Morphometric study of the interproximal unit in the esthetic region to correlate anatomic variables affecting the aspect of soft tissue embrasure space.

BACKGROUND: The presence of a normal papilla is crucial to avoid the unpleasant esthetic defects that are of major concern to periodontists, restorative dentists, and patients. During the course of progressive periodontitis and following periodontal treatment, it is not uncommon to have a partial loss of the interdental papilla. This loss can lead to an unesthetic gingival appearance. This study evaluated different anatomic variables in an effort to determine their role in the papillary appearance of maxillary incisors. METHODS: A total of 178 interdental embrasures in 58 patients were selected randomly for examination. For each patient, a digital photograph and a modified periapical radiograph of the interdental embrasure of the four maxillary incisors were taken by using a special metric device fixed to a centrator as a reference marker. Clinical and radiographic data were obtained for the distance from the contact point to the alveolar crest and for the interradicular distance. We used a classification system with regard to peri-implant soft tissue based on esthetic assessments related to the space between reference lines through the highest gingival curvature of the crown-tooth margin and the contact point. RESULTS: In the group of interdental sites with an interradicular distance of less than approximately 2.4 mm, an increase in the distance between the contact point and the bone crest corresponded to a marked increase in the interdental black triangle's dimensions and, therefore, a less esthetic smile. In particular, when the interradicular distance was >2.4 mm, we statistically estimated that the other anatomic variable considered, the distance from the contact point to the alveolar crest, lost its influence on whether the interdental papilla would be present or absent. CONCLUSION: The interradicular distance and the distance between the contact point and the alveolar crest have independent and combined effects on the presence or absence of the interdental papilla.

Alpha-melanocyte-stimulating hormone antagonizes the inhibitory effect of corticotropin-releasing hormone on luteinizing hormone secretion during the luteal phase in normal women.

CRH inhibits the secretion of gonadotropins by activating endogenous opioids, whereas alpha MSH, which displays various behavioral and neuroendocrine effects contrary to those of the opioids, stimulates their release. To evaluate the possible interaction of CRH and alpha MSH, eight women in the luteal phase underwent the following tests: 1) ovine CRH infused at 100 micrograms/h for 3 h, 2) alpha MSH (2.5 mg as an iv bolus 60 min after the start of saline infusion), 3) CRH plus alpha MSH (injected 60 min after the start of CRH infusion), and 4) placebo. LH, FSH, PRL, ACTH, and cortisol were determined every 15 min for 180 min. CRH significantly (P < 0.001) reduced serum LH. alpha MSH alone significantly (P < 0.001) increased LH to a peak within 15-30 min (baseline, 3.3 +/- 0.7 mIU/mL; maximum increase, 3.5 +/- 0.9 mIU/mL) and induced an even greater rise when injected during the CRH infusion (baseline, 2.8 +/- 03 mIU/mL; maximum increase 7.5 +/- 1.6 mIU/mL; P < 0.05 vs. alpha MSH alone). FSH was always unaffected. ACTH and cortisol increased (P < 0.001) during the CRH infusion and fell significantly (P < 0.001) during the placebo infusion. alpha MSH had no effect on these changes. PRL fell during the placebo infusion (P < 0.001). No changes were induced by CRH or alpha MSH. In conclusion, alpha MSH antagonizes CRH inhibition of LH secretion. This finding lends support to the view that differential posttranslational processing of POMC contributes to the regulation of LH secretion. Further investigation is needed to clarify the mechanism of the antagonism between alpha MSH and CRH.