Dear patient and parents, we will start calling patients to schedule appointments on Monday May 18.


Welcome To Liu Orthodontics!




Beautiful , Confident Smile

Dr. Terry R. Wallen, DDS, MS


  • Don’t like the metal braces but still want a beautiful smile? Then clear aligners might be a good fit for you.


Clear aligners provide a great alternative to straight your teeth compared to traditional braces. Clear aligners are much less noticeable, especially good for adults who don’t want to metal braces impacting their appearance. They are almost invisible and easy to remove. This can go a long way in helping to improve your confidence as your smile improves. You can remove the aligners to eat, brush and floss your teeth reducing the risk of cavities. Did we forget to mention there are no food restrictions? For young athletics, the aligners allow less discomfort like poking wires or the possibility of a loose bracket when playing contact sports.


Clean align therapy uses a seriesThey are removable. You can take them out to eat with no food restrictions. You can take them out to brush and floss your teeth with a lower risk of getting cavities. Also, there is no poky wire or loose brackets with clear aligners. For young athletics, there is no problem of robbing cheeks of braces when playing contact sports.


Clean aligners therapy uses a series of clear, removable, and comfortable aligners to move your teeth. Each aligner makes gradual adjustments to correct your teeth. They use gentle pressure to gradually shift your teeth where they need to go.

Drs. Liu and Wallen are certified providers of both Invisalign and Suresmile clear aligner system. At Liu Orthodontics, we will scan your teeth using a 3D intraoral scanner and use 3D computing software to mimic tooth movement to design sequential aligners just for you. However, just like braces staying on your teeth all the time, you need to wear your aligners at least 22 hours a day, except brushing and eating. Otherwise, aligners simply will not move the teeth as well as braces. Patient compliance is the number one determining factor of the success of clean aligner therapy.


Clear aligners are excellent in straitening your teeth. However, sometimes there is a limitation of treating more complex cases. Sometimes, a hybrid approach with clear aligners and traditional braces or other appliances can be used for the best treatment outcome possible.

If you would like to know if clear aligners are good for you, please schedule a complimentary consultation with Dr. Liu or Dr. Wallen. We would love to discuss your needs and design a treatment plan specifically designed for you.


Once finishing phase I treatment, braces will be removed. Patients usually wear retainers until all the permanent teeth erupt. Tooth eruption will be monitored. Dr. Liu or Dr. Wallen will see them usually every 6 months and supervise retainers wear or determine if removal of certain primary (baby) teeth is necessary during this break period.


The second phase is initiated after all permanent teeth have erupted for an average of 12-24 months. In the second phase, tooth position will be finalized and detailing using braces or clear aligners. A harmony, healthy, beautiful smile is created with balance of facial structures.


Retainers must be worn after this phase to ensure you retain your beautiful smile. At Liu Orthodontics, we usually use upper clear retainer and lower fixed retainer with or without clear retainer. It is very important for you to wear your retainers as instructed. Otherwise, teeth will move back where they were. You can click link to learn how retainers work.

Education and professional background

My passion in orthodontics has driven me to receiving many years of education and pursing professional development.  Being born and raised in Taiwan, I attended Taipei Medical University, where I earned my DDS and Master’s degree of Orthodontics in 1999 and 2003. I received my PhD degree from Baylor College of Dentistry, Dallas, Texas in 2008. Shortly before graduation, I was appointed as Assistant Professor of Orthodontics in the Indiana University School of Dentistry. Meanwhile, I completed my second Master’s degree in Dentistry and Orthodontic certificate from the Indiana University School of Dentistry.  Later in 2015, I was promoted to tenured Associated Professor and became a certified orthodontist by American Board of Orthodontists.

I love practicing, researching, and teaching orthodontics. There are more 40 scientific papers I published in American Journal of Orthodontics and Dentofacial Orthopedics, European Journal of Orthodontics, Angle orthodontists, and Bone.  I am also a coauthor of “Basic and Applied Bone Biology”.  In 2010, I was honored the Beni Solow Award because my article was selected the best paper of European Journal of Orthodontics. After serving as Director of Orthodontic Fellowship Program for 3 years, my enthusiasm of teaching was well recognized and honored the Outstanding Faculty Award in 2013.

Outside the office

  • Outside my professional life, I am also a loving husband and father of 2 boys. We love to travel and explore the outdoors. We enjoy clamming, camping, and hiking in state parks. My older son, Ryan, plays soccer all year round. You might run into us in the soccer fields of Washington Cup. My little boy, Jaylen, loves art. You might see us doing some craft projects together at school festival nights.

Professional Honor and Awards

Resident’s Choice- Outstanding Orthodontic Faculty Award

Indiana University School of Dentistry 2013


Beni Solow Award

European Orthodontic Society 2011


Albert P. Westfall Memorial Teaching Fellowship Award

American Association of Orthodontists 2010


Orthodontic Faculty Development Award American

Association of Orthodontists Foundation 2010


Faculty First Award

American Association of Orthodontists 2009


Outstanding Research Award

Congress of Taiwan Association of Orthodontics 2003


Best Graduate Resident

Taipei Medical University 2003

Dr. Terry R. Wallen, DDS, MS

Dr. Terry Wallen, the founder of our office, is one of the pioneer orthodontists in the northwest. He established our practice in 1974 and has treated more than ten thousand patients.

Academics and Accomplishments

  • Terry Wallen completed undergraduate studies at Seattle University.
  • He received his dental education at the University of Washington.
  • He received numerous awards for academic and clinical excellence.
  • Dr. Wallen was inducted into the Omicron Kappa Upsilon honor fraternity which is reserved for those graduating in the top 10% of each class.
  • At the University of Kentucky, he received his specialty training in orthodontics.


  • Wallen was a part-time Clinical Professor of Orthodontics at the University of Washington
  • A certified member of the American Board of Orthodontists.
  • A recipient of the Edward Hatton Award from the International Association of Dental Research
  • An Internationally-known lecturer and widely published author in the specialty of orthodontics
  • An editorial consultant to an orthodontic journal

118 SW 330th St #200, Federal Way, WA 98023

TEL:(253)838 - 0765

FAX:(253)838 - 3416

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