The use of reconstruction plates for functional restoration

of Mandibular Osseous Defects

CA. Swaify, MBCh, BDS, BDS, PhD,
S. Khateery, BDS, FAAHD, MS
Oral and Maxillofacial Surgery, Riyadh Denta Center, P.O.Box 1584, Riyadh 11441, Saudi Arabia.

In this report, five cases had been treated for mandibular defects (partial). Three patients were treated after tumor resection while two cases were post traumatic. Reconstruction (stainless steel) plates were used either with or without autogenous bone graft. All patients were followed for at least one year. The result showed that this type of plate fulfilled most of the requirements for man­dibular reconstruction. In addition, these plates are easy to remove after healing is completed.

Mandibular bone defects can be a sequelae of trauma, inflammation, or tumor ablation. A defect which disrupts the continuity of the bony mandibu­ lar arch can cause difficulties with eating, speaking, and containment of saliva, quite apart from the cosmetic deformity that is produced. These results may occur primarily or secondary to deviation of the mandibular stumps during cicatricial healing.
It has been proven that immediate pain-free mobilization, made possible by stable internal fixa­ tion is the key to restoring function in a fractured or resected mandible. Therefore, since the early reports on partialmandibular resections,1,2 exten­ sive experimental and clinical researches evolved various materials and techniques for mandibular reconstruction, whether used alone or with bone grafts. These included wire ligature,3 Kirschner wires, threaded and unthreaded rods,4 silicon rub­ ber implants,5 and external fixation devices with transcutaneous pins.6 The precursors of the metal­ lic mesh trays7-9 were followed by the true mesh trays.10,11 Metal plates were also used for securing a bone graft at both ends,12 or for bridging the graft,13 the most recent development is plates bendable in all directions.
The objective of this report is to evaluate the use of reconstruction plates as a method of reconstruc­ tion of the mandibular contour and stabilization of bone grafts.

Patients were selected according to the stated indications for mandibular reconstruction. Five patients with mandibular defects were treated by reconstruction plates for recontouring of the mandible. Three cases had tumors that required resection of a major part of their mandible and two were post traumatic, three had iliac bone grafts whereas the other two were planned to have the bone grafts as secondary procedure. All patients were healthy individuals except for the mandibular defect.
Data for each patient included the age, sex, diag­ nosis, previous treatment, the surgical procedure, me implant and its anchorage, days of hospital stay, and lapse before implant removal are shown in Table 1. Patients were followed up clinically and radiologically for a minimum of six months. The plates used are SYNTHES Maxillofacial stainless steel reconstruction plates.* The plate is designed to be bent in three planes. The holes in the plate are DCP (Dynamic Compression Plate) design and allow compression to be applied in either direction to stabilize fracture in multiple fragments or bone graft. The construction allows plate contouring and bending between screw holes of 15° without distor­ tion ofthe plate hole.
Screws of 2.7 mm diameter were used for fixation and the plates were placed 4 mm away from the lower border ofthe mandible.
Patients were selected according to the stated indications for mandibular reconstruction. Five patients with mandibular defects were treated by reconstruction plates for recontouring of the mandible. Three cases had tumors that required resection of a major part of their mandible and two were post traumatic, three had iliac bone grafts whereas the other two were planned to have the bone grafts as secondary procedure. All patients were healthy individuals except for the mandibular defect.
Data for each patient included the age, sex, diag­ nosis, previous treatment, the surgical procedure, me implant and its anchorage, days of hospital stay, and lapse before implant removal are shown in Table 1. Patients were followed up clinically and radiologically for a minimum of six months. The plates used are SYNTHES Maxillofacial stainless steel reconstruction plates.* The plate is designed to be bent in three planes. The holes in the plate are DCP (Dynamic Compression Plate) design and allow compression to be applied in either direction to stabilize fracture in multiple fragments or bone graft. The construction allows plate contouring and bending between screw holes of 15° without distor­ tion ofthe plate hole.
Screws of 2.7 mm diameter were used for fixation and the plates were placed 4 mm away from the lower border ofthe mandible.

The cosmetic and functional results were satisfac­ tory, bone healing was obvious in two cases after plate removal [Figs. 1,2]. No evidence of infection or sequestration were observed and all wounds healed primarily.
The extra-oral approach was used in cases no. 1, 2 and 4; the intra-oral approach was used with cases 3 and 5. In every case, except with case no. 4, there was free communication between the neck wound and the oral cavity. No case was complicated by infection, this can be attributed to the atraumatic surgical technique, the pre-operative good oral hygiene and the prophylactic use of antibiotics.
Preliminary contouring of the plate was done with the aid of X-rays and a cadaver's mandible [Fig. 1c]. Precontouring reduces the operating time since little manipulation of the plate is required at the time of surgery and before fixation to the bone stumps.
Although four screws were recommended as a minimum to fix the plate to each end,14 only two screws at each stump were used in this report. The stability was maximal and complications following such a routine were not encountered.
Placement of autogenous bone graft is considered the best definitive method of mandibular recon­ struction.15-17 Primary bone grafting was successful in three of the patients, whereas primary grafting was not considered for the other two patients.2,3 In these two patients, the plate was used to maintain the contour of the mandible, both patients had a good chin prominence and were able to use the remaining teeth satisfactorily [Figs. 3,4]. Integrated healing of bone grafts in three patients support the view that functional stable fixation creates condi­ tions optimum for bone graft healing.18 The use of one piece bone block was followed by excellent healing [Figs. 2b,cj. It was stated that the use of such type of bone graft with reconstruction plate increases the chance for good bone healing.14,17 Early mobilization of the mandible was possible in all patients and this was regarded as one of the most obvious advantages of the technique.17,18
As stated by other authors14,18 this technique obviates the possibility of deformity, which was clear with four patients. In the fifth patient, who already had a deformity, the deformity could be cor­ rected by the use of reconstruction plate [Fig. 5]. No complications were encountered in this study. The reported complications included infection, bone resorption and sequestration, implant and screw loosening, plate fracture, implant migration, skin or mucosal ulceration and implant exposure.9,10,18-24

 
Looking at the reported cases and in view of previ­ ous reports, it can be concluded that reconstruction plates fulfill the essential requirements of bone surgery in terms of functional stability, universal applicability, use with or without bone grafts and problem free removal. These implants can provide a significant reduction of morbidity in patients with osseous defects of the mandible