Oral and maxillofacial system is a complex composed of mountain teeth, periodontal supporting tissue, jaw, yimandibular joint, oral and maxillofacial nerves, muscles and other related tissues, which coordinate and restrict each other. The oral and maxillofacial system continues to undergo various forms of adaptive reconstruction in people's life. This change is particularly obvious in the peak period of human growth and development. The poor function of lip, tongue, maxillofacial muscles and other tissues is also one of the important factors in the etiology and development of many malocclusion deformities.

        As early as more than 200 years ago, people realized the importance of muscles and nerves to the development of the maxillofacial region. In 1726, France

        Fauchard was the first to use a regulation appliance, To develop dental arch to achieve "Ideal" bow. In 1771, hunten, a British surgeon, first accurately analyzed the growth of the mandible and published articles on the structure, formation, growth, function and disease of human teeth and the principle of malocclusion correction. These theoretical foundations played an early enlightenment role in the development of functional orthopedics. In 1808, Catalan in France used mandibular inclined guide plate to treat mandibular protrusion, which was honored as Kingsley, the "father of Orthodontics", also designed an maxillary inclined guide plate to guide the forward growth of the mandible, established the treatment idea of mandibular forward, and published an article in 1880, officially proposed the inclined guide plate appliance to treat mandibular retrusion deformity, and carried out the first of functional orthopedic treatment. At the same time, he also proposed extraoral anchorage for the correction of         maxillary protrusion, which is still widely used in the correction of thousands of maxillary protrusion.

        In 1902, inspired by Kingsley's thought, Robin of France designed an upper and lower conjoined appliance, also known as "monoblock appliance", to change the sagittal position of the jaw to affect muscle activity. His method is widely used in France and Belgium. For example, Dr. watry highly praised this monoblock correction technology. He believes that the appliance can be used as a training device for facial muscles. The design principle of today's widely used biological regulator is to change the position of the tongue, which undoubtedly belongs to thousands of Robin's monoblock.

        In 1910, Andresen Zhensheng of Denmark designed a muscle agonist (activator), known as a milestone in the field of functional appliances.

        In 1936, Dr. Andresen and Dr. haupl published functional jaw orthopedics, which further laid the basic theory of functional appliances. The book proposes "functional jaw orthopedic" to distinguish "dental orthopedic", forming the so-called Norwegian system. The basic idea of the so-called Norwegian system, That is, the composition of maxillofacial is not a simple "normal ideal concept", nor can it be reflected by the average value of Biostatistics, and individual variation is a normal phenomenon "Individualized function and aesthetics are the most suitable". It is proposed that the purpose of the system is not only to achieve normal powder, but to make patients have healthy periodontal function all their life. 23 advantages of functional appliance are summarized. It is considered that functional appliance can passively change the position of mandible and the chewing type of patients, make mandible adapt to new position, reposition teeth and change the growth direction of mandible. They also observed functional appliance The therapeutic apparatus has the function of "shaking bone substance", which increases the activity of osteoblasts and leads to the increase of bone formation.

        In 1967, German doctor Frankel developed Frankel function regulator or Frankel appliance after improvement on the basis of his predecessors. The appliance is mainly composed of buccal screen and lip block, which is characterized in that the buccal screen leaves the dental arch, blocks the pressure of lip buccal muscle and expands the dental arch. He regarded the buccal shield and lip block as a muscle trainer, which is called the "functional matrix" suitable for the shape of dental arch. In addition to the buccal muscle and perioral soft tissue, which have a potential inhibitory effect on the development of dental arch, it can expand the alveolar bone and move the dental arch to the buccal side as a whole. It can also solve the bad posture and behavior and establish a normal oral functional space. Additional functionality

        The appliance can also guide the growth, regulate the direction of facial growth, and establish a good functional form. It can avoid iatrogenic trauma caused by fixed appliance, absorption of root and alveolar bone, dental caries, poor oral hygiene and so on. 1967—

        In 1987, Frankel successively published articles, lectures and displayed cases in Europe, the United States and other countries, which was warmly welcomed and highly praised by the American orthodontic community, and eliminated the prejudice of the American orthodontic community against the thousand function appliance. In 1985, the famous American orthodontic scholar Graber compiled the book functional orthodontics and functional appliances, which further promoted the development of functional orthodontics.

        In the late 1980s and 1990s, functional orthopedics has been widely carried out and applied in many countries. It has become the main means of early treatment and has made new development in theoretical research. Moss further put forward the concept of "epigenetic control" on the basis of his "functional matrix" hypothesis. He believes that endogenous factors (i.e. heredity) and exogenous factors (epigenetics factor) during growth and development Under the joint action. In other words, the growth and reconstruction of craniofacial growth areas is a comprehensive response of the whole group of genetic information and evolutionary information. The biological machinery and biophysical parameters of developing organisms can be affected by any functional mechanical force. The proposal of this concept not only makes us have a deeper understanding of craniofacial morphology, but also provides a theoretical basis for orthopedic treatment. Modern functional appliances have made many improvements on the basis of muscle agonists, forming a variety of appliances with their own characteristics, which interact with each other, learn from each other and constantly improve. Such as Herbst appliance and Jasper Jumper appliance improved on this basis; Clark designed twin block appliance for convenient chewing and use.