Our Doctors & Staff

The Baltimore Uptown Dentist Team

  • Dr. M. Alexander Barton D.M.D.

    A Baltimore native, Dr. Alex Barton D.M.D. grew up in the Towson area and attended the Saint Paul's Schools. Upon graduation from St. Paul's Upper School, Dr. Barton attended the George Washington University in Washington, D.C., where he obtained a B.S. in Public Health in 2015. 

    Prior to beginning dental school at the University of New England, Dr.Barton worked as a lab technician in the Neurology Department at the Johns Hopkins University School of Medicine doing mass spectrometry. During his time in dental school Dr. Barton spent many hours volunteering at the PrebleStreet Soup Kitchen and helped create and manage a student-run study club. Additionally, he pursued several externships in Oral Surgery along the east coast and spent three months on rotation at a federally Qualified Health Center in Augusta, Maine. 

    Dr. Barton is a member in good standing in the American Dental Association, the Maryland State Dental Association, the Baltimore County Dental Association, as well as the American Academy of Facial Aesthetics through which he completed an intensive certification program to provide various cosmetic procedures. Dr. Barton enjoys fishing, skiing, and playing squash. When not on the go he is most often spending time with his wife, Kells, and their English Bulldog, Winnie.

  • K. Michael Murphy, DDS, MS
  • Dr. med. dent. Alexandra Welzel, DDS, FAGD

    Dr. Alexandra Welzel, a native of Germany, has been providing exceptional dental care for over 30 years.  Her passion lies in listening to each individual, and working with them to find the ideal solution in a caring and nurturing environment.   She can help you find your best smile using cosmetic options including straightening teeth with clear aligners, teeth whitening, veneers, crowns, bridges, bonding and more.  

    She is a member of the American Dental Association (ADA), the Maryland Dental Association , the Baltimore City Dental Society and the Academy of General Dentistry (AGD). Dr. Welzel is the AGD recipient of the prestigious 'Fellow of Academy of General Dentistry' award, in recognition of a commitment to oral care that goes above and beyond traditional education and licensing requirements. She enjoys learning about the latest advances in dentistry through continuing education and collaborating with her peers in frequent case study sessions.     

    In her spare time, Dr. Welzel enjoys outdoor activities, from cycling and swimming to designing her own garden.

    • Graduated from a Dental School, RWTH Aachen,  Germany in 1992.
    • Completed research and Doctoral Thesis, Magna Cum Laude, at the Department of Oral-Maxillofacial Surgery at the RWTH Aachen, Germany in 1994, where she was awarded Doctor Of Medical Dentistry (Dr. med. dent.).
    • Private practice in Germany until 1996.
    • Completed 3 years of residency in Advanced General Dentistry with enrollment in the MSOB program at the University of Maryland Baltimore College of Dental Surgery and received her American Dental License in 1998.
    • Is an active member of dental organizations including the American Dental Association and the Academy of General Dentistry.


  • Tamela Wittman
    Front Desk Administrator

    I have been blessed with an amazing career for over 26 years in the dental field. I started as a licensed dental assistant/radiographer and transformed over 15 years ago into business management and marketing which is where my college background of Business Management in Health Care Utilization is. I am a cross trained medical biller-with a strong concentration in Sleep Apnea. My educational and professional backgrounds have given me a world of knowledge plus such a passionate life career! 

    I am super blessed to be a mother to my son and there is even a wedding in my near future! I love to cycle, hike and ski. I am a volunteer reading and writing tutor and a mentor with My Sister's Circle-Baltimore City Mentoring Program.

  • Katherine Niebel
    Front Desk

    I've been in the dental field since 2011. First starting as a dental assistant and later increasing in knowledge and experience to confidently obtain a position as a front desk personnel. My favorite parts of dentistry has always been oral surgery and reconstructive surgery. I enjoy building a rapport with patients through dental education.

    I have 2 lovely daughters and I'm happy to announce we are expecting a baby brother in April 2023.

    I enjoy spending time with family and traveling.


  • Roxanne Triplett
    Front Desk

    I have been in the dental field since 2002. I started as an Oral Surgery Assistant and progressed to front desk.  I  enjoy helping others and working as a team. When I am not at work I enjoy spending time with family and 3 pitties and 2 kitties. 


  • Sherri Feldman

    Sherri was born in Baltimore and graduated from CCB and UMAB with a BS degree in Dental Hygiene. She has been practicing dental hygiene for 34yrs and has been with Dr Murphy for 20 years. She is married and has two beautiful young adult daughters aged 20 and 21. In her spare time, Sherri likes to swim, bike, run and practice yoga. She has been participating in triathlons from sprint distance to full distance Ironman's for the last 13 years. You can blame Dr Murphy for her love of triathlon! Sherri has been participating in triatholons since 2006 and has been a certified integrative health coach since May 2021.

  • Sandy Sheffler

    Many of you know me since I have been working with Dr. Murphy and Dr. Welzel since 2004. My career as a dental hygienist started in 1973. It has been my passion to help people achieve optimum health both dentally and physically. Along the way I have forged amazing relationship with both patients and co-workers. 

    I am now a grandmother of a little boy name Hank, born in 2021. I will be having another grandchild, a girl this time. Her name will be Avery and she is due March 2023. Having turned 70 and a very long career of 50 years as a hygienist I plan to retire at the end of December 2023. 

    I have many, many interests and hobbies that I will continue to enjoy after my retirement: babysitting, bridge, sewing, knitting, many other crafts, cooking and baking. I love to do home improvements, and gardening as well. 

    Love, Sandy

Dental Assistants

  • Tonia
    Dental Assistant

    Bio coming soon!

  • Reanna
    Dental Assistant

    I have been in the great world of dentistry for 27 years, starting off as a lab technician. In 1999, I graduated from Medix as a Dental Assistant and began working in my first office in Baltimore. I am still assisting and doing lab work helping to give patients their smiles back. 

    I am also a very proud mom of two amazing sons. We play lots of sports. I enjoy going to the movies and spending time with family and friends. 

  • Heather
    Dental Assistant

    Bio coming soon!

  • Kenya
    Dental Assistant

    I've been an assistant since 2005, my certifications include CPR, Radiology, and expanded functions. It has always been a joy to help people to obtain a new smile and feel good. Since being apart of this dental family I have learned so much with the state of the art technology and continuing education classes. 

    When away from the office much of my time is dedicated to expanding my social media based small business 'Randoms by KENYA' 

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9:00 am-6:00 pm


8:00 am-5:00 pm


8:00 am-3:00 pm


9:00 am-7:00 pm


8:00 am-3:00 pm





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