Successful treatment of a chronic oroantral fistula infected with extensively drug resistant bacteria using long-term oesophageal tube feeding and several non-conventional treatments in a horse.

BACKGROUND: Chronic oroantral fistulae (OAF) with secondary sinusitis can occur following repulsion of cheek teeth in horses. CASE REPORT: An 8-year-old Andalusian cross gelding presented with an iatrogenic clinical crown fracture of tooth 209, which underwent repulsion of its apical portion (day 0). The horse was treated with intramuscular penicillin and intravenous gentamicin (5 days), followed by oral trimethoprim-sulphonamide (10 days) and then oral doxycycline (14 days). The acute iatrogenic OAF created during the initial repulsion persisted; a chronic OAF was identified on day 24. On day 48, septic sinusitis with multidrug-resistant (MDR) Escherichia coli was confirmed. Although susceptible to enrofloxacin in vitro, 30 days of therapy was unsuccessful. Subsequent serial cultures grew multiple MDR and extensively drug-resistant (XDR) gram-negative microorganisms. Whole-genome sequencing (WGS) revealed multiple sequence types of E. coli, with a range of resistance and virulence genes. The orientation of the OAF, regional osteomyelitis and septic sinusitis were confirmed with computed tomography on day 70. On day 74, enteral nutrition was provided through a cervical oesophagostomy tube for 3 months for prevention of oral feed contamination. The OAF was treated with various alternative therapeutics, including apple cider vinegar, propolis and amikacin impregnated products, until resolution on day 116. CONCLUSION: These non-conventional therapeutics, antimicrobials and long-term oesophagostomy contributed to the successful treatment of a complicated OAF. In the future, WGS may be useful to inform antimicrobial selection when MDR or XDR organisms are identified.

Oronasal and Oroantral Fistulas Secondary to Periodontal Disease: A Retrospective Study Comparing the Prevalence Within Dachshunds and a Control Group.

The prevalence of oronasal and oroantral fistulas (ONF/OAF) was retrospectively identified in a population of dachshund patients (dachshund group) and was compared to a population of small breed dogs of significantly similar age and weight (control group). When compared with the control group, the dachshund group was significantly more likely to have an ONF/OAF (P < .0001). The odds ratio indicates that dachshunds were 3.3 times more likely to have an ONF/OAF than individuals within the control group. This study statistically confirms previous reports and clinical observations that dachshunds are predisposed to ONF/OAFs. When ONF/OAFs are present, the maxillary canines are the most commonly affected dentition in both study groups.

Computed tomographic description of the highly variable imaging features of equine oromaxillary sinus and oronasal fistulae.

Oronasal and oromaxillary sinus fistulae are well-documented complications following removal or loss of a maxillary cheek tooth. Diagnosis is currently based on a combination of oral examination, videoendoscopy, radiography, and computed tomography (CT). The objective of this retrospective, case series study was to describe the CT characteristics of confirmed oronasal and oromaxillary sinus fistulae in a group of horses. Inclusion criteria were a head CT acquired at the authors' hospital during the period of 2012-2017, a CT diagnosis of oronasal or oromaxillary sinus fistulae, and a confirmed diagnosis based on a method other than CT. Signalment, clinical findings, oral examination findings, presence of a confirmed fistula, and method for confirmation of the diagnosis were recorded. A veterinary radiologist reviewed CT studies for all included horses and recorded characteristics of the fistulae. Seventeen horses were sampled. Fourteen oromaxillary sinus fistulae and three oronasal fistulae were identified. All fistulae appeared as variably sized focal defects in the alveolar bone. Defects frequently contained a linear tract of heterogeneous material interspersed with gas bubbles, considered consistent with food. Computed tomographic attenuation of the material (Hounsfield units, HU) varied widely within and between cases. In 16 of 17 cases, there was evidence of concurrent dental disease in addition to the fistulae. Although the gold standard diagnostic test remains identification of feed material within the sinus or nasal passages, findings from the current study support the use of CT as an adjunctive diagnostic test for assessing the extent of involvement and presurgical planning.

Successful Treatment of a Persistent Oroantral Fistula via Transbuccal and Transnasal Endoscopic Debridement in a Horse.

We report an unusual case of a young Quarter Horse with a large dental fracture fragment displaced into the maxillary sinus, leaving an oroantral communication that caused food impaction and metaplastic calcification in the sinus and facial deformation with cutaneous fistulation. Oral extraction of a remaining tooth fragment from its alveolus was succeeded by a maxillary sinusotomy for removal of the abnormal sinus contents. Since the oroantral fistula did not heal spontaneously following the placement of a silicone dental prosthesis, minimally invasive transbuccal and transnasal endoscopic approaches were used to encourage closure of the oroantral fistula by alveolar granulation. The clinical, diagnostic, and therapeutic features of this case may be helpful to clinicians when dealing with similar cases.

Radiographic appearance of maxillary sinus feed impaction in a horse.

A 15-year-old Belgian gelding presented in respiratory distress, with bilateral mucopurulent nasal discharge, and right-sided epistaxis. The horse had a 5-year history of dental disease and had been recently losing weight. Radiographs indicated tooth root abscessation of the right maxillary third molar tooth and probable maxillary sinus feed impaction. These findings were confirmed at surgery and necropsy. The stippled, granular radiographic appearance described here is highly characteristic of sinus feed impaction.

Complications associated with cheek tooth extraction in the horse.

Common indications for cheek tooth extraction in the horse include dental fracture, periodontal disease, severe decay/ caries, mandibular fracture with alveolar/tooth involvement, and periapical abscess. Complications secondary to extraction of cheek teeth are prevalent. Typical complications may include retained root tip(s), collateral damage of neighboring teeth and alveolar bone, mandibular fracture non-union or delayed union, cemental ankylosis, dilacerated root(s), oroantral/oronasal fistula, palatal deviation of cheek teeth, bone sequestration, sinus involvement, alveolar plug failure, and palatine artery laceration. This paper presents a series of cases that had complications following cheek tooth extraction. Anticipation of problematic extractions, recognition of complications, and appropriate treatment will aid the clinician in managing the inevitable cheek tooth extraction complication.

Oronasal fistula repair using auricular cartilage.

Seven oronasal fistula lesions secondary to extraction of maxillary canine teeth were treated in 5 dogs using a cartilage graft harvested from the ipsilateral auricular pinna. All dogs had undergone previous, unsuccessful surgeries in attempt to repair the defects. The technique is described in a step-by-step fashion for easy reproduction. The authors found the technique to be straightforward, relatively quick, and successful in all 7 lesions.

Rapid prototype modeling and customized titanium plate fabrication for correction of a persistent hard palate defect in a dog.

CASE DESCRIPTION: An 8-month-old crossbred dog was evaluated because of an oronasal fistula following 2 previous attempts to surgically correct a secondary palate defect. CLINICAL FINDINGS: Three months after initial evaluation and successful closure of the soft palate section of the secondary palate defect via 2 surgeries, an oronasal fistula was present. The oronasal fistula was predominantly right sided, involving the rostral third of the hard palate and, at the widest aspect, spanning the transverse palate at the level of the maxillary canine teeth. TREATMENT AND OUTCOME: Following CT of the rostral aspect of the skull, rapid prototyping technology was used to create a stereolithographic model of the skull, allowing fabrication of a customized titanium plate for intranasal stenting. The titanium plate was inserted via a rostral nasal approach and secured rostrally with 1.5-mm screws and caudally with 2.4-mm screws from the nasal bridge. An oronasal fistula formed laterally at the edge of the plate, but bonding of a dental glass ionomer product resulted in successful resolution of the fistula. CLINICAL RELEVANCE: Results suggested that rapid prototyping and creation of customized implants may provide an option for the management of large or nonreconstructible oronasal defects in dogs.

Free auricular cartilage autograft for repair of an oronasal fistula in a dog.

An eight-year-old female/spayed Pomeranian dog was presented for surgical treatment of an acquired right oronasal fistula. The maxillary right canine tooth had been extracted non-surgically 7-weeks prior to presentation. Clinical signs were consistent with an oronasal fistula during this time period. Oral examination showed an oronasal fistula in the area of the extracted tooth. The referring veterinarian performed simple debridement and suturing with subsequent recurrence of the oronasal fistula. This case report describes the successful surgical treatment of an acquired oronasal fistula with a free auricular cartilage autograft and reviews techniques described for oronasal fistula repair, including free auricular cartilage autografts.

Treatment of oromaxillary fistulae in nine standing horses (2002-2006).

REASONS FOR PERFORMING STUDY: There is minimal published information on equine oromaxillary fistulae that are unrelated to cheek teeth (CT) repulsion or on the conservative treatment of these atypical fistulae. OBJECTIVES: To report equine oromaxillary fistulae unrelated to CT extraction and describe their management in standing horses. METHODS: Case details of oromaxillary fistulae of atypical aetiology occurring at 2 referral centres between 2002-2006, including their treatment and response to treatment were examined. RESULTS: Nine cases of oromaxillary fistula were recorded, mainly in aged horses (median 22 years). Fistulae were associated with CT diastemata in 7 cases, fractured CT in one and a central defect in a worn CT in another. After removing food and exudate from the sinuses, 6 cases were treated successfully by filling the diastema or dental defect with polymethylmethacrylate (PMMA). Following dental extraction, the other 3 cases were treated successfully by use of PMMA alveolar packing. CONCLUSION: Older horses can spontaneously develop oromaxillary fistulae, usually secondary to CT diastemata. In the absence of apical infection, this disorder can usually be treated successfully in standing horses by treating the sinusitis and sealing the oral aspect of the diastema with PMMA. POTENTIAL RELEVANCE: Older horses with sinusitis should be assessed for the presence of CT diastemata and oromaxillary fistulae. If detected, these disorders can be treated successfully in the standing horse.

Oronasal fistula in a 53-year-old hippopotamus (Hippopotamus amphibius).

An oronasal fistula is described in a 53-year-old captive hippopotamus, the animal having shown a nasal discharge, consisting mainly of food particles, during and after feeding for at least 15 years. Necropsy of the emaciated animal revealed an oronasal fistula, measuring 4.5 x 3.5 cm, adjacent to the third left molar tooth, the first and second molars being missing. The fistula was thought to have been caused by an earlier necrotizing alveolitis and osteitis. There was no evidence of rhinitis or aspiration pneumonia. Unrelated findings consisted of a follicular thyroid adenoma and generalized muscle atrophy.

Levator labii superioris muscle transposition to treat oromaxillary sinus fistula in three horses.

OBJECTIVE: To describe surgical transposition of the levator labii superioris muscle to treat oromaxillary sinus fistula in horses. STUDY DESIGN: Clinical study. ANIMALS: Three horses with chronic oromaxillary sinus fistula. METHODS: After severing its tendinous insertion, the muscle belly of the levator labii superioris muscle was retracted and transposed through the oromaxillary sinus fistula. The tendon exited the oral cavity through a full-thickness buccal incision created adjacent to the oral end of the fistula and was then tunneled subcutaneously in a ventral direction before being anchored by sutures to the cheek tissues. RESULTS: Fistulae healed with few complications and with good cosmetic and functional results. CONCLUSIONS: Oromaxillary sinus fistula associated with molariform tooth loss in horses can be treated successfully by transposition of the levator labii superioris muscle. CLINICAL RELEVANCE: Transposition of the levator labii superioris muscle should be considered for resolution of chronic oromaxillary sinus fistula in horses.

Complications of mandibular brachygnathism in a North African leopard.

A 9-year-old, male North African leopard (Panhtera pardus) presented with mandibular brachygnathism and lingually displaced mandibular canine teeth causing a large left oronasal fistula, rhinitis and nasal discharge, and a right orocutaneous fistula. Surgical closure of the left oronasal defect, bilateral mandibular canine tooth crown reduction, and root canal therapy resulted in a positive clinical outcome. A small recurrent left oronasal fistula and the right orocutaneous fistula healed spontaneously after alleviating the occlusal contact with the mandibular canine teeth. At 12-months postoperatively, clinical signs of oral and dental disease had resolved.

Surgical repair of traumatic oronasal fistula in a domestic short-haired cat.

A 9-month-old, spayed female domestic shorthair was presented with a suspected traumatic oronasal fistula. Two surgical attempts using mucosal advancement flaps and single layer closure failed, likely due to inadequate blood supply that was potentially exacerbated by excess tension and trauma on the graft.

Oronasal fistula repair.

Oronasal fistula is a relatively common complication associated with maxillary canine tooth extraction, problematic healing of maxillectomy, and repair of secondary cleft palate in small animals. Regardless of the clinical scenario associated with oronasal fistula, therapy requires surgical treatment. Principles for surgical repair of oronasal fistula include development of mucosal flaps with excellent vascular supply to transpose over the defect to restore continuity of the nasal and oral cavities. The specific surgical technique may vary but includes either single or double mucosal flaps. Oronasal fistula refractory to multiple attempts at surgical repair may be obturated by using a prosthodontic device.

Levator nasolabialis muscle transposition to prevent an orosinus fistula after tooth extraction in horses.

The ventral part of the levator nasolabialis muscle was transposed to the alveolar defect after sinusotomy and tooth extraction in five normal horses and six horses with a tooth root abscess and sinusitis. In the normal horses at weeks 6, 10, 14 and 18, the transposed muscles remained viable and were incorporated into the recipient sites, and orosinus fistulae did not form. Histologically, there was a progressive transition from muscle to fibrous tissue. There was no facial deformity or loss of nasal function at the donor site. A localized abscess was associated with incomplete removal of tooth root fragments in one horse. After 1 year or more, five horses treated for dental disease had complete resolution of clinical signs. One horse continued to have intermittent mild nasal discharge.

The effects of diet on the incidence of periodontitis in rats.

Four groups of 60 male Alpk:APfSD rats were fed different nutritionally comparable diets for 107 weeks with interim sacrifices at 26, 53 and 77 weeks in order to compare the effect of diet on the incidence of oral disease. Changes in the oral and nasal cavities were assessed by histopathology. Oro-nasal fistulation and severe periodontitis were associated with diets containing fibres originating from oats and barley. An expanded ground diet induced the most severe lesions. Aspects of the pathogenesis of the lesions observed are discussed.