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Background and Aims: The surgical removal of mandibular third molar is frequently accompanied by significant postsurgical complications, and different protocols have been described to decrease such complications. The aim of this study was to compare the postoperative complications of mandibular impacted third molar removal with two conventional rotary and piezoelectric methods. Materials and Methods: In this study 27 patients with bilateral mandibular impacted third molars were selected. The patients’ teeth were extracted by the piezoelectric method on a random side and the opposite tooth was extracted by conventional rotary technique. On operation and post operation days, edema, pain, and mouth opening were assessed. The duration of each operation was also measured. Data were analyzed by Mann-Whitney test and independent t-test. Results: The mean duration of operation in the rotary group was less than that of the piezoelectric group, which was statistically significant (P=0.001). Pain was significantly higher in the rotary group on days 0 to 5 (P0.05). Edema was significantly higher in the rotary group on the first, third, and fifth days after surgery (P

Due to the increased prevalence of third molar impaction and the complications and existence of disagreements regarding the predicting factors for the impaction of this tooth, the aim of this study was to evaluate the relationship between the position of the mandibular third molar with different vertical skeletal dimensions on the panoramic images.Materials & Methods:This cross sectional study was carried out on lateral cephalogram and orthopantomogram records of 130 orthodontic patients visiting to Isfahan (Khorasgan) University Dental School. Age range of the sample was 20-35 years. Various facial forms were determined with mandibular plane angle (SN-GoGn), jarabak index and Y-axis; S-GN–Frankfort plane. Beta angle; which is the angle between intersecting long axis of mandibular second molar and mandibular third molar was measured to determine the angle of eruption of mandibular third molar. Eruption pattern was classified as per Pell & Gregory and winter’s system. The data were analyzed by Chi-square test (p value < 0.05).Results:There was a significant difference in the frequency distribution of growth pattern on the left side of the jaw (p value = 0.048). There was no significant difference in the frequency distribution of the eruption pattern in the right side of the jaw (p value = 0.11).There was no significant difference in the frequency distribution of eruption surface in the right face between different facial forms (p value = 0.49) But on the left side of the jaw there was a significant difference between the three facial forms (p value = 0.049). Frequency distribution of mandibular third molar impaction was significantly different between the three facial forms (p value = 0.03). There was no significant difference between the three facial forms in terms of frequency of eruption angle in the right side of the jaw (p value = 0.25) and also in the left side of the jaw (p value = 0.15).Conclusion:The incidence of impaction was significantly more in patients with long face than in other two groups. The prevalence of surface and pattern of third molar eruption in only one side of jaw was significantly different between the three facial forms. There was no significant difference between the frequency of angle of eruption and facial skeletal types in both jaws

Introduction: Most third molars eventually need to be extracted, and this tooth has the most varied and unpredictable root position of all teeth. Therefore, considering the importance of accurate diagnosis of the roots of molar teeth before surgery to reduce its surgical complications, the aim of this study was to evaluate the ability of panoramic radiography to diagnose the situation of roots of third molars. the relationship of the roots to each other and the angle of the crown to the root in panoramic and clinical radiographs, respectively, using Romexis viewer and digimizer software were investigated. Methods: In this cross-sectional-analytical study, 104 third molars of 93 patients referred for wisdom tooth extraction were examined clinically for the number of roots, the relationship of roots to each other and the angle of the crown to the root in panoramic radiography using Romexis Viewer software and clinically after providing photograph and measuring the angle using digimizer software. Results: In evaluating the roots of third molars, the accuracy of panoramic radiographic interpretation regarding the number of roots was 63.27% and in the presence or absence of root, adhesion was 55.89%. In addition, Pearson correlation analysis showed that there was a significant relationship between the reported angle in radiographic interpretation and the actual angle (r = 0.318 and P value = 0.001). Conclusion: Therefore, panoramic radiography is a valuable guide for third molar surgery. It is only necessary to consider its high error rate in terms of morphological details such as the number of roots and their relationship to each other.

Background and Aims: The surgical removal of mandibular third molar is frequently accompanied by significant postsurgical complications, and different protocols have been described to decrease such complications. The aim of this study was to compare the postoperative complications of mandibular impacted third molar removal with two conventional rotary and piezoelectric methods. Materials and Methods: In this study 27 patients with bilateral mandibular impacted third molars were selected. The patients' teeth were extracted by the piezoelectric method on a random side and the opposite tooth was extracted by conventional rotary technique. On operation and post operation days, edema, pain, and mouth opening were assessed. The duration of each operation was also measured. Data were analyzed by Mann-Whitney test and independent t-test. Results: The mean duration of operation in the rotary group was less than that of the piezoelectric group, which was statistically significant (P=0.001). Pain was significantly higher in the rotary group on days 0 to 5 (P<0.05). Whereas, difference in pain on day 6 was not statistically significant (P=0.067). There was no significant difference between the two groups in each day after surgery regarding mouth opening (P>0.05). Edema was significantly higher in the rotary group on the first, third, and fifth days after surgery (P<0.05). Also, edema was higher in the rotary group on the seventh day after surgery, but not statistically significant (P=0.076). Conclusion: According to the results of the present study, it can be concluded that pain and swelling in patients after impacted tooth surgery using time consuming piezoelectric technique can be reduced. [ABSTRACT FROM AUTHOR]

Impacted third molar reduces the bone level in the distal aspect of second molar, and sometimes it can lead to external root resorption of the adjacent second molar. The aim of this study was to evaluate the prevalence and quality of this resorption using cone-beam computed tomography scanning.Materials & Methods:In this descriptive study, CBCT images selected from 60 patients (including 107 maxillary & mandibular impacted third molars) were obtained from patients referring tomaxillofacial radiology department of dental faculty of Islamic Azad University of Isfahan (Khorasgan) in 2016. Under observation of oral radiologist, the images were examined (two times with one-week interval) in axial, coronal, and sagittal sections and recorded to diagnose external root resorption in CBCT. The data were analyzed via descriptive statistics including contingency tables and relative abundance.Results:The prevalence of external root resorption of second molar, adjacent to the third molar were43.25%. The most common type of third molar impaction were mesioangular third molars (41.1%) and in the next level were the vertical (28.1%), and distoangular (18.7) and then horizontal (12.1). The most common location of resorption in mandibular second molar teeth was in 1/3 of cervical (62.5%), and then 1/3 of apical (20.8%) and 1/3 of the middle (12.5%). Also one of teeth resorptions (4.2%) was between the 1/3 of apical and 1/3 of the middle. The most common site of resorption in maxillary second molar teeth was at 1/3 of the apical (68.45%), and then at the 1/3 of the middle (17.35%) and 1/3 of cervical (8.7%). With regards to the severity of resorption; 78.96% of resorptions were mild, 12.03% severe, and 9.03 were moderate.Conclusion:The prevalence of this type of resorption is almost high and the most common position of impacted third molars that resulted in this type of resorption are mesioangular and horizontal. Most common site of resorption in the maxilla was 1.3 of the apical and in the mandible was 1.3 of the cervical, which were often mild in resorption.

Introduction: Impacted third molar reduces the bone level in the distal aspect of second molar, and sometimes it can lead to external root resorption of the adjacent second molar. The aim of this study was to evaluate the prevalence and quality of this resorption using cone-beam computed tomography scanning. Materials & Methods: In this descriptive study, CBCT images selected from 60 patients (including 107 maxillary & mandibular impacted third molars) were obtained from patients referring to maxillofacial radiology department of dental faculty of Islamic Azad University of Isfahan (Khorasgan) in 2016. Under observation of oral radiologist, the images were examined (two times with one-week interval) in axial, coronal, and sagittal sections and recorded to diagnose external root resorption in CBCT. The data were analyzed via descriptive statistics including contingency tables and relative abundance. Results: The prevalence of external root resorption of second molar, adjacent to the third molar were 43.25%. The most common type of third molar impaction were mesioangular third molars (41.1%) and in the next level were the vertical (28.1%), and distoangular (18.7) and then horizontal (12.1). The most common location of resorption in mandibular second molar teeth was in 1/3 of cervical (62.5%), and then 1/3 oo oooooo (20.8%) ooo 1/3 oo ooo oooooo (12.5%). oooo ooo oo ooooo ooooooooooo (4.2%) was between the 1/3 of apical and 1/3 of the middle. The most common site of resorption in maxillary second molar teeth was at 1/3 of the apical (68.45%), and then at the 1/3 of the middle (17.35%) and 1/3 of cervical (8.7%). With regards to the severity of resorption; 78.96% of resorptions were mild, 12.03% severe, and 9.03 were moderate. Conclusion: The prevalence of this type of resorption is almost high and the most common position of impacted third molars that resulted in this type of resorption are mesioangular and horizontal. Most common site of resorption in the maxilla was 1.3 of the apical and in the mandible was 1.3 of the cervical, which were often mild in resorption. [ABSTRACT FROM AUTHOR]

Introduction: Third molar teeth are the most common teeth with agenesis. The absence of this tooth also increases the probability of anomalies in other teeth by several times. Since panoramic radiography is used to diagnose and plan treatment in orthodontic patients, along with routine clinical examination, this study aimed to determine the prevalence of third molar agenesis and incidence of other associated anomalies in comparison to that reported for the non-agenesis group using panoramic radiographs. Materials and Methods: In this descriptive-analytical study, the pretreatment records of 562 patients were randomly collected. Out of these subjects, 538 patients were selected based on inclusion and exclusion criteria. The panoramic radiographic images of patients who did not have at least one third molar were assessed with regard to the presence of other dental anomalies, such as dental agenesis, hypodontia, hyperdontia, impacted canine, peg-shaped lateral incisors, ectopic eruption, microdontia, dilaceration, transposition, and transmigration. The prevalence of these anomalies was compared to that of a randomized control group selected from patients with the presence of each four third molars. Results: Out of 538 studied panoramic radiographs, overall, 13.7%, 13.5%, 13.4%, 5.9%, 2.7%, and 1.4% of them had at least one third molar agenesis, canine impaction, peg-shaped lateral incisors, missing teeth, transposition, and hyperdontia, respectively. The frequency rates of impaction and missing teeth were higher in the agenesis group (30% and 40.5%) than those reported for the control group (16% and 2.7%) (p < /em>>0.001), respectively. The presence or absence of other dental anomalies was not statistically significant between the two groups and two genders. In addition, the present study demonstrated that the probability of the presence of at least one type of other dental anomalies was higher in individuals with third molar agenesis in comparison to that reported for the control group (p < /em>>0.001). Conclusion: Among different types of dental anomalies in the studied population, the probability of impaction and missing teeth was higher in the third molar agenesis group than that of the control group. Furthermore, the prevalence of third molar agenesis was not different between the two genders.

Introduction: Third molar removal surgery is one of the most common oral and maxillofacial operations that sometimes can be complicated and time-consuming. As a result, monitoring the vital signs of a patient during this surgery seems to be crucial. Therefore, the aim of this study was to evaluate heart rate and blood oxygen saturation variations during mandibular third molar surgery. Materials and Methods: This cross-sectional descriptive study was carried out on 50 patients who referred to the Surgery Department of the Dental School of Shiraz University of Medical Sciences, Iran for the surgical removal of the third molar. In this study, the heart rate and oxygen saturation of the participants were measured during eight phases, including when the patients were in the waiting room, sitting on dental chair, regional anesthetic medication was injected, surgeon started incising the gum, during bone removal, third molar extraction, suturing, and at the end of surgery. The data were analyzed by the repeated measures analysis of variance and independent samples t-test PResults:Our findings demonstrated that28 (56%) and 22 (46%) of the patients were male and female, respectively. The mean age of participants in this study was 30.12 years. The mean heart rate and oxygen saturation of the subjects during all the mentioned phases were found as 80.52 beats/min and 97.22%, respectively. A significant relationship was observed between the heart rate of the patients (PConclusion: According to the results of this study, the highest heart rate of the patients under third molar removal surgery was recorded during the local anesthetic injection. Furthermore, oxygen saturation remained in the normal range during this operation.

Background and Objective: Extraction of impacted lower third molars is one of the most frequent surgeries of the oral cavity. This operation might be accompanied by inevitable complications, such as pain, swelling, and trismus after surgery. Therefore, the aim of this study was to evaluate the impact of low-intensity/power laser therapy on swelling and trismus after impacted mandibular third molar surgery. Materials and Methods: This randomized double-blind clinical trial was performed on 40 patients who required similar unilateral impacted third molars. These patients were randomly divided into two groups of 20, including the control group with no laser application and the test group receiving laser irradiation. In the intervention group, 1 cm2 of the tissue was irradiated immediately post-operation by 12 j/cm2 energy using a 980-nm laser setting with continuous wave mode at the output power of 200 MW for 60 s. Radiations were carried out at three regions, including two intraoral sites on the buccal and lingual sides of the operated area and an extraoral area on the joining point of the masseter muscle to the mandible. Inflammation and trismus were assessed by measuring the size of the face and maximum mouth opening on the second and seventh days after surgery. Results: Our findings demonstrated that in the laser group, on the second day post-operation the maximum mouth opening (trismus) was 28±6 and facial swelling was 217.8±12.8. The two groups were not significantly different on this day regarding the two evaluated variables (P>0.05). On the seventh day, trismus and facial swelling were reported as 39.85±6.97 and 209.2±13.45, respectively. Moreover, improvements were observed in the irradiated group at this time point. However, no statistically significant difference was found between the test and control group concerning these factors (P>0.05). Conclusion: According to the results of this study, laser application with the parameters set in this study had no significant positive effects on reducing the post-operation complications.

BACKGROUND AND OBJECTIVE: Injury to the inferior alveolar nerve during extraction of mandibular third molars is one of the serious complications after surgery. Therefore, the precise localization of IAN in relation to the third molar is one of the critical issues before extraction of this tooth. The aim of this study was to evaluate the position of mandibular canal in the mandible and its relation to the roots of the third molar using cone-beam computed tomography (CBCT) in a selected Iranian population. METHODS: In this cross-sectional study, the CBCT images of 168 patients (214 mandibular third molars) were evaluated. The position of the mandibular canal in the mandible (lingual, central, buccal) and the position of the mandibular canal with respect to the root apex (lingually, centrally and buccally), were recorded. FINDINGS: Mandibular canals were located lingually in 68.5% of cases, centrally in 27.3% of cases, and buccally in 4.2% of cases(p

Introduction: The aim of this study is to determine and compare the eruption space of unerupted and erupted third molars by the means of digital panoramic radiography in patients referring to Yazd dental college during 2011-2013. Methods: In this cross-sectional descriptive study, 150 archived digital panoramic radiographies in radiology department were evaluated with Romexis software under the standard circumstances. The radiographic pictures belonged to 73 men and 77 women with the average age of 21.18±1.67 years. In patients with erupted third molars as well as unerupted third molars (mesio-angular and vertical), several parameters were examined including: angle of the tooth axis of second and third molar, Gonial angle, the width of third molar, retro-molar space and its ratio to the width of third molar, the development stage of third molar root as well as the distance between the center of ramus and the most distal point of second molar. The data related to age, sex and the eruption situation of lower third molar- unerupted or erupted- were extracted from the patient’s log. The data were analyzed by SPSS (ver.17) via applying descriptive tests and T-test. Results: A statistically significant difference was observed between the two groups in regard with the average angle between second and third molar, the mean space of retro-molar and its ratio to the width of third molar as well as the mean distance between centers of ramus and second molar (P=0.0001). Moreover, no significant difference was observed in Gonial angle mean (P=0.213) and the width of third molar (P.value=0.348). Conclusion: Increasing the angle between second and third molar as well as inadequate space of retro-molar can lead to impaction of lower third molar, but the width of third molar and the Gonial angle size did not reveal any significant role in determination of impaction or eruption of third molar.

Background and Objective: The impacted tooth is trapped tooth by an obstruction on the budding path. The existence of impacted mandibular third molar leads to increase of in the caries in the distal neck of second molar due to the contact of third molar. Subjects and Methods: This study was analytical crosssectional study conducted from May 2014 to March 2015 among 50 patients with mandibular third molar impaction. Panoramic X-rays and Bitewing radiograph was taken to determine the impaction types and the presence or absence of the second molar caries. Chi-square test was used to investigate the relationship between the mandibular third molar impaction and mandibular second molar distal surface caries. Data were analysis by SPSS software version 18. P<0.05 was considered as significant level. Results: The most common type of dental impaction was the mesioangular (34%). Distoangular and horizontal was (24%) while the vertical impaction was (18%). The degree of impaction in class II (80%) and for class III (20%) were recorded. According to the classification of Pell and Gregory, classes B was classified as the most prevalent impaction, and class A was the lowest. The prevalence of caries was reported in 52% cases. 38.48% cases of caries belonged to mesioangular impaction form which was significantly higher than other types (P<0.05). Conclusion: Our study showed that the angle of impaction (mesioangular and horizontal) and the class II had significant correlation with caries.Background and Objective: The impacted tooth is trapped tooth by an obstruction on the budding path. The existence of impacted mandibular third molar leads to increase of in the caries in the distal neck of second molar due to the contact of third molar. Subjects and Methods: This study was analytical crosssectional study conducted from May 2014 to March 2015 among 50 patients with mandibular third molar impaction. Panoramic X-rays and Bitewing radiograph was taken to determine the impaction types and the presence or absence of the second molar caries. Chi-square test was used to investigate the relationship between the mandibular third molar impaction and mandibular second molar distal surface caries. Data were analysis by SPSS software version 18. P<0.05 was considered as significant level. Results: The most common type of dental impaction was the mesioangular (34%). Distoangular and horizontal was (24%) while the vertical impaction was (18%). The degree of impaction in class II (80%) and for class III (20%) were recorded. According to the classification of Pell and Gregory, classes B was classified as the most prevalent impaction, and class A was the lowest. The prevalence of caries was reported in 52% cases. 38.48% cases of caries belonged to mesioangular impaction form which was significantly higher than other types (P<0.05). Conclusion: Our study showed that the angle of impaction (mesioangular and horizontal) and the class II had significant correlation with caries. [ABSTRACT FROM AUTHOR]

Introduction: Mandibular third molar surgery is one of the most common oral surgeries in which pain and swelling is a common finding. The purpose of this study is to compare pain and swelling after Surgical Extraction of Mandibular Third Molar in dexamethasone Injection to Medial pterygoid muscle, gluteal muscle & without Corticosteroid Method. Materials & Methods: This study was a clinical trialon77patients with impacted mandibular third molar attending the School’s oral and maxillofacial department. Patients were randomlydivided into 3 groups: The first group did not receive any corticosteroid, The second group receive 8 mg dexamethasone in gluteal muscle after surgery and in third group 8 mg dexamethasone was injected to medial ptrygoidpreoperativly. The pain and swelling was measured48 hoursand7 daysaftersurgery. Datas were first analyzed by the Kruskal–Wallis and ANOVA tests, followed by the Mann–Whitney test (p value < 0.167) Results: Both groups received dexamethasone in gluteal muscle or inmedialptrygoidhad significantlylesspain (p value < 0.001) and swelling (p value < 0.006) at the48- hourfollow-upcomparing with thegroupwithoutcorticosteroids. While there was not any significant difference in 1-week follow up. Conclusion: Injection of dexamethasone in medial pterygoid muscle is effective in reducing post operative pain and swelling and its effects are comparable with systemic injection in the gluteal muscle. [ABSTRACT FROM AUTHOR]

Background and Aims: Impacted third molar reduces the bone level in the distal aspect of second molar, and sometimes it can lead to root resorption of the adjacent tooth. The purpose of this study was to determine this resorption using panoramic and periapical radiographs. Materials and Methods: In this cross-sectional descriptive study 54 patient (28 men, 26 women) above 15 years old with the average of 22 years in Oral and Maxillofacial Department of Tehran University were studied. A periapical radiography from the third molar and a panoramic radiograph were taken from each patient (Because of their routine use and evaluation of accuracy of panoramic compared with periapical), and the magnitude of the root resorption for the second molar was determined by 2 observers and written in a questionnaire. Data were analyzed using Fisher test. Results: The prevalence of the root resorption of the second molar adjacent to the impacted third molar in the panoramic and the periapical radiographies, with respect to the limitation of the sample size were 46.3% and 31.5%, respectively, with 95% confidence(P>0.05). Most of these resorptions were in the cervical third of the second molar roots and in cases in which the third molars were mesially oriented or horizontal. There was also no significant difference between panoramic and periapical radiographs. Conclusion: Due to the increased risk of the resorption of the second molar adjacent to the third molar, extraction of the impacted third molars, especiall y mesially oriented or horizontal ones are recommended.

Background and Objective: Impacted molars teeth, especially third molar, are important in most branches of medical sciences. The angular position of molar teeth is in side effects and therapeutic regiment. This study was conducted to determine the angle of the impacted mandibular third molars. Materials and Methods: This descriptive study was carried out on 429 patients (269 men and 160 women) selected for surgery on impacted mandibular third molar in the oral and maxillofacial surgery clinic in Gorgan, Iran during 2010-11. Pre-operative diagnosis was done by physical examination and OPG radiography. Demographic characterstics including age, gender, ethnicity, impaction angle were recorded for each subject. Data were analyzed using SPSS-16, independent t-test and chi-square test. Results: Totally, 480 impacted third molars were studied. Mean age of patients was 26.06±6.21 years. Impaction of the third molar was more prevalent among men (62.7%) than women (38.30%). Impacted mandibular third molar of 189 people (44.1%) were in left side in 200 people (46.6%) were in right side and in 40 people (9.3%) were bilateral. According to impaction angle, mesioangular (41.7%) and distoangular (3.5%) types had the highest and the lowest frequency, respectively. In bilateral cases, the mesioangular-mesioangular type (48.8%) was the most prevalent. The mesioangular type was the most prevalent in all ethnic groups. The most prevalent angular position of the impacted third molar was the mesioangular type in both sexes. Conclusion: This study showed that the most prevalent angular position of impacted mandibular third molar is the mesioangular type.

Introduction: It is possible to estimate an individual’s age when the birthday is indefinite by dental eruption stages. At 14‒21 age range only third molars are being developed. Therefore, the aim of this study was to evaluate the relationship between the eruption stages of third molars and chronological age in a group of 14‒21 year-old subjects.Materials and Methods: In this descriptive–analytical study, carried out during spring and summer 2012 in two clinics of the university, 180 panoramic radiographs of 34 males and 146 females were assessed; the subjects were in the 14‒21 age range. Eruption stages of third molars were divided into 4 stages: 1. no emergence; 2. alveolar eruption; 3. gingival eruption; and 4. complete eruption. Then the relationship between these classifications and chronological age was evaluated separately in relation to sex. Then the relationship was used to predict each subject’s age. Pearson’s correlation test and regression analysis were used for data analysis with SPSS 11.5 ( α= 0.05).Results: Spearman’s correlation coefficients of teeth 18, 28, 38 and 48 were 0.621, 0.659, 0.659 and 0.633 in males and 0.658, 0.648, 0.636 and 0.614 in females, respectively (p value < 0.001 in all the cases). The mean ages for alveolar, gingival and complete eruptions were 15.46, 15.92 and 19.12 years in males and 16.03, 18.02 and 19.06 years in females, respectively.Conclusion: There is a significant relationship between eruption stages of third molars and chronological age. Evaluation of wisdom teeth separately in relation to sex can be used for estimation of age. Key words: Chronological age, Third molar, Tooth eruption

مقدمه: جابجا شدن دندان مولر سوم به فضاهای آناتومیک یکی ازعوارض نادرحین خارج کردن دندان می‏باشد. در این مقاله یک مورد جابجا شد ن تصادفی دندان مولرسوم فک پائین به فضای تحت فکی گزارش می‏شود. گزارش مورد: بیمار آقای 33 ساله جهت خارج کردن دندان عقل به دندانپزشک مراجعه کرده بود. حین استفاده از الواتور،دندان ناپدید شده و وارد کف دهان شده بود. نتیجه گیری: برای جراحی دندان عقل بایستی قبل ازجراحی ارزیابی دقیقی از وضعیت دندان داشت و از وسایل و تکنیک مناسب استفاده کرد.

AbstractIntroduction: The influence of third molar eruption on vertical facial growth has been evaluated less frequently by researchers. The aim of this study was cephalometric evaluation of the effect of third molar eruption on skeletal facial height.Materials and Methods: The subjects in this cross-sectional/analytical study consisted of thirty patients with four completely erupted third molars with proper occlusal relationships (group A) and thirty patients without third molars (group B). All the subjects were 19‒24 years of age and had Class I occlusal relationship. None of the subjects had received any orthodontic and surgical treatment. Cephalograms of subjects were traced carefully. The mean of parameters measured in both groups were compared by independent t-test (α = 0.05).Results: Means of Frankfort mandibular angle (FMA) in groups A and B were 32.26 ± 5.82 and 27.20 ± 2.53 degrees, respectively, with significant differences between the two groups (p value = 0.001). Means of gonial angles in groups A and B were 123.86 ± 1.26 and 124.5 ± 4.88 degrees, respectively, with no significant difference between the two groups (p value = 0.491). Regarding ANB and SNA angles, no significant differences were observed between the two groups (p value = 0.335) and (p value = 0.127), respectively. However, there were significant differences between the two groups in relation to SNB angle (p value = 0.05). There were significant differences in relation to posterior facial height: anterior facial height ratios and sella‒ nasion distances between the two groups (p value = 0.001). However, there were no significant differences between the two groups in relation to nasion‒ menton distances (p value = 0.733).Conclusion: Craniofacial development in patients with completely erupted third molars is different from those with no third molars. Patients with third molars have larger FMA angles and greater posterior facial height (PFH). Eruption of third molars does not influence the gonial angle.Key words: Cephalometry, Third molar, Tooth eruption.

Introduction: Radiographic evaluation of mineralization stages of third molars is a valuable and important criterion for age estimation in legal medicine. The pattern of dental development is hereditary and differs from race to race. Therefore, the aim of this study was radiographic evaluation of developmental stages of third molars based on chronological age in Gilani children and young people.Materials and Methods: In this descriptive, analytical cross-sectional study, 400 panoramic radiographs from Gilani patients with an age range of 6-22 years were evaluated and developmental stages of third molars were recorded by Demirjian method. The mean age of the subjects in every developmental stage was determined. The correlation between age and developmental stage was analyzed by Spearman's correlation coefficient. The differences between right and left sides, and upper and lower jaws were analyzed by Wilcoxon test and sex differences were analyzed by Independent t-test (p value < 0.05). Regression equations was obtained for age estimation (α = 0.05).Results: The youngest age for observation of third molar bud was 6 and the oldest age was 11 in both jaws. There was a strong correlation between age and third molar developmental stage. There were no significant differences between right and left sides, but there were significant differences between upper and lower jaws. Comparison between males and females revealed significant differences in only the C stage of left mandibular third molars and A and E stages of left maxillary third molars.Conclusion: Within limitations of the present study, radiographic evaluation of third molar development in Gilani children and adolescents might provide a reference for age estimation. Key words: Age estimation, Panoramic radiography, Third molar

"nBackground and Aims: One of the common human evolutionary anomalies is dental Missing. Evolution of dental system is toward deduction of teeth number. The Missing of third molar is interesting subject for dentists and genetic researches because of its variety in different races. Consideration of bilateral effect of third molar Missing with jaw relation is an important subject. The aim of this study was to evaluate the third molar missing in Cl I and Cl II skeletal (without rotation) and comparison of them together. "nMaterials and Methods: The patients of the orthodontic department of school of Dentistry (Tehran University of Medical Sciences) were analyzed. About 121 patients had Cl I and 60 patients had ClI jaw relation. This relation identified based on cephalometric lateral radiographic ANB corner angle. Patient who had rotation in maxilla or mandible based on SN-Go Gn angle were excluded. The incidence of third molars agenesis in individual dentition quadrants, upper and lower jaw and right and left side of dentition was examined from panoramic radiography. AChi-square test was used for statistical analysis of data. "nResults: Missing of one or more third molar in skeletal Cl I and Cl II was 43% and 33.3%, respectively. Missing of one or more third molar in Cl II was fewer than Cl I, but no statistically significant differences were seen between them. "nConclusion: There was not a direct relationship between jaw relation and third molar Missing.

مقدمه:دندان‏های مولر سوم شایع ترین دندان‏هایی هستند که دچار غیبت مادرزادیمی گردند. با در نظر گرفتن این مسئله که غیبت یا حضور این دندان‏ها می تواند طرح درمان‏های ارتودنسی، اطفال و پیوندهای جراحی را تحت تاثیر قرار دهد، تعیین وضعیت آنها قبل از انجام این درمان‏ها امری ضروری می باشد. هدف از این مطالعه بررسی فراوانی غیبت مادرزادی مولرهای سوم و تغییرات همراه با آن در بیماران 25-14 ساله مراجعه کننده به دانشکده دندانپزشکی مشهد بود. مواد و روش‏ها:این مطالعه از نوع مطالعات مقطعی، توصیفی- تحلیلی می باشد که در آن رادیوگرافی‏های پانورامیک بیماران 25-14 ساله مراجعه کننده به دانشکده دندانپزشکی مشهد (طی سال 1385) مورد بررسی قرار گرفتند و در ارتباط با غیبت مادرزادی مولرهای سوم و فاکتورهای وابسته به آن نظیر جنس، هیپودنشیا و سابقه خانوادگی برای هر بیمار پرسش نامه ای تکمیل شده و اطلاعات به دست آمده با استفاده از آزمون‏های Mann-Whitney و Wilcoxon مورد تجزیه و تحلیل قرار گرفتند. یافته‏ها:1- شیوع غیبت مادرزادی مولرهای سوم 2/11% بود که اختلاف آماری معنی داری میان دو جنس وجود نداشت. 2- در 60% از افرادی که دارای غیبت مولر سوم بودند، غیبت در سایر دندان‏های دائمی و در5/7% این افراد، آنومالی در سایر دندان‏های دائمی وجود داشت. 3- در 3/23% از افرادی که دارای کوچکی فک بالا بودند، دارای غیبت مادرزادی مولر سوم مشاهده شد. 4- تفاوت آماری معنی داری میان غیبت مولر سوم در فک بالا و فک پایین و نیز سمت راست و چپ وجود نداشت. نتیجه گیری: فراوانی غیبت مادرزادی مولر سوم در جامعه ما مشابه با سایر جوامع بوده و ارتباط مستقیمی میان آژنزی مولر سوم و آژنزی و آنومالی در سایر دندان‏ها و نیز کوچکی فک بالا وجود داشت.

Introduction: The impaction of third molars is very common. Due to the possible damages due to impaction and the effect of its angulation on treatment, it is important to study this pattern. The aim of this study was to determine the frequency of impacted mandibular third molars separately for each angulation on panoramic radiographs of patients referred to the Department of Maxillofacial Radiology, Esfahan Faculty of Dentistry. Materials & Methods: This retrospective descriptive study was performed on 1000 panoramic radiographs available in the Department of Maxillofacial Radiology, Esfahan Faculty of Dentistry in 2013‒2014. The patients' data, including gender and angulation of the impacted teeth, were recorded. Data were analyzed with chisquared test, using SPSS 17 (α = 0.05). Results: The majority of impacted third molars were found in female patients with 228 cases (58.91%), followed by male patients with 159 (41.08%) of 387 unilateral and bilateral cases of impacted third molars. The most frequent angulation was vertical with 247 cases (40.8%) and the least frequent angulation was buccolingual with 22 cases (3.62%). There were 218 bilateral impactions (59.09%). Chi-squared test showed significant relationships between the frequency of impaction of third molars and dentitions with no extracted teeth and those with one or more extractions (p value < 0.001). In addition, there were no significant differences in the complete dentitions and those with extracted teeth between males and females (p value = 0.953). Conclusion: This study showed that the most common angulation of impaction of mandibular third molars was vertical and the buccolingual angulation exhibited lowest rate of impaction. Bilateral impaction was the most common mode and wisdom tooth impaction was more frequent in female patients. [ABSTRACT FROM AUTHOR]

Background & Objectives: Most people fail to have necessary dental care because they're anxious to go to the dentist due to lack of the knowledge about dental procedures .The aim of this study was to evaluate the effect of verbal explanation in reduction of dental stress before third molar operation. Materials and Methods: This study designed as controlled clinical trial. Totally 60 patients selected from those referred to the oral and maxillofacial surgery department، dental faculty of Tabriz. After verbal expranation، the questionnaire consisted of demographic characteristics (age، education، life status، number of dental visits before surgery) and mean of pain according to visual analogue scale (VAS) was recorded. Data were analyzed by descriptive statistics (mean ± SD)، T-test and chi-square test by using SPSS.20 (P < 0.05). Results: Based on VAS scale، the mean of stress in control group was higher than test group (5.91vs. 4.22 before surgery) and (5.61 vs. 3.115 after surgery) (P<0.05). The difference between age، gender، education، life status and hospitalization was not statically significant between the control and test groups. [ABSTRACT FROM AUTHOR]

AbstractDry socket is undoubtedly on tne most distressing post operative sequel of teeth extraction. It occurs in spite of the most careful aseptic procedures and regardless of the ability and skills of the surgeon. The purpose of this study was to determin the relative frequency of dry socket after mandibular wisdom teeth extraction and defining the risk factors corresponding to this complication. This descriptive-analytic study was performed on 386 patients who were candidate for wisdom teeth extraction. A medical history was taken. Some of these patients were found to have a history of smoking and were taking birth control pill. Operation time and trauma during extraction, and the oral hygiene status of patients were recorded. Three days after extraction the patients were recalled and examined for dry socket.The findings revealed the relative frequency of the dry socket was 7.5% (29 patient). Its occurrence was more in females than males, and maximum incidence was in the age between 20-40. The incidence were related to trauma and duration of extraction, history of smoking and oral contraceptive pills and pericoronitis, and had no specific relation with periapical lesions and oral hygiene.In this study, Similar to other studies, specific relation was found between dry socket and other factors like, smoking and age. But something which was obvious was the close relation of dry socket with the intensity of trauma during extraction.Key words. Dry socket, Tooth extraction, Third molar.

Introduction: Pain and complications are common after surgical removal of impacted third molars. The present study was undertaken to evaluate the effect of an oleous suspension of calcium hydroxide (OSTEORA) on pain severity and complications after surgical removal of impacted third molars. Materials and methods: This clinical trial evaluated 30 patients with an age range of 17‒40, referring to a maxillofacial surgery department and two private clinics in Tehran in 2011‒2012 for surgical removal of bilaterally impacted third molars with the same difficulty index. OSTEORA was used on one side and no material was used on the contralateral side as the control. The effect of OSTEORA was evaluated on pain, healing, hemorrhage, dry socket and infection at different postoperative intervals in a double-blind manner. Data were analyzed with chi-squared and MannWhitney U tests (α=0.05). Results: Of 60 samples, 28 were from the maxilla and 32 were from the mandible. Intensity of pain in the study groups at baseline and at follow-up intervals was the same (p value = 0.4). The incidence of hemorrhage at follow-ups was the same in both groups (p value < 0.5). Maxillary healing rates on the 3rd postoperative day in the control and test groups were 3.21±2.39 and 2.42±2.17, respectively (p value < 0.03) and on the 7th postoperative day they were 2.9±2.58 and 2.14±2.28, respectively (p value < 0.03). Healing in mandible in both groups was the same at follow-ups (p value < 0.2). No dry sockets and infection were observed in any subject. Conclusions: Under the limitations of the present study, use of an oleous suspension of calcium hydroxide had no effect on the incidence of hemorrhage and pain after surgical removal of impacted third molars. However, it affected healing of the surgical site, especially in the maxilla. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Introduction: Dentists use panoramic radiographs to assess the relationship between impacted wisdom teeth and inferior alveolar canal before their surgical removal to avoid injuries to inferior alveolar nerve. The aim of this study was to evaluate inferior alveolar canal configuration and position adjacent to the impacted mandibular third molar by panoramic radiography. Materials and Methods: In this descriptive study, standard panoramic radiographs with 384 impacted lower third molars were selected. The relationship between inferior alveolar canal and the roots of impacted mandibular third molars was evaluated by two experienced experts. Data were analyzed by SPSS 11.5 using descriptive statistics. Results: Evaluation of panoramic radiographs showed superimposition of the canal on third molar roots (85.4%), periapical radiolucency (28.4%), a decrease in the density of tooth roots (19.8%), deviation of mandibular canal (11.5%), narrowing of mandibular canal (3.4%), interruption of radiopaque border of mandibular canal (2.9%), and external root resorption (2.1%). In some cases more than one abnormality were observed in tooth roots. Conclusion: In the present study, superimposition of the roots of third molars on the superior border of the inferior alveolar nerve canal and external root resorption of third molars were the most and least common anomalies on radiographs, respectively. In addition, mesial angulation, class I and type B were the most common types of impaction of mandibular third molars. [ABSTRACT FROM AUTHOR]

Background and Objective: Mandibular fractures are about 40-65 % of facial fractures which appeared to be more prevalent in facial fractures. Among the many factors that can affect the mandibular fracture, the third molar is an important factor. This study's goal was to analyze the relationship between 3rd molar growing status (impacted vs. full growth) and angle fractures in a group of patients referred to the department of maxillofacial surgery of Imam-Khomeini hospital of Ahwaz. Subjects and Methods: This is a descriptive cross-sectional study which examines the status of 3rd molar in patients with angle fractures of mandible referring to Imam-Khomeini hospital of Ahwaz in years 2011 and 2012. Panoramic radiographic view of the patients was studied to determine the 3rd molar status and its direction according to Schiller and Pell & Gregory classifications. Results: The samples studied in this research were 50 cases(40 male and 10 female) with mean age of 26.5 years. Overall, 34(68%) patients had a 3rd molar in class IA situation,8 (16%) patients had class IB. The 3rd molar in 8 patients divided into classes IC,IIC,IIIC,IIIB equally. Growing 3rd molar of Class IA in Pell & Gregory system and also being vertical in Schiller system, had the most risk of angle fracture. Conclusion: When the 3rd molar is deeper, there is a lower risk for angle fracture. [ABSTRACT FROM AUTHOR]

Introduction: Mandibular third molar impaction can sometimes be associated with pathological phenomena such as caries, pericoronitis and cystic lesions. The aim of this study was determination of some anatomic factors, including gonial, alpha and beta angles and Ganss ratio for predicting mandibular third molar impaction. Material and methods: In this cross-sectional descriptive/analytical study, 98 panoramic radiographs of patients, aged 20‒30, were divided into two groups of erupted and mesioangularly impacted third molars. Inclination of the third molar to the second molar (beta angle), third molar angle to the base of the mandible (alpha angle), the distance between the most distal point of the second molar to the anterior border of the ramus (Ganss ratio), and the angle between the posterior border of the ramus and lower border of mandible (gonial angle) were recorded. Data were analyzed by t-test using SPSS 11.5 (α=0.05). Results: Means of gonial angles in the mesioangularly impacted and erupted groups were 122.8° and 122.5°, respectively, with no significant differences (p value = 0.66). Means of beta and alpha angles and Ganss ratios in the erupted group on the right side were 42.64°, 86.11° and 1.24 and in the mesioangularly impacted group they were 21.48°, 70.85° and 0.82. Means of beta and alpha angles and Ganss ratio on the left side in the erupted group were 9.26° and 94.1° and 1.22 and in the impacted group they were 25.7° and 71.25° and 0.82 (p value < 0.001). Conclusion: Alpha and beta angles and Ganss ratios were appropriate discriminative factors for predicting impaction of mandibular third molars. The means of Ganss ratios and beta angle were higher in the impacted group and the alpha angle was greater in the erupted group. Gonial angle could not be a suitable discriminative factor for predicting the impaction of third molars. It appears by determining alpha and beta angles and Ganss ratio on panoramic radiographs at 20 years of age it is possible to predict eruption status of third molars. [ABSTRACT FROM AUTHOR]