The objectives of functional orthodontic treatment include creating a full broad smile, a pleasing facial profile, a healthy and functional bite and jaw joints, and a stable and lasting result. AAFO members are dedicated to a lifetime of study and practice to achieve the finest results possible for their patients.
Functional orthodontics utilizes the muscles of chewing to promote the proper growth and development of the teeth and jaws. Through the use of various dental devices or appliances, proper tongue and jaw positions are created that eliminate negative forces on the teeth.
Functional appliances are exceptionally good at aligning the upper and lower jaws in growing children. These appliances are usually made of a combination of plastic and wires, similar to a common retainer, but are much more powerful in their effect upon the dentition.
Usually functional orthodontic treatment involves aligning the upper and lower jaws by use of a functional appliance, and then aligning the individual teeth via the use of standard braces. The long term results of this combination of treatment, as opposed to using only standard braces, tend to be more esthetically pleasing and stable.
Orthodontics may be thought of as the dental equivalent of chess. The analogy is appropriate in many respects. The game is played with 32 ivory pieces that are arranged symmetrically about the midline on a board in two equal and opposing armies.
The opening moves are crucial in determining the strategy of the game. From the outset, the game is won or lost depending on the strategy of development of the individual pieces. Indeed, these opening moves can determine whether the game is eventually won or lost.
It is a mistake in chess to become obsessed with the individual pieces. Rather, one must take a broader view and look at the game plan as a whole to maintain a balanced position of the pieces on the board in order to achieve mutual protection and support.
In dental chess, the board is analogous to the facial skeleton, which is of fundamental importance in supporting the individual pieces. As the orthodontic chess game progresses and the dental pieces are developed, the board may become overcrowded with pieces converging upon each other, so that even the most experienced player may at times sacrifice pieces only to realize as the game develops that the gambit was miscalculated.
Only after the passage of time, upon proceeding to the end game, can the success of the strategy be evaluated. Successful treatment is judged in terms of facial balance, aesthetic harmony, and functional stability in the end result. One may conclude that objectives of treatment have been achieved only when the final post-treatment balance of facial and dental harmony is observed.
Orthodontics vs. Dental Orthopaedics
An essential distinction exists between the terms “orthodontics” and “dental orthopaedics.” They represent a fundamental variance in approach to the correction of dentofacial abnormalities.
By definition, orthodontics treatment aims to correct the dental irregularity. The alternative term “dental orthopaedics” was suggested by the late Sir Norman Bennett, and although this has a wider definition than “orthodontics,” it still does not convey the objective of improving facial development.
The broader description of “dentofacial orthopaedics” conveys the concept that treatment aims to improve not only dental and orthopaedic relationships in the stomatognathic system but also facial balance. The adoption of a wider definition has the advantage of extending the horizons of the profession as well as educating the public to appreciate the benefits of dentofacial therapy in more comprehensive aesthetic terms.
A fundamental question that we must address in diagnosis is: Does this patient require orthodontic treatment or orthopaedic treatment, or a combination of both, and to what degree?
An orthodontic approach aims to correct the dental irregularity and is inappropriate in the treatment of what are essentially skeletal discrepancies. By definition, orthodontics must either be combined with dentofacial orthopaedics or maxillofacial surgery in the correction of significant skeletal abnormality.
If the malocclusion is primarily related to a musculoskeletal discrepancy we should select an orthopaedic approach to treatment. It is in the treatment of muscle imbalance and skeletal disproportion that functional orthopaedic appliances come into their own. Functional appliances were developed to correct the aberrant muscle environment — the jaw-to-jaw relationship — and as a result restore facial balance by improving function.
To achieve the best of both worlds it is necessary to combine the disciplines of fixed and functional appliance therapy.
Functional appliances are designed to enhance forward mandibular growth in the treatment of distal occlusion by encouraging a functional displacement of the mandibular condyles downwards and forwards in the glenoid fossae. This is balanced by an upward and backward pull in the muscles supporting the mandible. Adaptive remodeling may occur on both articular surfaces of the temporo-mandibular joint to improve the position of the mandible relative to the maxilla.
In correction of mandibular retrusion, the mandible is held in a protrusive position by occlusal contact on the functional appliance. In this case a large “handle” is attached to as many teeth as possible in both dental arches. The object of a functional appliance is not to move the individual teeth, but to displace the lower jaw downwards and forwards, and to increase the intermaxillary space in the anteroposterior and vertical dimensions. Repositioning the mandible stimulates a positive proprioceptive response in the muscles of mastication. The purpose is to encourage adaptive skeletal growth by maintaining the mandible in a corrected forward position for a sufficient period of time to allow adaptive skeletal changes to occur in response to functional stimulus.