|Year : 2019 | Volume
| Issue : 2 | Page : 40-46
The Use of Panoramic and Cephalometric Images to Guide Needle Placement for Inferior Alveolar Nerve Block in 7- to 12-Years-Old Children
Forough Akbari1, Taraneh Zeynalzadeh Ghoochani2, Adel Sharifi-Rayeni3, Mahshid Sadat Hosseini4, Amin Askary5
1 Department of Pediatric Dentistry, Dental School, Zahedan University of Medical Sciences, Zahedan, Iran
2 Department of Pediatric Dentistry, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran
3 Department of Oral and Maxillofacial Surgary, Mashhad University of Medical Sciences, Mashhad, Iran
4 Zahedan University of Medical Sciences, International Branch of Chabahar, Zahedan, Iran
5 Department of Orthodontic Dentistry, Dental School, Zahedan University of Medical Sciences, Zahedan, Iran
|Date of Web Publication||6-Sep-2019|
Department of Orthodontic Dentistry, Dental School, Zahedan University of Medical Sciences, Zahedan
Source of Support: None, Conflict of Interest: None
Introduction: Pain management is one of the most important aspects of behavioral controlling in pediatric dentistry. Local anesthesia by inferior alveolar nerve block (IANB) is the primary method used for pain controlling in pediatric dentistry, and access to the mandibular foramen is the prerequisites for the success of this technique. However, the position of the mandibular foramen relative to the occlusal plane is not the same in all individuals. The aim of this study was to evaluate the effect of age and vertical facial dimension on the relative location of mandibular foramen in children aged 7 to 12 years using panoramic and cephalometric images. Materials and Methods: In this descriptive-analytical study, the cephalometric and panoramic images archived in Zahedan Faculty of Dentistry, belonging to 150 patients aged 7 to 12 years, were analyzed. Based on cephalometric analysis, these images were divided into three groups of short, normal, and long in terms of facial height, and they were divided into three age groups as well. With the help of panoramic radiography, position of the mandibular foramen was studied from different directions. The association of age and vertical facial dimension with the location of mandibular foramen was studied through ANOVA analysis and Kruskal-Wallis test. Kolmogorov–Smirnov test was used for checking the normality. Results: The results indicated that the mean and standard deviation of the anterior–posterior position of mandibular foramen (P = 0.201), the distance between the foramen and the edge of the condyle (P = 0.217), and the distance from the lower edge of the mandible (p = 0.051) showed no significant difference in all age groups. However, the mandibular foramen distance from the occlusal plane in patients aged 7 to 8 years was significantly less than in patients in the age group of 9 to 10 and 11 to 12 years (P < 0.001). Moreover, no significant difference in any of the variables under study was found between the short, normal, and long face groups (P > 0.05). Conclusion: According to the findings of this study, the needle should be inserted directly on the opposite side of the occlusal plane for the IANB anesthesia in case of children 7 to 8 years old. In other older age groups, the needle should be inserted parallel to the occlusal plane at a distance of 2 mm.
Keywords: Inferior alveolar nerve block, panoramic image, cephalometric image, children
|How to cite this article:|
Akbari F, Ghoochani TZ, Sharifi-Rayeni A, Hosseini MS, Askary A. The Use of Panoramic and Cephalometric Images to Guide Needle Placement for Inferior Alveolar Nerve Block in 7- to 12-Years-Old Children. Dent Hypotheses 2019;10:40-6
|How to cite this URL:|
Akbari F, Ghoochani TZ, Sharifi-Rayeni A, Hosseini MS, Askary A. The Use of Panoramic and Cephalometric Images to Guide Needle Placement for Inferior Alveolar Nerve Block in 7- to 12-Years-Old Children. Dent Hypotheses [serial online] 2019 [cited 2020 Jan 20];10:40-6. Available from: http://www.dentalhypotheses.com/text.asp?2019/10/2/40/266201
| Introduction|| |
One of the most important aspects of behavioral controlling in pediatric dentistry is pain management. There are various medicinal methods for controlling pain and helping to cope with pain before, during, and after treatment. Most of these strategies include the use of anesthesia and sedatives. Specifically, local anesthesia is still the primary method for pain management in pediatric dentistry. In general, when deep restoration or surgery is needed on the mandible permanent or deciduous teeth, the inferior alveolar nerve must be blocked. The inferior alveolar nerve block (IANB) is the most common anesthetic technique used in dentistry. However, there is no consensus on the position of the mandibular foramen in relation to children’s occlusal plane to place the needle in a standard place.
The mandibular bone is composed of thick cortical plates with spongy bone that are structurally different from the maxilla bone. The mandibular foramen is located on the inner surface of the ramus and is intended to cross the mandibular nerves and arteries. The mandibular canal starts from the mandibular foramen and goes down diagonally and directly on the Ramus; it then goes to the trunk of the mandible, which includes inferior alveolar nerve. Although the lower alveolar nerve block is the most common anesthesia technique in dentistry, its success rate is low. In growing group, the distance from the gonial point to the mandibular foramen and also distance from mandibular foramen to anterior border of ramus increases with age and facial height.
The currently accepted technique for lower alveolar nerve block is to position the thumb on the occlusal surface of the molar teeth so that the fingertip can be located on the internal oblique ridge and the thumb arranger can be located in the retromolar fossa. The syringe body should be directed from the permanent molars to the opposite side of the jaw arch. It is advised that a small amount of anesthetic substance be injected immediately after entering the soft tissue, and then the needle should be directed to the mandibular foramen. The penetration depth of the needle is about 15 mm, but this varies depending on the patient’s age and his mandibular size.
Panoramic view is one of the most common radiographies used in dentistry. Many dentists propose panoramic radiography as a screening view for investigating dental-mandibular problems and damages, in addition to its being easy and convenient to access. Panoramic radiography is also one of the most commonly used methods for determining the location of mandibular foramen. Altunsoy et al., in 2016, studied the position of mandibular foramen in children and adolescents aged 8 to 18 years with the help of CBCT. They analyzed data from 63 girls and 64 boys. The measured variables included the distance between mandibular foramen (MF) and the anterior border of the ramus (A), posterior border of the ramus (P), the most inferior cut of the mandible (MI), the upper curvature point on the Mandibular Notch (MN), and direct line connecting the mandibular molar cusps (O). The results showed that the distances of MN-MF, MI-MF, and A-MF were significantly higher in girls aged 9, 13, and 14 years than in boys of similar age. Also, there was no significant difference in the O-MF variable between girls and boys at any age. It was also observed that the variables P-MF, MN-MF, and MN-MF increased with age. In another study conducted by Hazarey et al. in 2015, in India the position of mandibular canal in relation to mandibular plane was studied and compared in different growth patterns. They examined 100 lateral cephalometric images using orthodontic landmarks and divided the images, based on the growth pattern, into three groups: normal, horizontal growth, and vertical growth. Then they examined the variables related to mandibular foramen and inferior alveolar canal in the images. Based on the results of this study, it was concluded that the gap between “gonial point to mandibular foramen,” “mental foramen to mandible border,” and “foramen mandible to vertical pterygoid” increased in patients with horizontal growth pattern and reduced in patients with vertical growth pattern. Park et al., in a study conducted in 2015, compared the location of mandibular foramen in normal occlusion and class 2 and 3 skeletal malocclusions using CBCT. The results of the study showed that the distance of anterior border of Ramus to the mandibular foramen was not significantly different in the three groups, but in skeletal class 3, this difference was significantly higher in men than in women. Additionally, in skeletal class 3, the mandibular foramen was located higher than the other two groups. The results of this study also showed that the diameter of mandibular foramen was not significantly different between the three groups. In a study conducted in South Korea in 2013, Kang et al. examined the mandibular foramen and anatomical landmarks by three-dimensionally reconstructed CT images. In this study, three-dimensional images of mandible of 49 patients aged 8 to 16 years and 59 patients aged 16 to 25 years were examined. The results of the study showed that the distance between the anterior ramus and the mandibular foramen, as well as the distance between the gonion and mandibular foramen, increased with age.
Considering the importance of the anesthesia by the lower nerve block in dental work and the discrepancies in the results of the researches conducted so far, in the current study, we aim to determine the effect of age and vertical facial dimension in the position of mandibular foramen in children aged 7 to 12 years using panoramic and cephalometric images.
| Materials and Methods|| |
Study protocol approved by local research ethics committees (No. 2200). In this descriptive-analytical study, the sample population under investigation included the initial cephalometric and panoramic radiographs of patients who underwent orthodontic treatment in the clinic of the Department of Orthodontics, School of Dentistry, Zahedan University of Medical Sciences. Patients whose radiographic records were of inferior quality, and those with obvious asymmetry (>5 mm at the lower border of the ramus) and syndromes or history of maxillofacial injury, were excluded from the study. The convenient sampling method was performed according to the data collected systematically from the files and checklists.
We examined 150 panoramic and lateral cephalometric radiographic images of the age groups 7 to 8, 9 to 10, and 11to 12, which were archived in the orthodontics department of the Faculty of Dentistry at the University of Zahedan, with cooperation between the orthodontist and radiologist. All radiographs were taken with the same radiological equipment. Panoramic and lateral cephalometric radiographics were taken using Pax-I insight (Vatech, Gyeonggi-do, South Korea). Kodak X-ray 15 × 30 cm film (Carestream Health Inc., Bagnolet, France) was used for panoramic view, and Kodak X-ray 24 × 30 cm film was used for lateral cephalometric view. All radiographs were digitized (300 dpi, grayscale mode) using a flatbed scanner (Epson Expression 1600 Pro; Seiko Epson Corp, Nagano, Japan) and stored in a jpeg format. They were finally traced manually by an orthodontist.
Similar to a previous study, here we use a series of points, lines, and angles to determine the position of mandibular foramen. In panoramic image, these points include condyle (Co), which indicates the top of the condyle; mandibular foramen (Mf); mandibular angle (Ma), point on the contour of the mandible obtained by bisecting the tangents to the corpus and ramus of the mandible; and Pco, Pmf, and Pma, projections of Co, Mf, and Ma on the ramus tangent, respectively [Figure 1].
In the cephalometric analysis, the following points were investigated:
Anterior nasal spine (Ans) indicates the apex of the anterior nasal spine. Posterior nasal spine (Pns) specifies the intersection point of soft palate, hard palate, and pterygopalatinal fissure; nasion (N)—anterior limit of the nasofrontal suture; sella (S)—center of sella turcica; menton (Me)—lowest point of the symphysis; pogonion (Po)—most anterior point of the symphysis; articulare (Ar)—radiographic intersection of the posterior margin of the ramus with the basion; mandibular foramen (Mf); Mfo—projection of Mf on the functional occlusal plane; gonion (Go)—point on the contour of the mandible obtained by bisecting the angle Ar-Go′-Me′; soft nasion (N′)—deepest point of the profile; subnasale (Sn)—point at which the nasal septum merges with the upper cutaneous lip; soft menton (Me′)—point on the contour of the chin obtained by bisecting the angle formed by Go′-Me and N-Po; Ap—intersection of a line parallel to the occlusal plane through Mf with the anterior margin of the ramus; and Pp—intersection of a line parallel to the occlusal plane through Mf with the posterior margin of the ramus [Figure 2].
For assessment, vertical position of mandibular foramen Pmf_Pco and Pmf_Pma distance in panoramic view and Mf_Mfo distance in lateral cephalometric were used. Anterior–posterior position of mandibular foramen was evaluated with the ratio of the foramen distance from the anterior border of ramus to the ramus width in lateral cephalometric view.
The mentioned points and landmarks of the lateral cephalometric and panoramic radiographies were identified by an orthodontist. Radiographs were analyzed using the Y-axis and Jarabak index method. The Jarabak index shows the proportion of the posterior height to the anterior height in the following equation:
Jarabak index increases in short face children and decreases in children with long facial height.
The Y-axis represents the NSGn angle (the angel relative to nasion, sella, and gnathion), which is normally 66°. An increase in this angle shows a vertical rotation of the mandible, and a decrease indicates a horizontal rotation. The measurement of Gn, Me, N, Go, S angles, and others, as well as the status of short face, long face, and normal face, was performed according to the Y-axis and Jarabak index cephalometric analysis [Table 1].
In all images, the patient’s right and left sides were compared and, if aligned, the left side was used as a reference. The position of the mandibular foramen was specified through panoramic view, which is a lucency, and it is the origination of the mandibular canal. Subsequently, the anterior–posterior position and the vertical distance of the foramen to the occlusal plane and the head of the condyle and the lower border of the mandible were measured in different ages and different facial height groups. Radiographs were evaluated separately by two observers. All data extracted from the images were recorded in a checklist that included age, gender, vertical height of the face, and the indices of mandibular foramen distance. Data were analyzed using SPSS software, version 20 (SPSS Inc., Chicago, Illinois, USA). Comparison of the indices of mandibular foramen distance in the age groups and facial height groups was done through ANOVA analysis (when the distribution of the data was normal) and the Kruskal‐Wallis test (when the distribution was not normal). Kolmogorov-Smirnov test was used for checking the normality. Follow-up tests were used if the results were significant.
| Results|| |
In the present study, the location of mandibular foramen and its relationship with age and vertical facial dimension in 150 children aged 7 to 12 years old were investigated. [Table 2] shows the demographic information of the participants in this study.
[Table 3] shows the vertical position of mandibular foramen and occlusal plane. Statistical analysis of variance showed no significant difference between age groups in terms of the vertical position of mandibular foramen relative to the head of the condyle and relative to the mandibular lower border. However, a statistically significant difference between the age groups was detected in the position of occlusal plane relative to mandibular foramen vertical position (P < 0.001).
|Table 3 Comparison of mandibular foramen vertical position relative to the head of the condyle, mandibular lower border, and occlusal plane in the age groups under study|
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In group comparison of mean and standard deviation of mandibular foramen vertical position relative to occlusal plane based on Tukey HSD test, significant differences were observed between 7 to 8 years and 9 to10 years age groups (P < 0.0001) and also between 7 to 8 years and 11 to 12 years age groups (P < 0.0001).
[Table 4] shows the mean and standard deviation of mandibular foramen distance from the head of the condyle in different patterns. The differences here were not statistically significant based on ANOVA test (P = 0.797). The mandibular foramen distance from the lower border of mandibular border and from the occlusal plane also did not show a statistically significant difference between patterns based on ANOVA test ([Table 4]).
|Table 4 Comparison of mean and standard deviation of mandibular foramen distance from the head of the condyle, lower border of mandibular border, and occlusal plane in different facial patterns|
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About the means in age groups (7–8 years: 55.09 ± 9.52; 9–10 years: 56.03 ± 10.00; 11–12 years: 58.18 ± 8.69) and facial patterns (short face: 7.39 ± 58.22; normal face: 7.14 ± 54.13; and long face: 10.04 ± 57.18), the anterior–posterior position of mandibular foramen was not significantly different (P = 0/201, P = 0.764).
| Discussion|| |
In the present study, stereotypical panoramic radiographs of 150 patients were divided into three groups of age and three groups of facial pattern/height. The position of mandibular foramen was then evaluated in these patients. We observed that the anterior–posterior position of mandibular foramen was not significantly different between the age groups (P > 0.05). The anterior–posterior position of mandibular foramen in the subjects under study was on average in middle one-third of the mandibular ramus (slightly bowed to the posterior). The current study was in line with the study conducted by Ono et al. They also concluded in their study that there was no difference between the anterior–posterior position of mandibular foramen in the different age groups, and this landmark has been located in the middle one-third of the mandibular ramus. The average distance between the mandibular foramen and the head of the condyle was 24.1 mm and was not significantly different between different facial patterns. Our findings are consistent with Tafakhori et al. They also showed that the mandibular foramen in different age groups did not show a significant difference regarding the vertical dimension.
Moreover, we show that the mandibular foramen distance from the lower border of mandibular trunk is not significantly different among the individuals of different age groups. This distance was on the average of 23.2 mm. This also confirms the results of the study conducted by Tafakhori et al.
Our results show that the mandibular foramen distance relative to the occlusal plane in the patients of the age group of 7 to 8 years is significantly lower than the other two groups, and the other two groups did not show a significant difference in this regard between themselves. The reason for this could be the incomplete growth of molar teeth of children 7 to 8 years old compared to older ones. This is in contrast with what Altunsoy et al. reported, since they did not find a significant difference between the different age groups in terms of the distance of mandibular foramen from the occlusal plane. This discrepancy could potentially be explained by the differences in the statistical population and techniques used. Altunsoy et al. used the cone beam computed tomography technique (CBCT), whereas panoramic radiography was used in our study.
The findings of the present study are also consistent with Navin et al. In a study done on 90 radiographic images of orthodontic patients aged 7 to 12 years, they found that the mandibular lingula distance from the occlusal plane showed a gradual increase in three age groups, which was statistically significant. By increasing the age, the distance between the mandibular foramen and lingula increased from the occlusal plane. They also found that the mandibular foramen position in each of the age groups (7–12 years) was not bilaterally symmetrical.
In this study, we did not detect a significant difference in the anterior–posterior position of mandibular foramen among the individuals of short face and long face. In this regard, the present study is not consistent with the study of Hazarey et al. Hazarey et al. suggested that the mandibular foramen of individuals with horizontal growth of the mandible (short face) tends to have more posterior position than in others. The reason for this difference could be attributed to the difference in the measurement method of the two studies. In Hazarey et al., the foramen distance from the vertical pterygoid was used to measure the anterior–posterior position of mandibular foramen, while in the present study, the ratio of the foramen distance from the anterior border of ramus to the ramus width was used.
Here, we also report that the mandibular foramen distance from the head of the condyle was not significantly different in different groups in terms of face pattern. To the best of our knowledge, this variable has not been studied in similar settings earlier.
Also, we found no significant difference between the foramen distance from occlusal plane between individuals with short face and long face. This distance was 2 mm on the average. There was also no significant difference between the two groups in terms of the distance of mandibular foramen from the lower edge of mandible border. In general, there seems to be no significant difference in the position of mandibular foramen between the two groups of long face and short face. But Epars et al. suggested that each of the skeletal variables describing the vertical facial morphology presented a significant correlation with the vertical position of the mandibular foramen. They used intermaxillary angle to evaluate different facial pattern and only Caucasian patients were included .Perhaps the difference between the results of these two articles may be due to these reasons.
In the light of the above, the results of this research showed that the location of mandibular foramen on the ramus in different individuals in terms of face height was not different. This landmark is on the average in the middle one-third of the mandibular ramus slightly bowed to the posterior and with a distance of 2 mm from the occlusal plane. Also, according to the findings of this study, the needle should be inserted on the opposite side of the occlusal plane for the IANB anesthesia of 7 to 8 years old children. In older age groups, the needle should be inserted parallel to the occlusal plane at a distance of 2 mm and the anesthetic solution should be discharged in the middle one-third of the mandibular ramus.
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Conflicts of Interest
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[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3], [Table 4]