ORIGINAL ARTICLE
Maxillary Distraction Osteogenesis in Cleft Lip and Palate Cases With Midface Hypoplasia Using Rigid External Distractor: An Alternative Technique Gaurav Dua, BDS, Andrews Navin Kumar, BDS, Indranil Deb Roy, BDS, MDS, and Supriyo Kumar Roy, BDS, MDS Background: Patients with operated cleft lip and palate present with a problem of midface hypoplasia, and such patients have been traditionally treated with orthognathic surgery. Such a procedure has its own limitations of relapse and hence a newer modality of distraction osteogenesis with histiogenesis can be chosen to overcome such limitations for midfacial advancement. The purpose of this study is to evaluate an alternative technique and its postoperative stability in maxillary distraction osteogenesis in patients of cleft lip and cleft palate using a rigid external device (RED). Method: Nine patients with midface bone stock deficiency were selected for maxillary advancement. At the first surgery under general anesthesia, after Le Fort I osteotomy, RED system was used with the alternative technique. After distraction, evaluation was done for ease of the procedure, stability, and complications. Lateral cephalograms were evaluated at 3 stages: T1, pre-distraction; T2, post-distraction; and T3, 1 year post-distraction. Results: A mean 13.4-mm midface advancement was shown with bone formation at the pterygomaxillary region without losing the vector and having a standby mode in case the wire broke during distraction The results were stable even at 1 year of follow-up. Conclusion: Maxillary position improved in relation to the cranial base. This study showed that the RED was versatile in midface advancement. Key Words: Distraction osteogenesis (DO), cleft lip and cleft palate (CLCP), rigid external device (RED) (J Craniofac Surg 2014;25: 746–751)
D
istraction osteogenesis (DO) of long bones was first described by Ilizorov in Russia in the 1950s.1 The publication appeared in What Is This Box? A QR Code is a matrix barcode readable by QR scanners, mobile phones with cameras, and smartphones. The QR Code links to the online version of the article.
From the Army Dental Centre, Research and Referral Hospital, New Delhi, India. Received April 24, 2013. Accepted for publication January 7, 2014. Address correspondence and reprint requests to Gaurav Dua, BDS, Army Dental Centre (R&R), Delhi, New Delhi, India; E-mail: [email protected] The authors report no conflicts of interest. Copyright © 2014 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000000735
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Russian language in 1969. A search for literature for first publication on midface distraction for advancement with rigid external device (RED) for hypoplastic maxilla was demonstrated by Raschmeil et al in 1993.2 The DO of maxilla for advancement is considered to be superior to conventional orthognathic surgery in management of severe maxillary deficiency in cleft lip and cleft palate (CLCP) patients.3 DO provides a gradual distraction of maxilla bringing about changes in both vertical and horizontal vectors. The RED device requires a rigid intraoral appliance to apply traction through the dentition to the entire dentoalveolar segment of maxilla after a Le Fort I osteotomy. Distraction carried out is dependent on the kind of osteotomy carried out and whether the distraction is done through the center of rotation of maxilla or above or below this. The center of rotation for maxilla lies just above the premolar roots. Movement of maxilla brought about by keeping the vector parallel to the center of rotation will bring about its horizontal movement only. A bent 3-hole titanium miniplate is kept parallel to this center of rotation if in case only horizontal movement is desired. Cases requiring movement in both vertical and horizontal vectors of the plating system can be kept above or below it. The number of teeth in the maxillary arch also plays an important role in providing sufficient support. In absence of sufficient tooth support, unfavorable maxillary posterior teeth extrusions occur instead of the desired skeletal changes thereby leading to unsatisfactory aesthetic results. The use of DO is a new and predictable method for maxillary bone elongation with new bone formation at the distraction site. In severe maxillary hypoplasia, this offers a viable alternative in which only the hypoplastic maxilla is addressed, although there have been several conflicting reports regarding its efficacy as well as shortcomings and high rate of relapse, and hence there is a need for this technique to be used judiciously and with care.4 Shortcomings and tendency to relapse in such patients have been largely due to the (1) large advances made greater than 1 cm, (2) scarring in CLCP patients due to previous surgeries, and (3) timing of such distractions wherein once maxillary growth may be over, there is some growth potential that still remain in the mandible. Distractions are better in cases of CLCP due to gradual traction forces forming membranous bones along with soft tissue histiogenesis, a necessity in such patients. This soft tissue drape governs the extent of distraction and also the tendency to relapse.
PATIENTS AND METHODS Patients Nine patients with midface deficiency were referred from the Department of Orthodontics, Army Dental Centre, Research and Referral Hospital between January 2008 and July 2011, and were selected for this study (Tables 1 and 2). The mean age of patients was 18.8 years (range 17–22 years). The study group included 6 males and 3 females. Five patients had
The Journal of Craniofacial Surgery • Volume 25, Number 3, May 2014
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
The Journal of Craniofacial Surgery • Volume 25, Number 3, May 2014
Maxillary DO in Cleft Lip and Palate
TABLE 1. Master Chart
NG, nasogastric tube.
unilateral cleft lip and palate and 4 had bilateral cleft lip and palate. The maxillary advancement was planned based on clinical evaluation for aesthetics, occlusion, and cephalometric values (Fig. 1). Rigid external distractor (KLS Martin) (Fig. 2) was used in all cases. Before surgery, a cobalt-chromium intraoral splint with bilateral eyelets at canine region was fabricated and checked for fit and discrepancies. The appliance was cemented using a luting glass ionomer cement (Figs. 3–5). This appliance was used for 2-fold purpose, firstly to act as a holding device to provide anchorage during distraction and secondly as a salvage unit for intraoral dentoalveolar distraction if intranasal distraction fails.
Method Preoperatively, all patients underwent presurgical orthodontics in Department of Orthodontia. Once a stable occlusion was
achieved in the presurgical phase, the patient’s head was shaved and marking for cranial screw was made. This was done bilaterally 2 to 3 cm above the auricle with indelible markers and kept parallel to the Frankfurt horizontal (FH) plane. This marking reduces intraoperative time in placement of the distractor frame. A high-level step maxillary Le Fort I osteotomy was performed keeping it 5 mm away from the roots. The osteotomy was kept standard for all patients, starting at pyriform rim extending backwards and downwards running laterally and posteriorly to zygomatic buttress to end above the maxillary tuberosity (Fig. 6). Nasal septum and lateral nasal walls were osteotomized followed with pterygoid dysjunction with no attempt to downfracture the maxilla. A 2 3 hole titanium miniplate was adapted and fixed at the pyriform rim keeping the medial-most hole free and bent at 45 degrees and the rest fixed with 5-mm Ti screws. Bilaterally, a 26-G wire was bodied into NG tube and fixed to the distractor ports and traction carried out until taut intraoperatively (Figs. 7 and Fig. 8).
TABLE 2. Result Parameters Variables Mean
T1 (Preop)
Midface advancement
11 mm (planned) 46.1 mm 48.6 mm 72.6 deg 82 deg 9 deg 32.8 deg 67.5 deg −15 deg
A-X (sagittal) A-Y (vertical) SNA SNB ANB SN mandibular plane Nasolabial angle Facial convexity angle
T2 (Post-DO) 13.4 mm (achieved) 59.5 mm 51.2 mm 83.3 deg 82 deg 2.2 deg 33.1 deg 84.7 deg 11.2 deg
T3 (1 yr After DO) 11.1 mm (achieved) 57.22 mm 52.3 mm 82.2 deg 82.6 deg 2.4 deg 33.1 deg 84.7 deg 11.2 deg
© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
Mean Final Achieved 2.3 mm (relapse) 11.12 mm 3.7 mm 9.5 deg 0.6 deg 6.5 deg 0.3 deg 17.2 deg 26.2 deg
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The Journal of Craniofacial Surgery • Volume 25, Number 3, May 2014
Dua et al
FIGURE 3. Co-Cr splint fabricated on die stone.
FIGURE 1. Representation of landmarks and constructed lines used to identify craniofacial and dental parameters on lateral cephalometric radiograph. The following points were assessed: N, nasion; S, sella; ANS, anterior nasal spine; PNS, posterior nasal spine; Ptm, pterygomaxillary fissure; A, subspinale; B, supramentale; Mx1, incisal edge of maxillary central incisor; Pg, pogonion; Gn, gnathion; Go, gonion; Me, menton; Mn1, incisal edge of mandibular central incisor; x axis, horizontal reference line—line through nasion rotated 7 degrees upward from sella-nasion line; y axis, vertical reference line—line perpendicular to horizontal reference line through sella.
The distractor frame was fixed onto the outer plate of the cranium keeping it parallel to the FH plane 2 to 3 cm above the pinna and 2 to 3 cm equidistant from the cranium (Figs. 9–16). Post-osteotomy, a latency period of 5 to 7 days was followed. Distraction at the rate of 0.5 mm (12 hourly) for 7 to 12 days was achieved. A consolidation period of 8 to 10 weeks was allowed. Principle governing consolidation at the end of 8 to 10 weeks is based on radiographic bone healing and presence of cortical outline. Radiographs are therefore taken at intervals of (1) start of distraction, (2) immediate post-distraction, (3) immediate postconsolidation, (4) 6-months follow-up, and (5) 1-year follow-up. After consolidation, the 3-hole titanium plate was removed followed by fixation at pyriform rim and zygomatic buttress under GA. This was followed with retention with Delaire reverse-pull head gear/face mask for 3 months. Clinicoradiological follow-up for stability and soft tissue response for 1 year post-distraction was made. Evaluation of lateral cephalograms was carried out at 3 different stages: T1, pre-distraction; T2, immediate post-distraction (on completion of advancement 12–15 days at the rate of 1 mm/day); and T3, 1-year post-distraction follow-up (Figs. 17–19). The landmarks selected were sella (S), center of sella turcica; nasion (N); A point (A), the deepest point in the curved bony outline of maxilla; and B point (B), the most posterior point in the outer contour of the mandibular alveolar process. Reference planes selected were sella-nasion plane (SN), plane representing the anterior cranial base; x axis (horizontal axis), constructed line at 7 degrees relative
FIGURE 4. Co-Cr splint trial.
to the S-N line; y axis (vertical axis), vertical line through sella perpendicular to x axis; and mandibular plane, tangent to the lower border of the mandible. In a total of 27 cephalograms (3 per patient) used, 8 selected variables were measured as skeletal linear measurements, skeletal angular measurements, and soft tissue measurements. Skeletal linear measurements were as follows: A–X, the shortest distance between y axis and A point along x axis indicating the position of maxilla in sagittal plane; and A–Y, the shortest distance between x axis and A point along y axis indicating the position of maxilla in vertical plane. Skeletal angular measurements were as follows: SNA and SNB angles, which denoted the position of the maxilla and mandible in relation to the anterior cranial base, respectively (normal SNA = 82 ± 2 degrees and SNB = 80 ± 2 degrees); ANB denoting the relation of maxilla and mandible to each other (normal 2–4 degrees); and SN mandibular plane denoting the growth pattern of mandible (normal 32 ± 2 degrees). Soft tissue measurements were nasolabial angle (Cm–Sn–Ls) formed between the columella tangent and the upper lip tangent (normal 102 ± 2 degrees) and the angle of facial convexity (G′–Sn–Pg′) formed by the intersection of the soft tissues glabella– subnasale–pogonion (normal −12 ± 4 degrees) (Fig. 1).
RESULTS Changes observed immediately after distraction showed a mean advancement of maxilla by 13.4 mm. A mean of 2.3 mm horizontal relapse was observed 1 year after distraction. All post-distraction changes were stable at 1 year of follow-up and
FIGURE 2. Rigid external distractor (KLS Martin) complete assembly.
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FIGURE 5. Co-Cr splint final cementation with luting glass ionomer cement.
© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
The Journal of Craniofacial Surgery • Volume 25, Number 3, May 2014
FIGURE 6. Le Fort I osteotomy cut.
Maxillary DO in Cleft Lip and Palate
FIGURE 8. Braided 26 G wire passed through the medial hole and through the nostrils.
the relapse was not significant. Bone formation at the pterygomaxillary region was noted in the study. Post-consolidation cusp fossa occlusion was maintained in all cases. A significant reduction in the facial concavity by 26.1 degrees, anterior movement of upper lip, and improvement of the nasolabial angle by 17.2 degrees was observed.
DISCUSSION Cleft lip and palate is a common congenital defect among developing countries. This is associated with speech problems, dental defects, and psychosocial restrictions, and presents with maxillary hypoplasia. Studies estimate that 25% to 50% of all patients with cleft lip and palate need maxillary advancement.5,6 Cleft patients are difficult to treat with traditional surgical/orthodontic approach.7 Current surgical/orthodontic protocols rely on Le Fort I maxillary advancement. The palatal scarring resists acute advancement and causes relapse. Traditional maxillary surgeries in cleft patients have reported 25% relapse after a mean 7.8 mm advancement.8 Severe cases may also require mandibular set back surgery. The drawback of this bi-jaw approach compromises the final lower facial balance and harmony. The age in which these surgeries can be carried
FIGURE 7. Adaptation of 2 3 hole miniplate with 5-mm Ti screws leaving the medial-most hole.
FIGURE 9. Preoperative frontal view.
out is limited. Orthopedic appliances used to correct maxillary deformity during growing age only camouflage the skeletal discrepancy.9 DO overcomes most of the problems associated with conventional surgery, can be done at any age with fewer complications, and is a better choice for cleft patients as the gradual traction force causes the formation of membranous bone and eliminates the need for bone grafting and donor-site morbidity.9,10 It also allows the growth of soft tissue, which yields longterm aesthetic facial balance. Rigid external distractor system is effective for maxillary hypoplasia in these patients. In a review of literature, the most common modes for distraction included 26 G braided wire looped thru a hole made lateral to pyriform rim or wires looped through the intraoral splint eyelets. These techniques were invariably not parallel to the center of rotation of maxilla thereby causing an open bite postoperatively. Also, these have a disadvantage
FIGURE 10. Preoperative occlusal.
© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
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The Journal of Craniofacial Surgery • Volume 25, Number 3, May 2014
Dua et al
FIGURE 11. Preoperative lateral occlusal.
FIGURE 15. Postoperative lateral profile.
FIGURE 12. Occlusal cleft.
FIGURE 13. Splint cemented.
FIGURE 14. Postoperative frontal profile.
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of bone cut through and cessation of distraction and ultimately relying on intraoral splint for dentoalveolar segment distraction. In our study, the technique of using a 3-hole miniplate was used. The plates were fixed using 2 5 mm Ti screws lateral to pyriform margin bilaterally and keeping the medial-most hole free and bent at 45 degrees to receive the 26 G braided wire. The adaptation of the plates was made parallel to the center of rotation of maxilla avoiding a postoperative open bite, deep bite, and reduction in maxillary alveolar bone height with adequate bone stock regenerate in posterior segment parallel to and in line with the distracted maxilla (Figs. 17–19). All these were evaluated postoperatively and a 1-year review conducted using lateral cephalometrics with changes in respect to x axis to point A in millimeters, point ANS to point A vertical in millimeters, and y axis to point PNS. This 26 G braided wire is looped around the medial-most hole, protected with a no. 12 nasogastric feeding tube, and brought out from the nares to be mounted onto the distraction device. Mean 2.3 mm posterior movement at a point was observed 1 year after distraction which measured 16.6% in comparison to 25% to 30% of relapse as seen in other studies. In our cases, common problems encountered were the vector determination and inability to change the vector. The study showed no significant changes in the mandibular position indicating the improved profile and maxillomandibular relation due to increase in the bony maxillary length. Soft tissue changes were corresponding to the hard tissues. The RED changed the concave profile into an aesthetic balanced profile. Extensive research has been carried out on the subject of aesthetic balanced profile for midface hypoplasia. Work by Yaremchuk11 on making concave faces convex is well established. He used alloplastic implants through intraoral and periorbital incisions for augmentation of facial skeleton. Pterygomaxillary region is the area where the surgeon seeks to achieve stability by placement of bone graft.12 Studies show that
FIGURE 16. Postoperative occlusion.
© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
The Journal of Craniofacial Surgery • Volume 25, Number 3, May 2014
Maxillary DO in Cleft Lip and Palate
FIGURE 19. T3 lateral cephalogram.
FIGURE 17. T1 lateral cephalogram.
DO provides a new sound bone in the pterygomaxillary area, providing stability.13 The new tissues are of the same morphology as the basic hard and soft tissues, and are hence stable. There were minimal dental changes 1 year after distraction. This indicated that the soft tissue changes achieved after DO were stable in accordance with the other studies.14 One limitation of this study is that we did not evaluate the quality of regenerate. Use of better and less invasive diagnostic tools such as 3D ultrasound scan reconstruction should be able to provide specific results.15 Studies recommend overcorrection in periods of growth to compensate for further facial growth in the surrounding tissues, particularly the mandible.14 The inability to predict future growth of the associated anatomical structures is crucial for preoperative planning.
CONCLUSIONS Patients with bone stock deficiencies in maxillary hypoplasia secondary to facial clefts present challenges to the surgeon. Maxillary DO permits a near-normal correction of the midface deficiency in cleft patients. In this study, the results achieved were superior to the conventional osteotomies and orthopedics. The cephalometric data showed stability after RED. Further long-term studies are recommended, with a larger sample size, randomized controlled samples, and longer follow-up, to assess the quality of regenerate. In the future, midface DO may benefit
FIGURE 18. T2 lateral cephalogram.
from automated light and continuous distraction. This will liberate patients from protracted distraction sessions and minimize discomfort. The procedure no longer would depend on activation of RED.
REFERENCES 1. Ilizarov GA, Ledyasev VI, Shitin VP. Experimental studies of bone lengthening. Eksp Khir Anesteziol 1969;14:3 2. Rachmeil A, Jackson IT, Potparic Z, et al. Midface advancement in sheep by gradual distraction: a 1 year follow-up study. J Oral Maxillofac Surg 1995;53:525–9 3. 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;8:181–185 4. Chin M, Toth BA. Distraction osteogenesis in maxillofacial surgery using internal devices: review of five cases. J Oral Maxillofac Surg 1996;54:45–53 5. Molina F. Distraction osteogenesis for the cleft lip and palate patient. Clin Plast Surg 2004;31:291–302 6. Swennen G, Dujardin T, Goris A, et al. Maxillary distraction osteogenesis: a method with skeletal anchorage. J Craniofac Surg 2000;11:120–127 7. McCance AM, Moss JP, Fright WR, et al. Three-dimensional analysis techniques—part 1. Three-dimensional soft-tissue analysis of 24 adult cleft palate patients following Le Fort I maxillary advancement: a preliminary report. Cleft Palate Craniofac J 1997;34:36–45 8. Hochban W, Ganss C, Austermann KH. Long-term results after maxillary advancement in patients with clefts. Cleft Palate Craniofac J 1993;30:237–243 9. Cope JB, Samchukov ML. Mandibular distraction osteogenesis: a historic perspective and future directions. Am J Orthod Dentofacial Orthop 1999;115:448–460 10. Figueroa AA, Polley JW. Management of severe cleft maxillary deficiency with distraction osteogenesis: procedure and results. Plast Reconstr Surg 1998;102:1360–1372 11. Yaremchuk MJ. Making concave faces convex. Aesth Plast Surg 2005;29:141–147 12. Sandor GK, Ylikontiola LP, Serlo W, et al. Midfacial distraction osteogenesis. Atlas Oral Maxillofac Surg Clin North Am 2008;16:249–272 13. Kusnoto B, Figueroa AA, Polley JW. Radiographic evaluation of bone formation in the pterygoid region after maxillary distraction with a rigid external distraction (RED) device. J Oral Maxillofac Surg 2000;58:959–969 14. Wiltfang J, Hirschfelder U, Neukam FW, et al. Long-term results of distraction osteogenesis of the maxilla and midface. Br J Oral Maxillofac Surg 2002;40:473–479 15. Hughes CW, Williams RW, Bradley M, et al. Ultrasound monitoring of distraction osteogenesis. Br J Oral Maxillofac Surg 2003;41:256–258
© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
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Maxillary Distraction Osteogenesis in Cleft Lip and Palate Cases With Midface Hypoplasia Using Rigid External Distractor: An Alternative Technique Gaurav Dua, BDS, Andrews Navin Kumar, BDS, Indranil Deb Roy, BDS, MDS, and Supriyo Kumar Roy, BDS, MDS Background: Patients with operated cleft lip and palate present with a problem of midface hypoplasia, and such patients have been traditionally treated with orthognathic surgery. Such a procedure has its own limitations of relapse and hence a newer modality of distraction osteogenesis with histiogenesis can be chosen to overcome such limitations for midfacial advancement. The purpose of this study is to evaluate an alternative technique and its postoperative stability in maxillary distraction osteogenesis in patients of cleft lip and cleft palate using a rigid external device (RED). Method: Nine patients with midface bone stock deficiency were selected for maxillary advancement. At the first surgery under general anesthesia, after Le Fort I osteotomy, RED system was used with the alternative technique. After distraction, evaluation was done for ease of the procedure, stability, and complications. Lateral cephalograms were evaluated at 3 stages: T1, pre-distraction; T2, post-distraction; and T3, 1 year post-distraction. Results: A mean 13.4-mm midface advancement was shown with bone formation at the pterygomaxillary region without losing the vector and having a standby mode in case the wire broke during distraction The results were stable even at 1 year of follow-up. Conclusion: Maxillary position improved in relation to the cranial base. This study showed that the RED was versatile in midface advancement. Key Words: Distraction osteogenesis (DO), cleft lip and cleft palate (CLCP), rigid external device (RED) (J Craniofac Surg 2014;25: 746–751)
D
istraction osteogenesis (DO) of long bones was first described by Ilizorov in Russia in the 1950s.1 The publication appeared in What Is This Box? A QR Code is a matrix barcode readable by QR scanners, mobile phones with cameras, and smartphones. The QR Code links to the online version of the article.
From the Army Dental Centre, Research and Referral Hospital, New Delhi, India. Received April 24, 2013. Accepted for publication January 7, 2014. Address correspondence and reprint requests to Gaurav Dua, BDS, Army Dental Centre (R&R), Delhi, New Delhi, India; E-mail: [email protected] The authors report no conflicts of interest. Copyright © 2014 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000000735
746
Russian language in 1969. A search for literature for first publication on midface distraction for advancement with rigid external device (RED) for hypoplastic maxilla was demonstrated by Raschmeil et al in 1993.2 The DO of maxilla for advancement is considered to be superior to conventional orthognathic surgery in management of severe maxillary deficiency in cleft lip and cleft palate (CLCP) patients.3 DO provides a gradual distraction of maxilla bringing about changes in both vertical and horizontal vectors. The RED device requires a rigid intraoral appliance to apply traction through the dentition to the entire dentoalveolar segment of maxilla after a Le Fort I osteotomy. Distraction carried out is dependent on the kind of osteotomy carried out and whether the distraction is done through the center of rotation of maxilla or above or below this. The center of rotation for maxilla lies just above the premolar roots. Movement of maxilla brought about by keeping the vector parallel to the center of rotation will bring about its horizontal movement only. A bent 3-hole titanium miniplate is kept parallel to this center of rotation if in case only horizontal movement is desired. Cases requiring movement in both vertical and horizontal vectors of the plating system can be kept above or below it. The number of teeth in the maxillary arch also plays an important role in providing sufficient support. In absence of sufficient tooth support, unfavorable maxillary posterior teeth extrusions occur instead of the desired skeletal changes thereby leading to unsatisfactory aesthetic results. The use of DO is a new and predictable method for maxillary bone elongation with new bone formation at the distraction site. In severe maxillary hypoplasia, this offers a viable alternative in which only the hypoplastic maxilla is addressed, although there have been several conflicting reports regarding its efficacy as well as shortcomings and high rate of relapse, and hence there is a need for this technique to be used judiciously and with care.4 Shortcomings and tendency to relapse in such patients have been largely due to the (1) large advances made greater than 1 cm, (2) scarring in CLCP patients due to previous surgeries, and (3) timing of such distractions wherein once maxillary growth may be over, there is some growth potential that still remain in the mandible. Distractions are better in cases of CLCP due to gradual traction forces forming membranous bones along with soft tissue histiogenesis, a necessity in such patients. This soft tissue drape governs the extent of distraction and also the tendency to relapse.
PATIENTS AND METHODS Patients Nine patients with midface deficiency were referred from the Department of Orthodontics, Army Dental Centre, Research and Referral Hospital between January 2008 and July 2011, and were selected for this study (Tables 1 and 2). The mean age of patients was 18.8 years (range 17–22 years). The study group included 6 males and 3 females. Five patients had
The Journal of Craniofacial Surgery • Volume 25, Number 3, May 2014
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
The Journal of Craniofacial Surgery • Volume 25, Number 3, May 2014
Maxillary DO in Cleft Lip and Palate
TABLE 1. Master Chart
NG, nasogastric tube.
unilateral cleft lip and palate and 4 had bilateral cleft lip and palate. The maxillary advancement was planned based on clinical evaluation for aesthetics, occlusion, and cephalometric values (Fig. 1). Rigid external distractor (KLS Martin) (Fig. 2) was used in all cases. Before surgery, a cobalt-chromium intraoral splint with bilateral eyelets at canine region was fabricated and checked for fit and discrepancies. The appliance was cemented using a luting glass ionomer cement (Figs. 3–5). This appliance was used for 2-fold purpose, firstly to act as a holding device to provide anchorage during distraction and secondly as a salvage unit for intraoral dentoalveolar distraction if intranasal distraction fails.
Method Preoperatively, all patients underwent presurgical orthodontics in Department of Orthodontia. Once a stable occlusion was
achieved in the presurgical phase, the patient’s head was shaved and marking for cranial screw was made. This was done bilaterally 2 to 3 cm above the auricle with indelible markers and kept parallel to the Frankfurt horizontal (FH) plane. This marking reduces intraoperative time in placement of the distractor frame. A high-level step maxillary Le Fort I osteotomy was performed keeping it 5 mm away from the roots. The osteotomy was kept standard for all patients, starting at pyriform rim extending backwards and downwards running laterally and posteriorly to zygomatic buttress to end above the maxillary tuberosity (Fig. 6). Nasal septum and lateral nasal walls were osteotomized followed with pterygoid dysjunction with no attempt to downfracture the maxilla. A 2 3 hole titanium miniplate was adapted and fixed at the pyriform rim keeping the medial-most hole free and bent at 45 degrees and the rest fixed with 5-mm Ti screws. Bilaterally, a 26-G wire was bodied into NG tube and fixed to the distractor ports and traction carried out until taut intraoperatively (Figs. 7 and Fig. 8).
TABLE 2. Result Parameters Variables Mean
T1 (Preop)
Midface advancement
11 mm (planned) 46.1 mm 48.6 mm 72.6 deg 82 deg 9 deg 32.8 deg 67.5 deg −15 deg
A-X (sagittal) A-Y (vertical) SNA SNB ANB SN mandibular plane Nasolabial angle Facial convexity angle
T2 (Post-DO) 13.4 mm (achieved) 59.5 mm 51.2 mm 83.3 deg 82 deg 2.2 deg 33.1 deg 84.7 deg 11.2 deg
T3 (1 yr After DO) 11.1 mm (achieved) 57.22 mm 52.3 mm 82.2 deg 82.6 deg 2.4 deg 33.1 deg 84.7 deg 11.2 deg
© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
Mean Final Achieved 2.3 mm (relapse) 11.12 mm 3.7 mm 9.5 deg 0.6 deg 6.5 deg 0.3 deg 17.2 deg 26.2 deg
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The Journal of Craniofacial Surgery • Volume 25, Number 3, May 2014
Dua et al
FIGURE 3. Co-Cr splint fabricated on die stone.
FIGURE 1. Representation of landmarks and constructed lines used to identify craniofacial and dental parameters on lateral cephalometric radiograph. The following points were assessed: N, nasion; S, sella; ANS, anterior nasal spine; PNS, posterior nasal spine; Ptm, pterygomaxillary fissure; A, subspinale; B, supramentale; Mx1, incisal edge of maxillary central incisor; Pg, pogonion; Gn, gnathion; Go, gonion; Me, menton; Mn1, incisal edge of mandibular central incisor; x axis, horizontal reference line—line through nasion rotated 7 degrees upward from sella-nasion line; y axis, vertical reference line—line perpendicular to horizontal reference line through sella.
The distractor frame was fixed onto the outer plate of the cranium keeping it parallel to the FH plane 2 to 3 cm above the pinna and 2 to 3 cm equidistant from the cranium (Figs. 9–16). Post-osteotomy, a latency period of 5 to 7 days was followed. Distraction at the rate of 0.5 mm (12 hourly) for 7 to 12 days was achieved. A consolidation period of 8 to 10 weeks was allowed. Principle governing consolidation at the end of 8 to 10 weeks is based on radiographic bone healing and presence of cortical outline. Radiographs are therefore taken at intervals of (1) start of distraction, (2) immediate post-distraction, (3) immediate postconsolidation, (4) 6-months follow-up, and (5) 1-year follow-up. After consolidation, the 3-hole titanium plate was removed followed by fixation at pyriform rim and zygomatic buttress under GA. This was followed with retention with Delaire reverse-pull head gear/face mask for 3 months. Clinicoradiological follow-up for stability and soft tissue response for 1 year post-distraction was made. Evaluation of lateral cephalograms was carried out at 3 different stages: T1, pre-distraction; T2, immediate post-distraction (on completion of advancement 12–15 days at the rate of 1 mm/day); and T3, 1-year post-distraction follow-up (Figs. 17–19). The landmarks selected were sella (S), center of sella turcica; nasion (N); A point (A), the deepest point in the curved bony outline of maxilla; and B point (B), the most posterior point in the outer contour of the mandibular alveolar process. Reference planes selected were sella-nasion plane (SN), plane representing the anterior cranial base; x axis (horizontal axis), constructed line at 7 degrees relative
FIGURE 4. Co-Cr splint trial.
to the S-N line; y axis (vertical axis), vertical line through sella perpendicular to x axis; and mandibular plane, tangent to the lower border of the mandible. In a total of 27 cephalograms (3 per patient) used, 8 selected variables were measured as skeletal linear measurements, skeletal angular measurements, and soft tissue measurements. Skeletal linear measurements were as follows: A–X, the shortest distance between y axis and A point along x axis indicating the position of maxilla in sagittal plane; and A–Y, the shortest distance between x axis and A point along y axis indicating the position of maxilla in vertical plane. Skeletal angular measurements were as follows: SNA and SNB angles, which denoted the position of the maxilla and mandible in relation to the anterior cranial base, respectively (normal SNA = 82 ± 2 degrees and SNB = 80 ± 2 degrees); ANB denoting the relation of maxilla and mandible to each other (normal 2–4 degrees); and SN mandibular plane denoting the growth pattern of mandible (normal 32 ± 2 degrees). Soft tissue measurements were nasolabial angle (Cm–Sn–Ls) formed between the columella tangent and the upper lip tangent (normal 102 ± 2 degrees) and the angle of facial convexity (G′–Sn–Pg′) formed by the intersection of the soft tissues glabella– subnasale–pogonion (normal −12 ± 4 degrees) (Fig. 1).
RESULTS Changes observed immediately after distraction showed a mean advancement of maxilla by 13.4 mm. A mean of 2.3 mm horizontal relapse was observed 1 year after distraction. All post-distraction changes were stable at 1 year of follow-up and
FIGURE 2. Rigid external distractor (KLS Martin) complete assembly.
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FIGURE 5. Co-Cr splint final cementation with luting glass ionomer cement.
© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
The Journal of Craniofacial Surgery • Volume 25, Number 3, May 2014
FIGURE 6. Le Fort I osteotomy cut.
Maxillary DO in Cleft Lip and Palate
FIGURE 8. Braided 26 G wire passed through the medial hole and through the nostrils.
the relapse was not significant. Bone formation at the pterygomaxillary region was noted in the study. Post-consolidation cusp fossa occlusion was maintained in all cases. A significant reduction in the facial concavity by 26.1 degrees, anterior movement of upper lip, and improvement of the nasolabial angle by 17.2 degrees was observed.
DISCUSSION Cleft lip and palate is a common congenital defect among developing countries. This is associated with speech problems, dental defects, and psychosocial restrictions, and presents with maxillary hypoplasia. Studies estimate that 25% to 50% of all patients with cleft lip and palate need maxillary advancement.5,6 Cleft patients are difficult to treat with traditional surgical/orthodontic approach.7 Current surgical/orthodontic protocols rely on Le Fort I maxillary advancement. The palatal scarring resists acute advancement and causes relapse. Traditional maxillary surgeries in cleft patients have reported 25% relapse after a mean 7.8 mm advancement.8 Severe cases may also require mandibular set back surgery. The drawback of this bi-jaw approach compromises the final lower facial balance and harmony. The age in which these surgeries can be carried
FIGURE 7. Adaptation of 2 3 hole miniplate with 5-mm Ti screws leaving the medial-most hole.
FIGURE 9. Preoperative frontal view.
out is limited. Orthopedic appliances used to correct maxillary deformity during growing age only camouflage the skeletal discrepancy.9 DO overcomes most of the problems associated with conventional surgery, can be done at any age with fewer complications, and is a better choice for cleft patients as the gradual traction force causes the formation of membranous bone and eliminates the need for bone grafting and donor-site morbidity.9,10 It also allows the growth of soft tissue, which yields longterm aesthetic facial balance. Rigid external distractor system is effective for maxillary hypoplasia in these patients. In a review of literature, the most common modes for distraction included 26 G braided wire looped thru a hole made lateral to pyriform rim or wires looped through the intraoral splint eyelets. These techniques were invariably not parallel to the center of rotation of maxilla thereby causing an open bite postoperatively. Also, these have a disadvantage
FIGURE 10. Preoperative occlusal.
© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
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The Journal of Craniofacial Surgery • Volume 25, Number 3, May 2014
Dua et al
FIGURE 11. Preoperative lateral occlusal.
FIGURE 15. Postoperative lateral profile.
FIGURE 12. Occlusal cleft.
FIGURE 13. Splint cemented.
FIGURE 14. Postoperative frontal profile.
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of bone cut through and cessation of distraction and ultimately relying on intraoral splint for dentoalveolar segment distraction. In our study, the technique of using a 3-hole miniplate was used. The plates were fixed using 2 5 mm Ti screws lateral to pyriform margin bilaterally and keeping the medial-most hole free and bent at 45 degrees to receive the 26 G braided wire. The adaptation of the plates was made parallel to the center of rotation of maxilla avoiding a postoperative open bite, deep bite, and reduction in maxillary alveolar bone height with adequate bone stock regenerate in posterior segment parallel to and in line with the distracted maxilla (Figs. 17–19). All these were evaluated postoperatively and a 1-year review conducted using lateral cephalometrics with changes in respect to x axis to point A in millimeters, point ANS to point A vertical in millimeters, and y axis to point PNS. This 26 G braided wire is looped around the medial-most hole, protected with a no. 12 nasogastric feeding tube, and brought out from the nares to be mounted onto the distraction device. Mean 2.3 mm posterior movement at a point was observed 1 year after distraction which measured 16.6% in comparison to 25% to 30% of relapse as seen in other studies. In our cases, common problems encountered were the vector determination and inability to change the vector. The study showed no significant changes in the mandibular position indicating the improved profile and maxillomandibular relation due to increase in the bony maxillary length. Soft tissue changes were corresponding to the hard tissues. The RED changed the concave profile into an aesthetic balanced profile. Extensive research has been carried out on the subject of aesthetic balanced profile for midface hypoplasia. Work by Yaremchuk11 on making concave faces convex is well established. He used alloplastic implants through intraoral and periorbital incisions for augmentation of facial skeleton. Pterygomaxillary region is the area where the surgeon seeks to achieve stability by placement of bone graft.12 Studies show that
FIGURE 16. Postoperative occlusion.
© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
The Journal of Craniofacial Surgery • Volume 25, Number 3, May 2014
Maxillary DO in Cleft Lip and Palate
FIGURE 19. T3 lateral cephalogram.
FIGURE 17. T1 lateral cephalogram.
DO provides a new sound bone in the pterygomaxillary area, providing stability.13 The new tissues are of the same morphology as the basic hard and soft tissues, and are hence stable. There were minimal dental changes 1 year after distraction. This indicated that the soft tissue changes achieved after DO were stable in accordance with the other studies.14 One limitation of this study is that we did not evaluate the quality of regenerate. Use of better and less invasive diagnostic tools such as 3D ultrasound scan reconstruction should be able to provide specific results.15 Studies recommend overcorrection in periods of growth to compensate for further facial growth in the surrounding tissues, particularly the mandible.14 The inability to predict future growth of the associated anatomical structures is crucial for preoperative planning.
CONCLUSIONS Patients with bone stock deficiencies in maxillary hypoplasia secondary to facial clefts present challenges to the surgeon. Maxillary DO permits a near-normal correction of the midface deficiency in cleft patients. In this study, the results achieved were superior to the conventional osteotomies and orthopedics. The cephalometric data showed stability after RED. Further long-term studies are recommended, with a larger sample size, randomized controlled samples, and longer follow-up, to assess the quality of regenerate. In the future, midface DO may benefit
FIGURE 18. T2 lateral cephalogram.
from automated light and continuous distraction. This will liberate patients from protracted distraction sessions and minimize discomfort. The procedure no longer would depend on activation of RED.
REFERENCES 1. Ilizarov GA, Ledyasev VI, Shitin VP. Experimental studies of bone lengthening. Eksp Khir Anesteziol 1969;14:3 2. Rachmeil A, Jackson IT, Potparic Z, et al. Midface advancement in sheep by gradual distraction: a 1 year follow-up study. J Oral Maxillofac Surg 1995;53:525–9 3. 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;8:181–185 4. Chin M, Toth BA. Distraction osteogenesis in maxillofacial surgery using internal devices: review of five cases. J Oral Maxillofac Surg 1996;54:45–53 5. Molina F. Distraction osteogenesis for the cleft lip and palate patient. Clin Plast Surg 2004;31:291–302 6. Swennen G, Dujardin T, Goris A, et al. Maxillary distraction osteogenesis: a method with skeletal anchorage. J Craniofac Surg 2000;11:120–127 7. McCance AM, Moss JP, Fright WR, et al. Three-dimensional analysis techniques—part 1. Three-dimensional soft-tissue analysis of 24 adult cleft palate patients following Le Fort I maxillary advancement: a preliminary report. Cleft Palate Craniofac J 1997;34:36–45 8. Hochban W, Ganss C, Austermann KH. Long-term results after maxillary advancement in patients with clefts. Cleft Palate Craniofac J 1993;30:237–243 9. Cope JB, Samchukov ML. Mandibular distraction osteogenesis: a historic perspective and future directions. Am J Orthod Dentofacial Orthop 1999;115:448–460 10. Figueroa AA, Polley JW. Management of severe cleft maxillary deficiency with distraction osteogenesis: procedure and results. Plast Reconstr Surg 1998;102:1360–1372 11. Yaremchuk MJ. Making concave faces convex. Aesth Plast Surg 2005;29:141–147 12. Sandor GK, Ylikontiola LP, Serlo W, et al. Midfacial distraction osteogenesis. Atlas Oral Maxillofac Surg Clin North Am 2008;16:249–272 13. Kusnoto B, Figueroa AA, Polley JW. Radiographic evaluation of bone formation in the pterygoid region after maxillary distraction with a rigid external distraction (RED) device. J Oral Maxillofac Surg 2000;58:959–969 14. Wiltfang J, Hirschfelder U, Neukam FW, et al. Long-term results of distraction osteogenesis of the maxilla and midface. Br J Oral Maxillofac Surg 2002;40:473–479 15. Hughes CW, Williams RW, Bradley M, et al. Ultrasound monitoring of distraction osteogenesis. Br J Oral Maxillofac Surg 2003;41:256–258
© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
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