Our Approach

Dentistry Done Differently

Our Mission at Twenty28 Dentistry

At our office, we believe that dentistry is about more than just what happens in the chair. Our goal is to provide a stellar dental experience to every patient who walks through the door and we achieve this through open communication, quality dental work and a down-to-earth approach. Whether it has been six months or six years since your last dental appointment, you’ll quickly feel at home with our judgment-free care. Call today to schedule a visit and see the difference at Twenty28 Dentistry!

Doctor Chengs Family

Get to Know


Dr. Craig knew that he wanted to be a dentist from a young age. When he was a kid, he always looked up to his family dentist who took an upbeat and energetic approach to every visit and never made dental care feel intimidating. Dr. Craig was always intrigued by the fun gadgets used during regular hygiene appointments, and dreamed of one day becoming the doctor on the other side of the chair. 

Dr. Craig earned his dental degree from USC, where he met his wife and business partner, Bethany. Now that they have a practice of their own together, they are proud to bring modern, comfortable dentistry to Altadena. Looking for an experienced dentist in Altadena? Book your appointment with Dr. Craig today!

  • University of California, Riverside
    Bachelor of Science- Biology, minor in Psychology
  • University of Southern California
    Doctor of Dental Surgery 
  • American Dental Association
  • California Dental Association
  • 2019 President of the San Gabriel Valley Dental Society
  • Treasurer of the San Gabriel Valley Dental Society
  • Recipient of the Delta Sigma Delta Distinguished Service Award
  • Recipient of the USC Mobile Dental Clinic Staff Award
  • Regent's Scholarship to the University of California, Riverside
  • Graduated Magna Cum Laude, University of California, Riverside, 2007
  • Creating Digital Media
  • Mountain Biking
  • Is an avid Star Wars & Marvel fan
  • Was a lifeguard and swim coach
Dr. Craig Cheng


Bethany M. Kum, D.D.S.

Born and raised in the Pasadena area, Dr. Bethany Kum was first trained as a dental hygienist and later decided to follow in her father's footsteps by becoming a dentist. She admired her dad’s passion and dedication and knew she had found her calling in dentistry. After graduating from dental school, Dr. Bethany was asked to teach dental and hygiene students as a Clinical Assistant Professor at the Ostrow School of Dentistry of USC. She has taught at USC's clinics located on Skid Row and still currently works with USC's Mobile Dental Clinic and the mobile clinics with Queenscare that travel to different LAUSD schools, providing care to children. 

Dr. Bethany is passionate about educating her patients in an effort to empower them to help prevent dental diseases and infection. As a mother, she has first-hand experience with educating kids on proper oral hygiene- so if you have questions, she is happy to provide advice! Her philosophy is to provide conservative, minimally invasive treatment and is passionate about continuing education. She hopes that by staying up-to-date on the latest dental techniques, she will be able to continue to make her practice the best it can be.

Dr. Bethany is excited to be adding the LightScalpel CO-2 laser to her practice in helping those with tethered oral tissues.  Her studies have been very focused in understanding tethered oral tissues and the impacts it can have during oral development, breastfeeding, and with your overall quality of life.  She understands that releasing any tethered oral tissues is only one part of a successful treatment outcome and will be happy to assemble a team of other providers to help along the way.

  • University of Southern California
    Bachelor of Science - Dental Hygiene
  • University of Southern California
    the Ostrow School of Dentistry, Doctor of Dental Surgery 
  • American Dental Association
  • California Dental Association
  • American Laser Study Club
  • California Dental Association Delegate
  • San Gabriel Valley Dental Society
  • San Gabriel Valley Dental Society Committee Chair
  • The Breathe Institute Ambassador
  • Class President of Her Dental Hygiene Program
  • USC Mobile Clinic Student Director and USC Dr. STAT IV Sedation Team in Dental School
  • Recipient of the Dr. & Mrs. Michael & Kristin Sakaida Lew and Century Club Leadership Award Scholarship
  • Recipient of the USC Academy for Excellence in Dentistry Award
  • Recipient of the USC Civic Engagement Award for Community Service
  • Recipient of the Thor Award for Outstanding Dedication and Service in Providing Dental Care to Underserved and Disadvantaged Children
  • Searching for new foods and desserts to try
  • Working out and trying different workout classes
  • Baking and cooking (Dr. Bethany loves sharing recipes!)
  • Taking cooking classes (So far Dr. Bethany has taken bread, pasta, noodle pulling, and ice cream classes!)
  • Looking for new adventures to enjoy with her family
Dr. Bethany Kum

Empowering Every Patient

Our Approach to Dental Care

At Twenty28 Dentistry, we focus on preventive care because we believe that the best way to treat dental health issues is to avoid them altogether. Prevention and education are at the heart of what we do, and we help each patient maintain a carefree smile through personalized preventive appointments. During routine visits, we will give you all the information you need to ensure that your mouth is a healthy environment for your teeth and gums, and we will always consider your lifestyle, budget, and dental health goals when recommending treatments.

We’re Here to Help

About Our Team

Our close-knit team is upbeat and friendly, and we are dedicated to giving every patient a comfortable, empowering dental experience. Some members of our team have been with us for over a decade, and we work together every day to help every patient put their best smile forward.

Maricela is a chairside assistant with over ten years of experience in patient care, infection control, sterilization, and radiograph imaging. She enjoys working with patients and doctors, alike. Outside of the office, she is dedicated to her family. She loves having fun with her daughter in the pool, cooking with her husband, gardening, and reading the Bible.

Dental Assistant


Myrna is proud to work in an environment with other people who genuinely care about every patient. When you call our office, you will always receive her undivided attention. Myrna’s career in the dental field covers nearly 30 years. She studied dentistry at Bryman College and she has extensive training in dental and medical billing. Myrna regularly attends courses to keep her Registered Dental Assistant license active, which includes training in coronal polishing and x-rays. She has undergone courses in oral sedation and sleep apnea as well. Myrna is originally from Los Angeles, and is happily married with 3 grown children. Outside of work, Myrna’s biggest goal is to visit all 30 Major League Baseball stadiums in the United States.

REgistered Dental Assistant


Bio coming soon!

Dental Hygienist


Lilia is a proud graduate from the Ostrow School of Dentistry of USC's Dental Hygiene program. She was very involved in her class and profession, serving as the treasurer for the Student American Dental Hygiene Association for all 2 years of the program. Lilia has worked in very prestigious offices, focusing on periodontics and prosthodontics for many years. We are happy she is bringing her experience and expertise to Twenty28 Dentistry. Lilia has two daughters and enjoys being a soccer mom on the weekends.

Registered Dental Hygienist


Elizabet’s passion for dentistry began early on. After eight years of working in the dental field as a registered dental assistant, she realized her calling was to become a dental hygienist and was accepted into Pasadena City College’s prestigious dental hygiene program.  In her spare time, she volunteers with the California Dental Association and travels to San Quentin, Mexico for dental outreach mission work with Mission Flight to provide dental hygiene services to those in need. Elizabet values being able to provide the best oral care for her patients and is more than happy to answer questions to help you achieve a healthy, captivating smile.  Raised in Pasadena, California, Elizabet is a natural-born Dodgers Fan, and hopes they will one day win the World Series. During her time off Elizabeth likes to travel, hike, and spend time with her family and pet cat, Leo.

Registered Dental Hygienist


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