Would Exilis help with my under chin area. I'm 29 year old and I only weigh 105 lbs.

Dear jeannetteer:
Thanks for sharing your photos. They are useful.

Since I do not have the advantage to examine you, I hope you will be helped by the information below. My immediate recommendations are to obtain consultation with a talented, Board Certified Plastic Surgeon with extensive skills in non-surgical and minimally invasive procedures for the neck and jowl.
Options include: 

1.    Minor Surgical options includes:

“Mini” lipo-contouring of the submental chin area, jawline and if desired the lower cheek. 
This is often  combined with ThermiTIGHT, a radio-frequency needle sized probe placed under the skin with local anesthetic to directly contract the skin.
2.    Non-Surgical procedure:
     
Fat freezing using the CoolSculpting Cool-Mini applicator for under the chin and jowl / jawline.

3.  My experience with energy-based trans-cutaneous “laser, ultrasound or radio-frequency” options like Exilis,  Thermage and others for fat reduction and skin tightening has been underwhelming. Patients find them too hot and therefore cannot complete the procedure or find less than satisfactory results. Patients of color may also experience pigmentation changes.



I hope this has been useful! All the best!

Hello there,
      It is difficult to assess this area without being able to examine the tissue. That being said, if there is submental fat in the area, I would recommend a combination of treatments. 
Kybella to reduce any submental fat.
Ultherapy or Exilis Ultra to stimulate deep collagen and elastin to tighten and tone the tissue. 
The combination of these treatments will give you the most impressive improvement. It will help to "clean up"  and chisel the jawline. I especially love the Ultherapy or Exilis approach because these treatments can be seen as an investment in your skin. By stimulating that collagen and elastin, you are reversing the aging process, and giving yourself more collagen and elastin to draw from down the road. I would recommend discussing this with a professional. 
Sarah RN BSN