Bone graft sandwich osteotomy to correct a malpositioned dental implant

Abstract

As a result of inadequate planning, poor judgment, or losing one’s orientation during surgery, implants may be placed in positions or at angulations that are less than ideal. The purpose of this report is to describe an alternative technique for the correction of a malpositioned osseointegrated implant by means of a maxillary anterior single implant segmental osteotomy associated with a ‘sandwich’ bone graft technique. The technique described provides an alternative option for the surgeon faced with a malpositioned endosseous implant. It allows for a predictable result with preservation of the cervical gingival architecture, creates a more ideal environment for dental restoration, reduces treatment time compared to other techniques, and does so in a cost-effective manner.

As a result of inadequate planning, poor judgment, or losing one’s orientation during surgery, implants may be placed in positions or at angulations that are less than ideal. The rehabilitation of a poorly positioned dental implant can be a challenging clinical situation. This is particularly the case when the area involved is esthetically important, such as the anterior maxillary teeth. The treatment options are basically limited to three alternatives. First, the implant may be left in place ‘sleeping’, not being the support to a prosthetic rehabilitation. Second, it can be surgically removed and replaced. This specific alternative may lead to hard and/or soft tissue defects, which can jeopardize the outcome. Third, it can be moved to a better position. This technique can be performed by peri-implant osteotomy.

Kole was the first to refer to such a small osteotomy, which was used for the repositioning of a one-tooth segment to correct a diastema. Rhesus monkey revascularization and bone healing studies have shown that the intraosseous and intrapulpal circulation associated with the surgical movement of single or multiple dental osseous segments is maintained when the bone cuts are made away from the apices of the teeth and the mobilized segments pedicled to mucoperiosteum.

The purpose of this report is to describe an alternative technique for the correction of a malpositioned osseointegrated implant by means of a maxillary anterior single implant segmental osteotomy associated with a ‘sandwich’ bone graft technique.

Case report

A healthy 42-year-old woman presented for clinical examination of a malpositioned dental implant. An endosseous implant had been placed in the region of the maxillary left central incisor at a private practice, 3 years prior to this evaluation. Following osseointegration, the implant was definitively restored with a prosthesis that included a small portion of cervical gingiva ( Fig. 1 ). Furthermore, the patient had a gummy smile, showing the limit between the prosthesis and gingiva during normal function. She was not satisfied with the esthetics. All the possible treatment options were discussed and a single-implant segmental osteotomy was considered the best treatment option.

Fig. 1
Malpositioned dental implant with unsatisfactory prosthesis.

Clinical examination showed an osseointegrated implant that was positioned excessively apical and labial. Maxillary and mandibular impressions were made preoperatively, including the implant. Plaster model surgery was then performed, and the one-implant segment was repositioned 4 mm lingually and 5 mm coronally from the implant collar. A transoperative provisional single tooth prosthesis was fabricated at the correct position ( Fig. 2 ).

Fig. 2
Model surgery and provisional single tooth prosthesis.

Before any surgical appointment, the patient was informed of the possible complications and benefits, and verbal and written consent was obtained. At the surgical appointment, anesthesia was given in an outpatient setting using a combination of intravenous sedation and 4% articaine with 1:100,000 epinephrine (5.4 ml) local anesthetic. The provisional crown was screwed onto the implant. Access for the osteotomies was created through a full-thickness mucoperiosteal trapezoidal flap, maintaining 3 mm attached gingiva, only on the buccal side. One horizontal osteotomy of the buccal cortex was performed approximately 4 mm apical to the implant using a thin sagittal saw. In a similar fashion, vertical osteotomies were made at the mesial and distal aspects. The osteotomies were then completed using spatula osteotomes, with care taken not to cause trauma to the palatal and cervical mucosa. The implant segment was subsequently mobilized and repositioned with minimal difficulty. The designs of the bony and soft tissue incisions were made to pedicle the mobilized segments to lingual and labio-buccal soft tissue.

Final positioning of the segment was assured with the placement of a bone fragment inside the superior gap, associated with a 1.2-mm bone plate ( Fig. 3 ). The bone graft was removed from the retromandibular area. The wound was copiously irrigated with normal saline and closed using 4–0 vicryl sutures. The provisional crown was left slightly below the occlusal plane. Although some orthodontic brackets were attached to adjacent teeth, no fixed orthodontic wire was used because the bone plate in association with the bone graft provided satisfactory stabilization. The patient was prescribed amoxicillin (875 mg twice a day for 7 days), nimesulide (100 mg twice a day for 5 days), dipirona (500 mg four times a day for 2 days), and chlorhexidine gluconate rinses (twice a day for 14 days).

Jan 24, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Bone graft sandwich osteotomy to correct a malpositioned dental implant
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