Ozaki Orthodontic Clinic is a private practice limited to orthodontics, located in Ikebukuro, one of Tokyo's principal transport hubs. The practice was established in 1973 by Dr. Takemasa Ozaki and incorporated in 1984 as the medical corporation Shiseikai. It has been directed since 2010 by Dr. Shusaku Ozaki.

The name Shiseikai refers to four commitments we ask of ourselves as clinicians: sincerity in facing each patient, responsibility for providing the most appropriate treatment, continued effort in knowledge and skill throughout our careers, and devotion in the care we give.

Nine orthodontists practise here. Cases are reviewed collectively, so that treatment decisions rest on the judgement of the practice rather than on any one clinician's experience alone. A branch practice, Harajuku Gaien Orthodontics, opened in 2014.

The clinic holds the designations required in Japan to provide orthodontic treatment for congenital craniofacial conditions and jaw deformities under the national health insurance system, including designation as a Specified Medical Institution for Chronic Paediatric Diseases and under the Services and Supports for Persons with Disabilities Act.

Our clinical work is founded on the Tweed-Merrifield philosophy. Dr. Takemasa Ozaki studied at The Charles H. Tweed International Foundation in Tucson, Arizona, and later served as one of its International Directors; the principles he brought back have shaped this practice ever since.

In practical terms this means three things. Diagnosis comes first. Treatment objectives are established from cephalometric, model and facial analysis before any appliance is placed, and the reasoning is explained to the patient. Anchorage is prepared and controlled. The management of reactive forces — invisible in the final photographs — is treated as the structural core of the plan. Treatment proceeds in sequence. Directional forces are applied stage by stage, at a rate the biology of tooth movement allows, rather than at the pace a schedule might prefer.

We regard extraction and non-extraction as means rather than aims. Where space is genuinely deficient, resolving it by expansion alone tends to compromise facial balance and long-term stability; equally, extraction without that analysis is not justified. The decision follows from the records.

New appliances and materials are adopted where they serve these objectives. They are not, in themselves, a treatment plan.

01 Shusaku Ozaki, DDS, PhD

Director and Chairman of the Board, Medical Corporation Shiseikai.

• 2000　Graduated, School of Dental Medicine, Tsurumi University
• 2004　PhD, Graduate School, Institute of Science Tokyo (formerly Tokyo Medical and Dental University)
• 2009　Instructor, Orthodontic Science, Institute of Science Tokyo
• 2010　Appointed Director of Ozaki Orthodontic Clinic
• 2020–present　Clinical Professor, Orthodontic Science, Institute of Science Tokyo
• 2024　Certified Orthodontic Specialist, Japanese Dental Specialty Board

Between 2005 and 2009 he practised at the Orthodontic Department of Yokohama City University Medical Center, where he treated cleft lip and palate, jaw deformity and congenital craniofacial conditions, and subsequently taught at the university dental hospital. He continues to teach in the university clinic several days each month.

02 Takemasa Ozaki, DDS, PhD

Founder of the practice; advisor since 2010.

• 1968　Graduated, School of Dentistry, Institute of Science Tokyo (formerly Tokyo Medical and Dental University)
• 1972　PhD in Orthodontics, Graduate School, Institute of Science Tokyo
• 1973　Founded Ozaki Orthodontic Clinic
• 1982–2008　Part-time Lecturer, School of Dentistry, Institute of Science Tokyo
• 1990–2002　International Director, The Charles H. Tweed International Foundation
• 1995–1996　President, Japan Society of Clinical Orthodontists
• 2002–2008　Clinical Professor, Orthodontic Science, Institute of Science Tokyo

Nine orthodontists practise at the clinic. All are members of the Japanese Orthodontic Society. Oral and maxillofacial surgeons attend on designated days for surgical procedures.

01 Diagnostic Records

Because our treatment objectives are derived from records rather than impressions, the practice maintains the equipment needed to obtain them under standardised conditions: digital lateral and frontal cephalometric radiography, digital panoramic radiography, cone-beam computed tomography, standardised intraoral and facial photography, study models and digital impressions, and — where indicated — mandibular movement analysis and electromyography.

02 Instrument Reprocessing

Instrument reprocessing follows a washing, disinfection and sterilisation protocol, using autoclave and ethylene oxide gas sterilisation according to the instrument. Between them, the two methods allow almost every orthodontic instrument and material to be sterilised.

The practice maintains a continuing connection with university teaching and with the professional societies of Japanese orthodontics.

• Clinical teaching in Orthodontic Science at the Institute of Science Tokyo (formerly Tokyo Medical and Dental University)
• Japanese Orthodontic Society — Councillor (2016–present)
• Tokyo Orthodontic Society — Director (2018–2021)
• Japan Society of Clinical Orthodontists — committee service (2017–2021)
• Toshima City Dental Association — public health committee
• Case and academic presentations at domestic and international meetings

The clinic also works in cooperation with university hospitals, general hospitals, oral and maxillofacial surgery and plastic surgery departments, and local general dental practices.

Colleagues from abroad are welcome. If you would like to visit the practice, discuss a case, or arrange a professional exchange, please contact us using the details below.

01 Location

Poplar Building 10F, 1-14-10 Higashi-Ikebukuro, Toshima-ku, Tokyo 170-0013, Japan
Approximately a three-minute walk from the east exit of Ikebukuro Station, on Sunshine Street. Ikebukuro is served by the JR Yamanote, Saikyo and Shonan-Shinjuku lines, the Tokyo Metro Marunouchi, Yurakucho and Fukutoshin lines, the Seibu Ikebukuro line and the Tobu Tojo line; it is about five minutes from Shinjuku and eleven minutes from Shibuya by train.

02 Consultation Hours

Tuesday to Friday　10:00–13:30 / 15:00–19:00
Saturday and the first Sunday of the month　9:30–13:00 / 14:30–18:30
Closed on Mondays, Sundays (except the first Sunday) and public holidays.

03 First Consultation

All visits are by appointment. An initial consultation lasts 20–30 minutes and costs 3,300 yen including tax. We examine the mouth and jaws, explain the condition and the treatment approaches that may suit it, and outline the likely duration and cost. No decision is required at that visit.

If you wish to proceed, a full diagnostic examination follows (approximately 60 minutes; 66,000 yen including tax, diagnosis included). The treatment plan and the total fee are then presented in writing before treatment begins.

Please note that consultations are conducted in Japanese. Patients who are not comfortable in Japanese are asked to bring an interpreter, or to let us know in advance so that we can advise on how best to proceed.

Ozaki Orthodontic Clinic
Medical Corporation Shiseikai

Poplar Building 10F, 1-14-10 Higashi-Ikebukuro, Toshima-ku, Tokyo 170-0013, Japan
Telephone　+81-3-3981-9679
Website　s-ooc.com

Branch practice: Harajuku Gaien Orthodontics　s-hgo.com