* Sees Q4 sales of $169.1-$173.1 mln vs est $164.3 mln
* Sales of Invisalign braces rise 16 pct in Q3
* Shares rise 15 pct
By Adithya Venkatesan
Oct 17 (Reuters) - Dental products maker Align Technology Inc's quarterly results beat expectations for the third time in a row due to strong sales of its invisible braces, sending its shares up 15 percent after the bell.
The company's Invisalign braces, which cost about $5,000 on average, have no metal brackets or wires and are easily removable unlike traditional braces.
Shipments of Invisalign braces rose about 16 percent in the third quarter, indicating that more doctors were showing confidence in the product.
Align also forecast fourth-quarter results well above analysts' estimates as it expands in its international markets and expects the sales momentum to continue.
The company expects to ship between 109,700 and 112,100 cases of its flagship braces in the fourth quarter, implying a growth of up to 19 percent.
Roth Capital Partners analyst Chirs Lewis said the company is usually conservative with its guidance and expects it to continue doing well in a market that has almost no rivals.
Align forecast fourth-quarter sales of $169.1 million to $173.1 million. Analysts on average had expected $164.3 million, according to Thomson Reuters I/B/E/S.
The company's third-quarter net income was $34.5 million, or 42 cents per share, compared with a net loss of $0.3 million, or breakeven on a per share basis, a year earlier.
Revenue rose about 21 percent to $164.5 million.
Analysts on average expected a profit of 30 cents per share on revenue of $158.6 million.
Align shares were trading at $52.95 in extended trading after closing at $45.93 on Thursday on the Nasdaq.