Inadequate Implant Angulation Resulting From Oroantral Fistula
http://www.implantoloji.info/articles/12/1/Inadequate-Implant-Angulation-Resulting-From-Oroantral-Fistula/Page1.html
By JDI editor
Published on 02/8/2001
Su-Gwan Kim, DDS, PhD
Assistant Professor, Department of Oral and Maxillofacial Surgery, College of Dentistry, Chosun University, Kwang-Ju, Korea.
Successful implant surgery is largely dependent on good treatment planning and careful surgery. A complete treatment plan must encompass both surgical and prosthetic considerations for the implant restoration. Some compromised implants are restorable, and the result can be acceptable if they can be adjusted into a more ideal position. The goals of the segmental osteotomy are the preservation of a healthy dental unit, the creation of a more ideal environment for dental restoration and occlusal reconstruction, the optimization of cost effectiveness, and the minimization of edentulous space. The purpose of this study is to present the segmental maxillary osteotomy to reposition the alveolar segment with its implant that was in a highly compromised situation.
Assistant Professor, Department of Oral and Maxillofacial Surgery, College of Dentistry, Chosun University, Kwang-Ju, Korea.
Successful implant surgery is largely dependent on good treatment planning and careful surgery. A complete treatment plan must encompass both surgical and prosthetic considerations for the implant restoration. Some compromised implants are restorable, and the result can be acceptable if they can be adjusted into a more ideal position. The goals of the segmental osteotomy are the preservation of a healthy dental unit, the creation of a more ideal environment for dental restoration and occlusal reconstruction, the optimization of cost effectiveness, and the minimization of edentulous space. The purpose of this study is to present the segmental maxillary osteotomy to reposition the alveolar segment with its implant that was in a highly compromised situation.
Case Report
Su-Gwan Kim, DDS, PhD
Assistant Professor, Department of Oral and Maxillofacial Surgery, College of Dentistry, Chosun University, Kwang-Ju, Korea.
A 46-year-old male was referred to the dental clinic in August 1997 with persistent pain of the right maxillary first molar continuing for two weeks and progressive facial swelling caused by advanced periodontitis. He was treated by the extraction of the right maxillary first molar after the resolution of acute symptoms, but an oroantral fistula occurred after the extraction. Closure of the oroantral fistula was performed by using submucosal palatal connective tissue in August 1997, and the wound healed satisfactorily. There were no medical contraindications to dental implant surgery. Panoramic radiographic analysis was done.
Two months later (October 1997), a 3i (Implant Innovations, Palm Beach Gardens, FL) implant (diameter, 5 mm; length, 11.5 mm) was placed in an angulated position in the right maxillary first molar because of anatomical factors (labial alveolar bone resorption and prior oroantral fistula were present). The use of one implant was rejected because of an anatomical factor (poor bone quality) in the right maxillary second molar. In June 1998, phase-two implant surgery took place. In January 1999, the maxillary right second premolar was extracted because of severe mobility.
In February 1999, a 3i (Implant Innovations) implant (diameter, 4 mm; length, 13) was placed in the right maxillary second premolar. In February 1999, a right posterior segmental maxillary osteotomy was performed using the microplate. The patient received a local anesthetic. Using a sterile technique, a vertical incision was made through the mucoperiosteum in the canine region from the crest of the gingiva. Vertical bone cuts were made between the right maxillary second premolar and first molar through the buccal cortical plate to the palatal submucosa. The cuts were approximately parallel to the long axis of the adjacent right maxillary first premolar. A horizontal osteotomy of the buccal cortex was carried superiorly to a point estimated to be 5 mm above the apex of the canine using a thin fissure bur. This was carried posteriorly to join the osteotomy sites. The posterior segment was then freed by using an osteotome and held in place by a microplate (0.6 mm in profile) and microscrews (length, 7 mm; diameter, 1 mm). When the segment was adequately fixed, the flap was sutured with 4-0 Vicryl resorbable material (Ethicon Inc., Somerville, NJ).
Antibiotics and analgesics were administered. Radiographs were taken immediately after surgery to check the osteotomy and verify the position of the microplate and screws.
The patient had no pulpal change in the segmental maxillary teeth after surgery. The patient accepted the procedures well and with minimal morbidity and discomfort. Nine months after osteotomy (November 1999), crowns were placed on the implants. By this time, the centric occlusion was quite satisfactory as compared with presurgical occlusion. After seven months of load, the patient is extremely satisfied with the function of the restoration.
Assistant Professor, Department of Oral and Maxillofacial Surgery, College of Dentistry, Chosun University, Kwang-Ju, Korea.
A 46-year-old male was referred to the dental clinic in August 1997 with persistent pain of the right maxillary first molar continuing for two weeks and progressive facial swelling caused by advanced periodontitis. He was treated by the extraction of the right maxillary first molar after the resolution of acute symptoms, but an oroantral fistula occurred after the extraction. Closure of the oroantral fistula was performed by using submucosal palatal connective tissue in August 1997, and the wound healed satisfactorily. There were no medical contraindications to dental implant surgery. Panoramic radiographic analysis was done.
Two months later (October 1997), a 3i (Implant Innovations, Palm Beach Gardens, FL) implant (diameter, 5 mm; length, 11.5 mm) was placed in an angulated position in the right maxillary first molar because of anatomical factors (labial alveolar bone resorption and prior oroantral fistula were present). The use of one implant was rejected because of an anatomical factor (poor bone quality) in the right maxillary second molar. In June 1998, phase-two implant surgery took place. In January 1999, the maxillary right second premolar was extracted because of severe mobility.
In February 1999, a 3i (Implant Innovations) implant (diameter, 4 mm; length, 13) was placed in the right maxillary second premolar. In February 1999, a right posterior segmental maxillary osteotomy was performed using the microplate. The patient received a local anesthetic. Using a sterile technique, a vertical incision was made through the mucoperiosteum in the canine region from the crest of the gingiva. Vertical bone cuts were made between the right maxillary second premolar and first molar through the buccal cortical plate to the palatal submucosa. The cuts were approximately parallel to the long axis of the adjacent right maxillary first premolar. A horizontal osteotomy of the buccal cortex was carried superiorly to a point estimated to be 5 mm above the apex of the canine using a thin fissure bur. This was carried posteriorly to join the osteotomy sites. The posterior segment was then freed by using an osteotome and held in place by a microplate (0.6 mm in profile) and microscrews (length, 7 mm; diameter, 1 mm). When the segment was adequately fixed, the flap was sutured with 4-0 Vicryl resorbable material (Ethicon Inc., Somerville, NJ).
Antibiotics and analgesics were administered. Radiographs were taken immediately after surgery to check the osteotomy and verify the position of the microplate and screws.
The patient had no pulpal change in the segmental maxillary teeth after surgery. The patient accepted the procedures well and with minimal morbidity and discomfort. Nine months after osteotomy (November 1999), crowns were placed on the implants. By this time, the centric occlusion was quite satisfactory as compared with presurgical occlusion. After seven months of load, the patient is extremely satisfied with the function of the restoration.
Discussion - References.
DISCUSSION.
Patients with highly compromised situations may have either an open bite, inadequate axial inclination of the implant crown, or poor treatment planning. Prosthodontic treatment using endosseous osseointegrating dental implants has proven to be a successful treatment method for complete and partially edentulous patients. The severe or inadequate angulation of an implant is a common problem in implant treatment. The inadequate angulation of the implant is inevitable in many cases. The following common causes of this problem must be considered:
Inadequately placed implants may result in poorly contoured restorations, labial or incisal access hole location, improper prosthetic design, and biomechanical problems. Adequate diagnosis, treatment plan, and meticulous surgery should be performed to prevent these inadequate angulation cases.
Maxillary implants are rarely placed in the direction of the occlusal forces. After tooth loss, the bone is resorbed from the labial aspect first, and labial concavities are often present in this region. Therefore, the implant apex must be placed with a palatal angulation. This anatomical configuration affects the implant angulation and the final treatment plan.
Implants that are angled too far labially can result in placement of screw-access holes through the labial or buccal surfaces of the replacement teeth. Angulated abutments or mesostructures may be necessary for proper placement of screwaccess holes. These implants may even have to be buried to avoid irritation of the movable mucosa with resultant mucosal hyperplasia. Implants that are angled too far lingually can irritate the free mucosa of the mouth floor and cause difficulty with hygiene procedures. In the anterior maxilla, palatally placed implants may interfere with tongue function during speech. In the posterior molar area, a bending moment relative to the implant is created by lateral force, and bending has been demonstrated to produce a poorer distribution of the stresses to the implant and peri-implant bone than an axial load. Bending overload can be prevented by controlling the forces applied to the implants and by obtaining axial implant loading.
Inadequately placed implants have been managed by overcontouring the porcelain and by using angled abutment, custom fabricated abutment, double casting, or overlay casting, screw-retained crown, long crown, secondary bone or soft tissue graft, and additional implants. Maxillary surgical implant repositioning is a reliable, pre dictable method of correcting implants that are malpositioned vertically, anteroposteriorly, transversely, or axially. An implant should be placed to provide for mechanical loading down the long axis of the implant body to the maximum extent possible.4 Bell and Levy reported that an osteotomy was to be performed 5 mm away from the tooth apices to ensure and maintain blood supply with positive pulp tests at six months after surgery. The following are the precautions for surgery: minimal periosteal elevation of the segment, copious irrigation to avoid bone overheating, fixation of the segment, avoidance of intranasal and sinus pressure buildup by having the patient not blow their nose, and keeping the mouth open when sneezing for a period of one month.
From the results of this case, the procedure of the implant segmental osteotomy using the microplate may be recommended for use in association with the immediate correction of an inadequately placed endosseous implant. Continued follow-up is needed to assess the results obtained from using this procedure. Maintenance is an aspect of care that is commonly overlooked but cannot be overstressed.
Fixation of the segment after maxillary or mandibular osteotomies is carried out with microplates and microscrews. A four- to six-month bone healing period has been adequate after osteotomies. However, if any movement of the segment occurs after this period, a longer period (6–8 weeks) of immobilization is indicated and the occlusion should be checked to eliminate any premature contact.
In summary, the best treatment for malpositioned implants is the prevention of their occurrence. To place ideal orientation of the implant, the most important factor is good treatment planning. The successful outcome begins with clearly understood communication between the oral surgeon and the restoration dentist.
REFERENCES.
Patients with highly compromised situations may have either an open bite, inadequate axial inclination of the implant crown, or poor treatment planning. Prosthodontic treatment using endosseous osseointegrating dental implants has proven to be a successful treatment method for complete and partially edentulous patients. The severe or inadequate angulation of an implant is a common problem in implant treatment. The inadequate angulation of the implant is inevitable in many cases. The following common causes of this problem must be considered:
- inadequate surgery not using the surgical template;
- placing the implant to get the maximum intrabony fixation not considering the final shape of the prosthesis;
- inadequate angulation and shape of remaining alveolar bone with missing parts of alveolar process in the case of tooth and alveolar bone trauma;
- anatomical structures such as mandibular nerve and maxillary sinus;
- the shape and position of the jaw; and
- the occurrence of the oroantral fistula.
Inadequately placed implants may result in poorly contoured restorations, labial or incisal access hole location, improper prosthetic design, and biomechanical problems. Adequate diagnosis, treatment plan, and meticulous surgery should be performed to prevent these inadequate angulation cases.
Maxillary implants are rarely placed in the direction of the occlusal forces. After tooth loss, the bone is resorbed from the labial aspect first, and labial concavities are often present in this region. Therefore, the implant apex must be placed with a palatal angulation. This anatomical configuration affects the implant angulation and the final treatment plan.
Implants that are angled too far labially can result in placement of screw-access holes through the labial or buccal surfaces of the replacement teeth. Angulated abutments or mesostructures may be necessary for proper placement of screwaccess holes. These implants may even have to be buried to avoid irritation of the movable mucosa with resultant mucosal hyperplasia. Implants that are angled too far lingually can irritate the free mucosa of the mouth floor and cause difficulty with hygiene procedures. In the anterior maxilla, palatally placed implants may interfere with tongue function during speech. In the posterior molar area, a bending moment relative to the implant is created by lateral force, and bending has been demonstrated to produce a poorer distribution of the stresses to the implant and peri-implant bone than an axial load. Bending overload can be prevented by controlling the forces applied to the implants and by obtaining axial implant loading.
Inadequately placed implants have been managed by overcontouring the porcelain and by using angled abutment, custom fabricated abutment, double casting, or overlay casting, screw-retained crown, long crown, secondary bone or soft tissue graft, and additional implants. Maxillary surgical implant repositioning is a reliable, pre dictable method of correcting implants that are malpositioned vertically, anteroposteriorly, transversely, or axially. An implant should be placed to provide for mechanical loading down the long axis of the implant body to the maximum extent possible.4 Bell and Levy reported that an osteotomy was to be performed 5 mm away from the tooth apices to ensure and maintain blood supply with positive pulp tests at six months after surgery. The following are the precautions for surgery: minimal periosteal elevation of the segment, copious irrigation to avoid bone overheating, fixation of the segment, avoidance of intranasal and sinus pressure buildup by having the patient not blow their nose, and keeping the mouth open when sneezing for a period of one month.
From the results of this case, the procedure of the implant segmental osteotomy using the microplate may be recommended for use in association with the immediate correction of an inadequately placed endosseous implant. Continued follow-up is needed to assess the results obtained from using this procedure. Maintenance is an aspect of care that is commonly overlooked but cannot be overstressed.
Fixation of the segment after maxillary or mandibular osteotomies is carried out with microplates and microscrews. A four- to six-month bone healing period has been adequate after osteotomies. However, if any movement of the segment occurs after this period, a longer period (6–8 weeks) of immobilization is indicated and the occlusion should be checked to eliminate any premature contact.
In summary, the best treatment for malpositioned implants is the prevention of their occurrence. To place ideal orientation of the implant, the most important factor is good treatment planning. The successful outcome begins with clearly understood communication between the oral surgeon and the restoration dentist.
REFERENCES.
- Guerrero DCA, Laplana R, Figueredo N, et al. Surgical implant repositioning: A clinical report. Int J Oral Maxillofac Implants. 1999;14:48–54.
- Palmer R, Palmer P, Floyd P. Basic implant surgery. Br Dent J. 1999;187: 415–421.
- Haganman CR, Aquilino SA. Restorative implications for optimal implant placement. Oral Maxillofac Surg Clinics North Am. 1996;8:387–399.
- Misch CE, Bidez MW. Occlusal considerations for implant-supported prostheses: implant protective occlusion and occlusal materials. In: Misch CE. Contemporary Implant Dentistry. 2nd ed. St Louis: Mosby; 1999:609–626.
- Krogh PHJ, Collins TA. Complications of osseointegrated implants. Oral Maxillofac Surg Clinics North Am. 1994;6: 837–858.
- Balshi TJ, Hernandez RE, Pryszlak MC, et al. A comparative study of one implant versus two replacing a single molar. Int J Oral Maxillofac Implants. 1996; 11:372–378.
- Piattelli A, Scarano A, Paolantonio M. Clinical and histologic features of a nonaxial load on the osseointegration of a posterior mandibular implant: Report of a case. Int J Oral Maxillofac Implants. 1998; 13:273–275.
- Bell WH, Levy BM. Revascularization and bone healing after posterior maxillary osteotomy. J Oral Surg. 1971;29: 313–320.
- Wong K. Immediate implantation of endosseous dental implants in the posterior maxilla and anatomic advantages for this region: A case report. Int J Oral Maxillofac Implants. 1996;11:529–533.