INTRODUCTION
Mandibular overgrowth and asymmetry due to post-traumatic condylar hyperplasia was first described by Lund in Denmark 1974 in a cephalometric study of mandibular growth following condylar fractures.
Twenty-one patients were presented who developed unilateral mandibular overgrowth secondary to condylar hyperplasia with history of trauma to the condyle (1), with prominent features including enlarged mandibular condyle (2), elongated condylar neck (3), outward bowing and downward growth of the body, and ramus of mandible on the affected side (4), causing fullness of face on that side and a flattening of face on the contralateral side (See Figure 1).
Figure 1. Post-traumatic condylar hyperplasia (right-hand side).
Unilateral condylar hyperplasia must be differentiated from other states of overdeveloped mandible such as hemifacial hypertrophy, which is a unilateral enlargement of all hard and soft tissues of the face, or chondroma and osteochondroma, which produce similar symptoms and signs but they grow rapidly and may cause a greater asymmetric condylar enlargement. Some patients had a clearly documented condylar fracture but on the opposite side from the deformity (5). Other patients had a normal mandible prior to dislocating T.M.J injury (6). Some other patients’ injury occurred over 2 decades prior to presentation and was documented only by history and had a possible subclinical condyle fracture. In all of these patients, condylar hypertrophy seemed to have resulted from a nonfracture injury. All patients are young adults, with the male to female ratio of 2:1.
MATERALS, METHODS, AND DISCUSSION
Five patients were treated for leFort1 (low-level fracture) osteotomies and bilateral sagittal mandibular osteotomies (7), which are comprehensive surgical plans for correcting facial deformity together with the occlusion (See Figure 2).
Figure 2. Patient before and after osteotomies.
An innovation of new clinical concepts has been used in the correction of facial deformity in 11 patients with post-traumatic condylar hyperplasia condition (syndrome) by applying a new modified alloplastic material (subperiosteal acrylic implant) (8). The occlusion is then corrected using conservative methods such as orthodontics, crown and bridge, or partial denture (See Figure 3). The objectives of this implant surgery are as follows.
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Excellent permanent aesthetic result.
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Indicated to patients who are medically contraindicated to osteotomy surgery.
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Causes less trauma to patients.
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Less time-consuming for the surgeon.
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Retains its shape, thickness, and position (no migration).
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No resorption when subjected to pressure.
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Light in weight and not rejected by patients’ tissue.
Figure 3. Patient before and after implant surgery and occlusion correction.
Twenty-one patients with a primary complaint of facial asymmetry due to post-traumatic condylar hyperplasia, who visited the outpatient department of the maxillofacial surgery, were selected. A detailed history of the mode of onset and duration was recorded, and any obvious facial asymmetry or deviation of the chin was examined. Routine hematological examinations were carried out on all patients preoperatively. The patients were operated through extra oral approaches under general anesthesia with nasoendotracheal intubation. A new modified alloplastic acrylic implant was used to restore the symmetry of the face in 11 patients who were medically contraindicated to an extensive osteotomy surgery or who refused such surgery.
An incision was made at the lower border of the mandible (to avoid a visible scar). By dissection, a surgical tunnel was created at the lateral surface of the body of the mandible and the ascending ramus on the normal side (avoid the mental nerve).The surgical tunnel enlarged enough to accommodate the subperiosteal acrylic implant. The implant was then inserted under the periosteum posterior to the second lower premolar (avoiding the mental nerve) through the surgical tunnels created at the lateral surface of the normal side of the mandible and the ascending ramus. The implant was then fixed by a 0.5 mm stainless steel wire to the lower border of the mandible to prevent any possible movement of the acrylic implant (migration) (9) which may change the postoperative aesthetic appearance of the patients. The wound closed in layers, and systemic antibiotics were given for 5 days postoperation as a prophylactic measure against infection. This surgery was found to give a good postoperative permanent facial symmetry result. The facial deformity can be corrected by the same surgical procedure using a problast subperiosteal implant, which is a new material used especially for a surgical implant (10). It is ultraporous (70–90% porous by volume), which ensures rapid stabilization of the implant by tissue during growth and avoids encapsulation; therefore, it needs no immobilization to the bone like other subperiosteal implants. It is easily carved with a scalpel or a high-speed bur to permit fitting with minimal additional shaping during surgery (11,12).
The problast was found to be nonsatisfactory in the correction of facial deformity due to post-traumatic condylar hyperplasia as it is resorbed by pressure during sleep on the problast side. Many other implants such as ceramics (13) and chrome cobalt bone mesh (14 have been used to restore the symmetry of the face, and all such implants have found to give a nonsatisfactory result.
Table 1. Demographic Data on Treatment and Results
| No. of patients | Age | Sex | Side | Diagnosis | Treatment | Result |
|---|---|---|---|---|---|---|
| 5 | 22–30 | M | Rt & Lt | Post-traumatic condylar hyperplasia | Mandibular osteotomies | Good esthetics |
| 6 | 20–28 | M | Rt & Lt | Post-traumatic condylar hyperplasia | Acrylic implant | Good esthetics |
| 5 | 20–28 | F | Rt & Lt | Post-traumatic condylar hyperplasia | Acrylic implant | Good esthetics |
| 1 | 28 | F | Lt | Post-traumatic condylar hyperplasia | Problast implant | Nonsatisfactory |
| 2 | 22–24 | F | Lt & Rt | Post-traumatic condylar hyperplasia | Ceramic implant | Nonsatisfactory |
| 2 | 25–28 | M | Rt & Lt | Post-traumatic condylar hyperplasia | Chrome cobalt bone mesh | Nonsatisfactory |
Ceramics, which are crystalline structures of inorganic nonmetallic mineral salts produced at a high temperature and are used as a bone graft substitute, are found to have difficulties in fixation to the underlining bones with a major position migration postoperation. Chrome cobalt bone mesh (14) used as a mandibular onlay prosthesis was found to give no satisfactory result postoperation because it requires extensive surgery and results in difficulties in adapting to the mesh (See Figure 4).
Figure 4. Chrome cobalt bone in position.
RESULTS AND POSTOPERATIVE FOLLOW-UP
The lefort1 osteotomies and bilateral sagittal mandibular osteotomies, which are comprehensive surgical plans that correct the facial deformity together with the occlusion, are the treatment of choice for mandibular overgrowth and asymmetry due to post-traumatic condylar unilateral hyperplasia. An innovation of new clinical concepts has been used in the correction of the facial deformity in 11 patients due to post-traumatic condylar hyperplasia condition (syndrome) by applying a new modified alloplastic material (subperiosteal acrylic implant) and was found to give a good satisfactory result.
The first 3 months of postoperative follow-up of the patients treated with problast showed 90% success for the problast and only 5% for position migration.
Five years of postoperative clinical follow-up of patients with the problast showed complete resorption of the problast due to pressure during sleep on the problast.
The acrylic is a radiolucent material, and post operative X-ray scanning of the mandible shows nothing of the alloplastic acrylic material. A regular 5 years’ post-operative (clinical) follow-up study of the patients treated by the acrylic implant showed that the acrylic implant retains its shape and thickness and gives a good permanent symmetry of the face.