|Year : 2017 | Volume
| Issue : 1 | Page : 15-19
Influence of gender and age on nasopalatine canal: A cone-beam computed tomography study
Richa Mishra1, VB Thimmarasa1, Prashant P Jaju1, Ritu Mishra2, Arpan Shrivastava3
1 Department of Oral Medicine and Radiology, Rishiraj College of Dental Science and Research Center, Bhopal, Madhya Pradesh, India
2 Department of Oral Pathology and Microbiology, Rishiraj College of Dental Science and Research Center, Bhopal, Madhya Pradesh, India
3 Department of Public Health Dentistry, Rishiraj College of Dental Science and Research Center, Bhopal, Madhya Pradesh, India
|Date of Web Publication||13-Feb-2018|
Dr. Richa Mishra
Department of Oral Medicine and Radiology, Rishiraj College of Dental Science and Research Center, Gandhi Nagar, Bhopal - 462 036, Madhya Pradesh
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Background and Aim: The incisive canal (or nasopalatine duct) is located palatal to the maxillary central incisors and connects the palate to the floor of the nasal cavity. A branch of the greater palatine artery, the nasopalatine artery, and the nasopalatine nerve passes through this canal. A proper three-dimensional image of the incisive canal and foramen before any surgical intervention in the anterior maxilla is highly important since it can help determine the morphology and position of the canal in relation to the surrounding structures. The aim of this article is to analyze the influence of gender and age on the morphology and length of nasopalatine canal (NPC) using cone-beam computed tomography (CBCT).
Study Design: This retrospective study analyzed 100 CBCT scans of patients between 15 and 75 years enrolled at a CBCT center in Bhopal, India. The images were acquired using Sirona's Orthophos SL. Two oral and maxillofacial radiologists examined all images to analyze the morphology and length of NPC with respect to gender and age.
Results: Morphologically, there were four different shapes of NPC in sagittal CBCT section, and most common was cylindrical both in males and females. Least common shape seen was spindle shape in both genders. The NPC length decreased with increase in age. The length of the canal was found to be longer in men.
Conclusion: This study highlights the importance of morphology of NPC during surgical procedures such as implant planning.
Keywords: Cone-beam computed tomography, incisive canal, nasopalatine canal
|How to cite this article:|
Mishra R, Thimmarasa V B, Jaju PP, Mishra R, Shrivastava A. Influence of gender and age on nasopalatine canal: A cone-beam computed tomography study. J Dent Implant 2017;7:15-9
|How to cite this URL:|
Mishra R, Thimmarasa V B, Jaju PP, Mishra R, Shrivastava A. Influence of gender and age on nasopalatine canal: A cone-beam computed tomography study. J Dent Implant [serial online] 2017 [cited 2018 May 23];7:15-9. Available from: http://www.jdionline.org/text.asp?2017/7/1/15/225400
| Introduction|| |
The nasopalatine canal (NPC), also known as the incisive canal or anterior palatine canal, is a long slender passage present in the midline of the anterior maxilla that connects the palate to the floor of the nasal cavity. The canal continues in the oral cavity as a single incisive foramen posterior to the central incisor teeth and in the nasal cavity as the foramina of Stenson, which are usually two in number. The canal contains the nasopalatine (incisive) nerve and the terminal branch of the descending nasopalatine artery, as well as fibrous connective tissue, fat, and even small salivary glands., Nevertheless, anatomical variations of the NPC are not very well documented in the literature and are often presented as case reports.,,,
A proper image of the incisive canal and foramen before any surgical procedure such as implant placement in the anterior maxilla is highly important. In the anterior maxilla, patients consider the esthetic outcome to be an essential factor, often surpassing even functional aspects of the dental implant therapy. Treatment failures can lead to challenging clinical situations that may only be corrected with the removal of the implant and subsequent tissue augmentation procedures. Implant contact with neural tissue may result in failure of osseointegration or lead to sensory dysfunction. In view of these potential complications, the morphology and dimensions of the NPC should be properly evaluated before placement of dental implants in the vicinity of this anatomical structure. Two-dimensional imaging (intraoral and panoramic radiography) and cross-sectional techniques (spiral and computed tomography [CT]) used to be the available methods. However, cone-beam CT (CBCT) has recently been proposed as a valuable three-dimensional imaging technique in dentistry. Compared to spiral tomography, CBCT has the advantage of high resolution and elimination of superimposition. In addition, compared to CT, CBCT has many other benefits, including lower radiation dose and shorter imaging time.,, CBCT technology has facilitated the precise three-dimensional evaluation of bone quantity and position of NPC in the anterior maxilla.
The objectives of this study were to analyze the morphology of the NPC, to assess the correlation between the gender and morphology of the canal, and to assess the correlation between age, gender, and length of the canal.
| Materials and Methods|| |
The main source of data for this retrospective study was CBCT scans of patients enrolled at a CBCT center in Bhopal, India. The study material included 100 CBCT scans of patients that included the entire NPC in all three planes. For all these 100 patients, age range was 15-75years. The CBCT scans from the patients with NPC pathology or impacted teeth in the region were excluded from the present study. The images were acquired using Sirona's Orthophos SL with resolution of 150 microns and the data of the CBCT images were sliced in three dimensions. Two specialists in oral and maxillofacial radiologist analyzed all of the images.
| Evaluation of Images|| |
Shape of the canal was observed in the sagittal section and classified as-
- A cylindrical shape formed by parallel labial and palatal walls of the NPC [Figure 1]a
- A funnel shape formed by an increasing anteroposterior dimension of the NPC from the nasal fossa to the hard palate [Figure 1]b
- An hourglass shape in which the narrowest anteroposterior dimension of the NPC was at the mid-level compared to the dimensions at the nasal fossa and hard palate levels [Figure 1]c
- A spindle shape in which the widest anteroposterior dimension of the NPC was at the mid-level compared to the dimensions at the nasal fossa and hard palate levels [Figure 1]d,
|Figure 1: Cone-beam computed tomography images show the four shapes of the nasopalatine canal as seen on sagittal planes. (a) Cylindrical shape, (b) funnel shape, (c) hourglass shape, (d) spindle shape|
Click here to view
Length of the canal was measured between the floor of the nasal fossa and the level of the hard palate along the long axis of the canal in the sagittal section of CBCT scan. Length was measured using digital length measuring tool.
| Results|| |
Morphology of the canal and correlation between gender and morphology of the canal
The shape of the NPC differed among cases in the sagittal view. The NPCs were thus classified into four categories according to their shape viewed on the sagittal sections: cylindrical, funnel, spindle, or hourglass [Figure 1]. The most commonly encountered shape was the cylindrical shape, which was seen in 62 participants, and the least common was the spindle shape, seen in 2 participants [Figure 3]. The most common shape of NPC was cylindrical in both genders. However, spindle-shaped canal was least common among females (2) while there was no reported case of spindle-shaped canal in case of male [Figure 4].
|Figure 2: Sagittal cone-beam computed tomography image for measuring length of the canal|
Click here to view
Correlation between age, gender, and length of the canal
As viewed on the sagittal plane, the length of the NPC was measured between the level of the nasal fossa and the level of the hard palate along the long axis of the canal [Figure 2]. It ranged from 5.36 mm to 16.04 mm in male with a mean of 10.5144 mm and from 6.15 mm to 14.15 mm in female with a mean of 9.9856 mm. This shows that length of the NPC is relatively greater in male than in female [Table 1].
It was observed that with the advancement of age length of the canal was decreasing in both the genders [Table 2] and [Table 3].
| Discussion|| |
There is a close anatomical relationship between the NPC and the root of the central maxillary incisors; a careful radiological analysis is necessary when insertion of a dental implant or any other surgical procedure is planned in that region. However, data about anatomical variations, dimensions, and typical morphology of the NPC are scarce in the literature. Hence, this study was undertaken to evaluate the morphological changes in NPC using CBCT.
The present study indicated that the NPC showed a great deal of variability with regard to its dimensions as well as to its morphological appearance. In our study, four anatomical shapes of NPC have been reported in the sagittal CBCT slice.
Study done by Thakur et al. in 2013 reported that a cylindrically shaped NPC was most commonly observed. In accordance with this, in our study, the cylindrical shape (62%) was found in most of the participants, funnel-shaped canal was found in 27% subjects, hourglass 9%, and spindle shape 2%. Our results are also consistent with the ones of Mardinger et al., Tözüm et al., Yaser et al., Liang et al., Asaumi et al., Panjnoush et al., Fernández-Alonso et al., and Nasseh et al. who found that the NPC cylindrical shape was the most frequent.
In contrast to our study, Mraiwa et al. showed difference in findings, where the Y-shaped corresponding to the funnel in our study was the most common (22 out of 34; [64.70%]) against the cylindrical (8 out of 34; [23.52%]). Similarly, Fukuda et al. in 2015 also reported that the funnel shape was most common (50%). With funnel shaped, expansion of the incisive foramen is observed, so depending on the angle of implant placement, there is a risk of perforating the IC and damaging the nasopalatine nerves and arteries.
As for the average length of the NPC, in our study, it was found to be 10.24 mm ranging from 6.15 mm to 16.04 mm; results close to the ones of Thakur et al., Tözüm et al., and Fukuda et al. whose mean canal length measurement in a sagittal plane was 10.08 ± 2.25, 10.86 ± 2.67, and 11.75 ± 1.70 mm, respectively. On the other hand, higher length canal means were identified by Al-Amery et al., Panjnoush et al., Kajan et al., Yaser et al., and Song et al. were, respectively, 16.33 ± 4.43, 14.1 ± 3.0, 12.84 ± 2.88, 12.85 ± 2.63, and 12.0 mm (8.4–15.8 mm). While shorter mean value length was detected by Mraiwa et al., which was 8.1 ± 3.4 mm, Liang et al. in their study assessed the length of the NPC as 9.9 (±2.6) mm.
Interestingly, in our sample, the female canals are significantly shorter than the male ones, a thing which was supported by the findings of Thakur et al., Tozum et al., Kajan et al., Yaser et al., Esmaeili et al., Liang et al., and Salami et al. The greater length of the NPC in the males (16.04 mm) could be ascribed to the relatively larger craniocaudal dimension of the face observed in the males as compared to the females, and the differences in the size of the NPC could be relative to the facial dimensions rather than absolute.
In our study, length of NPC decreases with increasing age which is in accordance with the study done by Fernández-Alonso et al., whereas Al-Amery et al. and Esmaeili et al. found that there is no relation between length of the canal and advancing age of the study participants. In contrast to our finding, Liang et al. noticed an increase in NPC length with advancement of age. The précised reason for this relation is not understood.
| Conclusion|| |
This study highlighted the anatomic variability of the NPC in relation to several parameters. The findings from this study suggest that gender is an important factor that can affect the characteristics of the IC and the amount of bone anterior to it. The difference observed from the previously reported studies could be due to population variation or variability in the imaging techniques used to assess the NPC. The shape of the canal and its anteroposterior dimensions are the most significant parameters for placement of implants in the maxillary incisor region.
Diya dental imaging, bhopal
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1], [Table 2], [Table 3]