Can You Straighten Just Your Top Teeth with Spark Clear Aligners?

With Spark clear aligners, you can discreetly straighten your crooked or otherwise misaligned teeth. Most of the time, the aligners are worn on both arches. But what if your upper teeth are crooked while your bottom teeth are properly aligned? Is it possible to get Spark clear aligners for just your upper teeth? And if so, is it truly a good option for your smile?