Patients with cleft lip and palate (CLP) usually

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, 602-739, South Korea; E-mail: 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

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 13 92.86 7 63.64 Female 1 7.14 4 36.36 Total 14 100 11 100 Age (years) 0Y12 0 0 2 18.18 12Y18 0 0 4 36.36 Over 18 14 100 5 45.45 Mean 21.7 16.3 Amount 0Y5 mm 2 14.29 0 0 of advancement of a point 5Y10 mm 12 85.71 5 54.55 10Y15 mm 0 0 3 27.27 15Y20 mm 0 0 2 18.18 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

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

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) j9.47 2.98 j10.60 4.14 0.4332 j3.05 3.52 0.23 3.94 0.038* j4.59 4.13 j2.03 3.79 0.124 A to FH (mm) 36.67 4.76 33.54 6.47 0.1763 38.89 5.52 35.68 8.48 0.264 38.19 5.33 35.42 8.17 0.317 B to N-per (mm) j3.16 5.57 j9.48 7.39 0.0228* j8.86 5.03 j11.26 7.65 0.353 j7.89 6.28 j10.81 6.21 0.258 B to FH (mm) 81.97 5.16 77.67 9.45 0.1593 82.56 3.47 80.86 10.38 0.571 82.00 4.27 80.19 9.27 0.523 PP to FH (-) 0.26 3.54 1.95 3.53 0.2470 3.14 4.52 j1.33 4.03 0.017* 2.56 4.01 j1.53 5.64 0.045* ANS to FH (mm) 28.13 3.72 26.35 5.36 0.3386 30.32 4.74 27.95 7.22 0.334 30.08 4.62 27.28 7.43 0.259 PNS to FH (mm) 27.87 4.64 24.66 5.68 0.1330 27.64 3.67 28.72 5.44 0.560 27.88 4.13 28.29 5.13 0.824 U1 to N-per (mm) j4.44 4.16 j12.31 6.28 0.0010 1 1.14 4.65 0.53 5.56 0.769 0.86 5.08 0.25 4.13 0.751 U1 to FH (mm) 58.59 4.58 53.51 8.26 0.0624 60.89 4.61 56.81 9.79 0.180 60.56 4.36 57.86 8.71 0.322 Nose tip 24.63 2.28 20.73 3.30 0.0019 1 27.60 2.31 26.63 3.96 0.452 27.22 3.09 25.80 2.91 0.253 to N-per (mm) Nose tip to FH (mm) 23.08 3.43 20.63 5.05 0.1625 21.78 3.70 18.50 7.19 0.152 22.22 3.74 19.15 6.62 0.156 Nasolabial angle (-) 70.40 14.57 88.30 13.81 0.0048* 89.31 11.02 103.51 13.18 0.007 1 82.96 15.06 96.85 10.46 0.016* UL to N-per (mm) 13.71 4.05 8.31 3.91 0.0027 1 17.29 4.61 18.63 4.42 0.471 16.04 4.51 16.96 3.71 0.590 The differences between two groups were tested by independent t test. *P G 0.05. 1 P G 0.01. 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

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) 6.42 1.69 10.79 5.06 0.0059 1 j1.54 1.99 j2.26 2.82 0.422 DA to FH (mm) 2.22 2.35 2.14 3.64 0.9483 j0.70 1.54 j0.26 1.85 0.462 DB to N-per (mm) j5.69 4.34 j1.78 4.58 0.040* 0.97 3.58 0.46 2.92 0.569 DB to FH (mm) 0.59 2.83 3.19 3.34 0.046* j0.56 2.05 j0.67 3.88 0.931 DPP to FH () 2.88 3.59 j3.28 3.57 0.0003 2 j0.58 1.59 j0.19 2.39 0.977 DANS to FH (mm) 2.19 2.22 1.60 3.81 0.6311 j0.24 1.67 j0.67 2.04 0.306 DPNS to FH (mm) j0.23 2.20 4.06 2.79 0.0003 2 0.23 1.39 j0.43 2.86 0.011* DU1 to N-per (mm) 5.58 1.78 12.84 6.17 0.0003 2 j0.28 2.52 j0.28 3.13 0.999 DU1 to FH (mm) 2.30 2.38 3.30 3.59 0.4110 j0.33 1.29 1.06 2.70 0.030* DNose tip to N per (mm) 2.97 1.16 5.91 3.84 0.0123* j0.38 1.99 j0.84 2.12 0.349 DNose tip to FH (mm) j1.30 1.39 j2.14 2.88 0.3494 0.44 1.47 0.66 2.10 0.801 DNasolabial angle () 18.91 10.81 15.22 15.41 0.4887 j0.38 1.99 j0.84 2.12 0.349 DUL to N-per (mm) 3.58 2.99 10.32 5.63 0.0008 2 0.44 1.47 0.66 2.10 0.801 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 0.05. 1 P G 0.01. 2 P G 0.001. 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

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. 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