Orthopaedics
Orthopaedics aims to develop young growing bones to restore facial harmony and to correct functional imbalances of the bite and other related oro-facial structures such as the airway. The airway is considered to be the single most important factor for survival and thus it is considered a primary determinant of the "functional matrix" which combined with our genetic potential and environment governs the way our faces grow and develop. Lack of development in one or both jaws may have a far reaching effect on our ability to maintain a patent (open) airway during sleep, especially as we age and weight is gained around the neck. Recent investigations into Obstructive Sleep Apnoea have shown a relationship between these factors. It has been suggested that inappropriate orthodontic treatment may be one factor that can predispose an "at risk" individual to OSA. Treatment during this Orthopaedic phase may range from simple supervision and guidance to the use to the use of fixed and removable appliances. These devices either apply direct force to the teeth and craniofacial complex, or stimulate and redirect naturally occurring functional forces.
Expanders
Are a means to permanently widen constricted upper arches and this procedure has the benefits of increasing the space available to align crowded teeth and also may increase nasal airflow which improves some breathing problems. A "Rapid Maxillary Expander" is placed then activated over a 2-3 week period. After this time it is kept in place for a further 6-9 months to retain the correction. Decompensation of the lower arch usually occurs during this period also. Expansion of the upper jaw is best achieved before age 16 as true orthopaedic expansion is gained. As upper arch expansion is much more difficult for adults, they may require surgical assistance to gain the same result.
Twin Block Plates
Are an appliance designed to correctly position the lower jaw relative to the upper jaw and also improve the overall facial appearance. These plates are usually best done prior to braces before the age of 16 years, as the changes that they cause are best incorporated into a growing face. The plates are usually worn for 9-12 months and are adjusted at regular intervals (approximately every 6 weeks). Although the plates are very successful in correcting bite problems they are totally dependant on excellent cooperation and full time wear. As they move the lower jaw into a forward position, they cannot detail the individual position of the teeth, which is done at a later stage with braces.
ADP Face Mask
The AD Protraction Facemask has the widest range of application and produces the most dramatic results in the shortest period for the treatment of Class III malocclusions in the developing dentition. It is our appliance of choice for this problem as the Facemask affects both the skeletal and dental units, which require correction. The ideal time to commence treatment is typically after the eruption of the permanent front teeth, around age 8 years.
For this therapy, three components are needed. Firstly a maxillary expander is modified to include hooks. Secondly the Facemask, which is an extra-oral device, is composed of a forehead and chin pads that are connected by a steel rod to which a crossbow is attached. Thirdly, elastics are used to apply traction to the upper arch from the crossbow to the expander hooks.
The first step of treatment is to fit an expander to the upper arch and to activate the sutures, which attach the maxilla to the skull. This will aid the forward movement of the top jaw. Once the Facemask is fitted the best results are achieved by strong elastic forces, which are applied for approximately 20 hours per day for 4-6 months. After that period appliance wear is reduced to sleep time only for a further 3-6 months.
After the facemask and expander is removed, retainers will be required for a substantial period of time before the final phase of treatment is required in the permanent dentition.
For appliance images visit the Appliances section of the website.