Surgical correction of temporomandibular joint ankylosis in two cats

Temporomandibular Joint Gape Angles in Normal and Painful Domestic Felines

The purpose of this study was to determine and compare the gape angles (temporomandibular joint range of motion with mouth opening) of conscious and anesthetized domestic felines and to compare gape angles with and without evidence of oral pain. This prospective study evaluated the gape angle of 58 domestic felines. The cats were grouped into painful (n = 33) and nonpainful cohorts (n = 25) and gape angles were compared during conscious and anesthetized conditions. Gape angles were determined based on measurements of the maximal interincisal distance and lengths of the mandible and maxilla followed by calculation of the law of cosines. The mean feline gape angle (standard deviation) was determined to be 45.3° (8.6°) and 50.8° (6.2°) for conscious and anesthetized felines respectively. There was no significant difference between painful and non-painful feline gape angles during conscious (P = .613) or anesthetized (P = .605) evaluations. There was a significant difference between anesthetized and conscious gape angles (P < .001) for both painful and non-painful cohorts. This study determined the standardized, normal feline temporomandibular joint (TMJ) gape angle in both conscious and anesthetized states. This study suggests that the feline gape angle is not a useful indicator of oral pain. By determining the feline gape angle, which was previously unknown, further evaluation of its utility as a non-invasive clinical parameter for evaluation of restrictive TMJ motions as well as its use for serial evaluations may be pursued.

Post-traumatic ankylosis of the temporomandibular joint in the dog – a case report

Temporomandibular ankylosis, even though considered to be of a relatively rare emergence, can be encountered in day-to-day clinical practice. Most cases follow a typical, if not identical anamnesis pattern. The background of mechanical difficulties manifestation is associated with some trauma. The animals usually suffer a severe blow to the head, leading to a gradual development of the defect, which unfortunately most owners are not aware of, or claim not to be. This case report describes a typical incidence of post traumatic ankylosis of the temporomandibular joint (TMJ). The patient suffered a blow to the head at the age of 4 months, the clinical aftermath of which was a gradual difficulty in opening the mouth. A CT examination revealed the extent of damage in the region of the zygomatic arch, affecting also the corresponding TMJ. For this particular case, a surgical intervention was the only course of treatment, meaning the resection of arcus zygomaticus and the TMJ. The procedure was scheduled to be performed 14 days post the CT examination. Due to the fact that the changes were located only on the lateral surface of the TMJ, the plan was to resect and remove the affected area only, with the medial part of the TMJ left intact and in position. The joint capsule was then sutured. This approach proved to be very beneficial and effective in the outcome of the surgery and in aiding in the overall comfort of the patient.

Temporomandibular joint injuries and ankylosis in the cat

Objective: To evaluate cause, location, treatment, and the clinical outcome of traumatic temporomandibular joint (TMJ) lesions and TMJ ankylosis in cats.

Methods: Cats with TMJ injuries were included in this study. Lesions were classified as luxations, fractures of the condylar process, and intra-articular temporal bone fractures. Signalment, cause and type of injuries, treatment methods, clinical outcome, complications and joint ankylosis were assessed and evaluated statistically.

Results: Temporomandibular joint lesions were observed in 82 of 161 cats with maxillofacial injuries. One hundred forty-nine TMJ lesions were determined in 112 joints. Falling was the most common cause and fractures of the condylar process were the most common types of injuries. Isolated TMJ injuries and caudal TMJ luxations were mainly caused by falling. Condylectomy was used in ankylosis, chronic luxation, reluxation and in two cases with multiple TMJ lesions. Ankylosis was observed in 10.97% of cases and was generally observed in fracture combinations of condylar process and mandibular fossa (Χ2 = 8.52; p <0.05). No significant relationship between age and development of ankylosis (Χ2 = 3.995; p >0.05) was found.

Conclusion: In contrast to previous studies, traumatic TMJ lesions were observed in a considerable amount of cats with maxillofacial injuries, and fractures of the condylar process were the most common type. Lesions caused by falling were mostly simple, whereas vehicular trauma caused more complicated lesions. Ankylosis did not appear as a rare condition. Any cat with TMJ injury is susceptible to the development of ankylosis.

Ankylosis and pseudoankylosis of the temporomandibular joint in 10 dogs (1993-2015)

OBJECTIVE

To describe the clinical features and results of treatment of true ankylosis and pseudoankylosis of the temporomandibular joint in dogs.

METHODS

This study was a retrospective case series. Ten client-owned dogs that were presented for inability to open the mouth or a severely decreased range of motion of the temporomandibular joint were included. Information on the surgical procedures performed and the perioperative complications were documented. Three-dimensional printing of the skull was performed in four dogs.

RESULTS

Two dogs were diagnosed with temporomandibular joint ankylosis and seven dogs with pseudoankylosis. One dog had evidence of combined temporomandibular joint ankylosis and pseudoankylosis. Of the seven dogs with pseudoankylosis, six had an osseous fusion involving the zygomatic arch and mandible. Surgical treatment was performed in nine dogs and a revision surgery was needed in one dog. Follow-up ranged from five months to eight years (mean: 48.6 months). Eight out of nine dogs that were treated surgically regained the ability to open their mouth, but six dogs never regained a fully normal temporomandibular joint range of motion.

CLINICAL SIGNIFICANCE

Temporomandibular joint ankylosis and pseudoankylosis are uncommon in the dog. Surgical treatment for temporomandibular joint ankylosis or pseudoankylosis in dogs is a successful option and carries a prognosis dependent on patient-specific abnormalities. Computed tomography complemented with three-dimensional printing is valuable for understanding the extent of abnormalities and for preoperative planning.

False ankylosis of the temporomandibular joint in a cat. Correction by partial zygomatic arch resection

OBJECTIVE

To describe the use of two-dimensional computer-assisted tomography (CT) with three-dimensional (3D) reconstruction in the diagnosis and planning of surgical treatment of a case of false ankylosis of the temporomandibular joint.

CASE REPORT

A young European Shorthaired cat was presented with the complaint of inability to eat and open its jaws. A CT scan with 3D reconstruction allowed visualization of the lesion which was causing extra-articular ankylosis of the temporomandibular joint. Surgery was performed to resect an osseous lesion of the zygomatic arch, thus freeing the temporomandibular joint. Postoperative physical therapy was initiated immediately following surgery, and then carried out by the owner with a one year follow-up. Clinical examination of the cat was performed during regular office visits (at 1 month and 3 months following surgery), which allowed objective assessment of postoperative recuperation. At the end of a year, the owners reported that the cat had maintained sufficient jaw opening without any signs consistent with chronic pain.

CONCLUSION

Computed tomography scan with 3D reconstruction allowed planning of the surgical correction of extra-articular ankylosis of the temporomandibular joint, and in this case condylectomy was avoided, since temporomandibular joint range-of-motion was maintained.

Superficial temporal myofascial flap application in temporomandibular joint arthroplasty in a cat

Case summary

A 2-year-old, intact female domestic longhair cat was referred for surgical treatment after diagnosis of closed jaw locking secondarily to right temporomandibular joint ankylosis and left pseudoankylosis. The animal underwent successful surgical management with bilateral excision arthroplasty followed by interposition of a temporal superficial myofascial flap. Immediately after surgery, the full range of lower jaw movement was achieved and normal occlusion was maintained. Ankylosis did not recur in the 1 year postoperative follow-up period.

Relevance and novel information

A temporal myofascial flap could be considered as interposition material after temporomandibular joint arthroplasty to avoid postoperative re-ankylosis and mandibular drift. The main advantages of this flap are its autogenous origin, and the ability to maintain separation between the two bones, preserve mobility and disrupt new bone formation.

A Retrospective Study of Temporalis Muscle and Fascia Flap in Treatment of TMJ Ankylosis

BACKGROUND

This study sought to determine the efficacy of interpositional arthroplasty with temporalis muscle and fascia flap in the treatment of unilateral temporomandibular joint (TMJ) ankylosis in adults.

METHODS

This retrospective study of nine cases evaluated the postoperative results of interpositional arthroplasty on temporalis muscle and fascia flap in adults. The operative protocol for unilateral TMJ ankylosis entailed (1) resection of ankylotic mass, (2) intraoral ipsilateral coronoidectomy, (3) contralateral coronoidectomy when necessary, (4) interpositional tissue transfer to the TMJ with temporalis muscle, fascia flap, and (5) early mobilization, aggressive physiotherapy.

RESULTS

The study evaluated nine patients with follow-up checks from 13 to 31 months (mean 18.3 months). Patients had a preoperative maximal interincisal opening of 9-19 mm (mean 11.7 mm). During the last follow-up observation after surgery, the patients had a maximal interincisal opening of 35-40 mm (mean 38.3 mm).The results of this protocol were encouraging, the functional results of interpositional arthroplasty on temporalis muscle and fascia flap were also satisfactory.

CONCLUSION

The findings of this study support the use of temporalis muscle and fascia flap in adult patients with unilateral TMJ ankylosis. Early postoperative initial exercise, physiotherapy and strict follow-up play an important role in preventing postoperative recurrences.

Locked Jaw Syndrome in Dogs and Cats: 37 Cases (1998–2005)

A consecutive series of cases of dogs and cats with locked jaw syndrome (inability to open or close the mouth) are reported in this study. Dogs were significantly overrepresented (84.0 %) and adult dogs were more frequently affected (81.0 %). Temporomandibular joint ankylosis due to fracture was the most common cause (54.0 %) of locked jaw syndrome. Additional potential causes of locked jaw syndrome are masticatory muscle myositis, neoplasia, trigeminal nerve paralysis and central neurological lesions, temporomandibular joint luxation and dysplasia, osteoarthritis, retrobulbar abscess, tetanus, and severe ear disease. Treatment of locked jaw is directed towards the primary cause. It is important to treat the tonic spasm in order to minimize periarticular fibrosis. Surgical intervention is recommended for temporomandibular joint ankylosis. Masticatory muscle myositis treatment is initiated by gradually opening the mouth, with medical treatment based on immunosuppressive therapy. Fracture and masticatory muscle myositis are associated with a relatively good prognosis in regard to short-term outcome as compared to animals with central neurologic lesions or osteosarcoma which have a poor prognosis.

Temporomandibular joint ankylosis and salivary mucocele in a cat: case report

An approximately 1.5-year-old, not neutered mixed breed cat was referred for evaluation of inability to open its mouth, and soft tissue swelling around the intermandibular region. Both signs were present since the cat was adopted, 1 year before presentation. The cause of the signs was not determined prior to referral. Based on the physical and radiographic examinations, left temporomandibular joint ankylosis and salivary mucocele were diagnosed. The lateral aspect of the condyloid process of the left mandible was removed and the salivary mucocele was treated by right mandibular and sublingual gland resection and drainage of the mucocele. After surgery, the cat showed good functional use of the mandible without discomfort.

Imaging of the canine and feline temporomandibular joint: a review

The radiographic anatomy of the temporomandibular joint in the dog and cat is described in dorsoventral and oblique projections. The positioning for different oblique views in conventional radiography and technical details of computed tomography are reviewed. Typical radiographic features of craniomandibular osteopathy, dysplasia, luxation, subluxation, fractures, ankylosis, degenerative joint disease, infection, and neoplasia involving the temporomandibular joint are discussed.

Treatment of temporomandibular joint ankylosis with temporalis muscle and fascia flap

This study sought to determine the efficacy of interpositional arthroplasty with temporalis muscle and fascia flap in the treatment of unilateral temporomandibular joint (TMJ) ankylosis in adults. This retrospective study of seven cases evaluated the postoperative results of interpositional arthroplasty on temporalis muscle and fascia flap in adults. The operative protocol for unilateral TMJ ankylosis entailed, (1) resection of ankylotic mass, (2) intraoral ipsilateral coronoidectomy, (3) contralateral coronoidectomy when necessary, (4) interpositional tissue transfer to the TMJ with temporalis muscle and fascia flap, (5) maxillomandibular fixation (MMF), and (6) early mobilization and aggressive physiotherapy. The results of this protocol were encouraging, while the functional results of interpositional arthroplasty on temporalis muscle and fascia flap were satisfactory. The findings of this study support the use of temporalis muscle and fascia flap in adult patients with unilateral TMJ ankylosis. Early postoperative initial exercise, physiotherapy, and strict follow-up play an important role in preventing postoperative adhesions.

Feline inductive odontogenic tumour in a Burmese cat

A 7-month-old, male, Burmese cat was presented with an oral mass that had rapidly regrown following excisional biopsy 3 weeks earlier. The tumour was identified by histological examination as a feline inductive odontogenic tumour. A unilateral segmental mandibulectomy was performed. Although dental malocclusion resulted from mandibular drift to the operated side, the cat displayed minimal dysphagia post-operatively and there was no evidence of tumour regrowth 8 months after surgery. Feline inductive odontogenic tumour is a rare dental tumour described exclusively in cats under 3-years-of-age. Although histopathologically benign, feline inductive odontogenic tumour grows by expansion and can infiltrate underlying bone to cause considerable local destruction. This article is intended to increase awareness of this unusual tumour which, with complete surgical excision, carries a good prognosis. It also emphasises the importance of obtaining a histological diagnosis from oral mass lesions to direct appropriate therapy and to provide an accurate prognosis.