Creative Adjuncts for Clear Aligners Part 2 Intrusion, Rotation, and Extrusion

S. JAY BOWMAN, DMD, MSD FRANK CELENZA, DDS JOHN SPARAGA, DMD MOSCHOS A. PAPADOPOULOS, DDS, DMD KENJI OJIMA, DDS JAMES CHENG-YI LIN, DDS

art 1 in this series of articles (JCO, February however, the application of adjuncts is still indi- P2015) described a number of adjuncts for im- cated in some cases. proving the reliability of Class II treatment with clear aligners. This month, we will demonstrate Intrusion how to perform certain difficult tooth movements with aligners. Part 3 will conclude the series with Intrusion of selected teeth33 or dental seg- a discussion of extraction and interdisciplinary ments,34 as needed in patients with deep overbites, treatment. has been regarded as challenging to perform with One of the most frustrating aspects of clear- clear aligners. In fixed-appliance treatment, mini- aligner treatment has been the unpredictability of screws have been used to assist not only in intru- tooth movements such as dental extrusion, resolu- sion of single posterior teeth for subsequent pros- tion of rotations, and correction of deep overbites. thetic restorations,35 but in mass intrusion to help For example, Chisari and colleagues reported that close anterior open bites and correct deep over- only 57% of the programmed movement of a sin- bites.22,36,37 It seems logical to extend the applica- gle incisor was actually achieved over an eight- tion of skeletal anchorage into the realm of clear week experimental period.31 Kravitz and col- aligners. leagues found only a mean 41% accuracy.32 As Overeruption of teeth with no opponents is treatment progresses, this lag in tooth movement commonly seen in mutilated dentitions. Intrusion can be compounded, resulting in a “tracking error” of a hypererupted tooth is one way to provide suf- that is usually first noticed as an “air gap” between ficient clearance for prosthetic replacement. Mini- the incisal edges of the incisors and the aligner screws are ideally suited to such a task, since a trays. This situation may spread to other teeth, variety of forces (elastic chain, coil springs, or until the trays no longer fit snugly or the intended elastics) can be applied to predictably guide the tooth movement is adversely affected. Newer plas- programmed intrusion without affecting adjacent tic materials, more accurate digital scans, new teeth, even when using clear aligners (Fig. 8).37,38 attachment designs, and better programming strat- Intrusion of multiple teeth to correct deep egies for treatment planning (including the neces- overbites has been acknowledged as a more chal- sity of overcorrection) have improved the predict- lenging and less predictable aspect of clear-align- ability of outcomes. As we discussed in Part 1, er treatment.34 The importance of resolving deep

162 © 2015 JCO, Inc. JCO/MARCH 2015 Dr. Bowman is a Contributing Editor of the Journal of Clinical Orthodontics; an Adjunct Associate Professor, St. Louis University, St. Louis; a straight-wire instructor, University of Michigan, Ann Arbor, MI; an Assistant Clinical Professor, Case Western Reserve University, Cleveland; a Visiting Clinical Lecturer, Seton Hill University, Greensburg, PA; and in the private practice of orthodontics at 1314 W. Milham Ave., Portage, MI 49024; Drs. Celenza, Sparaga, and Ojima are in the private practice of orthodontics in New York City; Anchorage, AK; and Tokyo, respectively. Dr. Papadopoulos is Professor and Program Director, Department of Orthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece. Dr. Lin is Clinical Assistant Professor, Department of Orthodontics and Pediatric Dentistry, School of Dentistry, National Defense Medical University, Taipei, Taiwan, and in the private practice of orthodontics and implantology in Taipei. Dr. Bowman is inventor of the Clear Collection pliers and Aligner Chewies. E-mail him at [email protected]. Dr. Bowman

overbites has become more apparent in recent A years with the increasing percentage of adult orthodontic patients—especially those with re- stricted anterior function, resulting in severe enam- el attrition of both the incisal edges and the labial and lingual tooth surfaces. Recent improvements in aligner programming have been designed to assist in leveling the curve of Spee with incisor intrusion and premolar or molar extrusion.39 These include biteplanes molded into the aligner trays behind the upper B anterior teeth and bonded attachments used to deliver extrusive forces to the premolars. Since miniscrew anchorage has been highly dependable in correcting deep bites and “gummy smiles”, it has inevitably been applied to similar treatments with clear aligners (Fig. 9).36-38 C Rotation and Extrusion Fig. 8 Molar intrusion supported by miniscrew Dental rotations and extrusion of anterior anchorage and elastics. A. Adult patient with missing lower right first molar and overerupted teeth seem to be the least predictable aligner move- upper second premolar, initially treated with ments. Kravitz and colleagues found that extrusion chain elastic from miniscrew to bonded button was the least accurate tooth movement in aligner on premolar. B. During later Invisalign phase, treatment, at 29.6% effectiveness.32 Reasons for intramaxillary triangle elastics worn from mini- these difficulties, along with strategies to improve screw to bonded buttons on aligners, ensuring 40 proper tray seating and consistent leveling of oc- rotation control, have been proposed by Nicozisis clusal plane. C. Resulting slight overcorrection and Humber.41 We have incorporated several of provided sufficient clearance for implant in 14 their common themes in the following suggestions: weeks of treatment.

VOLUME XLIX NUMBER 3 163 Creative Adjuncts for Clear Aligners

B Fig. 9 Deep-bite treatment with anterior intrusion. A. Adult male patient with mutilated dentition and deep overbite associated with significant anterior wear before treatment. B. Miniscrews inserted between roots of upper lateral incisors and canines for anchorage of intrusion elastics (continued on next page).

164 JCO/MARCH 2015 Bowman, Celenza, Sparaga, Papadopoulos, Ojima, and Lin

D Fig. 9 (cont.) C. Elastic hook formed by placing circular extrusion in facial aligner surface with Hilliard Thermoplier Hook-Forming Pliers,§ then notching half of plastic extrusion with cutting tool. D. Improve- ment in overbite after 22 months of treatment and 35 pairs of aligners.

§Registered trademark of Dentsply Raintree Essix Glenroe, Sarasota, FL; www.essix.com.

VOLUME XLIX NUMBER 3 165 Creative Adjuncts for Clear Aligners

1. To open sufficient space adjacent to the affected tooth, program a visible opening of .25- .5mm into the aligner treatment and/or use inter- proximal reduction. 2. Design appropriate bonded attachments to elic- it rotational and/or extrusive forces.9,42,43 3. Program overcorrection into the aligners to ac- count for the flexibility of the plastic. 4. Use detailing pliers such as Clear Collection’s The Vertical*** and The Horizontal*** to accen- tuate rotational or extrusive couples. 5. Supplement treatment with bonded buttons and elastics or even fixed appliances before or after aligner therapy. 6. Due to the inherent risk of rotational or vertical relapse, discuss the need for supracrestal fiberot- omy (Edwards procedure44) and long-term fixed retention as part of informed consent.

The failure of upper lateral incisors to track properly, commonly seen with Class II, division 2 malocclusions, is especially disconcerting. In some instances, the central incisors would benefit from intrusion while the lateral incisors require extrusion and rotation. Combining selective intrusion, extrusion, root torque, and rotation of anterior teeth requires more than just casual approval of a tech- nician’s programmed treatment plan. Fig. 10 Chewies§ tray seater positioned at “air Failure to address the arch-length discrep- gap” between incisal edge and aligner. ancy before initiating any movement of the lateral incisors is likely to result in disappointment. If extrusion is attempted with insufficient adjacent in place, the patient bites down repeatedly on the space, iatrogenic intrusion may occur as the tooth soft Chewies, each the size of a cotton roll, for is inadvertently “squeezed” apically. Space open- several minutes a day to help seat the aligners, ing also increases the tooth-surface area for the especially as each new pair is started. Chewies are plastic to contact—an important consideration also prescribed when an air gap develops at the with a small, blade-shaped lateral incisor. The ad- incisal edges. In that case, the Chewie should be dition of bonded attachments on the lingual or positioned directly over the affected region to fo- facial surfaces or both should be considered to cus the chewing forces, with the patient holding increase the contact surface area and produce ex- the device solidly between the teeth for 10-15 sec- trusive and/or rotational forces. If tracking is still onds, releasing, and repeating for about five min- lagging behind, other adjuncts can be considered. utes twice a day. Aligner Chewies§ are one of the earliest methods developed to overcome poor tracking or “aligner lag” (Fig. 10).45 Like sequential aligners ***Clear Collection, Hu-Friedy Manufacturing Co., Chicago, IL; www.hu-friedy.com. themselves, these simple devices were based on §Trademark of Dentsply Raintree Essix Glenroe, Sarasota, FL; the concept of the tooth positioner.46 With the trays www.essix.com.

166 JCO/MARCH 2015 Bowman, Celenza, Sparaga, Papadopoulos, Ojima, and Lin

B Fig. 11 “Bootstrap” elastics used to extrude lagging teeth for proper tray seating. A. Elastics stretched from buttons bonded near gingival margin on lingual surfaces of affected teeth to hooks created in facial aligner surface by notching with Tear Drop*** plier. B. Elastics in place in patient with lagging upper lateral incisors (colored elastics worn in occlusal view for demonstration purposes).

Even with the best planning for clear-aligner Open-Bite Treatment biomechanics, aligner lag or tracking error of specific teeth can still occur, often as a result of less- Passive posterior intrusion is a common issue than-ideal patient compliance with aligner wear. in clear-aligner treatment. Posterior plastic can be The application of adjunct elastics may assist with removed to permit spontaneous settling or eruption the extrusion of selected teeth into the aligner of the posterior teeth into occlusion, and forced trays. “Bootstrap” elastics are attached to bonded eruption can also be applied with intermaxillary buttons on the facial, lingual, or both surfaces of elastics (Fig. 13). the lagging tooth at the gingival margin.47 An Clever methods for using clear aligners to orthodontic elastic is stretched across the incisal improve the closure of anterior open bites by intru- surface of the seated aligner to the button, thus sion of posterior teeth have been proposed by extruding or pulling the tooth into the tray. The Boyd39 and Dayan.48 The underlying concept is to gingival margin of the aligner plastic must be cut harness the aligners’ propensity to produce an to avoid the buttons, so that the tray can seat com- iatrogenic posterior open bite simply as a result of pletely. Alternatively, to avoid the need for a button holding plastic between the teeth for extended pe- on the facial side of the tooth, elastic hooks can be riods of time.1,2,49,50 One such strategy involves cut into the aligner tray (Fig. 11). Bootstrap elastics sequential intrusion of specific posterior teeth may prevent or at least delay the need to interrupt while maintaining or extruding the anterior teeth, a series of aligners for the fabrication of refinement thus creating a deeper curve of Spee.48 Using trays (Fig. 12). Chewies to exert intrusive forces on targeted pos-

VOLUME XLIX NUMBER 3 167 Creative Adjuncts for Clear Aligners

C Fig. 12 Maxillary retraction and anterior torque control supported by elastics. A. 12-year-old female patient before treatment with Invisalign TEEN* and Class II elastics. B. After 20 months, due to progressively wors- ening upper left lateral incisor tracking, bonded button and bootstrap elastic added to extrude lateral incisor into aligner tray. C. Patient after completion of treatment, six months later, showing improved smile line.

168 JCO/MARCH 2015 Bowman, Celenza, Sparaga, Papadopoulos, Ojima, and Lin

D Fig. 13 Forced posterior eruption supported by elastics. A. Young adult patient with anterior open bite and reverse smile line before treatment with clear aligners. B. Development of posterior open bite during aligner treatment. C. Buttons added for attachment of posterior rectangular intermaxillary elastics to assist refinement aligners in seating occlusion. D. Patient after 24 months of treatment; addressing curve of Wil- son could have improved these results.

A B C Fig. 14 Extrusion supported by elastics. A. Adult patient with poor tracking of aligner trays in anterior region. B. Buttons bonded to lingual surface of upper left lateral incisor and facial surface of lower left ca- nine for attachment of intermaxillary elastics during refinement stage. C. Patient after 10 months of treatment.

*Registered trademark of Align Technology, Inc., Santa Clara, CA; www.aligntech.com.

VOLUME XLIX NUMBER 3 169 Creative Adjuncts for Clear Aligners

B Fig. 15 Posterior intrusion supported by miniscrew anchorage and elastics. A. Adult female patient with frank anterior open bite treated using Dayan open-bite protocol48 combined with six miniscrew implants (two each on buccal and palatal sides of posterior maxillary alveolus, two in buccal alveolus of posterior mandible). “Sling” elastics worn from palatal to buccal maxillary miniscrews, across occlusal surfaces of aligners, to support intrusion. In lower arch, teardrop notches placed at lingual gingival margin of aligners mesial and distal to first molars; elastics worn from lingual notches to buccal miniscrews, across occlusal surfaces of aligners, to support mandibular vertical control. B. Maxillary left palatal miniscrew relocated mesially; metal and esthetic attachments bonded in upper and lower arches for intermaxillary elastics (continued on next page).

170 JCO/MARCH 2015 Bowman, Celenza, Sparaga, Papadopoulos, Ojima, and Lin

terior teeth can improve the predictability of this tially produce spontaneous mandibular autorota- method. tion (Fig. 15).47 The addition of miniscrew anchorage to sup- Although there is seldom a need to extrude port biomechanics involving elastic forces for the anterior teeth during the correction of anterior extrusion of anterior or posterior teeth is another open bites,51 the combination of clear aligners with logical extension of their application to clear-align- miniscrew anchorage for such treatment has been er treatment (Fig. 14). An alternative type of boot- described by Lin and colleagues.36,52 strap mechanism employs miniscrews to improve the reliability of posterior intrusion and poten- (TO BE CONTINUED)

D Fig. 15 (cont.) C. Rectangular intermaxillary elastics worn after sequential posterior intrusion to assist in seating occlusion. D. After 26 months of treatment, patient in refinement stage.

VOLUME XLIX NUMBER 3 171 Creative Adjuncts for Clear Aligners

REFERENCES

1. Boyd, R.L.; Miller, R.J.; and Vlaskalic, V.: The Invisalign sys- with Invisalign, J. Clin. Orthod. 48:348-358, 2014. tem in adult orthodontics: Mild crowding and space closure 39. Boyd, R.: How successful is Invisalign for treatment of ante- cases, J. Clin. Orthod. 34:203-212, 2000. rior open bite and deep overbite? lecture, AAO annual session, 2. Vlaskalic, V. and Boyd, R.: Orthodontic treatment of a mildly Philadelphia, May 5, 2013. crowded malocclusion using Invisalign system, Austral. 40. Nicozisis, J.L.: Tripping the plastic fantastic, Orthod. Prod., Orthod. J. 17:41-46, 2002. Nov. 2013, pp. 28-34. 9. Boyd, R.L.: Complex orthodontic treatment using a new proto- 41. Humber, P.: Rotating canines using the Invisalign system, col for the Invisalign appliance, J. Clin Orthod. 42:525-547, Aesth. Dent. Today 7:30-34, 2013. 2007. 42. Kuo, E. and Duong, T.: Invisalign attachments: Materials, in 22. Bowman, S.J.: Thinking outside the box with miniscrews, in The Invisalign System, ed. O.C. Tuncay, Quintessence, Microimplants as Temporary Anchorage in Orthodontics, ed. London, 2007, pp. 91-98. J.A. McNamara Jr. and K.A. Ribbens, Craniofacial Growth 43. Boyd, R.L. and Vlaskalic, V.: Three-dimensional diagnosis Series, University of Michigan, Ann Arbor, 45:327-390, 2008. and orthodontic treatment of complex malocclusion with the 31. Chisari, J.R.; McGorray, S.P.; Nair, M.; and Wheeler, T.T.: Invisalign appliance, Semin. Orthod. 7:274-293, 2001. Variables affecting orthodontic tooth movement with clear 44. Edwards, J.G.: A surgical procedure to eliminate rotational aligners, Am. J. Orthod. 145(4 suppl):S82-91, 2014. relapse, Am. J. Orthod. 57:35-46, 1970. 32. Kravitz, N.D.; Kusnoto, B.; Begole, E.; Obrez, A.; and Agran, 45. Tuncay, O.: The iatrogenic crowding caused by aligner length/ B.: How well does Invisalign work? A prospective clinical arch length discrepancy, Clinical Reports & Techniques study evaluating the efficacy of tooth movement with (Align Technology), Fall 2005, pp. 3-5. Invisalign, Am. J. Orthod. 135:27-35, 2009. 46. Kesling, H.D.: The philosophy of tooth positioning appliance, 33. Turatti, G.; Womack, R.; and Bracco, P.: Incisor intrusion with Am. J. Orthod. 31:297-304, 1945. Invisalign treatment of an adult periodontal patient, J. Clin. 47. Giancotti, A. and Ronchin, M.: Pre-restorative treatment with Orthod. 40:171-174, 2006. the Invisalign system, J. Clin. Orthod. 40:679-682, 2006. 34. Krieger, E.; Seiferth, J.; Marinello, I.; Jung, B.A.; Wriedt, S.; 48. Dayan, W.: Techniques for posterior intrusion in the correc- Jacobs, C.; and Wehrbein, H.: Invisalign treatment in the ante- tion of anterior open bite with Invisalign, Align Technology rior region: Were the predicted tooth movements achieved? J. white paper, 2010. Orofac. Orthop. 73:365-376, 2012. 49. Womack, W.R.; Ahn, J.H.; Ammari, Z.; and Castillo, A.: A 35. Lin, J.C.Y.; Liou, E.J.W.; and Yeh, C.L.: Intrusion of over- new approach to correction of crowding, Am. J. Orthod. erupted maxillary molars with miniscrew anchorage, J. Clin. 122:310-316, 2002. Orthod. 40:378-383, 2006. 50. Schupp, W.; Haubrich, J.; and Neumann, I.: Treatment of ante- 36. Lin, J.C.Y.; Yeh, C.L.; Liou, E.J.W.; and Bowman, S.J.: rior open bite with the Invisalign system, J. Clin. Orthod. Treatment of skeletal-origin gummy smiles with miniscrew 44:501-507, 2010. anchorage, J. Clin. Orthod. 42:285-296, 2008. 51. Guarneri, M.P.; Oliverio, T.; Silvestre, I.; Lombardo, L.; and 37. Lin, J.C.Y.; Liou, E.J.W.; and Bowman, S.J.: Simultaneous re- Siciliani, G.: Open bite treatment using clear aligners, Angle duction in vertical dimension and gummy smile using mini- Orthod. 83:913-919, 2013. screw anchorage, J. Clin. Orthod. 44:157-170, 2010. 52. Lin, J.C.Y.; Tsai, S.J.; Liou, E.J.W.; and Bowman, S.J.: 38. Giancotti, A.; Germano, F.; Muzzi, F.; and Greco, M.: A mini- Treatment of challenging malocclusions with Invisalign and screw-supported intrusion auxiliary for open-bite treatment miniscrew anchorage, J. Clin. Orthod. 48:23-36, 2014.

172 JCO/MARCH 2015