What is the best procedure to make a long face shorter? (photo)

It appears in the profile photo that your chin is short in the vertical plane. A vertically lengthening sliding genioplasty would provide improved facial balance and make the chin appear more slender and narrow and feminine.

Chin advancement with narrowing will provide a more feminine chin. The chin needs to come forward and reduced in width. This is accomplished with a sliding genioplasty.

Dynamic changes to the chin are difficult to correct. Neuromodulators like Botox tend to help with a hyperactive Mentalis muscle. A small advancement genioplasty will provide better lower facial balance but may not completely prevent the downward positioning of the chin pad when smiling.

If you want to affect your chin position, do them at the same time. If you have bite issues, or want to change your teeth position, I'd do all jaw surgery first.

The horizontal projection of your chin looks about right. The shape can be altered by shaving the width of the chin to make it less square. In addition, I would recommend simultaneous submental liposuction to improve the cervical-mental contour.

These 2 surgical procedures can be performed simultaneously or as separate procedures. The genioplasty will improve your jawline from front to back. In addition, the angle between your neck and chin will improve as the chin is positioned forward and balances the lower face.