Facial esthetics, balance, and harmony, and/or their absence, have attracted attention from time immemorial, by artist and art viewer alike. Facial expressions can readily reflect various moods, emotions, and feelings, thereby conveying unspoken messages from person to person. The mouth is an essential component of this anatomical–physiological–emotional complex, by virtue of its ability to participate actively in these functions, involving its soft (cheeks, lips, and tongue) and hard (jaws and teeth) tissues. Painters, sculptors, and photographers have noted these features, and frequently, when creating images of human faces, included the rest of the body, or at least the torso, in their artwork, demonstrating acceptance of the principle that the face and the rest of the body are one unit. The specialty of orthodontics is taught predominantly as a field of endeavor dedicated to the improvement of orofacial esthetics and function. Consideration of biological principles and constraints is shadowed by the desire of both the patient and his/her orthodontist to achieve noticeable improvement in the position and location of the malpositioned crown(s), ignoring the fact that the crowns are anchored in the jaws by their roots, which are surrounded by tissues that act and react like any other organ to any local or systemic factor that comes their way. This situation is like an iceberg, visible partially above the water surface, but invisible under it.

Malocclusions are situations where individual teeth or entire dental arches are positioned in undesirable locations, either esthetically or functionally. The goal of orthodontics is to correct or minimize deviations from accepted normal characteristics of dental occlusion, orofacial function, and esthetics. We tend to focus on these deviations from normalcy as the main target of our specialty, while keeping other health‐related issues far in the background, sometimes behind the horizon, as if a malocclusion exists in a vacuum, detached from the rest of the body. Maintenance of this outlook may, however, jeopardize the quality of orthodontic diagnosis, treatment plan, outcome, and long‐term maintenance of the corrected malocclusion. What is required for attainment of optimal results in orthodontics is broadening of its scope, to include other specialties, dental and medical, that may expose etiological factors, and biological processes that could determine the nature of the cellular/tissue response to mechanotherapy. In short, we should not treat a malocclusion, but rather a person with a malocclusion (McCoy, 1941; Kiyak, 2008).

Presently, orthodontics is still viewed by the general population as a field occupied mainly by concerns about facial esthetics, and limited to the application of “braces” or aligners to crooked teeth. This image has been cultivated and nurtured by many members of the orthodontic specialty, because it simplifies their lives by highlighting the known fact that teeth move when subjected to mechanical forces. This outlook is deeply embedded in the curricula of the majority of the orthodontic educational/training programs around the world. Orthodontic residents are made to believe, at least subconsciously, that correcting a malocclusion in a human being is just as easy as moving metallic teeth through the warm, soft wax of a typodont (Davidovitch and Krishnan, 2009). Furthermore, this attitude has encouraged general dentists to engage in the practice of orthodontics without obtaining proper education that would qualify them for this task. An example of a poor outcome of such treatment is seen in Figures 1.1 and 1.2. However, orthodontics, which had been viewed until recently as being mainly a technique‐oriented profession, has evolved into a comprehensive specialty, with a rapidly expanding scope, increasingly interacting with experts, among others, in biology, medicine, dentistry, engineering, and computer science. These interactions can provide the orthodontist with important information pertaining to individual patients that may lead to modifications in the diagnosis and treatment plans.

Voluminous expansion of the scientific and clinical bases of orthodontics is occurring in various directions, biological and technical. The role of biology in the diagnosis, treatment planning, and treatment of individual patients is becoming increasingly clear (Cartwright, 1941; Davidovitch and Krishnan, 2009). An orthodontist may be an expert in mechanics, but he/she is not a nutritionist, psychologist, pediatrician, endocrinologist, primary care physician, oral and maxillofacial surgeon, endodontist, prosthodontist, or any other medical and/or dental specialist. Therefore, it seems only prudent to request advice from other specialists whenever a condition is recognized in a person seeking orthodontic treatment, or in a patient who is already being treated.

The reality is that people who possess malocclusions may also have pathological conditions that could have significant impacts on the course and outcome of orthodontic treatment. This probability creates a need to consult and interact with other specialists familiar with an individual patient, or with the health problem afflicting this individual. Moreover, some people may have communicable diseases that may endanger the well‐being of others who are in their environment. The existence of rapid communication systems enables an orthodontist to easily seek advice from other specialists, leading to the crafting of diagnoses and treatment plans tailored specifically for each individual patient. These systems are also very useful in fostering strong doctor–patient trust, increasing cooperation and improving outcomes.

Likewise, recent advances in material science, metallurgy, and biomedical engineering have introduced an increasing array of alloys, capable of generating a wide spectrum of mechanical forces. A continuous interaction between the orthodontist and these engineers has already produced major changes in the design of orthodontic brackets, and the composition of the metallic and nonmetallic wires that generate the proper orthodontic forces, while controlling factors such as friction and strain. This interaction is fertile ground for the development of new appliances capable of engendering optimal tooth movement, biologically and mechanically, for each patient. The era has come wherein orthodontists are able to print customized brackets and wires tailored for the individual patient and can track individual patient progress with dental monitoring devices. Orthodontics nowadays is largely incorporating reverse engineering in the treatment planning and execution process, wherein malocclusion is treated to its end point with the help of digital models and computerized software and staged sequentially to fabricate aligners.

The pioneers of modern orthodontics were pathfinders in a field full of challenges and obstacles. Those leaders utilized the best therapeutic tools available for eliminating malocclusions, paving the way for greater achievements by their successors. Edward H. Angle, the “father of modern orthodontics,” advocated at the end of the nineteenth century the inclusion of basic medical sciences, such as anatomy, physiology, and pathology, in the curriculum designed for educating dentists as specialists in orthodontics. He apparently clearly saw the functional connection between the head and the rest of the body. Three decades on, one of his students, Albert Ketcham (1929), in attempting to elucidate the reasons for dental root resorption (a major undesirable side effect of tooth movement), concluded that the etiology is associated with the patient’s metabolism. In the following years, resorption of roots was attributed to factors such as nutritional deficiencies, hormonal fluctuations, genetic predisposition, and psychological stress. All these factors point to the fact that tissue remodeling that facilitates tooth movement is dependent, at least in part, on the unique pathophysiological profile of the individual patient. Detailed information on this biological profile may be obtained from several different healthcare providers familiar with individual patients.

However, despite recognition of the importance of life sciences in orthodontic education and practice, considerable emphasis is still being placed on the mechanical aspect of this specialty. Consequently, conditions such as excessive root resorption are labeled idiopathic, unpredictable, and an “act of God.” These explanations fly in the face of the long‐recognized principle of the intimate union between biology and mechanics in orthodontic therapy. This proximity was first suggested by Farrar (1888: 658), who speculated that tooth movement is facilitated by either resorption or bending of the alveolar bone, or by both processes. Farrar’s comment was surprisingly correct, although it was based on empirical evidence. Experimental evidence supporting Farrar’s hypothesis was provided by Sandstedt (1904) and by Baumrind (1969). While Sandstedt used histological sections to demonstrate that paradental cells are responsible for the force‐induced tissue remodeling, Baumrind confirmed in experiments on rats that orthodontic forces do indeed bend the alveolar bone.

The broadening scope of orthodontics

In 2016 the FDI World Dental Federation developed a new definition of oral health that clearly states: “Oral health is multi‐faceted and includes the ability to speak, smile, smell, taste, touch, chew, swallow and convey a range of emotions through facial expressions with confidence and without pain, discomfort and disease of the craniofacial complex (head, face, and oral cavity)” (Glick et al., 2017). Orthodontics fits perfectly within this concept. Based on this definition, the Royal Dutch Dental Association defined orthodontic care as follows: “Orthodontic care is an integral part of oral health care and is concerned with optimizing the position of the teeth and the growth of the jaws and surrounding structures and makes an essential contribution to the health of an individual by promoting their psychosocial well‐being and by creating optimal conditions for other facets of oral health and oral health care” (KNMT, 2020).

Nowadays orthodontics needs this kind of more holistic approach. Ideally, orthodontics should be practiced in a facility that houses all other medical specialists, such as a hospital or a large group practice. In such an environment, reaching various experts and obtaining their advice about health‐related problems of individual orthodontic patients may be accomplished with relative ease. Specialists such as primary care/family physicians, orthopedists, surgeons, psychologists, and nutritionists may be within walking distance from the orthodontic clinic. However, the widespread network of electronic communications today has enabled an orthodontist to refer a patient for consultation and receive the specialist’s opinion in a timely fashion, without dependence on geographical proximity or venue location.

Contemporary orthodontics is a fusion of biology and mechanics, starting with the process of diagnosis, which is based on estimating and documenting the extent of malocclusion, as well as asking: “Who is the patient, biologically?” This question must be answered before any plans for tooth movement can be contemplated. The presence of any systemic or local pathological condition may cause significant alterations in the orthodontic therapeutic plans for any and every individual patient, regardless of age or gender. A comprehensive orthodontic diagnosis should start with a detailed presentation of the patient’s biological profile, including all conditions that may have an impact on mechanotherapy. This segment of the diagnosis is followed by a detailed description of the malocclusion. The biological segment is the part where interaction with specialists in various medical fields is expressed and is later reflected in the crafting of an individual treatment plan. A brief example of such a diagnosis is as follows: “AZ is a 34‐year‐old female nurse, mother of two children, with multiple sclerosis that started 5 years ago, with a history of familial neuropathies. She has a Class II Division 1 malocclusion, with a steep mandibular plane, an 8° ANB angle, and a 12 mm overjet.” This diagnosis is a presentation of the main systemic and orofacial findings, which together pave the way for a proper treatment plan. For the sake of providing the best treatment plan for AZ, it would be beneficial to seek the advice of the other specialists who take care of her, such as her personal physician, neurologist, and nutritionist. Their opinions may turn out to be valuable in guiding the orthodontist toward a treatment plan that would be optimal and practical for this individual patient.

A similar malocclusion in a different patient may read as follows: “RM is a 14‐year‐old boy, entering the pubertal growth spurt, who has type 1 diabetes, allergies, and asthma, with a Class II Division 1 malocclusion, a steep mandibular plane, and an 8 mm overjet.” This concise but detailed diagnosis implies that the patient is growing and has health‐related issues that may overshadow the orthodontic problem and its treatment outcome. Systemic issues of this nature, involving the immune, endocrine, and vascular systems, may alter the response of cells surrounding the teeth to applied mechanical stress, modify the velocity of tooth movement, and contribute to the creation of undesirable side effects to orthodontic treatment, such as irreversible loss of alveolar bone and shortening of dental roots. Moreover, if medical and/or socioeconomic problems are ignored, and are allowed to persist, maintenance of the corrected malocclusion may be jeopardized. Therefore, in the case of RM, it may be advisable for the orthodontist to communicate with the patient’s pediatrician, endocrinologist, and nutritionist prior to solidifying the diagnosis and treatment plan.

The orthodontic patient as a human being