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 Table of Contents  
REVIEW ARTICLE
Year : 2021  |  Volume : 8  |  Issue : 1  |  Page : 49-55

Comparison of conventional Le-fort I advancement, anterior maxillary segmental distraction, and distraction osteogenesis of maxilla for surgical management of cleft maxillary hypoplasia: A systematic review


1 Department of Maxillofacial Surgery, Saifee Hospital, Mumbai, Maharashtra, India
2 Department of Plastic and Reconstructive Surgery, Saifee Hospital, Mumbai, Maharashtra, India

Date of Submission16-Sep-2020
Date of Acceptance20-Nov-2020
Date of Web Publication13-Jan-2021

Correspondence Address:
Dr. Taher Abbas Mistry
Saifee Hospital, Mumbai, Maharashtra
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/jclpca.jclpca_28_20

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  Abstract 


This systematic review compares conventional Le-fort I advancement (CLO), anterior maxillary segmental distraction (AMD) and distraction osteogenesis of maxilla (DOM) for the treatment of cleft maxillary hypoplasia in terms of the amount of maxillary advancement achievable, relapse, residual velopharyngeal incompetence and soft tissue changes. All patients with maxillary hypoplasia secondary to cleft palate repair were taken into consideration irrespective of their gender, age and ethnic background. Literature research was done in databases PubMed, Ovid and Google scholar beta. From the original 429 articles identified, 17 articles were finally included, which passed the critical appraisal checklist and met the inclusion criteria. The mean advancement ranged from 6.59 mm to 16.5 mm for DOM, 6–14.28 mm for AMD and 5.17–7.2 mm for CLO. Relapse was 8.24%–45% for DOM, 4.6%–7% for AMD and 21.63%–63% for CLO. Velopharyngeal insufficiency increased significantly following Le-fort I advancement, while there was no significant change after anterior maxillary distraction and DOM. The ratio of soft tissue to hard tissue changes was greatest with AMD, followed by DOM and then CLO. Distraction osteogenesis of the maxilla and AMD are plausible treatment options for cleft maxillary advancement. Due to less stability and restricted amount of possible advancement, Le-fort I osteotomy should be reserved for minor skeletal discrepancies in cleft patients.

Keywords: Anterior maxillary distraction, cleft orthognatic surgery, distraction osteogenesis, Le-fort I advancement


How to cite this article:
Mistry TA, Mistry A. Comparison of conventional Le-fort I advancement, anterior maxillary segmental distraction, and distraction osteogenesis of maxilla for surgical management of cleft maxillary hypoplasia: A systematic review. J Cleft Lip Palate Craniofac Anomal 2021;8:49-55

How to cite this URL:
Mistry TA, Mistry A. Comparison of conventional Le-fort I advancement, anterior maxillary segmental distraction, and distraction osteogenesis of maxilla for surgical management of cleft maxillary hypoplasia: A systematic review. J Cleft Lip Palate Craniofac Anomal [serial online] 2021 [cited 2021 Apr 11];8:49-55. Available from: https://www.jclpca.org/text.asp?2021/8/1/49/306771




  Introduction Top


Cleft palate surgery results in inhibition of forward translation of the maxilla during growth, shortening of the basal length, and retrusion of the alveolar process. It is estimated that >45% of treated cleft palate patients have moderate-to-severe maxillary hypoplasia?.[1]

Conventional Le-fort I advancement for treating cleft maxillary hypoplasia has been reported by numerous authors with varying degrees of success. The relapse rate of conventional Le-fort I advancement in cleft patients is estimated to be around 25%–50% compared to 10% in noncleft individuals.[2],[3] The other reported complications include worsening of velopharyngeal insufficiency and inability to achieve the desired advancement due to tissue scarring resulting in compromised functional and esthetic results.

Distraction osteogenesis for maxillary advancement was introduced in 1993 and has been widely used for maxillary hypoplasia?.[4] Polley and Figueroa?[5] reported the use of rigid external device for maxillary advancement. The merits of distraction osteogenesis for the advancement of the maxilla is highlighted in cleft orthognathic due to its potential to minimize the limitations of conventional conventional Le-fort I advancement viz the rate of relapse and the amount of possible advancement. However, it has its own share of drawbacks, which include hardware failure, difficult patient compliance due to prolonged treatment time and the need for additional surgery for removal of the appliance.[6]

Anterior maxillary segmental distraction (AMD) for treating maxillary hypoplasia in cleft patients was introduced by Karakasis. Compared to the traditional methods of distraction, it has been reported to have less negative effects on velopharyngeal insufficiency.[7]

In this systematic review, the authors have compared the three different surgical procedures for managing cleft maxillary hypoplasia. The amount of distraction, stability, effects on velopharyngeal insufficiency, and soft-tissue changes have been evaluated for each procedure.

This systematic review will help clinicians to device an evidence-based treatment plan for various clinical scenarios of cleft maxillary hypoplasia.


  Materials and Methods Top


The protocol for the study was registered with PROSPERO (Registration ID: 197234). All the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, 2015 guidelines were followed in performing this systematic review.

Literature search

The guidelines of population, intervention, comparison, and outcome were observed for the literature search. A literature search was carried out using PubMed, Ovid, and Google scholar beta to identify articles reporting conventional Le-fort I advancement, maxillary distraction osteogenesis of the maxilla and AMD for the management of cleft maxillary hypoplasia. Medical subject headings terms used in the search were cleft and orthognathic with maxillary hypoplasia or maxillary advancement or cleft lip, cleft palate or orthognathic surgery or distraction osteogenesis or maxillary distraction.

Selection criteria

The following inclusion criteria were chosen initially to select potential articles from the published abstract results: (1) Human clinical trials; (2) No syndromic or medically compromised patients and no diseases; (3) No individual case reports (4) Articles reporting results of conventional Le-fort I advancement, maxillary distraction osteogenesis and AMD for management of cleft maxillary hypoplasia.

In cases of >1 publication on the same patient group for the same postoperative follow-up, the most informative and relevant article was included.

The selected articles were subjected to the Critical Appraisal Tools checklist[8] devised by Oxford University. Only those articles which passed the checklist were finally included in this study.

Data were extracted on the following items: year of publication, study design, follow-up, number and mean age of patients, mean amount of advancement achieved, stability of the results with a mean follow-up, latency, rate and rhythm, and consolidation period for distraction, effects on velopharyngeal insufficiency, soft-tissue changes and authors' inference.


  Results Top


The search strategy resulted in 429 articles on conventional Le-fort I advancement, maxillary distraction osteogenesis and AMD. After selection according to the inclusion criteria, 17 articles qualified for the final review analysis.

The final number of the articles selected according to the initial and final selection criteria are presented in [Table 1].[9],[10],[11],[12],[13],[14],[15],[16],[17],[18],[19],[20],[21],[22],[23],[24],[25]
Table 1: Articles included in the study

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Out of 17 studies, 12 were prospective[9],[10],[11],[16],[17],[18],[19],[20],[21],[23],[24] while the rest were retrospective.[12],[13],[14],[15],[25]

All the studies included patients with complete unilateral or bilateral cleft palate. The surgery was performed after alveolar bone grafting and the completion of skeletal maturation. While few studies included a hand-wrist radiograph to access the skeletal maturation,[11],[13] the remaining studies considered 18 years as the age limit for skeletal maturation and kept it as the lower age limit for inclusion.

The range of follow-up was from 6 months to 5 years. The immediate follow-up was within 1 month of surgery for conventional Le-fort I advancement and within 1 month after completion of distraction for AMD and distraction osteogenesis of the maxilla.

All the measurements for advancement were done using standardized lateral cephalograms except one[14] where standardized photographs were used for evaluation. Subnasale (soft tissue point at the base of the columella) was used as the reference point for measuring advancement for this study. For the rest of the studies Point A (deepest point on the anterior concavity of maxilla) was used to measure the advancement. The plane of advancement was either the palatal plane or the franfort's horizontal plane.

In the studies that evaluated maxillary distraction osteogenesis, 8 of them used rigid external device,[9],[10],[11],[13],[17],[18],[20],[21] while only 1 study used internal distractor[12] for distraction.

For AMD, 3 studies used rigid external device,[16],[24],[25] 2 studies[14],[23] reported the use of tooth-borne appliances. One study[24] had used bone borne distractor on the buccal surface of the maxilla.

Fixation following Le-fort I was done using miniplates in all the studies.

[Table 2],[Table 3],[Table 4] summarize the results of all the studies included in this systematic review. [Figure 1] demonstrates the amount of maxillary advancement plotted against the relapse rate for the three methods of maxillary advancement.
Table 2: Consolidation of results from distraction osteogenesis advancement

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Table 3: Consolidation of results from anterior maxillary segmental distraction

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Table 4: Consolidation of results from conventional Le-fort I advancement

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Figure 1: A chart plotted with amount of advancement on the X axis and percentage relapse on the Y axis for the three methods of maxillary advancement

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  Discussion Top


In the comprehensive care of cleft patients, managing cleft maxillary hypoplasia constitutes an arduous feat for cleft surgeons. Despite an array of researches being conducted on this subject at cleft centers around the globe, there still remains room for ambiguity on the clinical outcomes of various maxillary advancement procedures.

From the three techniques described in this review, it would be immature to conclude that one technique is better over another. Each has its own place in the management of maxillary hypoplasia; however, there are merits and demerits for all.

Age of intervention

Strong evidence suggests that surgical advancement of the maxilla should be deferred till skeletal maturity.[1] All the articles reviewed had their lower age limit set at 16 years for females and 18 years for males except two. One in which the lower age limit as low as 15 years.[20] Moreover, the other in which hand wrist radiograph was used to determining the skeletal maturity.[11]

The upper age limit could not be ascertained by this review as there was a marked variance among different studies. However, the mean age group of all studies was between 15.1 and 21.7 years.

All patients undergoing maxillary advancement had a successful alveolar bone grafting prior to maxillary advancement surgery. Chua et al.[13] have suggested 6 months postalveolar bone grating after which the patient can undergo advancement. However, clinical and radiological evaluation of the alveolar bone integration is warranted before surgery.

Amount of maxillary advancement

Chua et al.[13] in their meta-analysis have stated that the required amount of advancement in a cleft maxilla is often more as compared to a noncleft maxilla. Moreover, there is restriction in the advancement of cleft maxillary due to scarred palatal tissues.

In this review, the authors observed that the mean maxillary advancement achieved following conventional Le-fort I advancement was between 5.17 mm and 8.4 mm. For distraction osteogenesis, maxillary advancement ranged from 6.59 mm to 16.5 mm. For anterior segmental distraction, it ranged from 6 mm to 14.8 mm.

It is evident that the maximum amount of advancement can be achieved from distraction osteogenesis followed by AMD. The least is achieved with conventional Le-fort I advancement.

Some authors[19],[26] have suggested to include bilateral sagittal split osteotomy setback along with conventional Le-fort I advancement for deficiencies that are more than 6 mm. This could be plausible for borderline cases, however bilateral sagittal split osteotomy setback has its own limitations and larger setbacks may lead to a compromised profile.

Direction of maxillary movement

Cleft maxilla usually has hypoplasia in all three dimensions, namely, antero-posterior, vertical as well as transverse. When addressing the maxillary deficit, the vector of movement preferred is not in a true horizontal direction, but as advancement along with the clockwise rotation of the maxilla to increase the vertical height.

The transverse discrepancy can be addressed with surgically assisted palatal expansion; however, this procedure remains out of the scope of this review.

Downward movement of the maxilla by conventional Le-fort I osteotomy is considered as highly unstable.[3] The use of interpositional bone grafts from iliac crest and calvarium have decreased the likelihood of relapse; however, the results achieved as are far from ideal.

Baek et al.[11] have reported that a significantly greater downward movement is possible with distraction osteogenesis as compared to conventional Le-fort I.

Aksu et al.[10] in their study on distraction using rigid external device observed that there was a downward movement at the anterior nasal spine as well as the posterior nasal spine. Since the movement at the posterior nasal spine was more than at the anterior nasal spine, the net effect was a counter-clockwise rotation with anterior movement of the maxilla.

The vector of movement for AMD is limited by the arch form. Though some degree of the downward movement is possible at the anterior nasal spine without significantly disturbing the curve of Spee, the posterior nasal spine remains static.

Relapse

The amount of relapse for maxillary advancement in noncleft patients was reported to be near 10% following conventional orthognathic surgery[27] However, relapse is much more for maxillary advancement in cleft patients. This could be due to the resilience of the scarred tissues, which exert a pull on the advanced maxilla leading to a higher relapse.[5],[10],[12]

In this review, we have observed the relapse following conventional orthognathic surgery was from 21.63% to 63%. For distraction osteogenesis of the maxilla, it ranged from 22% to 45%. And for amsd, it was relatively low, ranging from 4.6% to 7%.

This review suggests AMD to be the most stable procedure amongst the three; however, literature on relapse following AMD was scarce, with only two studies reporting long term stability (2 years).[14],[16]

A correlation was noted between the amount of advancement and corresponding relapse for all three techniques. More the advancement attempted lead to a higher relapse.

Chua et al.[13] in their study have observed that relapse occurred mainly in the first 12 weeks following surgery for conventional Le-fort I advancement. A similar inference was deduced for AMD and distraction osteogenesis.[12]

Types of distractor

It would be astute to realize the profoundness of the effect the distractor has on the clinical outcomes of AMD and distraction osteogenesis of the maxilla.

For AMD, tooth-borne palatal distractors have been reported with a fairly acceptable rate of clinical success. Patient compliance is highly favorable. However, the stability and vector control during advancement is of concern. Moreover, it is supported on the molar teeth; hence, the health of teeth should be favorable for designing this type of distractor.

This review does not suggest any inferiority of tooth-borne palatal distractors over rigid external devices in terms of the amount of distraction. However, the vector of movement was more favorable for AMD with the rigid external device.

Rigid external device (red) is gaining incremental popularity in maxillary distraction due to its stability over internal distractors. It derives its support from the calvarium and hence it is more firm and robust. It has shown superiority to internal distractors in terms of vector control and stability for distraction osteogenesis of the maxilla, the outcome of which is that a greater amount of advancement is possible. The obvious disadvantage is of patient compliance, which has significantly restricted its use.

Burstein et al.[4] have used bone borne internal distractors for distraction osteogenesis with acceptable results. However, they have reported one case failure of distraction due to nonparalleling of vectors of the distractors during activation.

Chua et al.[13] have hypothesized that internal distractors provide better long-term stability than external distractors because internal distractors transpose, and distraction osteogenesis of the maxilla not pull maxilla, which may decrease relapse rates. However, such claims are yet to be proved with clinical evidence.

Velopharyngeal incompetence

Most of the patients suffering from cleft palate have mild to moderate velopharyngeal insufficiency. As per the report of Burstein et al.,[4] there is a general belief that velopharyngeal insufficiency worsens with advancements >10 mm for conventional Le-fort I advancement and 15 mm for distraction osteogenesis of the maxilla. They consider that slow movement in distraction osteogenesis of the maxilla tends to stretch the tissues and hence results in lesser worsening of velopharyngeal insufficiency. A study by Hongliang li further supports this inference, in which he has reported less deterioration in velopharyngeal function following distraction osteogenesis compared to conventional Le-fort I advancement.

Karabekmez?[27] in their study comparing AMD and Le-fort I, have reported a significant increase in velopharyngeal insufficiency following conventional Le-fort I advancement while no change following AMD.

Kumar et al.[18] used the Pitsburg's speech score to evaluate the speech and velopharyngeal function in Le-fort I advancement. Their inference was that the greater the amount of advancement, greater was the deterioration in the speech. A similar inference was given by Schwarz and Gruner[28] where they have stated that 84% of their patients had velopharyngeal insufficiency following conventional Le-fort I advancement.

A contrary report has been given by Seok et al.,[22] they have reported no statistically significant difference in speech outcome following conventional Le-fort I advancement. However, their sample size consisted of patients who had a good velopharyngeal function preoperatively.

In this review, we could not evaluate the long term results of whether the velopharyngeal insufficiency improves with time.

Soft-tissue changes

The final surgical outcome is assessed by the soft-tissue changes that result after the orthognathic procedure. Hence, it would be prudent to assess the superiority of the three procedures in terms of their soft-tissue response.

In a study comparing distraction osteogenesis of the maxilla and Le-fort I, Harada et al.[15] have concluded that soft-tissue changes were significantly greater following distraction osteogenesis of the maxilla not only due to greater advancement in the distraction osteogenesis of the maxilla group but also due to a higher soft tissue to hard tissue ratios for advancement. They believe that gradual stretching of tissues result in a better soft tissue response to maxillary advancement leading to a greater amount of advancement in the lip and greater change in the naso-labial angle. Markose et al.[14] have deduced the same inference when they compared AMD and conventional Le-fort I advancement.


  Conclusion Top


In managing cleft maxillary hypoplasia, it is extremely crucial to select the surgical procedure for advancement of the maxilla.

We can evidently conclude that conventional Le-fort I advancement should be reserved for mild cases, i.e., =8 mm.

AMD should be preferred in moderate cases of <10 mm. A requisite for AMD using palatal distractor is that it should be firmly supported by the posterior teeth, and the vector should be favorable for distraction.

Distraction osteogenesis is to be used for discrepancies requiring >10 mm advancement or in cases where clockwise movement is desired.

Relapse is considerably higher in these cases; hence, over correction of the defect should be considered.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

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Ross RB. Treatment variables affecting facial growth in complete unilateral cleft lip and palate. Cleft Palate J 1987;24:5-77.  Back to cited text no. 1
    
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Polley JW, Figueroa AA. Management of severe maxillary deficiency in childhood and adolescence through distraction osteogenesis with an external, adjustable, rigid distraction device. J Craniofac Surg 1997;8:181-5.  Back to cited text no. 5
    
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Figueroa AA, Polley JW. Management of severe cleft maxillary deficiency with distraction osteogenesis: Procedure and results. Am J Orthod Dentofacial Orthop 1999;115:1-12.  Back to cited text no. 6
    
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Karakasis D, Hadjipetrou L. Advancement of the anterior maxilla by distraction (case report). J Craniomaxillofac Surg 2004;32:150-4.  Back to cited text no. 7
    
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Rachmiel A, Even-Almos M, Aizenbud D. Treatment of maxillary cleft palate: Distraction osteogenesis vs. orthognathic surgery. Ann Maxillofac Surg 2012;2:127-30.  Back to cited text no. 9
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Baek SH, Lee JK, Lee JH, Kim MJ, Kim JR. Comparison of treatment outcome and stability between distraction osteogenesis and Le Fort I osteotomy in cleft patients with maxillary hypoplasia. J Craniofac Surg 2007;18:1209-15.  Back to cited text no. 11
    
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Burstein F, Soldanska M, Granger M, Berhane C, Schoemann M. Initial experience with a new intraoral midface distraction device. J Craniofac Surg 2015;26:1224-8.  Back to cited text no. 12
    
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