Tooth movement: Health science or cosmetic dark art?
By Dr. Rohan Wijey, BOralH, Grad Dip Dent (Griffith)
Most medical students around the world recite an oath equivalent, or similar to, the Oath of Hippocrates.(1) It is perhaps a sad indictment on the dental profession that most students of our schools undertake no such pledge of care to their future patients.
When we graduate as dental hygienists, dentists or specialists, however, we are all implicitly bound to honor the trust placed in us as "medical professionals."
Despite our status as "medical professionals," it is the orthodontic profession that has most conspicuously veered away from being a health science; we have moved more towards a dark art dealing purely with cosmetics, at the expense of our children’s health.
Premolar Extractions
There is no better example than the prevalence of premolar extractions in private practice. Epidemiological data is sparse, but according to the most contemporary survey conducted of U.S. private practices, 25%-85% of our children have healthy teeth extracted in the name of orthodontics.(2)
The justification and rationale behind premolar extractions today rests with P.R. Begg’s 1954 assertion that the low incidence of malocclusion in primitive dentitions was due to gritty diets causing interproximal attrition; Begg suggested that this amounted to a premolar’s width in each quadrant.(3)
Begg’s research has been roundly refuted in the literature,(4) not least because his own theory refutes his results: both crowding and attrition increased with age.
Do premolar extractions lead to more stability?
No. Little’s definitive 1981 study showed satisfactory mandibular anterior alignment in less than 30% of cases 10 years post-retention.(5) Many other studies have corroborated this conclusion.
Although hygienists, dentists and all other specialists strive to preserve teeth, this principle seems outside the orthodontic profession’s orbit of thinking.
“Whenever there is a struggle between muscle and bone, bone yields,” wrote Graber in his seminal 1963 manifesto on the influence of muscles on malformation and malocclusion.(6) In their review of the orthodontic influence of mandibular muscles, Pepicelli et al. (2005) corroborate it is “well accepted” that the position and function of the facial and mandibular muscles are “critical influences” on alignment and stability.(7)The weight of the literature rests with the fact that muscle function and posture (the way patients swallow and posture their tongue) is the most significant cause of malocclusion.A question of morality?
Since the epidemiologist Sackett observed in 1986 that orthodontics was en par with Scientology in terms of scientific legitimacy,(8) the industry has made a concerted attempt to change its image.However, if we aspire to be considered a serious, medical profession, Orthodontics must jettison anachronistic relics of an unscientific past, and re-orientate itself towards a more health-based approach.It is therefore incumbent on all of us to make a stand, and not be afraid to question whether our patients are truly receiving health care from the local orthodontist, or whether they are simply being condemned to the orthodontic ‘four on the floor’ production line.References
1. Antiel RM, Curlin FA, Hook CC, Tilburt JC (2011) The impact of Medical School Oaths and Other Professional Codes of Ethics: Results of a National Physician Survey. Arch Intern Med 171 (5) 469-471. 2. Weintraub JA, Vig PS, Brown C, Kowalski CJ (1989) Prevalence of orthodontic extractions. Am J Orthod 96 (6) 462-466.3. Begg PR, (1954) Stone age man’s dentition. Am J Orthod 40 298-3124. Corruccini RS (1990) Australian aboriginal tooth succession, interproximal attrition, and Begg’s theory. Am J Orthod 97 (4) 349-357. 5. Little RM, Wallen TR, Riedel RA (1981) Stability and relapse of mandibular anterior alignment – first premolar extraction cases treated by traditional edgewise orthodontics. Am J Orthod 80 (4) 349-364. 6. Graber TM (1963) The ”three M’s”: Muscles, mal- formation, and malocclusion. Am J Orthod 49 (6). 7. Pepicelli A, Woods M, Briggs C (2005) The mandibular muscles and their importance in orthodontics: A contem- porary review. Am J Orthod 128 (6). 8. Sackett DL (1986) The science of the art of clinical management. Craniofacial growth series 237-51.
