Orthodontic appliance in a dog
(31.01.2008) “Spirit” is 10 months old Cocker Spaniel, male, not castrated with an extreme class I malocclusion with a category 4 linguoversion of the canines or base-narrow canines.
Fig. 1
In Fig. 1 we can see the extreme severity of the condition and the crater caused by the misaligned caninus on the left side (pointed with the black arrow).
This crater was actually 5 mm deep and had an embedded small stone in it. After removal of the stone we could assess the degree of local injury.
The palatal bone was curetted and the necrotic material removed. The bleeding was moderate and local antiseptic (poviodine) was applied Fig.2.
We constructed from surgical 0,6 mm wire 2 U shaped loops between the 3rd incisor and canine tooth.
After etching with 37 % orthophosphoric acid we could than rinse with water and than dry the respective teeth in order to prepare them for the application of the acrylic material Fig. 3. After application of self curing acrylic material (ProTemp Garant) we proceeded in intimately shaping the deflecting grooves, Fig. 4.
Fig. 2
There are two basic types of orthodontic appliances: removable and fixed. Although both types can be used in most cases, there are certain circumstances in which each is the appliance type of choice.
It is necessary to assess and consider treatment of all other oral and dental problems when orthodontics is being considered.
Erosions, cavities, and other dental and oral diseases generally need to be treated or controlled before the placement of an appliance. However, when occlusal problems are initiating periodontal disease, orthodontics may be instituted to help in its treatment.
Removable appliances are those designed to be easily and routinely removed and then reinserted.
These appliances are preferred in cases in which intensive oral hygiene is required due to oral or dental disease or other dental treatments must be carried on simultaneously.
This permits the removal of all food debris, brushing of the teeth, treatment of periodontal infections, cleaning of the appliance, and treatment of other dental problems as necessary.
Fig. 3
In addition, repairs can be made at leisure or by a technician while the device is removed. In veterinary orthodontics, most of these appliances consist of three parts: a removal base, an active force attached to the base, and a fixed anchorage.
The base of the appliance, which may be made of acrylic or metal, serves as a platform for the active force. The active force is usually provided by screws, springs, or elastics.
The anchorage most often consists of brackets bonded to teeth that allow elastics to attach the base in place for activation.
The main disadvantages are that the appliances are frequently bulky, sometimes interfering with normal occlusion, and some astute pets may learn to remove the appliance themselves, presenting the possibility that the appliance may then be swallowed and become an intestinal foreign body.
Fig. 4
Fixed appliances are typically attached to provide a center for movement force without removal until the tooth attains its target site.
Fixed appliances customarily provide greater security of the applied force; they are also less bulky than removable appliances and have improved precision and enhanced gentleness, when properly applied and supervised.
The main disadvantage of this type of appliance is the need for greater hygiene care, as food and debris may accumulate beneath its recesses and visual monitoring for disease or trauma may be hampered by the appliance.
Additionally, any repairs must generally be made chair side with a sedated patient. Fixed appliances ordinarily consist of three parts: base plates or bands for anchorage, a framework or bracket for force attachment, and the active force. The active force may consist of wires, springs, screws, or elastics.
Fig. 5
Materials used for fabricating orthodontic devices, orthodontic wire is commonly used in a large variety of orthodontic appliances.
There are three basic types of orthodontic wire: round, rectangular, and braided. Round wire is the simplest to handle and work with, but when torque is required, specially designed auxiliary parts must be added to achieve a torquing force.
Rectangular wire, when used with rectangular brackets or tubes, can apply torquing forces with the greatest accuracy.
Braided wires are made of multiple strands of thinner wires that are twisted or braided together; they provide the most flexibility of the three types.
The physical properties and mechanical behavior of wire depends to a great extent on the types of metal employed within them. Stainless steel is the most commonly used metal, but many other types and combinations are utilized.
Nickel-titanium memory-type wire is becoming a more common orthodontic material. ADA Specification No.32 defines all orthodontic wire requirements except those containing precious metals.
Fig. 6
Springs, kick and coil can easily be incorporated into appliances to provide either traction or compression. Open coil springs are used for compression, and closed coil springs for traction.
There are many types of kick springs, but the more common are the finger, cantilever, T,W, and Z springs. With fixed appliances, springs can provide bodily movements, but they are normally used for tipping.
The longer the wire and the more helical loops applied to the spring, the gentler will be the force and the better the maintenance.
We performed weekly controls and biweekly adjustments by adding more material and reshaping the guidance grooves. 6 weeks later we considered that the canine teeth have reached a normal position in relation with the opposing maxillary canines and removed the device Fig 5 and Fig 6.
DDr. Camil Stoian, PhD, Dipl. EVDC
