Computed tomographic findings in incisors and canine teeth with equine odontoclastic tooth resorption and hypercementosis: a retrospective study in 115 Warmblood horses

Computed tomography (CT) has become a routine method to examine the equine skull. Its clinical use for the diagnosis of diseases of the incisors and canine teeth has not been reported so far. The goal of this study was to study the prevalence and relationship of single CT features and equine odontoclastic tooth resorption and hypercementosis (EOTRH) in equine incisors and canine teeth. In this descriptive retrospective study, helical CT studies of 115 warmblood horses of the age of 5 years or older examined between 2007 and 2020 for reasons unrelated to the incisors and canine teeth were included. Resorption in the crown or root, hypercementosis, widening of the periodontal space, clubbing of the root, lysis of the lamina dura, an abnormal pulp cavity and fracture of the root were recorded in all incisors and canine teeth. The length of the pulp cavity and the labial and lingual/palatal length of the enamel and root was measured in each incisor and canine tooth. Additionally, the angulation was assessed in each incisor. The variable EOTRH was defined based on the presence of resorptive lesions, hypercementosis and clubbing. In result median age of the included horses was 12 years (range, 5-29 years). With regard to the investigated population of horses, 44.3% of all horses had normal incisors whereas 55.7% of the horses had mild EOTRH changes in one incisor at least. Regarding the canine teeth, 54.7% of the horses had normal canine teeth whereas 43.3% horses had mild EOTRH in one canine tooth at least. With regard to all investigated teeth, 868 teeth (53.0%) were classified as normal, whereas 769 incisors and canine teeth (47.0%) showed at least one abnormal CT criterion. Clubbing of the root and hypercementosis were most common (37.1% and 22.7%, respectively) and EOTRH was present in 27.1% of all teeth. Mild changes were more common than moderate or severe abnormalities. In the lower jaw, hypercementosis and widening of the periodontal space at the anatomical root and apex of the root was significantly more frequent (p = 0.004 and 0.02), whereas clubbing of the root was more common in the upper jaw (p = 0.009). In canine teeth, resorption in the anatomical crown and anatomical root, widening of the periodontal space, clubbing and lysis of the lamina dura were significantly more common whereas hypercementosis was more common in incisors (p < 0.001). Frequency of certain CT changes significantly increased from central to middle and corner incisors. Severity of all single CT criteria as well as prevalence and severity of EOTRH significantly increased with age (r = 0.08-0.56). Linear forward and backward multivariate regression analysis confirmed a significant association between prevalence and severity of EOTRH and age, changes of the pulp cavity, widening of the periodontal space at the anatomical root and incisor group (central, middle, corner) (p = 0.01 - < 0.001). In conclusion computed tomographic changes of the incisors and canine teeth are common and age-related in warmblood horses. Therefore, treatment of EOTRH should not be based on diagnostic imaging alone, but always in combination with a thorough clinical examination

The equine gingiva: a gross anatomical evaluation

Equine periodontal disease (ePD) usually starts with food impaction, formation of diastemata, gingival inflammation and formation of periodontal pockets. This process proceeds toward the dentoalveolar space, causing detachment of tooth supporting periodontal fibers. Although several therapeutical procedures have been proposed, ePD is often only diagnosed in advanced stages, requiring dental extraction. A similar dilemma has been observed in small animal medicine, but has been overcome by the introduction of reliable examination protocols for the early diagnosis of periodontal diseases (PD). These protocols are based on detailed anatomical descriptions of healthy gingiva, allowing for the determination of the pathognomonic signs of the onset of PD and providing a basis for grading systems and treatment plans. Consequently, proposals have also been made for periodontal examination protocols in horses. However, these protocols were widely adopted from small animal medicine assuming a similar anatomy of the equine and canine gingiva. To provide a solid anatomical basis for equine specific periodontal examinations, 20 equine heads were examined macroscopically, with special attention to the gingival sulcus, the gingival margin and the interdental papillae. Constant morphological patterns of the gingival margin and the interdental papillae were found for the vestibular and lingual/palatal aspects of the upper and lower cheek teeth arcades, as well as for the incisor arcades. A gingival sulcus measuring greater than 1 mm was present in only 6% of the investigated specimens. The inspection of the gingival margin and the interdental papillae, as well as the recognition of a gingival sulcus, may serve as criteria to establish equine specific periodontal investigation protocols

Die Obwegeser-Cerclagen-Technik für die Behandlung von Kieferfrakturen beim Pferd: Eine retrospektive Studie an 46 Fällen (1987–2010)

Skull fractures, particularly mandibular fractures, are the second most common fractures in horses after limb fractures. The majority of mandibular fractures involves its most rostral part, i.e. the pars incisiva. Like other head fractures, those of the jaws are commonly caused by a blunt external trauma such as a kick from another horse, a fall or a collision with a solid object. Rostral fractures can also occur when horses get caught between vertical metal bars in the stall: the horse bites the bar with its head tilted towards a slightly horizontal position and then suddenly pulls back its head together with a vertical movement of the head, while the teeth remain lodged between the metal bars. In rare cases jaw fractures occuriatrogenically following dental treatment or due to pathological alteration of the bone in case of neoplasia or chronic osteomyelitis. In the majority of cases jaw fractures are open toward the oral cavity and may be severely contaminated. Unstable, bilateral or dislocated fractures which lead to impaired occlusion need surgical intervention. Intraoral wiring is one of the fixation techniques used, depending on the fracture configuration. The Obwegeser multiple-loop intraoral wiring method is particularly suited for fixation of avulsion fractures of the incisors because teeth can be fixed individually, the tension can be distributed evenly among different teeth and the fixation can be extended across a wide area. This method is very suitable for fixation of rostral jaw fractures. It can also be used in combination with other fixation techniques, e.g. plate osteosynthesis, to provide additional stability on the tension side of a fractured mandible and incisor bone. This retrospective study examined 46 patients with jaw fractures that were fixed using the Obwegeser wiring method alone (n=31) or in conjunction with another fixation method (n=15). Medical records, repeated radiological examinations and telephone interviews with the owners were used to gather information about clinical signs on presentation, type of fracture fixation, the healing process, short and long term complications, time of removal of the wires and owner satisfaction with the surgical outcome. The following clinical signs were found with the initial examination: oral haemorrhage (n=28), dysphagia (n=24) and local swelling (n=21). 23 horses suffered from malocclusion and in 5 of 46 patients crepitation was obvious. In 20 cases (43%) the fracture was older than 24 hours at the time of presentation to the hospital. Forty (87%) of the fractures were open. Cases that were fixed using the Obwegeser wiring method alone had a lower complication rate (11/31, 35%) than cases in which wiring was used in conjunction with another fixation method (12/15, 80%). In most cases the fracture could be repaired in the standing horse using sedation and local anaesthesia. An orthopaedic stainless steel wire with a diameter of 1.25 mm was used for cerclage. Wires used alone were left in place for an average of 10 weeks (mean 10.0 and SD±5.8) and those used in addition to another fixation method for an average of 16 weeks (mean 16.0 and SD±8.9). No further complications associated with the fracture occurred in 31 (93%) of the 33 cases that had long-term follow-up information. The fact that in 20 cases (43%) the fracture was older than 24 hours at the time of presentation to the hospital shows that jaw fractures are commonly not recognized immediately or are underestimated by owners or referring veterinarians. The lower complication rate in the 31 cases treated with the Obwegeser wiring method alone may be explained by the lower complexity of the fractures, the intra- versus the extraoral position of the implants and thereby no possible interference of the implant with fracture healing, and the reduced amount of implant material. This study shows that the inexpensive and relatively simple Obwegeser method is a very suitable method for fixation of rostral jaw fractures in the horse

Gingival approach to correct wry nose using locking compression plates in two foals

Wry nose (campylorrhinus lateralis) in foals leads to breathing and weaning problems as well as reduced performance. The objective of this retrospective study was to describe a new gingival approach for, and report the outcome after, surgical correction of wry nose in two foals. Two young foals with wry nose were surgically treated using a gingival approach. Osteotomy of the incisive and maxillary bones was carried out, and a 3.5-mm locking compression plate (LCP) with screws was inserted in the incisive and maxillary bones and in several teeth to stabilise the gap. The rostral part of the nasal septum was resected, and osteotomy and plate fixation were used to correct the nasal bone deviation. A 2.4-mm UniLOCK plate was used in one foal and 2.7-mm LCP in the other. Respiratory difficulties and facial malformation were markedly reduced in both foals. The existing brachygnathia superior and nasal bone deviation could not be completely eliminated. Main limitation was the small sample size of only two foals. In conclusion surgical correction of wry nose through a gingival approach resulted in a good outcome with a significant reduction in the deviation and associated clinical signs

Clinical, radiographic and histologic findings, therapy and outcome in 15 horses with suture periostitis: a case series

There are few reports describing suture periostitis (SP) in horses. This case series outlines the clinical, radiographic and histologic features of SP and compares various types of treatment in 15 horses presented to the Equine Clinic, Vetsuisse-Faculty, University of Zurich. Overall, the incidence of horses with SP presented to our clinic was low, and clinical signs were similar to those previously reported. Radiography was used to diagnose SP, but computed tomography was the imaging modality of choice for determining the extent of the bony changes and the suture lines affected. Horses that underwent surgical stabilization had more rapid resolution of signs than those treated conservatively or not treated at all