one of the most common positioning errors in panoramic radiography is palatoglossal air space above the apices of the root of maxillary teeth. it causes a radiolucency obscuring the apices of maxillary teeth. in the case of this positioning error, the imaging should be repeated. this causes the patient be exposed to radiation again. to avoid the repetition of exposing harmful x-rays to the pati...

This paper summarizes three algorithms used for the analysis of gray level histograms. Two of them are easily developed from standard techniques and the other is a completely new method. We will study the advantages of each and give examples of real-world use. Gray level histogram analysis (mainly threshold computation) is a known technique that allows easy and fast segmentation of the regions ...