I have not found any sound studies documenting the benefit of facial exercises to tighten and lift the neck. In fact, clenching or grimacing to tighten the muscles in the lower face and neck will most certainly cause contraction of the platysmal muscles, which run along the jawline from ear to ear and anchor on the collar bone. This will cause a downward pull giving the appearance of sagging along the jawline along with the appearance of vertical bands in the neck. All in all, not a pretty look. In fact, Botox and Dysport are commonly used off-label to soften the platysmal bands, giving the neck a smoother and more appearance.