Management of paracondylar process fracture in three horses.

BACKGROUND: Fractures of the paracondylar process of the occipital bone may cause headshaking, neck pain and neurologic deficits. The condition is being recognised more frequently with increasing availability of computed tomography. However, to date only limited information is available as to presentation, treatment, surgical approach and outcome. OBJECTIVES: To describe the clinical signs, imaging findings, treatment, surgical approach and outcome in three horses diagnosed with paracondylar process fracture. STUDY DESIGN: Retrospective case series. METHODS: Clinical records and diagnostic images of affected cases were reviewed. RESULTS: Two cases had ventral nonunion fractures-one of these presented with neck pain, headshaking and behavioural changes, while in the other the fracture was a suspected incidental finding in a case of poor performance. A third case with a more dorsal fracture presented with acute facial nerve paralysis. Diagnosis was by computed tomography in all cases, although imaging of ventral fractures by radiography was found to be feasible. Where clinical signs could be associated confidently with the fracture, conservative management resulted in improvement but not complete resolution. Repeated recurrence of clinical signs after prolonged periods of remission necessitated surgical removal in one case, which was readily accomplished with the aid of ultrasound guidance, and led to rapid resolution of clinical signs without significant post-operative complications. The surgical approach is described. MAIN LIMITATIONS: Limited follow-up was available. CONCLUSIONS: Paracondylar process fracture should be considered as a differential diagnosis for headshaking, neck pain, poor performance and facial paresis, and is a justification for performing computed tomography in such cases. A multi-disciplinary approach is beneficial due to the potential for orthopaedic, neurologic, ophthalmologic and behavioural clinical signs, with additional need for expertise in diagnostic imaging and pain management. Surgical fragment removal should be considered for ventral fractures.

A computed tomographic study of endodontic and apical changes in 81 equine cheek teeth with sagittal fractures.

BACKGROUND: Sagittal fractures of equine cheek teeth are commonly observed during oral examination. There are few reports on the apical and endodontic pathology associated with such fractures seen during computed tomographic (CT) examination. OBJECTIVES: This study aimed to document the prevalence of CT changes indicative of apical disease in equine cheek teeth, which have suffered a sagittal fracture involving the clinical ± reserve crown. STUDY DESIGN: This study is a retrospective case series. METHODS: CT examinations of equine heads with sagittal fractures of cheek teeth present were reviewed: 81 teeth from 49 horses were identified to have a sagittal cheek tooth fracture. The images were evaluated for apical pathology including gas (in the endodontic system and periapically), widened periodontal space, periapical sclerosis, apical clubbing, cementoma/hypercementosis, lamina dura loss, associated sinusitis and sinus mucosal swelling. An apical infection grading system was created to give each tooth a score. Hounsfield units were used to measure the density of the endodontic, apical and periapical regions. The fracture length ratio was recorded. Statistical analysis was performed using a generalised estimating equation to evaluate predictors of apical infection and associations between clinical signs and CT abnormalities. RESULTS: Eighty-seven sagittal fractures (56 buccal, 17 palatal/lingual and 14 midline) from 81 teeth were recorded (74 maxillary and 7 mandibular). Apical infection was diagnosed in 73% (37/51, P = .05) of buccal, 55% (6/11, P = .07) of palatal/lingual, 100% (13/13) of midline, 100% (6/6) of multiple fractures and 96% (23/24, P = .008) of fractures involving infundibula. There was no significant relationship between apical infection and the presence of clinical signs associated with dental pathology (P = .4). There was no significant association between fracture length ratio and apical infection (P = 1.0). Midline sagittal fractures were significantly associated with sinusitis when compared with all other maxillary fractures (odds ratio [OR] 5.92, 95% confidence interval [CI] 1.67-20.83, P = .006). Loss of the lamina dura was not significantly associated with apical infection (P = .5). MAIN LIMITATIONS: There is a maxillary cheek tooth bias in the data set and the subjective grading system. CONCLUSIONS: A large proportion of fractured cheek teeth have evidence of apical infection on CT examination and therefore warrant treatment.

A tangential radiographic projection for investigation of the equine temporomandibular joint.

OBJECTIVE: To (1) describe a tangential radiographic projection of the equine temporomandibular joint (TMJ) and (2) optimize the radiographic angle and determine its use in standing sedated horses. STUDY DESIGN: Descriptive study. ANIMALS: Cadaveric equine skulls (n=11); 8 horses with a history of quidding or headshaking. METHODS: Tangential radiographic projections were taken of a TMJ of a cadaveric skull before and after intra-articular injection of radiographic contrast. Additional tangential radiographic projections were taken after TMJ dissection and placement of a wire along the articular surface of the mandibular condyle. Subsequently, 3 tangential radiographs were taken of both TMJs of 10 skulls at 75 degrees , 70 degrees , and 65 degrees to the dorsal plane (Rt/Le15Cd70D-Le/RtRVO). Each of the 3 images for each TMJ was ranked by 4 observers who were unaware of the projection angle. Interobserver variation was calculated using a Friedman analysis of variance and significance of the most prevalent angle with a 1-sample repeated measures test. Tangential radiographic projections of both TMJs were then taken of 8 standing sedated horses. RESULTS: Tangential radiographic projections allowed the lateral half of the TMJ to be viewed without superimposition of other structures and the anatomic orientation was determined. A 70 degrees projection to the dorsal plane was ranked as significantly better than other views (P<.001). There was no significant interobserver variation and the technique was safely performed in standing sedated horses with excellent image quality obtained. CLINICAL RELEVANCE: Tangential radiography of the TMJ may complement and add to information obtained from clinical examination and ultrasonography before referral for more advanced imaging techniques.

Evaluation of the long-term oral consequences of equine exodontia in 50 horses.

The aims of this study were to objectively evaluate and quantify the process of post-extraction cheek teeth (CT) dental drift in horses, and to report on associated disorders of CT wear and long-term periodontal health. Fifty horses that had CT oral extraction because of apical infection were prospectively re-examined and a full oral examination, including measurements of some dental parameters, was performed. Narrowing of the extraction space was noted in all cases with complete closure occurring in 18% of horses. The rate of dental drift was calculated as 15.7% of extraction space/year (range 4-50%) and was not associated with the age at extraction (P=0.78) or frequency of dental care since extraction (P=0.48). There was a significant negative relationship between the rate of dental drift and the duration of time since extraction (P=0.008). Overgrowths were present on the opposite CT row in 98% of horses, including opposite the extracted CT and on the Triadan 06s and 11s. No significant difference was noted in either the number of diastemata (P=0.9) or periodontal disease score (P=0.8) between the extraction and the contralateral cheek tooth rows.