From your description, it sounds like something BOTOX would not be helpful for. In general BOTOX may improve lines in the face that are from muscular activity. What you describe may be helped by the "off-label" use of a filler like Juvederm. The nasal tip is in general made of two cartilages. If those cartilages are separated, particularly in patients with thinner skin, it can create the appearance of a cleft or indentation. The can be described as a "bifid" tip. There are a number of facial "fillers" that may be helpful and can be done as an office procedure. If you decide to have a consultation look for an experienced injector, who also does nasal surgery. A member of ASAPS or ASPS is a good place to start.