Reconstruction of residual alveolar cleft defects with one-stage mandibular bone grafts and osseointegrated implants

PURPOSE: This study evaluates a treatment regimen for reconstruction of residual maxillary alveolar cleft defects consisting of mandibular bone grafting and immediate implant installation. PATIENTS AND METHODS: Sixteen cleft patients (five female and 11 male) had residual cleft defects of the alveolar ridge reconstructed with bone grafts from the mandibular symphyseal region. The bone graft was pretapped at the donor site before fixation in the residual ridge with Br?nemark implants. Twenty implants were installed according to this concept. The period of observation ranged from 36 to 69 months, with a mean of 48 months after implant installation. RESULTS: Five patients developed wound dehiscenses that resulted in total or partial bone graft sequestration. Two implants were lost, one due to sequestration and the other due to mobility at the abutment procedure; 18 implants were still well functioning at the end of the observation period. However, all patients showed significant periimplant bone resorption after this one-stage treatment. CONCLUSION: Because of the observed complication rate, the one-stage procedure may not be optimal for reconstructing residual cleft defects.     

Bone grafting at the stage of mixed and permanent dentition in patients with clefts of the lip and primary palate

Secondary bone grafting of a residual alveolar cleft has become a well established procedure. However, little attention has been paid to the benefits of these bone grafts in patients with clefts of the lip and alveolus only. This retrospective and comparative study includes 21 patients who had received a secondary or a late secondary bone grafting procedure from tibia and whose mean clinical and radiographic follow-up after the bone graft was 5.5 years. Eighteen patients treated without bone grafting served as controls. Length and width of cleft, presence or absence of permanent lateral incisor, size of nasal floor bony defect, and interdental alveolar bony height in the cleft area were investigated. The results showed that bone grafting was indicated particularly in wide clefts with missing lateral incisors. Eruption of a tooth close to the cleft was facilitated and the bony support for teeth neighboring the cleft was improved. In some cases, additional support of the alar base of the nose was achieved and closure of an oronasal fistula facilitated. A further advantage of bone grafting of clefts of the primary palate was that it might make it possible to insert a titanium implant carrying an artificial tooth in the cleft area.     

Endosseous implants for prosthetic rehabilitation in bone grafted alveolar clefts

The authors report their experience in the surgical and prosthetic rehabilitation of three patients affected by sequelae of cleft lip and palate, with residual alveolar cleft and absence of maxillary anterior teeth. The patients were treated by means of late secondary bone grafting of the alveolar cleft, followed by the insertion of endosseous titanium plasma-sprayed implants (IMZ). After a further healing period (6-12 months) fixed dental prostheses were constructed. Preliminary results from this series have shown how dental prostheses supported by endosseous implants in grafted alveolar clefts are a very reliable possibility in dental rehabilitation of this malformation.     

Implant reconstruction of the jaws and craniofacial skeleton

Full oral rehabilitation with a high degree of success is now possible with osseointegrated implants. Osseointegration is a direct connection between living bone and the titanium implant at the level of the light microscope. Osseointegrated implants are currently used to replace single teeth, support fixed bridges and stabilize full dentures. These implants can also be placed extraorally for attachment of facial prosthesis. The surgical technique used to place implants intraorally into jaws or facial skeleton is performed in two stages using a local anesthetic and/or conscious sedation. During stage I surgery, holes are placed into the jaw using a series of gradually larger diameter burs until the desired diameter and depth of the bony preparation is achieved. The implant is then placed. The implant must remain undisturbed for 4 months for osseointegration to take place. Stage II surgery is then required to remove the mucosa over the implant and place the transmucosal abutment. After 1-2 weeks of healing, the restorative dentist can take an impression and fabricate the prosthesis. On occasion, it is necessary to augment the height and width of the atrophic jaw with autogenous or allogeneic bone grafts prior to implant placement. Bone grafts are sometimes placed on the floor of the nose or the floor of the maxillary sinus. Guided tissue regeneration is a technique used to generate bone within bony defects adjacent to implants. With long-term rates of success (5 years) of 99% for implants placed in the mandible and 95% for those placed in the maxilla, reconstruction of the jaws and cranial facial skeleton with osseointegrated implants has become the treatment of choice.     

Endosseous implant and autogenous bone graft reconstruction of mandibular discontinuity: a 12-year longitudinal study of 31 patients

Surgical, medical, and prosthodontic records of 61 consecutively treated patients with mandibular discontinuity were reviewed retrospectively. All 61 patients had undergone discontinuity reconstruction with autogenous bone grafts; 31 of 61 had also received endosseous dental implants and a dental osseoprosthesis. Of these 31 implant-reconstructed patients, 23 had free autogenous nonvascularized and 8 had vascularized bone grafts. The surgical-prosthetic protocol consisted primarily of secondary, free autogenous nonvascularized bone graft reconstruction and secondary root-form endosseous implant and fixed prosthesis dental reconstruction. Vascularized bone (8 patients) or soft tissue (4 patients) grafts were utilized selectively for severely compromised patients after extensive oncologic resection, avulsive trauma, or after previous radiation treatment. Endosseous implant survival (95.5% in 31 patients), autogenous bone graft success (98.4% in 61 patients), and dental osseoprosthesis success (100% in 31 patients) were favorable. A high incidence (9.1%) of nonfunctioning (sleeping) implants was recorded for this patient population. The need to remove the titanium mesh tray for various reasons (17.6%) and the need to reconstruct soft tissue in the irradiated patient (12%) were noteworthy.     

Alveolar bone grafting in unilateral complete cleft lip and palate patients

Autogenous bone graft of an alveolar cleft area has the following advantages: (1) assistance in the closure of buccoalveolar oronasal fistula; (2) provision of bony support for unerupted teeth and teeth adjacent to the cleft; (3) formation of a continuous alveolar ridge to facilitate orthodontic correction of malocclusion; (4) supporting the nostril floor and alar base to improve nasal aesthetics. It has been well accepted in most craniofacial centers as routine procedure in cleft lip and palate rehabilitation. A new surgical technique for alveolar bone grafting has been introduced to the Chang Gung Craniofacial Center since July 1991. It provided a good exposure of the alveolar cleft, primary closure of the fistula and adequate volume of bone graft. A review of 27 consecutive alveolar bone grafting procedures performed in unilateral cleft lip and palate patients from July 1991 to June 1992 was presented. Patients have been followed up for at least 6 months. The alveolar bone graft was evaluated clinically and radiologically at one week, six months and one year after the surgery. The preliminary results indicated that the new surgical technique produced less chance of recurrent fistula, good postoperative gingival height, and improvement of nasal aesthetics. Based on the results of this new study we strongly advocate the use of this new surgical technique.     

Interpositional bone grafting technique to widen narrow maxillary ridge

A narrow edentulous alveolar ridge, less than 6 mm in the buccopalatal aspect, can prevent restoration by means of endosseous implants. A widening technique using alveolar ridge splitting and interpositional autogenous bone grafting is described. Accurate imaging of the alveolar bone shape and size was assessed with computerized tomography in a 1:1 scale. Following 6 months of healing, osseointegrated Br?nemark implants were placed in the grafted sites.     

Primary insertion of osseointegrated dental implants into fibula osteoseptocutaneous free flap for mandible reconstruction

Twelve patients with segmental mandibular defects were reconstructed with fibula osteoseptocutaneous flaps and simultaneous placement of osseointegrated implants. Decision to perform this procedure was based on the facts that all patients had benign diseases, did not require postoperative radiotherapy, were in good general and oral conditions, and were psychologically motivated. A total of 34 fixtures was inserted in the first stage. Eight patients underwent second stage surgery, which consisted of connection of the implant abutments to the fixtures and the use of palatal mucosal grafts around the implants. Final dental prostheses were fixed 1 month later in seven patients, at this time. All flaps survived after surgery, and no implant failure was observed after a mean follow-up period of 25 months. Only one fixture was not used during the subsequent stage and was left as a sleeper. Fixed dental prostheses were used in five patients and removable overlay prostheses in the other two. Chewing function was recovered between 4 and 6 weeks after the start using the definitive dental prosthesis. In contrast to previous results, we conclude that excellent results can be achieved when this combined procedure is used in carefully selected patients. In addition, it is confirmed that the fibula osteoseptocutaneous flap is a versatile, reliable composite tissue that facilitates primary placement of osseointegrated dental implants during mandible reconstruction, thus allowing full oral rehabilitation in a shorter period of time.     

Reconstruction of an atrophic edentulous maxilla with unilateral cleft lip and palate (UCLP) using sub-antral augmentation and osseointegrated implants: case report and 3-year follow-up

With the current sophisticated, multidisciplinary approach to the treatment of cleft palate, it is anticipated that most patients with this deformity will enjoy good dental health and function. However, due to the number of older adults who were not treated with primary bone grafting and orthodontic therapy, there remains a significant number of potential candidates who may benefit from dental implants and implant-supported prostheses. Although it was not necessary in this case, a pharyngeal extension may be added to the maxillary denture to further improve speech and deglutition. This case report presents a three-year follow-up of a complex reconstruction of a highly compromised, edentulous patient. Stable fixation of the maxillary prosthesis results in a complete return to function in an individual for whom traditional dental prosthetics had resulted in ten years of failure and frustration. Combining the disciplines of reconstructive surgery and implant prosthetics enables the clinician to achieve a predictable result (Figures 12 and 13). While this case represents an extreme example, there are millions of patients for whom implant dentistry can provide life-changing benefits.     

Tripodal mandibular subperiosteal implant: basic sciences, operational procedures, and clinical data

A tripodal mandibular subperiosteal dental implant is a three piece cast metal framework that fits on the residual ridge beneath the periosteum and provides support for a dental prosthesis by means of posts or other mechanisms protruding through the oral mucosa. This implant is indicated in patients with advanced atrophy of the mandible where the unstable alveolar bone has completely disappeared, leaving in place the more stable basal bone with specific anatomical contours. The authors present their experience of 317 cases carried out in three different centers related to this implant modality and underline the importance of the basic anatomic, physiologic, and medical knowledge required to optimize the results.     

An evaluation of measures of synonymous codon usage bias

OBJECTIVE: The aim of this study was to determine whether bone quality, as assessed by osteometry and histologic parameters, can be used to predict implant integration in conjunction with maxillary sinus reconstruction. STUDY DESIGN: Twelve patients with severely atrophied maxillary alveolar processes were treated through use of a two-stage surgical reconstructive strategy with implant placement 4 months after bone grafting. Bone biopsy specimens taken from the iliac crest peroperatively and from the sinus inlay sites 1, 2, 4, 6, or 12 months postoperatively were analyzed by light microscopy and osteomorphometry. Bone mineral content was measured by osteometry. RESULTS: Osteometric and osteomorphometric data (trabecular bone volume [%], assessment of chromatin staining, and an osteocyte index) registered for the biopsy specimens were not statistically correlated with implant failure. CONCLUSIONS: Prognostic evaluation of implant survival is difficult. The tested methods did not contribute to the improvement of guidelines for the clinical handling of these patients.     

Long-term evaluation of the use of coralline hydroxyapatite in orthognathic surgery

PURPOSE: This prospective study was designed to evaluate the long-term clinical and radiographic results of porous block hydroxyapatite (PBHA) used as a synthetic bone graft in orthognathic surgery and craniofacial augmentation. PATIENTS AND MATERIALS: A total of 245 consecutive patients were treated initially. Inclusion criteria for this study included a minimum clinical and radiographic follow-up of 5 years. In addition, all patients with known implant failures were included regardless of whether they met the study criteria. There were 111 patients that met the criteria for inclusion in this study. All patients had undergone orthognathic surgery with rigid fixation and had had inlay or onlay PBHA implants placed. Ninety-six percent of the implants were placed through an intraoral approach. Long-term postoperative radiographs were visually compared with immediate postoperative radiographs for implant position, stability, resorption, and other significant radiographic changes. The clinical examination evaluated for signs and symptoms of infection, wound dehiscence, implant exposure, implant displacement, changes in the overlying mucosa, and development of oronasal or oroantral fistulae. RESULTS: Four hundred seventy-one implants were placed: 403 in the maxilla, 44 in the mandible, and 24 in the periorbital region. There were 289 implants placed in direct communication with the maxillary sinus. The average follow-up time was 7.2 years (range, 5.0 to 10.3 years). Twenty-three implants (4.9%) were removed during the evaluation period. Lateral maxillary wall grafting had 95.7% success, with nine implants being lost in three patients. One chin implant was removed because of dissatisfaction with the aesthetics. Seven (14%) midpalatal implants used for maxillary expansion were lost, primarily because of exposure of the implant to the oral or nasal cavity at the time of surgery. When PBHA was used for alveolar cleft grafting, there was a 100% failure rate. CONCLUSION: The use of PBHA as a bone graft substitute in orthognathic surgery and for facial augmentation showed a high percentage of success and efficacy. However, adequate soft tissue coverage in the nasal floor and on the palate are paramount for success of midpalatal implants. PBHA should not be used for alveolar cleft grafting. Rigid fixation for inlay implants in the maxilla is important to provide stress shielding of the material and minimize micromovement during the initial healing phase.     

Rehabilitation of patients with severely resorbed maxillae by means of implants with or without bone grafts. A 1-year follow-up study

Forty-three patients with severely resorbed maxillae who had been referred for implant treatment were assigned to one of three treatment groups: bone grafting and implant placement (graft group); modified implant placement but no bone grafting (trial group); or optimized complete dentures (no-implant group). Sixteen, 20, and 7 patients, respectively, were assigned to the three groups. At the 1-year follow-up, 10% of the implants had been lost. Only a few of the failures (3/22) occurred after prosthesis placement. The cumulative success rates were 83% in the graft group and 96% in the trial group. A substantial reduction of the grafted bone, especially of the onlay grafts, occurred in many patients. During the period from prosthesis connection to the 1-year follow-up, marginal peri-implant bone loss was on average 0.5 mm. Despite the often demanding procedures involved, all but one patient in each implant group said that they would undergo the treatment again. Most patients were very satisfied with the treatment outcome and their improved masticatory ability. Those who had renounced implant treatment appeared modestly adapted to their optimized dentures, but reported retention problems and less satisfaction with mastication.     

A comparison of vascularized and nonvascularized bone grafts for reconstruction of mandibular continuity defects

PURPOSE: This study compared vascularized and nonvascularized bone grafts for the reconstruction of segmental defects of the mandible. PATIENTS AND METHODS: The results in 39 patients having vascularized bone grafts (38 fibulas and one iliac crest) and 29 patients having nonvascularized bone grafts (26 iliac crest [22 corticocancellous block grafts, four cancellous bone grafts in a tray] and three rib grafts) for segmental mandibular reconstruction were evaluated in terms of overall success rate, total number of surgeries performed, total blood loss, total number of hospital days, and total number of hours in the operating room. RESULTS: Of 39 vascularized bone grafts, two failed (95% success rate), whereas of 29 nonvascularized bone grafts, seven failed (76% success rate). Failure for the nonvascularized bone grafts was closely correlated to the length of the defect. Nonvascularized bone graft patients underwent an average of one more surgical procedure for total reconstruction than vascularized bone graft patients, including osseointegrated implants. However, vascularized bone graft patients spent a mean of over 14 additional days in the hospital for all of their reconstructive procedures and an additional 3 hours in the operating room as compared with nonvascularized bone graft patients. Blood loss was similar in both groups (1,100 mL). Only 20% to 24% of patients in each treatment group have completed reconstruction to include osseointegrated implants. CONCLUSIONS: The success rate for vascularized bone grafting is high and is the treatment of choice when primary reconstruction is required, when the patient has been previously irradiated, or when simultaneous replacement of soft tissue is required. Vascularized bone grafts are also the treatment of choice for mandibular replacements over 9 cm in length. Nonvascularized bone grafts create a better contour and bone volume for facial esthetics and subsequent implant insertion, and may be the treatment of choice for secondary reconstruction of defects less than 9 cm in length.     

Reconstruction of alveolar defects before implant placement

Guided bone regeneration and bone grafting have been used to reconstruct defective alveolar ridges in preparation for implant placement. This phase of implant treatment is critical to a successful overall result. Remarkable advances that have occurred in techniques and materials enable us to place and restore implants in cases where previously it was not feasible. Three case reports are presented to illustrate successful management of different alveolar defects.     

Available bone is the foremost criterion in the insertion of endosteal implants

The foremost criterion in the insertion of endosteal implants is bone availability. Implant dentists should consider first the amount of available bone of the edentulous ridge where the endosteal implant will be inserted. A common error and cause of many implant failures is the dentist's use of an implant modality which is not indicated for the density and morphology of the available bone in the edentulous ridge. Implant modality/system is not the primary criterion in the insertion of endosteal implants. Before the dentist inserts an endosteal implant, he should gauge or measure the amount of bone where the implant is intended to be placed. It should be measured in width, height, length, trajectory, and implant-crown ratio. After recording the measurements of the available bone, these should be placed in different categories to serve as guides in implant selection. If there is not enough bone for the endosteal implant, bone modification should be performed. This can be done either by osteoplasty or ridge augmentation with the use of bone grafting materials. Aside from the amount of available bone in the edentulous ridge, another very, very important thing that should be considered is the quality or its density. Any biocompatible implant demonstrates some osseointegrated surfaces depending upon the bone type into which it is placed and the loads placed upon it. Implant body must exhibit a macrogeometry suitable for acceptable levels of force transfer to the surrounding tissues as well as for implantation into a bony site of a particular anatomic size.     

Functional alveolar ridge reconstruction with prefabricated iliac crest free flap and osseointegrated implants after hemimaxillectomy

We achieved functional alveolar ridge reconstruction after hemimaxillectomy using a prefabricated iliac crest flap. The iliac crest was vascularized secondarily by a long rectus abdominis muscle flap with its inferior epigastric vessels intact to obtain an ideal anatomic location between the maxillary defect and microvascular anastomosis site. The iliac crest was tightly resurfaced with a split-thickness skin graft as well. After a bony surgical delay, the prefabricated iliac crest flap was microsurgically transferred to the face. Three osseointegrated implants were placed in the prefabricated iliac crest, and a dental prosthesis was worn with immobilization and stability. Our procedure enabled recovery of a satisfactory facial appearance and excellent masticatory function.     

The dark side of dioxygen biochemistry

The aim of this study was to evaluate the clinical function and long-term prognosis of overdentures retained by a small number of implants in the maxilla and mandible using one of two different attachment systems. Included in the study were all patients referred to specialty clinics in J?nk?ping and Link?ping, Sweden, during the treatment period who needed an overdenture and could be provided with a minimum number of two bilaterally-placed implants. Excluded were patients with bone-grafted jaws, irradiated cancer patients, heavy bruxers, and patients who had lost a fixed prosthesis because of implant losses. The patients were randomly assigned to receive one retentive system, either a round 2-mm-diameter bar with clips or ball attachments (Nobel Biocare). Eighteen overdentures were placed in maxillae and 32 in mandibles, supported by a total of 115 Br?nemark implants. Of the implants placed, 86.1% were continuously osseointegrated. The cumulative implant survival rates after 7 years of loading were 75.4% in the maxillae and 100% in the mandibles. There was no difference in implant survival rate between the attachment systems. Patients with implant losses were characterized by severely resorbed maxillary ridges and inferior bone quality, together with unfavorable loading circumstances such as short implants combined with long leverages. Complications and prosthetic adjustments were mostly resolved early and easily.     

Ten-year results for Br?nemark implants immediately loaded with fixed prostheses at implant placement

This investigation was initiated to develop a method to provide patients with a fixed provisional prosthesis placed at the time of implant placement. Sixty-three standard 3.75-mm Nobel Biocare implants of varying lengths were placed into mandibular sites in 10 patients and followed for up to 10 years. Twenty-eight implants were immediately loaded at implant placement, providing support for fixed provisional prostheses, while 35 adjacent implants were allowed to heal submerged and stress-free. Following a 3-month healing period, the submerged implants were exposed and definitive reconstruction was accomplished. All 10 prostheses supported by 28 implants placed into immediate function at the time of implant placement were successful during the 3-month healing period. Of these 28 implants placed into immediate function, 4 ultimately failed. Of the 35 submerged implants, all are osseointegrated and in function to date. Life-table analysis demonstrates an overall 10-year survival rate of 93.4% for all implants. The 10-year life-table analysis of survival is 84.7% for immediately loaded implants and 100% for submerged implants. Statistical analysis of the submerged versus immediately loaded implants demonstrates failure rates for immediately loaded implants to be significantly higher (P = .022 by the log rank test). These data demonstrate that although mandibular implants can be successfully placed into immediate function in the short term to support fixed provisional prostheses, long-term prognosis is guarded for those implants placed into immediate function distal to the incisor region.     

The use of the Periotest value as the initial success criteria of an implant: 8-year report

Osseointegration is a histometric process that occurs gradually over a period of time. The load that an implant is able to bear depends upon, among other parameters, the quality of the bone-implant contact. For 8 years the damping capacity of 1,182 Br?nemark implants inserted consecutively in 315 patients was measured using the Periotest method. The following clinical observations were made: (1) a relationship was found between implants with a specific Periotest value range that, at the moment of the transepithelial connection, were considered to be clinically stable, asymptomatic, and whose radiograph image was not radiolucent; (2) a relationship was found between clinically nonintegrated implants with a different Periotest value range; (3) variations in the Periotest value were related to the type of bone in which the implant was placed; (4) a small percentage of borderline implants with a Periotest value between the osseointegrated and the nonosseointegrated Periotest values was detected; (5) the percentage of secondary failures was related to an initial Periotest value corresponding to a borderline implant; (6) the healing time of each implant was individualized in accordance with the successively obtained Periotest value; (7) the load and the design of the prosthesis were individualized; (8) early detection of failing implants before fabrication of prostheses is possible; (9) communication was improved between the surgeon and the prosthodontist; and (10) variations in Periotest value were related to bone remodeling. The sensitivity of the principal clinical test in evaluating osseointegration is discussed regarding the moment of its application. The use of Periotest values as an initial success criteria of an implant is proposed.