About OASECT | Get To Know Our Orthodontic Team

At OASECT, orthodontics is about more than just straight teeth. It’s about giving our patients the confidence to shine. For over 65 years, we’ve served families across southeastern Connecticut with two convenient locations in Waterford and Norwich. Whether you’re exploring treatment for your child or yourself, our experienced team is here to make your orthodontic journey feel easy, rewarding, and fun.

With state-of-the-art technology, personalized treatment plans, and a warm, welcoming atmosphere, OASECT is proud to be the trusted orthodontic partner for generations of families. Our patients leave our practice with a boost of confidence that lasts a lifetime.

What Sets Us Apart

We blend advanced tools with a genuine, people-first approach to orthodontics. From Damon™ self-ligating braces and clear aligners to virtual monitoring and impression-free 3D scanning, we make your care efficient, modern, and comfortable.

Our team believes that visiting the orthodontist should be the best part of your day, and we strive to make that true for every patient.

Trusted Invisalign^® and Spark Aligner Providers

As a Platinum Invisalign® Provider and certified Spark aligner partner, OASECT stands out as a clear aligner leader in Connecticut. Our orthodontists tailor treatment to fit your lifestyle and goals—whether you’re considering clear aligners for yourself or your child.

Meet Our Orthodontists

Our orthodontists bring decades of experience, clinical expertise, and a true passion for creating smiles. They walk in our patients’ shoes as patients themselves, and that empathy drives every interaction.

Dr. James O’Leary

DMD

Dr. O’Leary brings a meticulous, patient-centered approach to every smile transformation. Known for his dedication to quality care and cutting-edge techniques, he has become a trusted name in orthodontics across the region.

Dr. Gregory Hack

DDS

Dr. Hack is committed to delivering confident smiles through personalized care and modern solutions. He has helped countless patients feel comfortable and confident throughout every phase of treatment.

PATIENT TESTIMONIALS

Hear from Our Patients

With hundreds of five-star reviews and countless stories of smile success, OASECT has built a reputation for excellence in orthodontic care and patient satisfaction.

    
 
 
       
   Evie Roeske 
 
 
 Trustindex verifies that the original source of the review is Google. amazing place with amazing people and amazing service and amazing results too!
  
 
      
   Donna Sylvia 
 
 
 Trustindex verifies that the original source of the review is Google. Great experience putting my braces on! Dr O’Leary and his assistant were awesome!
  
 
      
   Katie DeCaro 
 
 
 Trustindex verifies that the original source of the review is Google. Friendly and professional staff, wide availability for appointments, prompt care when needed for issues.
  
 
      
   Mark Bauer 
 
 
 Trustindex verifies that the original source of the review is Google. Always making the visit fun. Professional, kind, and focused on the realignment of the teeth.
...they are the best.
  
 
      
   Cello Souza 
 
 
 Trustindex verifies that the original source of the review is Google. Just started treatment, and it's been a quick, efficient, and informative process.  They do make sure everything is right the first time.  I'm pleased.
  
 
      
   Cathleen Cooper 
 
 
 Trustindex verifies that the original source of the review is Google. They were wonderful. When I had a problem with my retainer they went out of their way to make sure it was corrected! I would highly recommend them
  
 
      
   Eva Aller 
 
 
 Trustindex verifies that the original source of the review is Google. Love this place so much. Hope they meet all the best markers but they are all in such a good mood!
  
 
      
   Katie Messina 
 
 
 Trustindex verifies that the original source of the review is Google. Looking for the perfect orthodontic experience? Look no further! The staff at OASECT is the absolute BEST! They make you feel like family, bend over backwards to accommodate you and the results are incredible! My new smile is amazing!! Thank you so much Dr. Hack and crew!
  
 
      
   Nora Abdelghader 
 
 
 Trustindex verifies that the original source of the review is Google. The work was professional and the results were great.
I'm very satisfied with my new smile. I highly recommend Oasect.
  
 
      
   xriotingpacifist 
 
 
 Trustindex verifies that the original source of the review is Google. I could not recommend OASECT any more highly. I have a complex orthodontic situation but was praying to do aligners over metal braces. Dr O'Leary is a mouth magician, and was able to create an aligner treatment plan that can work for me. Even though I did need a single extraction to create room in my mouth, other orthodontists I had consulted with in the past were recommending 2 or more, so I am very happy with this outcome. Everyone that works in the office is just a peach and I am constantly smiling and laughing with everyone I meet there. I am 4 weeks into a year and a half of treatment, and everything is going fantastic so far- looking forward to the rest of the journey with OASECT!

Update 10/8/26: it has been a long road but I graduated out of aligners today - and I can't believe this is still my mouth, not only are my teeth now straight and pretty, but they are so much more functional for eating. I am just over the moon. I would strongly recommend OASECT and Dr O'Leary to anyone looking for ortho treatment in the area.

Visit Our Offices in Waterford and Norwich, CT

From your first consultation to your final smile reveal, our goal is to exceed your expectations at every step. We make orthodontics approachable, accessible, and genuinely enjoyable.

OASECT is here to help you smile brighter with orthodontics for all ages. Schedule your free consultation today to discover how orthodontics can change your life!