DENTAL IMPLANTS
Rehabilitation With Implants After Bone Lid Surgery in the Posterior Mandible Stefano Sivolella, DDS, PhD,* Giulia Brunello, DDS,y Mario Berengo, MD, DDS,z Marleen De Biagi, DDS,x and Christian Bacci, DDS, PhDk Bone defects are often secondary to alveolar disease removal. Creating a bone lid with piezosurgery is a valid method to preserve the alveolar bone. A careful and precise osteotomy associated with a firm placement of the bone lid in its original position enables better bone healing, thus allowing for the delayed insertion of dental implants at the operated site with no need for any bone augmentation procedures. The aim of this technical note is to present the application of the bone lid surgery in the posterior mandible before dental implant rehabilitation. Ó 2015 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 73:1485-1492, 2015 Fashioning a bone lid involves cutting a window and removing a portion of bone, which is subsequently returned to its original position at the end of the surgical procedure. This technique enables large bone defects secondary to access osteotomies to be avoided. It can be used in several clinical situations, such as the accidental displacement of foreign bodies into the maxillary sinus1-3 or to gain access to teeth or alveolar bone lesions.4,5 The removal of lesions, such as cysts or tumors, or impacted teeth from alveolar bone is often associated with residual defects that prevent the use of dental implants without performing augmentation procedures.6,7 In such cases, the ideal treatment is as conservative as possible to preserve alveolar bone. Bone lid osteotomies can be performed with a microsaw,5 a long shank drill,8 or piezosurgery.2-4,9 Before the osteotomy is completed, the bone window can be pre-plated with microplates to ensure the bone lid’s stability after it has been put back in place.2 Alternatively, small holes can be drilled into the lid and the surrounding bone to allow for the lid to be fixed with resorbable sutures. For precise, thin, beveled osteotomies, a bone lid can even be fitted stably and accurately in place without any need for further fixation.5 In a recent prospective study, Khoury5 described 200 consecutive patients treated using the bone lid
approach during pre-implant and implant surgical procedures. In 124 patients the bone lid was put back in place without any simultaneous implant positioning or bone graft procedures, and the mean alveolar crest width was reportedly 7.6 0.8 mm immediately after reimplantation of the bone lid. Three months later, the alveolar crest was substantially well preserved in most cases (mean width, 7.1 1.2 mm). In another 76 patients, the bone lid was returned to its original position simultaneously with implant insertion and, in some cases, with bone augmentation procedures (depending on the adequacy of the bone volume and any evidence of infection) and normal healing without any infection was observed. Jung et al8 treated 10 patients using a modified bone lid technique to remove failed implants. In 3 patients, the implants were replaced immediately. Some changes were made to the original bone lid technique, including the use of grafting materials. The aim of the present technical note is to illustrate, through 2 clinical cases, the value of the bone lid technique in the treatment of posterior mandibular pathologic conditions. Implant-supported prosthetic rehabilitation is possible in spontaneously regenerated bone in the edentulous posterior mandible after the first surgical bone lid procedure.
Received
Padova, Via Giustiniani 1, 35129 Padova, Italy; e-mail: giulia-bru@
from
the
Section
of
Dentistry,
Department
of
Neurosciences, University of Padova, Padova, Italy.
libero.it
*Consultant. yResident.
Received February 9 2015 Accepted March 15 2015
zFull Professor.
Ó 2015 American Association of Oral and Maxillofacial Surgeons
xResident.
0278-2391/15/00342-0
kConsultant.
http://dx.doi.org/10.1016/j.joms.2015.03.050
Address correspondence and reprint requests to Dr Brunello: Section of Dentistry, Department of Neurosciences, University of
1485
1486 The patients were fully informed about their condition and consented to the clinical and surgical procedures, which included taking photographs of the lesions and procedures. The procedures described complied with the World Medical Association Declaration of Helsinki on medical research protocols and ethics.
Report of Cases CASE 1
A healthy 64-year-old male patient presented with an extensive radiolucent lesion in the posterior portion of the left mandible that apparently extended from the roots of an endodontic-treated third molar. The patient was clinically asymptomatic and the lesion was an incidental radiographic finding (Fig 1). After preoperative computed tomography (Fig 2), surgery was performed under local anesthesia and sedation.10 A crestal incision was made within the keratinized gingiva in the edentulous mesial area and extended within the sulcus to left mandibular third molar and a distal releasing incision was made. A mucoperiosteal flap was reflected buccally and the third molar was extracted. Adequate access to the lesion was assured by a buccal bone lid fashioned using a piezoelectric device
CONSERVATIVE BONE LID WITH PIEZOSURGERY
(Piezosurgery, Mectron SpA, Carasco, Italy; insert OT7; Fig 3A). After its removal, the bone lid was placed in sterile saline solution. The pathologic tissue was removed from the surgical site, leaving the inferior alveolar nerve intact (Fig 3B). No filling material was used. The buccal bone lid was returned to its original position and stabilized with 1.3-mm fixation microplates (Synthes GmbH, Oberdorf, Switzerland; Fig 3C). The flap was put back in place and sutured. The histopathologic findings were consistent with a radicular cyst, confirming the clinical and radiologic preoperative diagnosis. One year after removing the cyst, healing and spontaneous filling of the residual cavity were confirmed on postoperative orthopantomogram (Fig 4) and computed tomogram (Fig 5). There were no signs of recurrent cyst. The fixation plates were removed (1 year after their insertion) and 3 1-stage implants (XiVE S, DENTSPLY Friadent, Mannheim, Germany) were inserted using a surgical guide at the same time (Fig 6). The patient was referred back to his dentist for prosthetic rehabilitation. He was fitted with a provisional metal-and-acrylic fixed prosthesis 4 months after implant surgery and with a permanent cemented metal-and-ceramic prosthesis after 10 months (Fig 7A, B). The patient was followed with annual
FIGURE 1. Case 1. Preoperative orthopantomogram shows a roundish well-defined radiolucent lesion apically to the left mandibular third molar. Sivolella et al. Conservative Bone Lid With Piezosurgery. J Oral Maxillofac Surg 2015.
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FIGURE 2. Case 1. Preoperative computed tomogram showing multiplanar reconstructions of an area of left mandibular third molar. The buccal bone is preserved but the mandibular canal is not always recognizable. Sivolella et al. Conservative Bone Lid With Piezosurgery. J Oral Maxillofac Surg 2015.
clinical examinations and radiographs of his implants and prosthetics. CASE 2
A healthy 54-year-old female patient presented with a complaint of impaired masticatory function associated with partial edentulism in the posterior left mandible. A preoperative panoramic radiograph (Fig 8) visualized an unerupted ectopic mandibular premolar in the lower left mandible, which prevented any implant placement in the edentulous ridge. The premolar was extracted under local anesthesia and sedation.10 An adequate full-thickness flap was reflected and the ectopic tooth was accessed through a buccal bone lid fashioned using a piezoelectric device (Piezosurgery; insert OT7; Fig 9A). After removing the bone lid and placing it in sterile saline solution, the tooth was dissected and then extracted, leaving the
inferior alveolar nerve intact (Fig 9B, C). No grafting material was used to fill the cavity. The buccal bone lid was returned to its original position with a 1.5mm fixation microplate (Synthes GmbH; Figs 9D, 10A) and the flap was put back in place and loosely sutured. Four months later, the fixation screws and plate were removed and 2 2-stage implants (Osseotite, Biomet 3i, Palm Beach Gardens, FL) were inserted in the posterior left edentulous mandibular ridge during the same procedure (Fig 10B). After another 4 months, the implants were exposed and the patient was referred to her dentist for permanent, cemented metal-and-ceramic prosthetics (Fig 10C).
Discussion A piezoelectric device used to fashion a bone lid2-4 enables a selective, accurate, thin cutting of hard
1488
CONSERVATIVE BONE LID WITH PIEZOSURGERY
FIGURE 3. Case 1. A, After left mandibular third molar was extracted, the mandibular buccal bone lid was fashioned using piezosurgery. B, Removing the bone lid provided access to the cystic lesion. C, The buccal bone lid was put back in place and fixed with microplates. Sivolella et al. Conservative Bone Lid With Piezosurgery. J Oral Maxillofac Surg 2015.
FIGURE 4. Case 1. Orthopantomographic assessment 1 year after cyst removal. Sivolella et al. Conservative Bone Lid With Piezosurgery. J Oral Maxillofac Surg 2015.
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FIGURE 5. Case 1. Computed tomogram 1 year after surgery clearly shows a complete recovery. Fixation screws are in place and well integrated. The mandibular canal is readily detectable in all reconstructions. Sivolella et al. Conservative Bone Lid With Piezosurgery. J Oral Maxillofac Surg 2015.
tissues, decreases the risk of inferior alveolar nerve damage, limits intraoperative bleeding, and provides a better view of the surgical field.4,11 Using piezosurgery helps to obtain precise, beveled-edge osteotomies, and this facilitates the subsequent embedding of the bone windows. Neither of the present patients complained of any postoperative sensory impairment of the inferior alveolar nerve. Similar results were reported by Degerliyurt et al.4 The time it takes to complete the osteotomy using piezosurgery is comparable to the time taken using conventional instruments.2,12 Khoury5 reported tak-
FIGURE 6. Case 1. Detail of the immediate postoperative orthopantomogram at the time of implant placement and plate removal. Sivolella et al. Conservative Bone Lid With Piezosurgery. J Oral Maxillofac Surg 2015.
ing a shorter time to complete similar procedures using a micro-saw. Kocyigit et al13 compared the use of piezosurgery with conventional surgery for radicular cyst enucleation in the jaw. Nineteen patients were treated using piezosurgery and 10 using conventional rotational burs. No surgical or postoperative complications were observed in the piezosurgery group. No soft tissue damage occurred in the other conventionally treated group, but intraoperative hemorrhage severe enough to interfere with the procedure was reported in 3 cases and manipulation difficulties were encountered in 5 cases, resulting in major cystic epithelial perforation. In this latter group, there also were 2 cases of postoperative hemorrhage and 2 of cyst recurrence. They also reported longer operating times for cyst enucleation using piezosurgery.13 A randomized clinical trial also was conducted to compare piezosurgery with conventional rotatory surgery for mandibular cyst enucleation in 80 patients (40 per group).9 Subjective postoperative pain was recorded daily for 7 days using a visual analog scale and was lower in the piezosurgery group. Patients treated with the piezoelectric technique also had less swelling, a shorter recovery time, and no nerve damage, whereas 2 of the 40 patients in the rotatory group developed paresthesia after surgery.9 Fashioning a bone lid can facilitate treatment by obviating extensive osteotomies and the creation of large bone defects and therefore allowing dental implants to be inserted subsequently in most cases.5 Bone defects can be corrected with regeneration
1490
CONSERVATIVE BONE LID WITH PIEZOSURGERY
FIGURE 7. Case 1. A, Intraoral view of permanent restoration. B, Periapical x-ray after permanent rehabilitation. Sivolella et al. Conservative Bone Lid With Piezosurgery. J Oral Maxillofac Surg 2015.
procedures, such as bone block grafting or guided bone regeneration techniques, but this generally takes time, adds to the costs, and is associated with a higher risk of complications.5-7 Currently available data on jaw cyst enucleation do not support the utility of bone grafts.14 Spontaneous bone regeneration, even in large defects of the body of the mandible, can be
achieved after closing primary bone defects from jaw cyst enucleation provided an adequate mucoperiosteal flap is placed on solid margins. In fact, the physiologic formation of a stable blood clot and its gradual transformation into mature bone tissue are feasible, even in large mandibular defects.14-16 Restoring the bone lid to its original position and embedding it
FIGURE 8. Case 2. Preoperative orthopantomogram. The left mandibular second premolar is completely impacted and distally oriented. Sivolella et al. Conservative Bone Lid With Piezosurgery. J Oral Maxillofac Surg 2015.
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FIGURE 9. Case 2. A, Piezoelectric osteotomy on the buccal plate of the mandible. B, Removal of the bone lid and surgical extraction of tooth 35. C, Extracted left mandibular second premolar. D, The buccal bone lid is put back in place and fixed with microplates. Sivolella et al. Conservative Bone Lid With Piezosurgery. J Oral Maxillofac Surg 2015.
firmly at the end of the surgical procedure help to stabilize the initial coagulum inside osseous defects. The shape of the osteotomy obtained with piezosurgery favors this result.9 In the present cases, it proved difficult to remove the screws at the time of implant surgery. Damage to the heads of 3 screws in case 1 and 1 screw in case 2 prevented the screwdriver from engaging securely. The authors preferred not to remove the residual fragments because they had no influence on the final outcome. The decision to fashion a bone lid can be driven by various factors, such as 1) the dimensions of the lesion to treat; 2) the nearness of delicate anatomic structures; 3) the feasibility of returning the lid to its original position and fixing it efficiently; 4) whether the residual alveolar bone and mucoperiosteal flap can ensure adequate bone lid vascularization; 5) the chances of fashioning a bone lid of sufficient size
and thickness to avoid sequestrum; 6) the condition of the mucoperiosteal flap; and 7) the patient’s characteristics (avoiding patients who might not comply fully with the recommendations concerning the immediate postoperative period). Careful planning of the removal of bone lesions using a conservative approach such as the bone lid technique can enable the bone tissue to heal, thus limiting the formation of large defects. Spontaneous new bone formation can occur even in large mandibular defects secondary to the removal of alveolar bone lesions without the need for bone substitutes. This makes delayed implant-based prosthetic rehabilitation feasible. Acknowledgments The authors acknowledge Dr Sergio Squarzoni for his help in completing the prosthetic rehabilitation of case 2.
1492
CONSERVATIVE BONE LID WITH PIEZOSURGERY
FIGURE 10. Case 2. A, Detail of the immediate postoperative orthopantomogram. B, Detail of the orthopantomogram at time of implant placement, 4 months after tooth extraction. C, Detail of the orthopantomogram after permanent rehabilitation. Sivolella et al. Conservative Bone Lid With Piezosurgery. J Oral Maxillofac Surg 2015.
References 1. Lindorf HH: Bone flap closure following opening of the maxillary antrum (in German). Dtsch Zahnarztl Z 29:587, 1974 2. Bacci C, Sivolella S, Brunello G, et al: Maxillary sinus bone lid with pedicled bone flap for foreign body removal: The piezoelectric device. Br J Oral Maxillofac Surg 52:987, 2014 3. Biglioli F, Chiapasco M: An easy access to retrieve dental implants displaced into the maxillary sinus: The bony window technique. Clin Oral Implants Res 25:1344, 2014 4. Degerliyurt K, Akar V, Denizci S, et al: Bone lid technique with piezosurgery to preserve inferior alveolar nerve. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 108:e1, 2009 5. Khoury F: The bony lid approach in pre-implant and implant surgery: A prospective study. Eur J Oral Implantol 6:375, 2013 6. Esposito M, Grusovin MG, Felice P, et al: Interventions for replacing missing teeth: Horizontal and vertical bone augmentation techniques for dental implant treatment. Cochrane Database Syst Rev 4:CD003607, 2009 7. Chiapasco M, Zaniboni M, Boisco M: Augmentation procedures for the rehabilitation of deficient edentulous ridges with oral implants. Clin Oral Implants Res 17:136, 2006 8. Jung SR, Bashutski JD, Linebaugh ML: Application of modified bony lid technique to remove or replace compromised implants: Case series. Implant Dent 22:206, 2013
9. Pappalardo S, Guarnieri R: Randomized clinical study comparing piezosurgery and conventional rotatory surgery in mandibular cyst enucleation. J Craniomaxillofac Surg 42:e80, 2014 10. Facco E, Zanette G, Favero L, et al: Toward the validation of visual analogue scale for anxiety. Anesth Prog 58:8, 2011 11. Vercellotti T: Technological characteristics and clinical indications of piezoelectric bone surgery. Minerva Stomatol 53:207, 2004 12. Barone A, Santini S, Marconcini S, et al: Osteotomy and membrane elevation during the maxillary sinus augmentation procedure. A comparative study: Piezoelectric device vs. conventional rotative instruments. Clin Oral Implants Res 19: 511, 2008 13. Kocyigit ID, Atil F, Alp YE, et al: Piezosurgery versus conventional surgery in radicular cyst enucleation. J Craniofac Surg 23:1805, 2012 14. Ettl T, Gosau M, Sader R, et al: Jaw cysts—Filling or no filling after enucleation? A review. J Craniomaxillofac Surg 40:485, 2012 15. Ihan Hren N, Miljavec M: Spontaneous bone healing of large bone defects in the mandible. Int J Oral Maxillofac Surg 37: 1111, 2008 16. Chiapasco M, Rossi A, Motta JJ, et al: Spontaneous bone regeneration after enucleation of large mandibular cysts: A radiographic computed analysis of 27 consecutive cases. J Oral Maxillofac Surg 58:942, 2000
Rehabilitation With Implants After Bone Lid Surgery in the Posterior Mandible Stefano Sivolella, DDS, PhD,* Giulia Brunello, DDS,y Mario Berengo, MD, DDS,z Marleen De Biagi, DDS,x and Christian Bacci, DDS, PhDk Bone defects are often secondary to alveolar disease removal. Creating a bone lid with piezosurgery is a valid method to preserve the alveolar bone. A careful and precise osteotomy associated with a firm placement of the bone lid in its original position enables better bone healing, thus allowing for the delayed insertion of dental implants at the operated site with no need for any bone augmentation procedures. The aim of this technical note is to present the application of the bone lid surgery in the posterior mandible before dental implant rehabilitation. Ó 2015 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 73:1485-1492, 2015 Fashioning a bone lid involves cutting a window and removing a portion of bone, which is subsequently returned to its original position at the end of the surgical procedure. This technique enables large bone defects secondary to access osteotomies to be avoided. It can be used in several clinical situations, such as the accidental displacement of foreign bodies into the maxillary sinus1-3 or to gain access to teeth or alveolar bone lesions.4,5 The removal of lesions, such as cysts or tumors, or impacted teeth from alveolar bone is often associated with residual defects that prevent the use of dental implants without performing augmentation procedures.6,7 In such cases, the ideal treatment is as conservative as possible to preserve alveolar bone. Bone lid osteotomies can be performed with a microsaw,5 a long shank drill,8 or piezosurgery.2-4,9 Before the osteotomy is completed, the bone window can be pre-plated with microplates to ensure the bone lid’s stability after it has been put back in place.2 Alternatively, small holes can be drilled into the lid and the surrounding bone to allow for the lid to be fixed with resorbable sutures. For precise, thin, beveled osteotomies, a bone lid can even be fitted stably and accurately in place without any need for further fixation.5 In a recent prospective study, Khoury5 described 200 consecutive patients treated using the bone lid
approach during pre-implant and implant surgical procedures. In 124 patients the bone lid was put back in place without any simultaneous implant positioning or bone graft procedures, and the mean alveolar crest width was reportedly 7.6 0.8 mm immediately after reimplantation of the bone lid. Three months later, the alveolar crest was substantially well preserved in most cases (mean width, 7.1 1.2 mm). In another 76 patients, the bone lid was returned to its original position simultaneously with implant insertion and, in some cases, with bone augmentation procedures (depending on the adequacy of the bone volume and any evidence of infection) and normal healing without any infection was observed. Jung et al8 treated 10 patients using a modified bone lid technique to remove failed implants. In 3 patients, the implants were replaced immediately. Some changes were made to the original bone lid technique, including the use of grafting materials. The aim of the present technical note is to illustrate, through 2 clinical cases, the value of the bone lid technique in the treatment of posterior mandibular pathologic conditions. Implant-supported prosthetic rehabilitation is possible in spontaneously regenerated bone in the edentulous posterior mandible after the first surgical bone lid procedure.
Received
Padova, Via Giustiniani 1, 35129 Padova, Italy; e-mail: giulia-bru@
from
the
Section
of
Dentistry,
Department
of
Neurosciences, University of Padova, Padova, Italy.
libero.it
*Consultant. yResident.
Received February 9 2015 Accepted March 15 2015
zFull Professor.
Ó 2015 American Association of Oral and Maxillofacial Surgeons
xResident.
0278-2391/15/00342-0
kConsultant.
http://dx.doi.org/10.1016/j.joms.2015.03.050
Address correspondence and reprint requests to Dr Brunello: Section of Dentistry, Department of Neurosciences, University of
1485
1486 The patients were fully informed about their condition and consented to the clinical and surgical procedures, which included taking photographs of the lesions and procedures. The procedures described complied with the World Medical Association Declaration of Helsinki on medical research protocols and ethics.
Report of Cases CASE 1
A healthy 64-year-old male patient presented with an extensive radiolucent lesion in the posterior portion of the left mandible that apparently extended from the roots of an endodontic-treated third molar. The patient was clinically asymptomatic and the lesion was an incidental radiographic finding (Fig 1). After preoperative computed tomography (Fig 2), surgery was performed under local anesthesia and sedation.10 A crestal incision was made within the keratinized gingiva in the edentulous mesial area and extended within the sulcus to left mandibular third molar and a distal releasing incision was made. A mucoperiosteal flap was reflected buccally and the third molar was extracted. Adequate access to the lesion was assured by a buccal bone lid fashioned using a piezoelectric device
CONSERVATIVE BONE LID WITH PIEZOSURGERY
(Piezosurgery, Mectron SpA, Carasco, Italy; insert OT7; Fig 3A). After its removal, the bone lid was placed in sterile saline solution. The pathologic tissue was removed from the surgical site, leaving the inferior alveolar nerve intact (Fig 3B). No filling material was used. The buccal bone lid was returned to its original position and stabilized with 1.3-mm fixation microplates (Synthes GmbH, Oberdorf, Switzerland; Fig 3C). The flap was put back in place and sutured. The histopathologic findings were consistent with a radicular cyst, confirming the clinical and radiologic preoperative diagnosis. One year after removing the cyst, healing and spontaneous filling of the residual cavity were confirmed on postoperative orthopantomogram (Fig 4) and computed tomogram (Fig 5). There were no signs of recurrent cyst. The fixation plates were removed (1 year after their insertion) and 3 1-stage implants (XiVE S, DENTSPLY Friadent, Mannheim, Germany) were inserted using a surgical guide at the same time (Fig 6). The patient was referred back to his dentist for prosthetic rehabilitation. He was fitted with a provisional metal-and-acrylic fixed prosthesis 4 months after implant surgery and with a permanent cemented metal-and-ceramic prosthesis after 10 months (Fig 7A, B). The patient was followed with annual
FIGURE 1. Case 1. Preoperative orthopantomogram shows a roundish well-defined radiolucent lesion apically to the left mandibular third molar. Sivolella et al. Conservative Bone Lid With Piezosurgery. J Oral Maxillofac Surg 2015.
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FIGURE 2. Case 1. Preoperative computed tomogram showing multiplanar reconstructions of an area of left mandibular third molar. The buccal bone is preserved but the mandibular canal is not always recognizable. Sivolella et al. Conservative Bone Lid With Piezosurgery. J Oral Maxillofac Surg 2015.
clinical examinations and radiographs of his implants and prosthetics. CASE 2
A healthy 54-year-old female patient presented with a complaint of impaired masticatory function associated with partial edentulism in the posterior left mandible. A preoperative panoramic radiograph (Fig 8) visualized an unerupted ectopic mandibular premolar in the lower left mandible, which prevented any implant placement in the edentulous ridge. The premolar was extracted under local anesthesia and sedation.10 An adequate full-thickness flap was reflected and the ectopic tooth was accessed through a buccal bone lid fashioned using a piezoelectric device (Piezosurgery; insert OT7; Fig 9A). After removing the bone lid and placing it in sterile saline solution, the tooth was dissected and then extracted, leaving the
inferior alveolar nerve intact (Fig 9B, C). No grafting material was used to fill the cavity. The buccal bone lid was returned to its original position with a 1.5mm fixation microplate (Synthes GmbH; Figs 9D, 10A) and the flap was put back in place and loosely sutured. Four months later, the fixation screws and plate were removed and 2 2-stage implants (Osseotite, Biomet 3i, Palm Beach Gardens, FL) were inserted in the posterior left edentulous mandibular ridge during the same procedure (Fig 10B). After another 4 months, the implants were exposed and the patient was referred to her dentist for permanent, cemented metal-and-ceramic prosthetics (Fig 10C).
Discussion A piezoelectric device used to fashion a bone lid2-4 enables a selective, accurate, thin cutting of hard
1488
CONSERVATIVE BONE LID WITH PIEZOSURGERY
FIGURE 3. Case 1. A, After left mandibular third molar was extracted, the mandibular buccal bone lid was fashioned using piezosurgery. B, Removing the bone lid provided access to the cystic lesion. C, The buccal bone lid was put back in place and fixed with microplates. Sivolella et al. Conservative Bone Lid With Piezosurgery. J Oral Maxillofac Surg 2015.
FIGURE 4. Case 1. Orthopantomographic assessment 1 year after cyst removal. Sivolella et al. Conservative Bone Lid With Piezosurgery. J Oral Maxillofac Surg 2015.
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FIGURE 5. Case 1. Computed tomogram 1 year after surgery clearly shows a complete recovery. Fixation screws are in place and well integrated. The mandibular canal is readily detectable in all reconstructions. Sivolella et al. Conservative Bone Lid With Piezosurgery. J Oral Maxillofac Surg 2015.
tissues, decreases the risk of inferior alveolar nerve damage, limits intraoperative bleeding, and provides a better view of the surgical field.4,11 Using piezosurgery helps to obtain precise, beveled-edge osteotomies, and this facilitates the subsequent embedding of the bone windows. Neither of the present patients complained of any postoperative sensory impairment of the inferior alveolar nerve. Similar results were reported by Degerliyurt et al.4 The time it takes to complete the osteotomy using piezosurgery is comparable to the time taken using conventional instruments.2,12 Khoury5 reported tak-
FIGURE 6. Case 1. Detail of the immediate postoperative orthopantomogram at the time of implant placement and plate removal. Sivolella et al. Conservative Bone Lid With Piezosurgery. J Oral Maxillofac Surg 2015.
ing a shorter time to complete similar procedures using a micro-saw. Kocyigit et al13 compared the use of piezosurgery with conventional surgery for radicular cyst enucleation in the jaw. Nineteen patients were treated using piezosurgery and 10 using conventional rotational burs. No surgical or postoperative complications were observed in the piezosurgery group. No soft tissue damage occurred in the other conventionally treated group, but intraoperative hemorrhage severe enough to interfere with the procedure was reported in 3 cases and manipulation difficulties were encountered in 5 cases, resulting in major cystic epithelial perforation. In this latter group, there also were 2 cases of postoperative hemorrhage and 2 of cyst recurrence. They also reported longer operating times for cyst enucleation using piezosurgery.13 A randomized clinical trial also was conducted to compare piezosurgery with conventional rotatory surgery for mandibular cyst enucleation in 80 patients (40 per group).9 Subjective postoperative pain was recorded daily for 7 days using a visual analog scale and was lower in the piezosurgery group. Patients treated with the piezoelectric technique also had less swelling, a shorter recovery time, and no nerve damage, whereas 2 of the 40 patients in the rotatory group developed paresthesia after surgery.9 Fashioning a bone lid can facilitate treatment by obviating extensive osteotomies and the creation of large bone defects and therefore allowing dental implants to be inserted subsequently in most cases.5 Bone defects can be corrected with regeneration
1490
CONSERVATIVE BONE LID WITH PIEZOSURGERY
FIGURE 7. Case 1. A, Intraoral view of permanent restoration. B, Periapical x-ray after permanent rehabilitation. Sivolella et al. Conservative Bone Lid With Piezosurgery. J Oral Maxillofac Surg 2015.
procedures, such as bone block grafting or guided bone regeneration techniques, but this generally takes time, adds to the costs, and is associated with a higher risk of complications.5-7 Currently available data on jaw cyst enucleation do not support the utility of bone grafts.14 Spontaneous bone regeneration, even in large defects of the body of the mandible, can be
achieved after closing primary bone defects from jaw cyst enucleation provided an adequate mucoperiosteal flap is placed on solid margins. In fact, the physiologic formation of a stable blood clot and its gradual transformation into mature bone tissue are feasible, even in large mandibular defects.14-16 Restoring the bone lid to its original position and embedding it
FIGURE 8. Case 2. Preoperative orthopantomogram. The left mandibular second premolar is completely impacted and distally oriented. Sivolella et al. Conservative Bone Lid With Piezosurgery. J Oral Maxillofac Surg 2015.
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FIGURE 9. Case 2. A, Piezoelectric osteotomy on the buccal plate of the mandible. B, Removal of the bone lid and surgical extraction of tooth 35. C, Extracted left mandibular second premolar. D, The buccal bone lid is put back in place and fixed with microplates. Sivolella et al. Conservative Bone Lid With Piezosurgery. J Oral Maxillofac Surg 2015.
firmly at the end of the surgical procedure help to stabilize the initial coagulum inside osseous defects. The shape of the osteotomy obtained with piezosurgery favors this result.9 In the present cases, it proved difficult to remove the screws at the time of implant surgery. Damage to the heads of 3 screws in case 1 and 1 screw in case 2 prevented the screwdriver from engaging securely. The authors preferred not to remove the residual fragments because they had no influence on the final outcome. The decision to fashion a bone lid can be driven by various factors, such as 1) the dimensions of the lesion to treat; 2) the nearness of delicate anatomic structures; 3) the feasibility of returning the lid to its original position and fixing it efficiently; 4) whether the residual alveolar bone and mucoperiosteal flap can ensure adequate bone lid vascularization; 5) the chances of fashioning a bone lid of sufficient size
and thickness to avoid sequestrum; 6) the condition of the mucoperiosteal flap; and 7) the patient’s characteristics (avoiding patients who might not comply fully with the recommendations concerning the immediate postoperative period). Careful planning of the removal of bone lesions using a conservative approach such as the bone lid technique can enable the bone tissue to heal, thus limiting the formation of large defects. Spontaneous new bone formation can occur even in large mandibular defects secondary to the removal of alveolar bone lesions without the need for bone substitutes. This makes delayed implant-based prosthetic rehabilitation feasible. Acknowledgments The authors acknowledge Dr Sergio Squarzoni for his help in completing the prosthetic rehabilitation of case 2.
1492
CONSERVATIVE BONE LID WITH PIEZOSURGERY
FIGURE 10. Case 2. A, Detail of the immediate postoperative orthopantomogram. B, Detail of the orthopantomogram at time of implant placement, 4 months after tooth extraction. C, Detail of the orthopantomogram after permanent rehabilitation. Sivolella et al. Conservative Bone Lid With Piezosurgery. J Oral Maxillofac Surg 2015.
References 1. Lindorf HH: Bone flap closure following opening of the maxillary antrum (in German). Dtsch Zahnarztl Z 29:587, 1974 2. Bacci C, Sivolella S, Brunello G, et al: Maxillary sinus bone lid with pedicled bone flap for foreign body removal: The piezoelectric device. Br J Oral Maxillofac Surg 52:987, 2014 3. Biglioli F, Chiapasco M: An easy access to retrieve dental implants displaced into the maxillary sinus: The bony window technique. Clin Oral Implants Res 25:1344, 2014 4. Degerliyurt K, Akar V, Denizci S, et al: Bone lid technique with piezosurgery to preserve inferior alveolar nerve. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 108:e1, 2009 5. Khoury F: The bony lid approach in pre-implant and implant surgery: A prospective study. Eur J Oral Implantol 6:375, 2013 6. Esposito M, Grusovin MG, Felice P, et al: Interventions for replacing missing teeth: Horizontal and vertical bone augmentation techniques for dental implant treatment. Cochrane Database Syst Rev 4:CD003607, 2009 7. Chiapasco M, Zaniboni M, Boisco M: Augmentation procedures for the rehabilitation of deficient edentulous ridges with oral implants. Clin Oral Implants Res 17:136, 2006 8. Jung SR, Bashutski JD, Linebaugh ML: Application of modified bony lid technique to remove or replace compromised implants: Case series. Implant Dent 22:206, 2013
9. Pappalardo S, Guarnieri R: Randomized clinical study comparing piezosurgery and conventional rotatory surgery in mandibular cyst enucleation. J Craniomaxillofac Surg 42:e80, 2014 10. Facco E, Zanette G, Favero L, et al: Toward the validation of visual analogue scale for anxiety. Anesth Prog 58:8, 2011 11. Vercellotti T: Technological characteristics and clinical indications of piezoelectric bone surgery. Minerva Stomatol 53:207, 2004 12. Barone A, Santini S, Marconcini S, et al: Osteotomy and membrane elevation during the maxillary sinus augmentation procedure. A comparative study: Piezoelectric device vs. conventional rotative instruments. Clin Oral Implants Res 19: 511, 2008 13. Kocyigit ID, Atil F, Alp YE, et al: Piezosurgery versus conventional surgery in radicular cyst enucleation. J Craniofac Surg 23:1805, 2012 14. Ettl T, Gosau M, Sader R, et al: Jaw cysts—Filling or no filling after enucleation? A review. J Craniomaxillofac Surg 40:485, 2012 15. Ihan Hren N, Miljavec M: Spontaneous bone healing of large bone defects in the mandible. Int J Oral Maxillofac Surg 37: 1111, 2008 16. Chiapasco M, Rossi A, Motta JJ, et al: Spontaneous bone regeneration after enucleation of large mandibular cysts: A radiographic computed analysis of 27 consecutive cases. J Oral Maxillofac Surg 58:942, 2000
