[Fluorescence angiographic diagnosis of the elasticity of the labial frenum].

The fluorescein angiographs of the attached gingiva of 10 out of 12 subjects showed distinct areas of ischaemia which were clinically not discernible when standardized tensions of 100 g or 200 g tensions were exerted on the mandibular frenum. The fluorescein angiographs were reproducible in 3 out of 4 cases and the ischaemic areas reached the adjacent gingival margins in 5 cases. Possible hypoxic damage of the periodontium by tension of frenum is discussed.