Courtesy Dr. John Lewis
Figure 1: Laceration on ventral suface of a dog's tongue
Published in the April 2014 issue of Veterinary Practice News.
It was the day after Valentine's Day, and the East Coast was in the throes of yet another snowstorm.
An 8-year-old male great Dane presented to our hospital through the emergency service for sudden onset of bleeding from either the mouth or nose at home. The dog had a prior history of immune mediated thrombocytopenia, so it was a surprise when a complete blood count showed a normal platelet count.
The patient was not very cooperative for a conscious oral examination, and no source of bleeding was visible because bleeding had subsided prior to the patient's arrival. The pet owners declined an anesthetized oral exam, but two hours later a second and more severe episode of bleeding brought the owners and the pet back to the hospital.
The dog's face and front legs were drenched in blood, and packed cell volume and total protein were found to be 24/6.0. During the active bleed, it became obvious that the bleeding was arising from the oral cavity.
The patient was sedated and a thorough oral examination was performed. A class 3 malocclusion (a.k.a. mandibular mesioclusion) was noted and the mandibular incisors were worn due to tooth attrition and/or abrasion. Clots were removed from throughout the oral cavity and pharynx, and the only laceration seen was on the ventral surface of the tongue (Figure 1). A 4 cm linear laceration was noted, which lined up with the sharp, worn cusps of the mandibular incisor teeth.
Upon probing of the laceration with gentle pressure, an arterial bleed was reactivated (Figure 2), and the branch of the lingual artery that was causing the bleeding was identified and ligated.
The laceration was closed with 5-0 polydioxanone, and the mandibular incisors that caused the linear laceration were extracted (Figure 3).
Extraction of the incisors was chosen over simple odontoplasy due to the already severe attrition/abrasion of the teeth and to ensure the bleeding problem would be permanently resolved.
This case is a great example of the importance of a thorough oral examination. The tongue laceration itself was subtle when not actively bleeding, and if the malocclusion and chisel-like mandibular incisors had not been identified as the source of the laceration, the tongue would have continued to get traumatized and bleed.
Courtesy Dr. John Lewis
Figure 2: Gentle probing of the circumscribed red area resulted in profuse arterial bleeding.
Let's review the important aspects of the oral examination.
The head and neck examination begins with extraoral observation of the head, face, eyes, ears and neck using visual observation, palpation and smell.
Always wear gloves when performing an oral examination to avoid being a fomite. Magnification loupes with a light source are very helpful to allow light to be shined on the area of interest.
Using gloved hands, palpate each side of the face, head and neck for symmetrical comparison. Assess the temporal and masseter muscles for the presence of atrophy, enlargement or pain. Palpate the ventral, lateral and medial surface of the left and right mandibles for the presence of swelling that could be evidence of neoplasia, infection or fracture.
The intraoral examination consists of evaluation of the soft tissues of the oral cavity, the dental structures and the periodontium (the supporting structures of the teeth).
Some of this information can be obtained in the conscious patient, but assessment of the periodontium via probing requires anesthesia.
Begin by observing the skin and mucosa of the upper and lower lips. Lip fold dermatitis may occur caudal to the mandibular canine tooth, which can cause oral malodor unrelated to periodontal disease. "Vestibular or labial mucosa? refers to the mucosa that begins at the mucocutaneous junction and lines the cheeks and lips.
"Alveolar mucosa" refers to the mucosa that lies against the bone of the upper or lower jaw, which meets with the gingiva at the mucogingival junction.
Courtesy Dr. John Lewis
Figure 3: Photograph of one of the madibular incisor teeth that had been worn to a chisel point, resulting in trauma to the ventral tongue.
The normal appearance of the mucosa may be pink or pigmented, and the mucosa should exhibit no lesions, ulcerations or swellings. Mucosa that lies adjacent to plaque-covered teeth may have painful mucosal ulcerations, often referred to as contact stomatitis or mucositis.
Buccal mucosa frequently becomes pressed between the teeth during chewing, creating a condition known as "cheek chewing lesions." Similarly, mucosa beneath the tongue may also show signs of chewing lesions referred to as "tongue chewing lesions."
Bumps in the Mouth
Two raised bumps are found on the alveolar mucosa dorsal to the maxillary fourth premolar and first molar teeth. Salivary secretions from the parotid and zygomatic salivary glands travel through ducts leading to these duct openings.
Two similar raised bumps can be found beneath the tongue just caudal to the mandibular symphysis, which are the caruncles of the mandibular and sublingual glands. Care should be taken to avoid trauma to these structures when possible to avoid development of sialoceles.
The roof of the mouth is composed of the hard and soft palate. The hard palate is covered by palatal mucosa arranged in prominent ridges called "rugae." These rugae range from eight to 10 in number.
In brachycephalic dogs, the rugae are closely positioned, and hair and debris can accumulate in these rugal folds. On the midline of the hard palate, just caudal to the incisor teeth, the incisive papilla is a round, slightly raised structure.
Lateral to the incisive papilla, a small bilateral communication with the incisive duct and vomeronasal organ exist. The vomeronasal organ is a sensory organ involved in detection of pheromones and other volatile compounds. Palpation of the area lateral and caudal to the incisive papilla may normally feel as if there is air trapped beneath the mucosa as a result of the communication between the mouth and these nasal structures.
The soft palate consists of mucosa and muscle that separate the oropharynx and nasopharynx. Two prominent bony structures can be palpated just lateral to the midline of the soft palate; these are the hamular processes of the pterygoid bones.
If one or both hamular processes are difficult to palpate, this may be due to the presence of a nasopharyngeal mass. These processes are best palpated in the anesthetized patient due to their location.
The pharynx may be evaluated in cooperative conscious patients for evidence of inflammation or neoplasia. When the patient's mouth is open, bilateral folds of pharyngeal mucosa (palatoglossal folds) will be evident lateral to the tongue. This area and the mucosa lateral to these folds may be inflamed in cats with caudal stomatitis.
Palpate the tongue. The firm, tubular structure palpable on the midline of the rostral tongue is called the "lyssa," which helps to provide structure and coordinated movement of the rostral tongue.
Lift the tongue to observe the mucosa of the floor of the mouth and the base of the tongue. In the conscious patient, the examiner's thumb may be used extraorally to push the tongue dorsally for better visualization of the ventral surface of the tongue.
The dorsal surface of the tongue is covered by thousands of papillae, some of which contain taste buds. The large, distinctive papillae located at the caudal third of the tongue are the vallate papillae, which are spaced in a curved line separating the body from the root of the tongue.
Depress the tongue to visualize the tonsils, noting any enlargement or change in color or texture. The color of a normal tonsil is typically more hyperemic than the color of the adjacent mucosa. Normal tonsils may be either out of their crypts or may be fully contained within the tonsillar crypt and difficult to visualize.
Components of the anesthetized oral exam, including assessment of the teeth and periodontium, will be discussed further in next month's column.
In the meantime, drop me an email if you've ever seen a case of severe oral bleeding from a tongue laceration caused by worn or fractured mandibular incisor teeth. This case in the great Dane was the third I've seen; the other two were boxers, who also had class 3 malocclusions.
Who knew a malocclusion could be such a threat to life?
Enjoyed this article? Learn more here:
The Anesthetized Intraoral Examination
Treating and Preventing Dental Disease in Geriatric Pets
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