Greetings. Welcome to the Align Q4, 2021 Earnings Call. At this time, all participants are in a listen-only mode. A question-and-answer session will follow the formal presentation. If anyone should require operator assistance during the conference, please press star zero on your telephone keypad. Please note this conference is being recorded. I'll now turn the conference over to your host, Shirley Stacy with Align Technology. You may begin. Thank you. Good afternoon, and thank you for joining us. I'm Shirley Stacy, Vice President of Corporate Communications and Investor Relations. Joining me for today's call is Joe Hogan, President and CEO, and John Morici, CFO. We issued fourth quarter and full year 2021 financial results today via GlobeNewswire, which is available on our website at investor.aligntech.com. Today's conference call is being audio webcast and will be archived on our website for approximately one month. The telephone replay will be available today by approximately 5:30 P.M. Eastern time through 5:30 P.M. Eastern time on 16 February. To access the telephone replay, domestic callers should dial 877-660-6853 with conference number 13725950, followed by pound. International callers should dial 201-612-7415 with the same conference number. As a reminder, the information provided and discussed today will include forward-looking statements including statements about Align's future events and product outlook. These forward-looking statements are only predictions and involve risks and uncertainties that are described in more detail in our most recent periodic reports filed with the Securities and Exchange Commission, available on our website and at sec.gov. Actual results may vary significantly and Align expressly assumes no obligation to update any forward-looking statement. We have posted historical financial statements, including the corresponding reconciliations including our GAAP to non-GAAP reconciliation, if applicable, and our fourth quarter and full year 2021 conference call slides on our website under Quarterly Results. Please refer to these files for more detailed information. With that, I'll turn the call over to Align Technology's President and CEO, Joe Hogan. Joe. Thanks, Shirley. Good afternoon, and thanks for joining us. On our call today, I'll provide some highlights from the fourth quarter then briefly discuss the performance of our two operating segments, services, systems and clear aligners. John will provide more detail on our financial results and discuss our outlook. Following that, I'll come back, summarize a few key points and open the call to questions. Overall, I'm very pleased to report fourth quarter results and another record year, full year for Align. Net revenues of $4 billion and operating margin of 24.7% were both at the high end of our guidance for fiscal 2021. For systems and services, full year revenues increased 90.4% over the prior year to a record $705.5 million. For clear aligners, full year revenues increased 54.5% over the prior year to a record $3.2 billion. During 2021, we achieved several major installed base milestones, including our 12th millionth Invisalign patient, 68,000th iTero scanner sold and 47,000th exocad software license installed. Together, these elements are the foundation of the Align Digital Platform, proprietary combination of software systems and services designed to provide a seamless experience and workflow that integrates and connects all users, doctors, labs, patients and consumers. For Q4, revenues reflect continued strong growth and momentum from iTero scanner services revenues, particularly in North America, offset by lower than expected Invisalign clear aligner revenues. Through most of the fourth quarter, our clear aligner volumes were trending in line with our Q4 seasonality. However, the environment quickly changed in December with the rise of COVID-19 Omicron variant. We believe our Q4 clear aligner volumes were impacted by an increase in COVID-19 Omicron cases that caused customer lab shortages from a staff standpoint, practice closures or reduced hours and less patient traffic in December and that continued into Q1. This compounded an already slower seasonal period for many practices in which offices took time off in between the holidays. We estimate that our Q4 was negatively impacted by roughly three points of year-over-year revenue growth as a result of these factors. Where there are some similarities to what we experienced two years ago when COVID -19 first appeared, especially in China which currently has a zero-tolerance COVID policy, the environment today is different. There aren't broad government-mandated shutdowns, stay-at-home orders or extended quarantines but there is more consumer caution, self-imposed quarantines, higher inflation, less economic stimulus and supply chain shortages which makes it more difficult to predict when a recovery may occur. Nonetheless, Invisalign doctor submitters and case submissions are improving. We're working closely with our customers to support their needs and protect the health and safety of our employees. For Q4, systems and services revenues were up 61.3% year-over-year and up 21% sequentially, with strong revenue growth across all regions. Q4 results reflect the continued adoption of the iTero Element 5D Plus imaging system which we launched last year and that features innovative technology like near-infrared technology which aids in the detection and monitoring of interproximal caries lesions or cavities above the gingiva without harmful radiation. The iTero Element 5D Plus imaging system represents 75% of iTero volumes in Q4. In addition, over 50% of iTero scanner sales in Q4 were sold to first-time scanner buyers who are just beginning their Align Digital Platform journey. We also continue to see growth in our iTero scanner installed base with strong service revenues which historically have been a leading indicator of increased digital adoption among doctors. For Q4, clear aligner revenues were up 16.3% year-over-year with strong revenue growth across all regions and across the portfolio, including comprehensive and non-comprehensive products as well as Invisalign First, Invisalign Moderate, and Invisalign Go products. Our fourth quarter revenues also include non-case revenue for clinical training and education, doctor-prescribed retainer products and other dental consumables. During the quarter, we saw good performance from our retainer business overall, delivering strong revenue growth along with increased enthusiasm for the doctor subscription program pilot in North America. As we mentioned last quarter, our share of the retention market is significantly under-penetrated, even more so than our share of the orthodontic case starts. We have been developing a robust retainer strategy, including a separate marketing team, focused solely on driving adoption and increasing market share in the U.S. Our objective is to build brand awareness for Vivera retainers and drive engagement with doctors through clinical education and sales initiatives, while connecting consumers to doctors through demand creation programs and our concierge service. We've also recently implemented social media campaigns featuring the benefit of Vivera from the makers of Invisalign clear aligners. We believe that incremental investments will increase value for Invisalign practices and contribute to growth consistent with our long-term financial model target. Q4 non-case revenues also include accessories and consumables such as align, aligner cases, clam shells, cleaning crystals, Invisalign whitening pen, and other oral health products that are available on our e-commerce channel, including the Invisalign accessory store, Walmart.com, and Amazon.com. We view these ancillary products as a natural brand extension, enabling patient and doctor behaviour with the power of the Invisalign brand. Our full-year results reflect continued adoption and demand for both the Invisalign system and iTero systems and services and exocad CAD/CAM software as more doctors transform their practices to digital, and more consumers seek to transform their smiles through doctor-directed Invisalign treatment. Now let's turn to the specifics around our fourth quarter results, starting with the Americas. For the Americas region, full year 2021 Invisalign case volumes were up 57.6%. For Q4, Invisalign case volumes were up 11.5% year- over- year, reflecting growth across the region, especially in Latin America. On a sequential basis, Americas shipments were down 7.9% primarily reflecting the impact of Omicron previously described, as well as a seasonally slower teen season from Q3 to Q4. We also saw higher GP in adult case volume and continued momentum from our doctor subscription plan pilot. In Q4, we pledged a $1 million donation to the American Association of Orthodontists Foundation, the charitable arm of the American Association of Orthodontists in support of the science of orthodontics. We're also investing in educational grants programs to provide universities with greater access to all Align products for education and training purposes. Through these programs, our partnership with the Aligner Intensive Fellowship and the other in-person educational programs, we're investing in the orthodontic profession through the people who care for and treat patients directly. For systems and services, Q4 was a strong quarter for Americas, driven by continued adoption of iTero 5D Plus imaging system across customer channels, including our DSO partners. Services revenues continue to grow nicely, reflecting the growth of the iTero scanner installed base in North America. For the full year, international Invisalign case volume was up 51.6%. For our international business, Q4 Invisalign case volumes were up 10.7% year-over-year on tough comps compared to 2020. On a sequential basis, international shipments were up 1.7%. Notwithstanding the impact of the Omicron in December, we still saw strong growth in EMEA, offset somewhat by a seasonally slower period primarily in China. For the full year, EMEA Invisalign volume was up 69.5%. For EMEA, Q4 Invisalign case volumes were up 14.9% year-over-year with broad-based growth across all markets, led by Italy and Iberia, along with continued growth in our expansion markets in Turkey, Russia, CIS and Benelux. For Q4, year-over-year Invisalign case volume in EMEA was driven by increased submissions primarily from the orthodontist channel. On a sequential basis, despite the impact of Omicron, EMEA Invisalign case volume was up 13.6% primarily as a result of strong ortho channel performance, especially in the teen market. During Q4, we began commercial operations in Africa, with our initial focus on North Africa and then plan to enter Sub-Sahara Africa and South Africa this year, further broadening our expansion markets in EMEA. It's exciting opportunity for Align in this untapped and expanding totally addressable market. We're also making great progress on building our Europe manufacturing facility in Wrocław, Poland, which will be our third global aligner manufacturing operation. The Europe manufacturing facility is on track to go live during the first half of 2022, further increasing our ability to efficiently provide the Invisalign system to our valued doctor customers within the European region. For Q4, we saw strong scanner shipments during the quarter as more doctors in the EMEA region continue to digitize their practices. Through a full year, APAC Invisalign case volume was up 27.1%. For Q4, APAC Invisalign case volumes led by Japan, Korea, and India were up 3.4% year-over-year on tough comps despite continued COVID resurges, surgences, and lockdowns sporadically impacting various APAC countries, including China. We also saw strength in the GP dentist channel with increased Invisalign submitters and in the teen market with increased submissions from the orthodontic channel. On a sequential basis, APAC was down 15.4%, notwithstanding the impact of Omicron in December and Q4 seasonality in China. We had strong growth in Thailand, Southeast Asia, Taiwan. Overall, it was encouraging to see record numbers of shipments to those markets in APAC that were not as impacted by the most severe lockdowns. In Q4, systems and services in APAC saw the highest percentage of iTero scanners sold to new doctors. Today, we announced new Invisalign system innovations for the Align Digital Platform, a proprietary combination of software systems and services designed to provide a seamless experience and workflow that integrates and connects all users, doctors, labs, patients, and consumers. These new innovations include ClinCheck Live Update for 3D controls, the Invisalign Practice App, Invisalign Personalized Plan or IPP, and the Invisalign Smile Architect. We believe they will revolutionize digital treatment planning for orthodontics and restorative dentistry by providing doctors with greater flexibility, consistency of treatment preferences and real-time treatment planning access and modification capabilities. Each of these innovations is designed to enhance Invisalign treatment planning quality, efficiency, and scale, and contribute to better doctor-patient engagement and treatment outcomes. ClinCheck Live Update for 3D controls enables real-time ClinCheck treatment plan modifications that improve practice productivity significantly while also improving quality of treatment plans. Invisalign Practice App provides mobile integration with the Invisalign Doctor Site or IDS and enables doctors to manage their practices at their fingertips. Invisalign's Personalized Plan or IPP automatically applies a doctor's specific treatment preferences for comprehensive cases, enhancing efficiency and step-changing treatment planning consistency. Invisalign Smile Architect software is designed for GP dentists to create and visualize orthodontic restorative treatment plans for their patients using iTero digital scans and wide smile photos on the Invisalign Gold platform. The technical design assessment, go-to-market is scheduled for Q4, 2022. We know that every Invisalign-trained doctor has distinct preferences. Every patient is unique, and every treatment plan can vary depending on a variety of factors such as the type of malocclusion, patient age, and desired outcome. Because of that, doctors spend time planning, reviewing, and modifying their ClinCheck plans, and it multiplies with practice growth. IPP and ClinCheck Live Update for 3D controls are game-changing innovations that represent a step change in digital treatment planning to help doctors achieve more personalized ClinCheck treatment plans. By using 3D controls, doctors can see greater efficiency with changes reflected in real time. Invisalign Smile Architect combines facially driven and ortho-restorative treatment planning within the power of ClinCheck software, providing flexibility across treatment planning to address a variety of patient needs whether it may be orthodontic, restorative, or ortho-restorative combined. It allows doctors to share their vision with patients and use digital technology and tools to achieve the best quality clinical outcomes for their patients. It's through the convergence of advancements in digital technology, Align's unique capabilities and know-how, and data from millions of Invisalign patients that we're able to bring these new Invisalign innovations to our customers this year. The journey to deliver ClinCheck Live Update and Invisalign Personalized Plan has taken thousands of combined person years of development, testing, and learning and is only possible through the experience, data, and insights we have gained from over 12 million Invisalign cases. Across our innovations, we're also using a combination of AI and automation to reimagine what the treatment planning experience looks like for our doctors, doctor customers, and augmenting their expertise and experience to help them create and personalize and modify Invisalign treatment plans more efficiently and more consistently than ever before. What used to take several days can now be accomplished in just a few minutes, and it's a huge productivity win for doctors and their patients. Our consumer marketing is focused on educating consumers about the Invisalign system and driving that demand to Invisalign doctors' offices, ultimately capitalizing on the massive market opportunity to transform 500 million smiles. Consumer interest in the Invisalign brand remains high, and we are continuing to invest in building the brand in key markets and customer segments. This includes investments in social media as an effective channel to increase awareness and interest for Invisalign treatment. We're continuing to work closely with our media partners to reach consumers with the right creative and compelling campaigns, optimize our buys and test new approaches. In Q4, we continued to build on our successful Invis Is multimedia campaign across the Americas and EMEA and APAC, and drove awareness and interest in Invisalign treatment with adult, teen, and parent consumer segments. Globally, we delivered record impression volume with over 8 billion impressions representing 84% year-over-year growth and 21.7 million unique visitors to our website, a 127% increase year over year. In U.S., we amplified our campaigns across the top social media platforms such as TikTok, Snapchat, Instagram, and YouTube to increase awareness with teens about Invisalign treatment. Our campaigns continue to feature some of the largest teen influencers from our Invisalign Smile Squad, such as Collins, Devan Key, Charli D'Amelio, and Michael Le, each of whom share their personal experiences with Invisalign treatment and why they chose to transform their smiles with Invisalign aligners. Our consumer marketing programs also include connecting with teens within gaming, specifically on Twitch with a customized integration that was awarded the gold medal in the annual Internationalist Awards for innovation in digital marketing solutions. To continue growing our young adult business across the Americas and APAC, we build upon our successful Invisalign is a Powerful Thing campaign, which highlights the power of Invisalign treatment transformation for every young adult's self-confidence. Our integrated media plans across YouTube, Snapchat, Instagram, Facebook, and TikTok connected with young adults in the media channels they consume the most. In Brazil, we continue to amplify our Invisalign is a Powerful Thing campaign, featuring mega influencer, Taís Araújo, driving a 400% year-over-year increase in web traffic. In the EMEA region, we successfully expanded into new markets such as Italy and the Netherlands. To complement our integrated media plan with Google and YouTube, we also leveraged newer media channels such as TikTok and Snapchat, to drive engagement with consumers, resulting in more than a 170% year-over-year increase in unique visitors. We continue to expand our investment in consumer advertising across the APAC region, resulting in a 192% year-over-year increase in unique visitors and a 235% year-over-year increase in impressions. We continue to strengthen our investments in Australia, leveraging leading influencers featured in premium placements in TikTok and also YouTube. In Japan, we continue to see strong response from consumers, as evidenced by a 117% year-over-year increase in unique visitors. Lastly, we expanded our advertising investments in India and Taiwan which generated a strong consumer response. We saw a 1200% and 628% increase in impressions and a 470% and 116% increase in unique visitors to our websites in India and Taiwan, respectively. Adoption of our consumer and patient app, My Invisalign, continued to increase with 1.4 million downloads to date. Usage of our four digital tools continues to increase. For example, in addition to My Invisalign just mentioned, the Invisalign virtual appointment tool was used over 14,000 times and our insurance verification feature was used 24,000 times in Q4. Further, globally, we received more than 45,000 patient photos in our virtual care feature globally, which continues to provide us with rich data to leverage our AI capabilities and improve our services for doctors and patients. For our systems and services business, Q4 revenues grew 61.3% year-over-year, reflecting strong scanner shipments and services up 21% sequentially. This is the sixth consecutive quarter of sequential revenue growth for our systems and services business. As mentioned earlier, over 50% of scanner sales in Q4 went to first-time iTero scanner buyers. We're pleased to see doctors continue to go digital and invest in the Align Digital Platform. The iTero Element 5D Plus imaging system continued to gain traction across all regions, with the most recent launch in China during Q4. The series expands the portfolio of iTero Element scanners and imaging systems to include new solutions that more broadly serve the needs of doctors and patients in the dental market. A strong indicator of digital acceleration within the dental offices is the number of intraoral digital scans used for Invisalign case submissions. Total worldwide intraoral digital scans submitted to start an Invisalign case in Q4 increased to 85.4% from 79.3% in Q4 last year. International intraoral digital scans for Invisalign case submissions increased 80.8%, up from 73.7% in the same quarter last year. For the Americas, 89.1% of Invisalign cases were submitted using an intraoral digital scan compared to 84% in the same quarter last year. Cumulatively, over 50 million orthodontic scans and 10.3 million restorative scans have been performed with iTero scanners. With continued growth of the iTero scanner at 68,000 scanners sold worldwide as of Q4, approximately 30% is services revenue which includes recurring revenue subscriptions, CAD/CAM software, and ancillary products. We continue to make improvements in our scanner and imaging systems, making iTero systems and services an integral part of orthodontic and GP dentist workflow. For example, we streamlined the Invisalign case submission process with the iTero Element 5D imaging system's auto-upload functionality. Turning to exocad, for Q4 systems and services, revenues also include exocad CAD/CAM products and services. exocad's expertise in restorative dentistry, implantology, guided surgery, and smile design extends our digital dental solutions and broadens Align's digital platform towards a fully integrated interdisciplinary end-to-end workflows. Cumulatively, as of Q4, exocad now has over 47,000 software licenses worldwide. During the quarter, exocad announced the release of ChairsideCAD 3.0 Galway. It's the next generation of easy-to-use CAD software for single-visit dentistry. With this new release, exocad offers dentist design tools for a vast range of indications with a wide choice of integrated devices. Also, during the quarter, exocad announced the availability of ChairsideCAD 3.0 Galway software in the U.S. and Canada, where the software is now available in North America, EU, and other selected markets. exocad's ChairsideCAD is groundbreaking open-architecture CAD software for single-visit dentistry. It received the 2021 Cellerant Best of Class Technology Award from Cellerant Consulting Group during the quarter as well. This is the third consecutive year that ChairsideCAD has been recognized for this award. With that, I'll now turn this over to John. Thanks, Joe. Now for our Q4 financial results. Total revenues for the fourth quarter were $1.031 billion, up 1.5% from the prior quarter and up 23.6% from the corresponding quarter a year ago. For clear aligners, Q4 revenues of $815.3 million were down 2.7% sequentially due to lower Invisalign volumes, partially offset by slightly higher ASPs and up 16.3% year-over-year, reflecting Invisalign volume growth across all geographies and higher ASPs. In Q4, we shipped 631.1 thousand Invisalign cases, a decrease of 3.7% sequentially, an increase of 11.1% year-over-year. In addition, we shipped to 83.5 thousand Invisalign doctors worldwide, of which over 6,400 were to first-time customers. Q4 comprehensive volume increased 13.1% year-over-year and decreased 4.5% sequentially, and Q4 non-comprehensive volume increased 6.6% year-over-year and decreased 1.7% sequentially. Q4 adult patients increased 10.4% year-over-year and increased 0.1% sequentially. In Q4, teens or younger patients increased 13% year-over-year and decreased 11.8% sequentially. Clear aligner revenues were unfavorably impacted by foreign exchange of approximately $11.4 million or approximately 1.4% points sequentially. On a year-over-year basis, clear aligner revenues were unfavorably impacted by foreign exchange of approximately $1.5 million or approximately 0.2% points. For Q4, Invisalign comprehensive ASPs increased sequentially and year-over-year. On a sequential basis, Invisalign comprehensive ASPs reflect higher additional aligners, partially offset by unfavorable foreign exchange and higher discounts. On a year-over-year basis, comprehensive ASPs reflect higher additional aligners, partially offset by higher discounts. Q4 Invisalign non-comprehensive ASPs decreased sequentially and increased year-over-year. On a sequential basis, Invisalign non-comprehensive ASPs were unfavorably impacted by foreign exchange, partially offset by higher additional aligners. On a year-over-year basis, Invisalign non-comprehensive ASPs reflect higher additional aligners and product mix, partially offset by higher discounts. Clear aligner deferred revenues on the balance sheet increased $68.5 million or 6.9% sequentially and $332.9 million or 45.8% year-over-year, and will be recognized as the additional aligners are shipped. Our systems and services revenues for the fourth quarter were a record $215.8 million, up 21% sequentially and up 61.3% year-over-year. This marks the 6th consecutive quarter of sequential revenue growth. The increase sequentially can be attributed to increased scanner shipments and increased service revenues from our larger installed base. The increase year-over-year can be attributed to increased scanner shipments, increased service revenues from our larger installed base, as well as higher ASPs from the favorable mix shift towards higher priced iTero 5D scanners and imaging systems. Our systems and services deferred revenue on the balance sheet was up $42.6 million or 22.8% sequentially, and up $116.2 million or 102.6% year-over-year, primarily due to the increase in scanner sales and the deferral of services revenues which will be recognized rateably over the service period. Moving on to gross margin. Fourth quarter overall gross margin was 72.2%, down 2.1% points sequentially and down 0.9% points year-over-year. On a non-GAAP basis, excluding stock-based compensation expense and amortization of intangibles related to acquisitions, overall gross margin was 72.6% for the fourth quarter, down 2.1% points sequentially and down 0.9% points year-over-year. Overall gross margin was unfavorably impacted by approximately 0.1% points on a year-over-year basis and by approximately 0.4% points sequentially due to foreign exchange. Clear Aligner gross margin for the fourth quarter was 74.2%, down 2% points sequentially due to higher freight costs and additional aligners, along with lower primary shipments, partially offset by higher ASPs. Clear aligner gross margin was down 0.6% points year-over-year due to higher additional aligners and higher freight costs, partially offset by higher ASPs and improved manufacturing absorption due to higher volumes. Systems and services gross margin for the fourth quarter was 64.7%, down 0.9% points sequentially, primarily due to higher freight costs and increased component costs, partially offset by higher ASP from 5D Plus mix and higher service revenues. Systems and services gross margin was up 0.4% points year-over-year due to higher ASP from higher mix of iTero 5D Plus and higher service revenues, partially offset by higher freight costs and increased component costs. We are actively engaged in activities to mitigate supply disruptions by expanding supplier communications, modifying our purchase order coverage, and increasing inventory levels for key components. Q4 operating expenses were $523.7 million, up sequentially 6% and up 31.8% year-over-year. On a sequential basis, operating expenses were up by $29.7 million. Year-over-year operating expenses increased by $126.4 million, reflecting increased headcount and our continued investment in marketing, sales and R&D activities, and other investments commensurate with business growth. On a non-GAAP basis, excluding stock-based compensation and amortization of acquired intangibles related to certain acquisitions, operating expenses were $494.4 million, up sequentially 6.1% and up 32.8% year-over-year due to the reasons described earlier. Our fourth quarter operating income of $220.9 million resulted in an operating margin of 21.4%, down 4.3% points sequentially and down 4.1% points year-over-year. The sequential and year-over-year decreases in operating margin are primarily attributed to lower gross margin, investments in our go-to-market teams and technology, as well as unfavorable impact from foreign exchange. On a non-GAAP basis, which excludes stock-based compensation and amortization of intangibles related to certain acquisitions, operating margin for the fourth quarter was 24.7%, down four point one points sequentially and down 4.3% points year-over-year. Interest and other income and expense net for the fourth quarter was a loss of $0.9 million, down sequentially by $1.7 million and down year-over-year by $2.2 million. The GAAP tax rate for the fourth quarter was 13.2%, compared to 30.9% in the third quarter and 25.9% in the fourth quarter of the prior year. Our non-GAAP effective tax rate was 11.5% in the fourth quarter, compared to 22.2% in the third quarter and 14.5% in the fourth quarter of the prior year. The fourth quarter GAAP and non-GAAP effective tax rates reflected an out-of-period adjustment which reduced our tax rates by 7.3% and 6.3% respectively. Fourth quarter net income per diluted share was $2.40, up sequentially $0.12 and up $0.40 compared to the prior year. On a non-GAAP basis, net income per diluted share was $2.83 for the fourth quarter, down $0.04 sequentially and up $0.22 year-over-year. For the full year, net income per diluted share was $9.69, down $12.72 year-over-year due to the one-time tax benefit in 2020 of approximately $1.5 billion associated with our corporate structure reorganization completed during the first quarter of 2020. On a non-GAAP basis, net income per diluted share was $11.22 for the full year, up $5.97 year-over-year. Moving on to the balance sheet. As of December 31, 2021, cash equivalents, and short-term and long-term marketable securities were $1.3 billion, up sequentially $58.8 million and up $335.8 million year-over-year. Of our $1.3 billion balance, $582.9 million was held in the U.S. and $713.8 million was held by our international entities. Q4 accounts receivable balance was $897.2 million, up approximately 4.9% sequentially. Our overall days sales outstanding was 78 days, up approximately three days sequentially, and up approximately seven days as compared to Q4 last year. Cash flow from operations for the fourth quarter was $272.8 million. Capital expenditures for the fourth quarter were $109.1 million, primarily related to our continued investment in increasing aligner manufacturing capacity and facilities. Free cash flow, defined as cash flow from operations less capital expenditures, amounted to $163.8 million. In November 2021, we purchased $100 million of our common stock through an accelerated share repurchase which was approximately 0.2 million shares at an average price of $666.53 per share. We have approximately $725 million remaining available for repurchase under our 13 May 2021, $1 billion repurchase program. Before I move to our outlook, I would like to make a few comments on our full year 2021 results. In 2021, we shipped a record 2.5 million Invisalign cases, up 54.8% year-over-year. This reflects 51.6% volume growth from our international doctors and 57.6% volume growth from our Americas doctors. Total revenues were a record $4 billion, up 59.9% year-over-year, with clear aligner revenues, a record $3.2 billion, up 54.5% year-over-year. 2021 systems and services revenue were a record $705.5 million compared to $370.5 million in 2020 up 90.4% year-over-year. Full year 2021 GAAP operating income of $976.4 million was up 152.2% versus 2020, and operating margin at 24.7% versus 15.7% in 2020. On a non-GAAP basis, 2021 operating margin was 27.9% versus 20.3% in 2020. 2021 interest income and other income and expense, net of $36 million, included the SmileDirectClub arbitration award gain of $43.4 million. Excluding the SmileDirectClub arbitration award gain, interest in other income and expense was $7.4 million dollar expense on a non-GAAP basis. With regards to full year tax provision, our GAAP tax rate was 23.7%. The full-year tax rate on a non-GAAP basis was 18.5% compared to 17.6% for 2020. 2021 diluted EPS was $9.69. On a non-GAAP basis, 2021 diluted EPS was $11.22. Free cash flow was $771.4 million for 2021, up $264.2 million versus 2020. Overall, we are pleased with our Q4 results and another record year for Align. We delivered strong growth and profitability in line with our guidance despite disruptions late in the quarter from Omicron and other factors. Our Q4 revenue year-over-year growth was within our long-term model, despite disruptions impacting roughly 3% points of growth. We continue to see strong momentum and demand for our systems and services throughout Q4, with the majority of scanners being sold to first time buyers. We believe this is a good leading indicator of future Invisalign growth as our customers continue to invest in digital technology even during COVID. Let me turn to our outlook. We would normally expect sequentially higher Invisalign revenues and lower systems and services revenue, consistent with the typical Q1 seasonality. However, due to the continued impact of Omicron into Q1, we now expect our total Q1 revenue to be slightly down sequentially. We remain confident in our strategy, our huge underpenetrated market opportunity, our industry leadership, and our ability to execute. These factors have guided our approach throughout the pandemic, where we continue to invest in new technology, commercial expansion, and manufacturing capabilities to drive our growth. We plan to continue these investments in Q1 and therefore expect our Q1 operating margin to be less than 20%. In addition, during Q1 2022, we expect to repurchase up to $75 million of our common stock through either a combination of open market repurchases or an accelerated stock repurchase agreement. Turning to full year 2022, despite Omicron headwinds, we expect 2022 revenue growth to be in line with our long term model range of 20%-30%. Our 2022 guidance assumes no significant new COVID surges after the current wave, no meaningful practice disruptions nor material supply chain issues throughout the year. On a GAAP basis, we anticipate our 2022 operating margin to be around 24%. On a non-GAAP basis, we expect 2022 operating margin to be approximately 3% points higher than our GAAP operating margin after excluding stock-based compensation and intangible amortization from certain acquisitions. For 2022, we expect our investments in capital expenditures to exceed $350 million. Capital expenditures primarily relate to building construction and improvements, as well as additional manufacturing capacity to support our international expansion. This includes our planned investment in a clear aligner manufacturing facility in Wrocław, Poland, which is expected to begin serving doctors in 2022 as part of our strategy to bring operational facilities closer to customers. With that, I'll turn it back over to Joe for final comments. Joe? Thanks, John. Overall, despite the disruption from the Omicron in December, we delivered a record year with strong revenue growth and operating margin in line with our guidance for the full year on top of a record Q4 in 2020 a year ago. As we look back, I wanted to take a moment to recognize our accomplishments and thank our employees and our customers for another remarkable year. In the face of ongoing challenges related to COVID-19 and economic uncertainty, we've remained steadfast in our commitment to our employees, customers and the focused execution of our strategic initiatives. Our customers have remained confident in our ability to support them. Operating in this environment has not been easy but after two years of navigating uncharted waters, the Align team is more agile and resilient than ever. In 2021, we met our goals and achieved numerous milestones. Globally, we delivered across each of our strategic priorities, which are highlighted in our Q4, 2021 webcast slides. Our performance over the last year reaffirms the incredible size of our target market and demonstrates that our strategic investments in recent years are validated by the trust and faith our customers place in us. In 2022, we must continue to extend our leadership in digital orthodontics and restorative dentistry through relentless execution of our strategic initiatives, focusing on expanding our commercial, manufacturing, R&D, clinical, treatment planning, and manufacturing operations, and building our quality and regulatory muscle globally in existing and emerging markets. Reaching millions of consumers who want to transform their smiles using the most advanced clear aligner systems in the world through the right investments in advertising, PR, digital, social media, and influencer marketing to drive demand and conversion through Invisalign trained doctors. Invisalign ortho adoption and teen utilization of Invisalign treatment and training, and educating GP dentists on how the iTero Element family of intraoral scanners and imaging systems can propel today's dental practice into the future by enhancing patient experience and elevating clinical precision. On the benefits of digital dentistry with the Invisalign system trusted by more than 12 million people worldwide to transform smiles. We remain mindful of the ongoing uncertainty surrounding COVID-19 and the challenges that go with it. While there is still uncertainty, it has become increasingly clear over the last year with the first spread of the Delta variant and now Omicron, that COVID-19 may never fully go away and may be a virus that persists in one variant form or another and for the foreseeable future. Like other viruses, new or different vaccines will be needed and new therapies will be developed to minimize the impact and treat COVID-19 more effectively in our most vulnerable populations. The reality of living with COVID is one that governments, businesses and communities all over the world are beginning to acknowledge and move towards. At Align, we will do the same. In closing, I want to share some thoughts that I expressed to our employees recently. What we learn in life, both in business and our personal lives, is that we're not fully in control of our environment and destiny. This is a fact of life that we face every day. Not being in control does not mean that we can't make good choices regardless of the situation or challenges we all face. We must look forward, focused on the opportunities. Align has numerous growth drivers in a vastly under-penetrated market. While we continue to see some lasting impact and continued uncertainty due to COVID-19, we remain confident in both the enormous opportunity to lead the evolution of digital orthodontics and comprehensive dentistry. We never forget that digital orthodontics presents the fastest growing and largest market in the world of medical devices. We have the greatest clear aligner system, scanners, GP lab software in the world, and the broadest and deepest digital dental platform. We have the most recognized consumer brand and the largest direct sales force in the dental space, with over 4,000 salespeople supporting over 212,000 doctors and labs and their staff, who have incredible skills and dedication to their patients. We have an amazing team of employees committed to our purpose. It's a unique opportunity unlike anything I've ever seen in my career to both continue to grow Align and be part of positively changing millions of lives by transforming their smiles. Thank you for your time today. I look forward to speaking to you again as the year progresses. Now I'll turn the call over to the operator. Operator? Thank you. At this time, we will be conducting a question-and-answer session. If you would like to ask a question, please press star one on your telephone keypad. A confirmation tone will indicate your line is in the question queue. You may press star two if you would like to remove your question from the queue. For participants using speaker equipment, it may be necessary to pick up your handset before pressing the star keys. One moment please while we pull for a question. Our first question comes from the line of Nathan Rich with Goldman Sachs. Please proceed with your question. Thanks, good afternoon. Joe, thanks for all the details on the outlook. You called out the 300 basis point headwind from COVID in the quarter with the impact, I think, concentrated in December, so maybe a bit higher, you know, as we think about what the headwind was exiting the year. Could you maybe talk about how the impact in January is compared to what you experienced in December? Can you maybe elaborate on what you've seen in recent weeks? I'm just looking for a sense of maybe where January is trending and what you're assuming for the balance of the quarter to get you to the guidance that you gave for 1Q? Hi, Nathan. Hey, look, you know, we saw what we talked about in December. You know, it you know, we had a rapid decrease through COVID. What we've seen as we've gone into January is just a progressive improvement, you know? We feel good about that. We feel it's moving in the right way, and it's in direct correlation. We track it around the country with what's going on with Omicron in certain states and certain regions. Remember, this isn't just the United States. We've seen this all over the world. We see it in APAC, and we see it in Europe too, and we track it. Okay. Maybe just building on that at a high level, Joe, do you feel like the slowdown, I guess, is primarily a supply issue, just given the practice closures and lockdowns and staffing issues that you cited versus a demand issue? Because I think, you know, in your prepared remarks, you also mentioned some impacts from inflation and less stimulus. I'd just be curious to get your thoughts there. No. You know, we don't see this as a demand issue. I mean, we look at the market as we always have. You know, that's why we reasserted our 20%/30% growth rate for this year. This is not a demand equation issue or you call it a supply but I call it demand from a patient standpoint. We just see, you know, it's patients and doctors in the sense of cancellations, availability and all those things that COVID has you know has impacted around. We remain very confident. That's why you see us to continue to make investments, the things we announced today. W e feel really good about the business. We just have to, get through this first quarter and what we talked about, and we'll move on. We feel really good about it. Great. Thank you. Our next question comes from the line of Matt Miksic with Credit Suisse. Please proceed with your question. Hi, thanks so much for taking the question. Just maybe a follow-up on that question on planning assumptions around your Q1 comments and 2022 guidance. Maybe Joe, if you could just give a sense as to how, you know, you mentioned improvements in early January. Is this sluggish recovery, you know, wrapping up by the end of the quarter? Is Q2 the inflection to help you get to that 20%/30% growth that you mentioned? Just if I could also, on a similar topic, just the idea that somehow there is, you know, I think many folks on the call have heard this idea that somehow, you know, there was outsized growth during the pandemic, and we're sort of digesting that somehow now, which I know is one of the ways that folks look at Align and aligners and so on. If you could maybe just talk about your confidence that once we get through the staffing, that the demand that's in front of you, the growth drivers that you're laying in on top of your core markets, you know, that we're not looking to digest some sort of, you know, outsized growth during the pandemic year in 2022 but we're getting back to a growth market that's still highly under-penetrated. Sorry for the lengthy two-part question but would appreciate it. We understand the basis of your question, Matt. I mean, that's not a problem in that sense. Look, as I mentioned before, you know, we're really confident in the demand equation in the sense of clear aligners and Invisalign. You know, what we're experiencing right now is, you know, obviously a somewhat of a slowdown in our order demand pattern, you know, based on what we see through the virus that's going on around the world. As soon as that clears, and we see it clearing around the world, and as I mentioned, we see January improving over December, we're very confident in demand models that we've expressed for this business over the last several years. Thanks so much. Our next question comes from the line of Elizabeth Anderson with Evercore ISI. Please proceed with your question. Hi, guys. Thanks so much for the question. I guess on the first side, I think you obviously talked about some of the increased investments that you're making on marketing and also in sales capacity, et cetera. How do we think about the conversion efforts of those initiatives versus sort of prior, and sort of where do you sort of see that hitting in terms of as we're thinking about the pacing of the year? Hey, Elizabeth. Yeah, I mean, the pacing of the year, I mean, we continue to invest, as we mentioned, John mentioned, I mentioned it too in marketing. Where we invest, we understand the returns that we get no matter what the country is or, you know, what kind of media we use and, you know, in order to go after consumers. We've been very consistent in the sense of that investment and, you know, we move money around based on where we see the most opportunity. John, anything to add? We, you know, as we mentioned, we added some sales resources in Q4 to get ahead of, you know, sales territories and changes and so on. We saw that show up in Q4, but it really gives us the opportunity then to be able to grow as we get into this year. It's continued investments to drive the biggest return, and that's what we're continuing to do. Okay. It sounds like maybe no change in sort of the pacing that we've been seeing before. Maybe as a follow-up, I know you obviously highlighted that the total growth of the company would be in your 20%/30% range. Do you also see that the case growth on a year-over-year basis would be above 20% as you look out at this point? We'd expect them to be similar. When we talk about a 20%/30%, we're talking about revenue for the entire company but they would be similar from an outlook standpoint. Okay. Thank you. Thanks, Elizabeth. Our next question comes from the line of Jonathan Block with Stifel. Please proceed with your question. Hey, guys. Great. Hey, Joe. Hey, John. Good afternoon. Maybe just the first one, the operating margin compression year-over-year, the 24.7-ish gap that is to the 24. Maybe if you could talk to that. John, I was initially just gonna say it's a gross margin thing with scanners likely to grow much faster than case starts b ut to Elizabeth's question, it seems like you expect both to be within the guardrails of 20%/30%. Is it more a function of you guys just sort of, you know, call it running a little bit harder on the OpEx line to drive that case volume and why we would see that year-over-year, you know, operating margin compression? Again, I'm just referring gap to gap for apples to apples. I think, John, it's continued investments like we have with the story. It's continuing to invest that we have and being able to grow into this market. I think when we look at it overall, we're kind of pegging the gap rate to be at 24% for 2022, and we'll evaluate and update as we go forward. It's continuing to invest. We've got, you know, our Poland facility going live in 2022, and we have some of those moving parts that will impact our gross margin slightly as a result of that and that translates to operating margin. Those are the initiatives that we have, but nothing out of the ordinary that we've done in the past. Okay. Heads up, this next one's gonna be long, probably two parts. Maybe can you just get people comfortable with the fact that if you look at your 2Q, 3Q, 4Q, 2021 case files and the implied guidance for 1Q to get to 20%/30% case volumes for the year, you're gonna have to rip sequentially into Q3, Q4, Q of 2022. Maybe if you could talk to that. Then the other, you know, sort of third question, if you would, admittedly is, I'm confused on the 3% points. If 4Q was impacted by 3% points of growth, why don't you recapture, I don't know, 2% or 3% points of that in 1Q, 2022? You know, where are those cases going if they're not showing up in the, in the next possible quarter? Thanks, guys. I think I'll maybe start with the last part of your question, John. When you think of what's happened in the world with Omicron and the effects of that, it's affecting parts of the world at different phases. You see it even within the U.S. Northeast maybe gets hit with it first and starts to open up later. After that, maybe other parts of the country get impacted. It's not like it just happens and you immediately get it back. It comes down to when people are able to go to work in this case, at doctor's offices to be able to provide care. Then it comes down to when patients feel comfortable to be able to go back in. It's not an immediate effect in how we look at it. Think of, you know, in what we've learned from a COVID 1.0, the first time we saw this. We know that there's an impact and then there's a recovery period, and that's our best view of that recovery period. Hey, Jon. Fair enough. Hey, your other part about you have to rip the rest of the year, you know, we understand that. I mean, we've modelled it out. Remember our comparisons are a little better second half than they were first half when you look at, you know, what we did, you know, in 2021 in the first half of the year. You know, look, we wouldn't make that prediction if we didn't think it was feasible based on what we've seen and what we've modelled. Fair enough. Thanks, guys. Thank you. Thanks, John. Our next question comes from the line of Jeffrey Johnson with Robert W. Baird. Please proceed with your question. Jeff. Thanks. Good evening. Hey, guys. How are you? Hey, just a couple questions here from me. I guess one, you know, John, in 2021, you guys were talking about being within your LRP, but at the upper end of that. You know, do you wanna put any qualifiers on the LRP for 2022? It feels like kind of low end given where 1Q is starting. One, do you wanna put any qualifiers around where within that LRP you'd expect to be? Two, just go back to the last two questions again. I feel like I'm talking to my 10-year-old kid here, so apologies, but I'm gonna give you one more chance. Do you feel like case shipments can still grow within that LRP this year too, not just revenue because you've got, you know, some of the new products you're selling plus you've got faster iTero growth but case shipments also can be within that 20%/30% LRP? I just wanna make sure I'm hearing that correctly. Yeah, I can answer both of those, Jeff, in terms of, you know, the 20%/30%. We're reaffirming our 20%/30%, you know, similar to what we talked about at Investor Day, despite some of the things that we've talked about here, with Omicron and some of those COVID cases and so on. When we look at Invisalign case volume, we would expect to be, you know, in and about that range. Yeah. Nothing out of the ordinary from what we expect. We don't see, you know, our ASPs were very similar to what they were in the prior quarter. Provided that there's not, you know, FX or other things that we, you know, we're not projecting now, and if there's no change there, we would expect to be in that range as well. Fair enough. Then, Joe, maybe just update us on the competitive landscape. You know, we've seen a couple DSO contracts get announced here from others in the last few months and you know, maybe some talk over in China about some growing competition or slowing end markets and that. You know, where do you see your end markets across the globe from a competitive standpoint? Would just love to hear your update there. You know, Jeff, I think from a competitive standpoint, nothing's really changed. As we look out there, you can see the tech we just announced this week. We move on in the sense of our capabilities, what we can do. You know, my position's always been that, you know, competition isn't really affecting us from a price standpoint. I think you see that in what we're doing b ut, you know, they do serve to help to broaden the market and increase the market and increase the awareness. W e feel we're, you know, in this kind of competitive environment, we're doing well, and we lead in this sense. There's nothing as we go into 2022 that I'll reflect on that's changed competitively than what I've seen over the last three years. Understood. Thanks, guys. Yeah, thanks, Jeff. Thanks, Jeff. Our next question comes from the line of John Kreger with William Blair. Please proceed with your question. Hey, thanks very much. John John. Two quick ones for you. I think you said that the receivable DSOs were up about seven days year-over-year. Can you just expand on that? Were you providing some extra inducements to practices or anything to be concerned about there? Nothing to be concerned. You know, we're in a fortunate cash position as a company to be able to generate a lot of CFOA and free cash flow. In working with doctors to be able to, you know, give them more flexibility, sometimes we'll extend payments. We've actually seen historically low amount of past dues as we've gone through this time period in 2021. We feel very comfortable with that. It's just working with doctors to meet their cash flow needs, but nothing out of the ordinary. Okay, great. Thanks. One other one to clarify. I think you said that you expect the EBIT margin to be under 20% in the first quarter. Was that GAAP or non-GAAP? That, that's GAAP. That's GAAP. Okay. The 20% is GAAP-based. Thank you. Thanks, John. Thanks, John. Our next question comes from the line of Jason Bednar with Piper Sandler. Please proceed with your question. Hey, good afternoon. Thanks for taking the questions today. Hey there. You know, Joe, just real quick, can I ask whether you can confirm? You said January improved over December. I thought I heard you say that earlier in the call, or is it just that the January trend line showed improvement as the month unfolded? Sorry for just, you know, clarifying that, something nuanced like that here. Yeah, I think that to clarify, Jason, it's, you know, the month end showed improvement versus December. It was, you know, it's how COVID spreads across, whether it's, you know, one country or parts of countries and so on, and how it affects the staff and how it affects the patients then. As we exited, we were in a better trend line than we started the month with. Okay. Understood. Thanks for that. Maybe as a follow-up to an earlier question, really for Joe or John. I know you often talk about the internal investments you keep making in the business. You've talked about running a similar growth algorithm here in 2022 as you have in the past. We also have two different case examples here of the market with pre-COVID, and a lot of those resources were helping fund faster growth in your teen business. The last 18 months during the pandemic, adult demand has really taken off and grown faster than teens. I guess my question here is, as you went through your year-end planning, and you're obviously resourcing this business in another significant way here in 2022, how did you approach it for this year? Is it from a sales force ad marketing plan, and whatnot, is it or are you really with respect to how you're thinking about the adult and teen mix that you're expecting for this year? I mean, It's Joe, Jason. I mean, there's no big change in the sense of what we think the critical drivers are that we have to invest in to drive growth. You know, where we invest and how we invest is really important when you look at technology, when you look at consumer pieces, you know, however, you know, parts of those demand equations you wanna go to b ut remember, there's certain ratios that we always hold to in this business to set what we invest in, and we hold ourselves accountable for those ratios and that performance from a profitability standpoint b ut I can't overstate the importance of having a strong sales force. We talked about additional sales people that we're putting in place. Our consumer brand means a lot in the sense of our growth, and that's becoming more and more sophisticated in the sense of where we spend those dollars and how we spend those dollars. Leading in technology, you have to have technology in this business. That's why we were excited to really announce, you know, what we did today. We've been working on these programs for, you know, three years or more. These are game breakers in the sense of, you know, how you interface with a doctor and how a doctor interfaces with a patient. I would just add to that, Jason, you know, we're investing with that return on investment in mind. That's how we look at our long-term growth model. When we make investments, we have that in mind. In some countries, you're going deeper. You're adding more sales people to get closer to doctors and really help to drive that utilization. In other areas, where you don't have a direct sales force, you're just adding and just trying to get the breadth in there. Then we've been, you know, talking about a lot of the marketing activities and other things that we do to drive that awareness in some of those markets, and coupled with the research and development investments, some of it operations, again, to get closer to our customers, like in Poland. It's a multitude of investments, but we look at it with, how do we generate the best return? There's multiple different ways that we do it across these functions. All right. Very helpful. Thanks so much. Thank you. Thanks, Jason. Operator, we'll take one more call, please. Sure. The last question we'll have is from the line of Brandon Couillard with Jefferies. Please proceed with your question. Great. Thanks for squeezing me in. John, you've talked about freight costs for a few quarters now. Any chance, you know, you're planning a list price increase this year to help offset some of that? It's been a few years since you've taken list pricing. Yeah, it's a good question, and we are seeing freight, just like many companies have. We have a lot of plans in place to drive productivity. The operating team is very aware of our cost inputs and where we can drive productivity. Getting closer to our customers, like we talk in Poland, once we get there, that will be a freight savings, once we're operational there, and that'll help. We haven't, you know, we haven't really finalized any plans on a price increase. We'll evaluate as we go through, and the first people that we talk to would be our customers. You're right, we understand the price is important, but we're also very sensitive to our customers and what they've had to go through as we've been on this COVID journey. Nothing in the works now. Okay. Joe, on iTero, appreciate the detail as far as more than 50% of placements being new buyers. I would actually expect that to be normally the case, so what's the relevancy of that metric? Is that up a lot compared to historical levels? What percent of those placements are being used for Invisalign case submissions? You know, over the years, you know, Brandon, we've always seen that correlation, and we've communicated it to you in the sense of you sell more iTero scanners, you sell more Invisalign. That's, you know, obviously, you know, the front end of our digital system, and it works, you know, for us really well. We just have to decide the 50% because, you know, one, you saw we had a very strong fourth quarter for iTero. We always have strong fourth quarters, but this was exceptional in that sense. It was a good signal from the practices that we're dealing with, that this had to do with, you know, the day-to-day flow that you see from an Invisalign patient standpoint. It had nothing to do with their, you know, their enthusiasm in the sense of embracing the digital environment that we're talking about. To see the number of sales that we had, really in the last couple weeks of the quarter, it was just a good signal for us, and we wanted to share that with you, is that this market is embracing digital even when it's under pressure. We're performing really well in that area. As far as 50%, whatever, I don't know exactly what the historical percentages are in that way. We're, you know, obviously, what we're excited about is once those scanners are in place, it gives us a good foundation to sell Invisalign. Great. Thanks. Sure, Brandon. We have reached the end of our question and answer session, and I'll turn the call back over to Shirley Stacy for her closing remarks. Thank you. Thanks everyone for joining us today. We look forward to speaking to you at upcoming financial conferences and industry meetings. If you have any questions or follow up, please contact our investor relations team. Have a great day. Thank you. This concludes today's conference, and you may disconnect your lines at this time. Thank you for your participation.