scholarly journals Assessment of the Retromolar Canal in Taiwan Subpopulation: A Cross-Sectional Cone-Beam Computed Tomography Study in a Medical Center

Tomography ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 219-227
Author(s):  
Yen-Wen Shen ◽  
Wan-Chun Chang ◽  
Heng-Li Huang ◽  
Ming-Tzu Tsai ◽  
Lih-Jyh Fuh ◽  
...  
Keyword(s):  
Medical Center ◽  
Third Molar ◽  
Mandibular Canal ◽  
Cone Beam ◽  
Horizontal Distance ◽  
Taiwanese Population ◽  
Mandibular Bone ◽  
Second Molar ◽  
The Third ◽  
Retromolar Canal

The retromolar canal is an anatomical variation that occurs in the mandibular bone. The retromolar canal typically originates in the mandibular canal on the distal side of the third molar and extends forward and upward to the retromolar foramen (RMF), which contains the neurovascular bundle. Accidentally damaging the neurovascular bundle in the retromolar canal during the extraction of the third molar, dental implant surgery, or maxillofacial orthognathic surgery may lead to subsequent complications such as incomplete local anesthesia, paresthesia, and bleeding during operation. The objective of this study was to investigate the prevalence of the RMF in the Taiwanese population in a medical center by using dental cone-beam computed tomography (CBCT) and to identify the position of the RMF in the mandibular bone. The dental CBCT images for the mandibular bone of 68 hemi-mandible were uploaded to the medical imaging software Mimics 15.1 to determine the prevalence of the RMF in the Taiwanese population and the three positional parameters of the RMF in the mandibular bone: (1) The diameter of the RMF, (2) the horizontal distance from the midpoint of the RMF to the distal cementoenamel junction of the second molar, and (3) the vertical distance from the midpoint of the RMF to the upper border of the mandibular canal. Seven RMFs were observed in the 68 hemi-mandibles. Thus, the RMF prevalence was 10.3%. In addition, the diameter of the RMF was 1.41 ± 0.30 mm (mean ± standard deviation), the horizontal distance from the midpoint of the RMF to the distal cementoenamel junction of the the second molar was 12.93 ± 2.87 mm, and the vertical distance from the midpoint of the RMF to the upper border of the mandibular canal below second molar was 13.62 ± 1.3487 mm. This study determined the prevalence of the RMF in the Taiwanese population in a medical center and its relative position in the mandibular bone. This information can provide clinicians with a reference for posterior mandible anesthesia and surgery to ensure medical safety.

scholarly journals The Anatomical Position and Size of Greater Palatine Foramen and Canal in an Iranian Sample Using Cone Beam Computed Tomography

2021 ◽  
Author(s):  
Solmaz Valizadeh ◽  
Seyedeh Mahshid Ahmadi ◽  
Mitra Ghazizadeh Ahsaie ◽  
Zahra Vasegh ◽  
Navid Jamalzadeh
Keyword(s):  
Computed Tomography ◽  
Average Length ◽  
Third Molar ◽  
Cone Beam ◽  
P Value ◽  
Second Molar ◽  
Anatomical Position ◽  
The Third ◽  
Greater Palatine Foramen ◽  
The Right

Abstract IntroductionDetection of exact location of greater palatine foramen and its anatomical variations are vital prior to posterior maxillary surgeries and gingival grafts. The aim of this study is to determine the anatomical position and size of the greater palatine canal (GPC) and foramen (GPF) using cone beam computed tomography (CBCT) scans.Materials and methodsIn this descriptive-analytic study, CBCT images of 148 patients were assessed. To determine the anatomical foramen position, the posterior maxilla area was divided into five regions on the axial view (A: from the mesial surface of the second molar to the center of the second molar, B: from the center of the second molar to its distal, C: from the mesial surface of the third molar to the center of the third molar, D: from the center of the third molar to the distal of the third molar, E: distal to the third molar.). The length of the canal was investigated on both coronal and sagittal views. Independent and paired T-test were used to analyze the data.ResultsAmong 80 females -68 males, the anatomical position of the GPF was mainly located in region E on the left (55%) and the right (50%), and then, respectively, in region D and region C. The mean diameter of GPF was 4/48 mm on the left and 4/63 mm on the right side (P-value = 0/01). The average length of the canal on the coronal view was 29.46 mm on the left side and 29.75 mm on the right (P-Value = 0/005). The average length of the canal on the sagittal view was 29.62 mm on the left and 30.02 mm on the right (P-value = 0/001).ConclusionThe anatomical position of the GPF was primarily located distal to the third maxillary molar. CBCT is a valuable diagnostic tool for evaluation of vital anatomic landmarks in the maxillofacial region prior to surgeries and interventions.

A longitudinal study on timing and velocity of rat molar eruption: Timing of rat molar eruption

2018 ◽  
Vol 52 (4) ◽  
pp. 394-401 ◽  
Author(s):  
Balazs J Denes ◽  
Aikaterini Lagou ◽  
Domna Dorotheou ◽  
Stavros Kiliaridis
Keyword(s):  
Mixed Model ◽  
Third Molar ◽  
Mandibular Canal ◽  
Reference Points ◽  
Micro Computed Tomography ◽  
Eruption Rate ◽  
Second Molar ◽  
Mixed Model Analysis ◽  
The Third ◽  
Rat Molar

Rat molar eruption and occlusion data were compiled from several studies but several inconsistencies were found, rendering the planning of eruptional studies difficult and imprecise. Our aim was to measure eruption and occlusion days, as well as eruption velocity, in the upper and lower three molars from infancy to end of adolescence in the rat. A total of 19 male and female Wistar rats were scanned daily by micro-computed tomography (CT) from day 15 to 70. We measured the eruption of all maxillary and mandibular molars with reference points at the hard palate and mandibular canal at three stages: pre-emergent, pre-occlusal, and functional. Statistical analysis was performed with a mixed-model analysis of variance (ANOVA) and a Sidak post hoc test. The first molar erupts on average on day 17, the second molar on day 20, and the third molar on day 33. The eruption velocity of the first molar was the highest at 90.9 microns/day (standard error (se) = 12.80), followed by the second molar at 65.9 microns/day (se = 5.80), and the lowest was the third at 47.0 microns/day (se = 3.28), ( p < 0.001). On average, the pre-occlusal phase had the highest velocity at 97.2 microns/day (se = 1.72), the pre-emergent was lower at 84.9 (se = 2.29), and the functional was the lowest at 21.7 (se = 0.45), ( p < 0.001). The eruption rate decreased from the first to third molar and was also different between phases: the pre-occlusal phase had the highest rate, closely followed by the pre-emergent phase while the functional eruption rate was significantly lower than the other phases.

scholarly journals Association between imaging and clinical findings in mandibular third molar surgeries

2018 ◽  
Vol 23 (1) ◽  
Author(s):  
Marcelo Bonifácio da Silva Sampieri ◽  
Danilo Da Silva Correa ◽  
Francisca Lívia Parente Viana ◽  
Thaís Sumie Nozu Imada ◽  
Josfran Da Silva Ferreira Filho ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Statistical Significance ◽  
Third Molar ◽  
Panoramic Radiograph ◽  
Mandibular Canal ◽  
Clinical Findings ◽  
Cone Beam ◽  
The Third ◽  
Close Relationship

Objective: it is important to evaluate the position andestablish the third molar relationship with the mandibularcanal to minimize the risk of nerve injury and assistin planning the extraction of this tooth. The panoramicradiograph is the standard diagnostic tool for this purpose.However, if it indicates a close relationship betweenthe third molar and the mandibular canal, furtherinvestigation using cone beam computed tomography(CBCT) may be recommended to check the three-dimensionalrelationship between the tooth and the mandibularcanal. Thus, this study aimed to correlate the clinicalfindings (observed in third molar surgeries) to imagingfindings (observed in panoramic radiographs andCBCT). Subjects and method: after the extraction of 20mandibular third molars, the panoramic radiograph andthe cone beam computed tomography were analyzed.Then, the surgical findings were correlated to the imagefindings. Results: It was observed that the radiographicfinding type 2 (darkening of roots) observed in the panoramicradiograph presented a greater relation to theabsence of cortical bone between the mandibular canaland the third molar (CBCT finding), with statistical significance(p

Evaluation of Mandibular Third Molar Region in a Turkish Population Using Cone-Beam Computed Tomography

2020 ◽  
Vol 16 (9) ◽  
pp. 1105-1110
Author(s):  
Büyük Kaan Orhan ◽  
Dilek Yılmaz ◽  
Mehmet Ozgur Ozemre ◽  
Kıvanç Kamburoğlu ◽  
Orhan Gulen ◽  
...  
Keyword(s):  
Statistical Significance ◽  
Third Molar ◽  
Mandibular Canal ◽  
Third Molars ◽  
Second Molar ◽  
The Third ◽  
Impacted Mandibular Third Molar ◽  
Mandibular Third Molar ◽  
The Relationship ◽  
Molar Region

Objectives: To evaluate impacted mandibular third molar tooth region and obtain linear measurements using CBCT images and to assess the relationship between the impacted third molar and the mandibular canal. Methods: CBCT scans of 351 patients (208 females, 143 males) were assessed. Age, gender, and impaction site were recorded for each patient. The relationship of third molars with the vertical axis of second molars, 2nd molar resorption and the relationship between third molar apices and the mandibular canal were assessed. In addition, the distance between ramus and second molar, mesiodistal width of the third molar, the angle between third molar and second molar, and width of the third molar capsule were measured. Binary Logistic Regression, Chi-Square Test, and General Linear Model were used for statistical analysis. Results: The highest percentage of impaction was found for mesioangular followed by transversal and vertical. The transversal impacted third molars revealed a significant association with adjacent second molar root resorption (p<0.001). There was a statistical significance between the second molar resorption and distance between ramus and second molar (p<0.001). The mesioangular impacted third molars revealed significant relation with the mandibular canal (p<0.05). The most frequent variation found was the dental canal followed by the retromolar canal. In general, higher measurement values were obtained for men when compared to women (p<0.05). Conclusion: CBCT assessment of the third molar region provided useful information regarding impacted mandibular third molar surgery operations.

scholarly journals Incidence and Anatomical Properties of Retromolar Canal in an Iranian Population: A Cone-Beam Computed Tomography Study

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
N. Nikkerdar ◽  
A. Golshah ◽  
M. Norouzi ◽  
S. Falah-Kooshki
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Third Molar ◽  
Iranian Population ◽  
Cone Beam ◽  
Third Molars ◽  
The Third ◽  
The Mean ◽  
Anatomical Properties ◽  
Retromolar Canal

Objectives. Retromolar canal (RC) is an anatomic structure, and due to increasing demand for surgical procedure in the retromolar area of the mandible, the identification of the retromolar canal has become an issue of clinical concern. It can innervate the third molar and some of the muscles around the posterior segment of the mandible, complicating surgical procedures in the retromolar area and root canal treatment of third molars. The aim of this study was to evaluate the incidence and anatomical properties of RC in a western Iranian population using cone-beam computed tomography (CBCT) images. Materials and Methods. Two hundred bilateral CBCT images were collected and screened in the three spatial planes for the presence of an RC. Anatomical properties and location of the RCs were assessed according to their course and distance from the surrounding structures. The relationship between the presence of RC and age, sex, side, and presence of second and third molars was also evaluated. Independent samples t-test, ANOVA, Tukey’s post hoc test, paired t-test, and chi-square were used to compare groups. Results. At least one RC was observed in 22% of the mandibles. Its bilateral incidence was 5.5%. Two major types of canals were detected, namely, type I, following a straight or curved course from the mandibular canal (MC) to the retromolar area (47.3%), and type II, coursing from the retromolar area to the radicular part of the third molar (52.7%). Regarding linear measurements, the mean RC diameter and the mean distance to the MC, second, and third molars were 0.68 ± 0.31, 13.7 ± 2.8, 15.3 ± 3.0, and 7.3 ± 2.3 mm, respectively. Conclusion. Based on the results of this study, RC was found in 22% of the cases; thus, it should be considered as a normal anatomical variation in the Iranian population rather than a rare finding.

scholarly journals Cone Beam Computed Tomographic Analyses of the Position and Course of the Mandibular Canal: Relevance to the Sagittal Split Ramus Osteotomy

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Ahmet Ercan Sekerci ◽  
Halil Sahman
Keyword(s):  
Third Molar ◽  
Mandibular Canal ◽  
Cone Beam ◽  
Sagittal Split Ramus Osteotomy ◽  
Mean Values ◽  
Computed Tomographic ◽  
Dental Patients ◽  
The Third ◽  
Difficult Procedure ◽  
The Mean

Purpose. The aim of this study was to document the position and course of the mandibular canal through the region of the mandibular angle and body in dental patients, using cone beam computed tomographic imaging.Methods. The position and course of the mandibular canal from the region of the third molar to the first molar were measured at five specific locations in the same plane: at three different positions just between the first and second molars; between the second and third molars; and just distal to the third molar.Results. The study sample was composed of 500 hemimandibles from 250 dental patients with a mean age of 26.32. Significant differences were found between genders, distances, and positions. B decreased significantly from the anterior positions to the posterior positions in both females and males. The mean values of S and CB increased significantly from the posterior positions to the anterior positions in both females and males.Conclusion. Because the sagittal split ramus osteotomy is a technically difficult procedure, we hope that the findings of the present study will help the surgeon in choosing the safest surgical technique for the treatment of mandibular deformities.

scholarly journals Panoramic Radiographic Analysis of Signs of Proximity to the Third Molar Roots of the Mandibular Canal in Yemen

2020 ◽  
Keyword(s):  
Third Molar ◽  
Mandibular Canal ◽  
Cross Sectional Study ◽  
Third Molars ◽  
Cross Sectional ◽  
Panoramic Radiographs ◽  
Second Molar ◽  
Female Patients ◽  
The Third ◽  
Dental Clinics

Objectives: The objectives of this study were to assess the relationship between the third molar and the mandibular canal, to identify the radiographic markers most prevalent in predicting connectivity between these structures, and to associate these signs and proximity with the position of the third molar according to Bell, Gregory’s and Winter’s classifications. Subjects and methods: A retrospective cross-sectional study was conducted in the city of Sana’a on a sample of Yemeni patients in Ammar Dental Clinics who underwent panoramic radiography in the year 2019 until September 2020. The study consisted of panoramic radiographs of 597 patients with third molars with a total of 1017 third molars; the number of males was 216 (36.2%) and 381 females (63.8%). The panoramic radiographs were evaluated for proximity signs. Inclusion criteria were patients of both sexes who had at least a fully formed third molar of the mandible that was adjacent to the second molar. The radiographs were excluded if evidence of cystic, neoplastic, or extensive caries processes was detected. Seven radiological signs were used to determine if there was contact between the third molar and the mandibular canal. Results: A proximity to the mandibular canal was verified for 620 (61%) of 1017 third molars. The most frequent radiographic signs of proximity were darkened roots (315 teeth [31%]) and discontinuity of the mandibular canal (267 teeth [26.3%]). Third molar/mandibular canal proximity was found significantly more frequently in female patients and in patients aged 24 years and younger (P < 0.001). The tooth positions most frequently associated with proximity between the third molar and the mandibular canal were position C (highest point of the third molar located at or below the cervical margin of the second molar) and the mesioangular position (long axis of the third molar angled mesially toward the second molar). Conclusions: The frequency of third molar/ mandibular canal proximity was greater in female patients and patients aged 24 years or younger. The most frequently observed signs of proximity were darkening of the roots and discontinuity of the mandibular canal. The tooth positions most frequently associated with proximity of the third molar to the mandibular canal were position C and the mesioangular position.

scholarly journals Radiographic assessment of mandibular canal in Nepalese population: a study based on cone beam computed tomography images

2019 ◽  
Vol 9 (4) ◽  
pp. 52-56
Author(s):  
Pragya Shrestha ◽  
Dil Islam Mansur ◽  
Manoj Humagain ◽  
Sushmit Koju ◽  
Sunima Maskey
Keyword(s):  
Inferior Alveolar Nerve ◽  
Third Molar ◽  
Mandibular Canal ◽  
The Body ◽  
Cone Beam ◽  
Cortical Plate ◽  
Second Molar ◽  
Computed Tomography Images ◽  
Adjacent Structures ◽  
Relationship Of

Background: Mandibular canal runs in the body and ramus of mandible and provides pas­sage for inferior alveolar nerve. Knowledge on spatial relationship of canal with adjacent structures prevent damage to nerve during surgical procedures. This study aims to find three-dimensional relationship of canal as well as its relation with third molar. Methods: This was a cross sectional and retrospective study conducted on Cone Beam Com­puted Tomography images. The relation and position of canal with third molar and position of canal in vertical and horizontal dimensions were analyzed. Results: Mandibular canal was found to be progressively descended in 43% of the canals. The canal was located apical to third molar in 61.9% cases and regarding contact relation, 121(56%) of the third molars had no contact with the canal. Buccal cortical plate was maxi­mum at the level of distal root of second molar and minimum at the level of mesial root of first molar and was reverse for lingual cortical plate. The highest distance between upper border of canal and inferior border of mandible was at mental foramen 13.55±2.27 mm and lowest at mesial root of second molar, 8.72±2.59 mm. Minimum distance between superior border of canal and alveolar crest was distal to second molar (13.78±3.54 mm) and maximum between first molar and second premolar (17.91±3.08 mm). Conclusions: It was observed that canal was interradicularly placed and was by penetrated by third molar in some cases. Thickness of cortical plates varied in various locations buccally and lingually.

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