Temporomandibular Joint Gap Arthroplasty in Cats

Abstract

Temporomandibular joint (TMJ) ankylosis is defined as fibrous or bony fusion of the mandibular head of the condylar process and the mandibular fossa of the squamous part of the temporal bone. Ankylosis of the TMJ may be intraarticular, extraarticular, or both. The objective of this report is to describe the surgical planning, technique, and outcome of gap arthroplasty for extensive TMJ ankylosis in cats. Client-owned cats (n = 7) were examined clinically and surgical planning included the use of cone-beam computed tomography (CBCT) and tridimensional (3D) printed models. In six of the seven cats, temporary tracheostomy intubation was required. Gap arthroplasty included zygomectomy, coronoidectomy, condylectomy, as well as fossectomy (removal of the mandibular fossa of the temporal bone) and was performed using a piezosurgical unit. In all seven cats, gap arthroplasty was performed without surgical complications. In addition, a clinically acceptable mouth opening was achieved in all cases. However, a noticeable mandibular instability was observed. Medium-term follow-up demonstrated acceptable quality of life with one case of recurrence of ankylosis requiring repeated bilateral surgery, and a second case with recurrence of ankylosis not requiring surgical intervention at the time of manuscript preparation. We concluded that TMJ gap arthroplasty in cats is a salvage procedure indicated in cases of severe intraarticular and extraarticular ankylosis. Diagnostic imaging by means of CBCT and 3D printing are essential for precise surgical planning. The use of a piezosurgical unit allows for safe and precise ostectomy. Clinically, despite the resulting mandibular instability, appropriate prehension of food and water was possible.

Comparison of unilateral rostral, middle and caudal segmental mandibulectomies as an alternative treatment for unilateral temporomandibular joint ankylosis in cats: an ex vivo study

“…[28][29][30] Recently, piezoelectric bone surgery technology has been recommended in maxillofacial surgery in veterinary patients due to its ability to selectively cut mineralized tissue in delicate places, significantly reducing the trauma to underlying soft tissue (eg, neurovascular bundle, muscles, etc). 21,31 As previously reported in patients that underwent gap arthroplasty or condylectomy, 9,12,21 all specimens in the present study showed mandibular drifting after performing segmental mandibulectomy. This postoperative complication is considered acceptable in clinical cases; as the patient can eat, drink and groom itself, selective dental extractions may be required to avoid further oral soft tissue trauma.…”

“…2,6,11,12,[19][20][21] The postoperative recurrence is associated with the inability to remove extensive areas of affected tissue owing to its proximity to vital structures such as the base of the skull and the maxillary neurovascular bundle. 2,11,[19][20][21] While the segmental mandibulectomy between the fourth premolar and first molar teeth had previously been proposed as a possible treatment for unilateral TMJA, 22,23 veterinary practitioners have raised questions regarding which area of the mandible should be addressed and how much bony tissue must be removed. To the best of our knowledge, the specific area of the mandible and amount of bony tissue that must be excised during a segmental mandibulectomy in cats affected by unilateral TMJA has not been established.…”

“…Among these complications are excessive or uncontrollable intraoperative bleeding, facial paralysis and TMJA recurrence. 2,6,11,12,19–21 The postoperative recurrence is associated with the inability to remove extensive areas of affected tissue owing to its proximity to vital structures such as the base of the skull and the maxillary neurovascular bundle. 2,11,19–21…”

Management of Septic Arthritis of the Temporomandibular Joint in Dogs

“…A lateral approach to the TMJ was performed as described in an earlier study (20,21). A full-thickness skin incision along the FIGURE 1 | Illustration of the topographic bone and cartilage anatomy of the left temporomandibular joint (TMJ) and its proximity to the tympanic bulla.…”

“…A lateral approach to the TMJ was performed as described in an earlier study ( 20 , 21 ). A full-thickness skin incision along the caudoventral aspect of the zygomatic arch was performed.…”