• If a patient has just one of the above problems with severity it is likely best to extract four bicuspids. • If a patient has two of these problems in modera-tion the case could be treated either non-extrac-tion or with four bicuspid extractions. We need to look at the comprehensive variables to assess what would be best in these situations. These are among the most difficult cases to diagnose in Orthodon-tics. Here is the tradeoff: If a case with two of these variables is treated non-extraction it will look best upon completion but will be quite vulnerable to stability problems in retention. If bicuspids are extracted the result will still be lovely although lack some smile width but will be more stable in retention long-term. • If a patient has three of these problems, you must extract bicuspids. Not to extract bicuspids is destined to long treatment times with poor results and retention. These cases will not be aesthetic, stable, or periodontally healthy. • If a patient has all four reasons listed above, extraction of four bicuspids will be inadequate. These patients will require multiple extraction of four bicuspids AND two upper molars (either the upper 6's or the upper 7's). When there is/are missing bicuspids or impacted bicuspids it often is best on prosthetic replacement or retrieval of the impacted bicuspids unless there are also enough of the listed reasons to extract bicuspids (Fig. 14). Or let’s say this a different way: In any case where there are missing, impacted, or damaged bicuspids, ask yourself how you would treat the case if these teeth were not missing or compromised. If the answer is a definitive non-extraction, it is VERY likely the best plan is to open space for this/these missing tooth/teeth and plan on prosthetic replacement. And one final note: A bicuspid should never be removed in a quadrant that has an impacted tooth until it is 100% certain the impacted tooth can be retrieved. A lot of time and stress can be reduced in these cases if the impacted tooth is extracted. When this happens it is most often best to also extract the contra-lateral tooth for aesthetic and symmetry reasons. "whEn ThERE iS/ARE MiSSing BiCuSPiDS oR iMPACTED BiCuSPiDS iT ofTEn iS BEST on PRoSThETiC REPlACEMEnT oR RETRiEvAl of ThE iMPACTED BiCuSPiDS unlESS ThERE ARE AlSo Enough of ThE liSTED REASonS To EXTRACT BiCuSPiDS (fig. 14). oR lET’S SAY ThiS A DiffEREnT wAY: in AnY CASE whERE ThERE ARE MiSSing, iMPACTED, oR DAMAgED BiCuSPiD ASk YouRSElf how You woulD TREAT ThE CASE if ThESE TEETh wERE noT MiSSing oR CoMPRoMiSED. " bicuspids to extract and the appropriate mechanics to control how the extraction spaces are closed. It is fallacy to assume a profile necessarily will be changed just because four bicuspids are removed. Elegant orthodontic treatment permits command of how the extraction spaces are managed. REfEREnCES 1. O'Connor, Bran MP. "Contemporary trends in orthodontic prac-tice: a national survey." American Journal of Orthodontics and Dentofacial Orthopedics 103.2 (1993): 163-170. 2. Kesling, Peter C. "System for automatically preventing overtipping and/or overuprighting in the Begg Technique." U.S. Patent No. 4,664,626. 12 May 1987. 3. Begg, Percy R. "Stone Age man's dentition: with reference to anatomically correct occlusion, the etiology of malocclusion, and a technique for its treatment." American Journal of Orthodontics and Dentofacial Orthopedics 40.4 (1954): 298-312. 4. Little, Robert M. "Stability and relapse of mandibular anterior alignment: University of Washington studies." Seminars in Orthodontics. Vol. 5. No. 3. WB Saunders, 1999. 5. Engelke W, Jung K, Knosel M. (2011) “Intra-oral compartment pressures: biofunctional model and experimental measurements under different conditions of posture.” Clin Oral Invest 15: 165-176. 6. Baer, Paul N., and Melvin L. Morris. Textbook of Periodontics. Lippincott, 1977. 7. Othman, Siti, and Nigel Harradine. "Tooth size discrepancies in an orthodontic population." The Angle Orthodontist 77.4 (2007): 668-674. 8. Angle, Edward H. "Classification of malocclusion." Dental Cosmos 41 (1899): 248-264. In this article we discussed the rational for extraction of four bicuspids. While Orthodontic Specialists tend to extract nearly ¼ of their cases many GP’s lack the education, confidence, and skill to manage an extrac-tion case. Treating a case that truly should be extracted produces an un-aesthetic, un-stable, and periodontally compromised result. When there are sufficient combina-tions of lower crowding, skeletally open bite, Cl II, or protusion the best, easiest and shortest treatment may require extracting teeth. In part 2 of this 3 part article we will discuss which SuMMARY 22 Spring 2018 JAOS
Journal of the American Orthodontic Society Spring 2018: Page 22
