Dental implants can be displaced into the maxillary sinus. Retrieval by endoscopic or Caldwell-Luc techniques have been previously reported. A modified Caldwell-Luc technique is presented here, where a small round lateral osseous window is created. A plastic surgical aspirator tip is cut and modified to fit tightly into the access window. The sinus is filled with saline, and the patient is placed in a lateral recumbent position in the dental chair with the involved sinus on the underside. The saline acts as a vehicle to bring out the implant. The festooned aspirator is then introduced into the access window, and the errant implant can be successfully brought to the window for retrieval.
The maxillary sinuses (antra of Highmore) are frequently encountered by dental implant surgeons.1,–4 As a result of edentulism, sinus enlargement by pneumatization results in a decrease of available bone for implant placement. The bone volume can be surgically augmented by a lateral or inferior approach surgery.5 However, the extrusion into the sinus of a dental implant by up to 5 mm may be well tolerated by the lining.6 In fact, a recent implant innovation by Nobel Biocare (Yorba Linda, Calif), the Zygoma Implant, is a very long implant that is intentionally placed through the sinus floor, traverses the sinus cavity, and then passes through the sinus roof into the zygoma. There are two transmucosal entries. This implant takes advantage of the remaining atrophic maxillary bone and the zygoma to support the dental fixed prosthetics. It obviously invades the sinus and is expected to function without infections or complications from the sinus. This may raise questions about the need for augmentation surgeries.
Implants have been known to become displaced into the maxillary sinus. This can occur during surgical placement or during the healing phase. The vulnerable time is usually about the second postoperative week when the bone is remodeling and the implant stability may be compromised.
Two methods for retrieving displaced dental implants have been published, the Caldwell-Luc technique and the endoscopic method.7 An enhancement modification of the Caldwell-Luc method is described in this case report.
A 45-year-old woman presented for implant treatment for edentulous site No. 3. The tooth had been extracted approximately 20 years earlier. There had been pnuematization of the sinus and mesial drifting of the second molar leaving a 7-mm site length. The usual pretreatment informed consent and instructions were presented, and the patient agreed to the treatment. Her medical history was unremarkable. Teeth 1, 3, 16, and 30 were missing or had been extracted previously. Teeth 18 and 19 had been successfully restored with a three-unit, three narrow diameter implant supported by a fixed partial denture. Her periodontal condition and oral hygiene were excellent.
On the day of surgery, the patient was prepped in the usual way. Site 3 was infiltrated on the facial and a right greater palatine block was administered with 1.8 mL of articaine (Septocaine, New Castle, Del). By periapical radiograph the site height was determined to be approximately 10 mm, so a 3.7 mm × 10 mm (Implant Direct, Ventura, Calif) endosseous implant was selected (Figure 1). An envelope incision was made at the edentulous crest. The osteotomy was done in the usual fashion with increasing diameter drills to a depth of 8 mm. The apical end of the osteotomy was then slightly infractured with a 3.25 mm cupped-end osteotome (Implant Innovations, Palm Beach Gardens, Fla). The implant was then introduced into the osteotomy and rotated at 12 rpm. As the implant approached the proper position, the handpiece-driven seating attachment rubbed against the adjacent teeth, so it was removed and a different, thinner placement attachment was used to continue. At the moment when the implant became completely seated it suddenly displaced and slipped into the sinus. Unsuccessful aspiration was immediately attempted. A radiograph revealed that the implant was indeed now located on the floor of the maxillary sinus (Figure 2). The osteotomy was then expanded to 5.7 mm for further aspiration, but this too did not allow for the retrieval of the errant implant. Subsequent periapical radiographs confirmed the easy mobility of the implant (Figures 3 and 4). It changed location with every change in head position and normal tidal respiration. The final position of the implant appeared to be in a posterior alcove of the antrum (Figure 5).
A round lateral maxillary osseous window into the sinus was then created with a No. 8 diamond burr (Figure 6). Multiple unsuccessful attempts at retrieval with surgical aspiration were done.
A plastic surgical suction tip was then cut to fit tightly into the lateral osseous window (Figure 7). The sinus was then filled with sterile saline via a 60-mL syringe through the lateral window. The edentulous crest osteotomy was blocked tightly with a sterile, blood-soaked cotton pledget. The patient was positioned reclining on her right side, in the right lateral recumbent position, so that the sinus was located on the underside (Figure 8). This provides help from gravity in the retrieval process. The surgeon (D.F.) was seated lower than the patient with the dental chair elevated to the maximum. With the patient in this position, the aspirating suction tip was snugly introduced into the lateral window and then immediately and slowly withdrawn. The errant implant suddenly appeared, advancing through the window on a river of saline. It was grasped with an Adson forceps (Salvin, Charlotte, NC) and retrieved (Figure 9).
The osteotomies were then covered with a collagen membrane (Biomend, ZImmer Dental, Warsaw, Ind) and primary water tight closure was obtained with 4–0 Vicryl suture (Figure 10). No bone graft material could be used because there was no intact sinus lining to contain the graft.
The patient was given 1000 mg amoxicillin orally. She was prescribed ammoxicillin with clavulenic acid (Augmentin, GlaxoSmithKline, Philadelphia, Pa) 875 mg twice a day for 10 days and chlorhexidine oral rinse. She was also instructed in coughing and sneezing techniques. That is, she was instructed to say “achoo” during sneezing and open her mouth during coughing to avoid any nasal-antral pressure that might disturb the oral-antral closure. She was also instructed to avoid carbonated beverages that could effervesce through the wound margins and into the sinus. She returned for follow-up appointments, and the site healed uneventfully.
The two maxillary sinuses are located bilaterally in the maxilla. In each there is an ostium for drainage, located in 80% of the cases in the superior portion of the medial wall. In most patients, it is more canal-like because of mucosal thickness. It usually leads into the nasal cavity via the ethmoid infundibulum. Sinus drainage primarily is accomplished by action of cilia. This ciliary action is very efficient. One report showed that the ciliary activity successfully cleared the sinus to the superior ostium even after an inferior opening was surgically created for gravity drainage.1 Foreign bodies in the maxillary sinuses, when very small, are removed by ciliary action. These cilia gently move material in the direction of the ostium and are very effective. However, a foreign body as large and heavy as a dental implant would not be evacuated by this natural phenomenon.
A second, smaller ostium may be present, usually in the middle meatus posterior to the main ostium. These secondary, aquired ostea may occur from the breakdown of the mucous membrane.2
The average capacity of the maxillary sinus varies from 9.5 to 20 mL and averages 14.75 mL. The average dimensions are 3.75 cm vertically, 2.5 cm mediolaterally and 2.5 cm antero-posteriorly. The sinus cavity may also extend into the zygoma.1 Thus, a sinus can usually be filled with 10 to 20 mL of lavage saline.
Dental implants dislocated into the sinuses may become infected.8 Dental implant retrieval has been safely accomplished by endoscopically bringing the errant implant through the surgically expanded ostium many days after displacement.9,–11 However, endoscopically guided sinus surgery has been known to be fatal, albeit rarely, and may be complicated by severe bleeding.12
The implant used in this case was slightly tapered, but this shape obviously did not prevent it from slipping into the sinus. If the fixture mount had not been removed because of the impinging adjacent teeth, the fixture mount might have prevented the incident. The bone was not substantial enough to resist the implant advancement at the implant's fully seated position. The bone was deemed to be Misch type 2 or 3.
Although immediate removal may not be imperative, it may be more appropriate to retrieve the implant during the perioperative time. Delaying retrieval could allow the implant to migrate into an adjacent contiguous sinus. One report described a delayed displaced implant removal where the implant had relocated to from the antrum to the sphenoid sinus.13 Another reported displaced implant migrated after 8 years.14 An errant dental implant was also found in the ethmoid sinus, which is usually not contiguous with the maxillary sinus.15
Most dentists do not have ready access to endoscopic instrumentation, nor are they trained in that modality. Referral for removal is an option, however, an immediate retrieval by the implant surgeon would be advantageous.
The technique presented here relies on saline as a vehicle, a tight-fitting aspirator in the created lateral window, blockage of the ridge crest implant osteotomy, and placing the patient in a lateral recumbent position in the dental chair. This allows air passage only from the ostium and thus saline will flow toward the aspirator. However, it also necessitates immediate slow withdrawal of the aspirator to bring the displaced implant to the window for retrieval. Because of the patient's head position, gravity also helps to bring the implant toward the access window.
This technique uses a smaller and more inferiorly placed osseous access window than that of the Caldwell-Luc. It can be formed by a No. 6 or No. 8 round diamond burr or a 5-mm or 6-mm outside diameter trephine. The window should be larger than the diameter of the lost implant but not large enough to damage adjacent tooth roots.
Dental implants displaced into the maxillary sinus may be retrieved by endoscopic or Caldwell-Luc techniques. A modified Caldwell-Luc is presented here, where a small round lateral osseous access window is created, and a plastic surgical aspirator tip is festooned to fit snugly into the access window. The sinus is filled with sterile saline, and the patient is laterally reclined with the involved sinus on the underside. The aspirator is introduced into the window, and the errant implant can successfully be retrieved by aspiration using the saline as a vehicle.
Dennis Flanagan, DDS, is a private practitioner located in Willimantic, Conn. Address correspondence to Dr Flanagan at 1671 West Main Street, Willimantic, CT 06226. (firstname.lastname@example.org)