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The primary (connective tissue papillae) and secondary projections of the subepithelial connective tissue of the lamina propria were studied in the hard palate of normal (control group), and in protein-deficient pups (experimental group) obtained through maternal protein deprivation during pregnancy and lactation. At birth, the primary projections in the control group are more developed in width whereas in the experimental group they are thin with a crest-like shape. On day 7 of lactation, the primary projections are abundant, well developed and regularly arranged in the control group. They are few in number and are irregular in shape and disposition in the experimental group. The secondary projections are located posterior to the primary ones in the control group and are intercalated with them in the experimental group. On day 21 of lactation, the characteristic foliate aspect of the primary projections are noted in the control group. In the experimental group they remain thin with a crest-like aspect.

Morphological features of the mid-palatal suture were studied in human foetuses from 4 to 9 months of intra-uterine life. The foetuses were divided into three age groups, GI (16-23 weeks), GII (24-31 weeks) and GIII (32-39 weeks). The mid-palatal suture in GI foetuses is rectilineal in form with a wide space between the palatal processes of the maxilla. The suture has a sinuous nature in GII and GIII foetuses due to growth of the bone processes crossing the mid-line. A wide zone of cellular proliferation observed in GI narrows in GII and GIII foetuses. The imbricating nature of the suture in GII and GIII is caused by bone growth adjacent to the mid-palatal suture. Sharpey's fibres, emerging from the bone processes, run to the median region of the mid-palatal suture and are observed from GI foetuses onwards. The collagen fibres of the mid-palatal suture are orientated transversely under the oral epithelium and exhibit a regular meshwork with a predominance of sagittal fibres in the median region of the suture. These fibres are orientated transversely and obliquely at the junction with the nasal septum.

In order to verify the effects of CO2 laser on the palatine mucosa of rats, 15 animals were utilized. The animals were anaesthetized with thionembutal by intra-peritoneal injection and the palatine mucosa of each animal was irradiated with a single pulse of 10 W. The results showed that immediately after the irradiation of CO2 laser, the formation of small cavities is observed. The wound healing post operationem is gradually in 1 week. The region is totally occupied by neoformed connective tissue and epithelial cells. Numerous polymorphonuclear cells and fibroblasts may be seen between the neoformed collagen fibres.