Placement of endosteal implants combined with chin bone onlay graft for dental reconstruction in patients with grafted alveolar clefts

Int. Z OralMaxillofac. Surg. 1998;27:440--444 Printed in Denmark. All rightsreserved

Copyright 9 Munksgaard 1998 lntemationalJotn'nalof

Ord Ma.a11 dd Surgery 1SSN 0901-5027

Placement of endosteal implants combined with chin bone onlay graft for dental reconstruction in patients with grafted alveolar clefts

Masayukl Fukuda 1, Tetsu Takahashl 1, Tai Yamaguchl =, Shoko Kochl 3 1Division of Dentistry and Oral Surgery, Akita University School of Medicine, Aklta; =Department of Dentistry and Oral Surgery, National Sendei Hospital, Sendal; SClinics for Maxillo-Oral Disorders, Tohoku University School of Dentistry, Sendal, Japan

M. Fukuda, T. TakahashL T. Yamaguchi, S. Kochi: Placement o f endosteal implants combined with chin bone onlay graft for dental reconstruction in patients with grafted alveolar clefts. Int. J. Oral Maxillofac. Surg. 1998; 27: 440--444. 9 Munksgaard, 1998 Abstract. Endosteal implants were inserted into grafted alveoli after particulate cancellous bone and marrow grafting in seven patients with cleft lip or palate in conjunction with simultaneous chin bone onlay grafting. In these patients, the alveolar bone height of the bony bridge was insufficient when evaluated by both computed tomographic and periapical radiographic images. The age at first implant surgery ranged from 14 to 28 years. Although four of the seven patients had an uneventful course, three had wound dehiscence, and in all but one of them the exposed chin bone underwent partial or total necrosis. Ultimately all seven implants integrated into the bone, and the alveolar bone height was increased in all but one patient. The results indicate that chin bone onlay grafting with simultaneous implant insertion is useful in patients with cleft lip or palate with insufficient alveolar bone height.

A residual alveolar cleft is an obstacle when considering rehabilitation of the dental arch. Secondary bone grafting of the residual alveolar cleft, however, is a well accepted mode of treatment for these patients 1'3,5. Even if bone grafting has been successful, subsequent prosthetic reconstruction using a denture or bridge is necessary because congenitally missing teeth are very often seen in patients with cleft lip and palate (CLP). Recently, implants have been suggested for dental reconstruction in patients with CLP after the repair of the alveolar clefts with autogenous particulate cancellous bone and marrow

Key words: cleft lip and palate; secondary bone graft; endostaal implant; chin bone onlay graft. Accepted for publication 6 June 1998

graft 9,12,14. However, insufficient interdental alveolar bone height seems to be a limiting factor in the clinical use of this procedure. This paper describes the use of chin bone onlay grafting combined with the placement of endosteal implants to reconstruct the grafted alveolar cleft with insufficient alveolar bone height.

Material and methods

The seven subjects were all patients with CLP. Six patients had unilateral CLP (UCLP), and 1 unilateral cleft lip and al-

Fig. 1. Leibinger| Bone Graft Set: Guiding sleeve and trephine.

Endosteal implants with chin bone onlay graft (range, 9.8-27.4 years), and at first implant surgery 19.1 years. The time period from secondary bone grafting to implant placement with chin bone onlay grafting ranged from 0.6 to 10.1 years (mean, 4.6 years). The follow-up period ranged from 2.0 to 5.0 years after implant placement (mean, 3.8 years). Evaluation of the grafted alveoli

Fig, 2. Ins~a-"tionof ttxture tip into mandibular symphysis.

Presurgicat evaluation of the grafted alveoli was performed using computed tomography (CT) and periapical radiography. Vertical bone height and alveolar bone width were calculated from the CT images, and the alveolar boa9 height was estimated and scored using periapical radiographs as reported in a previous study~2. The thickness of the chin bone graft needed was estimated from periapical radiographs. Although the vertical bone height and alveolar bone width were sufficient for implant installation in these seven patients, the alveolar bone height was insuflieient, and the score evaluated as 1 or 2. Surgical technique

veolus (UCLA). Their mean age at the time of secondary bone grafting was 14.5 years

At the grafted alveolus with insufficient alveolar bone height, the gingiva on top of

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the alveolar ridge is incised. Mesially and distally to the alveolus, relief incisions are made buccaHy. A buccal mucoperiosteal flap is raised to expose the nasal floor. The thickness of the chin bone graft needed, i.e. the height from top to bottom of the interdental alveolar bone margin is calculated using calipers. Drilling for implant installation is performed following a surgical protocol, without perforating the nasal mucosa.

In the mandibular symphysis region, a vestibular sulcus incision is made through the mucosa. The periosteum is eL,wated to allow a , hand-driven instrument (Leibinger| FritsehT M Bone Graft Set; Leibinger G-mbH, Freiburg, Germany) to be introduced (Fig. 1). The tip of a self-tapping implant is inserted into the chin bone without penetration of the lingual cortical bone (Fig. 2). The instrument is rotated around the placed implant perpendicularly to the chin bone surface tmtil the labial cortical bone plate has been passed through to the cancellous bone (Fig. 3). The implant and monocortieocancedous bone complex are removed by rotating the instrument (Fig. 4). This complex is then placed at the prepared recipient site, and the implant is inserted in the cortical bone of the nasal

fg-

?

5

Fig. 3. Placement of hand-driven instrument. Fig. 4. Fixture and corticocancellous bone complex. Fig. 5. Clinical appearance after placement of complex.

442

Fukuda et al.

C) P ~ n t i v e ~

~

obtained before bone

graft a n d ~ i m ~ t placemeat. D) ~ ~ after bone graft and implant placement. E) Postoperative ~ radiograph obtained six months after bone graft and implant placement. F) Intraoral view after final prosthetic rehabilitation.

Endosteal implants with chin bone onlay graft

443

Table 1. Demographic and clinical characteristics of the subjects Patiem no.

Sex

1 2 3 4 5 6 7

F F F F M F M

Cleft type

Age at bone grafting (yrs)

Age at first implant surgery (yrs)

Implant site

Score of IABH

Available bone height* (ram)

Fixture length (ram)

Follow-up period (yrs)

UCLP UCLP UCLA UCLP UCLP UCLP UCLP

11.7 11.7 13.4 9.8 15.2 12.2 27.4

18.4 17.8 17.6 20 17.7 14 28

22 22 22 22 22 22 22

2 2 1 2 2 1 1

13.9 12.2 I1.1 15.4 11.5 11.5 10.5

15 13 15 15 13 13 13

5 4.7 4.7 4.4 3.2 2.6 2

* Available vertical height of bone bridge for implant placement was calculated by summation over length on an axial image at more than 4 mm from crest. UCLP=unilateral deft lip and palate. UCLA=unilateral cleft tip and alveolus. IABH =interdental alveolar bone height 12.

Table 2. Change of IABH score Thickness of chin bone (ram)

1

3

2 3

Score Before CBOG

Immediately after CBOG

6 months

1 year

2 years

2

4

3*

3

3

3 5

2 1

3 3

3* 3

3 2

3 2

4

5

2

3

3

3

3

5 6 7

2 5 3

2 1 1

3 3 3

2** 3 3

2 3 3

2 3 3

Patient no.

* Grafted bone underwent partial necrosis. ** Grafted bone underwent total necrosis. IABH=interdental alveolar bone height 12. CBOG=chin bone onlay grafting.

floor (Fig. 5). Small gaps b e t ~ n the complex and the alveolus arc filled with cancellous bone chips obtained from the donor site. The periosteum of the mucopcriosteal flap is incised to aRow this flap to covet the complex without any tension, and the wound is ctose.d. r

naCon { ~ a ~ a t 5t

A girt with UCLA was referred for deft repair and dental reconstruction when she was 12 years old (Fig. 6A). Her maxillary left lateral incisor was congenitally mt~ing. She underwent secondary bone grafting at 13 years of age. After four years of orthodontic treatment she was ready for the final prosthesis (Fig. 6B). We intended to use an implant in the remaining space, but the alveolar bone height was insufficient (Fig. 6C). Chin bone onlay grafting combined with a I5 mm long implant was, therefore, used. The postoperative course was uneventful and the alveolar bone height v~as increased (Fig. 6D)~. Six months later, the implant was tmcover~l, and the excess space was dosed with additional orthodontic treatment (Fig 6E). The prosthetic rehabilitation was completed with a single-unit implant-supported prosthesis (Fig. 6F). Five years after insertion, the implant and crown

are stable, and there arc no clinical or radiographic signs of bone loss.

threads were exposed and the implant is expected to be replaced in the future. Diacuuion

Results A total o f seven implants (one in each patient), all at the left lateral incisor, were placed in bone-grafted alveoli in conjunction with a chin bone graft (Table 1). The score of alveolar bone height before the chin bone graft was 1 or 2. The length of the implant used was 13 or 15 mm, and the thickness of the corticocancellous bone ranged from 2 to 5 mm. The follow-up period ranged from 2.0 to 5.0 years after implant placement with a chin bone graft. Although four of the seven patients had an uneventful course, three had some wound dehiscence and the exposed chin bone underwent partial (patieats 1, 2) or total (patient 5) necrosis (TabIc 2). Ultimately, all seven implants were integrated, and the alveolar bone height had increased in all patients except in patient 5. Although the implant had integrated in patient 5, some

Use o f endosteat implants seems to be a viable option for the dental reconstruction of alveolar clefts. A previous study revealed, however, that some patients, especially those with long periods of time between secondary bone grafting and implant placement, showed significant loss of alveolar bone height 12. Additional bone grafting is, therefore, necessary to augment the bone volume. Onlay grafting provides for appropriate alveolar bone height and width in patients with alveolar local bone defects s,j3. Particulate cancellous bone and marrow grafts seem to have less mechanical strength as compared to corticocancellous bone 6. I n patients with insufficient alveolar bone width, onlay bone grafting should be performed before implantation. The procedure described is effective in that the alveolar bone height may be increased

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Fukuda et al.

simultaneously with insertion of the implant. Guided bone regeneration technique# might also be considered, but these techniques probably do not provide optimal crestal bone height. Some degree of infection and membrane exposure may also be encountered7. Although four of our seven patients bad an uneventful course, three had wound dehiscence, as was also described in the report by PmT~ et al.7. Most patients with CLP underwent several operations in the vestibular region, and wound dehiscence might be due to excessive tension of the gingival scar. Adequate relief incision covering a wide area should be made to prevent possible dehiscence. Alternatively, a free mucosal graft, harvested from the palate, may be an option in preventing wound breakdown. The advantages of the chin as a donor site are related to its anatomic accessibility, minimal morbidity, and absence of vigible scars 6, while resorption of chin bone graft is believed to occur less rapidly when compared to other bone grafts 2,1~ Chin bone has the properties of cortical_bone, providing an immedi-ate physical barrier while functioning as a space maintainer15. The disadvantages of the chin as a donor site are the limited availability of bone and the possibility of damage to the nearby teeth 6. The results reported are encouraging and indicate that chin bone onlay grafting for particulate cancellous bone and marrow grafted alveoli, combined with simultaneous implant insertion is a useful alternative for patients with CLP and insufficient alveolar bone height. The patient selection, however, should be carefully considered. When the alveolar depression co-exists with a para-

nasal depression, the patients might be better treated using a segmental osteotomy to advance the canine, premolars and molars. This provides support for the depressed nasal ala 1]. If no asymmetry exists, the placement of an implant and subsequent fabrication of a crown is to be preferred over a bridge.

References 1. ABYHOLM FE, BImOLANDO, SE~m G. Secondary bone grafting of alveolar clefts: surgical/orthodontic treatment enabling a non-prosthodontic rehabilitation in cleft lip and palate patients. Scand J Plastic Reconstr Surg 1981: 15: 127--40. 2. BORSTLAP WA, I-IE~BUCHEL K_LWM, FREmOFERHPM, KUIJPERS-JAoTMANAM. Early secondary bone grafting of alveolar clefts defects: a comparison between chin and rib grafts. J Craniomaxillofac Surg 1990: 18: 201-5. 3. BORNEPJ, SANDSNR. Secondary bone grafting of residual alveolar and palatal clefts. J Oral Surg 1972: 30: 87-96. 4. BUSER D, DULA H, I-ImTHP, BERTnOLD H. Localized ridge augmentation using guided bone regeneration. In: Bus~t D, DAHLIN C, SCI~NK RK, eds.: Guided bone regeneration in implant dentistry. Tokyo: Quintessence, 1995: 189--234. 5. ENE~RK H, KitAm's-S~oNs~a~ E, SHRAMMJE. Secondary bone grafting in unilateral cleft lip palate patients: indications and treatment procedure. Int J Oral Surg 1985: 14: 2-10. 6. HOPPENRELISTJM, NtrOAMES, FRFaHOFER HPM. The chin as a donor site in early secondary osteoplasty: a retrospective clinical and radiological evaluation. J CraniomaxiUofacSurg 1992:20: 119-24. 7. Pm'ta~E, ALBERIUSP, SAMMANN, LINDE A. Experience with e-PTFE membrane application to bone grafting of cleft maxilia. Int J Oral Maxillofac Surg 1995: 24: 327-32. 8. RAOHOtmARGM, BATm~tmGRHK, VISSINKA, RErtCrSEMAH. Augmentation of

localized defects of the anterior maxillary ridge with autogenous bone before insertion of implants. J Oral Maxillofac Surg 1996: 54: 1180-6. 9. Rostra P, CIm~ASCOP, FRArrn,a CD. Endosseons impiants for prosthetic rehabilitation in bone grafted alveolar clefts. J CraniomaxiUofacSurg 1995: 23: 382~. 10. SINDET-PEDERS~/qS, E ~ H. Reconstruction of alveolar clefts with mandibulax or iliac crest bone grafts: a comparative study. J Oral Maxillofac Surg 1990: 48: 554-60. 11. STOELINGAPJ~, HAERS PEJJ, LEENEN RJ, SOtmRyRJ. Late management of secondarily grafted clefts. Int J Oral Maxillofac Surg 1989: 19: 97-102. 12. TAKAHmmT, FuKtroAM, YAMAGucmT, Kocm S. Use of endosseons implants for dental reconstruction of patients with grafted alveolar clefts. J Oral Maxillofac Surg 1997: 55: 576-83. 13. TOL~t~,NDE. Reconstructive procedures with endosseous implants in grafted bone: a review of the literature. Int J Oral Maxillofac Implants 1995: 10: 275-94. 14. VERDIFJ, LANDIGL, COmgNSR, POWELL R. Use of the Br~memarkimplant in the cleft palate patient. Cleft Palate J 1991: 28: 301-3. 15. WArix PD, ~ TJ, ANUCULB. The stability of maxillary advancement using Le Fort I osteotomy with and without genial bone grafting. Int J Oral MaxiUofac Surg 1996: 25: 264--7.

Address: Masayuki Fukuda Division of Dentistry and Oral Surgery Akita University School of Medicine 1-1-1 Hondo Akita 010-8543 Japan Tel: +81 188 84 6188 Fax: +81 188 84 6451 E-mail: [email protected]