relying on radiographs for canal length determination. These findings also support the current practice of cutting 3 mm of the root apex during surgical procedures to ensure the removal of most of the unprepared and unfilled canals. Therefore, further studies are needed to corroborate the findings of the present study in the clinical situation.
| Conclusion|| |
This study demonstrated that the distance between the AF and the anatomic apex in the mandibular premolars in central India population was approximately 1 mm, and therefore, the extent of obturation should be 1 mm short of the radiographic apex and the root canal procedure should be terminated at this point.
However, the limitation of the present study was that it was conducted in limited population in central India region. Hence, further studies need to be conducted in different geographical location in India, the cumulative results of which must be evaluated to ascertain the exact location of the AF in the Indian population.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4]