Sherif Kandil

Ask any aligner manufacturer for its refinement rate and the answer is 'around 20%.' Dr. Sherif Kandil, CEO of K Line Europe, explains why that number rarely survives scrutiny: case complexity gets blended into one figure, and open cases are counted before they have had a chance to refine. A 2024 study of 2,937 treatments found roughly 70% needed at least one refinement, rising to 82% among the most experienced clinicians. Here is how to measure the rate honestly, and what the gap costs.

A crystal clear aligner in your hand can still glare on the teeth. Dr. Sherif Kandil breaks down the optics behind aligner transparency: why glossy finishes throw a visible highlight, why a slightly foggy aligner often disappears better in the mouth, and why the mirror under normal light is the only test that matters. With a refractive index near 1.5 and light transmittance above 92 percent, material clarity is not the deciding factor. Surface finish is what makes an aligner invisible.

Every year, 20 million new orthodontic cases start worldwide, but the real story lies beneath that number. Contrary to popular belief, clear aligners still represent only 25% of global treatments, while brackets hold a commanding 75%. Even more striking, one single company controls over half the aligner market. So who fills the gap? And what does the "missing middle" mean for the future of orthodontics?