Abstract
The results of a retrospective study on 24 patients who underwent a Le Fort I osteotomy to improve the condition for implant insertion are presented. They all had an edentulous maxilla, Cawood and Howell class VI. Bone grafts were taken from the anterior or posterior iliac crest and implants were placed between 3 and 6 months after the osteotomy. The follow-up period ranged from 5 to 18 years. Initial complications occurred in seven patients in whom small bony defects were present at the time of the implant insertion procedure. The position of the advanced and downward grafted maxilla remained stable over the years. A total of 135 implants were initially inserted, of which 34 failed over the years. Ten implants were inserted to compensate for lost ones, of which only one failed. The screw implants tended to do better than the cylindrical implants. Two patients lost all implants; they had undergone previous surgery affecting the sinus and were also heavy smokers. The remaining 22 patients were satisfied with their treatment as shown by visual analogue scale scores. The results presented are in keeping with those of other reports and underscore the viability of the procedure.
Le Fort I osteotomies for the simultaneous improvement of the intermaxillary relationship and provision of bone volume for implant insertion, have been carried out for almost 20 years. The original idea was put forward by Sailer. He proposed the simultaneous osteotomy and grafting of the gaps with corticocancellous block grafts and insertion of implants. Cawood et al. suggested performing the implant surgery at a later stage in order to allow for bone healing first, whilst it was also claimed that implant insertion would be more accurate, accommodating the preferences of the prosthodontists. This strategy was also followed by Krekmanov, Stoelinga, Isaksson et al., and Nyström et al.
In a study by Stoelinga et al., follow-up of a group of 15 patients for 1–8 years revealed a high implant survival rate and stable advancement of the maxillary fragment without discernible relapse. This was confirmed by other studies.
The purpose of this study was to present the data of a group of 24 patients with a follow-up of 5–18 years, with an emphasis on stability of the reconstructed maxilla, implant survival, complications that occurred over the years, and patient satisfaction. This was a retrospective study on a series of consecutive patients that included the data of the 15 patients reported in the previous article.
Materials and methods
During the period 1991–2004, 25 consecutive patients, seven males and 18 females, aged between 48 and 81 years, were treated in the two participating hospitals. These patients were included in this retrospective study. The early data of 15 patients were reported in a previous study. All patients had an extremely resorbed edentulous maxilla, categorized as class VI according to the Cawood and Howell classification. All patients underwent a two-step procedure: the maxilla was reconstructed first, after which the implants were placed in a second procedure. Eleven out of the 25 patients had a dentate mandible, which was obviously also responsible for the extreme resorption in the maxilla.
All patients received 2,000,000 units of benzyl penicillin intravenously preoperatively and at 2 h after the onset of the operation. Bone grafts were taken from the anterior or posterior iliac crest. A corticocancellous piece was removed from the inner table of the anterior iliac crest measuring approximately 5 cm × 6 cm, after which additional cancellous bone was harvested, as required. When a large forward and downward movement of the down-fractured maxilla was planned and, thus, a larger volume of bone graft was required, a posterior iliac crest graft was taken. The corticocancellous bone was then harvested from the outer surface and the fragment was often larger than 5 cm × 6 cm. At both sites, the wound was closed in layers using 3-0 Vicryl and 5-0 Prolene sutures.
A Le Fort I osteotomy was subsequently carried out to advance and to bring the maxilla down in order to restore the intermaxillary relationship, so as to reduce the vertical intermaxillary distance ( Fig. 1 ). The osteotomies were carried out using a thin reciprocal saw. After down-fracturing, the Schneiderian membrane was carefully removed from the floor of the sinus. Before fixing the fragment in the desired forward and downward position, the sinuses and the nasal cavity were sealed off with cortical bone plates. These plates were shaped to fit the contour of these cavities and were subsequently fixed with 1.5-mm microplates and screws ( Fig. 2 ). The floor of the sinus and the nasal cavities was then packed with a mixture of autogenous particulate bone and hydroxyapatite (HA) granules in a volume ratio of approximately 4–1 ( Fig. 3 ). The presence of the bony roofs allowed adequate condensation of the bone–HA graft, whereas spilling in the nose or sinus was prevented. Platelet rich plasma (PRP) was used in three patients to promote bone healing. The mucosa was sutured with 3-0 Vicryl and the bone grafts were allowed to heal for a period of 3–6 months. The patients were advised not to wear their dentures for a period of 3 weeks after the operation. After this period they were permitted to wear a denture only for cosmetic reasons.
The second step included implant insertion. In almost all cases this was carried out under local anaesthesia in an outpatient setting. The patients were given 4 mg × 500 mg phenoxymethyl penicillin orally for 3 days, commencing 1 h before implant insertion. Prefabricated guidance plates were used for all patients, ensuring optimal implant positioning and maximum parallelism. Each patient received four to eight endosseous implants depending on their prosthetic treatment plan.
A total of 141 implants were initially placed ( Fig. 4 a). Suprastructures were fabricated and implant-borne dentures were placed between 4 and 6 months after implant insertion. Removable overdentures using a ‘bar-clip’ device ( Fig. 4 b) were made for 21 patients with IMZ, Brånemark, ITI-Bonefit, or Frialit implants. Two patients with Screw-Vent implants and one patient with IMZ implants received dentures that were fixed with screws to the suprastructure.
All patients were seen at regular intervals. At the last follow-up they were interviewed with regard to denture function and also asked to assess the function of their dentures before and after reconstruction retrospectively, using a visual analogue scale (VAS) from 1 to 10, with 1 being extremely poor and 10 excellent. The peri-implant condition was registered, and late complications such as small bone defects or sequestration of bone fragments were also recorded. The patients were also questioned about their smoking habits and other confounding factors present during the follow-up period, such as the use of medication, irradiation, or the onset of diabetes. The last follow-up visit took place between 5 and 18 years after the Le Fort I osteotomy.
Standardized cephalometric radiographs and orthopantomograms were taken for all patients preoperatively, immediately postoperatively, 1 year postoperatively, and at last follow-up. Marginal bone levels and the presence of bone loss were assessed both mesial and distal to each implant on the orthopantomograms ( Table 1 ). Implants were assessed clinically using the plaque index and bleeding index at four locations for each implant ( Table 1 ).
| Description of the marginal bone level on a 4-point scale (0–3) | |
| 0 | No apparent bone loss or bone level exceeding ¾ of the implant length |
| 1 | Bone level not exceeding ¾, but exceeding ½ of the implant length |
| 2 | Bone level not exceeding ½, but exceeding ¼ of the implant length |
| 3 | Bone level not exceeding ¼ of the implant length |
| Assessment of plaque accumulation | |
| Score 0 | No detection of plaque |
| Score 1 | Plaque only identified by running a probe across the smooth marginal surface of the implant |
| Score 2 | Plaque can be seen with the naked eye |
| Score 3 | Abundance of soft matter |
| Assessment of bleeding tendency | |
| Score 0 | No bleeding when a periodontal probe is passed along the gingival margin adjacent to the implant |
| Score 1 | Isolated bleeding spots visible |
| Score 2 | Blood forms a confluent red line on the margin |
| Score 3 | Heavy or profuse bleeding |
Maxillary advancement was registered by measuring the angle between the sella–nasion line and the line between nasion and the most anterior part of the maxilla, defined as point A.
Results
Healing after the Le Fort I osteotomy was uneventful in all 25 patients. At implant insertion, however, sinus bony defects with a diameter varying from 5 to 10 mm were observed in seven patients, of whom two had received PRP. In all seven of these patients, the exploration had to be done under local anaesthesia. The defects were enucleated and subsequently grafted with bone harvested from the immediate neighbouring area or distant oral sites. As a result, implant insertion in these patients had to be postponed for another 3 months. No further problems arose, either at the initial implant insertion for the patients without bony defects, or for those who had undergone secondary bone graft procedures.
Implant length varied from 10 to 15 mm in all cases. In all cases, implants were inserted in areas covered by fixed, keratinized mucosa ( Fig. 4 b). No patient required secondary surgery to provide for a fixed mucosa around the implants.
Initially, a total of 141 implants were inserted in 25 patients. One patient, however, experienced pain after the two surgical procedures, which could not be related to the firmly integrated implants. Despite psychological support, she insisted on removal of the six implants before a denture was made. This patient was excluded from the present study. Thus, the study included the follow-up of 24 patients with 135 initially inserted implants. Initial integration in the bone did not occur in three cases. Three new implants were placed within 6 months in these three patients. During the follow-up period, seven more implants were placed because of lost implants. Over the years of follow-up, a total of 34 implants failed after initial integration and one after secondary insertion ( Table 2 ); 101 of 135 implants from first implant placement survived (74.8%) and 9 of 10 from second implant placement survived (90%).
| Number of implants placed | Remaining implants | Survival rate (%) | |
|---|---|---|---|
| First implant placement | 135 | 101 | 74.8 |
| Second implant placement | 10 | 9 | 90.0 |
| Total | 145 | 110 | 75.9 |
Two patients lost all implants, one after 1 year and the other after 10 years. They had both undergone previous surgery involving the maxillary sinuses. One patient had undergone a sinus floor augmentation with cortical block grafts from the skull, which had failed. The other patient had undergone a Le Fort I procedure for which corticocancellous block grafts from the iliac crest had been used, which had also failed. Both patients were also heavy smokers.
Fig. 5 shows the exact data for implant survival over time, as calculated by Kaplan–Meier method. The types of implants used are summarized in Table 3 .
