Sliding reconstruction of the condyle using posterior border of mandibular ramus in patients with temporomandibular joint ankylosis

Abstract

The traditional approach for ankylosis is gap arthroplasty or interpositional arthroplasty followed by reconstruction of the condyle using, for example, costochondral grafts. As these are non-pedicled grafts, there is eventual resorption with subsequent decrease in height of the ramus, facial asymmetry and deviated mouth opening. The authors have applied the method of total and partial sliding vertical osteotomy on the posterior border of the mandibular ramus for reconstruction of the mandible condyle as a pedicled graft for the correction of temporomandibular joint (TMJ) ankylosis. From 2004 to 2008, 18 patients who were diagnosed with TMJ ankylosis underwent operations for resection of the ankylosed condyle. Two methods were performed depending on the level of osteotomy on the posterior part of the mandibular ramus. All patients were followed-up for an average of 36 months (range 24–48 months). All patients showed apparent improved joint function with no cases of re-ankylosis. The results showed that sliding vertical osteotomy on the posterior border of the mandibular ramus seems to be an alternative and promising method for condylar reconstruction in patients with TMJ bony ankylosis.

The term temporomandibular ankylosis refers to bony or fibrous adhesion of the anatomical joint components with ensuing loss of their function, and is primarily caused by trauma, infection or failed surgery. When this occurs during development, it results in an alteration of the normal potential growth and a reduction of the normal functional spurs necessary for the development of the whole maxillofacial complex . Facial asymmetry is the classical feature in unilateral cases. The chin deviates towards the affected side, the vertical height of the affected side is reduced compared with the unaffected side , and the antegonial notch is prominent on the affected side. Secondary effects on the soft tissues surrounding the mandible result in shortening of the pterygo-masseteric muscle sling and the ligaments attaching the mandible to the skull base.

The treatment of bony ankylosis is surgical, but the methods vary, so surgeons have to decide which method to adopt to achieve the best results subjectively and objectively. The traditional approach for ankylosis is to create a gap with or without interposition of soft tissue. The condyle is then reconstructed using costochondral, clavicular or coracoid grafts. As these grafts are non-pedicled grafts, in the long term they may lead to resorption with subsequent decrease in height of the ramus, facial asymmetry and deviated mouth opening.

M artinez -L age et al. performed osteotomy of the posterior border along with the condyle and replaced the posterior border as a free bone graft for treatment of condylar hypertrophy . L oftus et al. reconstructed the condyle by superior repositioning of the pedicled stump of the proximal condylar segment into the condylar fossa as a local osseous pedicled graft based on the lateral pterygoid muscle in a case of osteochondroma using a titanium mesh . Currently, vertical ramus osteotomy (VRO) is being performed along with neocondyle reconstruction after osteochondroma excision, which has shown satisfactory temporomandibular joint (TMJ) function .

The authors have applied VRO with some modifications for reconstruction of the mandible condyle, which they consider corrects the function and morphology of the orofacial structure but is also safe, effective and less invasive. This study investigates the feasibility of total and partial sliding vertical osteotomy on the posterior border of the mandibular ramus for reconstruction of the mandible condyle and reports the clinical effects.

Patients and methods

Between 2004 and 2008, 18 patients (11 male and seven female) diagnosed with TMJ bony ankylosis underwent operations for resection of ankylosed condyle. Eleven patients with prominent antegonial notch underwent method I ( Fig. 1 ) and seven underwent method II ( Fig. 2 ). Data concerning age, sex, aetiology, joint affected, preoperative and postoperative frontal and lateral cephalometric photographs, panoramic radiographs and maximal mouth opening (MMO) were collected and evaluated and are shown in Table 1 . MMO was gauged in all patients using Vernier callipers.

Fig. 1
Method I. (a) The bony block and prominent antegonial notch. (b) The bony block was resected and the glenoid fossa was recreated. (c) Vertical osteotomy was performed on the entire posterior border of the mandibular ramus and then moved up. (d) Fixation of the bone graft with titanium miniplates and resection of prominent antegonial notch.

Fig. 2
Method II. (a) The bony block. (b) The bony block was resected and the glenoid fossa was recreated. (c) Vertical osteotomy was performed on the proximal posterior border of the mandibular ramus till 1.0 cm above the angle of the mandible and the osteotomized segment was moved up. (d) The ipsilateral autogenous coronoid was implanted in the gap and the bony graft was fixed with titanium miniplates.

Table 1
Characteristics of the patients with TMJ ankylosis before and after surgery with two treatment methods.
Method Gender Age (yrs) Joint-involved Aetiology Follow-up (months) Preop MMO (mm) Postop MMO (mm) Difference in mouth-opening deviation (mm) Increase in ramus height (mm)
I Male 12 Right Infection 18 3.5 37 4.8 4.1
Male 26 Bilateral Fall 35 7 42 3 5.6 (right 5.7/left 5.4)
Female 32 Left Fall 32 9.5 34.5 2.4 6.4
Female 24 Right Traffic accident 24 6.5 28.5 3.6 5.2
Male 18 Left Fall 24 8.5 32 1.6 4.7
Female 9 Right Unknown 36 6 38 0.8 2
Male 19 Right Fall 48 7.5 30 4.5 6
Male 12 Right Traffic accident 32 6.5 29.5 4.6 3.6
Male 19 Bilateral Traffic accident 24 3.5 32 3.2 4.5 (right 4.6/left 4.4)
Female 16 Right Fall 25 0 36 3 3.6
Female 29 Left Fall 18 4.5 35 2.6 6.5
II Female 28 Left Fall 28 7 42 4.5 3.6
Male 19 Bilateral Traffic accident 12 9 39 5.1 5.1 (right 4.9/left 5.3)
Male 8 Right Fall 26 1.5 31 3.7 2.2
Female 20 Left Traffic accident 28 0.5 38 1.2 4.2
Male 10 Right Fall 24 1.5 36 3.9 2.8
Male 7 Right Unknown 48 7 33 4.8 2
Male 12 Right Fall 26 2.5 37 2.5 2.4
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Jan 27, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Sliding reconstruction of the condyle using posterior border of mandibular ramus in patients with temporomandibular joint ankylosis
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