CRANIOMAXILLOFACIAL DEFORMITIES/COSMETIC SURGERY
Le Fort III Distraction Osteogenesis Versus Conventional Le Fort III Osteotomy in Correction of Syndromic Midfacial Hypoplasia: A Systematic Review Humam Saltaji, DDS, MSc,* Mostafa Altalibi, BSc, DMD, GPR,y Michael P. Major, DMD, MSc, FRCD(C),z Muhammed H. Al-Nuaimi, BSc,x Sawsan Tabbaa, DDS, MSc,k Paul W. Major, DDS, MSc, FRCD(C),{ and Carlos Flores-Mir, DDS, DSc, FRCD(C)# Purpose:
It has been debated whether the Le Fort III procedure using distraction osteogenesis (LFIIIDO) reduces the risk of postintervention relapse compared with conventional Le Fort III (LFIII) osteotomy in the correction of syndromic midfacial hypoplasia. Our objective was to evaluate the short- and long-term stability of the bony structures after midfacial advancement using conventional LFIII osteotomy versus LFIII-DO in patients with syndromic midfacial hypoplasia.
Materials and Methods:
We performed a systematic review of the published data. An electronic search of 10 databases was performed from their inception through June 2012. The reference lists of the relevant publications were also reviewed. Studies were considered for inclusion if they were longitudinal clinical studies with follow-up periods of at least 1 year after surgery (LFIII group) or at the end of the consolidation period (LFIII-DO group). Study selection, risk of bias assessment, and data extraction were performed in duplicate. The methodologic and clinical heterogeneity across the studies precluded combining the findings using meta-analyses.
Results:
A total of 57 reports met the initial search criteria, and 12 reports were finally selected. The studies demonstrated a mean midfacial advancement of 8 to 12 mm in the LFIII group and 9 to 16 mm in the LFIII-DO group. For the LFIII group, horizontal short-term follow-up showed a maximal rate of relapse of 8.7 to 11.9% in 2 studies, with 1 study demonstrating a far more severe rate of maximal relapse of 50%. For the LFIII-DO procedure, the horizontal short-term relapse rate was 14.4% in 1 study, with the remainder demonstrating a rate of relapse of less than 10%. Moreover, 3 studies even showed additional advancement without any rate of relapse.
Conclusions: Current evidence suggests that conventional LFIII and LFIII-DO techniques can effectively advance the midface forward in patients with syndromic midfacial hypoplasia and have good to excellent stability, with a mild rate of relapse. However, the LFIII-DO technique appears to achieve a greater amount *PhD Candidate and Resident, Orthodontic Graduate Program,
#Associate Professor and Head, Division of Orthodontics,
University of Alberta Faculty of Medicine and Dentistry School of
University of Alberta Faculty of Medicine and Dentistry School of
Dentistry, Edmonton, AB, Canada.
Dentistry, Edmonton, AB, Canada.
yMSc Resident, University of Alberta Faculty of Medicine and
Conflict of Interest Disclosures: None of the authors reported any
Dentistry School of Dentistry, Edmonton, AB, Canada.
disclosures.
zClinical Assistant Professor, University of Alberta Faculty of
Address correspondence and reprint requests to Dr Saltaji: Ortho-
Medicine and Dentistry School of Dentistry, Edmonton, AB, Canada.
dontic Graduate Program, 5-476, Edmonton Clinic Health Academy,
xDental Student, University of Alberta Faculty of Medicine and Dentistry School of Dentistry, Edmonton, AB, Canada.
University of Alberta Faculty of Medicine and Dentistry School of Dentistry, 11405-87 Ave, Edmonton, AB T6G 1C9 Canada; e-mail:
kAssistant Professor, State University of New York at Buffalo
[email protected]
School of Dental Medicine, Buffalo, NY.
Received September 7 2013
{Professor and Chair, University of Alberta Faculty of Medicine
Accepted September 24 2013
and Dentistry School of Dentistry, and Senior Associate Dean,
Ó 2014 American Association of Oral and Maxillofacial Surgeons
University of Alberta Faculty of Medicine and Dentistry, Edmonton,
0278-2391/13/01232-9$36.00/0
AB, Canada.
http://dx.doi.org/10.1016/j.joms.2013.09.039
959
960
LE FORT III DISTRACTION VERSUS LE FORT III OSTEOTOMY
of advancement with a lower rate of relapse compared with the conventional LFIII technique. Ó 2014 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 72:959-972, 2014 Craniofacial synostosis syndromes (e.g., Crouzon and Apert syndromes) are craniofacial anomalies characterized by the premature fusion of the craniofacial sutures; this results in midface hypoplasia.1 Syndromic midfacial hypoplasia requires orthognathic surgery, which aims to restore the functional and esthetic impairment and to establish proper occlusion and increase airway patency by advancing the midface.2-4 The traditional surgical procedure for correcting midfacial hypoplasia is a Le Fort III (LFIII) osteotomy.3 This technique was first introduced in 19505 and was then revised and modified over time by multiple investigators.6-9 In more recent years, however, a variation of the LFIII procedure came in to use, using distraction osteogenesis (LFIII-DO). This technique was first described in 199510 and has become an apparently effective and reliable technique in the management of syndromic midfacial hypoplasia.11-13 Both conventional LFIII and LFIII-DO surgeries are considered complex techniques, because they require a multidisciplinary team, including a plastic and craniofacial surgeon, ophthalmologist, otolaryngologist, clinical psychologist, speech pathologist, dietician, audiologist, and orthodontist.14,15 Both the surgeon and the orthodontist play key roles in the surgical planning and managing the pre- and postintervention occlusion, oral function, and esthetic appearance. However, the management of syndromic midfacial hypoplasia has been a challenge for the reconstructive team, because the surgical approach has been associated with multiple complications and adverse effects, ranging from mild relapse to blindness and death.16-19 The conventional LFIII osteotomy procedure was reported to be more invasive than the LFIII-DO technique, because the former has usually required the use of bone grafts and has been associated with greater soft tissue tension and higher complication rates than the LFIII-DO technique.20 It has been debated whether the LFIII-DO technique reduces the risk of postintervention relapse, owing to the gradual nature of the approach, which allows progressive bone regeneration and soft tissue adaptation.20,21 To meaningfully evaluate the effectiveness of the interventions, it is important to assess not only the immediate postintervention changes, but also the long-term changes and occurrence of relapse. Therefore, the objectives of the present report were to systematically review the short- and long-term skeletal stability after midfacial advancement between the conventional LFIII osteotomy and the LFIII-DO procedures in patients with midfacial hypoplasia due to craniofacial synostosis syndromes.
Materials and Methods The reporting of the present systematic review was performed in accordance with the PRISMA statement for reporting systematic reviews of health sciences.22
DATA SOURCES AND SEARCHES
Comprehensive searches up to July 10, 2012 were conducted using the following electronic bibliographic databases: PubMed (1966 to July 2012, week 2); MEDLINE (1980 to 2012, week 28); EMBASE (1980 to 2012, week 28); ISI Web of Science (1965 to July 10, 2012); Evidence-Based Medicine (EBM) Reviews–Cochrane Central Register of Controlled Trials (1991 to July 2012); All EBM Reviews, including the Cochrane Database of Systematic Reviews, American College of Physicians (ACP) Journal Club, Database of Abstracts of Reviews of Effects (1991 to July 2012); and HealthSTAR (1966 to July 2012). An update of the search was conducted on March 21, 2013. The search strategy was devised with the help of a health science librarian specializing in the field of dental research. The key words used varied slightly to be tailored to the databases but generally involved ‘‘Le Fort III,’’ ‘‘distraction osteogenesis,’’ ‘‘midfacial advancement,’’ ‘‘craniofacial dysostosis,’’ ‘‘craniosynostosis,’’ ‘‘Apert,’’ ‘‘Crouzon,’’ and ‘‘Pfeiffer.’’ The initial search strategy was designed for PubMed (Table 1) and was then adapted to the other databases. Of the relevant studies finally selected, manual searches were subsequently performed of the references, and, in cases of ambiguity, the authors of the reports were contacted. No restrictions were applied regarding publication year or language. When additional information was needed, efforts were made to contact the authors. Table 1. SEARCH STRATEGY USED IN PUBMED
1. Le Fort III OR Le Fort III OR distraction* osteogenesis OR midface* advancement OR mid-fac* advancement OR midface* osteotomy OR mid-fac* osteotomy 2. Craniofacial dysostosis OR craniosynostosis OR syndrome* OR mid-fac* hypoplasia OR midfac* hypoplasia OR mid-fac* retrusion OR midfac* retrusion OR maxilla* hypoplasia OR cleft OR Apert OR Crouzon OR Pfeiffer 3. #1 and #2 Saltaji et al. Le Fort III Distraction Versus Le Fort III Osteotomy. J Oral Maxillofac Surg 2014.
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SALTAJI ET AL STUDY SELECTION
The appropriate reports to be included fulfilled the following pre-established eligibility criteria: Population: Patients with midfacial hypoplasia due to craniofacial synostosis syndromes (e.g., Apert, Crouzon, Pfeiffer, and Saethre-Chotzen). Only human studies were eligible. No restrictions were applied regarding age or gender. Intervention: Surgical therapy to correct midface hypoplasia with conventional LFIII osteotomy or LFIII-DO. Comparison: Before and after treatment or conventional LFIII versus LFIII-DO or another equivalent intervention. Outcome: Stability of the outcome assessed at least 1 year after treatment. The data were considered shortterm when the follow-up period was less than 3 years and long-term when the follow-up period was at least 3 years. Horizontal and vertical changes in the maxilla and midface were assessed at the end of treatment and at least 1 year after treatment using the following points of interest: A-point, the deepest point on the contour of the alveolar projection; ANS point, anterior nasal spine; SNA angle, angle between the anterior cranial base and A-point; and Or, orbitale. Study Design: Longitudinal clinical studies with follow-up periods of at least 1 year after surgery (LFIII group) or after the end of the consolidation period (LFIII-DO group). Both prospective and retrospective studies, with more than 6 patients per intervention group, were included: randomized controlled trails (RCTs), nonrandomized controlled clinical trials, clinical trials, and case series studies with 6 or more patients. Three reviewers (H.S., M.A., M.E.) independently reviewed the list of titles and abstracts for inclusion. Once potentially adequate abstracts had been selected, the full reports were retrieved in a second final selection process. If the abstract was judged to contain insufficient information for a decision of inclusion or exclusion, the full report was obtained and reviewed before a final decision was made. Any discrepancies in the inclusion of the studies among the reviewers were addressed through discussion until a consensus had been reached. RISK OF BIAS ASSESSMENT
The methodologic quality of the included studies was assessed by 2 reviewers (H.S. and M.A.), and discrepancies were resolved by discussion until a consensus was reached. The studies were assessed according to a checklist of the following methodologic criteria23,24: eligibility criteria, sample size, randomization, blinding
of the outcome assessor, selective reporting, description of intervention details, description of outcome measures, description of withdrawals, description of adverse effects, and adequacy of data analysis. DATA EXTRACTION
The data were extracted for each of the selected studies according to the following outcomes: study design, age at surgery, sample size, diagnosis, follow-up period, latency period, distraction rate, consolidation period, mean movement obtained, and short- and long-term relapses in the horizontal and vertical dimensions. Study demographics such as publication year and country in which the study had been conducted were also collected. Data extraction were performed by the same 2 investigators (H.S. and M.A.), and discrepancies were resolved by discussion until consensus was reached. DATA SYNTHESIS
Pooling of the data to provide an estimate of the effectiveness of the interventions was planned for the studies reporting the same outcome measures. Furthermore, if sufficient trials were identified, subgroup and sensitivity analyses would be conducted. Finally, publication bias was to be assessed using a funnel plot by evaluating the degree of funnel plot asymmetry.25 Case series were planned to be analyzed separately from clinical trials owing to the high risk of publication bias in case series. Statistical heterogeneity across the studies was to be tested and evaluated using the c2 test and the I2 statistic,26 where I2 values greater than 50% indicate considerable heterogeneity. Clinical heterogeneity was evaluated by examining the various characteristics of the finally selected reports, including dis-similarity between the different types of interventions, outcomes, and patients. In the case of insufficient clinically homogeneous trials for any intervention, a qualitative synthesis was planned.
Results STUDY SELECTION
The search returned 1,237 potential records for inclusion, including 775 duplicates. Screening excluded 405 records because of the title and abstract. The remaining 57 full-text reports were retrieved for a more detailed evaluation, of which 10 reports20,27-35 fulfilled the inclusion and exclusion criteria. Additionally, 2 reports3,36 were identified through the reference list search; thus, 12 reports were finally included. The update of the search found no additional eligible reports to be included. A flow diagram of the data search is given
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LE FORT III DISTRACTION VERSUS LE FORT III OSTEOTOMY
in Figure 1. Of the 57 full reports initially selected, 37 were excluded because of an incomplete or no follow-up report of the data,13-15,21,37-69 6 because of an inadequate sample size,52,53,56,70-72 13 because of an incomplete or no cephalometric analysis reported,21,41-45,48,50,73-76 and 2 because Le Fort I osteotomies were included.77,78 The excluded studies and the reasons for their exclusion are listed in Table 2.
RISK OF BIAS ASSESSMENT
Included
Eligibility
Screening
Identification
Of the 12 studies finally selected, 3 were clinical trials20,27,28 and 9 were case series.3,29-36 The methodologic assessment tool portrayed a variance of 42.9 to 67.8% of the total scores. These findings
Relevant records identified through database searching (n=1237)
are summarized in Table 3 and represent moderate methodologic assessment scores.
STUDY CHARACTERISTICS
Of the 12 studies finally selected, 10 had been published between 2005 and 2012, including all the LFIIIDO studies. Eight studies had been conducted in North America,3,20,27,28,31-33,35,36 2 in Italy,28,29 and 1 each in Korea30 and Brazil.34 Conventional LFIII Osteotomy Five studies reporting on the LFIII osteotomy procedure were finally selected: 2 clinical trials20,27 and 3 case series3,35,36; all conducted in North America. The sample sizes ranged from 11 to 25 patients per intervention group, patient age at surgery ranged
Records excluded, duplicates (n=775)
Records screened based on title/abstract (n=462) Records excluded based on title/abstract (n=405) Full text articles retrieved for more detailed evaluation (n=57) Articles excluded based on inclusion-exclusion criteria (n=47) Studies met inclusionexclusion criteria (n=10) Articles identified through other sources (n=2)
Studies included in qualitative analysis, systematic review (n=12)
Studies included in quantitative analysis, metaanalysis (n=0) FIGURE 1. Flow diagram of the published data search according to the PRISMA statement.22 Saltaji et al. Le Fort III Distraction Versus Le Fort III Osteotomy. J Oral Maxillofac Surg 2014.
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SALTAJI ET AL
Table 2. REPORTS NOT SELECTED FROM INITIAL ABSTRACT SELECTION LIST AND REASONS FOR EXCLUSION
Study Liu et al,77 2012 Nout et al,58 2012 Ahmad et al,49 2012 Coeugniet et al,48 2012 Warren et al,72 2012 Oberoi et al,14 2012 Yun et al,78 2011 Meling et al,42 2011 Nakajima et al,39 2011 Ettinger et al,46 2011 Sant’Anna et al,75 2010 Mitsukawa et al,70 2010 Oyama et al,76 2009 Uyama et al,50 2009 Ponniah et al,55 2008 Witherow et al,15 2008 Nishimoto et al,38 2008 Witherow et al,51 2008 Jensen et al,44 2007 Vachiramon et al,52 2007 Arnaud et al,73 2007 Phillips et al,65 2006 Nishimoto et al,37 2006 Nout et al,57 2006 Meling et al,41 2006 Schulten et al,54 2006 Satoh et al,74 2006 Meazzini et al,56 2005 Kubler et al,21 2004 Arnaud et al,60 2004 Tunc¸bilek et al,53 2004 Hierl et al,45 2003 Wiltfang et al,71 2002 Kubler et al,43 2002 Holmes et al,13 2002 Toth et al,79 1998 Denny et al,47 1994 Posnick et al,59 1994 Feng et al,63 1994 Posnick et al,61 1993 Mulliken et al,64 1991 David et al,66 1990 Bu et al,62 1989 Kreiborg et al,67 1986 Kaban et al,68 1986
Reason for Exclusion 2 3 3 3, 4 1 3 2 3, 4 3 3 4 1, 3 4 3, 4 3 3 3 3 3, 4 1, 3 4 3 3 3 4, 3 3 4 1, 3 3, 4 3 1, 3 3, 4 1 3, 4 3 3 3 3 3 3 3, 4 3 3 3 3
Reasons for exclusion: (1) case series with inadequate sample size; (2) Le Fort I osteotomy included in sample; (3) incomplete or no follow-up data reported; (4) incomplete or no cephalometric analysis provided. Saltaji et al. Le Fort III Distraction Versus Le Fort III Osteotomy. J Oral Maxillofac Surg 2014.
from 2.2 to 24 years and included growing and nongrowing patients. The follow-up period ranged from 1 to 14.5 years. Finally, 53 patients with Crouzon, 44 with Apert, 26 with Pfeiffer, and 5 with other syndromes were included in these studies.
LFIII-DO Technique Nine studies reporting on the LFIII-DO procedure were finally selected: 3 clinical trials20,27,28 and 6 case series.29-34 Most of the studies were from the United States, with a few from Korea, Italy, and Brazil. The sample sizes of the studies ranged from 10 to 41 patients, aged 3 to 32.3 years. The breakdown of the diagnoses for the studies was as follows: 79 with Crouzon, 68 with Apert, 22 with Pfeiffer, 2 with Marshall-Stickler, and 9 with other syndromes. These patients underwent a latency period generally of 5 days (range 2 to 7), with a rate of distraction of 1 mm/day. Except for the study by Hopper et al,31 in which patients younger than 6 years underwent a distraction rate of 1.5/day. The consolidation period ranged from 4 to 12 weeks. In addition, the follow-up period was 1 to 5 years, except for 1 study,28 in which patients were followed up for up to 10 years. MIDFACIAL ADVANCEMENT AND RELAPSE
Conventional LFIII Osteotomy All the included LFIII osteotomy studies demonstrated a mean midfacial advancement of 8 to 12 mm, as indicated by the change in the A-point and/or orbitale. The horizontal short-term follow-up in 2 studies showed a maximum rate of relapse of 8.7% at the A-point and 11.9% at the orbitale.27,35 However, 1 study20 demonstrated a far more severe maximum rate of relapse of 50% at both the A-point and the forehead. The horizontal long-term measurements exhibited growth, rather than relapse, in most studies. The maximum growth was demonstrated at the site of the orbitale, with a 13% increase.35 However, Bachmayer et al36 reported a mild long-term relapse rate of 9.7%. Regarding the vertical dimension, the movement was less than 10 mm in 3 studies27,35,36 and 11.7 mm in the study by Ousterhout et al.3 The short-term relapse data showed a maximum of 1.36 mm from all the available studies. Of the 3 studies providing long-term relapse measurements, 2 studies3,36 presented a maximum relapse rate of less than 5.5%, and 1 study35 demonstrated greater vertical relapse. Tables 4 and 5 provide additional details of the amount of advancement and the short- and long-term stability using the LFIII procedure.
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Table 3. METHODOLOGIC SCORE
Methodologic Quality Item
OF SELECTED STUDIES
Bradley et al20
Meazzini et al28
Shetye et al27
Shetye et al35
Bachmayer et al36
Ousterhout et al3
UU
UU
UU
UU
UU
UU
U
U
U
U
U
U U
U s
s
Iannetti et al29 U
Lee et al30
Hopper et al31
Lima et al34
Shetye et al33
Fearon32
UU
UU
UU
UU
Us
U
U
U
U
U U
s
s
U
U
U
U
U
s
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U s
U U
U UU
U U
s U
s s
s sU
U s U
U U UU
U U U
U U UU
46.4
57.1
60.7
53.6
42.9
57.1
50.0
50.0
57.1
60.7
67.8
s s
42.9
Each check mark indicates the study satisfactorily fulfilled the methodologic criterion (1 check point); the not equal symbol indicates the criterion was partially fulfilled (0.5 check point); and the ‘‘x’’ indicates the methodologic criterion was not fulfilled (0 check point). Maximum number of check marks was 14. Abbreviations: CI, confidence interval; SD, standard deviation. * Two criteria included in entry; thus, 2 responses given. Saltaji et al. Le Fort III Distraction Versus Le Fort III Osteotomy. J Oral Maxillofac Surg 2014.
LE FORT III DISTRACTION VERSUS LE FORT III OSTEOTOMY
Eligibility criteria—clearly described; adequate* Sample size—calculated; adequate* Randomization or consecutive selection—stated Blinding of assessor—stated Intervention details—clearly described Outcome measures—clearly described Selective reporting—avoided Withdrawals—reported Adverse effects—described Data analysis—appropriate Point estimates and variability—exact P value; variability measures, SD, or CI* Quality score (% of total)
23,24
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SALTAJI ET AL
Table 4. DESCRIPTION OF FINALLY SELECTED STUDIES REPORTING ON CONVENTIONAL LFIII OSTEOTOMY
Investigator
Study Design Country
Bradley et al20
CT, R
USA
Shetye et al35
CS, R
USA
Shetye et al27
CT, R
USA
Bachmayer et al36 CS, R
Canada
Ousterhout et al3 CS, R
USA
Sample Size
Age at Surgery (yr)
G1: 12 G2: 11
G1: 9 (range 5-22) G2: 11 (range 7-14)
Diagnosis
G1: 42% Crouzon, 25% Apert, 17 Pfeiffer,17% other G2: 36% Crouzon, 9% Apert, 27% Pfeiffer, 27% other 25 (11 M, 14 F) 5.8 (range 3.8–10.9) 10 Crouzon, 9 Apert, 6 Pfeiffer G1: 20 (10 M, 10 F) G1: 7.1 G1: 45% Crouzon, G2: 20 (11 M, 9 F) G2: 5.7 35% Apert, 20 Pfeiffer G2: 40% Crouzon, 35% Apert, 25% Pfeiffer 19 (12 M, 7 F) 7.1 (range 2.2-10) 10 Apert, 7 Crouzon, 2 Pfeiffer 21 17 (range 12-24) 7 Apert, 10 Crouzon, 4 Pfeiffer
Follow-Up (yr) 1-2
1 and 10 1
5.3 (range 2-14.5) 1-9
Abbreviations: CS, case series; CT, clinical trial; F, female; M, male; R, retrospective study. Saltaji et al. Le Fort III Distraction Versus Le Fort III Osteotomy. J Oral Maxillofac Surg 2014.
LFIII-DO Technique The final included reports of the LFIII-DO technique demonstrated a mean horizontal midfacial advancement of 9 to 16 mm, as indicated by the change in the A-point and/or orbitale. The horizontal short-term relapse rate was 14.4% in 1 study,31 although the remaining studies demonstrated a relapse rate of less than 10%. Moreover, 3 studies27,29,33 even showed additional advancement without any relapse. The long-term follow-up results were more limited, with most showing a relapse rate of less than 10%, except for 1 study,28 which reported a relapse rate of 18.5%, as indicated by the change in the A-point. The magnitude of vertical advancement was recorded in only 4 studies,27,31,33,34 with none reporting any long-term results. Tables 6 and 7 provide additional details on the amount of advancement and the short- and long-term stability after LFIII-DO in the final selected studies. POOLING OF DATA
Pooling the data from these 12 reports was deemed not suitable because of clinical and methodologic heterogeneity across the studies.24
Discussion Patients with Crouzon, Apert, and Pfeiffer syndromes exhibit midfacial hypoplasia owing to craniostenosis, which is usually corrected with midfacial
surgical advancement.4,28 The present systematic review examined the short- and/or long-term skeletal stability of conventional LFIII and/or LFIII-DO as evaluated using lateral cephalograms. Of the studies found, 12 reports were finally selected, 5 of which had focused on LFIII and 7 on LFIII-DO. MIDFACIAL ADVANCEMENT
Conventional LFIII osteotomy can achieve a mean midfacial advancement of 8 to 12 mm. However, for severe advancements of more than 20 mm, this cannot be safely achieved using conventional LFIII osteotomy.79-81 With the introduction of LFIII-DO, the amount of midfacial advancement achieved has increased,28 which has also been supported by the results from the present systematic review. The findings of our systematic review have shown that the LFIII advancement ranged from 2 to 17 mm, and the LFIIIDO advancement ranged from 5 to 22 mm. The greater range of advancement with the LFIII-DO procedure conceivably allows the opportunity for patients requiring a larger amount of midfacial advancement to receive it. SHORT-TERM STABILITY
With respect to LFIII-DO, the study by Arnaud et al73 proposed that a short consolidation period might contribute to incomplete ossification and persistent elasticity of the soft tissue30 and hence an increased
966
Table 5. DESCRIPTIVE STATISTICS OF ADVANCEMENT AND SHORT- AND LONG-TERM RELAPSE OF STUDIES REPORTING ON CONVENTIONAL LFIII OSTEOTOMY
Horizontal Dimension* Investigator Shetye et al27
Shetye et al35 Bradley et al20
Ousterhout et al3
DT2T1y
DT3T2
DT4T2
DT2T1y
DT3T2
DT4T2
G1: A, 9.78 3.81; Or, 10.48 3.76 G2: A, 10.67 3.34; Or, 11.12 3.4 A, 10.72 3.53 Or, 11.39 3.62 G1: A, 11; SNA , 2; forehead, 11 G2: A, 10; SNA , 1; forehead, 12
G1: A, 0.54 mm (+5.6%); Or, 1.25 mm (11.9%) G2: A, 0.93 mm (8.7%); Or, 0.63 mm (5.7%) A, 0.10 mm (+0.9%) Or, 0.11 mm (0.9%) G1: A, 5 mm (45.5%); SNA , 2 (100%); forehead, 4 mm (36.4%) G2: A, 5 mm (50%); SNA , 1 (100%); forehead, 6 mm (50%) NR
NR
G1: A, 0.95 5.55; Or, 0.5 4.62 G2: A, 4.83 5.0; Or, 3.5 3.63 A, 3.77 5.55 Or, 2.70 4.92 NR
G1: A, 1.36 mm; Or, 0.78 mm G2: A, 0.63 mm; Or, 0.25 mm A, 0.47 mm Or, 0.43 mm NR
NR
Advancement: 12.4 4.8 mm Advancement: 8.6 mm (range 2–17)
NR
A, 0.04 mm (+0.3%) Or, 1.48 mm (+13%) NR
1.2 mm (9.7%) 1.0 mm (+11%)
Repositioning of maxilla, 2.5 mm Repositioning of maxilla, 11.7 mm
NR NR
A, 6.4 mm Or, 0.84 mm NR
0.3 mm (5.5%) 0.33 mm (2.8%)
Abbreviations: A, A-point, deepest point on contour of alveolar projection; ANS, anterior nasal spine point; NR, not reported; Or, orbitale point; SNA , angle between anterior cranial base and A-point; T1, before LFIII surgery; T2, after LFIII surgery; T3, short-term data (follow-up
Le Fort III Distraction Osteogenesis Versus Conventional Le Fort III Osteotomy in Correction of Syndromic Midfacial Hypoplasia: A Systematic Review Humam Saltaji, DDS, MSc,* Mostafa Altalibi, BSc, DMD, GPR,y Michael P. Major, DMD, MSc, FRCD(C),z Muhammed H. Al-Nuaimi, BSc,x Sawsan Tabbaa, DDS, MSc,k Paul W. Major, DDS, MSc, FRCD(C),{ and Carlos Flores-Mir, DDS, DSc, FRCD(C)# Purpose:
It has been debated whether the Le Fort III procedure using distraction osteogenesis (LFIIIDO) reduces the risk of postintervention relapse compared with conventional Le Fort III (LFIII) osteotomy in the correction of syndromic midfacial hypoplasia. Our objective was to evaluate the short- and long-term stability of the bony structures after midfacial advancement using conventional LFIII osteotomy versus LFIII-DO in patients with syndromic midfacial hypoplasia.
Materials and Methods:
We performed a systematic review of the published data. An electronic search of 10 databases was performed from their inception through June 2012. The reference lists of the relevant publications were also reviewed. Studies were considered for inclusion if they were longitudinal clinical studies with follow-up periods of at least 1 year after surgery (LFIII group) or at the end of the consolidation period (LFIII-DO group). Study selection, risk of bias assessment, and data extraction were performed in duplicate. The methodologic and clinical heterogeneity across the studies precluded combining the findings using meta-analyses.
Results:
A total of 57 reports met the initial search criteria, and 12 reports were finally selected. The studies demonstrated a mean midfacial advancement of 8 to 12 mm in the LFIII group and 9 to 16 mm in the LFIII-DO group. For the LFIII group, horizontal short-term follow-up showed a maximal rate of relapse of 8.7 to 11.9% in 2 studies, with 1 study demonstrating a far more severe rate of maximal relapse of 50%. For the LFIII-DO procedure, the horizontal short-term relapse rate was 14.4% in 1 study, with the remainder demonstrating a rate of relapse of less than 10%. Moreover, 3 studies even showed additional advancement without any rate of relapse.
Conclusions: Current evidence suggests that conventional LFIII and LFIII-DO techniques can effectively advance the midface forward in patients with syndromic midfacial hypoplasia and have good to excellent stability, with a mild rate of relapse. However, the LFIII-DO technique appears to achieve a greater amount *PhD Candidate and Resident, Orthodontic Graduate Program,
#Associate Professor and Head, Division of Orthodontics,
University of Alberta Faculty of Medicine and Dentistry School of
University of Alberta Faculty of Medicine and Dentistry School of
Dentistry, Edmonton, AB, Canada.
Dentistry, Edmonton, AB, Canada.
yMSc Resident, University of Alberta Faculty of Medicine and
Conflict of Interest Disclosures: None of the authors reported any
Dentistry School of Dentistry, Edmonton, AB, Canada.
disclosures.
zClinical Assistant Professor, University of Alberta Faculty of
Address correspondence and reprint requests to Dr Saltaji: Ortho-
Medicine and Dentistry School of Dentistry, Edmonton, AB, Canada.
dontic Graduate Program, 5-476, Edmonton Clinic Health Academy,
xDental Student, University of Alberta Faculty of Medicine and Dentistry School of Dentistry, Edmonton, AB, Canada.
University of Alberta Faculty of Medicine and Dentistry School of Dentistry, 11405-87 Ave, Edmonton, AB T6G 1C9 Canada; e-mail:
kAssistant Professor, State University of New York at Buffalo
[email protected]
School of Dental Medicine, Buffalo, NY.
Received September 7 2013
{Professor and Chair, University of Alberta Faculty of Medicine
Accepted September 24 2013
and Dentistry School of Dentistry, and Senior Associate Dean,
Ó 2014 American Association of Oral and Maxillofacial Surgeons
University of Alberta Faculty of Medicine and Dentistry, Edmonton,
0278-2391/13/01232-9$36.00/0
AB, Canada.
http://dx.doi.org/10.1016/j.joms.2013.09.039
959
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LE FORT III DISTRACTION VERSUS LE FORT III OSTEOTOMY
of advancement with a lower rate of relapse compared with the conventional LFIII technique. Ó 2014 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 72:959-972, 2014 Craniofacial synostosis syndromes (e.g., Crouzon and Apert syndromes) are craniofacial anomalies characterized by the premature fusion of the craniofacial sutures; this results in midface hypoplasia.1 Syndromic midfacial hypoplasia requires orthognathic surgery, which aims to restore the functional and esthetic impairment and to establish proper occlusion and increase airway patency by advancing the midface.2-4 The traditional surgical procedure for correcting midfacial hypoplasia is a Le Fort III (LFIII) osteotomy.3 This technique was first introduced in 19505 and was then revised and modified over time by multiple investigators.6-9 In more recent years, however, a variation of the LFIII procedure came in to use, using distraction osteogenesis (LFIII-DO). This technique was first described in 199510 and has become an apparently effective and reliable technique in the management of syndromic midfacial hypoplasia.11-13 Both conventional LFIII and LFIII-DO surgeries are considered complex techniques, because they require a multidisciplinary team, including a plastic and craniofacial surgeon, ophthalmologist, otolaryngologist, clinical psychologist, speech pathologist, dietician, audiologist, and orthodontist.14,15 Both the surgeon and the orthodontist play key roles in the surgical planning and managing the pre- and postintervention occlusion, oral function, and esthetic appearance. However, the management of syndromic midfacial hypoplasia has been a challenge for the reconstructive team, because the surgical approach has been associated with multiple complications and adverse effects, ranging from mild relapse to blindness and death.16-19 The conventional LFIII osteotomy procedure was reported to be more invasive than the LFIII-DO technique, because the former has usually required the use of bone grafts and has been associated with greater soft tissue tension and higher complication rates than the LFIII-DO technique.20 It has been debated whether the LFIII-DO technique reduces the risk of postintervention relapse, owing to the gradual nature of the approach, which allows progressive bone regeneration and soft tissue adaptation.20,21 To meaningfully evaluate the effectiveness of the interventions, it is important to assess not only the immediate postintervention changes, but also the long-term changes and occurrence of relapse. Therefore, the objectives of the present report were to systematically review the short- and long-term skeletal stability after midfacial advancement between the conventional LFIII osteotomy and the LFIII-DO procedures in patients with midfacial hypoplasia due to craniofacial synostosis syndromes.
Materials and Methods The reporting of the present systematic review was performed in accordance with the PRISMA statement for reporting systematic reviews of health sciences.22
DATA SOURCES AND SEARCHES
Comprehensive searches up to July 10, 2012 were conducted using the following electronic bibliographic databases: PubMed (1966 to July 2012, week 2); MEDLINE (1980 to 2012, week 28); EMBASE (1980 to 2012, week 28); ISI Web of Science (1965 to July 10, 2012); Evidence-Based Medicine (EBM) Reviews–Cochrane Central Register of Controlled Trials (1991 to July 2012); All EBM Reviews, including the Cochrane Database of Systematic Reviews, American College of Physicians (ACP) Journal Club, Database of Abstracts of Reviews of Effects (1991 to July 2012); and HealthSTAR (1966 to July 2012). An update of the search was conducted on March 21, 2013. The search strategy was devised with the help of a health science librarian specializing in the field of dental research. The key words used varied slightly to be tailored to the databases but generally involved ‘‘Le Fort III,’’ ‘‘distraction osteogenesis,’’ ‘‘midfacial advancement,’’ ‘‘craniofacial dysostosis,’’ ‘‘craniosynostosis,’’ ‘‘Apert,’’ ‘‘Crouzon,’’ and ‘‘Pfeiffer.’’ The initial search strategy was designed for PubMed (Table 1) and was then adapted to the other databases. Of the relevant studies finally selected, manual searches were subsequently performed of the references, and, in cases of ambiguity, the authors of the reports were contacted. No restrictions were applied regarding publication year or language. When additional information was needed, efforts were made to contact the authors. Table 1. SEARCH STRATEGY USED IN PUBMED
1. Le Fort III OR Le Fort III OR distraction* osteogenesis OR midface* advancement OR mid-fac* advancement OR midface* osteotomy OR mid-fac* osteotomy 2. Craniofacial dysostosis OR craniosynostosis OR syndrome* OR mid-fac* hypoplasia OR midfac* hypoplasia OR mid-fac* retrusion OR midfac* retrusion OR maxilla* hypoplasia OR cleft OR Apert OR Crouzon OR Pfeiffer 3. #1 and #2 Saltaji et al. Le Fort III Distraction Versus Le Fort III Osteotomy. J Oral Maxillofac Surg 2014.
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SALTAJI ET AL STUDY SELECTION
The appropriate reports to be included fulfilled the following pre-established eligibility criteria: Population: Patients with midfacial hypoplasia due to craniofacial synostosis syndromes (e.g., Apert, Crouzon, Pfeiffer, and Saethre-Chotzen). Only human studies were eligible. No restrictions were applied regarding age or gender. Intervention: Surgical therapy to correct midface hypoplasia with conventional LFIII osteotomy or LFIII-DO. Comparison: Before and after treatment or conventional LFIII versus LFIII-DO or another equivalent intervention. Outcome: Stability of the outcome assessed at least 1 year after treatment. The data were considered shortterm when the follow-up period was less than 3 years and long-term when the follow-up period was at least 3 years. Horizontal and vertical changes in the maxilla and midface were assessed at the end of treatment and at least 1 year after treatment using the following points of interest: A-point, the deepest point on the contour of the alveolar projection; ANS point, anterior nasal spine; SNA angle, angle between the anterior cranial base and A-point; and Or, orbitale. Study Design: Longitudinal clinical studies with follow-up periods of at least 1 year after surgery (LFIII group) or after the end of the consolidation period (LFIII-DO group). Both prospective and retrospective studies, with more than 6 patients per intervention group, were included: randomized controlled trails (RCTs), nonrandomized controlled clinical trials, clinical trials, and case series studies with 6 or more patients. Three reviewers (H.S., M.A., M.E.) independently reviewed the list of titles and abstracts for inclusion. Once potentially adequate abstracts had been selected, the full reports were retrieved in a second final selection process. If the abstract was judged to contain insufficient information for a decision of inclusion or exclusion, the full report was obtained and reviewed before a final decision was made. Any discrepancies in the inclusion of the studies among the reviewers were addressed through discussion until a consensus had been reached. RISK OF BIAS ASSESSMENT
The methodologic quality of the included studies was assessed by 2 reviewers (H.S. and M.A.), and discrepancies were resolved by discussion until a consensus was reached. The studies were assessed according to a checklist of the following methodologic criteria23,24: eligibility criteria, sample size, randomization, blinding
of the outcome assessor, selective reporting, description of intervention details, description of outcome measures, description of withdrawals, description of adverse effects, and adequacy of data analysis. DATA EXTRACTION
The data were extracted for each of the selected studies according to the following outcomes: study design, age at surgery, sample size, diagnosis, follow-up period, latency period, distraction rate, consolidation period, mean movement obtained, and short- and long-term relapses in the horizontal and vertical dimensions. Study demographics such as publication year and country in which the study had been conducted were also collected. Data extraction were performed by the same 2 investigators (H.S. and M.A.), and discrepancies were resolved by discussion until consensus was reached. DATA SYNTHESIS
Pooling of the data to provide an estimate of the effectiveness of the interventions was planned for the studies reporting the same outcome measures. Furthermore, if sufficient trials were identified, subgroup and sensitivity analyses would be conducted. Finally, publication bias was to be assessed using a funnel plot by evaluating the degree of funnel plot asymmetry.25 Case series were planned to be analyzed separately from clinical trials owing to the high risk of publication bias in case series. Statistical heterogeneity across the studies was to be tested and evaluated using the c2 test and the I2 statistic,26 where I2 values greater than 50% indicate considerable heterogeneity. Clinical heterogeneity was evaluated by examining the various characteristics of the finally selected reports, including dis-similarity between the different types of interventions, outcomes, and patients. In the case of insufficient clinically homogeneous trials for any intervention, a qualitative synthesis was planned.
Results STUDY SELECTION
The search returned 1,237 potential records for inclusion, including 775 duplicates. Screening excluded 405 records because of the title and abstract. The remaining 57 full-text reports were retrieved for a more detailed evaluation, of which 10 reports20,27-35 fulfilled the inclusion and exclusion criteria. Additionally, 2 reports3,36 were identified through the reference list search; thus, 12 reports were finally included. The update of the search found no additional eligible reports to be included. A flow diagram of the data search is given
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LE FORT III DISTRACTION VERSUS LE FORT III OSTEOTOMY
in Figure 1. Of the 57 full reports initially selected, 37 were excluded because of an incomplete or no follow-up report of the data,13-15,21,37-69 6 because of an inadequate sample size,52,53,56,70-72 13 because of an incomplete or no cephalometric analysis reported,21,41-45,48,50,73-76 and 2 because Le Fort I osteotomies were included.77,78 The excluded studies and the reasons for their exclusion are listed in Table 2.
RISK OF BIAS ASSESSMENT
Included
Eligibility
Screening
Identification
Of the 12 studies finally selected, 3 were clinical trials20,27,28 and 9 were case series.3,29-36 The methodologic assessment tool portrayed a variance of 42.9 to 67.8% of the total scores. These findings
Relevant records identified through database searching (n=1237)
are summarized in Table 3 and represent moderate methodologic assessment scores.
STUDY CHARACTERISTICS
Of the 12 studies finally selected, 10 had been published between 2005 and 2012, including all the LFIIIDO studies. Eight studies had been conducted in North America,3,20,27,28,31-33,35,36 2 in Italy,28,29 and 1 each in Korea30 and Brazil.34 Conventional LFIII Osteotomy Five studies reporting on the LFIII osteotomy procedure were finally selected: 2 clinical trials20,27 and 3 case series3,35,36; all conducted in North America. The sample sizes ranged from 11 to 25 patients per intervention group, patient age at surgery ranged
Records excluded, duplicates (n=775)
Records screened based on title/abstract (n=462) Records excluded based on title/abstract (n=405) Full text articles retrieved for more detailed evaluation (n=57) Articles excluded based on inclusion-exclusion criteria (n=47) Studies met inclusionexclusion criteria (n=10) Articles identified through other sources (n=2)
Studies included in qualitative analysis, systematic review (n=12)
Studies included in quantitative analysis, metaanalysis (n=0) FIGURE 1. Flow diagram of the published data search according to the PRISMA statement.22 Saltaji et al. Le Fort III Distraction Versus Le Fort III Osteotomy. J Oral Maxillofac Surg 2014.
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Table 2. REPORTS NOT SELECTED FROM INITIAL ABSTRACT SELECTION LIST AND REASONS FOR EXCLUSION
Study Liu et al,77 2012 Nout et al,58 2012 Ahmad et al,49 2012 Coeugniet et al,48 2012 Warren et al,72 2012 Oberoi et al,14 2012 Yun et al,78 2011 Meling et al,42 2011 Nakajima et al,39 2011 Ettinger et al,46 2011 Sant’Anna et al,75 2010 Mitsukawa et al,70 2010 Oyama et al,76 2009 Uyama et al,50 2009 Ponniah et al,55 2008 Witherow et al,15 2008 Nishimoto et al,38 2008 Witherow et al,51 2008 Jensen et al,44 2007 Vachiramon et al,52 2007 Arnaud et al,73 2007 Phillips et al,65 2006 Nishimoto et al,37 2006 Nout et al,57 2006 Meling et al,41 2006 Schulten et al,54 2006 Satoh et al,74 2006 Meazzini et al,56 2005 Kubler et al,21 2004 Arnaud et al,60 2004 Tunc¸bilek et al,53 2004 Hierl et al,45 2003 Wiltfang et al,71 2002 Kubler et al,43 2002 Holmes et al,13 2002 Toth et al,79 1998 Denny et al,47 1994 Posnick et al,59 1994 Feng et al,63 1994 Posnick et al,61 1993 Mulliken et al,64 1991 David et al,66 1990 Bu et al,62 1989 Kreiborg et al,67 1986 Kaban et al,68 1986
Reason for Exclusion 2 3 3 3, 4 1 3 2 3, 4 3 3 4 1, 3 4 3, 4 3 3 3 3 3, 4 1, 3 4 3 3 3 4, 3 3 4 1, 3 3, 4 3 1, 3 3, 4 1 3, 4 3 3 3 3 3 3 3, 4 3 3 3 3
Reasons for exclusion: (1) case series with inadequate sample size; (2) Le Fort I osteotomy included in sample; (3) incomplete or no follow-up data reported; (4) incomplete or no cephalometric analysis provided. Saltaji et al. Le Fort III Distraction Versus Le Fort III Osteotomy. J Oral Maxillofac Surg 2014.
from 2.2 to 24 years and included growing and nongrowing patients. The follow-up period ranged from 1 to 14.5 years. Finally, 53 patients with Crouzon, 44 with Apert, 26 with Pfeiffer, and 5 with other syndromes were included in these studies.
LFIII-DO Technique Nine studies reporting on the LFIII-DO procedure were finally selected: 3 clinical trials20,27,28 and 6 case series.29-34 Most of the studies were from the United States, with a few from Korea, Italy, and Brazil. The sample sizes of the studies ranged from 10 to 41 patients, aged 3 to 32.3 years. The breakdown of the diagnoses for the studies was as follows: 79 with Crouzon, 68 with Apert, 22 with Pfeiffer, 2 with Marshall-Stickler, and 9 with other syndromes. These patients underwent a latency period generally of 5 days (range 2 to 7), with a rate of distraction of 1 mm/day. Except for the study by Hopper et al,31 in which patients younger than 6 years underwent a distraction rate of 1.5/day. The consolidation period ranged from 4 to 12 weeks. In addition, the follow-up period was 1 to 5 years, except for 1 study,28 in which patients were followed up for up to 10 years. MIDFACIAL ADVANCEMENT AND RELAPSE
Conventional LFIII Osteotomy All the included LFIII osteotomy studies demonstrated a mean midfacial advancement of 8 to 12 mm, as indicated by the change in the A-point and/or orbitale. The horizontal short-term follow-up in 2 studies showed a maximum rate of relapse of 8.7% at the A-point and 11.9% at the orbitale.27,35 However, 1 study20 demonstrated a far more severe maximum rate of relapse of 50% at both the A-point and the forehead. The horizontal long-term measurements exhibited growth, rather than relapse, in most studies. The maximum growth was demonstrated at the site of the orbitale, with a 13% increase.35 However, Bachmayer et al36 reported a mild long-term relapse rate of 9.7%. Regarding the vertical dimension, the movement was less than 10 mm in 3 studies27,35,36 and 11.7 mm in the study by Ousterhout et al.3 The short-term relapse data showed a maximum of 1.36 mm from all the available studies. Of the 3 studies providing long-term relapse measurements, 2 studies3,36 presented a maximum relapse rate of less than 5.5%, and 1 study35 demonstrated greater vertical relapse. Tables 4 and 5 provide additional details of the amount of advancement and the short- and long-term stability using the LFIII procedure.
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Table 3. METHODOLOGIC SCORE
Methodologic Quality Item
OF SELECTED STUDIES
Bradley et al20
Meazzini et al28
Shetye et al27
Shetye et al35
Bachmayer et al36
Ousterhout et al3
UU
UU
UU
UU
UU
UU
U
U
U
U
U
U U
U s
s
Iannetti et al29 U
Lee et al30
Hopper et al31
Lima et al34
Shetye et al33
Fearon32
UU
UU
UU
UU
Us
U
U
U
U
U U
s
s
U
U
U
U
U
s
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U s
U U
U UU
U U
s U
s s
s sU
U s U
U U UU
U U U
U U UU
46.4
57.1
60.7
53.6
42.9
57.1
50.0
50.0
57.1
60.7
67.8
s s
42.9
Each check mark indicates the study satisfactorily fulfilled the methodologic criterion (1 check point); the not equal symbol indicates the criterion was partially fulfilled (0.5 check point); and the ‘‘x’’ indicates the methodologic criterion was not fulfilled (0 check point). Maximum number of check marks was 14. Abbreviations: CI, confidence interval; SD, standard deviation. * Two criteria included in entry; thus, 2 responses given. Saltaji et al. Le Fort III Distraction Versus Le Fort III Osteotomy. J Oral Maxillofac Surg 2014.
LE FORT III DISTRACTION VERSUS LE FORT III OSTEOTOMY
Eligibility criteria—clearly described; adequate* Sample size—calculated; adequate* Randomization or consecutive selection—stated Blinding of assessor—stated Intervention details—clearly described Outcome measures—clearly described Selective reporting—avoided Withdrawals—reported Adverse effects—described Data analysis—appropriate Point estimates and variability—exact P value; variability measures, SD, or CI* Quality score (% of total)
23,24
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Table 4. DESCRIPTION OF FINALLY SELECTED STUDIES REPORTING ON CONVENTIONAL LFIII OSTEOTOMY
Investigator
Study Design Country
Bradley et al20
CT, R
USA
Shetye et al35
CS, R
USA
Shetye et al27
CT, R
USA
Bachmayer et al36 CS, R
Canada
Ousterhout et al3 CS, R
USA
Sample Size
Age at Surgery (yr)
G1: 12 G2: 11
G1: 9 (range 5-22) G2: 11 (range 7-14)
Diagnosis
G1: 42% Crouzon, 25% Apert, 17 Pfeiffer,17% other G2: 36% Crouzon, 9% Apert, 27% Pfeiffer, 27% other 25 (11 M, 14 F) 5.8 (range 3.8–10.9) 10 Crouzon, 9 Apert, 6 Pfeiffer G1: 20 (10 M, 10 F) G1: 7.1 G1: 45% Crouzon, G2: 20 (11 M, 9 F) G2: 5.7 35% Apert, 20 Pfeiffer G2: 40% Crouzon, 35% Apert, 25% Pfeiffer 19 (12 M, 7 F) 7.1 (range 2.2-10) 10 Apert, 7 Crouzon, 2 Pfeiffer 21 17 (range 12-24) 7 Apert, 10 Crouzon, 4 Pfeiffer
Follow-Up (yr) 1-2
1 and 10 1
5.3 (range 2-14.5) 1-9
Abbreviations: CS, case series; CT, clinical trial; F, female; M, male; R, retrospective study. Saltaji et al. Le Fort III Distraction Versus Le Fort III Osteotomy. J Oral Maxillofac Surg 2014.
LFIII-DO Technique The final included reports of the LFIII-DO technique demonstrated a mean horizontal midfacial advancement of 9 to 16 mm, as indicated by the change in the A-point and/or orbitale. The horizontal short-term relapse rate was 14.4% in 1 study,31 although the remaining studies demonstrated a relapse rate of less than 10%. Moreover, 3 studies27,29,33 even showed additional advancement without any relapse. The long-term follow-up results were more limited, with most showing a relapse rate of less than 10%, except for 1 study,28 which reported a relapse rate of 18.5%, as indicated by the change in the A-point. The magnitude of vertical advancement was recorded in only 4 studies,27,31,33,34 with none reporting any long-term results. Tables 6 and 7 provide additional details on the amount of advancement and the short- and long-term stability after LFIII-DO in the final selected studies. POOLING OF DATA
Pooling the data from these 12 reports was deemed not suitable because of clinical and methodologic heterogeneity across the studies.24
Discussion Patients with Crouzon, Apert, and Pfeiffer syndromes exhibit midfacial hypoplasia owing to craniostenosis, which is usually corrected with midfacial
surgical advancement.4,28 The present systematic review examined the short- and/or long-term skeletal stability of conventional LFIII and/or LFIII-DO as evaluated using lateral cephalograms. Of the studies found, 12 reports were finally selected, 5 of which had focused on LFIII and 7 on LFIII-DO. MIDFACIAL ADVANCEMENT
Conventional LFIII osteotomy can achieve a mean midfacial advancement of 8 to 12 mm. However, for severe advancements of more than 20 mm, this cannot be safely achieved using conventional LFIII osteotomy.79-81 With the introduction of LFIII-DO, the amount of midfacial advancement achieved has increased,28 which has also been supported by the results from the present systematic review. The findings of our systematic review have shown that the LFIII advancement ranged from 2 to 17 mm, and the LFIIIDO advancement ranged from 5 to 22 mm. The greater range of advancement with the LFIII-DO procedure conceivably allows the opportunity for patients requiring a larger amount of midfacial advancement to receive it. SHORT-TERM STABILITY
With respect to LFIII-DO, the study by Arnaud et al73 proposed that a short consolidation period might contribute to incomplete ossification and persistent elasticity of the soft tissue30 and hence an increased
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Table 5. DESCRIPTIVE STATISTICS OF ADVANCEMENT AND SHORT- AND LONG-TERM RELAPSE OF STUDIES REPORTING ON CONVENTIONAL LFIII OSTEOTOMY
Horizontal Dimension* Investigator Shetye et al27
Shetye et al35 Bradley et al20
Ousterhout et al3
DT2T1y
DT3T2
DT4T2
DT2T1y
DT3T2
DT4T2
G1: A, 9.78 3.81; Or, 10.48 3.76 G2: A, 10.67 3.34; Or, 11.12 3.4 A, 10.72 3.53 Or, 11.39 3.62 G1: A, 11; SNA , 2; forehead, 11 G2: A, 10; SNA , 1; forehead, 12
G1: A, 0.54 mm (+5.6%); Or, 1.25 mm (11.9%) G2: A, 0.93 mm (8.7%); Or, 0.63 mm (5.7%) A, 0.10 mm (+0.9%) Or, 0.11 mm (0.9%) G1: A, 5 mm (45.5%); SNA , 2 (100%); forehead, 4 mm (36.4%) G2: A, 5 mm (50%); SNA , 1 (100%); forehead, 6 mm (50%) NR
NR
G1: A, 0.95 5.55; Or, 0.5 4.62 G2: A, 4.83 5.0; Or, 3.5 3.63 A, 3.77 5.55 Or, 2.70 4.92 NR
G1: A, 1.36 mm; Or, 0.78 mm G2: A, 0.63 mm; Or, 0.25 mm A, 0.47 mm Or, 0.43 mm NR
NR
Advancement: 12.4 4.8 mm Advancement: 8.6 mm (range 2–17)
NR
A, 0.04 mm (+0.3%) Or, 1.48 mm (+13%) NR
1.2 mm (9.7%) 1.0 mm (+11%)
Repositioning of maxilla, 2.5 mm Repositioning of maxilla, 11.7 mm
NR NR
A, 6.4 mm Or, 0.84 mm NR
0.3 mm (5.5%) 0.33 mm (2.8%)
Abbreviations: A, A-point, deepest point on contour of alveolar projection; ANS, anterior nasal spine point; NR, not reported; Or, orbitale point; SNA , angle between anterior cranial base and A-point; T1, before LFIII surgery; T2, after LFIII surgery; T3, short-term data (follow-up
