International Journal of Medical and Dental Case Reports

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Mallik, Singh, Sandhu, and Ramlan:

Anterior maxillary distraction osteogenesis for cleft lip and palate patients - A case series

Pratham Pai, V. M. Nitin, N. Raghunath, Paridhi Gupta

Department of Orthodontics & Dentofacial Orthopedics, JSS Academy of Higher Education and Research, Mysuru, Karnataka, India

Correspondence: Dr. Pratham Pai, JSS Academy of Higher Education and Research, Mysuru, Karnataka, India. E-mail: prats92pai@gmail.com

Received 04 February 2019; Accepted 01 March 2019
doi: 10.15713/ins.ijmdcr.112

Abstract

Distraction osteogenesis (DO) has become a mainstream surgical technique for patients with jaw deformities. This case report describes the surgical orthodontic treatment of maxillary hypoplasia in two patients of 14–19 years with cleft lip and palate. They were treated with anterior maxillary DO using rigid intraoral distractor device. Distraction was started after the initial latency period with activation of 0.8 mm/day until positive overjet was gained. Cephalometric analysis was performed twice for evaluation: Before surgery (Pre-Rx) and after distraction (Post-Rx). Both the distractions completed smoothly and maxilla was distracted efficiently. Maxillary prominence increased in both the patients with a positive overjet after distraction. DO provided an effective way to correct maxillary hypoplasia secondary to cleft lip and palate.

Keywords: Cleft lip and palate, distraction osteogenesis, maxillary deficiency


Introduction

Cleft palate is one of the most prevalent congenital craniofacial birth defects in human. In general, the palatoplasty and pharyngoplasty are performed on such patients at an early age to obtain good velopharyngeal closure.[1] As early as 1954, Herfert suggested that the palatoplasty could damage the growth center of maxilla, thus interfering with the maxillofacial growth, leading to hypoplasia.[2] Bardach and Kelly indicated that severe interference of the maxillary growth usually is caused by the contraction of the scar on the palate.[3]

Recently, distraction osteogenesis (DO) has evolved as a new mainstream surgical technique for patients with such jaw deformities. It can be performed on both the mandible and the maxilla. Maxillary DO was proposed in 1997 using a rigid external distraction device. DO can provide skeletal advancement along with expansion of soft tissue and is regarded as highly effective surgical technique for patients with jaw deformities.[4]

DO has shown excellent results in maintaining stability. DO outweighs the traditional methods of craniofacial reconstruction by its ability to generate new bone and reduced morbidity rate. In addition, advancement by DO is not as limited as conventional osteotomies.[5,6]

Case Report

The study consisted of two female patients of 14–19 years of age. Both patients suffered from cleft lip and palate deformity with a hypoplastic maxilla. The pre-treatment findings of both the patients have been enlisted in Table 1.

Table 1 Intraoral findings of both the cases

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Written informed consent in regional language was obtained from both the patients.

Treatment objective

The objective was to correct the following parameters:

  • Hypoplastic maxilla by forward repositioning

  • Anterior and posterior crossbites

  • Reverse overjet and overbite

  • Molar and canine relationship.

Treatment alternatives

Anterior movement of maxilla by Le Fort 1 orthognathic surgery was an alternative treatment for these cases. However, due to the possibility of aggravation of hypernasality in the patients after Le Fort 1 osteotomy, DO of anterior maxilla was chosen as the treatment plan. The reason is that the velopharyngeal area will remain intact after the anterior DO procedure.

Treatment protocol

Both the patients underwent fixed orthodontics in both upper and lower arch with standard 0.022 pre-adjusted edgewise prescription.

Treatment progression

Case 1 had the presence of deciduous molars between the first permanent molars and first premolars. Extraction of these deciduous molars resulted in gaining adequate space for the vertical cuts required during surgery. Case 2 had both the premolars erupted into the occlusion on one side. As a result, it was required to gain space between the teeth orthodontically. After leveling and alignment, space required for surgical cuts in this case was created using NiTi open coil springs between the premolar and molar.

A day before the surgery both upper and lower alginate impressions were recorded and casts were poured. Bands were fabricated on premolars and molars and hyrax expansion screw was positioned in the palatal region to bring about anteroposterior expansion and was soldered to the bands on the premolars and molars. The fit of the appliance was examined in the patients mouth 1 day before the surgery.

Surgical procedure

Vertical cuts were made between two premolars on either side. Horizontal cuts were made in a fashion similar to that of conventional Le Forte 1 osteotomy in both the cases. Down fracture of the premaxilla was done. After complete mobilization of the premaxilla, the appliance was cemented into the mouth and surgical site was closed using sutures.

Distraction protocol

The distraction procedure was initiated after 5 days of the surgery. The distractor was activated twice per day with two turns per activation giving a total distraction of 0.8 mm/day. Patients were recalled after every 3 days. Distraction was discontinued after attaining the desired overjet. 8 weeks of consolidation period was maintained and hyrax appliance was removed only after callus formation was confirmed on the radiograph. The various cephalometric landmarks used for evaluation of both the cases have been discussed in Table 2.

Table 2 Definitions and implications of cephalometric landmarks

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Results

Both the patients were treated by anterior maxillary osteotomy. Treatment was discontinued after achieving satisfactory overjet and occlusion. The maxillary retrusion facial profile improved, and an acceptable interincisal relationship was obtained [Figures 1 and 2].

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Figure 1 (a and b) Case 2 - Intraoral pre- and post-distraction

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Figure 2 (a and b) Case 1 - Extraoral pre- and post-distraction

SNA increased from 74° to 78° in Case 1 and from 70° to 73° in Case 2. Overjet increased from −5 mm to 2 mm in Case 1 and from 0 to 4 mm in Case 2.

The cephalometric index before and after treatment for both the cases have been provided in Table 3.

Table 3 Cephalometric index before and after DO

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Both cases developed open bite during distraction phase. Improvement in speech of both the patients was noted as described by the clinician, patients, and their parents.

Discussion

Cleft lip and palate patients show sagittal hypoplasia of maxilla and speech disorders. Various reasons are liable for maxillary constriction, such as tension of scars, teeth agenesis, and poorly reconstructed nasolabial muscles.[7] Maxillary DO is often employed for correction of maxillary hypoplasia in patients with cleft lip and palate. The intraoral distractor offers some benefits such as less psychological stress and shorter hospitalization period and does not necessarily require patient’s cooperation during the retention period. As compared to the extraoral distraction, it does not leave scars caused by fixation screws.[8]

This case report demonstrates increase in SNA angle in both the patients following surgery in accordance with maxillary advancement. Alkhouri et al. reported similar findings in patients with unilateral cleft lip and palate.[9] The use of banded type of the anteroposterior expansion might have led to the extrusion of molars as a result of which Y-axis seemed to increase in both the cases after distraction. Similarly, as a result of extrusion of the maxillary molars, there was clockwise rotation of mandible, leading to posterior positioning of Point B seen in both the cases. SN-PP, which represents the inclination of palatal plane, was decreased showing a tendency toward open bite as seen in both the cases clinically. Nv to Point A depicted a decrease in value indicating forward movement of maxilla whereas and Nv to Pog demonstrated an increase in the negative value.

Srivastava et al. reported an increase in U1 to SN value following distraction therapy which was not in correlation with our study as the ongoing orthodontic treatment resulted in retroclination of upper incisors rather than proclination [10] UI to NA angular measurements decreased demonstrating decrease in proclination and the linear measurement also decreased showing the forward movement of Point A following the surgery. There was a significant reduction in overjet of both the patients decreasing their Class III tendency.

Hence, maxillary advancement is essential to improve the esthetic profile and functional occlusal relationship. Many other studies have evaluated the effectiveness of DO in the treatment of cleft lip and palate patients suffering from maxillary deficiency.[11-13]

The pitfall of the surgery is the lack of vector control and development of an anterior open bite.[14]

Conclusion

AMOD is a good therapeutic procedure to relish the esthetic improvement and establish a good occlusal relationship. Its ability to increase the palatal and arch length, preservation of palatopharyngeal closure function, and reduction in the relapse rate, anterior maxillary segmental distraction has great value in the treatment of maxillary hypoplasia secondary to cleft lip and palate.

References

1. Lin X, Zhou N, Huang X, Song S, Li H. Anterior maxillary segmental distraction osteogenesis for treatment of maxillary hypoplasia in patients with repaired cleft palate. J Craniofac Surg 2018;29:e480-4.

2. Herfert O. Experimental contribution to the problem of injury to maxillary growth by premature cleft palate surgery. J Dtsch Zahn Mund Kieferheilkd Zentralbl 1954;20:369-80.

3. Bardach J, Kelly KM. Does interference with mucoperiosteum and palatal bone affect craniofacial growth?An experimental study in beagles. Plast Reconstr Surg 1990;86:1101-2.

4. Mofid MM, Manson PN, Robertson BC, Tufaro AP, Elias JJ, Kolk CA. Craniofacial distraction osteogenesis:A review of 3278 cases. Plast Reconstr Surg 2001;108:1103-14.

5. Polley JW, Figueroa AA. Rigid external distraction:Its application in cleft maxillary deformities. Plast Reconstr Surg 1998;102:1360-74.

6. 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.

7. Tae KC, Gong SG, Min SK, Whan S. Use of distraction osteogenesis in cleft palate patients. Angle Orthod 2003;73:602-7.

8. Kitai N, Kawasaki K, Yasuda Y, Kogo M, Murakami S, Kreiborg S, et al. Rigid external distraction osteogen-esis for a patient with maxillary hypoplasia and oligodontia. Cleft Palate Craniofac J 2003;40:207-13.

9. Alkhouri S, Waite PD, Davis MB, Lamani E, Kau CH. Maxillary distraction osteogenesis in unilateral cleft lip and palate patients with rigid external distraction system. Ann Maxillofac Surg 2017;7:57-63.

10. Srivastava D, Ghassemi A, Ghassemi M, Showkatbakhsh R, Jamilian A. Use of anterior maxillary distraction osteogenesis in two cleft lip and palate patients. Natl J Maxillofac Surg 2015;6:80-3.

11. Chin M, Toth BA. Distraction osteogenesis in maxillofacial surgery using internal devices:Review of five cases. J Oral Maxillofac Surg 1996;54:45-54.

12. Showkatbakhsh R, Pourdanesh F, Jamilian A, Ghorbani A, Behnaz M. Hyrax application as a tooth-borne distractor for maxillary advancement. J Craniofac Surg 2011;22:1361-6.

13. Tate GS, Tharanon W, Sinn DP. Transoral maxillary distraction osteogenesis of an unrepaired bilateral alveolar cleft. J Craniofac Surg 1999;10:369-74.

14. Iida S, Kogo M, Aikawa T, Masuda T, Yoshimura N, Adachi S. Maxillary distraction osteogenesis using the intraoral distractors and the full-covered tooth-supported maxillary splint. J Oral Maxillofac Surg 2007;65:813-7.