Dry Human Mandibles Research Articles

Prevalence of Retromolar Foramen in Dry Human Mandibles: A Cross-sectional Study

Introduction: Retromolar foramen present in the retromolar area is related with neurovascular contents, which can be manipulated in surgical procedures. So the knowledge of the presence of foramen is important. In this study, presence of retromolar foramen is identified on dry mandibles. Aim: The aim of the study is to determine the prevalence of the retromolar foramen, its size and shape and the distance of the retromolar foramen from the last socket and the anterior border of mandible and its clinical implications. Materials and Methods: This was a cross-sectional study conducted for a period of three months from September 2019 to November 2019. Forty mandibles were observed on both sides for the presence of the retromolar foramen and its size was measured with a divider and ruler to the nearest millimeters and its shape was observed. The distances of the foramen from last molar socket and also from the anterior border of the mandible were measured with a divider and ruler to the nearest millimeters. Results: Among the 80 sides, on 9 sides (11.25%) retromolar foramen was found: 5 (6.25%) on right side, 2 (2.5%) on left side and 1 (1.25%) bilaterally. Conclusion: According to the present study retromolar foramen can be sometimes observed in mandibles. For surgical and anaesthetical procedures in the retromolar area, retromolar foramen is considered as the neurovascular bundle passing through it.

Study of the Accessory Mandibular Foramina in Dry Adult Human Mandibles and their Clinical and Surgical Implications

Introduction: Accessory Mandibular Foramina (AMF) are most commonly located around the mandibular foramen in the ramus of the mandible. They may transmit the branches of the inferior alveolar nerve and vessels, which may lead to the failure to achieve the inferior alveolar nerve block during various dental procedures. Aim: To evaluate the incidence, the site/location and the number of the AMF in the dry adult human mandibles. Materials and Methods: This was a cross-sectional study. A total of 140 dry adult human mandibles were studied in Parul Institute of Medical Sciences and Research, Parul University, Vadodara for the presence of the AMF with respect to their incidence, number, site/location around the mandibular foramen from December 2018 to July 2020. The findings were recorded, tabulated,analysed and stated using descriptive statistics. Results: The AMF were present in 44 (31.42%), out of 140 dry human mandibles. In 26 (18.57%) mandibles, they were present bilaterally and in 18 (12.85%) mandibles they were present unilaterally; eight (5.71%) on the right side while 10 (7.14%) on the left side. In 62 (77.5%) left and right sides of the mandibles, they were present above the mandibular foramen while in 18 (22.5%) left and right sides, they were present below the mandibular foramen. A single AMF was present in 66 (82.5%) left and right sides of the mandibles. Two foramina were present in the 12 (15%) left and right sides of the mandible. Triple foramina were observed in the two (2.5%) sides of the mandibles. Conclusion: Knowledge of the presence of the AMF can help to prevent the neurovascular complications during various procedures involving mandibular ramus.

Accuracy of maxillofacial prototypes fabricated by different 3-dimensional printing technologies using multi-slice and cone-beam computed tomography.

PurposeThis study aimed to compare the accuracy of 3-dimensional (3D) printed models derived from multidetector computed tomography (MDCT) and cone-beam computed tomography (CBCT) systems with different fields of view (FOVs).Materials and MethodsFive human dry mandibles were used to assess the accuracy of reconstructions of anatomical landmarks, bone defects, and intra-socket dimensions by 3D printers. The measurements were made on dry mandibles using a digital caliper (gold standard). The mandibles then underwent MDCT imaging. In addition, CBCT images were obtained using Cranex 3D and NewTom 3G scanners with 2 different FOVs. The images were transferred to two 3D printers, and the digital light processing (DLP) and fused deposition modeling (FDM) techniques were used to fabricate the 3D models, respectively. The same measurements were also made on the fabricated prototypes. The values measured on the 3D models were compared with the actual values, and the differences were analyzed using the paired t-test.ResultsThe landmarks measured on prototypes fabricated using the FDM and DLP techniques based on all 4 imaging systems showed differences from the gold standard. No significant differences were noted between the FDM and DLP techniques.ConclusionThe 3D printers were reliable systems for maxillofacial reconstruction. In this study, scanners with smaller voxels had the highest precision, and the DLP printer showed higher accuracy in reconstructing the maxillofacial landmarks. It seemed that 3D reconstructions of the anterior region were overestimated, while the reconstructions of intra-socket dimensions and implant holes were slightly underestimated.

Study of mandibular foramen from different bony landmarks in dry human mandibles

Mandibular foramen is an irregular foramen located just above the center of the medial surface of the ramus of the mandible. Mandibular foramen is leading to mandibular canal through which inferior alveolar nerve and vessels will transmit and supply the teeth of lower jaw.1 The inferior alveolar nerve block is the commonest local anesthetic technique which is used for anaesthetizing the lower jaw in various surgical & dental operations on the mandible and mandibular teeth such as removal of impaction, reductions of fractures and extraction of teeth. The success of this technique highly depends on the proximity of the needle tip to the MF at the time of the anesthetic injection. The aim of the study was to find exact location of mandibular foramen from different anatomical landmark. In present study we took 60 dry human mandibles & all the distances were measured from center of mandible to different landmark on both sides. The mean of MF-AB distance on right side is 15.6mm & on left side is 15.3mm. Mean of MF-PB distance are 12.0mm & 11.0mm on right side and left side respectively. MF-MB distance 23.4 mm and 22.9 mm are the mean of MF-MN on right and left side respectively. The mean of MF-AG is 23.2mm on right side & 24.2mm on left side. There is great variation found in the position of MF in previous studies. The present study helps in dental anaesthesia and also would help dental surgeons to avoid complications. Keywords: Mandibular foramen, Landmark, Inferior alveolar nerve distance.

Comparison of Cone Beam Computed Tomography and Digital Radiography in Detecting Separated Endodontic Files and Strip Perforation

The separation of endodontic files and strip perforation are among procedural intraoperative complications which may ultimately lead to the failure of root canal treatment. The aim of the present study was to compare the diagnostic potential of cone beam computed tomography (CBCT) and digital periapical radiographs in detecting separated rotary files and strip perforation in filled canals. Fifty human mandibular molars were selected for this study. The teeth were randomly divided into two groups based on endodontic errors (i.e., file separation and strip perforation). In each group, 25 of 50 mesial canals were randomly chosen for simulating the errors, while the other 25 canals were considered as the control group. In group one, a simulation of the separation of rotary files was performed using ProTaper F2 files. Strip perforation of the root canals in group two was achieved by number 2 and 3 Gates Glidden drills in the coronal third of the root canals. Digital periapical radiographs in two different horizontal angles and high-resolution CBCT scans were obtained from the teeth mounted on a dry human mandible with simulated soft tissue covering. Three experienced observers who were unaware of the study groups evaluated the digital periapical and CBCT image sets in two separate readings. Intraobserver and interobserver agreements, as well as accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), were calculated and compared. Intraobserver and interobserver agreements ranged from poor to excellent and poor to good, respectively. The accuracy, sensitivity, specificity, PPV, and NPV for digital radiography in detecting separated files were 0.950, 0.813, 0.957, 0.929, and 0.880, respectively. The same values for CBCT were 0.747, 0.667, 0.900, 0.833, and 0.783, respectively. For the diagnosis of strip perforation, these values were 0.855, 0.800, 0.909, 0.889, and 0.833 for periapical radiography and 0.955, 1.000, 0.920, 0.926, and 1.000 for CBCT. In conclusion, CBCT was superior for diagnosing strip perforation of the filled root canals, while digital periapical radiographs performed better in the detection of separated rotary files.

The Study of Location of Mandibular Foramen in Dry Adult Human Mandible

Human mandible is only a movable bone forms lower jaw of the skull. It articulates with the temporal boneat the synovial temporomandibular joint, Mandible consists of a horizontal horse shoe shaped body and twobroad rami projecting upward from the posterior end of body. Each ramus of mandible presents two surfaces,external and internal. The aim of the study is to identify the location of mandibular foramen in relationto the limits of mandibular ramus and to correlate the data with the other research works. In the presentstudy 200 dry adult human mandibles of unknown sex and age were collected from the Dept. of Anatomy,J.N.M.C. Sawangi (M) Wardha, DMIMS (DU) and the students of first M.B.B.S of J.N.M.C. Sawangi (M),Wardha, Maharashtra and various measurements were noted. According to the results of the study, it isconcluded that there is variability of the mandibular foramen of the two mandibular rami in the same person.There is variable difference between the locations of mandibular foramen in the dry human mandibles ofthe same zone. It may be due to differences in the age, sex and development in population. This study ismainly concentrated on finding the location of mandibular foramen by measuring its distance from variouslandmarks on mandibular ramus.

Comparison of intraoral digital radiography and cone-beam computed tomography in the measurement of periodontal bone defects.

Periodontal disease has a high prevalence in many countries. Thus, the early detection of periodontal disease is important in order to obtain the most appropriate treatment plan to prevent tooth loss, and subsequently, to maintain the patient's general health. The aim of this study was to compare the accuracy of cone-beam computed tomography (CBCT) and intraoral parallel digital radiography in measuring the dimensions of periodontal bone defects. In this in vitro study, 236 periodontal bone defects were artificially created in dry human mandibles using a burr. Defects included horizontal, one-, two-, and three-wall defects, craters, dehiscences, and fenestrations. Intraoral digital radiographs were obtained using the parallel technique with photostimulable phosphor plates (PSP) and CBCT scans were performed. Two calibrated observers evaluated the images and measured the dimensions of the defects. Clinical probing was performed and considered as the gold standard. The measurements of digital radiography and CBCT were compared to those achieved by probing to evaluate their accuracy. Cone-beam computed tomography had a significantly stronger correlation with the gold standard than intraoral parallel digital imaging. In the total assessment of the periodontal defects, the intraclass correlation coefficient (ICC) was calculated at 0.93 for CBCT-probe and at 0.78 for PSP-probe (p < 0.05). The accuracy of CBCT was superior to that of intraoral digital radiography for measuring horizontal, one-, two-, and three-wall defects, craters, dehiscences, and fenestrations.

Linear measurement accuracy of CBCT panoramic reconstructions: experimental study with dry human mandibles.

Studies on software accuracy of reformatted panoramic computed tomography (CT) images are scarce. The aim of this study was to evaluate the softwareaccuracy of reformatted panoramic views from cone-beam computed tomography (CBCT). Ten dry mandibles were scanned using CBCT with different voxel sizes. Following the reconstruction of panoramic views with three different software, horizontal and vertical linear measurements were performed using the electronic rules of each software. Measurements of the corresponding dry mandibles were taken with a digital caliper and defined as the gold standard. There were no statistically significant differences in linear distances among the dry mandibles and reformatted panoramic CT views. The relative error ranged from 1.3 to 8.0%, depending on the software and voxel size. The linear measurements on reformatted panoramic views are reliable.

Low-dose cone-beam computed tomography in simulated condylar erosion detection: a diagnostic accuracy study.

The purpose of the present study was to assess the diagnostic accuracy of low-dose cone-beam computed tomography (CBCT) in the detection of simulated mandibular condyle erosions. 102 simulated erosions were performed on the condyles of eight dry human mandibles. Each mandible was subjected to four CBCT scan protocols: high-definition (HD), normal definition (NORM), ultra-low-dose high-definition (ULD-HD), and ultra-low-dose normal definition (ULD-NORM). All scans were analyzed by two observers. The inter-observer and intra-observer agreement as well as the agreement with the gold standard were assessed. The sensitivity, specificity, positive-predictive value, negative-predictive value and accuracy of erosion detection were calculated. A substantial to almost perfect agreement with the gold standard was found regarding the HD protocol and substantial agreement in NORM and ULD-HD protocols; however, moderate agreement was found regarding the ULD-NORM protocol. The sensitivity, specificity and accuracy values were highest for the HD protocol followed by the NORM and ULD-HD which showed comparable results; while, the ULD-NORM protocol showed the least values. The studied ULD-HD CBCT protocol can be recommended for the detection of mandibular condylar erosions due to the reduced radiation dose; however, ULD-NORM is not advocated for similar clinical use.

DICOM segmentation and STL creation for 3D printing: a process and software package comparison for osseous anatomy

BackgroundExtracting and three-dimensional (3D) printing an organ in a region of interest in DICOM images typically calls for segmentation as a first step in support of 3D printing. The DICOM images are not exported to STL data immediately, but segmentation masks are exported to STL models. After primary and secondary processing, including noise removal and hole correction, the STL data can be 3D printed. The quality of the 3D model is directly related to the quality of the STL data. This study focuses and reports on the DICOM to STL segmentation performance for nine software packages.MethodsMultidetector row CT scanning was performed on a dry human mandible with two 10-mm-diameter bearing balls as a phantom. The DICOM image file was then segmented and exported to an STL file using nine different commercial/open-source software packages. Once the STL models were created, the data (file) properties and the size and volume of each file were measured, and differences across the software packages were noted. Additionally, to evaluate differences between the shapes of the STL models by software package, each pair of STL models was superimposed, with the observed differences between their shapes characterized as the shape error.Results: The data (file) size of the STL file and the number of triangles that constitute each STL model were different across all software packages, but no statistically significant differences were found across software packages. The created ball STL model expanded in the X-, Y-, and Z-axis directions, with the length in the Z-axis direction (body axis direction) being slightly longer than that in the other directions. The mean shape error between software packages of the mandibular STL model was 0.11 mm, but there was no statistically significant difference between them.ConclusionsOur results revealed that there are some differences between the software packages that perform the segmentation and STL creation of the DICOM image data. In particular, the features of each software package appeared in the fine and thin areas of the osseous structures. When using these software packages, it is necessary to understand the characteristics of each.

Effect of CBCT dose reduction on the mandibular canal visibility: ex vivo comparative study.

To compare the difference in mandibular canal (MC) visibility using three different cone beam computed tomography (CBCT) acquisition protocols: high resolution (HR), standard resolution (ST) and Quick scan+ (QS+). Twenty-five human dry mandibles were scanned by one CBCT machine; i-CAT FLX (Imaging Sciences International, Hatfield, PA, USA), using three different acquisition protocols: high-resolution (HR), standard (ST) and Quick scan+ (QS+). DICOM data were transferred to a third party software Ondemand 3D (Cybermed Co., Seoul, Korea). The fusion module was used to superimpose images derived from different acquisition protocols to standardize the areas to compare the MC visibility. Comparison was performed at nine selected cross sections extending from an area distal to the third molar posteriorly to the first premolar anteriorly. Two expert radiologists evaluated the degree of MC visibility using five-scale scoring system. There was a statistically significant difference between the three acquisition protocols (HR, ST, QS+) at all investigated areas regardless of dentition status (p value < 0.001-0.034) except at the MR1M area where there was no statistically significant difference (p value = 0.094). HR protocol showed the highest prevalence of fully and partially corticated MCat almost all investigated areas while QS+ protocol showed the highest prevalence of invisible MC and clear and unclear non-corticated MC at almost all investigated areas. QS+ protocol of i-CAT FLX CBCT machine is a recommended low-dose CBCT acquisition protocol for MC visibility at dentulous posterior mandibular regions while ST protocol is recommended at edentulous areas.

Contrast-to-noise ratios of different dental restorative materials: an in-vitro cone beam computed tomography study.

In radiological views, strong beam hardening and streaking artifacts occur due to high-density structures and polyenergetic X-ray beams, and these lead to misdiagnosis. This study was performed in vitro to compare the contrast-to-noise ratio (CNR) of commonly used dental restorative materials by using Cone Beam Computed Tomography (CBCT) images with and without artifact reduction (AR) mode. A total of 108 molar teeth were restored with nine different groups of restorative materials, with each group containing 12 teeth. Teeth were placed in a dry human mandible and scanned, one by one, via Planmeca 3D ProMax (Planmeca, Helsinki, Finland) with and without AR mode. Images were analyzed using ImageJ software (National Institutes of Health, Bethesda, MD) to calculate the CNR. CNR was calculated to be the highest in compomer (Glassiosite) images without AR mode (mean: 3.36) and with AR mode (mean: 3.61). CNR was calculated to be the lowest in amalgam (Tytin) images without AR mode (mean: 0.21) and with AR mode (mean: 0.23). A significant difference was found between materials in terms of CNR measurements (p ≤ 0.05). CNR measurements were increased after the AR mode application (p ≤ 0.05). AR mode was effective in reducing artifacts arising from dental materials on CBCT images, so it is necessary to use AR mode for correct diagnoses.

Artifacts of Titanium, Zirconium, and Binary Titanium-Zirconium Abutments in Compute Tomography, Cone Beam Computed Tomography, and Magnetic Resonance Imaging

Aim: The aim of this in vitro study was to evaluate imaging artifacts induced by Titanium, Zirconium, Titanium-Zirconium abutments in CT, MRI and CBCT imaging modalities.Methods: A 4×8mm titanium fixture was inserted in a dry human mandible. Titanium, Zirconium and Titanium–Zirconium abutments measuring 10.5 mm in height are located on the fixture, one by one. Each abutment was scanned 4 times by each imaging modality. Gray value of the images was evaluated in four determined regions adjacent to distal, mesial, buccal and lingual aspects of the implant as the region of interest (ROI) by two observers using image J software. Gray value differences (∆GV) between the control (fixture without abutment) and case images (fixture and each type of abutments) were calculated. Data evaluation was done by analysis of variance and Post Hoc tests.Results: In CBCT, ∆GV was significantly higher in zirconium-titanium images comparing with titanium abutments. (P Value < 0.05)In distal, mesial and buccal aspects of ROI in CT, ∆GV was higher in zirconium images comparing with titanium abutments.In MRI, ∆GV for zirconium were lower than titanium-zirconium and titanium samples, respectively. Also, no significant differences in ∆GV were seen between T1 and T2 protocols, for all samples. Conclusion: In MRI, image artifacts are the least around Zirconium abutments, while in CT and CBCT, titanium abutments produced the least amount of artifacts.

Analysis of angle of mandible in dry human mandibles

Analysis of angle of mandible in dry human mandibles

Comparison between different cone-beam computed tomography devices in the detection of mechanically simulated peri-implant bone defects.

PurposeThis study compared 2 cone-beam computed tomography (CBCT) systems in the detection of mechanically simulated peri-implant buccal bone defects in dry human mandibles.Materials and MethodsTwenty-four implants were placed in 7 dry human mandibles. Peri-implant bone defects were created in the buccal plates of 16 implants using spherical burs. All mandibles were scanned using 2 CBCT systems with their commonly used acquisition protocols: i-CAT Gendex CB-500 (Imaging Sciences, Hatfield, PA, USA; field of view [FOV], 8 cm×8 cm; voxel size, 0.125 mm; 120 kVp; 5 mA; 23 s) and Orthopantomograph OP300 (Intrumentarium, Tuusula, Finland; FOV, 6 cm×8 cm; voxel size, 0.085 mm; 90 kVp; 6.3 mA; 13 s). Two oral and maxillofacial radiologists assessed the CBCT images for the presence of a defect and measured the depth of the bone defects. Diagnostic performance was compared in terms of the area under the curve (AUC), accuracy, sensitivity, specificity, and intraclass correlation coefficient.ResultsHigh intraobserver and interobserver agreement was found (P<0.05). The OP300 showed slightly better diagnostic performance and higher detection rates than the CB-500 (AUC, 0.56±0.03), with a mean accuracy of 75.0%, sensitivity of 81.2%, and specificity of 62.5%. Higher contrast was observed with the CB-500, whereas the OP300 formed more artifacts.ConclusionWithin the limitations of this study, the present results suggest that the choice of CBCT systems with their respective commonly used acquisition protocols does not significantly affect diagnostic performance in detecting and measuring buccal peri-implant bone loss.

Study of mandibular foramen in relation to various landmarks on ramus of mandible along with its clinical significance in people of Gujarat region

Introduction: Mandibular foramen has its clinical importance in giving inferior alveolar nerve block very commonly give n in various dental procedures like removal of third molar tooth, Dental pain, Dentoalveolar trauma, Dry socket, Periapical abscess and in painful procedure on mandible or lower lip/chin. So it is very essential to know the anatomy of mandible particularly mandibular foramen which is situated just above the centre of the medial surface of the ramus of the mandibl e. Mandibular foramen gives passage to inferior nerve and vessels to sup ply the teeth of lower jaw. Mandibular foramen provides an important anatomical land mark. The inferior nerve block is the commonest local anaesthetic technique in clinical practice in dental procedures. There are chances of failure of Inferior alveolar nerve block failure due to its variations in position of. So it requires detailed anatomical study of mandibular foramen. This study aims to determine the exact position of mandibular foramen in relation to various landmark on mandible. We have studied dry adult human mandibles of people of Gujarat region. Materials and Methods: The material for the present study includes 100 adult dry human mandibles of unknown sex. These were collected from Govt. Medical College, Bhavnagar. All measurements were recorded using a sliding vernier caliper. Measurements were taken using below mentioned bony landmarks on the mandible. Results: The study shows mean distance of mandibular foramen to anterior border of ramus 17.052.70mm on right side and 17.353.00mm on left side, to posterior border of ramus was 10.412.13mm on right side and 9.722.06 mm on left side, to mandibular notch 21.502.81mm on right side and 21.883.31 mm on left side, base of man dible or inferior border was 22.203.28 mm on right side and 25.304.2mm on left side. Conclusion: The present study gives knowledge of the position of mandibular foramen and provides useful information for successful local anaesthesia (inferi

Morphological analysis of mandibular foramen through anatomical planes: implications for inferior alveolar nerve block

Error in localization of mandibular foramen is attributed to a high failure rate of inferior alveolar nerve block in clinical dentistry. We hypothesized that a remodelled approach towards exploring the morphology of mandibular foramen would be useful. In the present study, the location of the mandibular foramen was analysed with respect to the anatomical planes across the ramus of the mandible and also with respect to the quadrants on the medial surface of ramus of mandible. The study was conducted on 50 dry human mandibles of unknown age and sex. The anatomical planes were defined and drawn on the mandibles. Measurements were made with digital Vernier callipers and findings were noted. It was observed that the most consistent position of the mandibular foramen was along the vertical plane, however, the foramen was most likely to be localized along the oblique plane. Morphological analysis of the foramen with respect to the anatomical planes as well as the quadrants on the medial surface of ramus led to the analysis that occlusion plane should be the preferred plane of approach. Moreover, a rectangular area on the medial surface of the ramus was identified posterior to the mid-point of occlusion plane (8mm above mid-point, 6mm below mid-point and 6mm behind mid-point) where the incidence of location of the foramen was significantly high. The findings of this study may potentially reduce the failure rate of inferior alveolar nerve block and clinical complications thereof.

Morphometric Analysis of the Mandibular Foramen from Different Bony Landmarks in Dry Human Mandibles

Morphometric Analysis of the Mandibular Foramen from Different Bony Landmarks in Dry Human Mandibles

Morphometric Analysis of the Mental Foramen from Bony Landmarks in Dry Human Mandibles

Morphometric Analysis of the Mental Foramen from Bony Landmarks in Dry Human Mandibles

STUDY OF THE SIZE OF THE CORONOID PROCESS OF MANDIBULE

The mandible serves as an important structure in relation to mastication as all the muscles of mastication are attached to it. The Coronoid process is the anterior bony projected part of ramus of mandible giving attachment to two important muscles of mastication. The aim of our study was to observe the variation in the size of coronoid process in relation to its side (laterality), shape, age and sex. The material for this study comprised of 80 (160 sides) dry human mandibles. The age and sex differentiating criteria were detailed in materials and methods. The size of coronoid process was found to be approximately 1.5 mm longer on the right side than on the left side; 0.01 mm longer in males than females and 0.01 mm longer in dentulous than in edentulous. Triangular coronoid process was found to be the longest followed by round and then hook shaped. Male hormonal impact on muscle growth, bone remodeling and psychology probably lead to enhanced functional stress on mandible due to mastication as compared to that in females. Pterygoid muscles are involved mainly in side to side movement and Masseter-Temporalis (M-T) component in the robust vertical thrust during mastication for crushing. The condyloid process is for pterygoid and M-T-Coronoid Lever complex engenders the proportionate sexual dimorphism as observed in this study. Poor crushing activity in the edentulous is also corroborated in our observation.This comparative study is a pioneer study which will be beneficial for the Anthropologists, Forensic scientists and Reconstructive surgeons.