ABSTRACT
Aim: This study evaluated radiographic variations and measured dimensions of the non-pathologic frontal sinuses. Study Design: Retrospective. Place and Duration of Study: Orthodontics Department, Dental School, Shahid Beheshti University of Medical Sciences, 2003 to 2012. Methodology: Subjects older than 12 years with no sinus pathology were included. Borders of the frontal sinus were traced. Line drawings were scanned, and sinus dimensions were calculated by computer software by two examiners. In addition, asymmetry and shape of superior margin of sinus were evaluated. Gender differences were analyzed by independent sample t-test and chi square with a 0.05 level of significance. Results: A total of 66 subjects were included (40 female and 26 male). Height, width and area of the frontal sinus in the sagittal plane were 2.26 cm, 1.13 cm and 1.37 cm2, respectively. The corresponding numbers in the frontal plane were 2.79 cm, 5.00 cm and 7.04 cm2, respectively. Although all dimensions were larger in men than in women, it was not significant (P>0.05). Most of the cases had relatively symmetric frontal sinus. Conclusion: Size and shape of the frontal sinus varies among individuals. Frontal sinus is relatively larger in men than women.
ABSTRACT
Aims: Expanding mandibular arch for correcting transverse deficiency is a challenging problem in orthodontics. It is believed that mandibular symphyseal distraction osteogenesis (MSDO) is an attractive solution for this problem. The aim of the present study is to review available data regarding stability of MSDO and its effect on temporomandibular joint and teeth and their surrounding tissues, in a systematic approach. Study Design: The study is a systematic review of available evidence. Place and Duration of Study: Department of Orthodontics of Dental school at Shahid Beheshti University of Medical Sciences. From January 2014 to January 2015. Methodology: Electronic searching was done in Medline, Embase and CENTRAL databases. Published clinical studies and case series in English language which had used tooth borne, bone borne or hybrid distractors and had follow up period of 1 year or more were included. Review article, case reports, and letters were not included. Presence of samples with syndromic problems or mandibular cleft and simultaneous other surgical procedures in mandible were reasons for excluding articles. Data were extracted from selected articles. Risk of bias was assessed in articles. Results: A total of 77 articles were found, from which, 10 met the inclusion criteria. 5 articles had assessed stability and none had reported instability. The effect of MSDO on temporomandibular joint was evaluated in all of the included studies, all of them stating that MSDO would not cause permanent changes in temporomandibular joint status. Gingivitis, root injury, mobility, pseudopocket and irresponsiveness to cold stimulus were reported in 6 studies. Risk of bias was assessed to be high in the included studies. Conclusion: Within the limits of this review it is concluded that MSDO would be a stable procedure and it may not cause temporomandibular joint disorder, provided that proper technique is used. Risk of injury to tooth is not so common; however, great care should be taken in order to prevent these injuries. Well-designed randomized clinical trials are highly recommended to clarify these issues.