Do I need jaw surgery, or would chin implant/genioplasty be sufficient? (photos)

Hello, thank you for your question. You may benefit from jaw/chin implants, an in-person examination is needed, I recommend you to schedule a consultation with a board certified plastic surgeon.

Thank you for your question and sharing your photographs.
It seems to me that a genioplasty procedure is likely to produce a deeper groove between the lower lip and chin.
Chin implant, and in particular a Medpor chin implant is not likely to create this problem because it has the ability to build support in projection closer to the labiomental sulcus.
It is also possible to use filler or fat transfer to build slightly more volume between the chin and lower lip and create a smoother transition.

See an Orthognathic Craniofacial Surgeon in Glasgow who may be able to help. You may be able to have some orthodontic compensation/camouflage your ‘underbite’, in addition to a chin implant or genioplasty.

For your chin augmentation either an implant or sliding genioplasty would work, the difference between the two depends on what type of aesthetic result you are seeking. Each chin augmentation method has some subtle differences in its effects. Computer imaging will help you determine those differences. But the similarity all methods of chin augmentation share is that the labiomental fold will get a bit deeper as the chin below it comes forward.