Avian Skull Orthopedics

Computed Tomography and a Dental Intraoral Scanner to Generate Three-Dimensional Models of the Beaks of Three Bird Species

This study aimed to assess the beaks of Neotropical birds using two scanning techniques-CT and a dental intraoral scanner-along with macroscopic analysis. Six specimens per family were selected, including parakeets, red-legged seriemas, and black vultures. The upper beaks were measured in the CT sagittal view for length along the longitudinal axis and height on the transverse axis. The same measurements were performed on the 3D images. Additionally, beak width in the middle of the naris area, as well as the length and height of the nares, were measured on the 3D images. The closed polygon tool outlined the beak, generating volume in cm2. The 3D images obtained with the dental scanner were measured, similarly to those from 3D-CT scans for the beaks' length, height, and width. Macroscopic measurements of the beaks were also conducted. Some differences in beak measurements between imaging methods were verified. In conclusion, both techniques are effective, but CT provides more detailed information. The combination of both methods would be ideal for developing and applying beak prostheses.

Diagnostic Approach Using Computerized Tomography and Successful Surgical Resolution of a Palatine Luxation and Entrapment in a Blue and Yellow Macaw (Ara ararauna)

A seven-month-old male blue and yellow macaw (Ara ararauna) was presented with an inability to move the maxillary beak after flying into a clothesline. Unsuccessful attempts to reduce the beak were performed, first by the owner at home and later within the same day by the referring veterinarian under general anesthesia. The patient was referred for assessment and treatment 5 days later. A palatine luxation and entrapment with a possible fissure of palatine bone was suspected based on history, a physical examination, and radiographic imaging. Another unsuccessful attempt to manually reduce the beak was performed under general anesthesia. A computed tomography (CT) scan was scheduled to evaluate the skull further. Rostrodorsal displacement and entrapment of the palatine bone on the rostral edge of the interorbital septum in the mesethmoid region were identified. In addition, the CT images provided useful information for the veterinary team to rule out other skeletal abnormalities, rendering a significantly more detailed evaluation of the skull bones before surgical intervention. Surgery was performed after the previously published pin insertion method over the dorsal aspect of the palatine bone. Pressure in the ventral direction was then applied on the pin while simultaneously further hyperextending the maxillary beak to unhook the palatine bone from the interorbital septum. The present case report describes an in vivo diagnosis of palatine luxation and entrapment in a blue and yellow macaw by means of a CT scan and successful surgical resolution.

Successful conservative management of multiple skull fracture and quadrate-mandibular medial luxation in a blue-and-yellow macaw (Ara ararauna)

BACKGROUND

We present a case of beak trauma not previously been reported in a blue-and-yellow macaw (Ara ararauna) and its successful conservative treatment. Several cases of fractures affecting the mandibular, maxillary and maxillofacial bones and pterygo-palatine dislocations, which have been studied using traditional radiology and CT; however, quadrato-mandibular luxation has never been described, individually or associated with other trauma.

CASE PRESENTATION

A 4-year-old blue-and-yellow macaw (Ara ararauna) was referred for a recent head trauma. The parrot exhibited right lower beak deviation, difficulty in grasping food and difficulty closing the beak. The parrot was referred for multiple traumatic fractures involving the pterygoid bone, jugal bone and right mandibular arch. The X-ray projections showed an incomplete fracture of the right pterygoid bone, two fracture sites on the right jugal arch, and slight mediorostral displacement of the right quadrate bones. Computed tomography (CT) confirmed the X-ray findings, and indicated additional trauma. The right quadrate bone luxation was manually reduced, and conservative treatment was elected. Analgesia and nonsteroidal anti-inflammatory drugs were provided. Moreover, a soft food-based diet was recommended for 3 weeks to facilitate recovery and reduce facial bone movements and tension. The parrot started eating dry food approximately 1 month after the trauma; full return of apparently normal beak function was achieved by 2 months.

CONCLUSIONS

The CT examination allowed us to obtain a more detailed and complete view of the fractures and traumas and to evaluate the complex articular system of the Psittaciformes beak. For these reasons, CT is recommended for birds with a history of head trauma to select the best treatment for the specific case.

Mandibular Prognathism Correction in a Juvenile Umbrella Cockatoo (Cacatua alba) With the Use of an Orthosis

A 9-week-old male umbrella cockatoo (Cacatua alba) presented with mandibular prognathism. The rostral rhinothecal tomial length appeared subjectively shorter than the rostral gnathothecal length, which was subjectively rostrally elongated. After an initial orthosis failed, a second orthosis was designed that employed the use of an orthopedic wire anchor in the rostral end of the rhinotheca, leaving the premaxillary bone undisturbed. Prior to placement of the anchor, skull radiographs were taken to measure the distance from the rostral tip of the rhinotheca to the rostral end of the premaxillary bone. This was done to mitigate iatrogenic trauma and prevent disruption of bone and underlying tissues when the orthopedic wire was deployed to anchor the rhinothecal tip. A hole was created in the rostral rhinotheca with a 20-gauge hypodermic needle rostral to the premaxillary bone. Orthopedic wire was placed through the hole and wrapped over the dorsal rhinotheca as an anchor. A second piece of orthopedic wire was formed into an elongated oval shape as a frame for the rhinothecal extension. Flexible, moldable plastic mesh was wrapped over the rhinotheca and orthopedic wire extension. Waterproof epoxy putty was placed over the rhinotheca and orthotic wires. The epoxy putty was replaced as needed until the rhinotheca had regrown into correct alignment. Twenty-five days post-placement, correct alignment was achieved, and the orthosis removed. The beak remained in correct alignment, and the bird developed normal use of the beak to engage in activities such as feeding, preening, and podomandibulation. Whereas methods for correcting mandibular prognathism have been described utilizing a variety of techniques and materials, there is a paucity of peer-reviewed literature on this procedure. This report describes the management and correction of this condition in a young bird as well as the involved anatomy, kinesiology, and details of this corrective procedure.

Transsinus Pinning to Correct Lateral Deviation of the Upper Beak in Juvenile Macaws

Lateral deviation of the upper beak ("scissor beak" or "wry beak") is a common malocclusion in many species of birds but appears to be a common presentation in macaws (Ara species). This article describes transsinus pinning, a procedure in which a pin is passed through the frontal sinuses, turned parallel to the upper beak, and attached to the tip of the beak with an orthodontic rubber band to provide constant tension on the beak as it grows. The tension of the rubber band is maintained until the beak is considered straight. The results of 16 cases in which this beak-straightening procedure was used are presented. The age of the chicks that had their beaks straightened ranged from 7 to 28 weeks, and they were placed into 2 groups: those younger than 12 weeks (12 chicks; 75%) and those older (4 chicks; 25%). Complete resolution was achieved in 87.5% (14 of 16) of the avian patients that were treated with this procedure. The 2 remaining cases (12.5%) failed to fully respond. The 12 younger birds (75%; age, 7-12 weeks; median, 10 weeks; range, 5 weeks) responded to treatment within 2 weeks (12-85 days; median, 14 days; range, 73 days); the remaining 4 older chicks (25%; age, 14-28 weeks; median, 17.5 weeks; range, 14 weeks) required a longer period (13-90 days; median, 25.5 days; range, 77 days) for the beak to straighten. Transsinus pinning is a simple, effective, and rapid technique for correcting this malocclusion in macaw chicks younger than 16 weeks old. With this approach, in most cases, excellent results can be expected in only 2-4 weeks.