Patients with cleft lip and palate (CLP) usually

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1 Comparison of Treatment Outcome and Stability Between Distraction Osteogenesis and LeFort I Osteotomy in Cleft Patients With Maxillary Hypoplasia Seung-Hak Baek, DDS, MSD, PhD,* Jin-Kyung Lee, DDS, 1 Jong-Ho Lee, DDS, MSD, PhD, 2 Myung-Jin Kim, DDS, MSD, PhD, 2 Jong-Ryoul Kim, DDS, MSD, PhD Seoul and Pusan, South Korea The purpose of this study was to compare treatment outcome and relapse between maxillary advancement surgery with LeFort I osteotomy and maxillary distraction osteogenesis in patients with cleft lip and palate with maxillary hypoplasia. The sample consisted of a maxillary advancement surgery with LeFort I osteotomy group (group 1, N = 14, mean age, 21.7 years) and a maxillary distraction osteogenesis group (group 2, N = 11, mean age, 16.3 years). Lateral cephalograms were taken and traced at presurgery (T0), postsurgery (T1), and postretention (T2). Nine hard and four soft tissue cephalometric variables were measured. Differences in measurements at each stage, treatment outcome (T1-T0), and relapse (T2-T1) were compared between groups with independent t test. Because the amount of surgical movement could affect the amount of relapse, a difference in relapse between two groups was compared by analysis of covariance with the amount of surgical movement as a covariant. Although the amounts of forward movements of A point (P G 0.01), upper incisor (P G 0.001), and upper lip (P G 0.001) during T1-T0 were greater in group 2, there were no significant differences in the amounts of relapse (T2-T1) between the two groups. During T1-T0, counterclockwise rotation of the palatal plane was From the *Department of Orthodontics, Institute of Dental Research, School of Dentistry, Seoul National University; the 1 Department of Orthodontics, Seoul National University Dental Hospital; the 2 Department of Oral and maxillofacial Surgery, School of Dentistry, Seoul National University, Seoul; and the Department of Oral and maxillofacial Surgery, College of Dentistry, Pusan National University, Pusan, South Korea. Address correspondence and reprint requests to Jong-Ryoul Kim, DDS, MSD, PhD, Department of Oral and Maxillofacial Surgery, College of Dentistry, Pusan National University, Ami-dong, Seo-Ku, Pusan, , South Korea; jorkim@pusan.ac.kr observed in group 2 as a result of downward movement of posterior nasal spine (PNS) at T1, whereas group 1 had clockwise rotation of palatal plane at T1 because of downward movement of anterior nasal spine (ANS). The amounts of relapse (T2-T1) in vertical movements of PNS and upper incisor were significantly different between the two groups (P G 0.05). The amount of required maxillary advancement, vector control of palatal plane, and vertical position of upper incisor would be important factors when planning a surgical treatment in patients with cleft lip and palate with midface hypoplasia. Key Words: Maxillary distraction osteogenesis, Le- Fort I maxillary advancement, cleft patients Patients with cleft lip and palate (CLP) usually present with collapsed maxillary dental arch and impaired forward growth of the maxilla as a result of scar tissue from the early surgical repair of CLP. 1 In many cases, these problems require orthodontic treatment combined with orthognathic surgical procedures such as LeFort I osteotomy or distraction osteogenesis. 2 There have been numerous studies about longterm stability and/or relapse of maxillary advancement surgery with LeFort I osteotomy (MAL). 3Y15 The amount of relapse for MAL in noncleft patients with maxillary hypoplasia is known to be 10%. 16 However, compared with noncleft patients, patients with CLP showed much higher rates of relapse from 25% to 50%. 4,17Y23 Problems associated with long-term stability of MAL in patients with CLP have been attributed to retraction of the scar tissue, tightness of the upper lip, interference with the nasal septum, inadequate mobilization of the bony segment, and thin and 1209

2 THE JOURNAL OF CRANIOFACIAL SURGERY / VOLUME 18, NUMBER 5 September 2007 fragile bony structures of the lateral piriform wall and zygoma base for rigid fixation. 8,24 The application of distraction osteogenesis in the maxillofacial region is gaining popularity. Maxillary distraction osteogenesis (MDO) has become an alternative option for treatment of maxillary hypoplasia in patients with CLP 25 and can be used in growing patients. 26,27 However, it remains controversial whether MDO has better outcomes than conventional MAL, particularly in patients with CLP. The purpose of this study was to compare treatment outcomes and relapse between MAL and MDO in patients with CLP with maxillary hypoplasia and to suggest guidelines for establishing a surgical treatment plan for patients with CLP. MATERIALS AND METHODS Sample Twenty-five patients with CLP with midface hypoplasia were divided into two groups: group 1 treated with MAL and rigid internal fixation (N = 14; mean age, 21.7 years) and group 2 treated with MDO using the RED system (KLS Martin, Tuttlingen, Germany) (N = 11; mean age, 16.3 years) (Table 1). Cephalometric Measurements Presurgery (T0, 1 month before MAL or MDO), postsurgery (T1, 1 month after MAL or end of the consolidation period of MDO), and postretention (T2, debonding stage in MAL or 8 months after MDO) lateral cephalograms were taken at centric occlusion and natural head position. Fourteen cephalometric landmarks and two reference lines are listed in Figure 1. The Frankfurt horizontal (FH) plane and N perpendicular line were used as horizontal and vertical reference lines, respectively. Nine hard and four soft tissue cephalometric variables are sown in Figures 2 and 3. For evaluating the anteroposterior and vertical movement of the maxilla and mandible, points A and B were used, respectively (Fig 2). To estimate rotation of the maxilla, vertical movements of anterior nasal spine (ANS) and posterior nasal spine (PNS) and palatal plane angle (the angle between palatal plane and FH plane) were measured (Fig 2). For appraising the anteroposterior and vertical movements of the upper central incisor, the incisal edge of the upper central incisor was used as a landmark (Fig 2). The anteroposterior and vertical locations of the upper Table 1. Comparison of the Patients Profile and the Amount of Maxillary Advancement lip and nose and nasolabial angle were evaluated for the soft tissue measurement (Fig 3). The amount of surgical movement with MAL or MDO was determined by subtracting the values of T1 variables from T0 ones. The relapse was calculated as the difference in the variables between T2 and T1. For surgical movement and relapse, (+) value reflect forward movement or clockwise rotation, and (Y) value, backward movement or counterclockwise rotation (Figs 2 and 3). The tracings of lateral cephalograms in T0, T1, and T2 stages were digitized by a digitizer (INTUOS 2 graphic tablet; Wacom Technology Co., Vancouver, Canada) and measured in the units of 0.05and 0.05 mm by V-Ceph (CyberMed, Seoul, Korea). Statistical Analysis Independent t test was used to compare the variables at each stage, surgical movement (T1-T0), and relapse (T2-T) between two groups. Because the amount of surgical movement could affect the amount of relapse, it is needed to standardize the variables that showed significant differences of surgical movement between two groups. Therefore, the difference in relapse between two groups was compared by analysis of covariance with the amount of surgical movement as a covariant. RESULTS Group 1 Group 2 Number Percent Number Percent Gender Male Female Total Age (years) 0Y Y Over Mean Amount 0Y5 mm of advancement of a point 5Y10 mm Y15 mm Y20 mm Group 1 means maxillary advancement with LeFort I osteotomy; group 2, maxillary distraction osteogenesis. Comparison of Hard and Soft Tissue Variables at Presurgery (T0) Between Groups 1 and 2 Although there were no significant differences in the anteroposterior and vertical positions of the 1210

3 DO AND LE FORT I OSTEOTOMY IN CLEFT PATIENTS / Baek et al Fig 1 Cephalometric landmarks and reference lines: 1) S, 2) N, 3) Or, 4) Por, 5) A point, 6) ANS, 7) PNS, 8) U1E, 9) U6MBC, 10) B point, 11) nose tip, 12) Cm, 13) Sn, 14) UL, 15) FH plane, 16) N perpendicular line. U1E, upper incisor edge; U6MBC, mesiobuccal cusp of the upper first molar; Cm, columella; Sn, subnasale; UL, upper lip; FH, Frankfurt horizontal. maxilla between two groups, group 2 showed a tendency that the maxilla was more posteriorly and superiorly located (A to N-perpendicular, A to FH). However, B point of group 1 was positioned significantly more anteriorly than group 2 (B to Fig 3 Soft tissue variables. 1) Nose tip to N-perpendicular line (mm), 2) nose tip to FH plane (mm), 3) UL to N-perpendicular line (mm), 4) nasolabial angle (-). FH, Frankfurt horizontal plane; UL, upper lip. N-perpendicular, P G 0.05). Therefore, group 1 had more prognathic mandible than group 2 (Table 2). As a result of skeletal midface deficiency in group 2, the incisal edge of the upper incisor, upper lip, and nasal tip in group 2 were more posteriorly placed than those in group 1 (U1 to N-perpendicular, P G 0.01; UL to N-perpendicular, P G 0.01; nose tip to N-perpendicular, P G 0.01). In addition, the nasolabial Fig 2 Hard tissue variables. (A) 1) A to N-perpendicular line (mm), 2) A to FH plane (mm), 3) B to N-perpendicular line (mm), 4) B to FH plane (mm); (B) 5) PP to FH plane (-), 6) ANS to FH plane (mm), 7) PNS to FH plane (mm), 8) U1 to N perpendicular line (mm), 9) U1 to FH plane (mm). FH, Frankfurt horizontal plane; PP, palatal plane, line connecting ANS and PNS; U1, upper central incisor. 1211

4 THE JOURNAL OF CRANIOFACIAL SURGERY / VOLUME 18, NUMBER 5 September 2007 Table 2. Comparison of Variables at T0, T1, and T2 Stage T0 T1 T2 Group 1 (n = 14) Group 2 (n = 11) Group 1 (n = 14) Group 2 (n = 11) Group 1 (n = 14) Group 2 (n = 11) Variables Mean SD Mean SD Significance Mean SD Mean SD Significance Mean SD Mean SD Significance A to N-per (mm) j j j * j j A to FH (mm) B to N-per (mm) j j * j j j j B to FH (mm) PP to FH (-) j * j * ANS to FH (mm) PNS to FH (mm) U1 to N-per (mm) j j U1 to FH (mm) Nose tip to N-per (mm) Nose tip to FH (mm) Nasolabial angle (-) * * UL to N-per (mm) The differences between two groups were tested by independent t test. *P G P G T0, presurgery (1 month before MAL or MDO); T1, postsurgery (1 month after MAL or end of consolidation period of MDO); T2, postretention (debonding stage in MAL or 8 months after MDO); group 1, maxillary advancement with LeFort I osteotomy (MAL); Group 2, maxillary distraction osteogenesis (MDO); SD, standard deviation; N-per, N-perpendicular; FH, Frankfurt horizontal plane; PP, palatal plane; + value of PP to FH, clockwise rotation of PP; Y value of PP, counterclockwise rotation of PP; U1, upper central incisor; UL, upper lip. angle in group 2 was significantly larger than group 1 (P G 0.05). Comparison of Hard and Soft Tissue Variables at Postsurgery (T1) and Postretention (T2) Between Groups 1 and 2 After the operation (T1), point A of group 2 was positioned significantly more anteriorly than group 1 (P G 0.05) because the amount of maxillary advancement was greater in MDO than MAL. There was significant counterclockwise rotation of the palatal plane (PP to FH plane, P G 0.05) in group 2 compared with group 1, likely as a result of downward movement of PNS during MDO. Therefore, the clinician must be aware of vector control during MDO. There was more increase of nasolabial angle (P G 0.05) in group 2 than in group 1 (Table 2). After retention (T2), group 2 preserved counterclockwise rotation of the palatal plane (PP to FH plane, P G 0.05) and increased value of nasolabial angle (P G 0.05). Comparison of the Amount of Surgical Movements (T1-T0) Between Groups 1 and 2 Although the amount of forward movement of point A (DA to N-perpendicular) in group 2 was significantly larger than in group 1 (P G 0.01), there was no significant difference in vertical movement of point A (DA to FH) between the two groups (Table 3). In group 1, downward movement of ANS resulted in clockwise rotation of the palatal plane. However, in group 2, there was greater downward movement of PNS than of ANS, which caused counterclockwise rotation of the palatal plane (DPP to FH, P G 0.001). Therefore, there was significantly more downward movement of point B (DB to FH, P G 0.05) in group 2 than in group 1. Forward movement of the upper lip (DUL to N-perpendicular) was significantly greater (P G 0.001) in group 2 because of greater forward movement of point A (DA to N-perpendicular, P G 0.01) and upper incisor (DU1 to N-perpendicular, P G 0.001). Although both groups showed upward movements of the nose tip, vertical movement of the nose tip (Dnose tip to FH) was not significantly different. However, the amount of forward movement of the nose tip (Dnose tip to N-perpendicular) was significantly greater in group 2 than in group 1 (P G 0.05). Comparison of the Amount of Relapse (T2-T1) Between Groups 1 and 2 Although point A relapsed backward and upward at T2, there was no significant difference in the amount 1212

5 DO AND LE FORT I OSTEOTOMY IN CLEFT PATIENTS / Baek et al Table 3. Comparison of Surgical Movement and Relapse Stage T1-T0 (Surgical Movement) T2-T1 (Relapse) Group 1 (n = 14) Group 2 (n = 11) Group 1 (n = 14) Group 2 (n = 11) Variables Mean SD Mean SD Significance Mean SD Mean SD Significance DA to N-per (mm) j j DA to FH (mm) j j DB to N-per (mm) j j * DB to FH (mm) * j j DPP to FH () j j j DANS to FH (mm) j j DPNS to FH (mm) j j * DU1 to N-per (mm) j j DU1 to FH (mm) j * DNose tip to N per (mm) * j j DNose tip to FH (mm) j j DNasolabial angle () j j DUL to N-per (mm) For surgical movement, independent t test was used. Difference in relapse between two groups was compared by analysis of covariance using amount of surgical movement as a covariant. *P G P G P G T0, presurgery (1 month before MAL or MDO); T1, postsurgery (1 month after MAL or end of consolidation period of MDO); T2, postretention (debonding stage in MAL or 8 months after MDO); group 1, maxillary advancement with LeFort I osteotomy (MAL); group 2, maxillary distraction osteogenesis (MDO); SD, standard deviation; N-per, N-perpendicular; FH, Frankfurt horizontal plane; PP, palatal plane; + value of PP to FH, clockwise rotation of PP; Y value of PP, counterclockwise rotation of PP; U1, upper central incisor; UL, upper lip. of relapse between two groups. The amounts of anteroposterior and vertical relapses of point B between two groups were clinically insignificant and had no statistically significant difference. There was no significant difference in palatal plane rotation between the two groups (Table 3). The amounts of vertical relapse of PNS displayed significant difference between groups 1 and 2 (DPNS to FH, P G 0.05). This was likely the result of the opposite direction of PNS movement during operation. There was almost no vertical relapse of the upper incisor in group 1. However, group 2 had 1-mm downward movement of the upper incisor (DU1 to FH, P G 0.05). DISCUSSION Age MAL is usually done after the end of the mandibular growth to prevent relapse of the anterior crossbite. However, MDO can be performed in growing patients to minimize facial deformity. In this study, mean age of group 1 was 21.7 years and all patients were older than 18 years of age. In group 2, mean age was 16.3 years, younger compared with group 1, and 45.5% of the patients were under 18 years of age. If MDO is performed during the growth period, relapse can occur as a result of residual mandibular growth, and therefore another MAL or MDO can be needed after the growth period has ended (Table 1). There are many obstacles to do a randomized, controlled trial that can objectively compare the advantages and disadvantages of MAL and MDO. Therefore, as the next best way, this study used a retrospective research to compare two methods. Amount of Surgical Movement Saelen et al 28 stated that stability was well maintained in patients with CLP after advancing the maxilla up to 6 mm using MAL. In this study, the average amount of forward movement of point A in group 1 was 6.42 mm, similar to Saelen et al s study. 28 Movement direction of point A was forward and downward with clockwise rotation of the palatal plane (approximately 3) as a result of a downward shift of ANS in group 1 (Tables 2 and 3). Saelen et al 28 reported that in patients with CLP requiring more than 6 mm of maxillary advancement, simultaneous maxillary advancement and mandibular set back surgery could be a treatment of choice. Although there were no significant differences in the anteroposterior position of point A between two groups at T0, point B of group 1 was significantly positioned anteriorly (P G 0.05, Table 2). Therefore, group 1, except one patient, had 1213

6 THE JOURNAL OF CRANIOFACIAL SURGERY / VOLUME 18, NUMBER 5 September 2007 mandibular setback surgery (average amount, 5.69 mm) to compromise the limited amount of forward movement of maxilla. However, in group 2, the average amount of anterior movement of point A was significantly larger (10.79 mm) than group 1 (P G 0.01, Table 3) and the palatal plane was rotated approximately 3 counterclockwise as a result of downward shift of PNS. Two reasons why mandibular set back surgery was not done in group 2 are as follows; first, there were younger patients with incomplete mandibular growth (45.5%); second, the amount of anteroposterior discrepancy was enough to be corrected by maxillary DO only. In the study using the RED system (KLS Martin), Figueroa et al 29 stated that the palatal plane usually moves downward in a parallel manner. In this study, the palatal plane rotated approximately 3- counterclockwise in group 2 because PNS has shifted farther downward than ANS. It appears that there were vector control problems in MDO during our early experience. Overall, downward movement of PNS in group 2 induced clockwise rotation of the mandible through the wedge effect and consequently it shifted point B to a backward and downward direction. As a result of the significant difference in the amount of forward movement of the maxilla in group 2, the amounts of forward movement of the upper incisor (P G 0.001), nose tip (P G 0.01), and upper lip (P G 0.001) were also significantly greater in group 2 than group 1 (Table 3). Stability/Relapse/Overcorrection The average amount of relapse of maxillary advancement in group 1 was 1.54 mm, which is approximately 24% of the surgical movement. This is higher value compared with the average amount of relapse in non-clp patient (10%) during MAL. 4,7,11,17,19,30 The average amount of relapse of maxillary advancement in group 2 was 2.26 mm, which is approximately 21% of the amount of maxillary advancement. Although the amount of maxillary advancement was greater in group 2, there was no significant difference in relapse between two groups. Therefore, the amount of anteroposterior overcorrection during surgery can be regarded as similar for MDO or MAL. Other measurements that showed differences in surgical movement also had no significant differences in the amount of relapse between two groups, except for the palatal plane and vertical position of the upper incisor (Tables 2 and 3). Significant downward movement of the upper incisor during retention in group 2 was possibly the result of the longer postoperative orthodontic treatment period and the use of intermaxillary elastics during that period in young patients in cases of MDO. CONCLUSION Although the amount of maxillary advancement was greater in MDO than MAL, there was no significant difference in the amount of anteroposterior relapse between the two groups. Directions of palatal plane rotation at T1 and T2 were opposite between MDO and MAL. Therefore, the results of this study suggest that the amount of required maxillary advancement, vector control of the palatal plane, and vertical position of the upper incisor would be important factors when planning a surgical treatment in patients with CLP with midface hypoplasia. REFERENCES 1. Ross RB. Treatment variables affecting facial growth in complete unilateral cleft lip and palate. Cleft Palate J 1987;24:5Y77 2. Adlam DM, Yau CK, Banks P. A retrospective study of the stability of midface osteotomies in cleft lip and palate patients. Br J Oral Maxillofac Surg 1989;27:265Y Araujo A, Schendel SA, Wolford LM, et al. Total maxillary advancement with and without bone grafting. J Oral Surg 1978;36:849Y Drommer R, Luhr HG. The stabilization of osteomised maxillary segments with Luhr mini-plates in secondary cleft surgery. J Maxillofac Surg 1981;9:166Y Garrison BT, Lapp TH, Bussard DA. The stability of Le Fort I maxillary osteotomies in patients with simultaneous alveolar cleft bone grafts. J Oral Maxillofac Surg 1987;45:761Y Posnick JC, Ewing MP. Skeletal stability after Le Fort I maxillary advancement in patients with unilateral cleft lip and palate. Plast Reconstr Surg 1990;85:706Y Louis PJ, Waite PD, Austin RB. Long-term skeletal stability after rigid fixation of Le Fort I osteotomies with advancements. Int J Oral Maxillofac Surg 1993;22:82Y86 8. Posnick JC, Dagys AP. Skeletal stability and relapse patterns after Le Fort I maxillary osteotomy fixed with miniplates: the unilateral cleft lip and palate deformity. Plast Reconstr Surg 1994;94:924Y Posnick JC, Taylor M. Skeletal stability and relapse patterns after Le Fort I osteotomy using miniplate fixation in patients with isolated cleft palate. Plast Reconstr Surg 1994;94:51Y Cheung LK, Samman N, Hui E, et al. The 3-dimensional stability of maxillary osteotomies in cleft palate patients with residual alveolar clefts. Br J Oral Maxillofac Surg 1994;32: 6Y Proffit WR, Turvey TA, Phillips C. Orthognathic surgery: a hierarchy of stability. Int J Adult Orthodon Orthognath Surg 1996;11:191Y Van Sickels JE, Richardson DA. Stability of orthognathic surgery: a review of rigid fixation. Br J Oral Maxillofac Surg 1996;34:279Y Gurstein KW, Sather AH, An KN, et al. Stability after inferior or anterior maxillary repositioning by Le Fort I osteotomy: a biplanar stereocephalometric study. Int J Adult Orthodon Orthognath Surg 1998;13:131Y

7 DO AND LE FORT I OSTEOTOMY IN CLEFT PATIENTS / Baek et al 14. Heliovaara A, Ranta R, Hukki J, et al. Skeletal stability of Le Fort I osteotomy in patients with isolated cleft palate and bilateral cleft lip and palate. Int J Oral Maxillofac Surg 2002;31:358Y Dowling PA, Espeland L, Sandvik L, et al. LeFort I maxillary advancement: 3-year stability and risk factors for relapse. Am J Orthod Dentofacial Orthop 2005;128:560Y Hoffman GR, Brennan PA. The skeletal stability of one-piece Le Fort 1 osteotomy to advance the maxilla; Part 2. The influence of uncontrollable clinical variables. Br J Oral Maxillofac Surg 2004;42:226Y Kufner J. Four year experience with major maxillary osteotomy for retrusion. J Oral Surg 1971;29:549Y Epker BN, Wolford LM. Middle-third facial osteotomies: their use in the correction of congenital dentofacial and craniofacial deformities. J Oral Surg 1976;34:324Y Champy M. Surgical treatment of midface deformities. Head Neck Surg 1980;2:451Y Eskenazi LB, Schendel SA. An analysis of Le Fort I maxillary advancement in cleft lip and palate patients. Plast Reconstr Surg 1992;90:779Y Hirano A, Suzuki H. Factors related to relapse after Le Fort I maxillary advancement osteotomy in patients with cleft lip and palate. Cleft Palate Craniofac J 2001;38:1Y Baumann A, Sinko K. Importance of soft tissue for skeletal stability in maxillary advancement in patients with cleft lip and palate. Cleft Palate Craniofac J 2003;40:65Y Cheung LK, Chua HD. A meta-analysis of cleft maxillary osteotomy and distraction osteogenesis. Int J Oral Maxillofac Surg 2006;35:14Y Welch TB. Stability in the correction of dentofacial deformities: a comprehensive review. Oral Maxillofac Surg 1989;47: 1142Y Cohen SR, Corrigan M, Wilmot J, et al. Cumulative operative procedures in patients aged 14 years and older with unilateral or bilateral cleft lip and palate. Plast Reconstr Surg 1995;96:267Y Rachmiel A, Aizenbud D, Peled M. Long-term results in maxillary deficiency using intraoral devices. Int J Oral Maxillofac Surg 2005;34:473Y Wang XX, Wang X, Yi B, et al. Internal midface distraction in correction of severe maxillary hypoplasia secondary to cleft lip and palate. Plast Reconstr Surg 2005;116:51Y Saelen R, Tornes K, Halse A. Stability after Le Fort I osteotomy in cleft lip and palate patients. Int J Adult Orthodon Orthognath Surg 1998;13:317Y Figueroa AA, Polley JW, Friede H. et al Long-term skeletal stability after maxillary advancement with distraction osteogenesis using a rigid external distraction device in cleft maxillary deformities. Plast Reconstr Surg 2004;114: 1382Y Carlotti AE Jr, Schendel SA. An analysis of factors influencing stability of surgical advancement of the maxilla by the Le Fort I osteotomy. J Oral Maxillofac Surg 1987;45:924Y