Seeing Inside the Horse's Mouth: How Equine Oral Endoscopy Is Changing Dental Diagnosis
Based on Colorado State University Endoscopy Talks by Denis Verwilghen, DVM
This article is a summarized interpretation of the video content featured below; for full context, nuance, and clarification, readers are encouraged to watch the original presentation
Why Oral Endoscopy Matters in Equine Dentistry?
For decades, equine dentistry has often been jokingly described as "waiving a rasp in the dark." While that image may raise a smile, it highlights a real problem: the horse's mouth is a deep, dark cavity, and without proper visualization, true pathology can be missed.
Oral endoscopy, also known as oroscopy, fundamentally changes how we approach equine dentistry. It shifts the focus away from simply rasping teeth and toward what modern veterinary medicine is truly about: diagnosis, preservation, and precision.
Equine dentistry is not about grinding teeth smooth. It is about preserving the horse's dental capital for as long as possible. And to do that, you must be able to see.
The Horse's Mouth: A Diagnostic Blind Spot
Even with a mouth gag and a strong light source, visual inspection alone has limits. Many veterinarians have encountered cases where multiple exams revealed nothing - until oral endoscopy exposed the real issue.
Fractured check teeth, fissures, pulp exposures, and subtle lesions can easily hide from the naked eye. In one example discussed by Dr. Verwilghen, a fractured 109 tooth went undiagnosed despite several prior examinations. The problem was not expertise; it was visibility.
The right tools create the right diagnostic environment.
Oroscope, Endoscope, and flashlights
There are many ways to look into a horse's mouth:
- A phone flashlight (bright, but ineffective)
- A mouth gag with a better light source
- Multiple observers peering inside
- Dental mirrors
Each step improves visualization slightly. But none compares to oral endoscopy.
An oroscope transforms the oral cavity from a black box into a clearly defined anatomical landscape. Pathologies that are ambiguous or invisible, with mirrors suddenly become obvious.
It's not about finding more problems. It's about making more accurate and more confident diagnoses.
What Evidence Shows
In a pilot cadaver study conducted with veterinary students, different diagnostic approaches were compared:
- Visual inspection with light and probe
- Visual inspection plus a mirror
- Oral endoscopy
- Direct anatomical dissection
The results were clear: oral endoscopy significantly improved accuracy. Subtle fissures and questionable lesions became unmistakable when viewed endoscopically.
Quality of diagnosis, not just quantity, was where oral endoscopy made the biggest difference.
Oral Endoscopy in Dental Extractions
Dental extractions follows a simple but unforgiving rule: "The whole tooth, and nothing but the tooth."
Oral endoscopy helps ensure:
- The correct tooth is identified
- The entire tooth is removed
- No fragments are left behind
- Adjacent bone and teeth remain undamaged
This is especially critical for minimally invasive transbuccal extractions, where performing the procedure without endoscopic guidance is strongly discouraged.
Endoscopy also excels in identifying retained fragments, sequestra, and causes of non-healing of tooth sockets (dental alveoli).
Managing Complex Dental Conditions
- Oral endoscopy plays a key role in:
- Diastema management, particularly in caudal cheek teeth.
- Secondary sinusitis investigations, where oral pathology is often overlooked,
- Oronasal and oral-sinus fistulas, using minimally invasive transbuccal approaches.
- Endodontic and reconstructive procedures, where precise visualization oc occlusal surfaces is essential.
Choosing the Right Scope: What Works (and what doesn't)
Flexible vs. Rigid
Flexible endoscopes are not recommended for oral endoscopy on horses.
- Poor image quality
- Inadequate viewing angles
- High risk of damage from chewing
Rigid endoscopes are the standard.
Viewing Angle
While many scopes are available (0°, 30°, 45°, 70°, 90°), the 70° forward viewing rigid scope offers the best balance for equine oral endoscopy. It provides:
- Excellent visualization of occlusal surfaces
- Partial forward vision for spatial awareness
- Superior guidance during diagnostic and interventional procedures
Length and Diameter
- Ideal lenght: ~40 cm
- Recommended diameter: ~10 mm
Smaller scopes increase the risk of damage. Protective sleeves- especially reinforced flushing sleeves- are strongly recommended for scope longevity.
Why Up is Up Matters
Correct camera orientation is critical. When the camera buttons face upward:
- Maxillary teeth appear at the top of the screen
- Mandibular teeth appear at the bottom
This alignment preserves anatomical logic. If the camera is rotated, instrument movements appear reversed on-screen, making procedures confusing and unsafe.
When in doubt, check your camera orientation before assuming you're lost.
Light: The Most Overlooked Factor
The oral cavity is open to the outside, causing significant light loss.
Blood further absorbs illumination.
Key recommendations:
- Use a high-output light source
- Supplement with external mouth-gag lighting
- Consider angled light cables to reduce bulk
- Protect halogen bulbs by turning them off when not needed
Adequate lighting dramatically improves image quality and diagnostic confidence.
Practical Workflow: How to Use Oral Endoscopy Effectively
The following workflow reflects practical advice shared directly by Dr. Denis Verwilghen during the CSU endoscopy talk.
A structured approach works best:
- Captured a wide-field overview image
- Examine each arcade systematically
- Document every cheek toot individually
- Use endoscopy like a "billiard cue" for controlled movements
- If orientations feels wrong, check the camera
Practice builds fluency. Confidence follows clarity.
Wireless Systems and Phone Adapters: Are they worth it?
Wireless and phone-based systems may be useful for basic investigation, but they have limitations:
- Image lag
- Reduced precision for interventional work
- Poor ergonomics in real clinical settings
For diagnostic-only use, they can be acceptable. For extractions or advanced procedures, they quicly become frustrating.
Oral endoscopy represents a paradigm shift. Equine dentistry is not about treating teeth; it is about diagnosing disease. Rasping is a treatment, not a purpose.
The greatest "aha moment" for many clinicians is realizing just how much pathology was previously invisible. Once you start scoping mouths, there is no going back.
Oral endoscopy is a diagnostic necessity. It improves accuracy, enhances patient outcomes, supports minimally invasive techniques, and elevates equine dentistry to the same diagnostic standard expected in every other area of veterinary medicine.
When you can finally see clearly, dentistry stops being guesswork and starts beign medicine.