Showing 22 results for Mandibular
F. Heravi , H. Ziaee ,
Volume 12, Issue 3 (10-1999)
Abstract
Lateral and anterior displacements of mandible may cause malocclusion. The aim of this study was to determine the prevalence of these displacements in a population of 597 childrens age 12 in Mashhad secondary schools. Displacment of mandible was shown to be in 11.8 percent of the population (6.2 percent anterior and 5.6 percent lateral displacement).Anterior displacement of mandible was diagnosed in all mandibie lateral displacements. Premature contacts were observed in upper lateral incisors, second premolars and first molar in anterior and lateral displacements, respectively.
Y. Refua , N. Abbas-Zadeh. ,
Volume 14, Issue 2 (8-2001)
Abstract
Different techniques for local anesthesia are used in the mandible. The purpose of this study was to determine the effects of inferior alveolar dental nerve blocks by comparing the two akinosi and conventional techniques. 80 patients (aged 15-60 years old) were randomly divided into tow groups for extracting the mandibuler posterior teeth by akinosi and conventional techniques. Patients were all injected with 1.8 ml of Lidocaine 2% plus Adernaline j^nnnn .Then the Pain Sensation during injection,positive aspiration, beginning time of anesthesia, duration of anesthesia depth of anesthesia, and the anesthesia of soft tissue related to sensory nerves were evaluated. The results showed that the pain sensation in conventional technique was significantly higher than that of akinosi technique. The number of positive aspirations in conventional technique (12,5%) was higher than that of akinosi (5%) but not significantly different. The long buccal nerve anesthesia in akinosi technique (75%) was significantly higher than that of conventional technique. There was no significant difference between the two techniques for the depth of anesthesia. The success rate was 87.5% in conventional technique and 80% in akinosi technique. The average time of lips anesthesia in conventional technique was 3 minutes compared with 4 minutes in akinosi technique, which was not significantly different from each other. However, the beginning time of aneshtesia in tongue was significantly lower in conventional technique. No significant difference in the duration of anesthesia in lips and tonques between the two techniques was observed.
Y. Refoua , S. Jalayer ,
Volume 15, Issue 1 (3-2002)
Abstract
Dept. of Oral and Maxillofacial Surgery, Ghazvin University of Medical Sciences A lot of studies have discussed the reduction of mandibular movements range after orthognatic surgeries. The present study focuses on the conventional orthognatic surgery methods to determine the method with the least effects on mandibular movements. Sixty patients were investigated in a prospective study. They were divided, based on the surgical method, into three groups. In the first group (20 patients) sagital osteotomy, in the second group extra oral vertical osteotomy for mandibular retrusion, and in the third group simultanouse Bimax osteotomies of the upper and lower jaws, were performed. The surgical method applied for maxilla was Lefort 1 osteotmy to protrude the upper jaw and of the lower jaw was extraoral vertical osteotmy. The range of mouth opening, in centrals region, right and left lateral movements and protrusive movements, before and three months after surgery, were measured. Sagital osteotomy method (the first group) showed the most changes and reduction in movements, while the least changes were observed in extraoral vertical method (the second group).
L. Eslamian ,
Volume 15, Issue 4 (1-2003)
Abstract
According to researches, premolar extraction and anterior teeth retraction result in temporomandibular joint disorder due to posterior position of mandible. The aim of this study was to evaluate the effect of premolar extraction on TMJ disorder. In this interventiond study, 4 groups (10 patients for each group) were treated.They were classified as 1- non extraction, 2- extraction of two upper first premolars, 3- extraction of four first premolars, 4- combined extraction groups. Helkimo scores were evaluated before treatment, after treatment, one and two years after treatment. The results were analyzed with ANOVA and paired t-test. At the end of the treatment and two years after treatment in comparison with before treatment, Helkimo score had Significant differentce in all groups (PO.001). In the second year after debanding in comparison with the first year after debanding, no significant differences were seen in each group. No significant difference was seen between the four groups in the final appraisal of TMD. It seems that extraction had no adverse effect on TMD.
M. Tabrizi-Zadeh , K. Farazi ,
Volume 16, Issue 1 (4-2003)
Abstract
Statement of Problem: The main objective of endodontic therapy is chemomechanical cleansing of entire pulp cavity and its complete obturation with an inert material. During this procedure, the failure of detection and inadequate cleaning of a canal will result in failed endodontic therapy. Therefore, the dentist must have enough knowledge of root canal morphology to treat a tooth successfully.
Aim: The aim of this study was to determine the number and type of root canals of mandibular incisor teeth.
Materials and Methods: In order to do this in-vitro, descriptive study, 68 non-carious mandibular incisor teethj collected from different clinics in Yazd, were immersed in indian ink, decalcified and cleared.
Results: It was found that 55.9% of the teeth had two separate canals that in 5.5% of them, the canals merged before' apical foramen. In 4.4% of these samples, two separate canals existed along the whole root.
Conclusion: Considering high percentage of two canals in lower mandibular incisors, during access preparation, more attempts in detection of the second canal, is emphasized.
M.e. Daneshvar ,
Volume 16, Issue 4 (1-2004)
Abstract
Statement of Problem: Pain control is of high importance in dentistry. Prescribing sedatives such a Diazepam, as an anti-depressant and pain threshold elevator drug is able to influence the patient's reaction to pain and reduce it.
Purpose: The aim of the current study was to evaluate the effect of Diazepam in pain reduction following mandibular impacted third molar surgery.
Materials and Methods: In this study, which was conducted in the department of Oral and Maxillofacial surgery Faculty of Dentistry, Tehran University of Medical sciences. The patients were divided into two equal groups (n=30). For controls, antibiotics and analgesics were prescribed after surgery. However, except the aforementioned drugs, Diazepam (5mg), three times per day, was prescribed for the experimental group. The amount of mouth opening was also measured as an auxiliary sign after one week. The data were compared by
X2 test after one week.
Results: 60% of the experimental group and 13.8% of the control group felt a weak pain. Statistically significant differences were observed regarding pain feeling between two groups (P<0.001). Severe pain feeling was 34.5% and 10%, for control and experimental groups, respectively.
Conclusion: It is suggested that Diazepam is an effective pain reduction drug following third molar surgery.This drug has also a relative effect on temporary trismus resulting probably from muscle trauma or pain.
Gh. Shirani , D. Kazemi ,
Volume 16, Issue 4 (1-2004)
Abstract
Statement of Problem:The choung osteotomy (Intraoral Vertico- Sagittal Ramus Osteotomy) has developed since 1992 in the treatment of mandibular prognathism. In IVSRO, osteotomy plane is theoretically parallel to the original sagittal plane and thereby attempting to decrease the incidence of condylar dispacement. This osteotomy designed additionally to decrease neurosensory disturbances.
Purpose: The aim of this study was to evaluate the incidence of neurosensory deficit and condylar displacement with IVSRO and Sagittal Split Ramus Osteotomy (SSRO).
Materials and Methods: In this study, mandibular set back surgery was accomplished upon 7 patients by choung osteotomy. In addition to choung osteotomy, in 2 patients Lefort 1 osteomy was performed for maxillary protrusion and for 2 other patients, chain surgery was performed. Variables such as the neurosensory disturbances of inferior alveolar nerve and condylar displacement following choung osteotomy were investigated. All the patients were followed up one year after osteotomy. OPG, Lateral Cephalogram and Submentovertex radiographies were take pre and postoperatively for all patients.
Results: No statistically significant differences were found in condylar displacement (P>0.5). However, Mc Nemar analysis showed significant difference of neurosensory deficit between IVSRO and SSRO (P=0.001).
Conclusion: It is suggested that choung osteotomy is a safe procedure for mandibular surgery.
As. Madani, B. Ajami ,
Volume 17, Issue 2 (6-2004)
Abstract
Statement of Problem: In recent years, the prevalence of temporomandibular disorders among children and adolescents has increased, however, no study on the correlation between occlusal relations and temporomandibular disorders, in Mashhad adolescents, has been conducted yet.
Purpose: The aim of this study was to survey the relationship between occlusal indices and temporomandibular disorders (TMD) among Mashhad adolescents, with the age range of 11-14 years old.
Methods and Material: In this descriptive cross-sectional study, 1066 students (533 males and 533 females), age ranging from 11-14 years old (12.620.96 years), from seven Mashhad educational regions, were selected. Temporomandibular joints were thoroughly examined for all subjects. All occlusal indices including dentition system, angles classification, types of malooclusion such as cross-bite, deep-bite as well as types of lateral occlusion, premature contacts in lateral and protrusive movements were investigated. Data were analyzed statistically using, Chi-Square and logestic regression tests.
Results: The prevalence of TMD was 23.5%. There was no significant relation between TMD and type of dentition, angles classification and type of occlusion in lateral movements, however, statistically significant relation was found between TMD and deep over bite (P<0.05). Premature contacts in lateral movements at balancing side were proved to be significant etiologic factors of TMD (P=0.003).
Conclusion: In the present study, premature contacts at balancing side and secondary deepbite malocclusion were considered to be the most important etiologic factors of TMD.
S. Nokar , R. Baghaee-Naeeni ,
Volume 17, Issue 3 (8-2004)
Abstract
Statement of Problem: In the treatment of edentulous patients with implant supported fixed partial dentures several factors such as implant numbers, implant position, superstructure pattern and cantilever length must be considered. Mandibular flexture in function exerts forces in peri-implant bone, however this phenomenon has received little attention.
Purpose: The goal of this finite element analysis (FEA) study was to evaluate the effect of mandibular dimensional changes on peri-implant bone stress in different prosthesis and implant treatment plans.
Materials and Methods: In this experimental study, three dimensional finite element computer model of mandible was simulated according to data from CT-Scan in 0.5 mm sections. The model of 4.110 mm ITI implant, measured by profile projector, was simulated in solid works 2003 software. Implant models were inserted, in two different patterns, on mandible and three different superstructures were placed on implants. Two clenching tasks were modeled (incisal clench and right molar clench).
Results: Analysis of Von Misses stress for peri-implant bone revealed the lowest stress values in three-piece superstructure.
Conclusion: According to this study, additional placement of implants in order to fabricate independent prostheses and to achieve the freedom of mandibular flexture are recommended.
T. Hosseinzadeh Nik , M. Habibi , B. Golestan , Hr. Barikani ,
Volume 20, Issue 4 (1-2008)
Abstract
Background and Aim: Chin cup is an orthopedic appliance for treating growing skeletally Cl III patients. The amount of chin forward movement in addition to morphologic changes in bony structure, determines the final profile of treated patients. The aim of this study was to evaluate the amount of morphologic changes of symphysis after chin cup therapy in skeletally Cl III patients.
Materials and Methods: In this clinical trial, twenty eight cephalometries before and after chin cup therapy of 14 skeletally Cl III patients were analyzed. Landmarks introduced by Ricketts were determined to evaluate the symphysis and describe its relation to mandible. َAlso four additional measurements regarding the symphysis individually were evaluated and analyzed. Data were analyzed by paired t and pearson tests with P<0.05 as the level of significance.
Results: The results showed that the height of symphysis increased after treatment (P=0.02), but its depth decreased (P=0.04). The sysmphysis turned down and back.
Conclusion: These findings suggest that in Cl III malocclusions with a prognathic mandible, chin cup therapy creates changes in the horizontal dimension of symphysis morphology, which improves the Cl III profile. If the patient isn't a vertical grower, vertical changes of symphysis would be desirable. In addition, changes in the vertical dimension of the mandible (body and ramus) could be observed as a backward and downward rotation.
H. Bashizadeh Fakhar, F. Abolhasani, T. Mohtavipour,
Volume 21, Issue 1 (10-2008)
Abstract
Background and Aim: Accurate bone measurements are essential to determine the optimal size and length of dental implants. The magnification factor of radiographic images may vary with the imaging technique used. The purpose of this study was to compare the accuracy of linear tomography and panoramic radiography in vertical measurements, as well as the accuracy of linear tomography in mandibular width estimation.
Materials and Methods: In this test evaluation study, the vertical distances between the crest and the superior border of the inferior alveolar canal, marked with a metal ball, was measured by linear tomography and panoramic radiography in 23 sites of four dry mandible bones. Also the mandibular width was measured at the same sites. Then, the bones were sectioned through the marked spots and the radiographic measurements were compared with actual values.
Results: The vertical magnification factor in tomograms and panoramic radiographs was 1.79 (SD=0.17) and 1.69 (SD=0.23), respectively. The horizontal magnification of tomograms was 1.47 (SD=0.17). A significant correlation was found between the linear tomographic and actual values, regarding vertical dimensions (p<0.001, r=0.968) and width (p<0.001, r=0.813). The correlation was significant but lower in panoramic radiographs (p<0.001, r=0.795). Applying the magnification values suggested by the manufacturer, the mean difference of vertical measurements between the tomographic sections was 2.5 mm (SD=3.4) but 3.8 mm (SD=1.65) in panoramic radiographs. The mean of absolute difference in mandibular width between the tomographic sections and reality was 0.3mm (SD=1.13). In the linear tomograms, 4.3% of vertical and 56.5% of the width measurements were in the ±1mm error limit. Only 4.3% of the vertical measurements were within this range in the panthomographs. The linear regression equation between the actual values and those obtained by radiography in vertical dimensions showed that 87.5% of tomograms and 51.8% of panoramics were located in the ±1 mm error limit.
Conclusion: Based on the results of this study, the linear tomography is more accurate than panoramic radiography in mandibular height estimation. The accuracy of linear tomography in width estimation is within acceptable limits.
M. Sahebi, P. Bostani Amlashi,
Volume 23, Issue 3 (12-2010)
Abstract
Background and Aims: Selecting an appropriate treatment plan is one of the most critical aspects of dental treatments. The purpose of this study was to compare multimedia system and conventional method in patients' selecting prosthetic treatment and the time consumed.
Materials and Methods: 90 patients randomly divided into three groups. Patients in group A, once were instructed using the conventional method of dental office and once multimedia system and time was measured in seconds from the beginning of the instruction till the patient had came to decision. The patients were asked about the satisfaction of the method used for them. In group B, patients were only instructed using the conventional method, whereas they were only exposed to soft ware in group C. The data were analyzed with Paired-T-test (in group A) and T-test and Mann-Whitney test (in groups B and C).
Result: There was a significant difference between multimedia system and conventional method in group A and also between groups B and C (P<0.001). In group A and between groups B and C, patient's satisfaction about multimedia system was better. However, in comparison between groups B and C, multimedia system did not have a significant effect in treatment selection score (P=0.08).
Conclusion: Using multimedia system is recommended due to its high ability in giving answers to a large number of patient's questions as well as in terms of marketing.
Mehrdad Panjnoush, Zahra Ghoncheh, Hoda Banihashemi, Farnosh Taghavi,
Volume 24, Issue 4 (1-2012)
Abstract
Background and Aims: Disc displacement is the most common temporomandibular joint disorder and magnetic resonance imaging (MRI) is the gold standard in its diagnosis. This disorder can lead to changes in signal intensity of magnetic resonance (MR). The purpose of this study was evaluation of correlation between relative signal intensity of MR images of retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle with type of anterior disk displacement and condylar head flattening in patients with temporomandibular disorder (TMD).
Materials and Methods: In this retrospective study, 31 MR images of patients who had anterior disc displacement were evaluated. After relative signal intensity measurement for retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle, the correlation between relative signal intensity and type of anterior disc displacement was evaluated with repeated measure ANOVA test. In each of these 3 areas, t-test was used to compare the groups with and without condylar head flattening.
Results: The correlation between relative signal intensity of MR images and type of anterior disc displacement in retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle was not significant. There was also no statistically significant correlation between relative signal intensity of MR images and flattening of condylar head in retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle (P>0.05).
Conclusion: According to findings of this study, relative signal intensity of MR images in retrodiscal tissue, superior and inferior head of ptrygoid muscle is not a good predictor for type of anterior disc displacement and flattening of condylar head. It seems that this cannot be used as a diagnostic marker for TMD progression.
Daryosh Goodarzipour, Allahyari Nezad, Bahareh Purtaji, Yasaman Mohemkar Kheirandish,
Volume 26, Issue 2 (5-2013)
Abstract
Background and Aims: Because of high prevalence of TMJ dysfunctions , increased promotion of diagnostic and treatment methods is necessary. In many cases, in addition to disc position, morphology of other joint components such as articular eminence can be changed and therefore the probable correlation between disc position and morphology of hard tissue components can be used for prediction of internal derangements. The aim of this study was to evaluate the correlation between the position of disc and morphology of articular eminence of TMD`s patients using magnetic resonance imaging (MRI).
Materials and Methods: In this cross sectional study by evaluation of digital MRI files, ultimately 78 joint images were identified which had sufficient quality and resolution for review. Then the MRI images, were observed and evaluated by 3 oral and maxillofacial radiologists to determine the disc position (normal, anterior displacement with and without reduction, and posterior displacement) and morphology of articular eminence (Box, Sigmoid, Flattened). Ultimately the results that were reported at least by 2 observers were included as the final results and were recorded in the check list. Data were analyzed using Chi-Square test and Fisher test.
Results: In this study, no case of posterior disc displacement was found and therefore was excluded from the study. Articular eminence morphology (Flattened versus Sigmoid) showed statistically significant correlation with anterior disc displacement with and without reduction (P-values for anterior displacement with and without reduction were 0.03 and 0.002, respectively). No significant difference was found between the sigmoid and box types in relationship with disc displacement (P-values for anterior displacement with and without reduction were 0.72 and 0.70. In this study, no significant difference between the anterior disc displacement with reduction and anterior disc displacement without reduction in relationship with the morphological changes of articular eminence in any of the cases were found.
Conclusion: The results showed that flattening of articular eminence had significant relationship with anterior disc displacement.
Mehrdad Panjnoosh, Farnoosh Taghavi, Ahmad Reza Shamshiri,
Volume 27, Issue 3 (9-2014)
Abstract
Background and Aims: There is a risk of nerve injury during the extraction of the impacted third molars, in cases with proximity of the inferior alveolar nerve and this tooth. The aim of this study was to evaluate the effect of different various factors on the degree of vulnerability using CBCT (Cone Beam Computed Tomography) imaging technique.
Materials and Methods: CBCT images of 191 patients referred for the exact assessment of the relationship between the mandibular canal and impacted mandibular third molars were selected. The position of these anatomical structures was evaluated at their contact point. The possible effect of gender, impaction form of the third molars, anatomical relationship between the third molars and the mandibular canal and the age differences were studied. Data were analyzed using Chi-square and Student’s t-test.
Results: There was a close relationship between the mandibular canal and impacted third molars in 81.7% of the patients. The contacts were shown to be significantly higher in females than males (P=0.01) and in the cases with the lingually position of the third molar and the mandibular canal (P<0.001). However, the age and impaction form of the teeth did not have a significant influence (P>0.05).
Conclusion: The risk of nerve damage or exposure is increased in females and lingual position of the mandibular canal to the third molar in cases with higher proximity between these 2 structures in panoramic radiographs using CBCT images. Therefore, the surgeon must pay enough attention in these cases of third molar extraction.
Sahebi Majid , Hajizadeh Moslem ,
Volume 27, Issue 4 (1-2015)
Abstract
Background and Aims: Temporomandibular joint disorders are common problems among patients referring to dental schools and clinics. However appropriate treatment modalities are performed for the TMD patients in dental school, the results and success rate of these treatments are not studied distinctly. The aims of this study was to determine the treatment performed for temporomandibular patients at the TMJ department of Tehran University dental school in 2010-11 .
Materials and Methods: In a descriptive cross-sectional trial, 85 TMD patients treated at the TMJ department of Tehran University dental school were examined at least 3 months after the treatments. The patients demographic data ,TMD signs and symptoms and the improvements occurred in TMD disorder were determined (complete, partial and no improvement). The patients satisfaction regarding the treatment results were investigated and data were analyzed regarding the presence of different TMD signs and symptoms before and after the treatment using Mann-Whitney U test .
Results: TMJ pain (35 cases, 42.2%), click (33 cases, 39.8%) and muscle tenderness (26 cases, 31.3%) were the most prevalent obtained signs and symptoms. The mean age of the patients were 32.3 years old while females were the predominant group (72 cases vs.11 one). 44 individuals (53.0%) were treated by splint, 11 ones (13.3%) with anterior repositioning splint and 17 individuals (92.5%) were managed by physiotherapy plus splint. 65 patients (87.3%) were satisfied with the results and 16 ones (19.3%) were not. After the treatment, patients with TMJ pain (P<0.001) and muscle tenderness (P<0.001) showed significantly lower satisfaction than that of patients with no signs. No other significant differences were noted between patients satisfaction regarding the presence of TMD signs and symptoms (P>0.05) .
Conclusion: The results showed that the treatments presented for the TMD patients at Tehran University dental school were successful and most patients received satisfactory treatment.
Farzaneh Aghahosseini, Nafiseh Sheykhbahaei,
Volume 30, Issue 3 (10-2017)
Abstract
Background and Aims: Headache is among the most common complaints in patients suffering from temporomandibular joint disorders (TMD). Thus, it seems that evaluation of patients with headache in terms of temporomandibular joint (TMJ) disorders is necessary. In people with TMD, parafunctional activities play an important etiologic role. Considering the high prevalence of bruxism and TMDs in patients with headache, assessment the accuracy and severity of this association can play a key role in diagnosis and treatment of these two phenomena. The purpose of this study was to investigate the relationship between bruxism, TMD and headache, also assessment the efficacy of TMD conservative therapy with a special approach to self-management in treating patients with headache.
Materials and Methods: Motor searches of Cochrane, Medline and EMbase databases, PubMed, Google Scholar, Uptodate, BMJ clinical Evidence, MD consult and science direct by using of relevant key words were searched for article published between 2000 and 2015. A total of English language abstracts were reviewed, 80 full articles were obtained and among them, 30 relevant articles were reviewed in this study. Because of the high number of studies in this field, we divided the data into four group, bruxism and TMD, TMD and headache, bruxism, TMD and headache, treatment.
Conclusion: Bruxism and temporomandibular disorders are the two main contributing factors in initiation and perpetuation of headache. Treatment of these two phenomena would be effective in the treatment of headache.
Alireza Omrani, Pedram Daneshkazemi, Amir Mansour Shirani, Mohammad Amin Habibi,
Volume 34, Issue 0 (5-2021)
Abstract
Background and Aims: Temporomandibular joint disorders (TMDs) are one of the most common causes of the patient's referral to dental clinics. Considering the role of related factors in its creation, the purpose of this study was to investigate the relative frequency of factors related to temporomandibular disorders in patients aged 20 to 50 years referred to dental clinics in Isfahan in 1397.
Materials and Methods: In this descriptive and analytical study, 324 patients referred to Isfahan dental clinics in 1397 were randomly included. Factors related to TMD and demographic factors of patients were recorded with clinical examination by a trained dentist and self-declaration of patients in the data collection form. The frequency and relevance were analysed by SPSS 22 software and chi-square, fisher and logistic regression statistic tests.
Results: At least one of the TMD related factors was present in 40.7% of the subjects, which the most common factors related to TMD was posterior edentulousness (49.7%). History of jaw dislocation was more common in men (P=0.014) and the frequency of posterior edentulousness was more common in in women (P=0.003). As the age increased, the frequency of posterior edentulousness (P=0.000) and earache (P=0.009) increased. The frequency of posterior edentulousness was higher in housekeepers (P=0.000), the frequency of earache was higher in employees (P=0.005) and the history of jaw dislocation was higher in self-employed persons (P=0.047). |
Conclusion: The high prevalence of TMD and related factors, such as a history of jaw dislocation, posterior edentulousness, earache, and clenching, requires attention to be identified and treat these problems.
Seyed Ramin Nourbakhsh, Hamideh Yosefpour, Freshteh Osmani,
Volume 34, Issue 0 (5-2021)
Abstract
Background and Aims: In impacted third molar surgery, panoramic radiography is a preliminary technique for assessing the consequences associated with inferior alveolar nerve injury. However, this technique cannot provide enough information to determine the true risk in all cases. The aim of this study was to compare the accuracy of panoramic and CBCT radiographs in evaluating the relationship between the mandibular impacted third molars and the inferior alveolar nerve.
Materials and Methods: In this cross-sectional study, the relationship between mandibular third molar and inferior alveolar nerve in 15 patients referred to the oral and maxillofacial radiology department of Birjand dental school including 20 mandibular third molars were evaluated using two panoramic and CBCT radiographs. Data were analyzed using descriptive statistics and chi-square test and sensitivity analysis in SPSS22.
Results: In the evaluation of the teeth using panoramic radiography, the highest frequency was related to root darkening (65%) and root deflection (65%), and the lowest frequency was related to root narrowing (20%) and canal deviation (5%). The highest sensitivity of panoramic criteria was related to the root darkening with 100% sensitivity and the lowest sensitivity was related to the canal deviation with 17% sensitivity. On the other hand, the highest specificity of panoramic criteria between the mandibular third molars with the inferior alveolar nervewas was related to the two criteria of bifid apex and canal deviation with 100% specificity. The lowest specificity was related to the root deflection with 21% of specificity.
Conclusion: According to the results of this study, the probability of observing relationship between the mandibular third molars with the inferior alveolar nerve in CBCT radiography was very high.
Mehrdad Shahraki, Amir Hossein Khazaei, Arash Azadi, Sadra Amirpour Haradasht,
Volume 36, Issue 0 (5-2023)
Abstract
Background and Aims: Mandibular third molar is the most common impacted tooth and craniofacial morphology and facial parameters can be appropriate predictors of impaction of this tooth. The aim of this study was to evaluate the relationship between Gonial angle, mandibular plane inclination, and ramus height with the impaction of mandibular third molar.
Materials and Methods: This retrospective descriptive-analytical study was performed by analysis of lateral cephalometric radiographic images of 172 patients in city of Zahedan in 2020. The status of eruption of mandibular third molars was determined by clinical examination and assistance of panoramic radiographic images and samples were categorized into four groups: fully erupted (1), partially impacted (2), impacted (3), partially developed (4). Then, the Gonial angle, mandibular plane, and ramus height were measured on lateral cephalometric images of each group and collected data were analyzed by Chi-square test and analysis of variance (ANOVA).
Results: Among the patients, 68.02% were female and 31.97% were male. The difference between the mean values of Gonial angle of four groups was not statistically significant (P>0.05). In the fourth group, the mean value of mandibular plane inclination was significantly higher (29.74) and the mean value of the ramus height was significantly less (49.21 mm) than other groups.
Conclusion: According to the preformed analysis and obtained results, Gonial angle, mandibular plane, and ramus height were not accurate predictors for the impaction of mandibular third molar and further studies should be undertaken in this filed.
