|Year : 2021 | Volume
| Issue : 3 | Page : 178-181
Morphological variability of permanent mandibular first premolar teeth in Manipuri population: An In vitro study
Takhellambam Devi Premlata1, Shamurailatpam Priyadarshini1, Amandeep Kaur1, BS Deepak1, Nandita Kshetrimayum2, Ng Sanjeeta3
1 Department of Conservative Dentistry and Endodontics, Dental College, Regional Institute of Medical Sciences, Imphal, Manipur, India
2 Department of Public Health Dentistry, Dental College, Regional Institute of Medical Sciences, Imphal, Manipur, India
3 Department of Oral Pathology and Microbiology, Dental College, Regional Institute of Medical Sciences, Imphal, Manipur, India
|Date of Submission||01-Sep-2020|
|Date of Acceptance||16-Jan-2021|
|Date of Web Publication||12-Jul-2021|
Takhellambam Devi Premlata
Department of Conservative Dentistry and Endodontics, Dental College, Regional Institute of Medical Sciences, Imphal - 795 004, Manipur
Source of Support: None, Conflict of Interest: None
Aim: To investigate anatomical and morphological variability of permanent mandibular first premolar teeth in the population of Manipur state of Indian subcontinent. Materials and Methods: Four hundred and eighty teeth from a pool of Manipuri population were studied for anatomical and morphological variability using staining and clearing technique. All samples were evaluated for the number of roots, root canals, root canal configuration, presence of lateral canals, intercanal communications, and apical deltas. Results: Single root with one canal was present in 81.25% (390/480) and single root with two canals in 18.75% (90/480) of samples. Root canal configuration according to Vertucci's classification was as follows: Type I (43.7%) followed by Type V (25%), Type VI (12.5%), and Type II, III, and VII (6.25%). Intercanal communications in the apical third were 12.5% (60/480) and 6.25% (30/480) in the middle third of the root. Occurrence of lateral canals in the apical third was 18.75% (90/480). Apical delta was found in 37.75% (180/480) of samples. Conclusion: The results of this study highlight the variability patterns of mandibular first premolar tooth existent in the population of the state of Manipur. Single-rooted teeth are most common with predominantly Vertucci's Type I root canal configuration and significant presence of lateral canals and apical ramifications. Clinical Significance: Sound knowledge of anatomy of the root canal and possible variations can contribute to a successful treatment outcome.
Keywords: Canal staining and clearing, mandibular first premolar, Manipuri population, root canal configuration, Vertucci's classification
|How to cite this article:|
Premlata TD, Priyadarshini S, Kaur A, Deepak B S, Kshetrimayum N, Sanjeeta N. Morphological variability of permanent mandibular first premolar teeth in Manipuri population: An In vitro study. Indian J Dent Sci 2021;13:178-81
|How to cite this URL:|
Premlata TD, Priyadarshini S, Kaur A, Deepak B S, Kshetrimayum N, Sanjeeta N. Morphological variability of permanent mandibular first premolar teeth in Manipuri population: An In vitro study. Indian J Dent Sci [serial online] 2021 [cited 2021 Sep 20];13:178-81. Available from: http://www.ijds.in/text.asp?2021/13/3/178/321173
| Introduction|| |
Variation is the only constant when it comes to root canal anatomy. Knowledge and understanding of the complexities of root canal system is imperative for proper cleaning, shaping, and success of nonsurgical endodontic therapy. Morphological variability has been reported among different races and among the same race previously. The northeastern state of Manipur is inhabited by various ethnic groups where Meiteis, Kukis, and Nagas are the predominant tribes. Published data of this trend are lacking with respect to Manipuri population. Hence, the present study was undertaken with the aim of collecting information about the variability patterns seen in mandibular first premolar tooth in the people residing in Manipur.
| Materials and Methods|| |
A total of four hundred and eighty permanent mandibular first premolar teeth were collected randomly from various government hospitals and dental clinics located in Manipur. These teeth had been extracted as a part of orthodontic or periodontal treatment plan. The identification of each tooth was confirmed using Woelfel criteria. The teeth with mature root apex were included irrespective of gender and age. Immature teeth with open apex and teeth demonstrating signs of external root resorption or fracture were excluded from the study. The teeth were gently cleaned and adherent calculus, debris, and soft tissues were removed. To remove the organic debris, the samples were treated with 5.25% sodium hypochlorite solution for 30 min. Thereafter, the samples were stored in 10% formaldehyde until further use. Access cavity was prepared with a number 2 round bur under water coolant. Coronal pulp tissue was extirpated and DG-16 endodontic explorer was used to identify the canal orifices on the floor of the pulp chamber (Hu Freiday, Chicago, IL, USA). Exploration of the developmental groves was done for locating extra canals.
The samples were further stored in 5.25% sodium hypochlorite for a period of 48 h to remove remnants of pulp tissue. They were rinsed with running water for 4 h to eliminate sodium hypochlorite. Thereafter, the samples were immersed in 5% nitric acid solution for 5 days for decalcification. This solution was changed every day and agitated thrice daily. After demineralization was complete, dehydration was carried out by keeping the samples in 70%, 80%, and 95% ethyl alcohol for 30 min each. Oil-based dye, India Ink which easily flows into the minute details was injected into the root canals with a 27G needle. Excess was removed with a gauge soaked in alcohol. The dehydrated samples were then placed in methyl salicylate for clearing. Complete transparency was achieved by the 3rd day. This allowed enhanced appreciation and three-dimensional (3D) view of the root canal anatomy. The samples were subjected to examination under a dissecting microscope at ×10 magnification.
| Results|| |
The samples after decalcification, dehydration, and clearing were examined for various morphological characteristics. First, the samples were studied for the number and type of root canals present. Single root with single canal was present in 81.25% (390/480), whereas single root with two canals was seen in 18.75% (90/480) of samples [Table 1]. The predominant root canal configuration according to Vertucci's classification was Type I (43.7%), followed by Type V (25%), Type VI (12.5%), and Type II, III, and VII (6.25%) [Figure 1]. Type IV and Type VIII configuration was not evident in this population. Type I, V, and VI were predominantly seen in the males, whereas Type II, III, and VII were present in the females [Table 2]. This gender-based difference was, however, not statistically significant (P = 0.8565). The presence and location of intercanal communications was also studied. They were absent in the coronal third. However, 12.5% (60/480) were present in the apical third and 6.25% (30/480) in the middle third of the root [Table 3]. A slight female predilection was also noticed, which was not statistically significant (P = 0.903). The lateral canals were located in 18.75% (90/480) of the samples in the apical third with no occurrence in the coronal and middle third of the root [Table 4]. Apical delta was found in 37.75% (180/480) of samples [Table 5] and [Figure 2]. Chi-square test was used to analyze the data collected. SPSS 17.0 program (SPSS Inc., Chicago, USA) software was used.
|Table 1: Number of roots and root canals in permanent mandibular first premolar (n=480)|
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|Table 2: Root canal configurations of permanent mandibular first premolar (n=480)|
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|Table 3: Distribution of intercanal communications in permanent mandibular first premolar (n=480)|
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|Table 4: Presence of lateral canals in roots of permanent mandibular first premolar (n=480)|
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|Table 5: Presence of apical delta in permanent mandibular first premolar (n=480)|
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|Figure 1: (a) Vertucci's Type I root canal configuration. (b) Vertucci's Type II root canal configuration. (c) Vertucci's Type V root canal configuration|
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| Discussion|| |
The mandibular first premolar tooth is considered as an enigma because of its extreme morphological variations, high flare-up, and failure rate. Therefore, it becomes imperative to understand and recognize the anatomical complexities of this bicuspid tooth. Deviation from the normal anatomy in mandibular first premolars has been reported to be linked with ethnic background and genetic makeup of individuals. Additional canals in mandibular first premolars have been reported in Chinese, Turkish, and Kuwaiti populations. Turner syndrome has also been correlated with the occurrence of extra roots in these teeth. Since no previous data were available on the root canal morphology of mandibular first premolar in a Manipuri population, the present study was done to collect a baseline data for the same. Root canal anatomy can be studied by different methods including radiographs, cone-beam computed tomography,[ 3] sectioning and macroscopic examination, or 3D reconstruction. Decalcification, staining, and clearing technique was used since it is simple, cost-effective and enables direct visualization under the microscope. For in vitro studies, it provides significant 3D information about the morphology of root canal systems without using negotiating instruments, thereby preserving the original structure and is often considered as a gold standard.
In the present study, single root was observed in all the samples. 81.25% demonstrated single root with single canal, out of which 51.5% were male and 48.5% female. Double canals in single root represented 18.75% population, in which males were 42.2% and females were 57.7%. This is in line with data in the literature reporting prevalence of single canal in single root as 69.3%–86% and two canals in one root as 14%-25.5%.,, Type I Vertucci's root canal configuration (one canal from pulp chamber to the apex) was the most common (43.75%). Reported incidence of Type I is 70%, 72%, 67.2% to 86.3%, and 67.39% by Vertucci, Velmurugan and Sandhya, and Jain and Bahuguna, respectively. Type II, Type III, and Type VII in the present study were found in 6.25% samples with a slight female predilection. Type II canal configuration (two canals joining into a single canal near the apex) has reported incidence of 0%, 6%, and 7.97% by Vertucci, Velmurugan et al., and Jain et al., respectively. Type III (single canal dividing into double and exiting as one canal) was observed in 4% by Vertucci, 3% by Velmurugan and Sandhya, and 3.62% by Jain and Bahuguna. The reported incidence of Type IV (two separate canals) in previous studies was 1.5%, 10%, and 2.89%, whereas it was not encountered in any sample in the current study. Type V and Type VII were found more in the male samples in the current study. The incidence of Type V (single canal bifurcating into two) was 25% in the present study, whereas it has been depicted in 24%, 8%, and 17.39% in earlier studies. Type VI canals (two separate canals joining to form one canal and exiting as two close to the apex) were observed in 12.5% in this study and 0.72% in another study. Type VIII configuration (three separate canals) was not found in the current study. These differences can be attributed to different populations studied by various researchers. Vertucci et al. studied the Caucasian population, Velmurugan et al. South Indian population, and Jain et al. Gujarati population.
Intercanal communications in the form of isthmus are invariably present when a root contains two or more root canals. These ribbon-shaped areas are of clinical importance since they are challenging to debride and act as potential sources of bacterial reservoir. Isthmi in the present study were observed in 18.75% of samples, which is consistent with the findings of Caliskan et al. Lateral canals in the current study were found in 53.33% of females and 46.66% of males in the apical third. Apical delta occurred in 56% of females and 43.8% of males. Although no statistically significant gender-based conclusion was drawn from this study in terms of morphological variations in the mandibular first premolar teeth, this was the first study to provide information about deviations present in males and females among the Manipuri population.
| Conclusion|| |
The results of this study depict divergence in morphology of mandibular first premolars in Manipuri population. This observation coupled with radiographic interpretation of the internal anatomy of the tooth can be of immense value when rendering endodontic therapy in a clinical setup. Studies with larger sample sizes should be conducted in the future to derive a more accurate description about the complexity of pulp space anatomy in these teeth.
Since the study is in-vitro study done on teeth extracted for various other reasons, no ethical clearance was obtained.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]