Evaluation of the Relationship Between Zygomatic Arch Fracture Reduction and Mandibular Movements.

Objective: The aim of this study was to evaluate the relationship between surgical zygomatic arch fracture reduction and mandibular movements in different fracture types. Materials and Methods: Fractures were classified according to the Yamamoto classification. The extent of zygomatic arch reduction after surgery was evaluated by measuring three reference points on both fractured and normal side both before and after surgery. The selected reference points were: the most anterior (A1), the most posterior (B1) and the midpoint (C1) relative to midsagittal plane on the fracture side and the same points on the normal side (a1, b1, c1). Mouth opening, movements to right and left were recorded in these patients. Results: The highest extent of zygomatic arch reduction was observed at the midpoint of the arch (p = 0.041). Surgery did not significantly alter other points of the zygomatic arch. The extent of reduction of the zygomatic arch was not significantly associated with mandibular movements. However, type of fracture correlated with lateral excursion to the right and left (p = 0.002 and p = 0.031, respectively). Conclusion: This study showed that the amount of post-surgical changes in zygomatic arch reduction was not significantly related to mandibular movements. In addition, the amount of lateral excursion two weeks after surgical correction of more severe types of zygomatic arch fractures was less compared with other fracture types. Patients with more severe fractures may need to be followed for a longer period of time in order to regain the normal mandibular movement range.

Computer Assisted Bone Age Estimation Using Dimensions of Metacarpal Bones and Metacarpophalangeal Joints Based on Neural Network.

Statement of the Problem: Bone age is a more accurate assessment for biologic development than chronological age. The most common method for bone age estimation is using Pyle and Greulich Atlas. Today, computer-based techniques are becoming more favorable among investigators. However, the morphological features in Greulich and Pyle method are difficult to be converted into quantitative measures. During recent years, metacarpal bones and metacarpophalangeal joints dimensions were shown to be highly correlated with skeletal age. Purpose: In this study, we have evaluated the accuracy and reliability of a trained neural network for bone age estimation with quantitative and recently introduced related data, including chronological age, height, trunk height, weight, metacarpal bones, and metacarpophalangeal joints dimensions. Materials and Method: In this cross sectional retrospective study, aneural network, using MATLAB, was utilized to determine bone age by employing quantitative features for 304 subjects. To evaluate the accuracy of age estimation software, paired t-test, and inter-class correlation was used. Results: The difference between the mean bone ages determined by the radiologists and the mean bone ages assessed by the age estimation software was not significant (p Value= 0.119 in male subjects and p= 0.922 in female subjects). The results from the software and radiologists showed a strong correlation -ICC=0.990 in male subjects and ICC=0.986 in female subjects (p< 0.001). Conclusion: The results have shown an acceptable accuracy in bone age estimation with training neural network and using dimensions of bones and joints.

Evaluation of Superior Semicircular Canal Morphology and Its Relationship with Glenoid Fossa Roof Thickness Using Cone Beam Computed Tomography.

Purpose: This study aimed to evaluate the bone thickness of the superior semicircular canal (SSC) roof and its relationship with the roof thickness of the glenoid fossa (RGF). Methods: The cone beam computed tomography (CBCT) images of 280 patients (560 temporal regions) were surveyed. The lowest thickness of the SSC roof was measured and categorized based on the radiological patterns of the Cisneros et al. classification. The thickness of GF and the presence of dehiscence in this part were determined, as well. The relationship between the thickness of the GF roof and the bone thickness covering the SSC was also assessed. Results: The mean thickness of the SSC roof was 0.93 ± 0.48 mm, with no significant difference among different age groups and genders (p > 0.05). However, superior semicircular canal dehiscence (SSCD) was more prevalent among females over 45 years old. Similarly, the individuals with the dehiscence of the GF roof had a 12.93-fold higher chance of SSCD development. Conclusions: The results indicated that the thickness of the bone overlying the SSC was significantly related to the roof thickness of the GF. However, an increase in age resulted in no significant change in the bone thickness of the SSC roof. Gender also had no role in changing the thickness of the bone overlying the SSC. Considering the decrease in the thickness of the SSC roof among females over 45 years of age, menopause may be responsible for this occurrence as well as for the increase in the prevalence of SSCD.

Determining the existence of the foramen of Huschke in patients with temporomandibular joint disorders using cone beam computed tomography: retrospective cohort study.

BACKGROUND: Foramen of Huschke has been presented as an unusual developmental defect in anteroinferior aspect of external auditory canal. It can be associated with significant otologic complications. The purpose of this study was to determine the association between existence of foramen of Huschke and temporomandibular joint disorders in Cone Beam Computed Tomography (CBCT) images. METHODS: Of an initial sample of 465 patients, we retrospectively evaluated the CBCT images of 118 individuals with clinical signs and symptoms of temporomandibular joint disorders as case group and 256 individuals as control group. The presence, size and localization of foramen of Huschke were assessed in the axial and corrected sagittal images. The sex and age distribution were determined. Fisher's exact test, T-test and Pearson's Chi-square were applied to assess the relationship between foramen of Huschke and temporomandibular joint disorders in the case and control groups considering age and sex. RESULTS: The foramen of Huschke prevalence was slightly higher in patients with temporomandibular joint disorders (3.4%) than patients without temporomandibular joint disorders (0.8%). However, the difference was not statistically significant (P = 0.082). foramen of Huschke was found in five females and one male. There was no significant difference between case and control groups considering the age of patients with foramen of Huschke (P = 0.683). There was no significant difference between the case and control groups, considering the right and left ears in distribution of foramen of Huschke (P = 0.099) (P = 0.183). CONCLUSIONS: Higher prevalence of foramen of Huschke in patients with temporomandibular joint disorders may suggest possible mechanism for temporomandibular joint disorders development that can be affected by presence of foramen of Huschke.

A Radio-Odontometric Analysis of Sexual Dimorphism in First Molars Using Cone-Beam Computed Tomography.

OBJECTIVE: Different techniques for sex prediction are developed and used in the forensic medicine field. One of these methods is based on the teeth morphometry. The aim of the present study was to evaluate the degree of sex determination of the maxillary and mandibular first molar teeth in cone beam computed tomography images. METHOD AND MATERIALS: This study was carried out on cone beam computed tomography images of 100 men and 100 women with a mean age of 21.28 ± 2.47 years. The roof, floor and height of pulp chamber, as well as marginal enamel thickness and dentin thickness at the height of contour, tooth width, and crown length were measured. Student t test and discriminant analysis were applied to assess the differences in the measured parameters between men and women. RESULTS: According to the present study, the maxillary first molar was more dimorphic than the mandibular teeth. The accuracy of sex identification of mandibular and maxillary first molar tooth was 84% and 77%, respectively. The mesiodistal measured variables were more accurate in sexual differentiation than the buccolingual ones. For sex differentiation, the most dominant variables for maxillary and mandibular first molar teeth were crown height and dentin thickness, respectively. CONCLUSIONS: The first molar tooth showed an acceptable level of sex determination accuracy based on the odontometric measurements.

Evaluating the presence of IAN injury in patients with juxta-apical radiolucency after third molar surgery: a retrospective cohort study.

BACKGROUND: Juxta-apical radiolucency (JAR) has been presented as a radiographic sign, suggestive of the IAN injury through third molar surgery. This study aimed to evaluate the relation of JAR with IAN injury in cone-beam computed tomography (CBCT) images and to determine whether the presence of JAR is related to tooth angulation, proximity to the mandibular canal, position to the IAN, and thinning of the cortical plates. METHODS: Of an initial sample of 545 mandibular third molars, a total of 75 JAR+ and 75 JAR- teeth were evaluated by CBCT. We assessed the relationship between the presence of JAR in cone-beam computed tomography (CBCT) images and the presence of IAN injury after mandibular third molar surgeries. Moreover, we investigated whether the presence of IAN injury is related to tooth angulation, proximity to the mandibular canal, position to the IAN, and thinning of the cortical plates. Descriptive statistics, Chi-square test, and Fisher's exact test were performed for statistical analysis. RESULTS: A significant relationship was found between JAR and temporary IAN injury (P = 0.036). However, there was no case of permanent IAN injury. IAN injury showed no significant relationship with the tooth angulation, position to IAN and proximity to the mandibular canal, lingual cortical plate thinning, sex, and age. CONCLUSIONS: JAR is generally in contact with the mandibular canal, and some degree of cortical thinning can be found in most cases. In this study, JAR was significantly related to temporary IAN injury. JAR may increase the risk of nerve injury during the surgical removal of third molars.

Evaluation of Association between the Severity of Temporomandibular Disorders and Quality of Sleep in a Selected Iranian Population.

OBJECTIVES: Temporomandibular disorder (TMD), as a prevalent condition, has been reported to be related to changes in sleep quality. This study aims to assess the association between TMD severities and sleep quality in a selected Iranian population by the application of the Helkimo index and the Pittsburgh Sleep Quality Index (PSQI) questionnaire. MATERIALS AND METHODS: This study comprised 50 non-TMD subjects and 150 TMD patients, which were equally selected from each TMD severity category. The study was conducted at the School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran. The patients were first examined and categorized into four TMD severity groups according to the Helkimo index: Non-TMD, mild, moderate, and severe. Then, the patients completed the PSQI questionnaire, which was a standard version translated into Persian and adjusted for Iranian patients. RESULTS: Comparison of mean PSQI scores of the four groups revealed a significant difference (P<0.001). Pairwise comparisons showed that the severe, moderate, and mild TMD groups and the control received the highest to the lowest PSQI scores (12.26±2.35, 8.20±1.92, 6.88±1.89, and 5.28±1.32, respectively). Similarly, regression analysis indicated that by controlling the effect of demographic variables, the mean PSQI significantly increased as TMD severity increased. CONCLUSION: According to the results, all three categories of mild, moderate, and severe TMD patients showed poor quality of sleep in comparison with non-TMD controls. The higher the severity of the disease, the lower the sleep quality.

Correlation between Skeletal Age and Metacarpal Bones and Metacarpophalangeal Joints Dimensions.

STATEMENT OF THE PROBLEM: Currently, two major methods have been introduced for bone age assessment using left hand radiography. The first approach is Greulich and Pyle, which is very subjective. The second method is Tanner and Whitehouse, which is very time consuming and its morphological criteria are not quantitative, therefore it is hardly used. PURPOSE: The purpose of this study is to evaluate the relationship between skeletal age and bone size and joint space measurements among Asian children using hand radiographs and using this correlation as an aid in determining bone age. MATERIALS AND METHOD: In this analytic research, 304 hand radiographs from Asian children with normal development have been included in this study (155 female, 149 male). Two radiologists using Greulich and Pyle method assessed their bone ages. The 2nd-5th metacarpal bones length and width and 2nd-5th metacarpophalangeal joints width and length were manually measured by Adobe Photoshop and compared with subjects' skeletal age. Pearson correlation was used to determine the relationship. RESULTS: Pearson correlation between bone age and metacarpal bones length was 0.902-0.938; metacarpal bones width was 0.452-0.850; metacarpophalangeal joints width was 0.656 - 0.811, and metacarpophalangeal joints length was 0.920 - 0.947. CONCLUSION: Regarding Pearson correlation, metacarpophalangeal joints length, metacarpal bones length, metacarpophalangeal joints width, and metacarpal bones width showed significant relationship with bone age, respectively. These measurements can be used as accessory criteria for bone age assessment using left hand radiography, to reduce inter-observer reading differences.

Comparison between Glenoid Fossa Roof Thickness in TMD and non-TMD Patients, a CBCT Study.

STATEMENT OF THE PROBLEM: Various pathologic conditions can affect the thickness of the roof of glenoid fossa (RGF). The relationship between the RGF thickness and temporomandibular joint disorder (TMD) is not explicitly investigated. Considering the changes in RGF thickness, as a radiographic sign for TMD diagnosis, the phenomenon may necessitate specific treatment and may influence the treatment course and results. PURPOSE: This research was designed to examine the relationship between TMD and RGF thickness changes compared to non-TMD group. MATERIALS AND METHOD: In this cross sectional analytic research CBCT images of 70 TMD patients (140 joints) and 70 non-TMD individuals (140 joints) as control group were evaluated for thickness of RGF and presence of discontinuity in RGF. The distance between superior and inferior cortex of glenoid fossa was measured as RGF thickness. Inability to follow the course of cortex in any given image was considered as discontinuity. T-test, Chi-square and odds ratio (OR) were used for statistical analysis. In this study, p< 0.05 was considered meaningful. RESULTS: The mean thickness of RGF in our non-TMD samples was 1.12 mm. RGF thickness was significantly increased in TMD patients compared non-TMD group (p= 0.00). This value was also greater in males. On the other hand, TMD patient showed a higher incidence of discontinuity in RGF, in comparison with non-TMD patients (p= 0.006). CONCLUSION: The increased thickness of RGF can be considered as a sign of TMD, which may help in diagnosis of TMD. It seems that there is a direct relationship between TMD and discontinuity of RGF.

Osteoporosis and Jaw Abnormalities in Panoramic Radiography of Chronic Liver Failure Patients.

INTRODUCTION: Patients with chronic liver failure (CLF) are faced with many complications, because this organ is involved in various metabolic activities. Hepatic osteodystrophy is one of the major health issues encountered by this group of patients. The current study evaluated osteoporosis and bone changes in oral panoramic radiographies of cirrhotic patients. MATERIALS AND METHODS: In this study, 138 panoramic views of CLF patients, candidates for liver transplant (65 females, 73 males, aged 19-68 years) referred to Shiraz University Dental Clinic (Shiraz, Iran) for pretransplant oral examination, were evaluated. Also 138 healthy individuals (69 females, 69 males, aged 18-70 years) referred to the same clinic were examined. Abnormalities such as osteoporosis, pathologic radiolucencies, pathologic calcifications, tonsilloliths, condylar degeneration, and other findings in the alveolar bones were recorded. RESULTS: Osteoporosis was a common finding in CLF patients (p<0.001), and the probability of detecting low bone density in the panoramic view was 20.37 times higher among patients than healthy subjects. The probability of detecting pathologic jaw radiolucencies was 8.92 times higher in the case group than in the controls (p<0.001). Other bone abnormalities such as condylar degeneration and idiopathic osteosclerosis were also more prevalent in CLF patients compared to healthy subjects (p<0.001). CONCLUSION: Cirrhotic patients are prone to osteoporosis of the alveolar bones. Also, pathologic jaw radiolucencies as a result of oral infections are more prevalent in this group of patients. Routine oral panoramic views are acceptable and cost-effective radiographies for use in detecting such abnormalities in the alveolar bones as well as overall dental health. These findings also support the importance of dental health examinations prior to liver transplantation to reduce the risk of organ rejection.

How the Prevalence of Pulp Stone in a Population Predicts the Risk for Kidney Stone.

INTRODUCTION: Conflicting researches exist on relationship between pulp stones and systemic disorders. Nephrolithiasis is a common disease with severe pain and discomfort with increasing prevalence worldwide. The purpose of this study is to evaluate the correlation between pulp and kidney stones to help find a method for early detection of kidney stones. METHODS AND MATERIALS: the sample of this case-control study comprised of 154 subjects (77 patients with and 77 patients without kidney stone approved by sonographic examination). Two oral and maxillofacial radiologists evaluated their panoramic images for the presence of pulpal stones. RESULTS: A total of 42.9% of subjects showed pulp stones. Most of the teeth with pulp stone in case and control groups were molars (86.30% and 72.97%, respectively). In the group with kidney stones, pulp stones were detected in 38 patients (49.4%), while in the control group, they were detected in 28 subjects (36.4%). Although there was not a significant relationship between the presence/absence of pulp stone and kidney stone (P=0.143), there was statistically significant association between number of teeth with pulp stone in a patient and the presence of kidney stone (P<0.013). The chance of having kidney stone is 5.78 times higher in the subjects having pulp stone in three teeth or more (≥ 3 teeth). CONCLUSION: Although there is not a correlation between the presence of pulp and kidney stone, the chance of having kidney stone is 5.78 times higher in the subjects with ≥ 3 teeth having pulp stone. Thus, the number of teeth with pulp stone can serve as a predictor for possibility of having kidney stone.

A Radiographic Evaluation of Missing of Permanent First Molars in a Group of Iranian Children and Adults: A Retrospective Study.

The missing of permanent first molars influences the occlusal status and dental health. The purpose of this study was to determine the prevalence of missing first molar teeth in a selected population of Shiraz, Iran. Methods. A total of 2206 panoramic views of patients aged from 7 to 75 years old were inspected for missing of permanent first molars. Patients were categorized into five age groups: from 7 to 15, 16 to 30, 31 to 45, 46 to 60, and more than 60 years old. Data were categorized according to sex, age, and number of lost teeth using SPSS software. Results. No first molar was missing in 59.9% of the cases, 17.05% had lost one, 10.4% had lost two, 7.2% had lost three, and 5% were missing all four of their permanent first molars. The mandibular first molar was the most commonly lost tooth, and the left side in both jaws was more affected than the right side. There was a positive relation between age and missing first molar. Conclusions. A missing first molar is a common finding in southern Iran population. Due to the important role of permanent first molars in occlusion, more education and dental care is recommended to preserve these teeth.

Evaluation of Infraorbital Canal in Cone Beam Computed Tomography of Maxillary Sinus.

STATEMENT OF THE PROBLEM: Ignoring anatomic variations may lead to iatrogenic injuries by surgeons. PURPOSE: The aim of this study was to examine the relationship between the course of infraorbital canal and maxillary sinus using cone beam computed tomography scans (CBCT). MATERIALS AND METHOD: One hundred and ninety two CBCT scans were reviewed for 384 infraorbital canals. The anatomic variants of infraorbital canals were classified into three types based on the protrusion degree of the infraorbital nerve from the maxillary roof into the sinus. Measurements were made on infraorbital canal as vertical distance from the infraorbital rim to the infraorbital foramen, the maximum horizontal distance from the infraorbital canal to the canine root, the maximum diagonal length of the nerve protruded in sinus, the maximum vertical distance from the center of the nerve to the sinus roof. RESULTS: 26.5% of infraorbital canals were entirely contained within the sinus roof. 50.3% of infraorbital canals were located below the roof but remaining juxtaposed to it. In 23.2%, the nerve canal descended into the sinus. The prevalence of type3 of infraorbital canal significantly increased from 14.8% in cases without an ipsilateral Haller cell to 29.1% when a Haller cell was present. The average distance between the infraorbital foramen and the infraorbital rim were increased proportionally to the degree of protrusion of the nerve course into the maxillary sinus (ANOVA p< 0.001). CONCLUSION: The infraorbital canal protrusion into the sinus is a common variation that must be considered during surgical procedures to avoid iatrogenic injury.

Morphology and Dimensions of Nasopalatine Canal: a Radiographic Analysis Using Cone Beam Computed Tomography.

STATEMENT OF THE PROBLEM: The surgical procedure of dental implantation in anterior maxillary area may be limited by the shape and size of nasopalatine canal (NPC). CBCT imaging provides three-dimensional information for surgical planning. PURPOSE: This study is designed to evaluate the anatomy of NPC in a selected Iranian population. MATERIALS AND METHOD: In this cross sectional study, CBCT images of 301 patients were evaluated for NPC characteristics. Five linear measurements including width and length of NPC were performed on reformatted sagittal cross sections. The shapes of NPC were also classified in three groups according to Bronstein et al. classification in CBCT coronal cross sections. The effects of age and gender on measured dimension were assessed. Student's t-test, one-way ANOVA/Tukey HSD tests, chi-square and Pearson's correlation coefficient were used for statistical analysis. RESULTS: The study comprised 140 males (48.5%) and 161 females (53.5%) with mean age of 34.56±11.87. The mean length of NPC for men and women were 11.46 and 9.37 mm respectively, showing a significant statistical difference. Other dimensions of NPC and alveolar bone thickness were also greater in men with exception of buccal bone plate width in front of Stensen foramen (8.45±2.24 vs. 8.52±2.03 mm).Most of the cases showed Y-shape configuration. The diameter of oral opening of NPC (3.17±1.01 mm) was positively correlated with the patients age (r= 0.138, p= 0.01), while buccal bone over the oral opening of NPC (7.05±1.38) mm showed negative correlation with age (r= -0.199, p= 0.001). CONCLUSION: All NPC dimensions are meaningfully greater in men except for buccal bone plate thickness in front of Stensen foramen. The type of canal has no effect on dimensions of the canal.

Role of Sinonasal Anatomic Variations in the Development of Maxillary Sinusitis: A Cone Beam CT Analysis.

BACKGROUND: Several anatomical variations can lead to the inflammation of the paranasal sinuses; therefore, surgeons should be familiar with these variations and their impacts on the status of the paranasal sinuses. OBJECTIVES: The present study aimed to determine the prevalence of Haller cells and its association with patients' sex and age. Furthermore, the relationships between the presence and size of Haller cells, deviation of the uncinate process and size of the maxillary sinus ostium with the occurrence of maxillary sinusitis were investigated. MATERIALS/ PATIENTS AND METHODS: 120 coronal CBCT images were retrieved and analyzed. Statistical analysis of the data was performed by means of Mann - Whitney, χ2 and T tests. RESULTS: There were statistically significant associations between the presence and surface area of Haller cells and the occurrence of ipsilateral maxillary sinusitis. Neither the angulation of the uncinate process nor the size of the maxillary sinus ostium significantly correlates with the formation of maxillary sinusitis. CONCLUSION: Haller cells can interfere with the normal drainage of the maxillary sinus and result in sinusitis. In contrast, diameter of the sinus ostium and deviation of the uncinate process do not influence the inflammatory status of the maxillary sinus significantly.

Prevalence of Soft Tissue Calcifications in CBCT Images of Mandibular Region.

STATEMENT OF THE PROBLEM: Most of the soft tissue calcifications within the head and neck region might not be accompanied by clinical symptoms but may indicate some pathological conditions. PURPOSE: The aim of this research was to determine the prevalence of soft tissue calcifications in cone beam computed tomography (CBCT) images of mandibular region. MATERIALS AND METHOD: In this cross sectional study the CBCT images of 602 patients including 294 men and 308 women with mean age 41.38±15.18 years were evaluated regarding the presence, anatomical location; type (single or multiple) and size of soft tissue calcification in mandibular region. All CBCT images were acquired by NewTom VGi scanner. Odds ratio and chi-square tests were used for data analysis and p< 0.05 was considered to be statistically significant. RESULTS: 156 out of 602 patients had at least one soft tissue calcification in their mandibular region (25.9%. of studied population with mean age 51.7±18.03 years). Men showed significantly higher rate of soft tissue calcification than women (30.3% vs. 21.8%). Soft tissue calcification was predominantly seen at posterior region of the mandible (88%) and most of them were single (60.7%). The prevalence of soft tissue calcification increased with age. Most of the detected soft tissue calcifications were smaller than 3mm (90%). CONCLUSION: Soft tissue calcifications in mandibular area were a relatively common finding especially in posterior region and more likely to happen in men and in older age group.

Comparison between Computed Tomography and Ultrasonography in Detecting Foreign Bodies Regarding Their Composition and Depth: An In Vitro Study.

STATEMENT OF THE PROBLEM: Impaction of foreign bodies in the soft tissues is a sequela of traumatic and penetrating injuries. Such foreign bodies should be removed due to the complications they cause. Patient's history, clinical evaluation and imaging examinations aid in the proper detection and localization of the foreign bodies. PURPOSE: The aim of the present study was to compare the sensitivity of computed tomography (CT) and ultrasonography for detecting foreign bodies in in-vitro models simulating facial soft tissues. MATERIALS AND METHOD: Fifty foreign particles with five different compositions including wood, glass, metal, plastic, and stone were embedded in five calf tongues at 1, 2, 3, 4 and 5 cm depths. CT and ultrasonography were compared regarding their capability of detecting and localizing the foreign bodies. RESULTS: Wood and plastic foreign bodies were demonstrated more clearly on ultrasonography images. High density materials such as metal, stone, and glass were detected with almost the same accuracy on CT and ultrasonography examinations. Visibility of the foreign bodies deteriorated on ultrasonography images as their depth increased; however, CT appearances of the foreign particles were not influenced by their depths. CONCLUSION: Ultrasonography is an appropriate technique for detection of foreign bodies especially the ones with low density. Therefore, it seems logical to perform ultrasonography in combination with CT in cases with the suspicion of foreign body impaction.

Assessment of the changes in alveolar bone quality after fixed orthodontic therapy: A trabecular structure analysis.

Background. Tooth displacement changes the periodontium. The aim of orthodontic treatment is desired tooth movement with minimum side effects on the alveolar bone quality. The aim of the present study was to assess changes of alveolar trabeculation in children, young adults and adults and the two genders. Methods. In this cross-sectional study, 63 patients who had been treated in Department of Orthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran, were chosen with convenient sampling method. They were divided into three groups based on their age. Their digitized panoramic radiographs (PRs) were evaluated at six interdental sites from the mesial aspect of the mandibular second molars to the distal aspect of the mandibular first premolars using a visual index. The trabeculation pattern was assigned as either dense (score 3), dense-sparse (score 2) or sparse (score 1). Data were imported to SPSS. Mean of the scores before treatment (score B) and mean of them after treatment (score A) were compared for each group with paired t-test. Changes between score B and sore A of the groups were compared using one-way ANOVA and post hoc tests. Results. Mean score A was significantly higher than mean score B in children (P = 0.001). In contrast, mean score A was significantly lower than mean score B in young adults (P = 0.003). Conclusion. Orthodontists should be cautious when treating young adults and adults regarding the probable, yet possibly temporary, negative effects of orthodontic therapy on the alveolar bone quality.

Frequency of tonsilloliths in panoramic views of a selected population in southern iran.

STATEMENT OF THE PROBLEM: Tonsilloliths are relatively common clusters of dystrophic calcified material that form in the tonsillar crypts, mostly the palatine tonsils. Although they may be asymptomatic, some cause halitosis, cough, dysphagia, and foreign body sensation, as well as otalgia. Since tonsilloliths can be detected on panoramic views as radiopaque lesions, and misdiagnosis may lead to wasting time and cost, dentist should be familiar with radiographic characteristics of this type of calcification. PURPOSE: This study was conducted to determine the prevalence and the pattern of distribution of tonsilloliths on panoramic radiographs. MATERIALS AND METHOD: This cross-sectional study was based on 2000 panoramic radiographs from 1030 female and 970 male aged 6-75 years old evaluated for the presence and pattern of tonsillolithiasis, between 2011 and 2013 in Shiraz, Iran. Chi-square test and odds ratio were used to evaluate the relationship between tonsillolithiasis and gender. p< 0.05 was considered as statistically significant. RESULTS: Out of the 2000 individuals, 101 cases (5.05%) had tonsilloliths on panoramic radiographs out of which 61 were male (60.4%) and 40 were female (39.6%), with age range of 18 to 65. Forty patients (39.6%) had both left and right sides involved, 25 of tonsilloliths (24.75%) were located on the right and 36 on the left side (35.65%). Men were more likely to develop tonsilloliths (p= 0.014). CONCLUSION: Tonsilloliths are not very common finding and can be detected on nearly 5.05% of panoramic radiographs. Most of the cases are unilateral with a diameter less than 2mm.