Dilacerated Mandibular First Molar in Dogs

The abnormal development and formation of the mandibular tooth, a molar located three teeth away from the midline of the jaw, is an oral health issue seen primarily in small breed dogs. The mandibular tooth is one of the first permanent teeth to develop a calcified crown, and one of the largest.

There is no gender or particular breed predilection, but small breed dogs are at risk due to the small amount of space in the jaw for the molar to grow into. Therefore, it is generally recommended that small breed dogs be given a full evaluation of the mandibular first molars as they are growing in. 

Symptoms and Types

The defect will appear at the neck of the madibular tooth, often with gum evidence that the gum is receding. There may even be extensive bone loss near the root and possible exposure of pulp inside of the tooh. X-rays may reveal discontinuity between the roots and crown and/or presence of pulpal stones in the canal or chamber of the tooth.

Causes

One of the possible causes for this developmental problem is a mechanical challenge (lack of space) in the mouths of small dogs that impede proper crown-root development. Invagination, a folding in of the enamel and/or cement of the tooth, sometimes occurs at the neck of the tooth, often with some degree of gingival recession (receding of gums) at the site.

Diagnosis

Your veterinarian will perform a thorough physical and oral exam on your dog, taking into account the background history of symptoms, if there have been any. Dens-in-dente, an anomaly of development resulting from the deepening of enamel into the dental papilla (the cells involved in the developing tooth), typically begins at the crown and often extends to the root before the calcification of the dental tissues takes place. Traumatic damage to the tooth, possibly from aggressive deciduous tooth (i.e., baby tooth) extraction, may be linked to a loss of dental integrity.

If your veterinarian finds that the tooth is too damaged to remain, an assessment of the remaining mandibular bone will be an important prior to an extraction attempt. The diagnostic evaluation will include taking a dental X-ray to evaluate the extent of the changes, particularly at the roots.