Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Align Technology (NASDAQ:ALGN), a medical device and software design company for the dental and orthodontics industry, jumped as much as 12% after reporting better-than-expected second-quarter results.

So what: For the quarter, Align reported solid growth in sales of its Invisalign clear aligner (by far, its primary revenue generator), which helped propel revenue higher by 12.5%, to $163.8 million. Profits grew by a tamer 3%, to $0.36 per share; but this was still higher than last year's $0.34 in EPS, and considerably higher than the $0.28 per share Wall Street had been expecting. The company did, however, note that it changed its policy to no longer charge its customers for so-called mid-course corrections. In the second-quarter, for instance, it reduced revenue by $2.7 million. Looking ahead, Align is forecasting $154.9 million to $160 million in sales for the third-quarter, with $0.28-$0.30 in EPS. The Street appears to have slightly loftier expectations of $0.31 in EPS, and $156.1 million in revenue at the moment.

Now what: Align certainly has shareholders who are looking for double-digit growth potential chomping at the bit to jump onboard, but I'm not nearly as excited. The two factors that concern me about Align are consumer spending habits, and its valuation. Consumer discretionary income just isn't there right now, and I can foresee Align having a more difficult time gaining new customers if taxes continue to increase, or if the job market even has the slightest downdraft. Similarly, Align isn't exactly cheap, either, at 29 times forward earnings. Having worked in the dental industry many moons ago, I can tell you firsthand how fickle consumers can be when it comes to spending money on themselves in slow-growth economic environments. For now, I'd suggest keeping to the sidelines, and watching Align from a safe distance.

Fool contributor Sean Williams has no material interest in any companies mentioned in this article. You can follow him on CAPS under the screen name TMFUltraLong, track every pick he makes under the screen name TrackUltraLong, and check him out on Twitter, where he goes by the handle @TMFUltraLong.

Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.