Our Doctors

Founder of Cross Timbers ENT, Dr. James Leffingwell is a board-certified ENT specialist with more than 20 years of experience. After receiving his medical degree from the University of Cincinnati College of Medicine in Ohio, he moved to Texas to complete an internship in general surgery and a residency in otolaryngology at the University of Texas medical Brand at Galveston.

Dr. Leffingwell is board-certified in otolaryngology and completed post-graduate work in endoscopic sinus surgery. His career interests include endoscopic surgery, nasal reconstruction, and problems associated with sinus problems, including snoring and sleep disorders.

A native of Ohio, Leffingwell graduated with highest honors from Denison University in Granville, Ohio, in 1977.

Dr. Allis Cho graduated from the University of Texas at Austin in 2002 and attended medical school at UT Southwestern in Dallas. She then completed her otolaryngology residency at Louisiana State University Health Sciences Center in Shreveport. Although a native of Los Angeles, Dr. Cho decided to return to Texas to start her practice.

In addition to general otolaryngology, her specialty interests include otology, allergy and sinus disease, facial plastics, and laryngology. Dr. Cho is a member of the American Academy of Otolaryngology – Head & Neck Surgery and Texas Medical Association.

When not at work she enjoys reading, tennis, photography and traveling.

Luke Shellenberger, M.D., completed his otolaryngology-head and neck surgery residency at the University of Iowa, where he trained at the University of Iowa Hospitals and Clinics and the Children’s Hospital of Iowa. He received the 2005 Alfreda Van Wart Award for clinical resident research, as well as the 2003 Resident Teaching Award. Prior to surgical residency training, Dr. Shellenberger obtained his M.D. from Baylor College of Medicine, where he was an Alpha Omega Alpha honors graduate and was the Exceptional Graduate in Otolaryngology-Head and Neck Surgery for 2001.

A native of College Station, Dr. Shellenberger attended Baylor University, where he graduated Summa Cum Laude in 1997.

Dr. Shellenberger’s professional interests include pediatric and general otolaryngology, especially in the surgical treatment of hearing loss, head and neck and thyroid cancers, and facial reconstruction. He is active in several professional societies, including the American Academy of Otolaryngology, the Texas Medical Association, Board Certified in Sleep Medicine and the Tarrant County Medical Society. He has been invited to present papers at several national academy meetings and has published research articles in a number of national journals. His research interests include advances in the treatment of vocal cord paralysis and the management of pain after tonsillectomy.

Beyond his practice in Mansfield and Arlington, Dr. Shellenberger enjoys spending time with his two daughters, Caroline, and Audrey and his son, Alex.

Dr. Jonathan Wu is a Board Certified Otolaryngologist. He treats both pediatric and adult patients. He has interests in all aspects of Otolaryngology including chronic ear infections, hearing loss, nasal congestion, recurring sinus infections, tonsil/throat issues, and thyroid/parathyroid disorders.

He graduated from the University of Texas at Austin in 2004. He received his medical degree from UT Southwestern Medical School in Dallas in 2008. After completing his residency in Otolaryngology at West Virginia University, he returned to the DFW area to start his practice.

Dr. Wu is a member of the Tarrant County Medical Society, Texas Medical Association, and the American Academy of Otolaryngology – Head and Neck Surgery.

He enjoys spending his free time with his wife and daughter. They are expecting their second daughter in March.

Jennifer Paris, PA-C, joined Cross Timbers in 2016. She works alongside Dr. Shellenberger taking care of both pediatric and adult patients. She received her Bachelors of Science in Cell and Molecular Biology from Louisiana Tech University in 2006. She completed her Masters of Physician Assistant Studies in 2009 from The University of North Texas, Health Science Center in Fort Worth.

Prior to joining us she worked for a cancer group in Radiation Oncology and then in Urgent/Family Care. She enjoys taking care of the whole person and loves seeing her patients come back improved after appropriate treatment.

In her free time Jennifer enjoys spending time with her husband and three kids. They especially love cruising and learning about other cultures. She enjoys running and has run several half and full marathons and is always reading something.

Jason has worked in pediatric and adult ear, nose, and throat for 18 years. He received his Bachelor’s Degree in Psychology from the University of Houston in 1994. He completed his Bachelor’s Degree in Physician Assistant Studies from the University of Texas Medical Branch in Galveston in 2002. He also participated in numerous ENT research studies while working in San Antonio, Texas.

When Jason is not working, he enjoys spending time with his wife and children. They enjoy playing soccer, camping, and reading.

I’m a native Texan born and raised in Richardson. I earned a Masters degree in Speech and Hearing Science from Texas Tech University (Go Red Raiders!) and a Doctoral degree in Audiology from the University of Florida (Go Gators!). I’m a state licensed Audiologist and I’ve been providing hearing care for 30 years. I find the profession of Audiology rewarding because everyday I have the privilege of making a difference in the lives of others through the provision of hearing care, specifically in the areas of hearing loss prevention, detection, diagnosis, treatment and education.

I believe that a person’s connection to others and to the world is what matters most in life. Unfortunately, hearing loss weakens those connections. That’s why I strive, through the practice of Audiology, to help individuals connect, reconnect, and stay connected to the people and things that matter most to them.

My professional mission is to help you hear your very best so you may experience the joy of hearing wherever life takes you. If you want to prevent hearing loss, determine if you have a hearing loss, or want to improve your quality of life through better hearing, I welcome the opportunity to serve you.

When not providing hearing care, I enjoy spending time with my beloved wife and four children. A few of my favorite things include: early morning Bible quiet time and Sunday church service; watching and playing football and baseball; listening to music and building my record collection; reading and passing time in Barnes & Noble; watching classic movies; photography; bird watching; antique shopping; fellowship and coffee at Starbucks; cooking breakfast; and dining out.

Kristy Loftin-Moening, AuD, recently moved to Texas from Atlanta, Georgia. She is originally from Little Rock, Arkansas. She received her undergraduate degree from the University of Central Arkansas with a Bachelor’s Degree in Allied Health and obtained her Doctorate in Audiology from the University of Arkansas for Medical Sciences. During her doctoral coursework, she participated in a T35 Grant research opportunity with Vanderbilt University that involved a balance assessment of individuals with traumatic brain injury. She completed her clinical externship at Toledo Audiology with a focus on balance and vestibular disorders.

Dr. Loftin-Moening is licensed in the state of Texas and holds an American Speech-Language-Hearing Association Certificate of Clinical Competency in Audiology (ASHA). Dr. Loftin-Moening has worked in both private practice and ENT practices. She has a passion for balance and vestibular disorders with her previous background in physical therapy. Her interests include hearing loss and helping others improve communication for a better quality of life.

She enjoys spending time on the weekends with her husband, Sean. She enjoys attending concerts, sporting events and food festivals. She enjoys traveling, loves to cook and is an avid reader.

Margo Stewart, Au.D., earned her B.A. in Speech-Language Pathology/Audiology and her Doctorate of Audiology degrees from the University of North Texas. A native North Texan, Dr. Stewart’s clinical experience consists of advanced audiologic, vestibular and electrophysiologic assessment, as well as programming of traditional hearing aids, bone-anchored hearing aids and cochlear implants.

Dr. Stewart was born with hearing loss, which has led to a strong passion of helping individuals with hearing disorders improve their quality of life through hearing rehabilitation. In her spare time, Dr. Stewart enjoys inline speed skating, crafting, reading, cheering on the Dallas Cowboys, and spending time with her family and dog, Boomer.

Brenda Duran is the Practice Administrator for Cross Timbers ENT. She joined the practice in October 2017 and is responsible for overseeing the daily operations and management of each office. Since joining the practice, Brenda has focused her attention on organizational growth as well as evaluating the delivery of health care services to ensure physician, patient and staff satisfaction.

She has a B.B.A in Accounting from the University of Texas at Arlington. Brenda has over 18 years of experience in accounting of which 10 of those years are in the medical field. She has both a passion for numbers and helping people.

Brenda is a wife, mother, and a proud supporter of her family. She enjoys watching movies, traveling, and spending quality time with her husband and son.