Also works on "stuck spots" caused by receding gums. The two specially designed curved bristles clean gaps and leave them as clean as if you had just brushed them. Curve 1: The center bristles are convexly curved, allowing them to focus on the jammed spots and push out any debris. Curve 2: The bristles on both sides are concavely curved to fit the tooth alignment. They gently wrap around the teeth and gums, allowing for consistent brushing along the alignment of your teeth. The ultra-fine bristles reach deep into gaps and between the teeth and gums. Ultra-compact.