Artículo Clínico

---

Alveolar distraction osteogenesis: an alternative in the reconstruction of atrophic alveolar ridges. Report of 10 cases
Distracción osteogénica alveolar: una alternativa en la reconstrucción de rebordes alveolares atróficos. Descripción de 10 casos

 

P.E. Maurette O’Brien, M.E. Allais de Maurette, R. Mazzonetto

---

Abstract: The alveolar distraction osteogenesis is an alternative method for the reconstruction of atrophic alveolar ridges with success, that decrease the time of wait between the reconstruction of the alveolar ridge and the placement of the osseointegrated implants in comparison with the traditionally used methods. 10 patients that presented deficiency of the alveolar ridge in the maxilla and/or mandible were assisted by means of distraction osteogenesis, using a juxtaosseous device (Conexion Implant System® - SP-Brazil). All the patients were assisted of form ambulatory, under local anesthesia and conscientious sedation, beginning the activation from the device 7 days later to the installation, with a pattern of activation 1 mm diary until reaching the wanted bony height. Later on 10 weeks like part of the period of bony consolidation were awaited and one carries out the placement of the osseointegraded implants and the retirement of the distraction device, being able to check clinic and radiographic the gain of the height and necessary bony volume for the rehabilitation by means of implants. Key words: Distraction osteogenesis; Alveolar ridge augmentation; Estability; Osseointegrated implants; Bone atrophy.

Resumen: La distracción osteogénica alveolar (DOA) es un método alternativo para la reconstrucción de rebordes alveolares atróficos que ofrece un resultado previsible y que disminuye los tiempo de espera entre la reconstrucción del reborde alveolar atrófico y la colocación de los implantes óseo-integrados, en comparación con los métodos tradicionalmente utilizados. Fueron atendidos 10 pacientes que presentaban deficiencia de reborde alveolar mandibular y/o maxilar por medio de distracción osteogénica, utilizando un dispositivo yuxtaoseo (Conexión Implant System® - SP-Brasil). Todos los pacientes fueron atendidos de forma ambulatoria, bajo anestesia local y sedación conciente, comenzando la activación del dispositivo a los 7 días posteriores a la instalación, con un patrón de activación de 1 mm diarios hasta alcanzar la altura ósea deseada. Posteriormente se aguardaron 10 semanas como parte del periodo de consolidación ósea y se realizo la colocación de los implantes oseointegrados y local y el retiro del dispositivo de distracción, pudiéndose comprobar clínica y radiográficamente la ganancia de la altura y volumen óseo necesario para la rehabilitación por medio de implantes. Palabras clave: Distracción osteogénica; Aumento de reborde alveolar; Estabilidad; Implantes oseointegrados; Atrofia ósea.

---

1 Odontólogo USM.Caracas -Venezuela. 
Residente del MSc en Cirugía y Traumatología Buco-Maxilo-Facial.
2 Odontólogo, Cirujano Buco-Maxilo-Facial. Profesor Asociado. 
Área de Cirugía y Traumatología Buco-Maxilo-Facial y Director del Curso de Especialización en Implantología
Facultad de Odontología de Piracicaba.Universidad Estadual de Campinas (FOP-Unicamp). Piracicaba-SP-Brasil.

Correspondencia:
Prof. Dr. Remato Mazzonetto.
Universidade Estadual de Campinas.
Faculdade de Odontología de Piracicaba. 
Área de Cirurgia e Traumatologia Buco-Maxilo-Faciais. 
Av. Limeira, 901. Piracicaba. São Paulo. Brasil. CEP: 13414900
E-mail: pmaurette@cirugia-maxilofacial.net

 

Introduction

The techniques traditionally used in patients who present alveolar ridge atrophy in order to achieve adequate bone height for osseointegrated implant placement are mainly based on the use of autogeneous bone grafts1 as well as the use of alloplastic materials.^2,3 In the case of using autogenic bone, its high morbidity rate has been widely described in the literature and bone reabsorption in the region can be expected.^1-3,13

The use of alloplastic materials does not offer us an ideal bed for rehabilitation with osseointegrated implants.^2,3 In addition, all these methods not only do not offer predictable results but also require a waiting time of approximately 6 months between surgery to increase the ridge and the placement of the implants.^1,3

Alveolar distraction osteogenesis (ADO) is a recently introduced method, based on the principles described by Ilizarov,^4,5 who has received the credit for having defined and established the biological bases for the clinical use of osteogenic distraction in the management of different bone deformities. Block et al.^6,7 applied these principles experimentally and was the first to publish studies on the use of ADO in animals in 1996. This same year, Chin and Toth⁸ reported the clinical use of ADO as a treatment in alveolar ridge deficiencies in the upper maxillary. Recently Ukan et al.⁹ and Rachniel et al.³ described the use of ADO by means of interosseous devices (Lead system^®-Leibinger) in the reconstruction of atrophic alveolar ridges. Other reports have described the increase of the ridge by the use of an «Implant-distractor» (Gaggle et al. and Klein et al.).^10,11

The ADO is a method that allows us to augment alveolar ridge height with new bone formation^3,9,12 as well as to obtain a significant increase of the surrounding soft tissues, offering a predictable result, with low morbidity and infection rates and a significantly shorter waiting period for rehabilitation with implants (10 weeks) in comparison with the traditionally used methods.^3,13

In spite of its extended use, there are few clinical reports in the literature that report the use of ADO by means of juxtaosseous devices^14-16 as well as its possible complications and risks. The purpose of this study is to present part of our experience in the use of ADO by means of a yuxtaosseous device developed in Brazil to increase the alveolar ridge and posterior rehabilitation by osseointegrated implants in a sample of 10 patients seen between January to October 2002, evaluating the intraoperative and postoperative complications.

Material and method

Ten patients (7 women and 3 men) who presented alveolar ridge deficiencies were seen in the surgical center of the Odontology School Of Piracicaba – Unicamp. The average age of the group was 31,6 years, all the patients being non-smokers without systemic disorders. Three (3) of the defects were located in the anterior region of the maxillary, 1 defect in the anterior region of the mandible and 6 in the posterior region. The causes of alveolar ridge loss were atrophy after dental extraction, periodontal disease and dento-alveolar traumatisms associated or not to mandible and/or maxillary fractures.

All the patients were seen as out-patients, under local anesthesia (2% Lidocaine solution and epinephrine 1:100.000 IU) and oral conscious sedation (Normonid^®-midazolam). The distractor used was yuxtaosseous type (Implant System^® Connection - SP-Brazil) and fixed to the bone bed by means of 8 mm by 1.5 mm titanium self-tapping screws.

Surgical technique

After the infiltration of local anesthesia, a 5 mm horizontal incision was performed under the alveolar ridge with the elevation of a full thickness flap, exposing the vestibular cortex (Fig. 1).

Two vertical and divergent osteotomies were performed by means of a circular saw with a straight piece and electric motor at 30,000 RPM, under constant irrigation with saline solution, including the vestibular cortex until reaching the medullary bone and were then completed by means of a Wagner straight chisel and Lucas straight chisel. A third horizontal osteotomy was performed apical to the two horizontal cuts, obtaining the transport segment. This segmentary osteotomy was performed adjacent to the teeth that limited the bone defect, respecting the inferior alveolar duct pathway in the mandible. After, the placement of the distractor and its adaptation to the bone surface was performed (Fig. 2). Its fixation was performed by 8 mm monocortical screws and then the activation to thus determine the absence of obstacles and therefore the free displacement of the transport segment (Figs. 3 and 4). The distractor was returned to its initial position and passive repositioning of the flap and synthesis by means of reabsorbable suture 4,0 (Cromic Gut - Ethicon^®) by simple stitches was performed. Post-operative medication was indicated with 750 mg of Paracetamol with a 6/6 hour dosage for 3 days and 25 mg rofecoxib, 12/12 hours for 3 days, in addition to mouth rinsing with chlorexidine gluconate at 0,12% 2 times a day for two weeks, beginning on the 2nd day after the surgery.

A modified version of the protocol described by Hidding et al.¹⁴ was applied in all the patients. Seven (7) days after the placement of the device, the reabsorption of the suture was performed and the patient was instructed on how to perform the activation of the distractor by means of an activation key, following a pattern of 3 daily activations, corresponding to a complete circle of the key (each circle 0,33 mm), the distraction rate being 0,99 mm daily, until the device activation limit was reached. Then there was a 10 week wait for the reabsorption of the distractor (Fig. 5), which was removed under local anesthesia, placing the implants in the same surgical act (Figs. 6-9).

Results

The average bone gain in millimeters achieved in the 10 cases was 7.7 mm (5,3-9,4 mm) (Table 1). Exposure of the device due to suture dehiscence (2 cases) was observed among the main problems found. This was treated with a chlorexidine gel, for healing by second intention. There was no inclination of the transport segment or formation of pseudoarthosis or bone callus in any of the cases. The implants placed presented adequate osseointegration in every case. No evidence of infection or reabsorption in the alveolar ridge was observed in any of the patients seen in the post-operative periods of the first and second surgical phase.

Discussion

The use of ADO in the reconstruction of atrophic alveolar ridges has been shown to be a method that offers increased alveolar ridge height with bone and soft tissue gain, adapting the ridge for posterior rehabilitation of the patient by means of implants, it being a predictable method with low rates of bone absorption, in comparison with the use of bone grafts or alloplastic materials.^3,9,12

In addition, it offers a shorter waiting time between the initial stage and the placement of the implants (10 weeks) in comparison with the 6 months that must usually pass for rehabilitation with implants when autogeneous bone grafts are used.

The main complication found in our study was exposure of the distractor, not observing an inclination of the transport segment toward the lingual one, product of the muscular and soft tissue tension, this being the main complication reported in studies in which intraosseous type distractor was used.^3,9,12 This suggests that the yuxtaosseous type distraction device offers better stability and transport segment guide during the distraction process.

In spite of being a method capable of offering success in regards to the increase in height of the alveolar ridge as well as an increase in the soft tissue level, the ADO is not a substitute for autogeneous bone graft in those cases in which there is deficiency in regards to ridge thickness, it being possible to perform combined procedures of ADO and posterior placement of the autogeneous graft.

Conclusions

We can state that the ADO is a practical and predictable method for reconstruction of alveolar ridges that do not present large transversal deficiencies, having adequate bone height gain as a result in a shorter time, which means a reduction in the treatment time for the patient as well as greater comfort in comparison with other techniques.

References

1. Arx T, von Hardt N, Wallkamm B. The TIME technique: a new technique for localized alveolar ridge augmentation prior to placement of dental implants. Int J Oral Maxillofac Implants 1996;1:387-94.         [ Links ]

2. Caplanis N, Sigurdsson TJ, Rohrer MD, Wikesjö UME. Efect of allogenic, freeze-dried, demineralized bone matrix on guided bone regeneration in supraalveolar peri-implant defects in dogs. Int J Oral Maxillofac Impl 1997;12:634-42.         [ Links ]

3. Rachmiel A, Srouji S, Peled M. Alveolar ridge augmentation by distraction osteogenesis. Int J Oral Maxillofac Surg 2001;30:510-7.         [ Links ]

4. Ilizarov GA. The tension-stress effect on the genesis and growth of tissues. Part I: The influence of stability of fixation and soft-tissue preservation. Clin Orthop 1989;238: 249-81.         [ Links ]

5. Ilizarov GA. The tension-stress effect on the genesis and growth of tissues. Part II: The influence of the rate and frequency of distraction. Clin Orthop 1989;239:263-285.         [ Links ]

6. Block MS, Almerico B, Crawford C, Gardiner D, Chang A. Bone response to functioning implants in dog mandibular alveolar ridges augmented with distraction osteogenesis. Int J Oral Maxillofac Impl 1998;13:342-51.         [ Links ]

7. Block MS, Chang A, Crawford C. Mandibular alveolar ridge augmentation in the dog using distraction osteogenesis. J Oral Maxillofac Surg 1996;54:309-14.         [ Links ]

8. Chin M, Toth B.A. Distraction osteogenesis in maxillofacial surgery using internal devices: Review of five cases. J Oral Maxillofac Surg 1996;54:45-53.         [ Links ]

9. Uckan S, Haydar SG, Dolanmaz D. Alveolar distraction: analysis of 10 cases. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2002;94:561-5.         [ Links ]

10. Gaggl A, Shultes G, Kärcher H. Distraction implants: a new operative technique for alveolar ridge augmentation. J Craniomaxillofac Surg 1999;27:214-21.         [ Links ]

11. Gaggl A, Shultes G, Kärcher H. Distraction implants a new possibility for augmentative treatment of the edentulous. Br J Oral Maxillofac Surg 1999;37:481-5.         [ Links ]

12. García AG, Martín MS, Vila PG, Maceiras JL. Minor complications arising in alveolar Distraction osteogenesis. J Oral Maxillofac Surg 2002;60:496-501.         [ Links ]

13. Oda T, Sawaki Y, Ueda M. Alveolar ridge augmentation by distraction osteogenesis using titanium implants: an experimental study. Int J Oral Maxillofac Surg 1999; 28:151-6.         [ Links ]

14. Hidding J, Lazar F, Zöller JE. Initial outcome of vertical distraction osteogenesis of the atrophic alveolar ridge. Mund Kiefer Gesichtschir 1999;3:79-83.         [ Links ]

15. Klesper B, Lazar F, Hidding J, Zöller JE. Vestical distraction osteogenesis of fibula transplants for mandibular reconstruction – a premilinary study. J Craniomaxillofac Surg 2002;30:280-5.         [ Links ]

16. Carls FR, Sailer HF. Seven years clinical experience with mandibular distraction in children. J Craniomaxillofac Surg 1998;26:197-208.         [ Links ]