From practitioner to practitioner - ZZI 04/2013

Bone block grafting at a distance from the alveolar ridge for the threedimensional reconstruction in cases of severe lateral and vertical bone atrophy

M. Korsch1, W. Walther1, A. Bartols1

Aim: This case report explains the implantological procedure for the treatment of severe lateral and vertical bone atrophy of an interdental edentulous ridge segment in the maxilla. The indication of using a special bone block grafting technique for the threedimensional reconstruction of the alveolar ridge is described.

Summary: In the case presented here, the first upper left molar had to be extracted in 2010 due to an abscess in connection with a vertical root fracture. In 2011 the alveolar ridge was reconstructed by bone block grafts harvested from the retromolar region. The bone block grafts were fixed orally and facially at a distance from the alveolar ridge by means of osteosynthesis screws. The space created between the 2 block grafts was filled up with particulate autogenous bone and bone substitute material. Three and a half months after augmentation, 2 Astra Osseo Speed implants were inserted.

Keywords: bone block grafting; implants; lateral and vertical atrophy

Citation:

Korsch M, Walther W, Bartols A: Bone block grafting at a distance from the alveolar ridge for the threedimensional reconstruction in cases of severe lateral and vertical bone atrophy. Z Zahnärztl Implantol 2013;29:321?329

DOI 10.3238/ZZI.2013.0321?0329

Introduction

In a large number of implantological interventions, augmentation procedures are inevitable. Depending on the indication and extent of the bone loss, different augmentation techniques are used. For the reconstruction of jaws with vertical bone loss the following procedures are available: Besides onlay grafts [2, 6, 19] and interpositional grafts [11, 12] of autogenous bone and bone substitute material, vertical distraction osteogenesis [18] is another valid option. Techniques often applied in connection with onlay grafts are augmentation by means of a titanium mesh [16, 19], bone blocks as onlay grafts [2, 17] and block grafts at a distance from the alveolar ridge as described by Khoury [14]. Onlay grafts may be made from purely autogenous bone as bone block [2], as particulate bone or mixed (bone block and particulate bone) [6], or bone substitute materials with and without the addition of autogenous bone particles as granulate [16] or as block grafts [2, 11] can be used for augmentation. The amount of autogenous bone needed for augmentation depends on the extent of the bone loss and the bone substitute material being used for gaining volume. The objective of the case presented here was the threedimensional reconstruction of the alveolar ridge after lateral and vertical bone atrophy. A bony implant bed for single tooth replacement was to be created by a bone block graft at a distance from the alveolar ridge.

Case history

On December 1, 2010, the then 51-year-old patient presented at the oral surgery department of the Dental Academy for Continuing Professional Development in Karlsruhe for the first time. He wanted a fixed restoration in the left maxilla and refused to have the adjacent teeth ground. The first upper left molar had previously been extracted as a consequence of a vertical root fracture (Fig. 1). When the tooth was extracted, the dental colleagues already found an extended vertical and lateral bony defect. Due to the vertical root fracture and the subsequent abscess formation, both the vestibular and palatal bone plates were completely resorbed. After the lesion had healed, a massive vertical and lateral bony defect was left in the region of the interdental edentulous ridge segment (Fig. 2). The first and second upper left premolars had been missing since childhood. When the patient was young, the first upper left molar was moved mesially by orthodontic means to close a space between 24 and 25. In an implantological counseling and information session, the therapeutic options, alternatives and sequence of treatment phases were discussed with the patient. He was informed in detail about the conventional prosthetic treatment by means of a bridge.

Findings on December 1, 2010

Intraoral (stomatological) findings

Intraorally a severe loss of vertical and lateral dimension of the edentulous jaw segment at 24/25 was diagnosed. The mucous membranes were adequately moistened and without any pathological findings.

Radiological findings

The edentulous jaw segment at the site of 24/25 had a 7–9 mm deficit of vertical dimension (Fig. 2).

Diagnosis

The findings mentioned above led to the following diagnosis:

  • mild generalized chronic periodontitis
  • alveolar ridge atrophy class 3 (according to Seibert) at the
    site of 24/25

Therapy

Surgical phase:

Augmentation at 24/25

The first surgical intervention was performed on February 16, 2011 under local anesthesia. At 24/25 the implant site was exposed by making a horizontal incision in the vestibulum and elevating a tension-free split-thickness flap. The bony defect at 24/25 was measured with a periodontal probe (Fig. 3) in order to determine the size/amount of augmentation material required.

Then the retromolar region 39 was exposed by an alveolar ridge incision to harvest bone. With a straight and a contra-angle handpiece and diamond-coated cutoff wheels (Miniflex, Komet, Lemgo, Germany) a 20 mm long bone block was taken from the retromolar region. In addition, a pilot drill was used for spot drilling to obtain bone chips which were collected in a bone trap (Titan Knochenfilter KFT3, Firma Schlumbohm, Brokenstedt, Germany). The retromolar region 39 was then sutured with non-resorbable suture material (Supramid 5/0, Resorba, Nuremberg, Germany).

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