Normal variation of clinical mobility of the mandibular symphysis in cats.

Introduction: The primary objective of this retrospective study was to document the normal variation of clinical mobility of the mandibular symphysis in cats and possible associations with bodyweight, age, sex, sexual status, breed and skull morphology. Secondarily, the radiographic appearance of the mandibular symphysis and possible associations with the analyzed data were evaluated. Materials and methods: Two hundred and sixteen cats of 15 different breeds that underwent maxillofacial, oral and dental procedures from April 2015 to December 2021 were included. Clinical mobility was evaluated under general anesthesia using a 0 to 3 scale in lateromedial (LM) and dorsoventral (DV) directions. The symphysis was radiographically classified on the occlusal radiographic view of the rostral mandibles as fused or open, and with parallel or divergent margins. Results: Bodyweight ranged from 2.2 to 12.5 kg (median 4.0 kg), age from 4 months to 17 years and 4 months (median 6 years and 4 months). At the first evaluation DV symphyseal mobility was 0 in 177 cases (82%), 1 in 32 cases (14.8%) and 2 in 7 cases (3.2%), LM mobility was 0 in 61 cases (28.3%), 1 in 110 cases (50.9%) and 2 in 45 cases (20.8%). 81.1% of the radiographs were included in the statistical analysis. Three symphyses (1.6%) were classified as fused and 190 (98.4%) as open, 129 (68.8%) having divergent margins and 61 (31.6%) parallel. One hundred and forty-eight cases (76.7%) did not show the presence of odontoclastic replacement resorption on the canine teeth (TR subgroup 1), 23 (11.9%) showed stage ≤3 lesions (TR subgroup 2) and 22 (11.4%) stage 4 lesions (TR subgroup 3). Logistic regression models exploring factors that affected DV and LM mobility were statistically significant (p < 0.0001; p < 0.0001) with an increase in LM mobility predicting an increase in DV mobility, and vice versa. An increase in DV mobility was associated with an increase in age and in having resorptive lesions. A decrease in LM symphyseal mobility was associated with being brachycephalic. Conclusion: The great majority of cases showed some degree of LM symphyseal mobility, and 18% showed DV mobility. Symphyseal bony fusion is rare but possible.

Clinical, radiographic and histological findings of seven teeth from two California sea lions (Zalophus californianus) housed under professional care.

Seven teeth extracted from two adult California sea lions (Zalophus californianus) due to pulp exposure and/or to gain access to the mandibular canine teeth were histologically evaluated, and the findings were compared with clinical and radiographic findings. Three teeth were diagnosed with pulp exposure, and two of these showed no radiographic signs of endodontic disease and were histologically vital with prominent coronal pulpitis and a pulp polyp. Another tooth with pulp exposure was showing clinical and radiographic signs of endodontic disease and was histologically confirmed with pulp necrosis. A discoloured incisor tooth was showing radiographic signs of endodontic disease and was also histologically non-vital. Two clinically and radiographically healthy mandibular first premolar teeth and one second incisor tooth had no evidence of pulpitis or pulp necrosis but had pulp canal obliteration. Regular clinical and radiographic follow-up for 5 months to 3 years after the procedures confirmed uneventful healing of the extraction sites, despite initial flap's dehiscence. Although extractions of affected teeth in California sea lions are considered the most practical and beneficial therapy, these are associated with the risks of extensive trauma and anaesthesia and the need to perform these surgical procedures on-site under variable conditions. As California sea lions can be trained to allow conscious dental radiographic re-checks, monitoring teeth with clinical signs of pulp polyp formation and without radiographic signs of endodontic disease warrant further evaluation/reconsideration from previous recommendations. Endodontic treatment of abscessed teeth in California sea lions is reportedly unsuccessful and is discouraged. However, vital pulpectomy could be an alternative treatment to extraction in teeth with pulp polyps as it was found to be highly successful in humans, but the possibility of endodontic failure and need for further treatments should be weighted in the treatment choice.

Normal variation of clinical mobility of the mandibular symphysis in dogs.

Introduction: The primary objective of this retrospective study was to document the normal variation of clinical mobility of the mandibular symphysis in dogs, and evaluate possible associations with breed, bodyweight, age, sex, and skull morphology. Secondarily, the radiographic appearance of the mandibular symphysis and possible associations with the analyzed data were also evaluated. Methods: Medical records of dogs that underwent anesthetic procedures for maxillofacial, oral and dental evaluation from April 2015 to December 2021 were included. Results: 567 dogs of 95 different breeds were included, with a total of 695 evaluations. Body weight ranged from 0.8 kg to 79 kg (median 14.4 kg) and age from 3 months to 16 years and 4 months (median 6 years and 9 months). Clinical mobility was evaluated under general anesthesia using a 0 to 3 scale, in lateromedial (LM) and dorsoventral (DV) directions. The symphysis was radiographically classified as being fused or open. The open symphyses were further radiographically divided in having parallel or divergent margins. At the time of the first evaluation DV mobility was 0 in 551 cases (97.2%) and 1 in 16 cases (2.8%). LM mobility was 0 in 401 cases (70.7%), 1 in 148 cases (26.1%) and 2 in 18 cases (3.2%). There was not a significant change in mobility over time for cases examined more than once (P= 0.76). All cases had an intraoral radiographic examination. 83.8% of the radiographs were included in the statistical analysis. Two symphyses (0.4%) were classified as fused and 473 (99.6%) as open, 355 (74.7%) having divergent margins and 118 (24.8%) parallel margins. Logistic regression models exploring factors that affected DV and LM mobility were statistically significant (P < 0.0001; P < 0.0001), with an increase in LM mobility predicting an increase in DV mobility, and vice versa. An increase in age and in bodyweight was associated with a decrease in mobility. There was no statistical difference in clinical mobility across specific breeds or sexes. Increased probability of a divergent symphysis and increased DV mobility was found to be associated with a brachycephalic conformation. The increase in LM mobility was comparatively higher in small brachycephalic breeds compared with larger brachycephalic breed. Discussion: The majority of the cases showed little to no mobility of the mandibular symphysis and radiographically bony fusion can be rarely seen.

Radiographic, MRI, and CT findings in a young dog with Becker-like muscular dystrophy.

An 8-month-old, male, crossbreed dog was presented for macroglossia, reduced mandibular extension, ptyalism, dysphagia, and regurgitation. Serum creatine kinase and aspartate aminotransferase activity were markedly increased. Thoracic radiographs showed an axial gastro-esophageal hiatal hernia, diaphragmatic thickening, and asymmetry. Magnetic resonance imaging of the head showed a severely enlarged tongue, symmetric increase in size of the geniohyoid and mylohyoid muscles, and diffuse masticatory hypomyotrophy. Whole-body CT ruled out other musculoskeletal abnormalities and further characterized the radiographic and MRI findings. Muscular histopathology was consistent with Becker muscular dystrophy.

Management of bilateral pterygoid myositis ossificans-like lesion in dogs.

Myositis ossificans (MO) and myositis ossificans-like lesions have been rarely described within the veterinary literature, and are even less common in the maxillofacial region. When MO affects the muscles of mastication, it can result in complete or partial inability to open the mouth. As with other conditions resulting in decreased or restricted mandibular range of motion, severe and potentially fatal sequelae such as difficulty with prehension, swallowing, and air exchange are possible. Diagnostic imaging is essential in achieving an accurate diagnosis and in formulating an appropriate treatment plan. In this "method" manuscript, we provide a detailed description of our approach to diagnosis and surgical management of MO-like lesions of the pterygoid muscles and describe our experience with two young French bulldogs.

A Clinical, Radiographic and Histological Study of Unerupted Teeth in Dogs and Cats: 73 Cases (2001-2018).

Lack of dental eruption may be accompanied by development of dentigerous cysts and has also been rarely associated with neoplasia. However, little information is available on prevalence of unerupted teeth and associated lesions in dogs and cats. The main objective of this study was to describe the epidemiologic data of canine and feline dental patients with unerupted teeth, and assess the prevalence of associated dentigerous cysts and tumors. Secondary aims included the evaluation of possible factors implicated in cystic development, and description of the histological features of dentigerous cysts. Medical and dental records, intraoral photographs, intraoral radiographs of client-owned dogs and cats with clinically missing teeth examined between 2001 and March 2018 were reviewed. Collected data included signalment, reason for presentation, number, type, depth of inclusion and angulation of unerupted teeth, presence of cystic lesions or tumors, abnormalities affecting involved teeth, histopathological findings, performed treatment and outcome. Seventy-three animals (69 dogs and 4 cats) with 113 unerupted teeth were included. The most frequent unerupted tooth in dogs was the first premolar teeth (78%), followed by the canine and third molar teeth. Dentigerous cysts were diagnosed associated with 48 (44.4%) teeth in dogs and one out of five unerupted teeth in cats. The affected teeth in dogs were predominantly in horizontal inclination (40%) and in soft tissue inclusion (77%). Brachycephalic canine breeds were overrepresented. The only unerupted tooth in boxer dogs was the first premolar tooth (32 teeth). Ninety percentage of boxers with unerupted teeth developed associated lesions (25 dentigerous cysts and one tumor). Two ameloblastomas (one in a dog and one in a cat) and one osteosarcoma (in a dog) were diagnosed in association with three unerupted teeth. Histology was essential in diagnosing two odontogenic cysts not evident on radiographs. In all cases that were followed-up, treatment (i.e., extraction, extraction and surgical curettage, or operculectomy) appeared successful. Untreated dentigerous cysts showed progression at re-examination. None of the unerupted teeth without evidence of cyst at the time of diagnosis showed incipient cystic development. None of the evaluated factors were associated with lack of eruption and/or development of associated lesions.

Skull pathology in 10 cats with patellar fracture and dental anomaly syndrome.

CASE SERIES SUMMARY: The aim of this case series is to describe the clinical and radiological features of mandibular and maxillary abnormalities in cats diagnosed with patellar fractures and dental anomalies, a condition that we have named 'patellar fracture and dental anomaly syndrome' (PADS), also known previously as 'knees and teeth syndrome'. Where available, clinical records, skull and/or intraoral dental radiographs, head CT images, microbiology and histopathology reports were collected, and follow-up was obtained. Ten cats with mandibular or maxillary abnormalities were identified. Common clinical features included multiple persistent deciduous teeth, gingivitis and swellings of the jaw. Skull radiographs were available for 7/10 cats and head CT images were available for one cat. Findings included marked bony and periosteal proliferation, hypodontia, root resorption, root malformation and unerupted permanent teeth. Where available, microbiology and histopathology results were consistent with osteomyelitis. RELEVANCE AND NOVEL INFORMATION: Mandibular and maxillary abnormalities are an additional unreported clinical feature of the rare condition that we have termed PADS. Radiologically, these lesions can have an aggressive appearance, which can mimic neoplasia. Medical management with antibiotic and anti-inflammatory therapy improves clinical signs in the short term; however, surgical extraction of persistent deciduous and unerupted permanent teeth, and debridement of proliferative and necrotic bone appear to be necessary for an improved outcome. Additional information on long-term outcome is required.

Open-mouth jaw locking in cats: a literature review and use of CT in three cases.

CASE SERIES SUMMARY: This report summarises and reviews the published cases of open-mouth jaw locking in cats and describes three further cases. Case 1 was a 5-year-old, 5.3 kg male neutered domestic shorthair cat. CT identified changes consistent with temporomandibular joint (TMJ) dysplasia with osseous degenerative changes, and the cat subsequently underwent bilateral partial zygomectomy with bilateral partial coronoidectomy. Case 2 was a 10-year-old, 6.0 kg male neutered Exotic Shorthair. Aside from a fracture of the left maxillary canine tooth crown and absence of the left maxillary fourth premolar tooth, no abnormalities were found on CT scan. The cat also underwent bilateral partial zygomectomy with bilateral partial coronoidectomy. The third case was a 1-year-old, 4.0 kg male neutered Persian cat. Changes on CT were consistent with bilateral TMJ dysplasia, and the cat underwent staged bilateral partial zygomectomy with bilateral partial coronoidectomy. There was no recurrence of open-mouth jaw locking in any of the cases on long-term follow-up. RELEVANCE AND NOVEL INFORMATION: Open-mouth jaw locking has been reported in cats of a wide range of ages, from 1-10 years. Cats with all skull types (brachycephalic, mesaticephalic and dolichocephalic) may be affected, but brachycephalic breeds seem to be over-represented. A CT scan with the jaw locked in place is recommended for diagnosis and surgical planning purposes; two of the cases reported here document the first cases of TMJ dysplasia in cats to be definitively diagnosed using CT. Trauma and symphyseal or TMJ laxity may also predispose to development of the condition. Partial coronoidectomy and partial zygomatic arch resection performed alone or in combination are generally successful at preventing recurrence. Bilateral partial zygomectomy with bilateral partial coronoidectomy has not previously been reported as a surgical treatment, and is recommended when open-mouth jaw locking occurs bilaterally.

Vertical Mandibular Range of Motion in Anesthetized Dogs and Cats.

The main movement of the temporomandibular joint of dogs and cats is in vertical dimensions (opening and closing the mouth). An objective evaluation of the vertical mandibular range of motion (vmROM) may favor early diagnosis of a number of conditions affecting the joint mobility. vmROM, corresponding to the maximum interincisal opening, was measured in 260 dogs and 127 cats anesthetized between June 2011 and April 2015 because of oral or maxillofacial problems and procedures. Animals with a known history of or having current diseases considered to hamper mandibular extension were excluded from the study. Dogs were divided into four subgroups, based on body weight: subgroup 1 (≤5.0 kg, 51 dogs), subgroup 2 (5.1-10.0 kg, 56 dogs), subgroup 3 (10.1-25 kg, 66 dogs), and subgroup 4 (>25.1 kg, 87 dogs). The mean vmROM of all dogs was 107 ± 30 mm (median 109, range 40-180); in subgroup 1 was 67 ± 15 mm (median 67, range 40-100), in subgroup 2 was 93 ± 15 mm (median 93, range 53-128), in subgroup 3 was 115 ± 19 mm (median 116, range 59-154), and in subgroup 4 was 134 ± 19 mm (median 135, range 93-180). The mean vmROM of the cats was 62 ± 8 mm (median 63, range 41-84). Correlations between vmROM, age, sex, and body weight were evaluated. In dogs, vmROM did not correlate with age, and in cats a weak positive correlation was found. vmROM and body weight were positively correlated in both populations, except dog subgroup 2. Overall, mean vmROM and body weight were significantly higher in male than in female, both in dogs and in cats. However, vmROM did not differ between sexes in any of the canine subgroups, and only in subgroup 4 male dogs were significantly heavier than females. Evaluation of vmROM should be incorporated into every diagnostic examination as it may be valuable in showing changes over time for every single patient.

Caudal mucogingival lesions secondary to traumatic dental occlusion in 27 cats: macroscopic and microscopic description, treatment and follow-up.

The main aim of this retrospective study was to describe clinical and histopathological findings in cats with mucogingival lesions developed at the contact point of the premolar and molar teeth of the opposite quadrant. Cases were retrieved following manual review of the medical records, dental records and photographic documentation of all feline dental patients visited in the period between February 2001 and August 2011. Cats showing different lesions at different times were calculated as multiple cases. A total of 27 cats (31 cases) with 44 lesions (26 proliferations [59%], 11 clefts [25%] and seven foveae [16%]) were included. Mean age at the time of the first visit was 6.6 years. The lesion object of the study was the main reason for presentation in only five cases (16%). Proliferations showed two different histopathological patterns and had characteristics in common with human oral pyogenic granuloma. Successful treatment was achieved in all cases by removing the occlusal contact by dental extraction or coronal reduction, possibly associated with lesion excision. This study underlines the need for a thorough oral examination and evaluation of dental occlusion in all patients. Causes for the development of traumatic occlusion may include an acquired overbite (possibly secondary to selective dental extraction), congenital or post-traumatic malocclusion, abnormal latero-lateral mobility of the mandible, occlusal drift of the premolar and molar teeth, and/or alveolar bone expansion.

Sublingual reactive histiocytosis in a dog.

Lingual lesions are relatively uncommon in dogs and are mostly represented by neoplasms and glossitis secondary to trauma or infections. Reactive histiocytosis is an uncommon, poorly understood, reactive disorder characterized by proliferation of activated, interstitial, dendritic, antigen-presenting cells associated with lymphocytes and neutrophils with a specific angiocentric orientation and occasional angioinvasion and angiodestruction. Clinically, the disease has a waxing and waning behavior with possible response to treatment and regression, or progression to multiple lesions and internal organ involvement. This case report describes an unusual sublingual presentation of reactive histiocytosis in a Miniature Pinscher dog. The diagnosis was obtained by clinical and histopathological exclusion of other causes, detection of the characteristic microscopic growth pattern, and by immunocytochemistry. Histiocytic cells were vimentin, CD18, CD11c, and CD1c positive consistent with a dendritic cell origin. Anti-BCG stain (Bacillus Calmette and Guerin) was negative for etiological agents. The dog was treated with oral administration of tetracycline and niacinamide during an 8-month period. There was no indication of recurrence of the sublingual mass 2-years following treatment.

Mandibular periostitis ossificans in immature large breed dogs: 5 cases (1999-2006).

This case series describes clinical, radiographic, and histopathological features of mandibular swellings in 5 immature, large breed dogs. The dogs originated from different regions of the United States. In each case, intraoral dental radiography of the jaw swelling revealed a two-layered (double) ventral mandibular cortex. Biopsy was performed in 4 of the 5 puppies, revealing periosteal new bone formation. Resolution of the mandibular swelling was spontaneous in the 4 dogs available for follow-up examination. The authors postulate that the clinical, radiographic, and histopathological presentation of mandibular swelling in these 5 dogs is a distinct pathological entity consistent with an inflammatory condition of the maturing human mandible known as periostitis ossificans.

Hemisection and partial retention of carnassial teeth in client-owned dogs.

Nine client-owned dogs presented with periodontally and/or endodontically involved mandibular or maxillary carnassial teeth that were either individually affected or adjacent to a jaw fracture. A total of 10 teeth were hemisected (8 mandibular first molar teeth and 2 maxillary fourth premolar teeth), and one crown-root segment was extracted for each tooth. Gingival tissues were approximated and sutured over the extraction sites, and the retained tooth portions were treated by means of standard root canal therapy or vital pulp therapy followed by standard root canal therapy. Retained crown-root segments of 2 of the 10 hemisected teeth were extracted following short- and long-term postoperative examinations due to continued periodontal complications. It was concluded that resection of a portion of a tooth can be a useful treatment for periodontally and/or endodontically involved carnassial teeth that are affected individually or located adjacent to a jaw fracture in dogs.