J
Oral Maxillofac Surg
49:257-261,1991
Long-Term Follow-up of the Use of Nonporous Hydroxyapatite for Augmentation of the Alveolar Ridge MOHAMED EL DEEB, BDS, MS,* PAUL C. TOMPACH, DDS, BS,t A.T. MORSTAD, DDS, MS,* AND PAUL KWON, DDS, PHD§ Particulate hydroxyapatite (HA) was used in the augmentation of 18 mandibular and four maxillary ridges in 21 patients whose cases were followed postoperatively for 5 to 7 years. Patients were evaluated clinically, radiographically, and through questionnaires. Prosthodontic assessment of retention and stability of dentures showed improvement 5 years postoperatively. Patients receiving HA rated their dentures favorably using parameters of the Cornell Medical Index. The results of this study show that particulate HA alone can be used as a satisfactory material for augmentation of the alveolar ridge.
augmentation of the alveolar ridge.‘je9 Among these materials is hydroxyapatite (HA). Gumaer et al examined the compatibility of HA implanted in canine femurs for up to 8 years. lo Deposition and maturation of bone were noted on the surfaces of both particulate and solid implants. Long-term radiographs indicated completed remodeling of bone, with no resorption of the implanted material except for a few granules in the periosteum associated with multinucleated giant cells. Kent et al originally initiated human clinical trials to examine the clinical use of nonporous particulate HA, with or without autogenous cancellous bone, for augmentation of the alveolar ridge.” Fifty-six patients were followed for up to 4 years. Radiographic evaluation indicated very good to excellent apposition of HA to bone for the majority of these patients. Infiltration of calcified tissue was also noted radiographically and was rated “very good to excellent” in 98% of the cases. No gross migration of implanted particles was noted radiographically in 92% of the cases. Patients’ evaluation of their new dentures, as well as prosthodontic evaluation of the augmented ridges and the dentures, showed excellent improvement in function, retention, and stability in the majority of these patients. No significant decrease in height was noted radiographically up to 4 years postoperatively in patients receiving HA with or without autogenous cancellous bone.” Rothstein et al observed similar successes in clin-
Procedures for augmentation of the alveolar ridge have been performed using both biologic and nonbiologic materials. Biologic materials used have included autogenous grafts or banked bone. Conventional grafting procedures using autogenous bone have usually resulted in significant resorption of the augmented alveolar ridge.le5 Many attempts, therefore, have been made to use alloplastic materials for
* Associate Professor, Division of Oral and Maxillofacial Surgery, Department of Surgical and Diagnostic Sciences, University of Minnesota, Minneapolis. t Second-Year Surgical Resident, Oral and Maxillofacial Surgery, University of Iowa; former undergraduate, University of Minnesota Dental School. $ Professor, Division of Prosthodontics, Department of Restorative Dentistry, University of Minnesota School of Dentistry. § Associate Professor and Chairman, Department of Oral and Maxillofacial Surgery, Marquette University School of Dentistry, WI. Presented at the 70th Annual Scientific Session of The American Association of Oral and Maxillofacial Surgeons, Boston, September 1988. This research was supported in part by grants from Dr and Mrs Ray Peterson, The Sterling Winthrop Research Institute, Rensselaer, NY, and NIH training grant #0709807. Address correspondence and reprint requests to Dr El Deeb: University of Minnesota, School of Dentistry, Department of Oral and Maxillofacial Surgery, 7-174 Moos Tower, 515 Delaware St SE, Minneapolis, MN 55455. 0 1991 American geons
Association
of Oral and Maxillofacial
Sur-
0278-2391 I91 /4903-0007!$3.00/0
257
258
HYDROXYAPATITE FOR AUGMENTATIONOF ALVEOLARRIDGE
ical trials using HA with or without autogenous cancellous bone for augmentation of the alveolar ridge in a multicenter study involving 115 patients. l3 Although only 24 patients were followed for more than 18 months, the initial clinical results indicated that the tissue response was excellent. No infection or resorption of bone was noted beneath the implants, and the reconstructed ridge provided an improved base for support and stabilization of a denture. Only a few complications were noted, mainly regarding the placement and handling of the particulate material. The purpose of this study was to evaluate the long-term clinical use of nonporous HA as a material for augmentation of the alveolar ridge. Materials and Methods SELECTION AND PREOPERATIVEEVALUATION OF PATIENTS Thirty patients were selected on the basis of their need for augmentation of the alveolar ridge and their availability for long-term follow-up. All patients were basically healthy with no serious underlying diseases that could possibly lead to pathologic conditions in the bone. The patients were examined by an oral and maxillofacial surgeon and a prosthodontist prior to surgery. The oral and maxillofacial surgeons evaluated clinical appearance as well as mobility of the overlying soft tissues, radiographic height of alveolar bone, and degree of bone resorption of the alveolar ridge prior to surgery. The prosthodontist assessed the patient’s denture for occlusion, retention, stability, and esthetics. The degree of atrophy in the alveolar ridge was classified on a scale from I to IV, using the criteria developed by Kent and coworkers.” RADIOGRAPHICEVALUATION Panoramic and occlusal film radiographs were taken preoperatively and at 1, 3, 6, 12, 18, and 24 months, and 5, 6, and 7 years. Height of the augmented alveolar ridge was evaluated by visual observation of the serial panoramic radiographs. OPERATIVE PROCEDURE The deficient alveolar ridges were augmented with particulate, nonporous HA (Alveograph, Sterling, Wintrop, NY) in the manner described by Kent and coworkers.”
years or longer. In conducting the postsurgical examination, the oral and maxillofacial surgeon observed the soft tissues and the site of augmentation for signs of inflammation, ulceration, sloughing, sensory loss, migration of the implant, local infection, and healing along the incision line. The surgeon and the prosthodontist examined the preoperative and postoperative radiographs for the following parameters: retention of HA particles in the surgical site, resorption of bone beneath the HA, particulate compaction, and loss of height of the augmentation. Construction of new dentures was initiated when the ridges were determined to be firm by the oral and maxillofacial surgeon and the prosthodontist. Prosthodontic evaluation for retention and stability of the new dentures was determined at all follow-up intervals. A questionnaire concerning satisfaction of the patient that consisted of seven parameters from the modified Cornell Medical Index (comfort, lit of denture, appearance, ability to eat, ability to taste, speech, and general satisfaction) was completed by each patient at the time of each evaluation. All information was recorded on the case records, and comparisons were made from the serial follow-up data. Results PREOPERATIVEEVALUATION Thirty patients initially had augmentation of the alveolar ridge and were monitored for up to 2 years. Seven patients were not available for follow up for the 5-year minimum period and were excluded. Two other patients who received HA and bone grafting to augment their alveolar ridges were also excluded because of the small sample. Twenty-one patients (17 women and 4 men), with 22 augmented ridges (18 mandibular and four maxillary), were evaluated in this study. The mean age of the patients at the time of surgery was 52 years, with a range from 38 to 69 years. The mean postoperative period of observation was 5.3 years, with a range of 5 to 7 years. The average number of edentulous years was 19 and ranged from 3 to 33 years. An average of three previous sets of dentures had been worn, with a range from one to eight sets. Of the 22 ridges augmented with particulate HA, 1 had a class I deticiency, 18 were class II, and 3 were class III. SURGICALAND POSTOPERATIVEINFORMATION
POSTOPERATIVEEVALUATION Postoperative follow-up was carried out for all patients at 1, 3, 6, 12, 18, and 24 months, and at 5
Local anesthesia and intravenous sedation was in an outpatient setting during the treatment of all cases evaluated in this study. A subperiosteal used
ELDEEBETAL
259
tunnel alone was used, with an average of 6 g of particulate HA; the range was from 3 g to 18 g. The particulate HA material was stabilized with a prefabricated surgical stent in 18 ridges; in 7 ridges no stabilization was used. Stabilization was maintained for an average of 7 days (range, 5 to 14 days). Following surgery, all patients were placed on penicillin V, 500 mg four times per day for 10 days. The ridges appeared stable to bimanual palpation in an average of 7 weeks (range, 4 to 12 weeks). Temporary dentures were placed between 5 weeks and 3 months postoperatively (mean, 6 weeks) in all patients. Permanent dentures were placed from 3 to 12 months postoperatively (mean, 6 months) in all patients. COMPLICATIONS Paresthesia of the mental nerve occurred in 6 of the 18 patients who received mandibular HA (33%), with normal sensation returning in all but 3 of the cases (16%). All 3 cases that developed long-term paresthesia were class III atrophic ridges. Immediate dehiscence, within the first 2 to 3 weeks postoperatively, occurred in 5 (23%) of the 22 ridges implanted. All instances of early dehiscence were resolved within the first postoperative month. There was no evidence of delayed dehiscence. Other postoperative complications noted following HA augmentation included slight redness of the overlying mucosa (in 2 patients), displacement of the implant (in 15 patients), and abscess around sutures (in 4 patients). PROSTHODONTICEVALUATION Where HA was used to reconstruct the alveolar ridge, 21 ridges (95%) had been rated preoperatively
FIGURE 2. Photographs showing preoperative and postoperative panoramic radiographs of alveolar ridge augmentation with nonporous HA particulate. Note the minimal compaction that occurred over the years.
by the prosthodontist as poor in regard to stability of dentures, and I8 ridges (80%) had been rated preoperatively by the prosthodontist as poor in relation to retention of dentures. The prosthodontic evaluation at the last follow-up recall (mean, 5
Stability
Retention
100
80
Poor Fair
UJ
FIGURE 1.
Bar graph show-
ing prosthodontic evaluation for stability and retention of the denture before and 60 months after alveolar augmentation with nonporous HA particulate.
E 1 x & z
130
40
$ 20
Pre
60
Pre
Time (months)
60
260
HYDROXYAPATITE FOR AUGMENTATIONOF ALVEOLARRIDGE Discussion
years) showed that 20 patients (90%) had had improvement in retention of their dentures, and all patients had improved with regard to stability of dentures. A comparison between the preoperative and the 60-month postoperative prosthodontic evaluation is shown in Figure 1. The number of relines of dentures placed on ridges augmented with HA ranged from two to four, and the average number of adjustments per denture over the period of this study was four.
Nonporous HA offers many advantages over autogenous bone as a material for augmentation of the alveolar ridge. The material is capable of being placed using only a minor surgical procedure; all patients in this study who received HA were treated in an outpatient setting with local anesthesia and intravenous sedation. None required a vestibuloplasty procedure. Postoperative resorption of autogenous bone grafts without added particulate HA showed loss of ridge area up to 79% after 18 months, as noted by Wang and coworkers.4 Quantitative assessment of the height of ridges augmented with HA in this study was difficult due to the nonstandardized technique used in obtaining the panoramic radiographs. Compaction of the particulate HA usually occurs over time, as is evident from the average number of relines required (three times) and the number of denture adjustments required (four times). Compaction occurs mainly during the early postoperative period. This loss of height due to compaction of the HA, however, was very difficult to verify on the nonstandardized panoramic radiographs. A greater
RADIOGRAPHICEVALUATION Visual evaluation showed no significant loss of height in ridges augmented with HA alone (Fig 2). No resorption of the underlying alveolar bone was observed. EVALUATION
BY PATIENTS USING THE CORNELL MEDICAL INDEX (CMI)
A summary of the patients’ CM1 evaluations before surgery and at 60 months postaugmentation is shown in Figures 3A and B. Taste
Speech
Appearance
Satisfaction
Pre
Pre
80 u) i
60
Iii 0 ‘i;
40
i+J
20
Pre
60
Pre
60
60
60
Tlme (months) Denture Fit
Comfort
Ability to Eat
FIGURE 3.
0
q
Poor Fair
baGood H Excellent
.
Pre
60
Pro
60
Tlme (months)
Pre
60
Bar graphs showing evaluation of CM1 parameters by patients who received augmentations with nonporous HA granules; evaluations reflect before and 60 months after alveolar ridge augmentation.
261
EL DEEB ET AL
loss in augmented area is usually noticed when a mixture of HA and bone is used to augment alveolar ridge. *’ Any displacement of the HA occurred within the first 2 postoperative months. It appeared that once the material was consolidated, further displacement did not occur during the 5- to 7-year period of this study. Displacement of HA granules away from the residual alveolar ridge may have been related to overdissection during creation of the subperiosteal tunnel. An inadequate splint, which can lead to production of excessive force on the HA particles, may also lead to displacement of particles. Desjardins has shown that an improperly constructed splint may force the HA particles laterally if the subperiosteal tunnel extends beyond the borders of the splint. l4 The preaugmentation and long-term postaugmentation evaluation by patients using the CM1 quantitative index appears to indicate that augmentation with HA improves all parameters evaluated. Fluctuations or extreme variations in evaluations were not noted; this may correlate with the fact that most of the settling of the particulate HA material occurs during the first year postoperatively. Prosthodontic assessment of retention and stability of dentures before and after augmentation with HA showed that 90% had improved retention, and all patients had improved stability. Other variations in patients’ evaluations may be attributable to the following: 1) compacting of HA with resultant loss of vertical dimension of occlusion, 2) individual requirements for temporary relines, 3) individual requirements for permanent relines, and 4) stability, retention, and general satisfaction with the denture at the time of examination. In further examining the patients’ evaluations, it is interesting to note the variance expressed by all patients in the parameter concerning taste, a parameter theoretically unaffected by the surgical procedure. This may illustrate the patients’ overall greater satisfaction with their post-
augmentation ridges as compared with their preaugmentation ridges. Acknowledgment The authors recognize the contributions who initiated this study.
of Dr Daniel Waite,
References 1. Fonseca RJ, Clark PJ, Burkes EJ, et al: Revascularization and healing of onlay particulate autologous bone grafts in primates. J Oral Surg 38572, 1980 2. Bird JS, Kullbon TL, Quast GL: Alveolar ridge augmentation with autogenous cancellous bone and marrow graft: Preliminary report. J Oral Surg 32:733, 1974 3. Leake DL: A new alioplastic tray for osseous contour defects. J Maxillofac Surg 2: 146, 1974 4. Wang JH. Waite DE, Steinhauser E: Ridge augmentation: An evaluation and follow-up report. J Oral Surg 34600. 1976 5. Ridley MT, Maxon KG: Resorption of rib graft to inferior border of the mandible. J Oral Surg 36546, 1978 6. Welsh RP. Pillar RM, Macnab I: Surgical implants: The role of surface porosity in fixation to bone and acrylic. J Bone Joint Surg 53:963, 1971 7. Kent JN, Homsy CA, Hinds EC: Proplast in dental facial reconstruction. J Oral Surg 39:347, 1975 8. Nery EB. Lynch KL, Rooney GE: Alveolar ridge augmentation with tricalcium phosphate ceramic. J Prosthetic Dent 40:668, 1978 9. Peterson LJ: Late complications following residual ridge reconstruction with porous hydroxylapatite blocks. Abstract presented at the 68th Annual Meeting of the American Association of Oral and Maxillofacial Surgeons, New Orleans, September 1988 10. Gumaer KI, Sherer AD, Slighter RG: Tissue response in dogs to dense hydroxylapatite implantation in the femur. J Oral Maxillofac Surg 44:618, 1986 11. Kent JN, Quinn JH, Zide MF: Alveolar ridge augmentation using nonresorbable hydroxylapatite with or without autogenous cancellous bone. J Oral Maxillofac Surg 41:629, 1983 12. Block MS, Kent J: Long-term radiographic evaluation of hydroxylapatite-augmented mandibular alveolar ridges. J Oral Maxillofac Surg 42:793, 1984 13. Rothstein SS, Paris DA, Zacek MP: Use of hydroxylapatite for the augmentation of deficient alveolar ridges. J Oral Maxillofac Surg 42:224, 1984 14. Desjardins RP: Hydroxylapatite for alveolar ridge augmentation: Indications and problems. J Prosthet Dent 54:374, 1985
Oral Maxillofac Surg
49:257-261,1991
Long-Term Follow-up of the Use of Nonporous Hydroxyapatite for Augmentation of the Alveolar Ridge MOHAMED EL DEEB, BDS, MS,* PAUL C. TOMPACH, DDS, BS,t A.T. MORSTAD, DDS, MS,* AND PAUL KWON, DDS, PHD§ Particulate hydroxyapatite (HA) was used in the augmentation of 18 mandibular and four maxillary ridges in 21 patients whose cases were followed postoperatively for 5 to 7 years. Patients were evaluated clinically, radiographically, and through questionnaires. Prosthodontic assessment of retention and stability of dentures showed improvement 5 years postoperatively. Patients receiving HA rated their dentures favorably using parameters of the Cornell Medical Index. The results of this study show that particulate HA alone can be used as a satisfactory material for augmentation of the alveolar ridge.
augmentation of the alveolar ridge.‘je9 Among these materials is hydroxyapatite (HA). Gumaer et al examined the compatibility of HA implanted in canine femurs for up to 8 years. lo Deposition and maturation of bone were noted on the surfaces of both particulate and solid implants. Long-term radiographs indicated completed remodeling of bone, with no resorption of the implanted material except for a few granules in the periosteum associated with multinucleated giant cells. Kent et al originally initiated human clinical trials to examine the clinical use of nonporous particulate HA, with or without autogenous cancellous bone, for augmentation of the alveolar ridge.” Fifty-six patients were followed for up to 4 years. Radiographic evaluation indicated very good to excellent apposition of HA to bone for the majority of these patients. Infiltration of calcified tissue was also noted radiographically and was rated “very good to excellent” in 98% of the cases. No gross migration of implanted particles was noted radiographically in 92% of the cases. Patients’ evaluation of their new dentures, as well as prosthodontic evaluation of the augmented ridges and the dentures, showed excellent improvement in function, retention, and stability in the majority of these patients. No significant decrease in height was noted radiographically up to 4 years postoperatively in patients receiving HA with or without autogenous cancellous bone.” Rothstein et al observed similar successes in clin-
Procedures for augmentation of the alveolar ridge have been performed using both biologic and nonbiologic materials. Biologic materials used have included autogenous grafts or banked bone. Conventional grafting procedures using autogenous bone have usually resulted in significant resorption of the augmented alveolar ridge.le5 Many attempts, therefore, have been made to use alloplastic materials for
* Associate Professor, Division of Oral and Maxillofacial Surgery, Department of Surgical and Diagnostic Sciences, University of Minnesota, Minneapolis. t Second-Year Surgical Resident, Oral and Maxillofacial Surgery, University of Iowa; former undergraduate, University of Minnesota Dental School. $ Professor, Division of Prosthodontics, Department of Restorative Dentistry, University of Minnesota School of Dentistry. § Associate Professor and Chairman, Department of Oral and Maxillofacial Surgery, Marquette University School of Dentistry, WI. Presented at the 70th Annual Scientific Session of The American Association of Oral and Maxillofacial Surgeons, Boston, September 1988. This research was supported in part by grants from Dr and Mrs Ray Peterson, The Sterling Winthrop Research Institute, Rensselaer, NY, and NIH training grant #0709807. Address correspondence and reprint requests to Dr El Deeb: University of Minnesota, School of Dentistry, Department of Oral and Maxillofacial Surgery, 7-174 Moos Tower, 515 Delaware St SE, Minneapolis, MN 55455. 0 1991 American geons
Association
of Oral and Maxillofacial
Sur-
0278-2391 I91 /4903-0007!$3.00/0
257
258
HYDROXYAPATITE FOR AUGMENTATIONOF ALVEOLARRIDGE
ical trials using HA with or without autogenous cancellous bone for augmentation of the alveolar ridge in a multicenter study involving 115 patients. l3 Although only 24 patients were followed for more than 18 months, the initial clinical results indicated that the tissue response was excellent. No infection or resorption of bone was noted beneath the implants, and the reconstructed ridge provided an improved base for support and stabilization of a denture. Only a few complications were noted, mainly regarding the placement and handling of the particulate material. The purpose of this study was to evaluate the long-term clinical use of nonporous HA as a material for augmentation of the alveolar ridge. Materials and Methods SELECTION AND PREOPERATIVEEVALUATION OF PATIENTS Thirty patients were selected on the basis of their need for augmentation of the alveolar ridge and their availability for long-term follow-up. All patients were basically healthy with no serious underlying diseases that could possibly lead to pathologic conditions in the bone. The patients were examined by an oral and maxillofacial surgeon and a prosthodontist prior to surgery. The oral and maxillofacial surgeons evaluated clinical appearance as well as mobility of the overlying soft tissues, radiographic height of alveolar bone, and degree of bone resorption of the alveolar ridge prior to surgery. The prosthodontist assessed the patient’s denture for occlusion, retention, stability, and esthetics. The degree of atrophy in the alveolar ridge was classified on a scale from I to IV, using the criteria developed by Kent and coworkers.” RADIOGRAPHICEVALUATION Panoramic and occlusal film radiographs were taken preoperatively and at 1, 3, 6, 12, 18, and 24 months, and 5, 6, and 7 years. Height of the augmented alveolar ridge was evaluated by visual observation of the serial panoramic radiographs. OPERATIVE PROCEDURE The deficient alveolar ridges were augmented with particulate, nonporous HA (Alveograph, Sterling, Wintrop, NY) in the manner described by Kent and coworkers.”
years or longer. In conducting the postsurgical examination, the oral and maxillofacial surgeon observed the soft tissues and the site of augmentation for signs of inflammation, ulceration, sloughing, sensory loss, migration of the implant, local infection, and healing along the incision line. The surgeon and the prosthodontist examined the preoperative and postoperative radiographs for the following parameters: retention of HA particles in the surgical site, resorption of bone beneath the HA, particulate compaction, and loss of height of the augmentation. Construction of new dentures was initiated when the ridges were determined to be firm by the oral and maxillofacial surgeon and the prosthodontist. Prosthodontic evaluation for retention and stability of the new dentures was determined at all follow-up intervals. A questionnaire concerning satisfaction of the patient that consisted of seven parameters from the modified Cornell Medical Index (comfort, lit of denture, appearance, ability to eat, ability to taste, speech, and general satisfaction) was completed by each patient at the time of each evaluation. All information was recorded on the case records, and comparisons were made from the serial follow-up data. Results PREOPERATIVEEVALUATION Thirty patients initially had augmentation of the alveolar ridge and were monitored for up to 2 years. Seven patients were not available for follow up for the 5-year minimum period and were excluded. Two other patients who received HA and bone grafting to augment their alveolar ridges were also excluded because of the small sample. Twenty-one patients (17 women and 4 men), with 22 augmented ridges (18 mandibular and four maxillary), were evaluated in this study. The mean age of the patients at the time of surgery was 52 years, with a range from 38 to 69 years. The mean postoperative period of observation was 5.3 years, with a range of 5 to 7 years. The average number of edentulous years was 19 and ranged from 3 to 33 years. An average of three previous sets of dentures had been worn, with a range from one to eight sets. Of the 22 ridges augmented with particulate HA, 1 had a class I deticiency, 18 were class II, and 3 were class III. SURGICALAND POSTOPERATIVEINFORMATION
POSTOPERATIVEEVALUATION Postoperative follow-up was carried out for all patients at 1, 3, 6, 12, 18, and 24 months, and at 5
Local anesthesia and intravenous sedation was in an outpatient setting during the treatment of all cases evaluated in this study. A subperiosteal used
ELDEEBETAL
259
tunnel alone was used, with an average of 6 g of particulate HA; the range was from 3 g to 18 g. The particulate HA material was stabilized with a prefabricated surgical stent in 18 ridges; in 7 ridges no stabilization was used. Stabilization was maintained for an average of 7 days (range, 5 to 14 days). Following surgery, all patients were placed on penicillin V, 500 mg four times per day for 10 days. The ridges appeared stable to bimanual palpation in an average of 7 weeks (range, 4 to 12 weeks). Temporary dentures were placed between 5 weeks and 3 months postoperatively (mean, 6 weeks) in all patients. Permanent dentures were placed from 3 to 12 months postoperatively (mean, 6 months) in all patients. COMPLICATIONS Paresthesia of the mental nerve occurred in 6 of the 18 patients who received mandibular HA (33%), with normal sensation returning in all but 3 of the cases (16%). All 3 cases that developed long-term paresthesia were class III atrophic ridges. Immediate dehiscence, within the first 2 to 3 weeks postoperatively, occurred in 5 (23%) of the 22 ridges implanted. All instances of early dehiscence were resolved within the first postoperative month. There was no evidence of delayed dehiscence. Other postoperative complications noted following HA augmentation included slight redness of the overlying mucosa (in 2 patients), displacement of the implant (in 15 patients), and abscess around sutures (in 4 patients). PROSTHODONTICEVALUATION Where HA was used to reconstruct the alveolar ridge, 21 ridges (95%) had been rated preoperatively
FIGURE 2. Photographs showing preoperative and postoperative panoramic radiographs of alveolar ridge augmentation with nonporous HA particulate. Note the minimal compaction that occurred over the years.
by the prosthodontist as poor in regard to stability of dentures, and I8 ridges (80%) had been rated preoperatively by the prosthodontist as poor in relation to retention of dentures. The prosthodontic evaluation at the last follow-up recall (mean, 5
Stability
Retention
100
80
Poor Fair
UJ
FIGURE 1.
Bar graph show-
ing prosthodontic evaluation for stability and retention of the denture before and 60 months after alveolar augmentation with nonporous HA particulate.
E 1 x & z
130
40
$ 20
Pre
60
Pre
Time (months)
60
260
HYDROXYAPATITE FOR AUGMENTATIONOF ALVEOLARRIDGE Discussion
years) showed that 20 patients (90%) had had improvement in retention of their dentures, and all patients had improved with regard to stability of dentures. A comparison between the preoperative and the 60-month postoperative prosthodontic evaluation is shown in Figure 1. The number of relines of dentures placed on ridges augmented with HA ranged from two to four, and the average number of adjustments per denture over the period of this study was four.
Nonporous HA offers many advantages over autogenous bone as a material for augmentation of the alveolar ridge. The material is capable of being placed using only a minor surgical procedure; all patients in this study who received HA were treated in an outpatient setting with local anesthesia and intravenous sedation. None required a vestibuloplasty procedure. Postoperative resorption of autogenous bone grafts without added particulate HA showed loss of ridge area up to 79% after 18 months, as noted by Wang and coworkers.4 Quantitative assessment of the height of ridges augmented with HA in this study was difficult due to the nonstandardized technique used in obtaining the panoramic radiographs. Compaction of the particulate HA usually occurs over time, as is evident from the average number of relines required (three times) and the number of denture adjustments required (four times). Compaction occurs mainly during the early postoperative period. This loss of height due to compaction of the HA, however, was very difficult to verify on the nonstandardized panoramic radiographs. A greater
RADIOGRAPHICEVALUATION Visual evaluation showed no significant loss of height in ridges augmented with HA alone (Fig 2). No resorption of the underlying alveolar bone was observed. EVALUATION
BY PATIENTS USING THE CORNELL MEDICAL INDEX (CMI)
A summary of the patients’ CM1 evaluations before surgery and at 60 months postaugmentation is shown in Figures 3A and B. Taste
Speech
Appearance
Satisfaction
Pre
Pre
80 u) i
60
Iii 0 ‘i;
40
i+J
20
Pre
60
Pre
60
60
60
Tlme (months) Denture Fit
Comfort
Ability to Eat
FIGURE 3.
0
q
Poor Fair
baGood H Excellent
.
Pre
60
Pro
60
Tlme (months)
Pre
60
Bar graphs showing evaluation of CM1 parameters by patients who received augmentations with nonporous HA granules; evaluations reflect before and 60 months after alveolar ridge augmentation.
261
EL DEEB ET AL
loss in augmented area is usually noticed when a mixture of HA and bone is used to augment alveolar ridge. *’ Any displacement of the HA occurred within the first 2 postoperative months. It appeared that once the material was consolidated, further displacement did not occur during the 5- to 7-year period of this study. Displacement of HA granules away from the residual alveolar ridge may have been related to overdissection during creation of the subperiosteal tunnel. An inadequate splint, which can lead to production of excessive force on the HA particles, may also lead to displacement of particles. Desjardins has shown that an improperly constructed splint may force the HA particles laterally if the subperiosteal tunnel extends beyond the borders of the splint. l4 The preaugmentation and long-term postaugmentation evaluation by patients using the CM1 quantitative index appears to indicate that augmentation with HA improves all parameters evaluated. Fluctuations or extreme variations in evaluations were not noted; this may correlate with the fact that most of the settling of the particulate HA material occurs during the first year postoperatively. Prosthodontic assessment of retention and stability of dentures before and after augmentation with HA showed that 90% had improved retention, and all patients had improved stability. Other variations in patients’ evaluations may be attributable to the following: 1) compacting of HA with resultant loss of vertical dimension of occlusion, 2) individual requirements for temporary relines, 3) individual requirements for permanent relines, and 4) stability, retention, and general satisfaction with the denture at the time of examination. In further examining the patients’ evaluations, it is interesting to note the variance expressed by all patients in the parameter concerning taste, a parameter theoretically unaffected by the surgical procedure. This may illustrate the patients’ overall greater satisfaction with their post-
augmentation ridges as compared with their preaugmentation ridges. Acknowledgment The authors recognize the contributions who initiated this study.
of Dr Daniel Waite,
References 1. Fonseca RJ, Clark PJ, Burkes EJ, et al: Revascularization and healing of onlay particulate autologous bone grafts in primates. J Oral Surg 38572, 1980 2. Bird JS, Kullbon TL, Quast GL: Alveolar ridge augmentation with autogenous cancellous bone and marrow graft: Preliminary report. J Oral Surg 32:733, 1974 3. Leake DL: A new alioplastic tray for osseous contour defects. J Maxillofac Surg 2: 146, 1974 4. Wang JH. Waite DE, Steinhauser E: Ridge augmentation: An evaluation and follow-up report. J Oral Surg 34600. 1976 5. Ridley MT, Maxon KG: Resorption of rib graft to inferior border of the mandible. J Oral Surg 36546, 1978 6. Welsh RP. Pillar RM, Macnab I: Surgical implants: The role of surface porosity in fixation to bone and acrylic. J Bone Joint Surg 53:963, 1971 7. Kent JN, Homsy CA, Hinds EC: Proplast in dental facial reconstruction. J Oral Surg 39:347, 1975 8. Nery EB. Lynch KL, Rooney GE: Alveolar ridge augmentation with tricalcium phosphate ceramic. J Prosthetic Dent 40:668, 1978 9. Peterson LJ: Late complications following residual ridge reconstruction with porous hydroxylapatite blocks. Abstract presented at the 68th Annual Meeting of the American Association of Oral and Maxillofacial Surgeons, New Orleans, September 1988 10. Gumaer KI, Sherer AD, Slighter RG: Tissue response in dogs to dense hydroxylapatite implantation in the femur. J Oral Maxillofac Surg 44:618, 1986 11. Kent JN, Quinn JH, Zide MF: Alveolar ridge augmentation using nonresorbable hydroxylapatite with or without autogenous cancellous bone. J Oral Maxillofac Surg 41:629, 1983 12. Block MS, Kent J: Long-term radiographic evaluation of hydroxylapatite-augmented mandibular alveolar ridges. J Oral Maxillofac Surg 42:793, 1984 13. Rothstein SS, Paris DA, Zacek MP: Use of hydroxylapatite for the augmentation of deficient alveolar ridges. J Oral Maxillofac Surg 42:224, 1984 14. Desjardins RP: Hydroxylapatite for alveolar ridge augmentation: Indications and problems. J Prosthet Dent 54:374, 1985
