Equine

There are many possible causes for this problem. The same applies to the possible consequences. These vary from harmless—the problem resolves itself—to a worst-case scenario with a subsequent hospital stay and five-figure costs for the necessary follow-up treatment. The therapeutic spectrum is equally variable.
The causes and consequences can be divided into different categories

1. Iatrogenic trauma
2. Absolute and relative ‘intensive’ changes to the natural tooth shape with a 2° loss of function = over-floating, and its effects.
3. Unfortunate chain of circumstances – no specific cause can be verified

Group 1 largely consists of manual errors, some of which are individual and some of which are caused by a certain systemic error resulting from the instrumental equipment. There is no age-specific occurrence here. 1.5. is a problem that, according to osteopaths' reports, occurs much more frequently than is commonly assumed. There are no valid figures on this topic to date. However, it seems obvious to note here that the less I have to open the horses mouth while working, the lower the risk of problems with the temporomandibular joint structures. There are a number of ways to counteract this.
Therapeutically, the range extends from spontaneous healing or short-term temporary use of NSAIDs to costly follow-up treatments with computed tomography and complex surgical intervention.
Group 2 primarily consists of 2° functional disorders resulting from absolute and/or relative overfloating. Young horses are only affected by this problem in exceptional cases. This makes it all the more difficult to predict the effects of the method, because ageing horses (>15 years) increasingly lose their reserve capacity. Another problem is local subclinical and clinically significant pre-existing damage in ageing horses. This group of patients can react promptly and violently to further functional limitations. The interesting thing about this group is that they demonstrating the possible effects of our treatment and at the same time they can inspire us to think about fundamental issues. The therapy for these cases is very individual and simple NSAID administration is rarely successful. Here, too, very cost-intensive follow-up treatments may be necessary.
In summary, we should be aware that a significant proportion of ‘routine dental treatment’, is performed on clinically healthy horses. Here, more than anywhere else, the rule primum non nocere applies.
However, complications that arise can also help us to rethink and improve our working methods in the long term. However, this only happens if we deal with them appropriately. Last but not least, the algorithm of ‘evidence collection’ is also important, as it is not only of interest to science but also relevant to possible forensics.

Introduction: Headshaking in horses is a commonly encountered syndrome, recognized
by spontaneous and often repetitive uncontrolled movements of the head and neck, which can occur intermittently or persistently (Newton, 2005; Madigan & Bell, 2001). The majority of horses presenting with signs of headshaking are diagnosed with trigeminal-mediated headshaking (Pickles et al., 2014). Other causes can be local diseases such as dental problems, periapical dental osteitis, rhinitis, intranasal masses, and sinusitis (Pickles at al. 2014; Newton et al. 2000; Gilsenan et al. 2014) infraorbital canal changes (Edwards et al. 2019). We couldn’t find publication considering supernumeric tooth induced headshaking. Our objective is to present a successfully treated headshaking caused by a non-erupted supernumeric and other misaligned incisors. Materials and methods: A 12 years old dutch warmblood showing spontaneous, intermittent and repetitive vertical/horizontal movements of the head and neck during exercise. Priorly the horse had detailed physical and edoscopic examination at different clinics. Nose cover was used by the owner without satisfactory result. Former examinations diagnosed misaligned, mispositioned, malformed 102-103 and a remnant 503. At our clinic x-ray of the incisors and transverse CT images of the head were acquired on a standing sedated horse from the occipital region until the incisors. The images revealed a non-erupted supernumerary incisor positioned deeply within the right incisive bone, thinning and bulging out the dorsal compacta of the bone at the alar fold region. The right sided infraorbital nerve block caused mild improvement. The CT did not reveal any other changes in the rest of the head that could correlate to the actual headshaking condition. Based on the results we decided to extract the 503 remnant, the 102-103 and the supernumeric incisor. The surgery was performend on a standing sedated (0,01 mg/bwkg Detomidin-hydroclorid and 0,01 – 0,02 mg/bwkg butorphanol) horse using infraorbital nerve block and local lidocaine infiltration. For packing platelet rich plasma covered with calcium/sodium alginate were used and changed 2-4 days intervalls until the granulation level made the packing unnecessary. For oral hygiene 0,2% chlorhexidine was used twice daily. NSAID and combinated penicillin were administerd in the first 5 days following extraction. Results: 2,5 months after the operation the horse could start working again without any signs of headshaking. Conclusions: In the horse, clinical signs attributed to supernumerary incisor teeth are rarely noted and therefore treatment is not sought (Baker 1991; Dixon et al.1999b; Baker 1999). Although we could not prove 100% our final diagnosis but the negative results of the complex examinations focusing on the frequent causes of the headshaking turned us towards the pathological conformity of the incisors including the supernumerary one.

Introduction: Headshaking in horses is a commonly encountered syndrome, recognized
by spontaneous and often repetitive uncontrolled movements of the head and neck, which can occur intermittently or persistently (Newton, 2005; Madigan & Bell, 2001). The majority of horses presenting with signs of headshaking are diagnosed with trigeminal-mediated headshaking (Pickles et al., 2014). Other causes can be local diseases such as dental problems, periapical dental osteitis, rhinitis, intranasal masses, and sinusitis (Pickles at al. 2014; Newton et al. 2000; Gilsenan et al. 2014) infraorbital canal changes (Edwards et al. 2019). We couldn’t find publication considering supernumeric tooth induced headshaking. Our objective is to present a successfully treated headshaking caused by a non-erupted supernumeric and other misaligned incisors. Materials and methods: A 12 years old dutch warmblood showing spontaneous, intermittent and repetitive vertical/horizontal movements of the head and neck during exercise. Priorly the horse had detailed physical and edoscopic examination at different clinics. Nose cover was used by the owner without satisfactory result. Former examinations diagnosed misaligned, mispositioned, malformed 102-103 and a remnant 503. At our clinic x-ray of the incisors and transverse CT images of the head were acquired on a standing sedated horse from the occipital region until the incisors. The images revealed a non-erupted supernumerary incisor positioned deeply within the right incisive bone, thinning and bulging out the dorsal compacta of the bone at the alar fold region. The right sided infraorbital nerve block caused mild improvement. The CT did not reveal any other changes in the rest of the head that could correlate to the actual headshaking condition. Based on the results we decided to extract the 503 remnant, the 102-103 and the supernumeric incisor. The surgery was performend on a standing sedated (0,01 mg/bwkg Detomidin-hydroclorid and 0,01 – 0,02 mg/bwkg butorphanol) horse using infraorbital nerve block and local lidocaine infiltration. For packing platelet rich plasma covered with calcium/sodium alginate were used and changed 2-4 days intervalls until the granulation level made the packing unnecessary. For oral hygiene 0,2% chlorhexidine was used twice daily. NSAID and combinated penicillin were administerd in the first 5 days following extraction. Results: 2,5 months after the operation the horse could start working again without any signs of headshaking. Conclusions: In the horse, clinical signs attributed to supernumerary incisor teeth are rarely noted and therefore treatment is not sought (Baker 1991; Dixon et al.1999b; Baker 1999). Although we could not prove 100% our final diagnosis but the negative results of the complex examinations focusing on the frequent causes of the headshaking turned us towards the pathological conformity of the incisors including the supernumerary one.

A 2-year-old Thoroughbred filly presented for a facial deformity that occurred from a traumatic injury as a foal. A Computed Tomography examination revealed that the coronoid process of the right vertical ramus (mandible) fused with the zygomatic arch creating a pseudoankylosis. The boney callus limited the horse’s mobility of the jaw and her ability to prehend food, graze and masticate. Additionally, a severe skull asymmetry was present which created a “shearing” malocclusion involving the left maxillary and mandibular 2nd and 3rd deciduous premolars.
The horse was placed under general anesthesia. An initial vertical incision was created over the zygomatic arch in alignment with median aspect of the long axis of the coronoid process. Once the zygomatic arch was isolated a sagittal saw was used to create a 2.5 cm segment of the arch directly over the coronoid process. A Hall’s surgical drill with an oval carbide bur was then used to create an osteotomy of the segment and section through the callus down to the coronoid. The segment and callus were removed to expose the coronoid process. Once isolated a 3.5 cm long section of the coronoid process was sectioned using the surgery drill with a long bur and guarded shank. Care was taken to leave a thin rim of bone along the medial aspect of the coronoid to avoid trauma to soft tissue, vascular and nerve structures. Using gentle pressure with an osteotome the final portion of the coronoid was severed.
An additional incision was created just dorsal to the coronoid process. A Periosteal elevator was used along the axial and lateral aspect of the sectioned coronoid process to remove soft tissue attachments so that the segment could be elevated and removed through the dorsal incision. Both incisions were closed and increased mobility of the jaw was noted.
A dental speculum was placed. The left maxillary and mandibular deciduous 2nd and 3rd premolars (606, 607, 706 and 707) were extracted due to severe malocclusion. Slight odontoplasty was performed on the left maxillary and mandibular deciduous 4th premolars and permanent 1st molars (608, 708, 209 and 309).

A one-month follow-up surgical and oral examination was performed. Both surgery sites had healed. The range of jaw motion improved, and the dental speculum could be opened an additional ~20 mm. The left maxillary and mandibular permanent 2nd and 3rd premolars were partially erupting.

Introduction
In recent years, it has become increasingly recognized that many cases of equine sinus disease are accompanied by nasal cavity disorders. Together, they can be more accurately referred to as sinonasal disorders.
Nasal conchal bulla disorders
Sinus-associated nasal disorders include empyema or distortion of the ventral and dorsal nasal conchal bullae. These anatomical structures have often been neglected in the equine literature. Nasal conchal bulla changes are observed in more than 50% of horses with sinus disease, particularly in cases with purulent sinusitis, such as primary and dental sinusitis.
Whilst computed tomography imaging (CT) is the most reliable method for detecting such changes, financial and practical limitations often restrict its use. These conchal bulla changes can usually be endoscopically identified in the lateral aspect of the middle meatus as a swollen, rounded structure, possibly fistulated. A smaller (typically less than 10 mm diameter) flexible endoscope is best for this examination. With appropriate training, nasal conchal bulla changes can also be recognized on lateral-oblique head radiographs. Anatomical, endoscopic, and diagnostic imaging examples of normal and diseased nasal conchal bullae will be presented, and their treatment discussed.

Sinonasal fistulation
Another common concurrent sinus and nasal disorder is spontaneous sino-nasal fistulation, which mainly occurs between the lateral aspect of the middle meatus and the rostral or rostro-medial aspects of the ventral conchal sinus. When identified, this fistula can sometimes be used as a portal to lavage the sinuses. However, direct endoscopic access to the rostral maxillary sinus from this portal may be difficult in young horses.

Inspissated Exudate and Sequestra in the Middle Meatus
In many cases of sinusitis (44% in a recent large study), the middle meatus, particularly its lateral aspect, develops an accumulation of inspissated exudate, and/or sequestered nasal conchal or nasal bulla bone, sometimes with overlying secondary, dark fungal plaques. These lesions are best detected using a small endoscope as described above, which can actually be more sensitive than CT imaging in identifying these lesions.
In some cases, visualization of the middle meatus may be obstructed by large amounts of exudate present at this site. Vigorous flushing of this area transendoscopically, using high volumes of lukewarm water or 1% saline solution using a diastema pump, can remove exudate and allow clearer visualization of the remaining area. Most such exudate can be lavaged into the nasopharynx or common nasal passages, as described earlier. Firmer areas of inspissated exudate can be “flicked” down into the nasal passages by flexing the endoscope tip, where they may be swallowed or snorted out of the nostrils. Irregular pieces of the thin, lacelike bone can be transendoscopically grasped with biopsy forceps and retracted back through the middle meatus and then nostrils or pushed into the common nasal meatus if too large. Examples of these middle meatus lesions will be presented.

Triadan 06 and 07 Infections and Sinus Disease
Because their apices normally lie outside the sinuses, apical infections of Triadan 06 and Triadan 07 cheek teeth do not directly cause equine sinus disease. However, infections of these teeth may be present along with apical infections of adjacent Triadan 07 and 08 teeth, particularly of the 08, and so be associated with sinusitis. There are also documented instances where apical infection of the Triadan 07 teeth led directly to sinusitis, and some examples will be presented

Sino-Nasal Fistulation and Sinus Disease
The formation of an oro-nasal fistula following the extraction of Triadan 06 or Triadan 07 teeth allows food material to enter the nasal cavity. This will lead to foreign body rhinitis, which can become severe in some horses and can subsequently result in ipsilateral sinusitis.