فراواني وجود فرورفتگي سيگموييد داخلي در راديوگرافي پانوراميك براساس طبقه بندي اسكلتال بيماران ارتدنسي

Frequency of Medial Sigmoid Depression in Panoramic View of Orthodontic Patients Based on Facial Skeletal Classification

Introduction: One of the normal landmarks in panoramic radiograph is in upper portion of mandibular ramus, which is termed medial sigmoid depression. Prevalence of this normal fording may be variable in different skeletal classification. Because this area is thin, it may also increase the potential for complications in orthognatic surgery if this area is involved. Objective: Comparing the orthodontic patient based on facial skeletal classification was objective point of this study. Materials and Methods: In this study, 465 panoramic and lateral cephalometric views of patients (Including 236 c1.I, 141 cl.Il and 88 cl.III patients) before orthodontic treatment were evaluated. Planmeca 2002 EC Proline Panoramic Machine provided all of radiographs. Angle classification was done by some orthodontists through study of cephalometry and consideration of their patientsʹ clinical status. Then panoramic radiographs were evaluated to determine present or absent of finding of medial sigmoid depression on RT and LT sides and categorized this fording to" Marked" and "slight" criteria. Results: According to present study, prevalence of this depression was more common in skeletal cl.Il (RT: %38.8, LT %39) and cl.III patients (RT: %23.9, LT: %38.6) in comparison with cl.I group (RT: %21.6, LT: %26.7) thus this finding has relationship with facial skeletal abnormalities. There was no correlation between this finding and side of involvement. No significant statistical difference was observed between the radiographic criteria of this depression in different skeletal classification. Conclusion: High prevalence of medial sigmoid depression in patient with skeletal problem and more needs to orthodontic surgery in these groups were The most important results of consideration and attention to this area before mandibular osteotomies for prevention of any side effects.