Page 76 - 根管治療的美麗與哀愁 (柒部曲)
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ྡ79Y Ԓމ࣬၍ਖ਼߅d࿁яତतମ
၍ഢஷ༸ࣩٙԷdεˇேึϞ್
ːਗeᚔᚔ૧༊ٙಂܙi್Ͼd߰
ڢ̈ତ๕ष೨dᒔ݊ਗ਼ː
ˢːdйЪՍจʧɝطᐕ
ORAL PATHOLOGY Clinical Pathologic Correlations (by Regezi, Sciubba, Jordan)
4th edition Chapter 16 Abnormalities of Teeth p.368
Fusion is the joining of two developing tooth germs, resulting in a single large
tooth structure. The fusion process may involve the entire length of the teeth, or it may
involve the roots only, in which case cementum and dentin are shared. Root canals may
also be separate or shared. It may be impossible to differentiate fusion of normal and
supernumerary teeth from germination. The cause of this condition is unknown, although
trauma has been suggested.
Germination is the fusion of two teeth from a single enamel organ. The typical
result is partial cleavage, with the appearance of two crowns that share the same root
canal. Complete cleavage, or twinning, occasionally occurs, resulting in two teeth from
one tooth germ. Although trauma has been suggested as a possible cause, the cause of
germination is unknown. These teeth may be cosmetically unacceptable and may cause
crowding.
64 ʔᓙіϗอٝdܵᚃᔳ᜕ᗇdڦԒଡ଼ᔌٙᆑঐ
