Analysis of Pharyngeal Airway Using Lateral Cephalogram vs CBCT Images: A Cross-sectional Retrospective Study.

Background : As the basic biological relationship of form and function, changes in the normal pattern of nasopharyngeal space can profoundly affect the development of the craniofacial growth. The lateral cephalogram, part of the patient's normal records for orthodontic treatment, may show some of these changes either at the initial examination or later during treatment. The validity of the information the lateral cephalogram may present, have been questioned previously. The aim of this study was to assess correlation between the area and the volume measurements of pharyngeal airway size in a lateral cephalogram and a 3-dimensional (3D) cone-beam computed tomography (CBCT) scan in adolescent subjects. Materials and Methods : CBCT scan and a lateral cephalogram of 35 subjects which were taken within 1 week were included in this study. Airway area of the region of interest from the lateral cephalogram and airway volume over the same of region of interest from the CBCT scan were assessed for all patients. The correlation between the area and the volume measurements were evaluated statistically by Pearson's correlation coefficient test. Mann Whitney U Test was used for comparing the area and the volume measurements in different sex. Results : Strong correlation was found between lateral cephalogram and CBCT measurements of pharyngeal airway. (r=0.831). Conclusion : Pharyngeal airway area on a lateral cephalogram is correlated strongly with volumetric data on CBCT images. Henceforth the use of CBCT images for volume measurements in orthodontic patients can aid in the better evaluation of airways and acted as a diagnostic instrument in this area.

Prevalence of bifid mandibular condyle in a selected population in South of iran.

STATEMENT OF THE PROBLEM: Bifid mandibular condyle (BMC) is a rare anomaly of uncertain origin which may play a role in some defects in temporomandibular joints. Since it may be misinterpreted as fractures or tumors in condylar area, proper diagnosis will help to prevent unnecessary treatments. A comprehensive knowledge about BMC may help to understand the developmental course of condyle and temporomandibular joints more clearly. PURPOSE: The purpose of this study was to estimate the prevalence of bifidity of condyle in a selected population in Iran by employing dental panoramic view. MATERIALS AND METHOD: Panoramic views of 1000 individuals (767 female, 233 male individuals) were assessed for bifidity. The patients were over 18 years old and had attended the radiology department of Shiraz dental school from September 2012 to March 2013. RESULTS: A total of 35(3.5%) case of bifidity was detected. Unilateral form was much more prevalent (32 unilateral cases versus 3 bilateral). The left-side bifidity was 3 times more prevalent than the right side. A large number of bifid condyles (63%) have shown symptoms of temporomandibular joint pain or click or both. CONCLUSION: The prevalence of bifidity in our population was about 3.5%, which was significantly high compared to the other published reports. Symptoms (click and pain) were also much more detected in our study.

Accuracy of linear vertical measurements in posterior mandible on panoramic view.

BACKGROUND: One of the most frequent concerns encountered in dental implant treatments is inadequate pre-operative planning. Panoramic radiographs are readily accessible and cost efficient. The aim of this study is to assess the accuracy of vertical measurements in mandibular molar and premolar region on panoramic radiography. MATERIALS AND METHODS: Panoramic radiographs were made of a partially edentulous sheep mandible mounted in acryl. Measurements collected from the computer-generated images were compared to measurements made directly on the cross-sectioned hemi-mandibles using t-test. P < 0.05 was considered significant. RESULTS: The results show that panoramic image is overestimated in predicting the linear measurements in posterior mandible. By applying the magnification factor of 1.29 the difference became insignificant. CONCLUSION: It seems rational to use panoramic radiography for pre-surgical implant assessment of posterior mandible if a true magnification factor is applied.

Comparison of panoramic radiography with cone beam CT in predicting the relationship of the mandibular third molar roots to the alveolar canal.

PURPOSE: Preoperative radiographic assessment of the mandibular third molars is essential to prevent inferior alveolar nerve damage during extraction. The purpose of this study was to assess the reliability of panoramic signs of association between the roots of teeth and the canal, and to compare the panoramic signs with cone beam computed tomography (CBCT) findings. MATERIALS AND METHODS: CBCT images of 132 impacted mandibular third molars were evaluated to determine the association of the root to the canal. The CBCT findings were compared with the corresponding panoramic images. Logistic regression analysis was used to define the diagnostic criteria of the panoramic images. RESULTS: AMONG THE PANORAMIC SIGNS, LOSS OF THE CORTICAL LINE WAS THE MOST FREQUENT RADIOGRAPHIC SIGN PREDICTING ASSOCIATION (SENSITIVITY: 79.31). Contact of the tooth with the canal was observed in all cases in which the loss of cortical line of the canal or darkening of the roots was found on the panoramic radiographs. CONCLUSION: Darkening of the roots and loss of the cortical line on panoramic radiographs might be highly suggestive of the risk of nerve injury.

Can dental pulp calcification predict the risk of ischemic cardiovascular disease?

OBJECTIVE: To report the association of pulp calcification with that of cardiovascular disease (CVD) using digital panoramic dental radiographs. MATERIALS AND METHODS: Digital panoramic radiographs of patients referred from the angiography department were included if the patient was under 55 years old and had non-restored or minimally restored molars and canines. An oral and maxillofacial radiologist evaluated the images for pulpal calcifications in the selected teeth. The sensitivity, specificity, positive predictive value and negative predictive value of panoramic radiography in predicting CVD were calculated. RESULTS: Out of 122 patients who met the criteria, 68.2% of the patients with CVD had pulp chamber calcifications. Pulp calcification in panoramic radiography had a sensitivity of 68.9% to predict CVD. CONCLUSION: This study demonstrates that patients with CVD show an increased incidence of pulp calcification compared with healthy patients. The findings suggest that pulp calcification on panoramic radiography may have possibilities for use in CVD screening.

Prevalence of taurodontism in premolars and molars in the South of iran.

BACKGROUND AND AIMS: The study was undertaken to assess the prevalence of taurodontism and related systemic condi-tions and gender differences in premolars and molars of patients attending Shiraz Faculty of Dentistry. MATERIALS AND METHODS: In this cross-sectional study, panoramic radiographs of 510 randomly selected patients were evaluated by a maxillofacial radiologist for the apically displaced pulp chamber. Detailed medical and family history of the patients was obtained. RESULTS: The prevalence of taurodontism in 510 panoramic views was 5.5% of patients. Females had significantly higher prevalence of taurodontism than men (P>0.05) and mandibular second molar was the most affected tooth. CONCLUSION: Taurodontism was relatively common in population under study. A family history of other anomalies should be checked for affected patients.

Mandibular bone changes induced by head and neck radiotherapy.

CONTEXT: The mandible is inevitably affected by radiation during radiotherapy of head and neck cancers. Surveys have shown that most of the emphasis has been on osteoradionecrosis (ORN), while the other bony changes occurring in this area have been largely ignored. AIMS: In this study we examine the radiologic changes in the mandible of irradiated patients using panoramic radiography and compare it with the mandible in non-irradiated cases. MATERIALS AND METHODS: Mandibular bone changes of 48 patients who had received therapeutic radiation for head and neck cancer were assessed. We measured the width of the cortex and the width of the mandibular canal on panoramic radiographs and assessed the changes by comparison with the mandibular bones of non-irradiated subjects. Clinical evaluations were performed for assessing maximum jaw opening, masticatory muscle tenderness, and presence of mucosal ulcers and/or exposed bone in the oral cavity. STATISTICAL ANALYSIS: Paired t-test, Chi-square test, and Mann-Whitney test were used for statistical analysis. P < 0.05 was taken to indicate statistical significance. RESULTS: There was no evidence of mucosal ulceration or exposed bone in irradiated patients. There was significant relationship between the number of years after radiotherapy and the degree of limitation of mouth opening (P = 0.000). Receipt of concurrent chemotherapy did not seem to have any additive effect on the width of mandibular canal or the thickness of the mandibular cortex. CONCLUSION: Reduction in the width of the mandibular cortex and dimensions of the inferior alveolar canal could be considered as one of the effects of head and neck radiotherapy.

Imaging findings in a case of Gorlin-Goltz syndrome: a survey using advanced modalities.

Gorlin-Goltz syndrome is an infrequent multi-systemic disease which is characterized by multiple keratocysts in the jaws, calcification of falx cerebri, and basal cell carcinomas. We report a case of Gorlin-Goltz syndrome in a 23-year-old man with emphasis on image findings of keratocyctic odontogenic tumors (KCOTs) on panoramic radiograph, computed tomography, magnetic resonance (MR) imaging, and Ultrasonography (US). In this case, pericoronal lesions were mostly orthokeratinized odontogenic cyst (OOC) concerning the MR and US study, which tended to recur less. The aim of this report was to clarify the characteristic imaging features of the syndrome-related keratocysts that can be used to differentiate KCOT from OOC. Also, our findings suggested that the recurrence rate of KCOTs might be predicted based on their association to teeth.