Chapter 29 - Oraly cavity soft tissue trauma and salivary glands Flashcards
What causes self-inflicted lingual trauma in horses?
Inadvertent desensitization of the tongue due to diffusion of local anesthetic to the lingual nerve during an inferior alveolar nerve block.
How does the soft tissue of the face and oral cavity typically heal?
It heals well by second intention, usually within two weeks.
What are some non-surgical management strategies for minor oral soft tissue injuries?
Flushing the oral cavity with antiseptic solution, warm salt water, or clean water, and using NSAIDs.
What muscles anchor the tongue to the mandible and hyoid apparatus?
The genioglossus, hyoglossus, and styloglossus muscles.
What nerve provides motor innervation to the tongue?
The hypoglossal nerve (XII).
Which sensory nerves supplies the tongue for regular and special sensory innervation?
The lingual nerve branches from the facial nerve (VII), glossopharyngeal nerve (IX), and vagus nerve (X).
Which part of the tongue is most often involved in lacerations?
The free portion of the tongue.
What clinical signs are associated with tongue lacerations?
Oral hemorrhage, ptyalism, inappetence, anorexia, dysphagia, malodorous breath, and tongue protrusion.
What is a partial glossectomy?
The surgical removal of devitalized sections of the tongue.
How can tissue viability be assessed during tongue surgery?
By evaluating tissue color, temperature, bleeding at an incision, and observing fluorescence after intravenous administration of sodium fluorescein.
What technique is used to assist dorsal-ventral apposition during partial glossectomy?
Removing a wedge of intervening musculature and closing the space with multiple rows of interrupted absorbable sutures.
What type of sutures are recommended for multilayer closure in tongue laceration repair?
Absorbable or nonabsorbable size 0 or 1 monofilament sutures for deep layers and simple interrupted sutures for muscle apposition.
When is second-intention healing considered for tongue lacerations?
In chronic, less extensive lacerations or when economic constraints preclude surgical repair.
How can healed tongue lacerations with poor functionality be managed?
By primary closure techniques after sharp débridement of scar tissue.
What dietary adjustments may be needed post-tongue surgery?
Gruels of pelleted feeds, bran mashes, and wetted hay before transitioning to drier feeds.
How soon after lingual surgery do horses usually begin prehending food adequately?
Within hours to a few days.
What complications can arise after partial glossectomy?
Excessive swelling of the tongue and suture dehiscence.
What functional issue may occur after removing a large part of the tongue?
Involuntary dripping of saliva from the mouth.
What is the cosmetic outcome usually like after partial glossectomy?
The cosmetic appearance is usually highly acceptable.
What performance expectations can be met after partial glossectomy?
Return to full riding performance with the use of a bit is practical.
What structures form the blood supply to the tongue?
The lingual artery, which branches from the linguofacial trunk and supplies the tongue via dorsal lingual branches.
What surgical technique can be used for exposure and traction of the tongue during surgery?
Placing towel clamps or a gauze snare caudal to the laceration.
What role do tension-relieving sutures play in tongue laceration repair?
They reduce tension on the wound margins to support healing.
What is a potential long-term complication of tongue amputation?
Slower eating times and an adaptive phase for prehending food.
How are tongue lacerations with devitalized tissue managed surgically?
By débridement of nonviable tissue and multilayer sutured closure.
What is the function of the lingual frenulum?
It attaches the caudal aspect of the apex of the tongue to the oral cavity floor.
What complication may occur during recovery from general anesthesia in horses?
Soft tissue trauma in the oral cavity.
How can necrotic tissue be treated during surgical repair of tongue lacerations?
By vigorous débridement and lavage of the wound.
What are the two types of sutures used to close the muscular body of the tongue?
Vertical mattress sutures for deep closure and simple interrupted sutures for apposing the muscles.
What technique is used if the majority of the free portion of the tongue is amputated?
Gruels and soft feeds are introduced before transitioning to harder foods.
Which part of the tongue contains large vallate papillae?
At the approximate division of the tongue body and root.
What are the key postoperative care measures after tongue surgery?
NSAIDs, antimicrobial therapy, dietary adjustments, and monitoring for complications like swelling or suture dehiscence.
Describe partial glossectomy
Correct dorsal-ventral apposition is assisted by removing a wedge of intervening musculature and closing the created space with multiple rows of interrupted absorbable 2-0 or 0 sutures (walking sutures, see Figure 16-11, E). If considered necessary, full-thickness tension-relieving mattress sutures may be placed caudal to the mucosal edges to provide additional support to the wound margins, with care being taken not to disrupt the blood supply. The mucosal edges are subsequently closed with exposed or buried 2-0 or 0 absorbable sutures
(Figure 29-49) Mucosal-to-mucosal closure of the stump is not imperative, but is encouraged to aid hemostasis, to reduce postoperative discomfort associated with an exposed tongue stump, and to hasten wound healing.
Figure 29-49. Closing the tongue stump after partial glossectomy. After amputation of the severely lacerated tongue (A), a wedge of intervening musculature is removed (B). The created space is closed with multiple interrupted rows of sutures (C and D) before closing the mucosa (D
and E).
Figure 29-50. Tongue laceration repair. After vigorous lavage of the wound (A) and débridement of devitalized tissues (B), the laceration is closed with multiple layers of interrupted sutures (C and D). The large vertical mattress tension-relieving sutures are placed first, deep in the tongue musculature.
Primary closure of severe tongue lacerations is obtained how?
A multilayer closure to eliminate dead space is recommended. To relieve tension on the closure, vertical mattress sutures are preplaced deep in the muscular body of the tongue with absorbable or nonabsorbable size 0 or 1 monofilament suture material. Buried rows of simple interrupted 2-0 to 0 monofilament absorbable sutures are subsequently used to appose the muscles, obliterating dead space. The vertical mattress sutures are tied, and the lingual mucosa is apposed with simple continuous or interrupted vertical mattress sutures (Figure 29-50).
Figure 29-51. Repair of a laceration involving the commissure of the lips. (A and B) After appropriate débridement and lavage of the laceration, the skin and mucous membrane margins of the laceration are undermined 1.0 to 1.5 cm (stippled area in [A]). (B) Cross-sectional view with (a) skin; and (b) mucous membrane. Next, vertical mattress sutures tied over stent material are preplaced through the lip musculature before closing the mucous membrane and skin layers to reduce motion at the suture lines (C and D). Extra vertical mattress sutures can be placed rostral to the repair to further stabilize the site (C).
What types of trauma can cause lip injuries in horses?
Protruding objects like metal buckets, nails, bolts, hooks, and iatrogenic bit damage.
What type of injury may require surgery to preserve lip function and cosmetic appearance?
Mandibular degloving injuries with extensive avulsion of oral soft tissues.
What surgical technique is used for injuries with extensive tissue contusion and devitalization?
Delayed primary closure to optimize the amount of healthy tissue for suturing.
Why is general anesthesia preferred for lip trauma repairs?
It facilitates a meticulous repair.
Important steps of lips closure
Preplacing vertical mattress sutures and undermining the wound margins.
How is motion at the lip suture line reduced during repair?
By sharply undermining the skin and mucosa margins for 1 to 1.5 cm from the wound edges.
What type of sutures is recommended for lip repairs?
Vertical mattress nonabsorbable sutures tied over quills or buttons.
What is the suture pattern used at the mucocutaneous junction?
Vertical mattress pattern.
What additional sutures are recommended for lip commissure injuries?
Vertical mattress tension-relieving sutures rostral to the primary repair.
What surgical technique can be used for extensive lower lip lacerations?
A rotational flap.
How are avulsions of the lower lip supported during repair?
By passing large mattress sutures through the mandible to maintain anatomical alignment.
What type of suture material is used for lip and mandible avulsions?
Wire or nonabsorbable suture material.
How are dead space and motion at the repair site minimized during mandibular lip avulsion repairs?
By threading sutures through drilled holes in the mandible and tying them externally.
When is antimicrobial therapy required in lip trauma cases?
When there is extensive trauma or sutures passed through bone.
How soon can the stent sutures be removed after lip repair?
After 7 to 10 days.
What is the most common complication after lip trauma surgery?
Suture line dehiscence.
How can rubbing of the surgical site be prevented postoperatively in horses?
by using muzzling or cross-tying.
What complication can arise from large, full-thickness cheek lacerations if not treated?
Orocutaneous fistula development.
What clinical signs might suggest the presence of a foreign body in the tongue?
Ptyalism, anorexia, halitosis, and painful swelling of the tongue.
What rare congenital condition affects the tongue’s ability to protrude?
Persistent lingual frenulum (ventral ankyloglossia).
What is the treatment of choice for persistent lingual frenulum in foals?
Frenuloplasty, taking care not to incise the normal lingual frenulum under sedation and LA
What is the most common oral neoplasm in horses?
Squamous cell carcinoma.
What clinical sign may indicate the presence of an oral neoplasm?
Dysphagia, weight loss, and halitosis.
How can mandibular lymphadenopathy be misleading in cases of oral neoplasia?
It may be caused by reactive inflammation rather than metastatic disease.
Which oral tumors tend to recur after excision?
Squamous cell carcinoma and fibrosarcoma.
What type of oral tumor in horses is most successfully managed by surgical excision?
Lingual tumors (except squamous cell carcinoma).
What nonneoplastic condition can mimic the appearance of oral tumors?
Focal gingival hyperplasia (epulis).
What is a common postoperative complication of extensive tongue exploration?
Ptyalism and tongue swelling.
What are the three major paired salivary glands in horses?
Parotid, mandibular, and polystomatic sublingual glands.
Which salivary gland in the horse secretes mainly serous fluid?
The parotid salivary gland.
What type of fluid is secreted by the mandibular and sublingual glands?
A combination of serous and mucous fluids.
Where is the parotid salivary gland located?
Ventral to the ear in the retromandibular fossa.
What important structures are associated with the surfaces of the parotid gland?
External carotid artery
Internal carotid artery
Maxillary vein
Linguofacial vein
Cervical C2 nerve
Facial nerve
Glossopharyngeal nerve
Hypoglossal n
Retrophzryngeal linfnodes
Parotid linfnodes
What is the name of the duct that drains the parotid gland?
The parotid (Stensen) duct.
Where does the parotid duct open in the mouth?
Into the buccal vestibule adjacent to the maxillary third to fourth premolar teeth.
Where does the mandibular salivary gland extend from and to?
From the atlantal fossa to the basihyoid bone.
Which structures does the medial surface of the mandibular gland cover?
The larynx, common carotid artery, vagosympathetic trunk, and guttural pouch.
Where does the mandibular salivary duct open?
Rostrolateral to the lingual frenulum at the sublingual caruncle.
What is the primary risk of trauma to the parotid gland and its duct?
Lacerations or penetrating wounds leading to the flow of saliva from the wound.
How can a disrupted parotid duct be diagnosed?
By catheterizing the duct via the buccal ostium.
What is the typical time frame for spontaneous closure of most salivary fistulas?
1 to 3 weeks.
What suture pattern is used for closing a severed salivary duct?
A simple interrupted pattern.
What chemical is used for the involution of the parotid gland?
10% formalin.
What are sialoliths composed of?
Calcium carbonate and organic matter.
Where are sialoliths most commonly found in horses?
In the parotid duct.
What imaging technique is considered highly sensitive for detecting sialoliths?
Radiography but not all of them. Ultrasonography is high sensitive.
How are smaller parotid duct calculi sometimes removed?
By massaging them through the oral opening of the duct.
What is the primary treatment for sialoliths causing complete obstruction?
Removal of the sialolith via surgery.
What complication is commonly associated with sialoliths in the parotid duct?
Swelling in the intermandibular and retromandibular space.
What are the main clinical signs of septic sialoadenitis?
Painful gland swelling, fever, and draining tracts.
What is the recurrence rate of sialoliths in horses, according to a study?
24%.
Surgical removal of syalolith
Removal can be performed as a standing surgical procedure under local anesthesia or with the animal under general anesthesia.Cannulation of the parotid duct via the parotid papilla can be helpful to locate the exact calculus position, and the catheter can act as a stent for suturing the duct if primary closure is performed.The entire duct and gland should be lavaged with sterile polyionic solution. Closure of the duct is performed with a simple interrupted or continuous pattern of fine absorbable suture material. Using meticulous technique, primary closure of the duct, subcutaneous tissues, and skin will likely reduce the risk of fistula formation.
What condition involves a fluid-filled tube extending along the ventral surface of the mandible?
Functional discontinuity of the parotid salivary duct.
What fluid characteristic suggests a diagnosis of a salivary mucocele?
Brown, mucinous fluid with high calcium and potassium concentrations.
What is the primary treatment for a ranula?
Marsupialization into the oral cavity.
How long does it typically take for salivary secretions to cease after chemical ablation of the parotid gland?
3 weeks.
What condition is referred to as “grass glands”?
Idiopathic parotiditis.
What happens to the parotid glands in idiopathic parotiditis when the horse is removed from pasture?
swelling resolves.
What rare condition involves salivary tissue in abnormal locations?
Heterotopic salivary tissue.
What are the clinical findings associated with sialolith-induced duct obstruction?
Facial nerve paralysis, quidding, and oral ulceration.
Figure 29-55. (A) Photograph of a horse with a sialolith located in the left parotid duct near the rostral edge of the facial crest. (B) Sialolith removed from a parotid salivary duct. ([B] With permission, Schumacher J, Schumacher J. Diseases of the salivary glands and ducts of the horse.
Figure 29-56. Severely dilated parotid salivary duct and gland of a 1-year-old Quarter Horse gelding with congenital atresia of the parotid duct. The duct ended blindly approximately 1.4 cm from the normal site for the buccal ostium. Line arrows mark the course of the duct. (With permission, Fowler ME. Congenital atresia of the parotid duct in a horse.
What is a ranula?
A mucocele of the mandibular or sublingual ducts, seen as a bluish cyst in the mouth.
What is a possible complication after chemical ablation of the parotid gland?
Transient facial nerve paralysis.
What condition occurs due to accumulated saliva in spaces not lined by epithelium?
Salivary mucocele.
What term refers to the surgical approach that creates a new duct opening in the cheek?
Buccotomy.
What substance may act as a nidus for sialolith formation?
Plant material. Sialoliths appear smooth or slightly spiculated, and gray, yellowish, or white.
What procedure involves threading a suture through a lacerated salivary duct for repair?
Cannulation with size 2 nylon suture.
What are the common types of tumors reported in equine salivary glands?
Adenocarcinoma, acinic cell carcinoma, lymphoma, melanoma, mixed cell tumor, and peripheral nerve sheath tumor.
What clinical signs can tumors in the parotid region present?
External swelling, occasional pain on palpation, and signs involving the pharynx and larynx due to regional compression.
Which horse coat color is commonly associated with melanomas in the parotid salivary glands?
Gray horses.
What imaging modality is useful in determining the distribution of melanomas in the equine head?
CT
Which diagnostic methods are used to confirm the diagnosis of parotid region neoplasia?
Endoscopy, radiography, ultrasonography, cytology of fine-needle aspirate, biopsy, and histopathology.
Why is total parotidectomy considered impractical in horses?
Because it is challenging and generally fails to prevent tumor recurrence, especially with benign mixed cell tumors or acinar tumors.
Which type of tumor often metastasizes in equine salivary glands?
Adenocarcinomas.
What therapy can lymphomas respond to in the treatment of equine salivary gland tumors?
Radiation therapy.
What outcome is possible with early, proactive treatment of localized stage 1 to 2 salivary gland-associated melanomas?
It may prevent extensive disease and morbidity, potentially avoiding euthanasia.
How was a well-encapsulated peripheral nerve sheath tumor successfully treated in a horse?
It was surgically excised with no recurrence at 6 months.
