VN October 2020

Vetnews | October 2020 29 Ankylosed teeth are a particularly difficult entity to deal with and especially so if no radiographs are available of the tooth or teeth in question (Figure 1). This is a condition we frequently see with tooth resorption (TR) which is common in cats. Saying it is common in cats does not exclude dogs. In fact, one study reported close to 54% of the dogs in their study to have TR 1 . In broad terms with TR parts of the periodontal ligament is destroyed and the osteoclasts present may also destroy cementum and dentin. Alveolar bone often then grows into these spaces fusing with the exposed cementum and/or dentin. Tooth extraction is based on destroying the ligamentous attachment of the tooth to its surrounding alveolar bone. With TR and ankylosis, this ligament is not available anymore and it will be impossible to separate the tooth from the surrounding ankylosed alveolar bone. It is these cases that causes immense frustration as the clinician is not able to visualise the root and alveolar bone in order to separate them. Very often this leads to excessive bone formation as you try to remove tissue where you think the root should be. This approach is both unrewarding and detrimental to the patient. In 1995, Greg du Pont 2 published the saving grace for many of us. He showed that, after radiographing affected teeth and declaring them free of periodontic or endodontic infections, he amputated the crowns by elevating an envelope flap in the gingiva. After amputation he sutured the envelope flap closed and followed them for a period of 5 – 36 months radiographically. In one cat that later developed stomatitis they had to remove the remaining tooth bits; all the other cats healed with most of them showing complete resorption of the roots. This has really been a game changer for us in veterinary dentistry and I am sure many a cat (and dog) is better off for it. Having sung its praises you need to remember that this is not a blanket permit to just amputate crowns for every patient. It remains your duty to make sure the tooth is free from infection before you can consider this treatment. If there is any doubt of if the crown amputation was the correct treatment, follow-up radiographs are indicated (Fig. 2). v References: 1. Peralta S, Verstraete FJM, Kass, PH. 2010. Radiographic evaluation of the types of tooth resorption in dogs. American Journal of Veterinary Research 71(7):784-93. 2. DuPont G. 1995. Crown amputation with intentional root retention for advanced feline resorptive lesions – a clinical study. Journal of Veterinary Dentistry 12(1):9-13. Regulars I Dental Column Figure 1. The radiograph of this cat’s mandible shows TR affecting the mandibular canine tooth, 4 th premolar and molar tooth. The 3 rd premolar tooth has completely been destroyed by TR and replaced with alveolar bone. There is little evidence of periodontal ligament at any of the teeth/ roots visible in this radiograph. Figure 2. A follow-up radiograph of a dog that had several crown amputations of its mandibular teeth. No periodontal or endodontal disease is present. S A V A B R A N C H C O N G R E S S 2 0 2 0 Eastern Free State Golden Gate Hotel | SANParks | Clarens 03 October 2020 ‘20 www.bit.ly/EFS_2020