The Inverted Coronoid-Ramus Graft for Condylar Reconstruction.

The purpose of this article is to describe a creative, versatile technique for condylar reconstruction using autogenous mandibular bone. The technique has been used for reconstruction of small condyle and/or ramus defects (approximately 35 to 40 mm in length) typically associated with condylar hyperplasia, condylar tumors, idiopathic condylar resorption, and failed reconstruction attempts. The technique involves excision of the ipsilateral coronoid process-mandibular ramus, inverting it and rotating the segment 180° along its horizontal axis to replace the excised condyle. The resultant graft simulates the morphology of the posterior aspects of the ramus and condyle and has been shown to resist resorption typical of endochondral bone grafts harvested from the rib or iliac crest. Grafting is carried out via vestibular and preauricular or endaural incisions. Four cases followed over a period of 3 to 40 months (average, 21 months) are presented. No adverse functional results, including ankylosis, removal of hardware or adverse remodeling, have occurred. A period of intermaxillary fixation is used because it is considered beneficial for intra-articular scarring of the subglenoid fossa pad (disc or retrodiscal tissue and fibrocartilage) and initial healing. Physical therapy has not been prescribed. The inverted coronoid graft is a versatile technique when virtual surgical planning is used to assess feasibility, as well as defect and graft dimensions; fabricate custom bone plate and drilling guides; and determine screw osteosynthesis sites. In general terms, a post-reconstruction opening of 35 mm allows for adequate function and guards from contralateral symptomatic hypermobility given disparate right- and left-sided joint mechanics. In the cases described, a mean of 40.5 mm was achieved; however, in 2 of these cases, this was measured with undesirable asymptomatic (preoperative) deviation to the ipsilateral side by greater than 4 mm and by 6 mm. The inverted coronoid graft technique reduces operative time, can be executed with few external scars, and reduces the number of operative fields.

Vector control in transportation osteogenesis.

PURPOSE: To evaluate the ability to control vectors in the technique of transportation osteogenesis using 4 principles. PATIENTS AND METHODS: Sixteen defects measuring approximately 30-180 mm were retrospectively evaluated. Vector control was attempted using a single or combination of the following principles: multiple linear vectors, exaggerated linear distraction ("sausage effect"), braced guided distraction, and reorientation osteotomies. Observations were made regarding the ability to create the desired vectors. Angular deviation from desired vectors was determined and recorded numerically by evaluating either submental vertex or occlusal radiographs, stereolithographic models, or digital radiographs. Radiographic evaluation of symmetry alone was not used to determine the desired vector because a more laterally displaced segment was desirable to maintain favorable facial balance when soft tissue deficiency was pronounced. A subjective evaluation scale was developed to supplement the numerical values. RESULTS: Vector control primarily required the use of 2 or more principles. The most common combination was that of exaggerated linear distraction and reorientation osteotomy. CONCLUSION: The use of multiple linear vectors, exaggerated linear distraction ("sausage effect"), reorientation osteotomies, and braced guided distraction greatly assisted the operator in achieving the goal of symmetrical reconstruction. Transportation osteogenesis may be considered an effective tool in the box to reconstruct patients. In cases in which vector control is achieved, the advantages of diminishing the volume of bone graft required or achieving final bony reconstruction can outweigh the disadvantages of the technique.