A latency period of several days preceded the phase of active distraction, which is predetermined according to the planned elongation length, or usually around 3 weeks with a twice daily 0.5 mm elongation. We performed a slight overcorrection of 2–3 mm (Fig. 6). Throughout a 16-week consolidation period, weekly follow-ups were performed to prevent postoperative complications and to monitor patient weight and oral hygiene. Afterward, a second surgery was conducted for removal of both internal distractors. The patients then continued orthodontic treatment for postprocedural adjustments. The final step for establishing the patient’s function and esthetics was dental implant supported prosthetic rehabilitation, which was planned in accordance with postsurgical anatomic limitations (Fig. 7). The surgical sequence of treating EEC patients is presented in Table 1.
Demographic and treatment details of the 5 EEC patients who underwent DO in our department are summarized in Table 2.
Hard- and soft-tissue evaluation was carried out by analyzing lateral cephalograms of all patients at 3 successive periods: Preoperative (T1), postdistraction (T2), and 1 year following removal of distraction devices (T3). Four skeletal and 3 soft-tissue reference points were chosen and measurements were recorded as follows: soft-tissue profile was evaluated by Glabella to Subnasale to Pogonion, G’SnPo (angle). The Nasion-Sella line to A point, SNA (angle), and Condylion to A point, CO-A were used to evaluate skeletal changes.
Rambam Health Care Campus Ethics Committee Approval No. 0423-09-RMB.
Written consent of the patient was obtained for publication of the clinical photographs.
All EEC patients in this study demonstrated severe degree of maxillary hypoplasia, accompanied by cleft lip and palate and variable severity of oligodontia. During the period of the study, we treated 5 patients. Three of them were females (60%) and 2 males (40%) with a mean age of 16.8. Average latency and active distraction periods were 4 and 24 days, respectively, and the consolidation phase lasted for 20 weeks on average. Postoperative examination revealed marked maxillary advancement in all our patients (Figs. 7, 8). A Significant mean difference was observed with an increase of 18 mm and 15.2 degrees in maxillary length (Co-A) and SNA, respectively, and an additional improvement in facial convexity (20.9 degrees). Follow-up measurements were performed 12 months following removal of the distraction devices. As shown in Table 3, maxillary length was preserved with only 6% (average, 1.1 mm) posterior relapse. SNA angle was decreased by 2 degrees (13%) and facial convexity was reduced by 3.2 degrees (15.7%).
Two of our patients were monozygotic twins, who had been operated on simultaneously in our institution since infancy. One of them experienced early closure of bone segments and an exposed right distractor during the active distraction phase, which required an immediate surgical intervention to allow mobilization of the maxilla and a new fixation of the intraoral distraction device.
Patients diagnosed with EEC syndrome often present with a severely hypoplastic maxilla with underdeveloped thin alveolar ridges, hypodontia, malformed teeth, and loss of vertical dimension. In this study, we suggest using DO to correct anterior–posterior deficiency resulting from the hypoplastic maxilla in EEC patients, allowing a major elongation and superior stability as compared with traditional orthognathic surgery. Five patients with rare ectodermal dysplasia and cleft lip and palate were treated using this modality in our institution. To our knowledge, this is the first description of EEC patients treated using DO.
A marked advancement of the maxilla and a slight vertical elongation was demonstrated in all patients. Significant improvement in facial profile resulting in a convex appearance was observed in all patients. All our patients were satisfied from the major improvement in facial appearance. The 12-month follow-up data showed stable results regarding skeletal advancement, with a mean horizontal relapse rate of 6% in maxillary length (Co-A) and 13% in SNA angle. This relapse was anticipated due to the major maxillary movement, and thus a slight over correction of 2–3 mm was performed.
These rates are lower than those reported in the literature among nonsyndromic CLP patients treated with orthognathic maxillary advancement in deficiencies of less than 8 mm, compared with our study, which presented a mean horizontal movement of 18 mm.12,13 To our knowledge, there are only few reports in the literature elaborating the treatment of hypoplastic maxilla among EEC syndrome patients. Most of them used the traditional method of Le-Fort I osteotomy to achieve advancement of the maxilla.
Traditionally, advancement of the hypoplastic maxilla, regardless of etiology, is achieved with orthognathic surgery, using a conventional Le-Fort I osteotomy. Worsaae et al.14 described the need for a Le-Fort I advancement in cases of oligodontia associated with EEC.14 Posnick et al.8 and Rachmiel et al.9 have shown limitations of the Le-Fort I osteotomy to include difficult maxilla mobilization due to the formation of postsurgical scarring after cleft lip and palate repair, and high relapse rates. Moreover, large sagittal discrepancies between bony segments place patients at increased risk for velopharyngeal insufficiency.15
In previous works, application of the maxillary DO technique has demonstrated improved stability and greater maxillary advancement due to the slow lengthening and the concomitant bone and soft-tissue formation, as compared with a conventional Le-Fort I procedure.6,16 Among the advantages of this technique are the ability to perform major maxillary movements, stability, less velopharyngeal insufficiency, and an additional elongation of adjacent soft tissues including muscles, nerves, and skin.
In the present study, internal distractors were used. The internal devices are almost invisible and causes less social burden to the patient and therefore allowed for longer consolidation period than the external devices that contribute to the postoperative stability.6,7
A highly important factor during active DO is controlling the vector of elongation to assure the desired positioning of the maxilla at the end of the DO process. Intermaxillary elastics are 1 option to use during the active distraction phase, yet in patients suffering from oligodontia this application is difficult. In our study, temporary anchorage devices were used as an alternative option in patients lacking the sufficient dentition for tooth borne elastics.17–19
In complicated DO procedures, such as in patients with EEC, the use of a computerized tomography designed stereolithographic model allows for presurgical adjustment of the devices and thus immediate and accurate fixation of the internal devices during surgery. Furthermore, the use of custom-made internal devices would allow a much more efficient and accurate advancement with better vector anticipation and thus superior results and fewer complications.
A hypoplastic maxilla has both functional and esthetic consequences in patients, which hamper quality of life and preclude effective dental rehabilitation. We demonstrate that despite challenging anatomic features of EEC patients, there is promising potential for improved appearance, intermaxillary relations, and even dental rehabilitation in patients with ectodermal dysplasia. Further research is required to expand the existing body of knowledge regarding treating severe hypoplastic maxilla using DO.
1. Reed WB, Lopez DA, Landing B. Clinical spectrum of anhidrotic ectodermal dysplasia. Arch Dermatol. 1970;102:134–143.
2. Solomon LM, Keuer EJ. The ectodermal dysplasias. Problems of classification and some newer syndromes. Arch Dermatol. 1980;116:1295–1299.
3. Sharma D, Humar C, Bhalerao S, et al. Ectrodactyly, ectodermal dysplasia, cleft lip, and palate (EEC syndrome) with tetralogy of Fallot: a very rare combination. Front Pediatr. 2015;3:51.
4. Roelfsema NM, Cobben JM. The EEC syndrome: a literature study. Clin Dysmorphol. 1996;5:115–127.
5. Bondarets N, McDonald F. Analysis of the vertical facial form in patients with severe hypodontia. Am J Phys Anthropol. 2000;111:177–184.
6. Rachmiel A, Aizenbud D, Peled M. Long-term results in maxillary deficiency using intraoral devices. Int J Oral Maxillofac Surg. 2005;34:473–479.
7. Combs PD, Harshbarger RJ. Le Fort I maxillary advancement using distraction osteogenesis. Semin Plast Surg. 2014;28:193–198.
8. Posnick JC, Dagys AP. Skeletal stability and relapse patterns after Le Fort I maxillary osteotomy fixed with miniplates: the unilateral cleft lip and palate deformity. Plast Reconstr Surg. 1994;94:924–932.
9. Rachmiel A, Even-Almos M, Aizenbud D. Treatment of maxillary cleft palate: distraction osteogenesis vs. orthognathic surgery. Ann Maxillofac Surg. 2012;2:127–130.
10. Andersen K, Svenstrup M, Pedersen TK, et al. Stability after cleft maxillary distraction osteogenesis or conventional orthognathic surgery. J Oral Maxillofac Res. 2015;6:e2.
11. Bell WH. Le Fort I osteotomy for correction of maxillary deformities. J Oral Surg. 1975;33:412–426.
12. Polley JW, Figueroa AA. Rigid external distraction: its application in cleft maxillary deformities. Plast Reconstr Surg. 1998;102:1360–1372; discussion 1373.
13. Cheung LK, Chua HD, Hägg MB. Cleft maxillary distraction versus orthognathic surgery: clinical morbidities and surgical relapse. Plast Reconstr Surg. 2006;118:996–1008; discussion 1009.
14. Worsaae N, Jensen BN, Holm B, et al. Treatment of severe hypodontia-oligodontia—an interdisciplinary concept. Int J Oral Maxillofac Surg. 2007;36:473–480.
15. Harada K, Ishii Y, Ishii M, et al. Effect of maxillary distraction osteogenesis on velopharyngeal function: a pilot study. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2002;93:538–543.
16. Figueroa AA, Polley JW, Friede H, et al. Long-term skeletal stability after maxillary advancement with distraction osteogenesis using a rigid external distraction device in cleft maxillary deformities. Plast Reconstr Surg. 2004;114:1382–1392; discussion 1393.
17. Aizenbud D, Hazan-Molina H, Cohen M, et al. Combined orthodontic temporary anchorage devices and surgical management of the alveolar ridge augmentation using distraction osteogenesis. J Oral Maxillofac Surg. 2012;70:1815–1826.
18. Rachmiel A, Emodi O, Gutmacher Z, et al. Oral and dental restoration of wide alveolar cleft using distraction osteogenesis and temporary anchorage devices. J Craniomaxillofac Surg. 2013;41:728–734.
Copyright © 2018 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of The American Society of Plastic Surgeons.
19. Shilo D, Emodi O, Aizenbud D, et al. Controlling the vector of distraction osteogenesis in the management of obstructive sleep apnea. Ann Maxillofac Surg. 2016;6:214–218.