Relationship between bridging and dimensions of sella turcica with classification of craniofacial skeleton

Purpose: In orthodontics, it is essential to determine the craniofacial skeleton pattern (class I, II, III) for planning treatment. Sella turcica bridging that is seen on lateral cephalometric radiographs is considered as a normal finding. This study aimed to compare sella turcica bridging and its dimensions in patients with various craniofacial patterns. Material and methods: A total of 105 lateral cephalometric radiographs (53 men and 52 women), aged 14-26 years, were randomly and equally assigned to three groups of class I, II, and III, respectively. The length, diameter, and depth of the sella turcica as well as sella turcica bridging were determined on radiographs. The chi-squared test was used for assessing the relationship between sella turcica bridging and craniofacial skeleton classification. ANOVA was used for assessing the relationship between the dimensions of the sella turcica and craniofacial skeleton classification. The Pearson's correlation coefficient was used for assessing the relationship between age and the dimensions of the sella turcica. Results: The sella turcica had a normal shape in 64.76% of patients, whereas 35.33% of patients had sella turcica bridging. In total, 11.42% of patients belonged to class I, 34.28% to class II, and 66.62% to class III. The diameter of the sella turcica had a significant relationship with age; the diameter of the sella turcica increased with age (p < 0.001). Conclusions: There is a significant relationship between craniofacial skeleton patterns and sella turcica bridging, i.e., the incidence of sella turcica bridging is higher in class III patients. The sella turcica had a greater diameter in older patients

Accuracy of mandibular vertical linear measurement in panoramic and tomography images

Introduction: The measurement precision of jaw is important for surgery or installing implants. Preimplant radiographs are important part of clinical evaluations before implant surgery. For choosing location, we should consider the important anatomical structures like mental foramen, inferior alveolar canal, nasal cavity and maxillary sinus.It is important to know the measurement accuracy of radiographic techniques. The purpose of this study was to compare mandibular vertical linear measurement in panoramic and tomography images. Methods: Three forms of mandible from dry adult human skulls were used in this study (triangle, square and ellipse). For each mandible, surgical stent was made using transparent with gold standard.acryl. A thin tube was placed in the stents in three regions (incisors, premolars and molars) to set gutta-percha. Then, the panoramic view and conventional tomography were obtained. Four oral and maxillofacial radiologists measured the vertical dimension in panoramic and conventional tomography. Finally, each mandible was sectioned in the marked sections and was measured by a digital caliper (gold standard) and compared with conventional tomography and panoramic view .The obtained data was analyzed using SPSS18 software and student t-test, Pearson correlation coefficient and non parametric Mann-Whitney Test. Results: The mean difference between the panoramic and gold standard linear vertical dimension values in premolar and molar regions was above 1mm and above 2mm in incisor region. The mean difference between conventional tomography and gold standard measurements in all three regions was 1mm. Conclusions: The linear measurement of vertical dimension in conventional tomography was more precise than panoramic. The use of a 2.0 mm safety margin in the evaluation of implant sites was recommended.In incisor area, the other radiography methods like CBCT was suggested

Prevalence and Ossification Variation of Stylohyoid Ligament on Digital Panoramic Radiographs

Background and purpose: The elongation of styloid process can result in Eagle syndrome. The purpose of this study was to investigate the prevalence and pattern of ossification of elongated styloid process (ESP) in digital panoramic radiography and their association with gender and age. Materials and methods: In this retrospective study, 400 digital panoramic radiographs of patients attending Oral and Maxillofacial Radiology Department in Mazandaran University of Medical Sciences were examined. The length of the styloid process was measured and classified into elongated, pseudoarticular, and segmental types. Length equal to or greater than 30 mm was considered as an elongated styloid process. Data were analyzed in SPSS using Chi-square, t-test, and correlation test. Results: Radiographs of 400 patients including 167 (42%) males and 233 (58%) females aged 11-79 (38.13 ± 48.43) years were investigated. ESP was observed in 118 (29.5%) patients. The prevalence of ESP was significantly higher in males (50.8%) than females (49.1%) (P=0.016). Also, the prevalence of ESP was significantly higher in older adults (P<0.001). Among the types of ESP, type I was found to be more prevalent. Conclusion: Elongated styloid process was relatively common in the population studied and was significantly correlated with age and sex (more prevalent in males)