This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
齱 combines 齒 (tooth) with 取 (take). The exact historical development is uncertain, but it likely relates to teeth or taking in a dental context.
The left side is a tooth (齒), and the right side is taking (取). Imagine taking a tooth, but the real meaning is unclear.
For サク, imagine a sack (サク) of teeth being taken away: sack -> サク, tying the reading to the tooth-taking shape.