Purpose: Inverted T-shaped silicone implants have been used for reconstruction of ankylosed temporomandibular joints for 10 years. As the implant is custom made during the operation, dimensional adjustments according to individual need are routine. Material and method: A new modification to increase the stability of the inverted T-shaped silicone implant is presented. The modification consists of a middle process on the long arm of the T-shaped silicone implant, the first of which was inserted into, the medullary cavity of the mandibular ramus. This modification further stabilizes the implant position and helps prevent its displacement. The modification was used on difficult cases such as bilateral ankylosis, osteotomies below the condylar notch or incompliant patients. This modification was used in six patients. Results: No dislocation, nor extrusion of the implant or re-ankylosis of TMJ was observed. (C) 2004 European Association for Cranio-Maxillofacial Surgery.