Possibly no area of orthodontics has generated more controversy or pendulum swings of opinion than the topic of extractions. The father of orthodontics, Edward Angle1 was fond of saying that the best orthodontic outcomes required a, “full complement of teeth”. However in his own text2 he declared that extractions were appropriate if “the jaws are small and the angles of inclination would be too great” and “placing the teeth in the line of occlusion would result in marked dental and labial prominence”. The 1950’s through the 70’s was a transitional time in orthodontics as treatment methods evolved just as the baby boomers grew into adolescence. Proffit3 tracked the extraction trends and the rate zoomed from 10% of all orthodontic patients in 1953 to 76% by 1968 then trended back down to 28% by 1994. Part of the increase was due to the work of Dr. Begg from Australia who studied stone-age skulls and theorized that their lack of dental crowding was due to the teeth wearing down from a coarse diet thus creating space. Charles Tweed4 was recognized as the greatest clinical orthodontist of his time. He believed Angle’s methods of nonextraction to be unsatisfactory by creating many distorted facial profiles and resulting in unstable alignments of the teeth.
It really became controversial in the 80’s and 90’s as a general dentist named Witzig5 declared that extractions “ruined the face” , caused TMJ issues and a host of other evils. This spawned weekend courses in orthodontics for general dentists. This enterprise continues to confuse the public with elaborate certificates from the “International Association of Orthodontics” which is not a specialty organization but is convoluted to sound like one. His unfounded claims were that orthodontics could be accomplished with functional appliances to grow jaws. The functional appliance portion of this claim will be tackled in a later episode. This nonextraction philosophy was based on case reports and opinion and was not backed up by research with academic rigor. The upside was that it stimulated a scientific backlash from the orthodontic profession to investigate these claims. Witzig and his ilk were long on opinion but short on paying attention to a couple millennia of scientific method. Let’s see what well done research from major university orthodontic programs found when investigating Witzig’s claims:
Behrents6 found that extraction and nonextraction patients ended up with similar profiles after treatment. Similarly, Bishara7 disproved that extractions damaged profiles. He stated, “when based on proper diagnostic criteria, the posttreatment changes in the facial profile were perceived as favorable in both the extraction and nonextraction” patients. Basciftci8 put it most bluntly. “The simple statement that extraction means a more retrusive or dished-in profile seems to be unacceptable. It seems that a more thorough assessment and investigation including pretreatment extent of crowding and factors related to anchorage, soft tissue thickness, and strain should be carried out.” Another claim is that nonextraction or expansion treatment gives a wider more pleasing smile. This was disproved by Kim and Gianelly9 who found that, “The results indicate that arch width is not decreased at a constant arch depth because of extraction treatment, and smile esthetics are the same in both groups of patients.”
And finally, Johnston10 in a study about TMJ health found that there were no significant differences between the extraction and nonextraction samples. “The present data therefore fail to support the popular notion that "premolar extraction causes 'TMJ'.” Johnston was particularly harsh in his criticisms of the unfounded and unscientific approach used by the opponents of nonextraction in the don’t confuse me with facts camp. He conducted numerous studies at the University of Michigan targeted at their claims which were precise in design and repeatedly disproved the nonextraction crowd in the areas of facial esthetics and TMJ health. The reason that extraction cases result in favourable outcomes is that there were sound clinical reasons for doing the extractions in the first place. Then there are the periodontal (gum) considerations. Yared11 determined that angling the mandibular incisors outward increased the severity and the amount of recession. This is a significant disadvantage for nonextraction patients with crowded mandibular incisors. One article I found did call into question one long held belief about extractions. Shah12 in a literature review found that extractions only marginally helped with relapse. There has been quite a bit of research over the years suggesting that expanding the arch form outwards beyond the natural canine width would be less stable.
So where are we as far as my application of extractions in the practice of orthodontics? What is abundantly clear from the research is that extractions do not have a dire effect on facial esthetics, smile esthetics or function of the jaw joint. I could have cited numerous other studies with similar outcomes. Despite my defense of the suitability of extractions in certain situations, I strive to minimize extractions whenever possible by timing treatment appropriately and expanding the arches when the facial anatomy allows it. The science tells us that extraction is a valid tool in orthodontic treatment. The art is in how to apply that tool with my 25 years of experience in dentistry and orthodontics. I believe that too often in healthcare we define the problem and come up with a solution without first defining the desired outcome. Got a pain? Here’s a pill when what you really want is health. Patients familiar with my methods know that I often speak about objectives before deciding on a solution. No patient is going to choose a goal of thin receding gums, teeth that protrude outwards and lips so protrusive that they have difficulty closing them. Yet that may be the outcome if the goal is stated as nonextraction treatment. That is a method and it is inappropriate to consider as a goal. Ultimately you the patient and I the orthodontist desire the same goals: a beautiful healthy smile within an attractive balanced face. And to achieve that worthy goal, in a limited number of patients, extractions can be helpful.
Note AJODO in the citations is the American Journal of Orthodontics and Dentofacial Orthopedics.
Angle EH. Art in relation to orthodontia. Proc Am Soc Orthod. 1902
Angle EH. Malocclusion of the teeth. 7th ed. Philadelphia. SS White Manufacturing. 1907
Proffit WR. Forty-year review of extraction frequency at a university orthodontic clinic. Angle Orthodontist. 1994; 64 (6) 407-414.
Vaden and Merrifield. Charles H Tweed (1895-1970). AJODO. 1999. 115(3) 333-334.
Witzig J W, Spahl T J. The clinical management of basic maxillofacial orthodpaedic appliances. Littleton, Mass.: PSG Publishing Co Inc, 1987.
Behrents. Long-term profile changes in extraction and nonextraction patients AJODO. 2005. 128(4):450-7.
Bishara. Profile changes in patients treated with and without extractions: assessments by lay people. AJODO 1997. 112(6):639-44.
Basciftci. Effects of extraction and nonextraction treatment on class I and class II subjects. Angle Orthod. 2003 73(1):36-42.
Kim and Gianelly. Extraction vs Nonextraction: Arch widths and smile esthetics. Angle Orthod. 2003. 73(4):354-8.
Johnston. The functional impact of extraction and nonextraction treatments: a long-term comparison in patients with "borderline," equally susceptible Class II malocclusions. AJODO. 1994. 105(5):444-449.
Yared KFG, Zenobio EG, Pacheco W. Periodontal status of mandibular central incisors after orthodontic proclination in adults. AJODO. 2006; 130 (1): 6.e1-6.e8.
Shah. Postretention changes in mandibular crowding: a review of the literature AJODO 2003. 124 (3) 298-308.