One Phase vs. Two Phase Orthodontic Treatment — Which is Best?

by Randy Lang, DDS, D. Ortho

On Saturday nights, when my wife and I are standing in line at the local movie theatre waiting to buy our tickets, or more importantly to buy our popcorn, like all conscientious orthodontists I naturally look around at kids’ teeth. And as time goes by I am surprised to find that I am seeing more and more six, seven and eight-year-olds wearing braces.

Most of these young kids appear to have a Class II malocclusion and the dentist or orthodontist has obviously begun an early “phase-one” treatment in the early mixed dentition. I say “phase-one” because the orthodontic literature clearly states that almost all of these young kids will require a second “phase-two” stage of treatment at age 11 or 12 to complete the case, after the permanent dentition has erupted.

Thus the treatment plan would be an early “phase-one” treatment for one to two years, followed by a one to three year “retention phase” wearing a retainer while waiting for the primary teeth to fall out, and then a final “phase-two” treatment consisting of conventional full bonding for 1.5 to two years to finish the case. The total early treatment + retention + later treatment can easily total five to six years.

And there is nothing wrong with this multi-phase treatment approach to Class II malocclusions. In fact, almost every orthodontic text book advises an early phase of orthodontic treatment for those very severe protrusions, where the maxillary incisors are out so far that they come around the corner about five seconds before you see the rest of the child’s face. Early partial retraction of the incisors is done in these cases for safety reasons. Current literature, however, does not support the routine two-phase treatment approach for all Class II cases.

Until recently, there was little in the way of hypothesis-tested studies to render a scientific evidence-based judgement concerning the merits of two-stage treatment for Class II malocclusions. In the past few years, however, a number of articles have appeared in prestigious orthodontic journals commenting on the value of two-phased treatment:

Dr. Fedon Livieratos and Dr. Lysle Johnston1 in a paper titled, “A comparison of one-stage and two-stage nonextraction treatment in matched Class II samples” concluded that an early phase of functional appliance treatment prior to fixed appliance therapy was of no measurable benefit whatsoever. They also stated that there was little or no objective support for those who claim that early functional appliance treatment somehow reduces both the need for extractions and the length and complexity of the subsequent fixed appliance phase of treatment.

Dr. Jay Bowman,2 in his paper titled “One-stage versus two-stage treatment — Are two really necessary?” stated that “Unfortunately, today’s trends are to treat earlier and often. The resulting array of techniques runs the gamut from the refuted (arch development for mixed dentition) to the patentedly ridiculous (braces for baby teeth). Can in utero treatment be far off? Most disturbing is that this trend is occurring without support in the referred literature.”

Dr. James Ferguson3 concluded that, “Two phase orthodontic treatment takes longer, costs more and delivers the same treatment result as one-phase, traditional orthodontic treatment. I think in many instances it is merely a means to capture patients for orthodontic treatment and prevent them from going elsewhere.”

Dr. Anthony Gianelly,4 the professor and chairman of the Department of Orthodontics at Boston University, points out that “there are few, if any, benefits that are unique to and dependent on earlier treatment. For more than 90 percent of patients, all treatment goals can be accomplished in one phase of treatment started in the very late mixed dentition.”

Dr. Robert Moyers5 warns that “there is no assurance that the results of early treatment will be sustained and that two-phased treatment will always lengthen overall treatment time. Early treatment not only may do some damage or prolong therapy, it may exhaust the child’s spirit of cooperation and compliance.”

The Proceedings of the 1997 Workshop Discussion on Early Treatment6 cautioned that “in the discussion, the participants pointed to the need to guard against the potential iatrogenic problems that may occur with early treatment such as dilaceration of roots, decalcification under bands left for too long, impaction of maxillary second molars from distalizing first molars, and patient ‘burnout’.”

Dr. C. Tulloch,7 in a recent study at the University of North Carolina, concluded that “for children with moderate to severe Class II problems, early treatment followed by later comprehensive treatment does not produce major differences in jaw relationship or dental occlusion compared with later one-stage treatment.”

So, does “two phase” treatment of Class II malocclusions work? You bet. Does it end up taking longer and costing more? Almost always. Is the treatment result better than one phase? No way. Should parents be informed of these facts and given a choice of treatment (i.e. informed consent)? I should hope so. Are those who routinely use a longer “two phase” treatment to correct all their Class II malocclusions ever going to re-examine their treatment strategies if this longer and costlier treatment approach is not evidence-based? I don’t know. I guess the only way to find out is to keep checking the kids in the popcorn line at the movies.OH


1.Livieratos, F., Johnston L. A comparison of one-stage and two-stage nonextraction alternatives in matched Class II samples. AJODO 1995; 108:118-131.

2.Bowman, J. One-stage versus two-stage treatment: Are two really necessary? AJODO 1998; 113: 111-116.

3.Ferguson, J. Comment on two-phase treatment. AJODO 1996; 110: 1 4A-15A.

4.Gianelly, A. One-phase versus two-phase treatment. AJODO 1995; 108:556-559.

5.Moyers, R. Handbook of orthodontics, 4th ed. Chicago, Year Book Medical Publishers; 1988. p. 346-7, 433-4.

6.Bishara, S., Justus, R., and Graber, TM. Proceedings of the workshop discussions on early treatment. AJOIDO 1998; 113: 5-6.

7.Tulloch, C., Phillips, C. and Proffit, W. Benefit of early Class II treatment: Progress report of a two-phase randomized clinical trial. AJODO 1998; 113: 62-71.