The retractive philosophy is still extremely prevalent in the orthodontic profession worldwide. It involves the treatment of patients mainly in permanent dentition with the use of fixed orthodontic braces, extractions, and the use of extra-oral cervical headgear sometimes.
Proponents of this technique rationalise the following:
1. Crooked teeth as a result of crowding are due mainly to the fact the patients’ teeth are too large for the size of the arch. Therefore, rather than develop the constricted arch to normal they prefer to extract teeth, usually the bicuspids.
2. When the patient presents with a moderate overjet, proponents of the retractive technique believe that the best solution would be to extract the upper bicuspids and retract the 6 anterior teeth into the extraction sites.
In the majority of cases with Caucasian patients that present with class II, div I malocclusions with moderate overjets the problem is not a prognathic maxilla but rather a normally positioned maxilla and a retrognathic mandible. Therefore, if the 6 anterior teeth are retracted this can result in the patient ending up with a much less favorable concave profile. The upper lip is more deficient, the nose appears longer and in some cases the patients ends up with a midface deficiency. These cases are easy to diagnose. In class II, div I malocclusions with a moderate overjet ask the patient to move the lower jaw forward end to end. If the profile drastically improves then this patient requires a functional appliance to move the deficient mandible forward to its proper position. Extractions in this case would be contra-indicated.
In cases where the maxilla is truly prognathic then the retractive technique is acceptable.
The other serious problem is that if extractions are done in a patient whose condyles are posteriorly displaced this can lead to TMJ problems in the future. The extraction of the two upper bicuspids and the subsequent retraction of the six anterior teeth virtually traps the mandible which prevents the mandible and condyles from assuming their normal forward position. This can, in some cases, compress the nerves and blood vessels distal to the condyle and cause temporomandibular joint dysfunction (TMD) later on.
The extraction of two upper first bicuspids also results in the constriction of the maxillary arch as a result of the removal of 16mm of tooth structure. This is in violation of what I believe to be the most important keys to overall health which is to establish a proper size maxillary arch. Failure to properly diagnose and treat patients in mixed dentition can have a profound effect on their overall health. The key is to learn to diagnose and treat our children in mixed dentition with a functional philosophy.
Recently more dentists have become involved in the diagnosis and treatment of the life-threatening medical disorder, obstructive sleep apnea (OSA). It has been estimated that approximately 20 per cent of the adult population has the problem and although obesity plays an important role, a large number of patients have class II, div I malocclusions with large overjets and underdeveloped mandibles. A common cause of OSA is when the tongue falls back and blocks the airway for 10 seconds or more. The consequences of undiagnosed and untreated obstructive sleep apnea are an increased risk of high blood pressure, heart attacks, strokes, type 2 diabetes, impotence, memory loss, depression, acid reflux and dementia. Many patients are prescribed a CPAP device which consists of an air compressor that blows air up the nose all night. While very effective when worn the failure rate with CPAP is high. The alternative treatment is often an oral appliance fabricated by a dentist with special training in the area of sleep disorder dentistry. The American Academy of Sleep Medicine (sleep specialists) recommends oral appliances as the first treatment option or patients with mild to moderate sleep apnea.
It is important that general dentists either learn how to treat their younger patients in the mixed dentition or refer their patients to an orthodontic clinician with a functional philosophy.
The many advantages that I have discussed include eliminating the need for the extractions of permanent teeth or orthognathic surgery. Arch development allows for a beautiful broad smile and increased size of the nasal airway which increases the patient’s level of oxygen. Patients treated with the functional philosophy have improved TMJ health and reduced tendency to have the life threatening medical disorder obstructive sleep apnea.
A child’s future health problems do depend on how their orthodontic-orthopedic-TMJ problems are treated in the mixed dentition.