Morphological study of amelogenesis in the rat lower incisor after thyro-parathyroidectomy, parathyroidectomy and thyroidectomy.
The effects of thyro-parathyroidectomy, parathyroidectomy or thyroidectomy upon enamel formation in the rat incisor were studied. One control group and four groups of surgically treated rats were used: parathyroid autotransplanted, thyroidectomized, parathyroidectomized, and thyro-parathyroidectomized. One month after surgery, the incisors were processed for light and electron microscopy. The present study revealed perturbations of the Tomes process morphology, of the rod pattern in the inner enamel formation, of the enamel surface, and of the mineralization after thyro-parathyroidectomy. After parathyroidectomy, only mineralization defects could be visualised. No effects were observed in enamel after thyroidectomy. A severe hypocalcemic state as seen in thyro-parathyroidectomized rats affects the enamel shape, and mineralization, and the morphology and function of secretory ameloblasts. Knowledge of the way in which the alteration of the enamel surface is produced should contribute to a better understanding of the development of tooth enamel.
Acevedo
A C
AC
Laboratoire de biologie et biomatériaux du milieu buccal et osseux, Université Paris V, Faculté de Chirurgie Dentaire, 1 Rue Maurice Arnou, F-92120 Montrouge, France.
Chardin
H
H
Staub
J F
JF
Septier
D
D
Goldberg
M
M
D000565:Ameloblasts / Q000166:cytology; D000566:Amelogenesis / Q000502:physiology*; D000818:Animals; D001835:Body Weight / Q000502:physiology; D002118:Calcium / Q000378:metabolism; D003743:Dental Enamel / Q000648:ultrastructure; D005260:Female; D007180:Incisor / Q000254:growth & development / Q000502:physiology / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D010280:Parathyroid Glands / Q000502:physiology*; D010281:Parathyroid Hormone / Q000097:blood; D016105:Parathyroidectomy; D010710:Phosphates / Q000378:metabolism; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D013961:Thyroid Gland / Q000502:physiology*; D013963:Thyroid Hormones / Q000097:blood; D013965:Thyroidectomy
D010281:Parathyroid Hormone; D010710:Phosphates; D013963:Thyroid Hormones; D002118:Calcium