Can Kybella be used along the jawline? (photo)

That is a great question.  The short answer to your question is no.  The long answer: the marginal mandibular branch of the facial nerve travels in that area and supplies the muscles of the lower lip and chin.  This nerve could be injured by the Kybella injection, which could damage the protective cover of the nerve and lead to weakness of the muscles of the lower lip and chin.  This nerve injury was less common in the clinical trials (4%) and all cases did eventually recover but a few patients were reported to take up to a year.The submandibular glands are also in that area:"To avoid potential tissue damage, KYBELLA should not be injected in close proximity (1-1.5cm) of salivary glands" per the labeling instructions that come with Kybella.So the "zone 2" that you show is a No Fly zone for Kybella.  Proper injection of Kybella in the central area does seem to give some effect laterally- one of the potential downsides of the cool mini is that it may not taper as well to the sides of the applied area.

Dear FrenchGarcon:
I love your illustration. Fullness under the jawline can be reduced with Kybella. When injecting, the physician will inject no closer than 1.5 cm to the jawbone itself, to avoid coming close to the marginal mandibular nerve which is tucked up underneath the jawbone, and no closer than 1 cm to the sternocleidomastoid muscle. An 0.2 cc aliquot of Kybella diffuses 1 cm in all directions, and will not approach the nerve. When you reduce the fat in this area, the jawline itself acquires more definition. This is an off-label area, but experienced injectors have found that patients are much happier when any excess fat is treated on the sides of the neck as well as just under the chin.
I will be demonstrating this technique on a male neck this Wednesday between 5 and 7, as well as offering complementary consultations and special pricing on Kybella, Ultherapy and other treatments. 
All the best,  Dr. Clark