How to Incorporate Oral Endoscopy Into an Equine Dental Examination

1. Introduction

Accurate identification and documentation of pathology is very important for dental treatment planning. The interdental space, canine teeth, incisor teeth, and associated gingival tissues are positioned near the opening of the mouth and do not require sophisticated techniques for detailed examination and documentation. However, challenges exist in achieving adequate visualization of the caudal portion of the oral cavity due to a number of factors including the following:

• Relatively small mouth opening compared to the length of the oral cavity.
• Presence of a large, powerful tongue that obstructs visualization and impedes instrumentation.
• Restricted buccal space with tight adherence of the cheeks and skin to the skull.

Intraoral imaging systems can be utilized by veterinarians to augment dental examination and to provide intra-operative guidance during extraction or dental treatment procedures.^1–7  The magnified image generated by an intraoral imaging system greatly improves visualization and allows detailed examination (Fig. 1). Generally speaking, instrumentation for intraoral imaging is classified as follows⁷:

• Oral endoscopic system: consists of a rigid endoscope, light source, digital video camera, video monitor, and recording device. Rigid endoscopes for equine use typically have a diameter of 5 mm to 15 mm, working length of 50 cm, and an angled viewing lens of 60 to 115°.
• Handheld intraoral camera: adapted from human dentistry, these have a short, self-contained handpiece (approximately 22 cm long) coupled via USB to a computer with a monitor and software for viewing and recording. The device contains a built-in fixed focus camera with an LED light source and an image capture button located on the handle.

The purpose of this manuscript is to describe the author’s approach using oral endoscopy as a component of dental examination and treatment. For a more comprehensive discussion on intraoral imaging systems and oral photography, the reader is referred to the manuscript by Galloway and Easley.⁷
 

2. Materials and Methods

Endoscopic instrumentation (Fig. 2):

• Rigid endoscope (5.5 mm, 60°; working length 49.5 cm)^a
• Protective sheath (7.9 mm, 5.8 mm capacity, working length 45.7 cm)^b
• Video camera^c and video camera control unit^d
• Digital image capture device^e
• Video monitor,^f light source,^g light cable,^h and laparoscopy towerⁱ

Oral examination procedure sequence:

• Discuss the primary complaint and clinical history with the client.
• Enter the patient information into the image capture device to create a folder for photographs and video obtained during the endoscopic examination.
• Perform an appropriate physical examination and external examination of the head.
• Administer sufficient sedation and analgesia to minimize chewing motion, tongue movement, and head movements (e.g., detomidine hydrochloride^j 0.010–0.020 mg/kg IV with butorphanol tartrate^k 0.005–0.010 mg/kg IV).
• Rinse the horse’s mouth.
• Support the horse’s head in a comfortable position for the horse.
• Perform initial oral examination of the incisor teeth, canine teeth, interdental space, associated soft tissues, and gingiva.
• Insert and open the dental speculum, lower the head and rinse any roughage, food, or foamy saliva accumulated on the occlusal surface of the cheek teeth to improve visualization.
• Elevate the head to continue the intraoral examination utilizing a bright light source and traditional methods.
• After initial intraoral examination, move on to the endoscopic exam.

Intraoral endoscopic examination:^2,5,6,7

• Position the instrumentation tower and monitor for comfortable viewing by the examiner (Fig. 3).

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