Dr. Holly Ellis

Doctor of Dental Surgery and Owner

Dr. Ellis is a native of St. Louis, MO and now resides with her husband in Kirkwood, MO. She holds a Bachelor of Science in Cell and Molecular Biology from Missouri State University and a Doctor of Dental Surgery from the School of Dentistry at the University of Missouri, Kansas City. She married her husband, Justin, in 2005. They have a handsome son who was born in January 2012, a beautiful daughter who was born in June 2014 and their pup “Ace”. In her free time Dr. Ellis enjoys traveling, the outdoors, spending time with her family and friends, and playing “Wheel of Fortune” (she was an actual contestant on the show in 2003!).

Dr. Ellis is a member of the American Academy of Dental Sleep Medicine (AADSM), the only non-profit professional association dedicated exclusively to the practice of dental sleep medicine. Dr. Ellis helps treat snoring and obstructive sleep apnea with oral appliance therapy, an effective treatment that is covered by most insurance plans. AADSM membership provides Dr. Ellis with access to educational resources and practice management tools that help her better serve her patients by providing the highest quality of care in the treatment of snoring and obstructive sleep apnea. For more information about AADSM, visit our section dedicated to obstructive sleep apnea. 

Dr. Ellis dedicates herself to quality dental work by staying up to date on the latest dental technology and product information. She enjoys taking dental continuing education courses as well as staying active in local dental groups and study clubs. She has completed many courses from the Dawson Academy and Spear Education Center as well as many others in all disciplines in dentistry. Dr. Ellis completed a specialization in Dental Sleep Medicine at the Arthur A. Dugoni School of Dentistry at the University of the Pacific in San Francisco, California and is a Diplomate of the American Board of Dental Sleep Medicine.

Education and Certifications

Doctor of Dental Surgery
University of Missouri, Kansas City

Bachelor of Science, Cell & Molecular Biology
Missouri State University

Certificate in Dental Sleep Medicine
University of the Pacific, Arthur A. Dugoni School of Dentistry

Diplomate
American Board of Dental Sleep Medicine
 

Dr. Kelly O’Shaughnessy

Doctor of Dental Surgery

Dr. Kelly O’Shaughnessy was born and raised in St. Louis, MO. She grew up in South County, graduated from Oakville High School, and attended Southern Illinois University in Edwardsville for her undergraduate studies. Dr. O’Shaughnessy received her Doctorate of Dental Surgery degree from the University of Missouri Kansas City School of Dentistry and advanced her studies through an Advanced Education of General Dentistry program through NYU Langone in Juneau, AK.

Dr. O’Shaughnessy is a member of the American Dental Association, Missouri Dental Association, Greater St. Louis Dental Society, and the Academy of General Dentists. Her philosophy centers around the compassionate, comprehensive, and uncompromising care for every patient. Dr. O’Shaughnessy loves spending time with her family, rock climbing, hiking, and camping.

Education and Certifications

Doctor of Dental Surgery
University of Missouri, Kansas City

Bachelor of Science
Southern Illinois University, Edwardsville

Advanced Education in General Dentistry Program
New York University (NYU), Juneau, AK, Langone Dental Medicine

Dr. Kathryn Brennan

Doctor of Dental Surgery

Dr. Kathryn Brennan grew up in Saint Louis, Missouri, and received her undergraduate degree in Biological Sciences from DePaul University. She went on to receive her Doctor of Dental Surgery degree from Marquette University School of Dentistry, where she graduated with honors.

Dr. Brennan enjoys helping patients overcome their dental-related fear and anxiety. She believes in creating an environment that fosters effective communication and mutual respect, helping her patients feel valued and comfortable. Dr. Brennan understands the important role dental health plays in a patient’s overall health and well-being, and is passionate about delivering comprehensive and individualized care.

Dr. Brennan is a member of the American Dental Association, the Missouri Dental Association, the Greater St. Louis Dental Society, and the Missouri Valley Study Club. She volunteers annually with Give Kids A Smile and Mission of Mercy to provide dental care to children and adults in need. In her free time, Dr. Brennan enjoys watching Cardinals baseball with her husband, completing home improvement projects, and spending time with her rescue dog.

Education and Certificates

Doctor of Dental Surgery
Marquette University

Bachelor of Science, Biological Sciences
DePaul University

Dr. Krista Cayo

Doctor of Medicine in Dentistry

Dr. Krista Cayo has been practicing dentistry in St. Louis since 2010. A graduate of the Southern Illinois University School of Dental Medicine, Dr. Cayo also earned an additional certificate in Advanced Education in General Dentistry in 2011. Dr. Cayo is originally from Illinois and moved to the St. Louis area to begin her dental career.

One of her most valued aspects of dentistry is building relationships to ensure trust and genuine care for her patient’s dental health, and she does this by actively listening to patients’ needs and concerns. She strives to provide a calm and compassionate atmosphere and treats patients of all ages and backgrounds.

In her spare time, she enjoys biking, pickleball, and spending quality time traveling and cooking with her husband Luis, and two school-aged children, Sebastian and Camila.

Education and Certificates

Doctor of Medicine in Dentistry
Southern Illinois University, Edwardsville

Bachelor of Science
Southern Illinois University, Edwardsville

Advanced Education in General Dentistry
Southern Illinois University, Edwardsville

Denise

Registered Dental Hygienist

Denise graduated from St. Louis Community College at Forest Park in 1984. She has been working with patients at Ellis Dental since 1999. Denise is absolutely passionate about her profession and her patients, especially educating them how their oral & medical health are connected. She has created many friendships with her long time patients and is honored to be their hygienist.

Denise has 4 grown sons, a chef and 3 U.S. Marines. She is so proud of them as they go forth on their personal journey of life. When Denise is not working, she enjoys her home, kayaking, camping & hiking the great outdoors, and her newest fun venture is learning the Ukelele.

Education

Associate in Applied Science, Dental Hygiene
St. Louis Community College, Forest Park

Jennifer

Registered Dental Hygienist

Jen graduated from St. Louis Community College at Forest Park in 2013. She is certified in infiltration, block anesthesia and nitrous oxide.

When she is not working she enjoys spending time with her family and attending her nieces sporting events. Jen loves running, cycling, and in the summer months spending weekends at the lake with friends and family.

Education

Associate in Applied Science, Dental Hygiene
St. Louis Community College, Forest Park

Sandy

Registered Dental Hygienist

Sandy is a native of St. Louis, MO and graduated from St. Louis Community College at Forest Park in 1995. She is licensed in infiltration anesthesia, nitrous oxide administration and certified in laser and oral conscious sedation dentistry. Sandy is excited and honored to be a part of the Ellis Dental Team. Being able to work together with her patients to achieve their goals for overall health and a healthy smile is her favorite part of her job. She’s at her happiest when helping others whether it be in the office or in her day to day endeavors.

Sandy met her husband in 1996 when he sat in her chair. They are blessed with one daughter who is in the high school AFJROTC program and is excited to see where her dreams will soar. She enjoys spending time with her family and pets, cycling, DIY projects, movies, gardening, the great outdoors, music and going to concerts.

Education

Associate in Applied Science, Dental Hygiene
St. Louis Community College, Forest Park

Medina

Registered Dental Hygienist

Medina began her journey at Ellis Dental in 2018 as a sterilization and hygiene assistant. After graduating from St. Louis Community College at Forest Park in 2022, she returned as a dental hygienist. She is certified in infiltration, block anesthesia, and nitrous oxide, and loves expanding her skills by learning from the talented hygienists she works with.

Outside of the office, Medina enjoys hiking and walking with her fiancé and their German Shepherd, Bella. She also spends her free time outdoors gardening, biking, and riding four-wheelers to catch the best views of the sunset. Ellis Dental truly feels like home.

Education

Associate in Applied Science, Dental Hygiene
St. Louis Community College, Forest Park

Vicki

Certified Dental Assistant

Vicki graduated from Missouri College and has been applying her talent and expertise in the dental field since 2002.

She enjoys singing, reading, listening to music and spending time with her family.

Education

Certified Dental Assistant
Missouri College

Madison

Certified Dental Assistant

Born and raised in Wentzville, Mo, Madison is the youngest of four and has eight nieces and nephews. She lived in Virginia, near Washington D.C., for 4 years and moved back home in the summer of 2022. She spent 3 years as a Kindergarten teacher before realizing she felt more fulfilled in the dental field. She and her husband, Hunter, are thrilled to be back, closer to their families. Madison has a 4-year-old husky named Echo who is her fur-baby. In her free time, Madison enjoys watching Netflix documentaries and trashy reality shows, going to the gym, and watching Cardinals baseball.

Education

Bachelor of Science, Elementary Education
Southeast Missouri State University

Daniela

Certified Dental Assistant

Daniela attended St. Charles Community College from 2019-2020 before graduating from Midwest Institute of Fenton in 2021. Daniela is excited to be able to work with a group of wonderful people who are willing to teach her different techniques in the dental field. Being able to make a patient smile and overcome any fear in the dental chair is Daniela’s goal.

When not in the office, Daniela is almost always spending time with her family and enjoying those precious moments.

Education

Certified Dental Assistant
Midwest Institute

Bailey

Sleep Administrator

Bailey serves as a Sleep Coordinator at Ellis Sleep Center, where she guides patients through the diagnosis and treatment of obstructive sleep apnea using advanced, patient-centered care. Based in St. Louis, MO, she provides education on the symptoms of sleep apnea, the benefits of oral appliance therapy, and how to complete a sleep study, even for those navigating complex insurance questions.

With personal experience as a sleep apnea patient, Bailey brings deep empathy and understanding to every interaction. Her firsthand success with dental sleep medicine allows her to build strong connections with patients and help them overcome the same challenges she once faced.

Bailey’s greatest reward is hearing from patients who finally sleep through the night after years of struggling. Her goal is to empower individuals to take control of their health, reduce the risks of heart disease and fatigue, and enjoy a higher quality of life through proven sleep apnea solutions.

When she’s not at the Ellis Sleep Center, Bailey enjoys running, spending time with her family, and caring for her beloved cats.

Education

Bachelor of Science, Criminology/Criminal Justice
Missouri State University

Megan

Registered Dental Hygienist & Sleep Advocate

Megan joined Ellis Sleep Center in 2024 as a dedicated Sleep Advocate after a decade in clinical dental hygiene. A graduate of the University of Missouri – Kansas City, she now uses her expertise to help patients in St. Louis better understand their options for sleep apnea treatment, including oral appliance therapy, a proven alternative to CPAP for those with obstructive sleep apnea.

What sets Megan apart is her personal journey with sleep apnea. Her own diagnosis and treatment changed her life, fueling her passion for helping others rediscover restful, restorative sleep. She walks patients through the process of obtaining sleep studies, explains the benefits of oral appliances, and provides ongoing support every step of the way.

Outside of the office, Megan enjoys time with her two children, Lenni and Franni. She loves reading, cooking, exploring the outdoors, and savoring a good cup of coffee.

Education

Bachelor of Science, Dental Hygiene
University of Missouri, Kansas City

Jamie

Scheduling Coordinator

As the Scheduling Coordinator at Ellis Sleep Center in St. Louis, MO, Jamie plays a vital role in helping patients access the care they need to manage obstructive sleep apnea (OSA) and other sleep-related conditions. With a focus on compassionate, personalized service, she coordinates evaluations, sleep studies, and follow-up appointments, ensuring that every patient receives timely and efficient care.

Jamie is passionate about improving lives through dental sleep medicine, having seen firsthand how untreated sleep apnea can lead to serious issues like chronic fatigue, poor concentration, and cardiovascular problems. Whether you're scheduling your first sleep apnea consultation or navigating the next steps in your treatment journey, Jamie is here to make the process smooth and stress-free.

Associate in Applied Science, Dental Hygiene
St. Louis Community College, Forest Park

Danette

New Patient Coordinator

Danette graduated from Missouri College in 2011 as a Certified Dental Assistant, obtaining Dean's List honors. Shortly after graduation she earned her Expanded Functions in Restorative & Fixed & Removable Prosthodontics.

Danette loves bragging about her son, Brayden, and spending time with him. When the weather is nice out, Danette loves bicycling and traveling. On the weekends you can find her with her wonderful boyfriend, Steve, trying new places to have brunch!

Education

Certified Dental Assistant
Missouri College

Donna

Receptionist

Donna has worked in the dental field for over 20 years, both as a dental assistant and in various administrative roles within the office. Donna excels at helping patients schedule their treatments, particularly with their busy schedules.

When Donna is not in the office, she enjoys reading and following the St. Louis Blues and Cardinals. She is one of six siblings and she has a twin sister!

Education

Certified Dental Assistant
Bryan University

Eileen

Receptionist

Eileen was born and raised in Galloway, New Jersey. She attended Absegami High School and later studied Business at AIU. Although her most recent position was with a pulmonary and sleep practice, Eileen brings over 10 years of dental experience to the Ellis Dental team. She truly enjoys helping patients stay on track with their appointments and dental care, and she feels grateful to be part of such a welcoming and supportive office.

Eileen is a proud mom of three young adults. Gianna lives in Florida and is completing her cosmetology program. Angel, in New Jersey, is a licensed practical nurse and is also training to become an electrician. Her youngest, Isabella, has completed her business studies and currently works as a barista.

Eileen now lives in Missouri with her partner, Stephon, both originally from New Jersey. When she’s not working, she enjoys camping and lake time with friends, reading a good book, and traveling whenever she can.

Education

Associate of Arts, Business Administration
American InterContinental University