|Year : 2020 | Volume
| Issue : 2 | Page : 135-139
Approach for assessment of inferior alveolar canal to roots of mandibular second molar and mandibular cortex for ramadi city individuals, Iraq: A retrospective radiographic study
Mohanad A Hammad
Department of Oral Diagnosis-Dental Radiology, College of Dentistry, AL-Anbar university, AL-Anbar, Iraq
|Date of Submission||19-Nov-2018|
|Date of Acceptance||23-Oct-2019|
|Date of Web Publication||28-Mar-2020|
Dr. Mohanad A Hammad
Assistant Teacher, Department of Oral Diagnosis-Dental Radiology, College of Dentistry, AL-Anbar university.
Source of Support: None, Conflict of Interest: None
Aims: To investigate the distances between inferior alveolar canal (IAC) to both mesial and distal roots of mandibular second molar (M2) and inferior mandibular cortex. Materials and Methods: This retrospective study was carried out on 110 patients (50 women and 60 men) aged between 20 and 50 years. Each patient took one panoramic image and one digital intraoral image for the right side at second molar area. Patients were evaluated by gender and age (coterie I = 54 and coterie II = 56). Data were analyzed by using the Statistical Package for the Social Sciences Statistics software, version 22.0 (IBM, Chicago, Illinois), and the mean values were compared using the compare means test. Results: The results showed no significant differences at P > 0.05 between men and women in the distances of M2 roots and mandibular cortex to IAC by both digital techniques. However, the roots of M2 of women (2.7 and 1.8 mm by digital panoramic, 2.6 and 2 mm by digital intraoral image) and of those aged less than 35 years (3.1 and 2.45 mm by digital panoramic, 3.1 and 2.56 mm by digital intraoral image) were near to the IAC. Conclusion: Preoperative investigations to know the degree of vicinity of roots of M2 and lower jaw canal by using of digital radiographic imaging (intraoral and panoramic) depending on their properties (image enhancement, measuring tools, and updating data) have high values to avoid a complications such as distress and numbness after dental procedures by direct damage or pushed toxic dental materials in this tunnel.
Keywords: Digital, Inferior Alveolar Canal, Mandibular Second Molar, Panoramic
|How to cite this article:|
Hammad MA. Approach for assessment of inferior alveolar canal to roots of mandibular second molar and mandibular cortex for ramadi city individuals, Iraq: A retrospective radiographic study. J Int Oral Health 2020;12:135-9
|How to cite this URL:|
Hammad MA. Approach for assessment of inferior alveolar canal to roots of mandibular second molar and mandibular cortex for ramadi city individuals, Iraq: A retrospective radiographic study. J Int Oral Health [serial online] 2020 [cited 2020 May 28];12:135-9. Available from: http://www.jioh.org/text.asp?2020/12/2/135/281495
| Introduction|| |
In the inferior alveolar canal (IAC) the neurovascular bundle of the same name, this canal tends to be curved down from mandibular foramen to body of mandible. It is located medially to apices of molar teeth and buccal to bicuspids teeth to the area near mental foramen. The IAC ends into a hole called mental foramen from which the branch of nerve and the blood vessels exited are called as mental nerve and vessels. The proximity of mandibular molar teeth to IAC mimics the predisposing factors to damage the IAC through the extraction of lower molar teeth, endodontic therapy, and dental implant surgical procedure. The impairment of IAC in extraction and implant occurs because of direct pressure on inferior alveolar nerve, whereas in root canal therapy, the neurotoxicity of endodontic material, which may be expelled from root, and contact with the nerve of IAC lead to pain and numbness of the inferior alveolar nerve. Especially toxicity when endodontic intracanal calcium hydroxide had pushed to IAC. Traditionally, the mandibular second molars (M2) emerge in the mouth of 12-year-old of human and the roots may be shorter than those of the first molars and may be tilted lingually. In mandible bone, the first molar root apices were described as close to IAC but the apices of roots of the second molar were the closest than the first molar so it can cause damage to IAC nerve more than other posterior teeth. Conventional intraoral technique and digital techniques (intraoral, panoramic, and three-sided radiologic techniques) can give information about the relation between teeth and IAC. A panoramic radiography, which gives a two-dimensional depiction, is commonly performed before any dental procedure in molar area. A panoramic radiography is indicated to be the most chosen method for radiology evaluation among many dentists, only due to its low price and low-radiation load.
In the Ramadi city, Anbar Governorate, Iraq, many dental patients were complaining from troubles and complications of IAC after some dental operations even with perfect work such as root canal treatment as streaming of sealer or intracanal irrigants solutions and their damaging effects into IAC.
The aim of this study was to evaluate the vicinity of mesial and distal roots of M2 and mandibular cortex to IAC in order to learn the most risky distances to IAC during different dental operations (surgical or conservative) to avoid direct damage of surgical procedure or dental materials of endodontics on vital contents of IAC, which is mostly elevated with shortest distance of second molar roots to IAC. This study depending on sex variations and agecoterie’s Variables and by using dental digital technique (intraoral and panoramic), which are two-dimensional images but they can have a length tool scale electronically.
| Materials and Methods|| |
A retrospective study was acheived during first five months of 2018 in the Ramadi city, Anbar Governorate, Iraq, of (220) images(panoramic and intraoral) were achieved in Ramadi center for dental radiation for samples 110 patients had been as part of Ramadi city population size (900,000 individuals, confidence level 90%, and error margin 10%), i.e. 100 sample. A 110 digital panoramic and 110 for digital intraoral radiographs concentrated at right side in second molar area distributed between 50 females and 60 males with age range between (20–50) year mean age (35) year. This study was carried out under the agreement of ethics approval committee of University of Anbar, Iraq (Protocol no. 22 IN 5/11/2017).
The participants were subdivided by sex and age coterie I (20–35 years, n = 54) and coterie II (35–50 years, n = 56). The inclusion criteria of the study were the presence of M2 at right side, images with less errors (proper machine settings according to patient mode and area of interest, perfect patient position in the focal trough of panoramic machine to obtain proper geometry of object image), proper visual view, separated M2 roots, and clearance of both mandibular canal borders and inferior cortex. The exclusion criteria of the study were incomplete second molar root formation, extraction or loss of M2, periapical changes, tumors, and systemic diseases that can affect the bone consistency of mandible inferior cortex.
Digital panoramic radiography was performed with CS8100 digital panoramic system (Carestream Dental, Marne-la-Vallee, France). The exposure settings were 80 kVp and 8 mA, and exposure time was 10.7s. The gray scale and bits for the panoramic machine were 4096–12 bits. Panoramic images were analyzed by CS Imaging software, version 7.0 (SDK Modules, Trophy, France). A digital intraoral radiograph (parallel technique using Dentsply Rinn XCP holder, Elgin, U.S.A) was achieved with Kodak 2100 intraoral X-ray machine system (Carestream Dental, Rochester, New York). The exposure settings were 60 kVp and 6 mA, and exposure time was 0.32s. A Kodak 5200 RVG sensor (Carestream Dental) was used as an image receptor for intraoral technique.
Data measurement parameters
This study included all M2 roots that were not superimposed with IAC in all groups. Genders (males and females) and age groups (coterie I 20–35 year, n = 54), and (coterie II 35–50 year, n = 56).
The distances between the roots (mesial and distal) of M2 and the superior bone lamella of IAC and the distances between the inferior mandibular cortex and inferior bone lamella of IAC perpendicular to occlusal plane were calculated in millimeters by Carestream imaging digital imaging software, version 7.0 [Figure 1]A and B, with respect to sex and age coterie.
|Figure 1: Digital panoramic using measurement tool to calculate the distance between (A) distal root and IAC, and (B) inferior mandibular cortex and IAC|
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The statistical analysis was performed using the Statistical Package for the Social Sciences software],[ version 22.0 (IBM],[ Chicago],[ Illinois)],[ and the mean values were compared using compare means test.
| Results|| |
A total of 110 patients were subjected without missing any data or conditions as they were selected according to the inclusion criteria. The mesial root of M2 in men appeared far away than that in women because the distance to superior bone lamella of IAC in men was mean = 3.1 mm; standard deviation (SD) = 2.8 mm],[ whereas for women],[ itwas mean = 2.7 mm; SD = 2 mm. No significant differences were found in the distance at P > 0.05. For the distal root of M2],[ the women showed shorter distance to superior bone lamella of IAC (mean = 1.8 mm; SD = 1 mm) than the men (mean = 2.5 mm; SD = 1.9 mm). No significant differences were found in the distance at P > 0.05. The inferior mandibular cortex appeared nearest to inferior bone lamella of IAC in women (mean = 6.89 mm; SD = 1.55 mm)],[ whereas in men],[ it appeared far away from inferior bone lamella of IAC (7.30 mm; SD = 2.05 mm). No significant differences were found in distance at P > 0.05 [Table 1].
|Table 1: Sex variations for distance between mandibular second molar roots and mandibular cortex to inferior alveolar canal (in millimeters) by digital panoramic|
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IAC appeared to be safe from mesial roots of M2 in men when the distance to superior bone lamella of IAC was mean = 3 mm; SD = 2.6 mm than that in women who had distance of mean = 2.6 mm; SD = 1.87 mm. No significant differences were found in the distance at P > 0.05. The same situation was observed for distal root of M2 in men with mean = 2.85 mm; SD = 1.89 mm],[ whereas in women],[ it was mean = 2 mm; SD = 1.3 mm. No significant differences were found in the distance at P > 0.05. Inferior mandibular cortex appeared away from inferior bone lamella of IAC in men (mean = 7.10 mm; SD = 2 mm) than that in women (mean = 6.74 mm; SD = 1.35 mm)[Table 2].
|Table 2: Sex variations for distance between mandibular second molar roots and mandibular cortex to inferior alveolar canal (in millimeters) by digital intraoral technique|
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The mesial root of M2 was found to be closest to superior bone lamella of IAC in coterie I (mean = 3.1 mm; SD = 2.7 mm) than that in coterie II (mean = 3.49 mm; SD = 2.45 mm) with no significant difference in distance at P > 0.05. However],[ the distal root of M2 was away from the superior bone lamella of IAC in coterie II (mean = 3.20 mm; SD = 2.20 mm) with no significant difference in the distance at P > 0.05. The distance of inferior mandibular cortex was shorter for coterie I (mean = 7.16 mm; SD = 2.22 mm) than that for coterie II (mean = 7.33 mm; SD = 2.5 mm) with no significant difference in the distance at P > 0.05 [Table 3].
|Table 3: Age coterie’s variations for distance between mandibular second molar roots and mandibular cortex to inferior alveolar canal (in millimeters) by digital panoramic|
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In coterie I],[ non-significant shorter distance of mesial roots of M2 (mean = 3.1 mm; SD = 2.7) to superior bone lamella of IAC than coterie II (mean = 4 mm; SD = 2.55) at P > 0.05. Also],[ the distal root of M2 appeared far away from the superior bone lamella of IAC in coterie II (mean = 3.22mm; SD = 2.21 mm) than that in coterie I (mean = 2.56 mm; SD = 1.10 mm) with no significant differences in the distance at P > 0.05. In coterie I],[ the inferior mandibular cortex was near to the inferior bone lamella of IAC (mean = 7.11 mm; SD = 2.10 mm) than coterie II (mean = 7.32 mm; SD = 2.4 mm) with no significant differences in the distance at P > 0.05 [Table 4].
|Table 4: Age coterie’s variations for distance between mandibular second molar roots and mandibular cortex to inferior alveolar canal (in millimeters) by digital intraoral technique|
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| Discussion|| |
Both periapical and panoramic radiographs are possible solutions to preoperative assessment of posterior mandibular teeth with relation to IAC to avoid any damages caused postoperatively],[ such as ach and paresthesia. The digital techniques had permitted to measure the distances between M2 and mandibular cortex to IAC.
In this study, it was observed that by using both digital techniques, the mesial and distal roots of M2 to superior bone lamella of IAC for men had longer distances from IAC than those for women. Sato et al. (0.95 mm of mesial root to IAC in men and 0.56 mm for women, whereas 0.83 mm of distal root to IAC in men and 0.49 mm for women) and Fahd et al. (2.73 mm of mesial root to IAC in men and 1.7 mm of mesial root to IAC in women, whereas 2.1 mm of distal root in men to IAC and 1.0 mm of distal root in women to IAC) found that M2 roots in men were away from IAC superior bone lamella than those in women.
However, the measurements of the inferior mandibular cortex to inferior bone lamella of IAC were closest in women than those in men. These results were found to be consistent with the results of a study by Yusuke et al. (7.19 mm in men and 6.62 mm in women), using both digital techniques.
In young aged coterie I, the M2 roots (mesial and distal roots) were near to IAC than the older aged coterie II by both digital radiographic techniques. These results were not consistent with the results of a study by Yusuke et al. (7.42 mm in younger persons and 7.08 mm in the older persons).
Both digital techniques showed that the distances of inferior mandibular cortex to inferior bone lamella of IAC in coterie I were shorter than those in coterie II. Umadevi et al. found them to be equal in all age-groups (6.1 mm).
Digital imaging techniques provide the examiner better quality with enhancement, and less exposure to radiation than conventional one (field limitation manner by panoramic), but both panoramic and intraoral methods have limitations to give the object in its three-sided views, especially to inferior mandibular cortex, which difficult to be included in intraoral depiction which had limited area of interest, so computed tomography has optimized 3-dimentional imaging modality, computed-helping programmer, which aids in configuration IAC course to different direction of relation to adjacent anatomical parts in order to evaluate any probable complexities of IAC related to any dental procedure in this area.,
In this study, digital dental radiographic techniques of imaging had serious benefits over conventional one because of the presence of digital modern modality such as the tool for measurement of distances from IAC to apices of roots of posterior mandibular teeth and mandibular cortex accurately, display of image at once on monitor and did not delayed until developing the film, so any technical errors can be modified.
Both digital techniques were get us the data that the females gender had the least distance of both mesial and distal roots to superior border of mandibular canal, with similar results were obtained for age-group between 20–35 years so they more dangerous categories of toxicity and complications after interventional dental operations (tooth exodontia, dental implant, and endodontic therapy) in the area of M2 tooth. So dental specialists should be taken care in such these cases to avoid postoperative crisis such as pain, and creep of the lower jaw.
We would like to thank the lecturer Waleed Khalid, Department of Basic Science, College of Dentistry, AL-Anbar University, Anbar, Iraq, for his great support and effort.
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]