Dens evaginatus is a rare odontogenic developmental anomaly that is found in teeth where the outer surface appears to form an extra bump or cusp.
Dens evaginatus | |
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Other names | Tuberculated cusp, accessory tubercle, occlusal tuberculated premolar, Leong's premolar, evaginatus odontoma, occlusal pearl[1][2] |
Specialty | Dentistry |
Premolars are more likely to be affected than any other tooth.[3] It could occur unilaterally or bilaterally. [1] Dens evaginatus (DE) typically occurs bilaterally and symmetrically.[4] This may be seen more frequently in Asians[3] (including Chinese, Malay, Thai, Japanese, Filipino and Indian populations).[4]
The prevalence of DE ranges from 0.06% to 7.7% depending on the race.[3] It is more common in men than in women,[3] more frequent in the mandibular teeth than the maxillary teeth.[1] Patients with Ellis-van Creveld syndrome, incontinentia pigmenti achromians, Mohr syndrome, Rubinstein-Taybi syndrome and Sturge Weber syndrome are at a higher risk of having DE.[3][2]
It is important to diagnose DE early and provide appropriate treatment to help prevent periodontal disease, caries, pulpal complications[3] and malocclusion.[2] It occurs on the cingulum/occlusal surface of the teeth. The extra cusp can cause occlusal interference, displace of the affected tooth and/or opposing teeth, irritates the tongue when speaking and eating and decay the developmental grooves. [2] Temporomandibular joint pain could be experienced secondarily due to occlusal trauma caused by the tubercle.[1][2]
This cusp could be worn away or fractured easily.[1][4][2] In 70%[4] of the cases, the fine pulpal extension were exposed which can lead to infection,[4] pulpal necrosis and periapical pathosis.
The cause of DE is still unclear.[2] There is literature indicating that DE is an isolated anomaly. During the bell stage of tooth formation, DE may occur as a result of an unusual growth and folding of the inner enamel epithelium and ectomesenchymal cells of dental papilla into the stellate reticulum of the enamel organ.[5] [4]
Diagnosis of DE can be difficult when there is no signs and symptoms of necrotic or infected pulp.[1] It is a challenging task to differentiate between a true periapical lesion and a normal periapical radiolucency of a dental follicle of an immature apex.[1]
The anterior DE tubercles have an average width of 3.5mm and length of 6.0mm,[4] while posterior tubercles have an average 2.0mm in width and length of up to 3.5mm.[4] If the cusp of Carabelli is present, the tooth associated are often larger mesiodistally and it is not uncommon that a DE involved tooth has an abnormal root pattern.[4]
There are 4 different ways to classify/ categorize DE involved teeth.
If the tooth involved is asymptomatic or small, no treatment is needed [3] and a preventative approach should be taken.
Preventative measures[3] include:
For teeth with normal pulp and mature apex, reduce the opposing occluding tooth.[4] Reinforce the tubercle by applying flowable composite.[4][2] Occlusion, restoration, pulp and periapex assessment should be done yearly.[4] When there is adequate pulp recession, tubercle can be removed and tooth can be restored.[4]
For teeth with normal pulp and immature apex, reduce the opposing occluding tooth.[4] Apply flowable composite to the tubercle.[4] Occlusion, restoration, pulp and periapex assessment should be done every 3–4 months until the apex matures.[4] When there are signs of adequate pulp recession, tubercle can be removed and tooth can be restored.[4]
For teeth with inflamed pulp and mature apex, conventional root canal treatment could be carried out and restored accordingly.[4]
For teeth with inflamed pulp and immature apex, shallow MTA pulpotomy could be performed and then restore with glass ionomer and composite.[4]
For teeth with necrotic pulp and mature apex, conventional root canal therapy could be done and restored.[4]
For teeth with necrotic pulp and immature apex, MTA root-end barrier could be carried out. Glass ionomer layer and composite could be used to restore the tooth.[4]
If there is occlusal interference, the opposing projection should be reduced.[3][2] Make sure that the tubercle does not contact other teeth in all excursive movement.[2] This is usually done over a few appointments, 6 to 8 weeks apart to allow the formation of reparative dentin to protect the pulp.[3] Fluoride varnish should be applied onto the ground surface.[7][6][3][4] Recall the patient for follow-up after 3, 6 and 12 months.[3]
In some cases, extraction[citation needed] could be considered (e.g. for orthodontic purposes, failed apexification)[2]