| 摘要 |
<p>A toothbrush comprises a toothbrush head section with a toothbrush shaft and toothbrush bristles fixed on the toothbrush shaft. The toothbrush shaft has a front tip and bristles, which can reach the hard-to-brush areas in the back of a person's molars. The bristles on the toothbrush shaft are at an angle of υ which is less than or same as 90 degree. The bristles set at an incline of approximately 30 degree to 89 degree are near the front tip of the toothbrush head, therefore, at this angle, the bristles extend beyond the length of the front tip of the toothbrush head.</p> |
