A Clinical Study On The Display Of The Anatomy Mark Of The Mandibular Posterior Area In Digital Orthopantomography

Objective To analyze and measure the display of the anatomical markers of the mandibular posterior area in digital orthopantomography, and to study approach and depth of extraction of impacted tooth, orthognathic surgery and dental implantationMethods Siagon were studied before experiment to find out the proper position of X-ray and measure magnify ratio. Standardized digital orthopantomographys were taken for 100 subjects (38 male and 62 female) with an average age of 38.2 years.All X-ray images were taken with sirona orthophos plus DC ceph and were dealed with digital computer. Anatomy markers of the mandibular posterior area were observed and measured by the computer.Results Position of the mental foramen was similar between the two sides; But it was obviously different individually. 2% of mental foramen was below the middle of mandibular body and 98 % above. Mandibular canal of 42 patients could be found out in the orthopantomographys, height of left mandibular body at mental foramen area was similar to that of the right, the biggest difference is 17.51mm. The distance between mandibular canal and root point at mandibular molar area decreased gradually from forth to back. The display ratio of both margins of mandibular canal was 68%,only lower margin 28%,none 4%. There was no obvious difference...