FORL
FORL ( Feline Odontoclastic Resorptive Lesions ) are a common and very painful disease of the teeth in cats . It is characterized by decalcification of the tooth substance, especially in the area of the tooth neck, by the body's own cells, the odontoclasts . Outdated names for this disease are neck lesions and cat caries .
The disease occurs in 25–30% ( prevalence ) of domestic cats , in cats over five years of age every second is affected.
Etiology and pathogenesis
The cause ( etiology ) of FORL has still not been finally clarified. Recent studies assume that it is a disruption of the calcium balance in the body. The disease occurs more frequently with reduced calcium intake or a low calcium / phosphorus ratio in the diet. This triggers an increased formation of activated vitamin D 3 (1,25-dihydroxycholecalciferol), which leads to a mobilization of calcium and phosphorus from the hard substances. Also hormonal disorders (eg. As the hormonal changes after castration with osteoporosis ) may be involved. According to Zetner, inflammation of the gums and the gums are the main causes. Why this mineral release takes place primarily from the hard substances of the teeth and less from the bones is unclear.
Odontoclasts (dentinoclasts) are activated by cytokines ( interleukin-1 α and β, interleukin-3 , interleukin-6 , tumor necrosis factor ) . These usually begin with the breakdown of the dentin in the neck area at the transition from the enamel to the cement . This leads to an increasing hollowing out of the tooth. By destroying the tooth- supporting apparatus , the shock-breaking protective effect of this structure is canceled.
However, there is no bacterial involvement and the adjacent dentin areas are also unchanged, which is why the term “cat caries ” is inappropriate.
to form
A distinction is currently made between three types of feline odontoclastic resorptive lesions. In all cases the tooth pulp ("tooth pulp ") with its nerve fibers is still vital, which is why these processes are very painful. This often results in reduced food consumption ( anorexia ), head shaking, head tilt ( torticollis ), grinding of the teeth and excessive tongue movements. Increased salivation ( hypersalivation ) can also occur. Sometimes dry food is preferred over wet food, as the former can be swallowed whole quickly and is less chemically irritating to the lesions. The changes are often symmetrical. The third premolar and the first molar of the lower jaw as well as the fourth premolar of the upper jaw are particularly often affected.
FORL type 1
FORL type 1 usually develops together with inflammation of the oral cavity mucous membrane ( stomatitis ) and the gums ( periodontitis ), often combined with plaque and tartar . In this type, in addition to changes in the teeth, there are also degradation processes in the tooth sockets . The area of the tooth crown is usually not affected, the gingival furrow ( sulcus gingivalis ) and the periodontal gap remain apical (towards the tooth root) of the lesion.
The gums are reddened, oedematized and there may be growths ( hyperplasia ) of the gums. The actual lesions on the tooth neck are therefore usually not visible. The diagnosis can be made by probing the gum line and taking an x-ray . The latter shows bone loss in the tooth and tooth root.
FORL type 2
FORL type 2 lesions initially develop without inflammatory involvement, although periodontitis can develop in the further course. The tooth loss takes place without a reconstruction of the tooth socket . The gum groove is lost through remodeling processes and adhesions. In contrast to type 1, there are usually also repair processes with deposition of replacement tissue.
With this form, the teeth appear clinically healthy at first and only small, localized inflammation of the gums is visible. The processes only become visible when the tooth is further hollowed out and the tooth crown has broken out. The x-ray examination shows the bone loss in the tooth and tooth root. The gum groove cannot be probed.
FORL type 3
In FORL type 3, type 1 and type 2 lesions occur simultaneously on one tooth.
Diagnosis and differential diagnosis
The diagnosis can be made based on the clinical picture, probing, and an X-ray examination . When probing with a sharp probe , cats show the typical chattering of teeth that indicates a toothache. It should be noted that a 40% difference in density between normal tooth tissue and lesion is necessary for radiological detection, so early stages can be overlooked.
In the differential diagnosis, feline gingivostomatitis in particular must be clarified, in which there is also severe inflammation of the gums, but no degradation processes in the tooth substance. However, both diseases can occur at the same time.
therapy
Conservative treatments with the application of fluorine varnish and dental fillings are no longer recommended today. The only sensible therapy is the extraction of affected teeth. This leads to the loss of the affected teeth, but removes the painful cause. The extraction is accompanied by the administration of painkillers and mostly antibiotics .
With FORL type 1, a complete removal of all tooth parts must be ensured, no remnants of the tooth roots may remain in the tooth socket, as they can maintain the inflammation. If necessary, the extraction must be performed surgically. Treatment of periodontal disease must then be carried out. With FORL type 2, complete extraction is mostly impossible due to the adhesions. As a rule, only the affected tooth crown is removed ("crown amputation") and the root is left in the tooth socket. Then the wound is covered with a gum flap. The prerequisite is that the tooth root already shows degradation processes, because these contribute to a complete resorption of the root after covering .
If feeding errors can be determined, a change in feed or the addition of calcium is of course indicated. Any osteoporosis must also be treated in order to prevent further progression of the processes.
literature
- Martin Florian Buck: Dental resorptions in cats . In: veterinärspiegel . No. 1 , 2016, ISSN 0940-8711 , p. 3-8 .
- M. Eickhoff: FORL. Occur frequently - are diagnosed far less often. Small animal in detail 4/2003, pp. 11–15.
- Karl Zetner: FORL (feline odontoclastic resorptive lesion, neck lesion) . In: Marian C. Horzinek et al. (Ed.): Diseases of the cat . Enke Verlag, 4th edition 2005, pp. 319-320, ISBN 3-8304-1049-2
Individual evidence
- ↑ a b Karl Zetner: FORL (feline odontoclastic resorptive lesion, neck lesion) . In: Marian C. Horzinek et al. (Ed.): Diseases of the cat . Enke Verlag, 4th edition 2005, pp. 319-320, ISBN 3-8304-1049-2
- ^ A b Martin Florian Buck: Tooth resorptions in cats . In: veterinärspiegel . No. 1 , 2016, ISSN 0940-8711 , p. 3-8 .
- ↑ M. Eickhoff: FORL. Occur frequently - are diagnosed far less often. Small animal in detail 4/2003, pp. 11–15.
