What Is the Origin of a Dental Cyst?
A dental cyst is basically an epithelial-lined cavity. While the epithelial lining of these dental odontogenic cysts arises from the odontogenic epithelium, these cysts may also include reduced enamel epithelium (REE), the epithelial cell rests of Serres, and the epithelial cell rests of Malassez (ERM).
The reduced enamel epithelium is the epithelium that surrounds the developing crown of the tooth. The rests of the Serres are remnants of the degenerated dental lamina that is responsible for initiating tooth formation during the sixth week of embryonic life. The ERM or the epithelial cell rests of Malassez are the residual cells resulting from a disintegration of Hertwig's epithelial root sheath that initiates tooth root formation. Ultimately, all these rests, when they undergo entrapment within the maxillary and mandibular gingiva and the alveolar bone, result in the formation of these epithelialized cavities.
What Are Eruption Cysts?
Eruption cysts are developmental cysts in origin that mainly occur due to the buildup of blood or fluid within the dental follicular space that is expanded. The expanded space develops because of the separation of dental follicles from the enamel of the erupting tooth. Eruption cysts are located on the crown of a tooth at the eruption stage at a superficial level. The cysts may most often project out as an elevated bluish and translucent lesion that is easily compressible. They can project in the shape of a dome in the alveolar ridge as a sequence of eruptions. Oral discomfort though rare in the infant or child, however, can definitely hinder or harm the appearance of teeth in the oral cavity due to the observable or visible projection.
Though many hypotheses exist as to the origin of ECs, the multifarious causes are due to early caries, trauma, or infection. But lack of space for deciduous or permanent tooth eruption and genetic predisposition have also been considered as other causes. Research suggests that the exact etiology behind the development of an EC is unclear. A 1.4:1 male-to-female ratio for EC is prevalent globally. EC usually presents either in the first or second decades of life (with the average of this cyst occurring in children around seven years of age). This change impacts the deciduous mandibular central incisors or permanent first molars predominantly. On radiographic examination, it may be difficult to distinguish the space between these cysts and the tooth, but in clinical examination by the dentist, it can be observed clearly.
Researchers also attribute the origin to degenerative changes of the reduced enamel epithelium after amelogenesis. Another clear hypothesis exists to show that the cyst, in fact, develops from the remnants of the dental lamina that layers the tooth that is to erupt. Regardless of this unclear etiology, the term EC is correctly used when the affected tooth is located only in the soft tissues. If the tooth is surrounded by bony projection or bone, then it is considered a dentigerous cyst, according to the classification adopted by the World Health Organization.
What Are the Clinical Features of Eruption Cysts?
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The overlying gingival tissue for an eruption cyst has edema, a bluish hue, or a translucent appearance that is clinically confirmative.
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Clinically, the EC usually appears as a circumscribed, floating lesion. Its translucent appearance is due to its volumetric increase at the site of tooth eruption.
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When the cystic cavity contains blood, then the swelling may turn purplish or dark blue color and is then referred to as an "eruption hematoma."
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Eruption cysts are diagnosed clinically; however, they should also be confirmed with radiographic imaging.
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The dental surgeon then needs to determine the source of delayed eruption, whether it is associated with a deciduous or permanent tooth.
What Is the Differential Diagnosis of Eruption Cyst?
The differential diagnosis to be adopted by the dentist for differentiating EC is from other developmental odontogenic cysts that are classified as:
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Gingival cyst.
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Odontogenic keratocyst (OKC).
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Orthokeratinized odontogenic cyst.
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Glandular odontogenic cyst.
How to Manage Eruption Cyst?
Eruption cysts are definitely self-limiting and do not usually require treatment until they are a source of discomfort either to the infant or to the mother while breastfeeding. These cysts typically rupture on their own as the tooth erupts. If clinically symptomatic, the cyst should be deroofed by the dentist or pedodontist to reduce its inflammatory pressure. If initial treatment is not required, as advised by the dentist, then close monitoring of the lesion should be done to allow spontaneous regression unless infectious symptoms start to occur. The possibility of surgical intervention is when there is a lack of spontaneous regression.
The treatment plan should be explained to the child's parents, and their written consent is to be obtained prior to treatment. Follow-up examinations can be performed at 15-day intervals post-surgical removal of the cyst. However, in most cases, the EC subsides spontaneously; therefore, the main treatment is close monitoring with follow-up throughout the eruptive process of the area involved or site of eruption.
When Should the Surgical Approach Be Considered?
Generally, the surgical approach involves a simple excision of the cyst and then exposure of the crown to erupt. Apart from follow-up and monitoring of the infant at 15-day intervals, oral hygiene instructions should be given to parents to execute it for their child. The treatment for drug-related ECs may be more complicated as it involves periodontal healing for which scaling, root planing, and flap designs may be necessitated.
When the eruption cysts prevent the eruption of a deciduous tooth, a marsupialization procedure can be considered by the surgeon. Extraction is only indicated when the teeth present with mobility or interfere with breastfeeding or lactation. Also, in rare cases when the natal or neonatal tooth is dangerous to the newborns, for example, if it is very mobile or loose, then during breastfeeding, it can get aspirated. Hence extraction is indicated.
It is essential for the dental surgeon to discuss clinical and radiographic findings with patients and offer these multiple treatment options. Parents of the infant can also understand the need for surgical procedures as the last option, especially if the child is unresponsive to the initial treatment.
Conclusion
The pediatric dental approach to the oral cavity, be it of the deciduous or permanent tooth eruption, requires pedodontists to be aware of the characteristics of eruption patterns for primary and permanent teeth; hence they have to handle and diagnose these cysts in the early stages. Eruption cysts, however, have a good prognosis and are commonly self-limiting, as the erupting tooth will rupture the cyst more often.
