[Applying photocclusion method to study occlusion mechanics on wedge  shaped teeth defect with computer assisting].
OBJECTIVE
Study the occlusal force of wedge shaped teeth defect and its relation with the clinical condition.


METHODS
Use the method of clinical examination and plaster model measurement to decide the parameters of axial gradient degree of the teeth, abrasion index, missing teeth number and so on; Adopt the computer image processing technology and program to analyse the photocclusion sheet, take the date and image information of occlusion force, areas, and occlusal stress of wedge shaped teeth defect.


RESULTS
The occlusion contact data and graph of wedge-shaped teeth defect had the features of trauma occlusion. 42.97% of them has the larger axial gradient degree, 96.09% of them has abration in different classes, 46.29% missing the front teeth and 57.03% missing the buccal teeth. Occlusal contact force increase took up 78.91% in the wedge shaped teeth defect.


CONCLUSIONS
It can be concluded that the not uniformly distributed occlusal force produced from the larger axial gradient degree, the defect of dentition, and the abrasion of teeth, may be the important factors which cause wedge shaped teeth defect.
Tang
S Y
SY
Department of Stomatology, Beijing University Hospital, Beijing 100084, China.
Li
M
M
Jin
G C
GC