Oral Ranula

Introduction

The term ranula is derived mainly from the Latin word rana, meaning literally like a little frog. This terminology is explainable by the resemblance of the ranula to the underbelly that bulges out in frogs. The ranula's origin or occurrence is nearly always sublingual or on the floor of the mouth. To differentially help the dental surgeon diagnose these simple lesions as ranulas, it is pivotal for the dental surgeon to know the occurrence of the different lesions associated with salivary glands. The parotid salivary gland remains a common site for developing both benign and malignant tumors (for example, pleomorphic adenomas are initially benign but can potentially become malignant if left untreated). In addition, the submandibular gland remains a common site for forming sialoliths or sialolithiasis (salivary gland stones).

What Is an Oral Ranula?

Oral ranulas may be defined as extravasation mucocele of the sublingual salivary gland that occurs particularly or specifically in association with the sublingual and submaxillary ducts in the floor of the mouth. Less often, it arises from the ducts of the maxillary salivary glands.

Is Oral Ranula Serious?

Ranulas are not serious. They are the most common salivary gland infections caused by trauma. Ranulas typically affects children and young adults, with the highest incidence in the second decade. Mucus retention cysts are more common in older people, with a peak incidence in those between the ages of 50 and 60. They are not contagious, as bacteria, fungi, or viruses do not cause them.

How Is Oral Ranula Classified?

Mainly, oral ranula can be classified into:

• Simple Ranula: In simple ranulas, the extravasation is caused by a leak in the saliva by the discrete lobular units of the salivary glands into the surrounding tissue spaces. However, simple ranulas are limited to the floor of the mouth beneath the tongue.

• Plunging Ranula - When a simple ranula erodes or herniates through the mylohyoid muscle, causing dehiscence, it is known as the plunging ranula. Both simple or plunging ranulas are not uncommon mucoceles, and the main attribution or causative factor in plunging ranulas is the occurrence in the floor of the mouth due to the dehiscence of the mylohyoid muscle.

What Are the Clinical Features of Oral Ranula?

Ranulas may simply be observed clinically by the surgeon as clear or bluish bubble-like growth in the floor of the mouth.

1. Initial Ranulas: They do not present with pain but may increase in size. It may cause problems for the patient with oral discomfort and increasing pain in the affected area both during speaking and swallowing.

2. Large Plunging Ranulas: They can cause breathing issues because they can plunge or press into the trachea or the windpipe region.

3. Plunging Ranulas: They can present as masses in the neck without a bubble-like lesion on the floor of the mouth.

What Is the Pathogenesis of Oral Ranula?

If a ranula is considered to be of a congenital origin, it occurs following a perforation or stenosis of the salivary gland ducts leading to cyst formation. The main pathogenesis is always linked to trauma to the sublingual gland duct, which leads to the extravasation of mucous into the submucous spaces of the gland via hydrostatic pressure. A pseudocyst gets formed by this mucus escape reaction (MER) within the gland space. Trauma directly damages the acini of the salivary gland with imminent ductal obstruction. These instructions create a back-pressure of secretion that builds up with subsequent rupture of the acini. These three phenomena of hydrostatic pressure, extravasation of mucus, and then pseudocyst formation are attributed to the occurrence of a ranula. The other factors implicated in formation are:

• A congenital narrowing of the duct.

• Dehiscence of the mylohyoid muscle.

• Sialolithiasis or sialolith formation.

Whereas in cases of simple or superficial mucoceles, trauma does not always appear to play an important role in the pathogenesis as per traditional research. In these cases, it would be simple mucosal inflammation that involves the minor gland duct, resulting in the delegation, blockage, and eventual rupture of the duct with the spilling of the extravasation fluid. Changes in minor salivary gland function and composition of the saliva can also be responsible for ranular development. Few hypotheses suggest an immunological reaction associated with increased levels of matrix metalloproteinase, tumor necrosis factor-α, type IV collagenase, and plasminogen activators. These factors could enhance the accumulation of proteolytic enzymes observed for the invasive character of extravasated mucus in the ranulas.

What Is the Diagnosis and Surgical Management of Oral Ranula?

The following features can be observed in the glandular secretions or extravasated mucus if these lesions are diagnostically analyzed by cytochemical evaluation. They are:

• High mucus content.

• Inflammatory cells.

• Elevated levels of amylase and protein.

Management of ranula depends on the following multiple modalities, which the dental or maxillofacial surgeon considers.

• The size.

• The extent of the lesion.

• The exact location.

1. Simple Aspiration: Techniques ranging from simple aspiration to complete excision of the ranula are indicated only for small lesions that are minimally invasive. As ranulas can be considered pseudocysts, a simple aspiration or incision to drain the swelling can potentially result in the recurrence of the lesion, and the treatment effect remains temporary if any underlying penetration or herniation has occurred. This is true of most invasive ranulas, given that removing the pseudocyst alone may not resolve the issue given its recurrence and the extravasation issue that may persist within the salivary gland.

2. Marsupialization: Other mainline modalities include marsupialization, where the dental surgeon performs a slit within the cyst, and suturing of the edges of the lesion is done post the procedure that allows the cystic contents to drain freely.

3. Complete Excision: Complete excision of the ranula involving the salivary glands is invasive, and in these cases, the damaged sublingual or submandibular salivary gland may be excised. This remains an invasive surgical modality reserved for particularly large ranulas.

Other modern advances in dentistry have been proposed and practiced in recent decades to decrease the invasiveness of surgical procedures to excise large ranula lesions. Laos has the added advantage of minimizing injury to adjacent structures. Alternately, dental surgeons use these procedures for surgical procedures and minimal shrinkage or excision of ranulas. They are:

• Cryotherapy.

• Hydro dissection.

• Laser ablation.

• Sclerotherapy.

Conclusion:

Oral ranulas are simple extravasation salivary mucoceles that may turn invasive if left untreated. Prompt management by the dental surgeon can prevent oral discomfort and pain in the patient.