A Morphological Study on Human Mandible
-Radiographical Analysis in Alveolar Bone-
2000 Volume 13 Issue 2 Pages 310-320
Details
2000 Volume 13 Issue 2 Pages 310-320
The purpose of this study was to evaluate methods available for estimating changes in various conditions of bone minerals and structure of mandible using X-ray image.
Four specific and conventional techniques were performed for determining bone density:
1. Specific instrument of bite-block for constant condition of X-ray films in clinical treatment.
2. Correcting contrast for bone loss on teeth against background noise on X-ray films using a control marker.
3. Detail images of X-ray density using a microscope.
4. Detail analysis using a computer system.
Specimens were collected from 26 cadavers (18 males, 8 females, 40～90 years old) which had no injuries to the alveolar bone. One hundred sixty-two X-ray films of other specimens were collected during clinical treatment.
Radiographic bone density on four types (type 1, dentious jaw; type 2, molar teeth loss; type 3, first molar or premolar teeth loss; type 4, edentulous jaw thick of jaw body; type 5, edentulous jaw, thin jaw body) were analyzed.
Type 1:The density of bone mineral was low in the alveolar crest bone, which showed irregularly arranged bundle-like bone matrices forming complex networks when soft X-ray instruments were used.The X-ray computer system showed that the level of density increased gradually to the inner region of the mandible.
Type 2: The density of bone mineral of alveolar crest bone was high, and numerous fine complex bone matrices formed networks in the upper basal bone around the mandibular canal. The levels of mineral density gradually increased from alveolar bone to the basal region of the mandible.
Type 3: Complex networks were found in the alveolar bone oriented at right angles to the surface of the mandible. The level of density tivas low at 6 mm below the surface.
Type 4: Compacted mineral matrices were found in the alveolar crest. The level of density increased to 10 mm below the crest.
Type 5: The level of density was only high at the basal portion of the mandible.
The results suggested that the structure of the alveoler crest bone is related to the density of bone mineral in human mandible, and may provide useful information for implantation.
