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

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

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 Bron-stein 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 ANO VA/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

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

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