Commissurotomy Using Carbon Dioxide Laser in 67 Dogs.

Commissurotomy is a surgical technique whereby the lip commissure is incised. Indications for commissurotomy include cheiloplasty, partial commissurectomy, or access to the caudal portion of the maxilla or mandible for oral surgery. Carbon dioxide (CO2) laser was used for commissurotomy in dogs for partial commissurectomy (n = 7) or access for oral surgery (n = 60). All dogs had oral or maxillofacial neoplasms that required resective surgery. The CO2 laser was used to perform commissurotomy or commissurectomy, as indicated. Commissurotomy healing was evaluated at 2 weeks with longer-term follow-up of a minimum of 6 weeks (104.6 ± 99.2 weeks) postoperatively. Postoperative complications related to commissurotomy (n = 6) included mucosal dehiscence (n = 3) less than 1.5 cm, lip margin dehiscence (n = 2) less than 1.0 cm, and complete commissurotomy wound dehiscence (n = 1). Two wound dehiscence cases, including the complete wound dehiscence, had uncomplicated healing following revision surgery. Minor marginal and mucosal dehiscence cases healed by the second intention. Periwound edema ranged from mild to severe and resolved by the 2-week postoperative examination. Statistical analysis showed that complications associated with commissurotomy/commissurectomy were independent of the type of surgical procedure, tumor type, and surgical margin evaluation when using the CO2 laser. Commissurotomy using CO2 laser provided rapid and unimpeded exposure with minimal hemorrhage of the caudal maxilla and mandible for resective oral and maxillofacial surgery.

Assessment of Extractions of Deciduous Mandibular Canine Teeth to Correct Linguoversion Malocclusion in 17 Dogs.

A search of medical records at the Center for Veterinary Dentistry and Oral Surgery, Gaithersburg, MD was conducted to identify patients who received extractions of deciduous mandibular canine teeth to treat linguoversion. Patients were included if they were less than 5.5 months of age and had a diagnosis of deciduous class 2 or bilateral class 1 malocclusions. Treatment was considered a success if normocclusion of the permanent dentition was achieved at follow up evaluation. Seventeen patients represented 13 different breeds. No significant correlation was seen between age of treatment (mean age 3.34 months) or sex (11 males, 6 females). Six patients had class 1 malocclusions (35.29%) and eleven patients had class 2 malocclusion (64.71%). Of the six dogs treated for class 1 malocclusions, two had traumatic palatal contact and four had only minor soft tissue contact. Eleven cases of class 2 malocclusion were treated and of these there was one mild, six moderate, and four severe cases of mandibular distocclusion. All cases treated for class 1 malocclusions had a successful outcome resulting in permanent normocclusion (100%), while class 2 malocclusions had success in three of eleven cases (27.27%). The outcomes based on occlusion type were determined to be significant (p = 0.009). All participants had immediate relief of soft tissue trauma and no significant side effects of treatment were recorded. The results show that extractions of deciduous linguoverted mandibular canine teeth (LMC) can immediately improve traumatic impingement and may be a factor in providing a comfortable and functional adult occlusion. Further investigation with a larger sample size would be warranted.

Risk Factors for Failure of Hard Palate Mucoperiosteal Flap Repair of Acquired Oronasal Communication in Dogs: A Pilot Study.

The objective of this retrospective pilot study was to describe potential risk factors for failure of hard palate mucoperiosteal flaps (HPF) transposed for closure of oronasal communication. Dogs (n = 28) with acquired oronasal communication defects were included in the study population. Functional success of an HPF was determined by visual inspection at the last examination and lack of clinical signs. Risk factors for HPF failure including age, sex, body weight, presence of neoplasia at the time of surgery, presence of neoplasia after surgery due to incomplete or narrow margins, use of CO2 laser, previous surgeries in the same location, HPF blood supply, size of the HPF as a percentage of the total area of the hard palate mucoperiosteum, and distance traveled by the apex of the HPF were evaluated using descriptive statistics and unadjusted logistic regression modeling. Seven out of 28 (25%) hard palate flap procedures resulted in persistent oronasal communication and were considered failures. Body weight (Median: 17 vs. 25 kg, OR = 0.94, 80% CI = 0.90, 0.99), presence of neoplasia at the time of surgery (86 vs. 57%, OR = 4.50, 80% CI = 1.01, 20.06), HPF area (Median: 0.49 vs. 0.41, OR = 84.40, 80% CI = 1.66, 4,298) and apex travel distance (Median: 2.06 vs. 0.67, OR = 5.15, 80% CI = 2.14, 12.38) were associated with flap failure. Within this sample, the presence of neoplasia at the time of initial surgery, increasing the area of the HPF, and distance traveled by the HPF apex were associated with a greater odds of HPF failure. Further studies with larger sample sizes are needed to confirm repeatability of these results. HPFs remain a viable surgical option for closure of oronasal communication. Careful surgical planning, strict adherence to surgical principles, and awareness of anatomical limitations can increase the likelihood of success.

Localization of the First Mandibular Molar Roots in Relationship to the Mandibular Canal in Small Breed Dogs-A Tomography Imaging Study.

The intimate relationship between the mandibular canal (MC) and the first mandibular molar tooth presents challenges when performing dentoalveolar surgical procedures due to the probability of causing iatrogenic injury to the inferior alveolar neurovascular bundle. Superimposition between the MC and the first molar (M1) tooth roots is often observed on intraoral dental radiographs in small breed dogs. However, due to the radiograph's bidimensional nature, it is impossible to determine the buccal or lingual localization of the first molar roots with respect to the MC. Thus, this study's objective was to determine the localization of the first molar tooth's roots in relation to the position of the MC and their overlapping percentage with the canal in small-bodyweight dogs (<15 kg) using tomographic diagnostic images. For this, cone-beam computed tomography and high-definition computed tomography exams from 103 small breed dogs (under 15 kg) were retrospectively assessed to determine the lingual or buccal localization of the first molar tooth's roots with respect to the MC and the degree of overlap of the roots with the canal. In conclusion, most of the roots of M1 of dogs under 15 kg were located at the MC's lingual aspect (82.7%) with an overall superimposition median with the MC of 100 and 90% for the mesial and distal roots, respectively. Straddle tooth roots were not a common anatomical presentation in the dogs of this study.

Curative Intent Surgery of Oral Malignant Melanoma and Regional Lymph Node Biopsy Assessment in 25 Dogs: 2006-2017.

Medical records were searched for dogs that had received curative intent surgery for oral malignant melanoma and ipsilateral excisional regional lymph node biopsy. Twenty-seven dogs were operated on and 25 dogs of these dogs met the inclusion criteria of signalment, post-excision margin status, presence of metastasis for each biopsied lymphocentrum, survival time post-excision, presence of recurrence or metastasis at follow-up or at death/euthanasia, location of the primary tumor, and any postoperative adjuvant treatment. These 25 dogs had complete tumor excision with tumor-free margins and 19 (76%) had postoperative adjuvant therapy. Median survival time after excision for the dogs in this study was 335.5 days. Results of this study support previous work that documents prolonged survival time following complete excision of oral malignant melanoma with tumor-free surgical margins in dogs. Additionally, 4 dogs (16%) had histologically confirmed regional lymph node metastasis at the time of definitive surgery.

Validation of Regional Lymph Node Excisional Biopsy for Staging Oral and Maxillofacial Malignant Neoplasms in 97 Dogs and 10 Cats (2006-2016).

The objective of this retrospective clinical study was to confirm the validity of excisional biopsy of regional lymphocentrums for staging oral and maxillofacial neoplasms in a population of 97 dogs and 10 cats. Patients diagnosed with oral and maxillofacial malignant neoplasms underwent ipsilateral excisional biopsy of the mandibular, parotid, and medial retropharyngeal lymphocentrums that receive afferent drainage from the oral and maxillofacial region followed by curative intent surgery of the neoplasm. Biopsy specimens and the resected neoplasm were submitted to a commercial pathology laboratory for histopathologic assessment. The incidence of metastasis to one or more regional lymphocentrums was 14.0%. Of the cases with metastatic disease, 26.7% did not involve the mandibular lymphocentrum. Although the incidence of regional lymph node metastasis was less than reported previously, regional lymph node assessment is warranted in cases of oral and maxillofacial neoplasia.

Traumatic Intrusion of a Maxillary Canine Tooth: 3 Cases.

Of the six recognized types of tooth luxation injuries, intrusion generally carries the most guarded long-term prognosis due to the high risk of complications, including root resorption, ankylosis, marginal bone loss, and pulp canal obliteration or necrosis. The degree of traumatic intrusion and stage of root development affects the outcome and treatment planning. This report describes the clinical history, oral and radiographic examination findings, and rationale for surgical extraction in 2 dogs and 1 cat with traumatic intrusion of a maxillary canine tooth.

Resection of mast cell tumor of the lip in a dog.

A 10-year-old Boston terrier dog was presented for treatment of a 2-cm mast cell tumor of the left upper lip and nasal planum immediately adjacent to the philtrum and ventral to the nares. CO2 laser was used for resection of the lesion. Wound reconstruction was performed using bilateral labial advancement flaps.

Bilateral maxillary periodontal ligament hamartoma in a dog.

A 12.5-year-old dog was presented for severe periodontal disease and bilateral maxillary enlargement. Radiographs of the maxilla showedgeneralized root resorption, ankylosis, and rarefaction of bone with focal radiodense areas. Surgical tooth extraction of multiple maxillary teeth and bilateral incisional biopsies of the periodontal tissue and maxilla in the region of the maxillary fourth premolars were performed. Histopathologic examination showed features typical of fully differentiated periodontal ligament with abundant cementum/alveolar lining bone and sparce odontogenic epithelial cell rests. Histopathology in conjunction with radiographic and clinical signs suggested a diagnosis of bilateral periodontal ligament hamartoma. Examination 3-months postoperatively indicated uncomplicated healing of the extraction and biopsy sites with no resolution of the maxillary enlargement.

Bilateral ectopic ureters in a male dog with unilateral renal agenesis.

A 1-year-old neutered male mixed-breed dog was evaluated because of signs of urinary incontinence. Retrograde positive contrast urethrocystography and excretory urography with pneumocystography revealed bilateral intramural ectopic ureters and absence of the right kidney. During abdominal exploratory surgery, only the left kidney was located. The left intramural ectopic ureter was repaired by neoureterostomy (creation of a new opening for the ureter to enable urine to empty into the bladder). The right ectopic ureter was ligated at its entrance into the urinary bladder serosa. Results of excretory urography (performed immediately after surgery and repeated 8 weeks later) revealed successful correction of the left intramural ectopic ureter. Twelve weeks after surgery, the dog remained continent. To the authors' knowledge, there are few reports of ectopic ureters in male dogs; furthermore, the urinary tract abnormalities detected concurrently in this dog are also unusual.