Case of the Month

An intriguing dental scan and how to interpret it

OPT requested for dental evaluation in a 70 years-old male patient with previous treatment history. General evaluation and specific control on bone morphology, edentulous areas, for future implantological evaluation. Patient reports pain in the right lower jaw.

Radiology Report

The thickness of the cortical bone appears within physiological parameters. The condyles are of normal radiomorphology.

There is a cystiform finding in the fourth quadrant which includes the mesial apex of 47. This cystiform finding is approximately 39.5 * 18.3 mm in size. Clinical co-evaluation and biopsy examination are recommended. Signs of periodontal disease affecting the elements present.

Radio-transparent periapical lesion of 43.

To learn more – Dental cysts

What are they?

Dental cysts (odontogenic cysts) are closed cavities that form inside the bones of the jaw (more frequent) and maxilla (less frequent). They are well-circumscribed cavities contained by a lining epithelium, a mucous membrane that precisely encloses the cyst and separates it from the remaining bone tissue within which it was formed. Inside the cavity there is always serous or mucous material, or even, although rarely, gaseous.

We can distinguish three main categories of cysts:

  • Root cysts: they are cysts that originate from the roots of teeth that undergo chronic inflammatory processes.
  • Follicular cysts: they develop from some epithelial cells of the developing dental germs. They often include a whole tooth inside.
  • Periodental cysts: they generally develop between the premolars of the mandible.

How to distinguish them

It is also important to distinguish between dental cysts and

  • Pseudo-cyst: cavity of different origin, characterized by not being lined with epithelium. They are usually aspects of intra-osseous tumor proliferations.
  • Dental abscesses: pus-filled cavities commonly originated from necrosis of the dental pulp due to destructive caries or from infected periodontal pockets in periodontal diseases (pyorrhea).
  • Radicular granuloma: chronic infection of limited size, usually affecting a tooth root, always caused by necrosis of the tooth pulp. It appears as a solid, well-organized structure of inflammatory tissue.

How do they form?

The causes of cyst formation can be multiple:

  • Presence of impacted dental germs or actual impacted teeth. The cyst is present from birth or is related to development.
  • Late complication of dental procedures such as extractions or root canals.
  • Complications of dental granulomas.
  • Trauma

How do you know you have them: are there any symptoms?

Small dental cysts are usually asymptomatic and are discovered by chance, during dental radiographic investigations performed for other reasons.

If large, however, they can produce swelling and swelling phenomena, pain of varying intensity, mobility of the dental elements. In some cases, they can even cause a fracture of the jaw.

The correct diagnostic approach involves:

  • A biopsy exam to avoid the possibility that it may be a tumor pseudo-cyst.
  • The 3D tomographic examination (CBCT) allows to define the size, shape and relationships with the neighboring teeth and with the mandibular nerve (for mandibular cysts) and the maxillary sinuses and nasal cavities in general (for maxillary cysts).

Surgery to cure the dental cyst

The actual therapeutic treatment is commonly surgical. The size and relationship with the adjacent teeth determine the degree of invasiveness of the intervention:

  • Apicoectomy: when the cyst is small and attached to the root of a tooth, a minimally invasive operation can be carried out which involves the removal of the cyst and the apical portion of the root root involved.
  • Cystectomy: when the cyst is larger in size, it is necessary to proceed with delicate surgical interventions which will have to lead to the complete enucleation of the cyst. Often one is forced to sacrifice the teeth placed on top due to the impossibility of reaching the cyst.

Following the removal of an odontogenic cyst it is important to follow periodic checks to avoid and prevent recurrence.