Orthodontic Handbook for Dental Assistants

©2018 Quintessence Publishing Co, Inc

Quintessence Publishing Co Inc

4350 Chandler Drive

Hanover Park, IL 60133

www.quintpub.com

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ISBN 978-0-86715-744-4

All rights reserved. This book or any part thereof may not be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, or otherwise, without prior written permission of the publisher.

Editor: Marieke Zaffron

Production: Angelina Schmelter

Preface

Contributors

1Introduction to Orthodontics

What is Orthodontics?

The Purpose of Orthodontics

Significance of Orthodontic Treatment

The Role of the Dental Assistant in Orthodontic Treatment

Dental Hygiene Practice for Orthodontic Patients

Orthodontic Treatment of Different Conditions

2Growth and Development

What are Growth and Development?

Craniofacial Growth and Development

Development of Tooth Alignment and Occlusion

Development of Oral Function

3Occlusion

Normal Occlusion

Establishment of Normal Occlusion

Malocclusion

Disorders Caused by Malocclusion

4Orthodontic Diagnosis

The Flow of Orthodontic Treatment

Necessary Analysis for Treatment

Case Analysis

5Orthodontic Forces and Craniofacial Orthopedic Forces

Orthodontic Force

Types of Tooth Movement

Biologic Tissue Change with Tooth Movement

Anchorage

6Orthodontic Treatment Materials and Instruments

Orthodontic Treatment Materials

Orthodontic Instruments and Devices

Assisting Orthodontic Treatment and Providing Patient Instruction

7Orthodontic Appliances and Orthodontic Treatment

Types of Orthodontic Appliances and Their Features

Retention

Complications of Orthodontic Treatment

8Clinical Case Presentations of Orthodontic Treatment

Crowding

Maxillary Protrusion

Mandibular Protraction

Maxillary and Mandibular Protraction

Overbite

Open Bite

Crossbite

Cleft Lip and Cleft Palate

Jaw Deformity

Minor Tooth Movement

Impacted Teeth and Abnormal Number of Teeth

9Oral Hygiene During Orthodontic Treatment

Oral Hygiene During Orthodontic Treatment

Plaque Control

Instruction on Eating Habits

Steps of Oral Hygiene Management

Oral Myofunctional Therapy

Appendix

Recommended Reading

Orthodontics and dentofacial orthopedics is the dental specialty that includes the diagnosis, prevention, interception, and correction of malocclusion and neuromuscular and skeletal abnormalities of the developing or mature orofacial structures. The number of dentists who provide orthodontic treatment is rapidly increasing, and with it the need for orthodontic assistants who understand the fundamental concepts and clinical aspects of orthodontics. This textbook contains the scientifically oriented facts and clinical fundamentals required for dental assistants’ education.

At the beginning of the each chapter, the learning objectives are listed, and at the end of the each chapter, a review quiz is available to evaluate proficiency. Learning should be completed with preparation and review. The textbook covers deeper subjects for enhanced comprehension.

We hope that this textbook will help the dental assistant learn aspects of not only orthodontics but also dentistry in general, with a focus on good communication between dentists and individuals dedicated to public health.

Kazuhito Arai, DDS, DDSc

Professor and Chair

School of Life Dentistry at Tokyo

The Nippon Dental University

Tokyo, Japan

Yasuyuki Iizuka, DDS, PhD

Assistant Professor

School of Dentistry

Iwate Medical University

Morioka, Japan

Kazutaka Kasai, DDS, PhD

Specially Appointed Professor

School of Dentistry at Matsudo

Nihon University

Matsudo, Japan

Tomoe Komori, BCom, RDH

Part-time Lecturer

The Nippon Dental University College at Tokyo

Tokyo, Japan

Kotaro Maki, DDS, PhD

Professor

School of Dentistry

Showa University

Tokyo, Japan

Naoyuki Matsumoto, DDS, PhD

Professor

School of Dentistry

Osaka Dental University

Hirakata, Japan

Hisayo Mayama, DDS, PhD

Associate Professor

School of Dentistry

Iwate Medical University

Morioka, Japan

Hiroyuki Miura, DDS, PhD

Vice President, Dean

Professor

School of Dentistry

Iwate Medical University

Morioka, Japan

Takuma Mizukawa, DDS, PhD

Director

Motomiya Mizukawa Orthodontic Clinic

Morioka, Japan

Yoshiki Nakamura, DDS, PhD

Professor Emeritus

Tsurumi University

Yokohama, Japan

Souichiro Oda, DDS, PhD

Oda Orthodontics

Tokyo, Japan

Takashi Ono, DDS, PhD

Professor

Graduate School of Medical and Dental Sciences

Tokyo Medical and Dental University (TMDU)

Tokyo, Japan

Kazurou Satoh, DDS, PhD

Professor

School of Dentistry

Iwate Medical University

Morioka, Japan

Naoto Suda, DDS, PhD

Professor and Chair

School of Dentistry

Meikai University

Sakado, Japan

Akihiro Suzuki, DDS, PhD

Assistant Professor

School of Life Dentistry at Tokyo

The Nippon Dental University

Tokyo, Japan

Osamu Takahashi, DDS, PhD

Director

Takahashi Orthodontic Clinic

Tokyo, Japan

Kae Wakabayashi, DDS, PhD

NAKANO Orthodontic Clinic

Morioka, Japan

Hiroyuki Yamada, DDS, PhD

Director

Aile Dental Clinic

Maebashi, Japan

Tetsutaro Yamaguchi, DDS, PhD

Professor

School of Dentistry

Kanagawa Dental University

Yokosuka, Japan

LEARNING OBJECTIVES

•Understand the field of orthodontics.

•Understand the definition of orthodontic treatment .

•Understand the purpose of orthodontic treatment.

•Understand the definition of malocclusion .

•Understand the adverse effects of not managing malocclusion.

•Understand the role of the dental assistant in orthodontic treatment.

What is Orthodontics?

Most people are familiar with orthodontic treatment. A lot of information can be acquired online or in books; therefore, awareness of orthodontics is relatively high. The definition of orthodontics is the treatment of irregularities in the teeth and jaws. But how does the public perceive orthodontic treatment in modern society?

An awareness survey of teeth alignment and orthodontic treatment involving 1,000 men and women aged 10 to 50 years showed that most people think that tooth alignment determines one’s first impression and is therefore important for facial esthetics. The survey also showed, however, that people’s knowledge of the symptoms of tooth malalignment was quite low. Dental professionals should understand that orthodontic treatment is not only for facial esthetics.

The term malocclusion in orthodontics is defined as the misalignment of teeth or the incorrect relationship between maxillary teeth and mandibular teeth in intercuspation. Many variables cause malocclusion, classifying it as a syndrome. For example, simple malocclusion can be caused by oral habits such as mouth breathing or thumb sucking, whereas more severe malocclusion can be caused by congenital or acquired medical conditions, facial trauma, or severe periodontal disease (Fig 1-1). However, the condition can still be diagnosed as malocclusion regardless of the causes and symptoms. Irregular occlusion can occur at a variety of ages and with a variety of severities and states of oral function. Orthodontic treatment should be appropriate to the stage of physiologic and morphologic components of the condition, as well as the stage of the patient’s mental development.

Fig 1-1 Origins of malocclusion.

Orthodontics involves the study of dental growth and development, including research of dental arches and occlusal growth and development throughout a person’s life. It also involves the field of oral functional systems, including research of morphologic and functional improvement.

Orthodontics in modern society can be defined as follows:

Orthodontics is a dental specialty field that embraces research and study of the management of teeth malalignment and malocclusion. The purpose of orthodontics should be to provide healthy functional and esthetic dental arch and occlusion to patients to improve their quality of life.

The Purpose of Orthodontics

As previously stated, orthodontics is a specialty that treats patients’ malalignment and malocclusion in the dental arches. Malocclusion has several variables, and considerable complications may arise if it is left untreated (see Fig 1-2).

Fig 1-2 Representative malocclusion. (a) Crowding. As a result of an irregular tooth, the positional abnormality of individual teeth spans several teeth. (b) Maxillary overjet. The maxillary anterior teeth are markedly inclined to the labial. (c) Mandibular underbite. The maxillary and mandibular occlusion is reversed. (d) Crossover occlusion (crossbite). Maxillary and mandibular occlusions are laterally displaced. (e) Open bite. The anterior teeth are not in contact even in the occlusal position. (f) Overbite. The state of occlusion is so deep that the mandibular anterior teeth cannot be seen at the occlusal position.

The eight objectives of orthodontic treatment are as follows:

•Prevention of dental decay.

•Prevention of periodontal disease. If malocclusion is untreated, dental decay and periodontal disease may occur easily because of the difficulty of maintaining sufficient oral hygiene. Also, malocclusion makes dental decay management difficult for the dentist ( Fig 1-2a ).

•Prevention of oral trauma. Patients with maxillary protrusion have a high tendency to undergo maxillary anterior teeth trauma (fracture or avulsion) during sports ( Fig 1-2b ).

•Improvement of speech difficulties. Mandibular protrusion ( Fig 1-2c ) and open bite ( Fig 1-2e ) may cause speech difficulty with the following sounds: s, z, p, b, m, w, t, d, and n.

•Improvement of mandibular movement. Crossbite ( Fig 1-2d ) and overbite ( Fig 1-2f ) may cause unwanted posterior and lateral mandibular movement, which may in turn become precursors to a temporomandibular disorder.

•Improvement of breathing disorders. Patients who have abnormal craniofacial development, such as a retropositioned or small mandible, are known to have a high frequency of sleep apnea. Sleep apnea can also be found in children with large adenoids.

•Improvement of masticatory and swallowing dysfunction. Masticatory dysfunction frequently occurs in patients with mandibular protrusion because their maxillary and mandibular teeth cannot have normal contact during mastication. Tongue thrusting during swallowing is found frequently in patients with open bite.

•Improvement of facial esthetics. The patient’s attitude can be positively altered by improving his or her tooth alignment and facial esthetics. Although all objectives of orthodontic treatment are important, the patient will not be satisfied unless he or she is happy with the esthetic result.

Significance of Orthodontic Treatment

The World Health Organization (WHO) defines health as a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity. Considering this definition, orthodontic treatment should contribute to a patient’s physical, mental, and social well-being and improve the patient’s quality of life by achieving all eight objectives of orthodontic treatment listed in the previous section.

However, as the structure of modern society changes constantly, orthodontic treatment needs to be modified accordingly.

Diversification of patients

Although dental professionals will continue to see an increase in older orthodontic patients, younger patients still require orthodontic treatment. Congenital malocclusion patients, for example, will need to be managed by the orthodontist from birth. Also, orthodontic treatment for developing children will always be in demand. Orthodontic treatment will have more diversification in modern society. It is important to understand the changes in society and to provide orthodontic treatment accordingly.

The Role of the Dental Assistant in Orthodontic Treatment

Orthodontic treatment in modern society is diverse and depends on the patient’s age and chief complaint; therefore, treatment considerations can vary. It is easy to understand that treatment considerations differ for adult, infant, and child patients. Communication with the guardian is very important for orthodontic treatment in infants and children. It is also important that the treatment accommodate any age group and that any treatment anxiety be eliminated. Orthodontic treatment should be carried out in accordance with evidence-based medicine (EBM). However, because the treatment can last a long time, it should be also carried out in accordance with narrative-based medicine (NBM), which focuses on the patient’s demand and complaint. It is important that medical professionals display kindness and compassion to patients and that they provide safe, reassuring, and consented medical treatment.

Dental assistants as well as dental hygienists primarily provide dental health guidance and dental treatment assistance to patients based on the philosophies of dental disease prevention and oral hygiene. However, dental assistants also have a role in orthodontic treatment. The roles and characteristics of the dental assistant in the orthodontic treatment are briefly summarized in the following sections.

Management and instruction of oral hygiene

•Oral hygiene instruction and management for the orthodontic patient. The importance of oral hygiene practice during treatment and the instruction of orthodontic devices needs to be explained to the patient before orthodontic treatment begins.

•Actual oral hygiene instruction including brushing and oral hygiene management ( Fig 1-3). Because orthodontic patients have some kind of orthodontic devices in their mouth, oral hygiene instruction including brushing needs to be modified accordingly.

•Preventive instruction. Dental decay prevention during orthodontic treatment should be instructed and should include topical fluoride treatment or a fluoride rinse ( Fig 1-4).

•Dietary and eating instruction. Instructions for diet and eating need to be provided to the orthodontic patient. This instruction should cover nutrition as well as characteristics of the food that the orthodontic patient consumes.

Fig 1-3 Images showing (a) professional mechanical tooth cleaning and (b) oral hygiene instruction immediately after placement of a multibracket appliance.

Fig 1-4 Intraoral images of a patient receiving multibracket treatment immediately after plaque staining (a) and professional mechanical tooth cleaning (b).

Instruction of oral function

Oral myofunctional therapy improves oral function. Open bite or maxillary protrusion may occur in children as a result of thumb-sucking or tongue-thrusting habits. Oral myofunctional therapy is quite effective as a supplemental therapy for those patients.

Assisting with treatment

Dental assistants also provide support to dentists performing orthodontic treatment. They may assist with:

•Orthodontic device insertion

•Multibracket appliance