About Us | 4M Dental Implant Center

The Doctors at 4M Dental

With thousands of implants placed, the doctors at 4M Dental Implant Center have successfully taken on some of the most complex cases. Dr. Sean is a leader and educator in the field of dental implants – at the forefront of what’s happening in the industry – and passes his knowledge on to his associates. Through the 4M Institute (located in our Long Beach facility), Dr. Sean teaches the art and science of the All-on-X solution to dentists from around the world. His years of experience and wealth of knowledge enable us to educate our patients on their best options and what to expect.
Love Your Smile Again at 4M Dental Implants!
Dental implant center where professionals provide full mouth dental implants
The dentists and techs at 4M Dental Implant Center

Meet Our Doctors

Choosing to invest in dental implants is a big decision. There are many dentists who say they specialize in full-arch dental implants. So what makes us any different? Quite a lot, actually.

A male medical professional specializing in whole mouth dental implants, wearing a blue scrub suit, sits smiling in a bright clinical laboratory setting.

Sean Mohtashami, DDS

Dr. Sean is a leading authority on full-mouth dental implants and is a world renowned expert in cosmetic dentistry. He truly knows how to design a beautiful and personalized smile.

Upon graduating from the USC School of Dentistry he continued his quest for knowledge and completed many specialty programs in his field. Deeply committed to education, in 2018 Dr. Sean created his own institute for learning in Long Beach, CA, and is currently teaching and mentoring doctors from around the world.

This, combined with over 20 years of practical experience, has made Dr. Mohtashami a Top 100 Implant Surgeon worldwide.

Samira Houshiar, DDS

Dr. Samira Houshiar graduated UCI with honors receiving her bachelor’s degree in Biology in 1997. In 2001 she received her Doctoral in Dental Surgery (DDS) from UCLA school of dentistry and since she has continued her education in many different dental subspecialty programs.

Soon after receiving her DDS, she continued her education in cosmetic dentistry at LVI (Las Vegas Institute) and graduated in 2003. While practicing cosmetic and general dentistry, she completed her certification in Occlusion, Neuromuscular, and TMJ treatment concurrently. In order to bring more comfort for her most anxious patients, Dr. Samira completed the training necessary to be certified in Conscious Sedation (2004) and I.V. Sedation (2020).

Since completing her assistant fellowship in Implantology back in 2009, Dr. Samira has dedicated her career to full mouth reconstruction and designing beautiful and functional smiles for her patients. She is currently practicing at 4M Dental Implant Center at the Newport
Beach location. Dr. Samira Houshiar is a firm believer that the road to quality has no finish line. She is dedicated to staying at the cutting edge of technology and all dentistry has to offer. She is determined to change lives one smile at a time.

A healthcare worker in a mask and gloves conducts a throat swab on a seated patient in a medical clinic.
A dentist wearing a mask and gloves examines a patient's teeth for whole mouth dental implants while an assistant helps during the procedure.

Athena Goodarzi, MS, DDS

Dr. Athena graduated from The University at Buffalo School of Dental Medicine, one of the top dental programs in the nation. She completed her residency at the College of Physicians & Surgeons of Columbia University, New York City.

Dr. Athena’s area of expertise is full mouth rehabilitation through the All On X Dental Implants Solution. She strives for excellence and is passionate about utilizing her research and academic teaching background to share her unique skills in full mouth rehabilitation with colleagues, whom she mentors across the nation. Dr. Athena takes pride in teaching full arch restorative concepts alongside Dr. Sean Mohtashami at 4M institute. 

Dr. Athena’s skills in blending art with function are unique, but her attention to detail and gentle approach to dentistry are what stand out the most. Dr. Athena’s ability to connect with her patients, create relationships, and design the best treatment possible makes her the perfect addition to our team.

Dr. Athena has profoundly affected the smiles and lives of many of our patients globally and would love to do that for you, too.

Philip Konopa, DDS

Dr. Phil received his doctoral degree from the University of Washington and completed his residency at the University of California, Los Angeles (UCLA). 

His skills and experience enable him to excel in full-service general and cosmetic dentistry with an emphasis on comprehensive/reconstructive procedures.

Dr. Konopa is well versed in fixed restorations & aesthetics, and helps our patients achieve a beautiful, functional smile they are proud to show the world.

Dentist in protective gear showing a female patient her teeth in a mirror during a dental examination.
A smiling man with graying hair, dressed in a blue suit and white shirt, stands in front of a bright, blurred background.

Derik Alexanians, DDS

Upon graduating from UCLA, Dr. Derik has made Southern California his home and has been practicing dentistry here for over two decades.

His comprehensive knowledge of restorative dentistry techniques such as extractions, bone and tissue grafting, implant surgery & placement through the use of oral and IV sedation, allows him to provide unparalleled care.

Dr. Derik is our Clinical Director. He will light up your day with his contagious smile and is one of the best people you’ll ever meet.

Kostika Polena, DDS

“I believe everyone deserves the benefit of a happy and healthy smile. As your dental provider, I am committed to helping you overcome any barriers preventing you from receiving the best oral health care possible.”

Early on Dr. Polena discovered a love and talent for art and later for science, graduating from UNLV with a degree in Biochemistry. Dentistry has turned out to be an ideal blend of his two passions. For Dr. Polena, dentistry has been a tremendously rewarding experience thus far and looks forward to a long career and enduring relationships with his patients.

Dr. Polena’s patients will quickly recognize the quality and the personal dental care he delivers. Through effective treatment plan presentation and patient communication, he has been able to consistently exceed patient expectations.

Dr. Polena excels in dental implants, extractions, dentures/partials, crowns and bridges, laser dentistry, Invisalign, and more.

An image of Dr. Polena at 4M Dental Implant Center in Las Vegas
Professional man with dark hair and beard, wearing a gray blazer and white shirt, smiling in an office environment.

Tira Emadi, DDS, MS

Dr. Emadi is a specialized implant-prosthodontic surgeon practicing in Long Beach, CA. He received his Doctor of Dental Surgery degree from Tehran Azad University of Dentistry, Tehran, Iran in 2009. Dr. Emadi has practiced general dentistry for several years. He was a prosthodontics preceptor at the University of California, San Francisco before he entered Nova Southeastern University (NSU) College of Dental Medicine in Ft. Lauderdale, FL where he received his specialty certificate in Prosthodontics and his Master of Science in Dentistry.

During his residency, at NSU, Dr. Emadi served as a Chief Resident and was honored with the dental implant surgery award. Dr. Emadi completed the Maxicourse dental implant education in the American Academy of Implant Dentistry. He also excels in digital dentistry. 

Dr. Emadi is passionate about researching, practicing, and teaching on Various topic including Single implants, Bone graft, Sinus lift, Overdenture, digital workflow, and full mouth dental implant rehabilitation. He has more than twenty-five presentations in different dental meetings and has published several papers in peer-reviewed dental journals. His presentation at the 70th AAID annual conference received first-place award and he received a second-place award on his presentation in 29th Academy of Osseointegration Annual Meeting.

1. Implant Rehabilitation After a Partial Resection of the Mandible Resulting from Submandibular Gland Malignancy-A Case Report. J Oral Implantol. 1 June 2022; 48 (3): 220–225.

2. Full Mouth Rehabilitation Using Dental Implants with Immediate Loading in a Systemic Sclerosis Patient; A Case Report. Inside Dentistry. 2021 July; 17(7).

3. Immediate Implant Placement and Provisionalization in the Esthetic Zone Using Flapless Technique. Compendium of Continuing Education in Dentistry. 2021 July/Aug;7(42).

4. Oral rehabilitation of a patient with ankylosing spondylitis and orofacial pain: A case report. Surgery and Rehabilitation. 2017 Sep;1(3) 1-5.

5. Effect of Surface Treatment on Retention of Prefabricated Glass-fiber Posts. Journal of Universal Surgery. 2016 Feb;3(5).

6. The Effects of Two Attachment Types on the Stresses Introduced to the Mandibular Residual Ridge; A 3D Finite Element Analysis. Quintessence International. 2013 Sep;44(8):585-590.

7. Stress Introduced by Two Attachment Types in Four Implant-retained Overdenture; A 3D FEA Study. Research in Dentistry. 2009 Jul;6(2):9-17.

Kamran Pakdamanian, DMD

Dr. Kamran Pakdamanian’s professional journey is marked by commitment to excellence and patient-centered care. In 2023, he proudly earned his Doctor of Dental Medicine (DMD) degree from the esteemed Western University of Health Sciences, laying a strong foundation for his career in dentistry.

Recognizing the importance of patient comfort and accessibility to care, Dr. Pakdamanian obtained certification in I.V. Sedation, furthering his expertise to offer anxiety relief for patients. By integrating his education and I.V. Sedation Certification, along with specialized training in All-On-X Implant Dentistry, Dr. Kamran exemplifies his dedication to excellence. Through his holistic approach, he ensures that patients receive the highest standard of care, addressing both their oral health needs and their comfort during procedures.

Kal Eissa, DDS

Dr. Kal Eissa received his High School Diploma from Cambridge, UK, his dental degree from University of Cairo, and his Continuing Education from the University of Minnesota. Dentistry is a profession that allowed Dr. Eissa to positively impact people’s lives almost immediately. “It’s a great feeling!” says Dr. Eissa. “Few professions can give you this privilege. I’m lucky to be in one.”

Ninella Bogosian, DMD, FICOI

Dr. Bogosian is a highly motivated, caring, and compassionate dentist who always takes the time to understand her patients. Utilizing the latest technology, she ensures patients are comfortable and informed during all procedures. Her calm demeanor and advanced
knowledge can help to put even the anxious patient at ease.

After earning a bachelor’s degree, Dr. Bogosian proceeded to follow her passion by earning a Doctor of Dental Surgery degree at the University of Arizona in 2020.

Understanding the importance of being a life-long learner, Dr. Bogosian has taken numerous continuing education courses related to Prosthodontics, Biomimetics and Cosmetic Dentistry. She also completed additional extensive training in implant dentistry and is a Fellow of International Congress of Oral Implantology. Her focus is on
oral surgery and implant dentistry involving full mouth reconstruction (All-On-X Dentistry).

She is a member of the American Dental Association, Academy of General Dentistry, American Academy of Cosmetic Dentistry, American Academy of Implant Dentistry, International Congress of Oral Implantology, and American Academy of Facial Esthetics.

Ninella Bogosian, DMD, FICOI
Three professionals, two men and one woman, smiling and standing together in an office with a sign that reads “dental implants” in the background.