در افراد داراي صورت با ارتفاع طبيعي POSTERIOR CRANIAL FOSSA بررسي ارتباط پلان منديبول با تحتاني ترين نقطه

A study of relationship between mandibular plane and the most inferior point of posterior cranial fossa in patients with normal facial height

Introduction: Among several cephalometric analyses used in orthodontics, none of them could present all diagnostic and interpretative featwres. The aim of this study is to apply a simple and convenient approach which could enable the orthodontists to gain maximum information from it . Materials and Methods: Cephalograms of 58 adults patient (40 femals and 18 males) with mean age of 15 years and 4 months, were used for analysis. After tracing , the relationship between mandibular plane and the most inferior point of posterior cranial fossa was assessed. Results: The data revealed that: -SNA and SNB were less than norms which was not significant. - In patients with normal facial height, extention of mandibular plane lay lower to posterior cranial fossa and the mean distance was 6.84 mm. -Mp-Ar-N Angle was 42° to 55° (49 ± 6) that was 2° less than Norms. Conclusion: Extention of mandibular plane to posterior cranial fossa or lower, shows that there is a failure in vertical growth.