scholarly journals A CBCT Based Three-Dimensional Assessment of Mandibular Posterior Region for Evaluating the Possibility of Bypassing the Inferior Alveolar Nerve While Placing Dental Implants

Diagnostics ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 406 ◽  
Author(s):  
Mohammed G. Sghaireen ◽  
Kumar Chandan Srivastava ◽  
Deepti Shrivastava ◽  
Kiran Kumar Ganji ◽  
Santosh R. Patil ◽  
...  

A high rate of nerve injury and related consequences are seen during implant placement in the posterior mandibular arch. An approach has been proposed to avoid nerve injury by dodging the inferior alveolar nerve (IAN) while placing an implant. A prospective study with a total of 240 CBCT (cone beam computed tomography) images of patients with three dentate statuses, namely, edentulous (group I), partially edentulous (group II) and dentate (group III) were included in the study. The nerve path tracing was done on CBCT images with On-demand 3D software. The three dimensions, i.e., the linear distance from the outer buccal cortical plate to the inferior alveolar nerve (BCPN), linear distance from the outer lingual cortical plate to the inferior alveolar nerve (LCPN) and linear distance from the midpoint of the alveolar crest to the inferior alveolar nerve (ACN) were assessed. The data were presented and analyzed between variables using one-way ANOVA and independent t-test in SPSS version 21.LCPN of the right 1st premolar region (p < 0.05) was significantly different among the groups with edentulous subjects recorded with the minimum value (6.50 ± 1.20 mm). Females were found to have significantly (p < 0.05) less available bone (6.03 ± 1.46 mm) on the right side of the mandibular jaw compared to males in edentulous group of patients. On comparing age groups for partially edentulous subjects, LCPN of the right 1st premolar region had significantly (p < 0.05) less available bone (6.03 ± 0.38 mm) in subjects with age ≥54 years. The IAN follows a lingual course in the molar region and later flips to the buccal side in the premolar region. The LCPN dimension in the 1st and 2nd premolar region was found to be more than 6 mm irrespective of age, gender and side of the jaw. Thus, it can be considered as a suitable site for placing implants while bypassing the IAN with CBCT assessment remaining as the mainstay in the pre-surgical phase.

2020 ◽  
Author(s):  
Gui Chen ◽  
Mona Al Awadi ◽  
David William Chambers ◽  
Manuel O Lagravère-Vich ◽  
Tianmin Xu ◽  
...  

Abstract Background: With the aid of implants, Björk identified the two-dimensional mandibular stable structures in cephalogram during facial growth. However, we don't know the three-dimensional stable structures exactly. The purpose of this study was to identify the most stable mandibular landmarks in growing patients using three-dimensional images.Methods: The sample was comprised of two cone-beam computed tomography (CBCT) scans taken about 4.6 years apart in 20 growing patients between the ages of 12.5 (T1) to 17.1 years (T2). After head orientation, landmarks were located on the chin (Pog), internal symphysis (Points C, D and E), and mandibular canals, which included the mental foramina (MF and MFA) and mandibular foramina (MdF). The linear distance change between Point C and these landmarks was measured on each CBCT to test stability through time. The reliability of the suggested stable landmarks was also evaluated. Results: The total distance changes between Point C and points D, E, Pog, MF, and MFA were all less than 1.0 mm from T1 to T2. The reliability measures of these landmarks, which were measured by the Cronbach alpha, were above 0.94 in all three dimensions for each landmark. From T1 to T2, distance changes from Point C to the right and left mandibular foramina were respectively 3.39±3.29 mm and 3.03±2.83 mm. Conclusions: During a growth period that averaged 4.6-years, ranging from 11.2 to 19.8 years, the structures that appeared relatively stable and could be used in mandibular regional superimposition included Pog, landmarks on the inferior part of the internal symphysis, and the mental foramen. The centers of the mandibular foramina, the starting points of the mandibular canal, underwent significant changes in the transverse and sagittal dimensions.


2020 ◽  
Vol 90 (4) ◽  
pp. 539-547 ◽  
Author(s):  
Eman H. Elabbassy ◽  
Noha E. Sabet ◽  
Islam T. Hassan ◽  
Dina H. Elghoul ◽  
Marwa A. Elkassaby

ABSTRACT Objectives To assess the effectiveness of bone-anchored maxillary protraction (BAMP) in patients with unilateral cleft lip and palate (UCLP) and whether it was enhanced when preceded by maxillary expansion. Materials and Methods The sample consisted of 28 growing children (9–13 years old) with UCLP and Class III malocclusion. They were divided into two equal groups. In group I, patients were treated with BAMP not preceded by maxillary expansion. In group II, patients were treated with BAMP preceded by maxillary expansion. To assess treatment changes in three dimensions, Cone-beam computed tomography images were taken 1 week after surgical placement of the miniplates (T1) and after 9 months of treatment (T2). Results BAMP produced forward movement of the maxilla in both groups (3.17 mm) and (3.37 mm) respectively, without significant differences between the two groups except for clockwise rotation of the palatal plane in group I (1.60). Conclusions BAMP is an effective treatment modality for correcting midface deficiency in patients with UCLP whether or not maxillary expansion was carried out.


2012 ◽  
Vol 91 (7) ◽  
pp. 659-665 ◽  
Author(s):  
H. Long ◽  
Y. Zhou ◽  
L. Liao ◽  
U. Pyakurel ◽  
Y. Wang ◽  
...  

The objective of this systematic review was to compare the outcomes between coronectomy and total removal for third molar extractions with high risk of nerve injury and to help practitioners make prudent decisions on whether and how third molars should be removed. PubMed, Embase, Web of Science, CENTRAL, and SIGLE were searched from January 1990 to October 2011 for randomized or non-randomized controlled trials. Four studies met our inclusion criteria. The pooled risk ratio (coronectomy vs. total removal) was 0.11 (95% CI = 0.03-0.36), 1.03 (95% CI = 0.54-1.98), 0.55 (95% CI = 0.28-1.05), and 1.14 (95% CI = 0.57-2.30) for inferior alveolar nerve injury, post-operative infection, dry socket, and pain at 1 wk after surgery, respectively. A relatively high rate of failed coronectomy in one study (38.3%, compared with 2.3%-9.4% in others) may be attributed to a higher proportion of narrowing roots and vertical impactions. Although root migration rate was high (13.2%-85.29%), the migration distances were short (3.06 ± 1.67 mm), and the directions were away from the nerves. Moreover, the rates of re-operation and root exposure were low. Therefore, coronectomy appears superior to total removal for reducing inferior alveolar nerve damage and could be used in clinical practice for third molar extractions with high risk of nerve injury.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Tatyana Vladimirova ◽  
Lyubov Aizenshtadt ◽  
Mikhail Davydkin-Gogel

Objective: justifying the possibility of using frequency-based hearing research via the web application ‘Automated System for Initial Hearing Assessment’. Materials and methods. The study was carried out at the Department of Otorhinolaryngology of the Samara State Medical University clinics in October 2019. It involved 91 patients 17 to 73 years old (average age 48±14.6 years). All study participants were divided into two age groups: Group I 17-59 years old), and Group II (over 60 years old). Patients were required to undergo two hearing assessment tests: using the Interacoustics AC-40 clinical audiometer and using our web application ‘Automated System for Initial Hearing Assessment’ (patent No. 2019664671). Results. The maximum difference in average hearing thresholds between pure-tone threshold audiometry and the web application in Group I was 3.3 dB at a frequency of 2 kHz on the right and 3.2 dB at frequencies of 2 and 4 kHz on the left; in Group II, it constituted 4.7 and 3.5 dB at 1 and 2 kHz, on the right, correspondingly, and 7.2 dB at 4 kHz on the left. The presented data were evaluated using the Cohen’s kappa coefficient, which confirmed high level of agreement between the results obtained using the clinical audiometer vs. our original web application. Conclusion. Based on the obtained results, a conclusion was made about the possibility of using the original web application for the initial hearing express assessment in general practice in conditions of limited availability of audiological care.


2021 ◽  
Vol 6 (2) ◽  
pp. 4-7
Author(s):  
Nuriya I. Murtazina ◽  
Elena D. Lutsai ◽  
Sofya V. Ershova

Objectives to determine the thyroid gland growth rate in the intermediate fetal period of human ontogenesis. Material and methods. The thyroid glands of 60 male and female fetuses aged from 14 to 27 weeks were the subject of this research. The material was divided according to fetus age in three groups: Group I from 14 to 18 weeks, Group II from 19 to 22 weeks and Group III from 23 to 27 weeks. Results. The study revealed the increase in all dimensions of thyroid gland related to the increase of fetus age. During the intermediate fetal period of ontogenesis, the growth varied from 19% (for the anteroposterior isthmus size) to 59% (for the right lobe height). The thyroid gland growth rate for different sex groups varied between 24% and 60% in female fetuses, in male fetuses from 20% to 57%. Besides, the thyroid lobes and isthmus of female fetuses grew at a higher rate than those of the male fetuses. The uneven growth of the anatomical structure was also registered when comparing different age groups within the intermediate fetal period. The highest rate of thyroid gland growth was observed starting from the 22nd week of fetal life; until the 19th week the growth rate ranged between 7% (isthmus) and 25% (right lobe). The study of the thyroid gland growth rate in female and male fetuses in different age groups revealed identical tendencies involving the active growth of thyroid gland dimensions starting from the 22nd week.


2021 ◽  
Vol 28 (4) ◽  
pp. 68-72
Author(s):  
Anatoly A. Balandin ◽  
Lev M. Zheleznov ◽  
Irina A. Balandina ◽  
Valery S. Shelud'ko

Investigation which devoted to the study of the age characteristics of the human body are becoming increasingly important. Magnetic resonance tomography is the most informative diagnostic method for intravital visualization of tissues and structures of the brain. It also allows you to more accurately see the picture of morphological features with age-associated changes. The aim of the study was to carry out a comparative analysis of the age-related morphometric characteristics of the cerebellum in male with mesocranic type of cranium in young and old age according to the data of magnetic resonance tomography. The analysis of the results of a morphometric study of the cerebellum on tomograms of 91 men examined for medical reasons was carried out. Depending on the age, the subjects were divided into two groups. Group I included 52 young men (22–27 years old, inclusive), group II included 39 elderly men (from 78 to 83 years old, inclusive). The transverse, longitudinal and vertical dimensions of the cerebellum were determined. When comparing the parameters of the linear dimensions of the cerebellum in the studied age groups of men, a statistically significant decrease in all indicators in old age compared with young age was revealed (p=0.042). There was no statistically significant difference between the parameters of the longitudinal and vertical sizes of the cerebellar hemispheres in individuals of each age group (p>0.05); there is a tendency for these sizes to prevail in the right cerebellar hemisphere. The results obtained can serve as the equivalent of the age-related anatomical norm of the cerebellum in young and old men, which will make it possible to use these data in basic and clinical research, as well as in medical practice.


Author(s):  
Chetan Hegde ◽  
Swapnil Mahade ◽  
Krishna Prasad D.

<strong><em>Background</em>:</strong>Since discrepancy between centric relation and maximum intercuspation has been an area of interest for dental fraternity for decades, the study was conducted to expand the concepts of the same when age is taken into consideration.<p><strong>Objective:</strong> This study was conducted to assess and measure the discrepancy between centric relation (CR) and maximum intercuspation (MI) at right and left condyles in three age groups, compare the discrepancy at right and left condyles between three age groups and right and left side condyles within the same age group.</p><p><strong>Methods:</strong> Sixty healthy subjects were selected and divided into three groups of twenty subjects each. Group I: 18-25 years, Group II: 30-45 years and Group III: more than fifty years. Preliminary impressions were made. Orientation relation was transferred to a semi-adjustable arcon articulator. Subjects were guided into centric relation using Dawson's bimanual manipulation technique and centric interocclusal record was made. The mandibular cast was related to the maxillary cast using centric interocclusal record. The casts were then allowed to fall into maximum intercuspation and the distance that the condylar analogues had moved was measured using Feeler gauge.</p><p><strong><em>Results:</em></strong> The mean CR-MI discrepancy in Group I was 0.417±0.137 mm and 0.364±0.123 mm, Group II was 0.528±0.160 mm and 0.512±0.158 mm and Group III was 0.873±0.228 mm and 0.815±0.172 mm at the right and left condyles respectively.</p><p><strong><em>Conclusion:</em></strong> Within the limitations of the study it was concluded that all the sixty subjects had a CR-MI discrepancy in both left and right condyles. The variation in discrepancy between the three age groups was found to be very highly significant.</p>


Author(s):  
Rakhi Chandak ◽  
Manoj Chandak ◽  
Pranali Thakare ◽  
Ramhari Sathawane ◽  
Runal Bansod ◽  
...  

Aims: To determine the reliability and accuracy of maxillary sinus volume and nasal septum patterns in personal identification in forensics using CBCT (cone beam computed tomography). Study Design: Retrospective Study Place and Duration of Study: Department of Oral Medicine and Radiology, Swargiya Dadasaheb Kalmegh Smruti Dental College and Hospital Nagpur, from September 2019-December 2019. Methodology: 110 CBCT scans of bilateral maxillary sinuses and nasal septum images were retrospectively obtained from the Oral Medicine and Radiology database (68 men and 42 females). The study was divided into two groups based on age. Group -I consists of 58 CBCT scans taken between the ages of 20 and 40, while Group -II consists of 52 CBCT scans taken between the ages of 41 and 80. The height, breadth, and depth of the maxillary sinus were measured linearly. The nasal septum was classed as simple deviation to the right or left, sigmoid type, reverse sigmoid type, and straight based on the septa's deviations. Each person's combined maxillary sinus and nasal septum pattern was documented. Results: The difference in maxillary sinus volume between two age groups was significant (P<0.5). In age group I, there was a substantial change in the left deviation pattern, and there was a significant change in the reverse sigmoid pattern in males and the straight nasal septum pattern in females. With whatever nasal septum configuration, there were no volumetric alterations(P>0.5). Conclusion: In future, further research will be needed with a larger number of images to compare in order to arrive at a definitive identification.


2014 ◽  
Vol 17 (4) ◽  
pp. 74
Author(s):  
Abbas Shokri ◽  
Sepideh Falah-Kooshki ◽  
Jalal Poorolajal ◽  
Atena Karimi ◽  
Farzaneh Ostovarrad

<p><strong>Objective: </strong>Mandibular foramen (MF) is located on the internal surface of the ramus through which blood vessels and nerves pass. Determination of the anatomic position of the MF is very important in inferior alveolar nerve block anesthesia (IANBA), ramus osteotomy and surgical procedures of the posterior angle of mandibular ramus. The aim of this study was to determine anatomic position of the MF using anatomic landmarks on the three dimensional CBCT images. <strong>Material and </strong><strong>Methods: </strong>A total of 103 CBCT images was evaluated. The NNT Viewer software program was used to measure the distances between the lines tangent on the MF periphery and the anterior border of the ramus, the posterior border of the ramus, the inferior border of the mandible, and the coronoid notch in mm by to age and gender. <strong>Results: </strong>The results showed a slight difference in anatomic dimensions between the right and left sides, with no significant differences. The anatomic dimensions of the MF on both sides were a little bigger in males than in females. There were no significant differences in the anatomic dimensions of superior-inferior and anterior-posterior dimensions of the left and right sides in different age groups. <strong>Conclusion: </strong>No significant changes occur in the position of the MF with age. The anatomic differences between males and females should be taken into account during IANBA procedures. Males have bigger jaws than females; therefore, there is a longer distance between the MF and the anatomic landmarks evaluated. </p><p><strong>Keywords</strong>: Mandibular Foramen; Anatomic Landmarks; Cone-Beam Computed Tomography</p>


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Claudio Letta ◽  
Andreas Schweizer ◽  
Philipp Fürnstahl

The purpose of this study was to accurately quantify contralateral differences of the scaphoid in three-dimensional space to evaluate the feasibility of using the healthy contralateral bone as a reconstruction template in the preoperative planning of complex mal- or nonunions. Three-dimensional surface models of the left and right scaphoids were reconstructed from computed tomography images and compared in 26 individuals. Left-right differences were quantified with respect to volume, surface area, length, and surface-to-surface deviation. The average left-right differences in volume, surface area, and length were 95.4 mm3 (SD 66.2 mm3), 32.7 mm2 (SD 22.9 mm32), and 0.28 mm (SD 0.4 mm), respectively. The average surface-to-surface deviation between the sides was 0.26 mm (SD 0.2 mm). High statistical correlation (Pearson) between the left and the right side was found in all evaluated measures.


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