CASE REPORT an Alternative Method for Correcting Unilateral Posterior Crossbite with Functional Shift in an Adolescent Patient

CASE REPORT An Alternative Method for Correcting Unilateral Posterior Crossbite with Functional Shift in an Adolescent Patient

NANDAKUMAR JANAKIRAMAN, BDS, MDS, MDSc SARAH ADABI, DDS RAVINDRA NANDA, BDS, MS, PhD FLAVIO URIBE, DDS, MDSc

nilateral posterior crossbite This functional shift causes the metry is needed to prevent per- U(UPC) is frequently observed mandibular midline to deviate to- manent establishment of the de- in children, with an incidence ward the crossbite side, so that a formity, which can affect the ranging from 8.7% to 23.3%.1 An unilateral Class II molar relation- TMJ and masticatory system.2,4 associated functional shift of the ship is observed.2 The morpholo- Therefore, UPC correction is usu- mandible appears in 80% of the gy of the mandible is symmetri- ally recommended during the de- patients with UPC, due to occlusal cal, but the mandible is positioned ciduous or mixed dentition.5 This interferences that produce asym- asymmetrically, at least in a article documents an alternative metrical mandibular displacement younger patient with UPC.3 method of managing UPC with during closure from centric rela- Early interceptive treatment functional shift in a young ado- tion to maximum intercuspation.2 of mandibular positional asym- lescent.

Dr. Janakiraman Dr. Adabi Dr. Nanda Dr. Uribe

Dr. Janakiraman is an Assistant Professor and Dr. Adabi is a Research Fellow, Division of Orthodontics, Department of Craniofacial Sciences, University of Connecticut School of Dental Medicine, 263 Farmington Ave., Farmington, CT 06030. Dr. Nanda is an Associate Editor of the Journal of Clinical Orthodontics and the UConn Orthodontic Alumni Endowed Chair, Division of Orthodontics, and Professor and Head, Department of Craniofacial Sciences, University of Connecticut School of Dental Medicine. Dr. Uribe is a Contributing Editor of the Journal of Clinical Orthodontics and an Associate Professor, Postgraduate Program Director, and Charles J. Burstone Endowed Professor, Division of Orthodontics, Department of Craniofacial Sciences, University of Connecticut School of Dental Medicine. E-mail Dr. Janakiraman at [email protected].

Fig. 1 A. 14-year-old female patient with facial asymmetry, canted intercommissural line at rest, unilateral posterior crossbite, and non- A coincident midlines before treatment (continued on next page).

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C D Fig. 1 (cont.) B. Intermolar width measured at mesiobuccal cusps of upper first molars and buccal grooves of lower first molars, showing transverse discrepancy of .5mm. C. Minor transverse deficiency on crossbite (right) side. D. Slightly excessive buccal inclination of upper first molars and lingual inclination of lower first molars.

Diagnosis and crossbite side and the upper mid- nine. Clicking of the left TMJ Treatment Plan line was shifted by 1mm to the was observed on opening, with no left. The arch-length-tooth-size associated pain and a reciprocal A 14-year-old female pre- discrepancy was 8mm in the click—a finding consistent with sented with the chief complaint of maxilla and 2mm in the mandi- disc dislocation with reduction. crooked upper teeth. Clinical ex- ble; the lower left first premolar Transverse cast measure- amination indicated a slight facial was abnormally wide (10mm). ments showed .5mm of arch dis- asymmetry: the chin point was The lateral cephalogram crepancy at the mesiobuccal deviated to the right of the facial showed two mandibular lower cusps of the upper first molars midline by about 2mm, and there borders, and the panoramic x-ray and the buccal grooves of the low- was a canted intercommissural revealed slightly dissimilar con- er first molars (Fig. 1B). The cor- line (Fig. 1A). End-on Class II dylar morphology. During closure onal view indicated a slightly ex- molar and canine relationships to maximum intercuspation, the cessive buccal inclination of the were present on the right side, mandible shifted to the right side, upper first molars and lingual in- where the teeth from lateral inci- indicating a centric relation-cen- clination of the lower first molars, sor to second premolar were in tric occlusion (CR-CO) discrep- however, suggesting dental com- crossbite in maximum intercuspa- ancy caused by occlusal interfer- pensation for the underlying skel- tion. Because of this UPC, the ences from the lingually displaced etal transverse deficiency on the lower midline was shifted to the upper right lateral incisor and ca- crossbite side (Fig. 1C,D).

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Fig. 2 Acrylic inclined plane cemented to lower anterior teeth.

B Fig. 3 A. Patient after three months of treatment, with lower inclined plane removed. B. Four months after removal of lower inclined plane, showing resolution of centric relation-centric occlusion discrepancy.

The orthodontic treatment Treatment Progress arch. After three months of treat- plan was to create optimal condi- ment, the lower anterior inclined tions for normal growth by re- The upper arch was bonded plane was removed (Fig. 3A). At solving the UPC. Treatment goals with .022" preadjusted applianc- that point, the patient had a slight were to eliminate the functional es, and .016" nickel titanium arch- anterior open bite. shift by removing the occlusal in- wires were placed for initial level- The patient was scheduled terferences from the upper right ing and alignment. A piece of for a recall visit after one month lateral incisor and canine, using a acrylic covering the incisal third to evaluate her occlusion, but did lower inclined plane and upper of the mandibular teeth from ca- not report for four months. We fixed appliances. After resolution nine to canine, with an inclined then observed that CR was coin- of the CR-CO discrepancy, the plane on the right side to remove cident with CO, and there was no occlusion would be reassessed for occlusal interferences, was af- functional shift (Fig. 3B). Signif- further treatment. fixed with glass ionomer cement* icant improvement was also noted (Fig. 2). Four weeks later, an in the lower midline, which was *GC Fuji Ortho LC, Alsip, IL; www. .016" × .022" nickel titanium coincident with the facial mid- gcamerica.com. archwire was placed in the upper line. There was still a slight bilat-

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TABLE 1 CEPHALOMETRIC ANALYSIS

Pre- Post- Norm treatment Treatment Change SNA 82° 78.0° 78.5° +0.5° SNB 80° 76.0° 76.0° 0.0° ANB 2° 2.0° 2.5° +0.5° SN-GoGn 32° 41.0° 43.0° +2.0° IMPA 90° 90.0° 95.0° +5.0° U1-SN 102° 101.0° 107.0° +6.0° U1-NA 4mm 9.0mm 7.0mm –2.0mm L1-NB 4mm 8.0mm 9.5mm +1.5mm Upper lip-E line –4mm –3.5mm –5.0mm –1.5mm Lower lip-E line –2mm –1.5mm –1.5mm 0.0mm eral transverse discrepancy, as treatment, the upper arch was UPC was corrected. The patient evidenced by a Class I molar re- aligned, and the maxillary and and her parents were entirely sat- lationship on the right and an end- mandibular midlines were coin- isfied with her facial appearance, on Class II molar relationship on cident with the facial midline. In- profile, and smile (Fig. 4A). the left. terproximal stripping was then Cephalometric analysis in- With the CR-CO discrep- performed to recontour the lower dicated an unchanged sagittal ancy resolved, nonextraction left first premolar. Finishing position of the maxilla and man- treatment was planned. This bends were placed in .016" × dible and an increase in SN-MP would involve expanding the den- .022" beta titanium archwires, (Table 1). Superimposition of tal arches by 2mm with arch- and the patient was instructed to pre- and post-treatment tracings wires, flaring the upper incisors wear seating elastics. confirmed a slight downward by 2mm, shifting the maxillary The patient showed excel- displacement of the mandible midline to the right by 1mm, and lent compliance in wearing the (Fig. 4B). The maxillary region- interproximally stripping the elastics and maintaining good al superimposition showed flar- maxillary teeth to create 2mm of oral hygiene. After a total 23 ing of the incisors and no molar space for the left canine. An ad- months of treatment, the fixed ap- movement, while the mandibular ditional 1.5mm of interproximal pliances were removed, an upper superimposition demonstrated stripping was planned to reduce Hawley retainer was delivered, mesial movement and extrusion the mesiodistal width of the low- and a lower 3-3 lingual retainer of the molars as well as flaring er left first premolar. was bonded. of the incisors. The lower arch was bonded At the end of treatment, the and an .016" nickel titanium arch- patient still exhibited disc dis Treatment Results wire was placed. In the upper location with reduction; she was arch, after the interproximal All treatment objectives therefore referred to a TMJ spe- stripping was performed, a push- were achieved: the well-balanced cialist for further treatment. Fif- coil spring was attached from the profile was maintained, the facial teen months later, the results re- left first premolar to the left lat- symmetry was improved, coinci- mained stable (Fig. 5). eral incisor to shift the midline to dent midlines and CR-CO were (continued on p. 531) the right. Fifteen months into established, and the functional

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A B Fig. 4 A. Patient after 23 months of treatment. B. Superimposition of pre- and post-treatment cephalometric tracings.

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Fig. 5 Patient 15 months after treatment.

Discussion pared to the control group, but no rical archform on the crossbite significant difference in maxil- side, but not in a patient with an UPC can be caused by a lary intermolar widths.2 Ferro expanded archform. A UPC pa- skeletal disproportion between and colleagues noted three differ- tient with a constricted archform the maxilla and mandible, a dis- ent archforms—symmetrical, ex- on the crossbite side may benefit crepancy of the transverse dental panded, and constricted—on the from unilateral expansion, which arch width, or a functional shift.6 crossbite sides in a sample of is now possible using mini- Langberg and colleagues found a young adolescents with UPC.7 implant anchorage. 4mm greater mandibular arch According to these authors, max- Most of the UPC treatment width at the first molars in a illary expansion may be indicated protocols reported in the litera- group of adults with UPC com- in a UPC patient with a symmet- ture have been designed to in-

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crease transverse maxillary arch placement.9,10 Although a recent 2. Langberg, B.J.; Arai, K.; and Miner, R.M.: Transverse skeletal and dental width during the deciduous or epidemiological study of young asymmetry in adults with unilateral lin- mixed dentition, regardless of the adolescents by Farella and col- gual posterior crossbite, Am. J. Orthod. etiology. Devices such as the leagues found no association be- 127:6-15, 2005. 3. Pinto, A.S.; Buschang, P.H.; Throck Quad Helix,** rapid palatal ex- tween disc displacement and morton, G.S.; and Chen, P.: Morpho panders, removable expansion posterior crossbite, indicating logical and positional asymmetries of plates, and transpalatal arches adaptation of the TMJs,11 a 20- young children with functional unilat- 8 eral posterior crossbite, Am. J. Orthod. have all been found effective. year longitudinal study of un- 120:513-520, 2001. Here, however, we have described treated orthodontic patients by 4. Marshall, S.D.; Southard, K.A.; and an alternative treatment approach Egermark and colleagues noted Southard, T.E.: Early transverse treatment, Sem. Orthod. 11:130-139, 2005. using a lower anterior inclined a significant correlation between 5. De Boer, M. and Steenks, M.H.: plane. The rationale is to remove a functional UPC and later TMJ Functional unilateral posterior cross- the occlusal interferences that disorders.12 Based on these find- bite: Orthodontic and functional as- pects, J. Oral Rehab. 24:614-623, 1997. lead to a CR-CO discrepancy, ings, it may still be prudent to 6. Thilander, B. and Bjerklin, K.: Pos thus avoiding forced movement of perform early intervention in a terior crossbite and temporomandibular the jaw to one side. In the case UPC patient to correct the func- disorders (TMDs): Need for orthodontic treatment? Eur. J. Orthod. 34;667- shown here, after use of the in- tional shift and allow normal, 673, 2012. clined plane and upper fixed ap- symmetrical growth of the max- 7. Ferro, F.; Spinella, P.; and Lama, N.: pliances, the CR-CO discrepancy illa and mandible. Delaying Transverse maxillary arch form and mandibular asymmetry in patients with due to functional shift was re- treatment until the permanent posterior unilateral crossbite, Am. J. solved. In addition, the minor dentition may well increase treat- Orthod. 140: 828-838, 2011. transverse discrepancy between ment complexity and length.6 8. Petrén, S.; Bondemark, L.; and Söder feldt, B.: A systematic review concern- the maxillary and mandibular ing early orthodontic treatment of uni- arches was corrected with dental lateral posterior crossbite, Angle Conclusion expansion from the archwires. Orthod. 73:588-596, 2003. 9. Pullinger, A.G. and Seligman, D.A.: Early interceptive correc- This article highlights the Quantification and validation of predic- tion of UPC is recommended be- importance of accurate diagnosis tive values of occlusal variables in tem- cause an untreated malocclusion in determining the etiology of a poromandibular disorders using a mul- tifactorial analysis, J. Prosth. Dent. carried from the deciduous to the UPC. A lower inclined plane can 83:66-75, 2000. permanent dentition may affect help correct the crossbite in an 10. Marklund, S. and Wänman, A.: Risk long-term maxillomandibular adolescent patient by eliminating factors associated with incidence and 5,8 persistence of signs and symptoms of growth and development. A dental interferences. Concomitant temporomandibular disorders, Acta malpositioned mandible can lead maxillary expansion is recom- Odontol. Scand. 68:289-299, 2010. to asymmetrical development of mended only if there is a trans- 11. Farella, M.; Michelotti, A.; Iodice, G.; Milani, S.; and Martina, R.: Unilateral orofacial structures and conse- verse maxillary discrepancy. posterior crossbite is not associated quent remodeling of the TMJs.8 with TMJ clicking in young adoles- Indeed, several reports have REFERENCES cents, J. Dent. Res. 86:137-141, 2007. 12. Egermark, I.; Magnusson, T.; and shown a linear association be- 1. Iodice, G.; Danzi, G.; Cimino, R.; Carlsson, G.E.: A 20-year follow-up of tween UPC and TMJ disc dis- Paduano, S.; and Michelotti, A.: Asso signs and symptoms of temporoman- ciation between posterior crossbite, dibular disorders and malocclusions in masticatory muscle pain, and disc dis- subjects with and without orthodontic **Rocky Mountain Orthodontics, Denver, placement: A systematic review, Eur. J. treatment in childhood, Angle Orthod. CO; www.rmortho.com. Orthod. 35:737-744, 2013. 73:109-115, 2003.

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