Guided bone regeneration of a pronounced gingivo-alveolar cleft due to orthodontic space closure.

Background: Gingival invagination is a relatively common occurrence following orthodontic closure of extraction sites. The present paper reports a combined periodontal and orthodontic treatment in a patient with a severe gingivo-alveolar cleft due to orthodontic closure of maxillary central incisor extraction space.

Methods: A definite interdental gingival cleft, extending 8 mm into the alveolar bone, required the correction of the gingival deformity as a first step, followed by guided bone regeneration (GBR).

Quantification and localization of platelet-derived growth factor in gingiva of periodontitis patients.

Background: Platelet-derived growth factor (PDGF) is a mitogen and chemoattractant for cells of mesenchymal origin. Over-expression of PDGF-B can promote formation of inflammatory lesions in the lungs of transgenic mice. Moreover, continuous exposure to PDGF inhibits collagen production by osteoblastic cells.