TMJ Condylar Osteochondroma: Complete Condylectomy and Joint Replacement Vs. Low Condylectomy and Joint Preservation

Statement of the Problem: Recommended treatment for patients with osteochondromas of the mandibular condyle is to perform complete condylectomy with joint replacement. Low condylectomy with joint preservation has recently been proposed as a treatment option, but is an untested controversial treatment option. Until now, there has been no study comparing the two techniques nor is there any study involving a relatively large sample of patients, given the rarity of osteochondromas of the mandibular condyle. This study compares the outcomes between these two treatments in patients with condylar osteochondromas.

Materials and Methods: We conducted an institution review board approved retrospective analysis of 21 patients (14 females and 7 males) with an average age of 34 years (range 15 to 53 years) and with mandible condylar osteochondromas. For study purposes, they were divided into 2 groups: Group A = 13 patients who had complete condylectomy and joint replacement, and, Group B= 8 patients who underwent low condylectomy and joint preservation. Further, in Group A, TMJ reconstruction was done with either autogenous, costochondral grafts (n=2) or patient-fitted, alloplastic joints (n=11). Inclusion criteria included: 1) post-surgical histopathologically-confirmed TMJ condylar osteochondroma, 2) preoperative progressive facial asymmetry indicating active lesions, 3) preoperative progressive changes in occlusion, and 4) single-stage surgery involving tumor removal, TMJ reconstruction and orthognathic surgical procedures. To optimize occlusion, function and esthetics, maxillary and/or mandibular orthognathic procedures were performed as necessary to re-establish vertical ramus height.

Methods of Data Analysis: Outcomes were measured clinically and radiographically by comparing before surgery (T1) and at the longest follow-up (T2) variables. Clinical evaluations were performed by one examiner.  Subjective variables assessed included levels of TMJ pain, overall headaches on a 10-point visual analog scale (VAS), with 0 being no pain and 10 being the worst pain imaginable. For each patient, other subjective outcome parameters analyzed on a similar 10-point scale included: jaw function (0 = unable to open and 10 = no restriction); diet (0= only liquids and 10 = no restriction); and disability (0 = no disability and 10 = total disability). Objective examinations involved the measurement of maximal inter-incisal opening, and lateral excursions in millimeters. For statistical purposes, the subjective variables assessed on numerical VAS levels were managed as continuous variables, whereas data on objective assessment of maximum inter-incisal opening and lateral excursions was managed as discreet values. For all comparisons, a Student’s t-test was performed and statistical significance for differences was set at a p value < 0.05.

Results of Investigation: Both groups demonstrated significant clinical improvement (p< 0.05), with no tumor recurrence. Group A had longer OR time and donor site complications in those who received autogenous joint reconstruction as compared to alloplastic joint replacement.  Group B, had a shorter OR duration with quicker postoperative recovery. Orthognathic procedures were found to be stable in all cases.

Conclusion: Both complete and low condylectomy are viable options for the surgical management of osteochondromas of the mandibular condyle. Low condylectomy, when indicated, permits effective removal of the tumor and has the advantages of eliminating the need for autogenous or alloplastic joint reconstruction. Further, in patients where complete resection is necessary due to extent of the tumor and TMJ reconstruction required, patient-fitted TMJ replacements provide similar clinical outcomes as compared to autogenous reconstruction, but have the advantages of eliminating donor site morbidity and decreased operating time.

References:

Wolford LM, Mehra P, Franco P: Use of Conservative Condylectomy for Treatment of osteochondroma of the Mandibular Condyle. J Oral Maxillofac Surg 60:262, 2002

Iizuka T, Schroth G, Laeng RH, et al: Osteochondroma of the mandibular condyle. J Oral Maxillofac Surg 54:495, 1996