I am very skinny so why does my jawline disappear into my neck? (Photo)

A better set or set of facial photographs are going to be required to make a determination about how best to proceed. Liposuction in the neck along with a platysma-plasty can accomplish improvement.

Your own imaging shows enhancement of the corners of your jawline, the chin and the jaw angle in profile. The amount of enhancements are not large but visible. You should be able to achieve these changes with standard chin and jaw angle implants. 

Personally I think you have a nice Jawline  and shouldn’t be too concerned.In general when thin young people have a double chin or lack definition the primary reason is skeletal. Most of the time these people have a mandible that is smaller or lacks projection.Your mandible  is actually fairly substantial and has quite a bit of vertical height.Your maxilla or mid face does have quite a bit of projection. Your face is relatively thin compared to its vertical height.I don’t recommend a sliding genioplasty. You do not need downward projection and I question if forward projection would create the appearance of a masculine profile. You could try working with fillers augmenting the corner of the mandible or giving slight forward projection. Liposuction also works really well but obviously it depends on the amount of fat available to make a difference.Probably reassurance is the best option but if you want to look into surgical options then you will need in person consultations. Please look for senior plastic surgeons who have years of experience and service patient advocates serving your needs before lining their pockets.If you walk into and plastic surgeons office asking for an operation there’s a good chance you’re going to be offered one.Other providers who may be good at this include oral surgeons and facial plastic surgeons.During consultations you want a provider to talk about your entirDuring consultations you want a provider to talk about your entirefacial skeleton and not just focus on the jawline or the chin. The assessment should include relationshipsWith the rest of the face.Fillers are always a safe place to start but can get in the way in regards to making assessments for surgical intervention.Personally I would avoid Kybellaand cool sculpting.Best, Mats Hagstrom MD

You have a more vertical facial growth pattern which usually has a narrow lower jaw. The angles if the jaw are closer to the ear height creating a higher slope. Augmentation of the jawline from the angles to the chin does yield a very positive jawline definition.