Keywords
parotid papillae - anatomical variation - anatomy
Introduction
The papillae, in general, are irregular interfaces between the epithelial tissues
and the lamina propria, with the form of conjunctival tissue evaginations. The parotid
gland is a salivary gland responsible for the secretion of saliva, a fluid that has
digestive, lubricating and protective functions. The parotid gland is the largest
of the three salivary glands. It is located between the branch of the mandible and
the structural process of the temporal bone. From its interior, a parotid duct enters
the buccal cavity through a small ostium at the height of the second maxillary molar
tooth.[1]
The parotid duct, also known as the “Stenseńs Duct,” is responsible for excreting
saliva from the parotid gland into the buccal mucosa of the oral cavity. This jugal
mucosa is the inner epithelial lining of the cheek, extending bilaterally from the
labial mucosa (inner portion of the labial) to the retromolar region. It is composed
of a smooth and rosy epithelium, with similar appearance to the labial mucosa.[2]
The saliva of the parotid gland is thrown in the parotid papilla region,[2] which is the terminal part of the duct. It has a triangular, elevated, papular and
pink configuration, located in the maxillary half of the jugal mucosa, more often,
adjacent to the first molar tooth.
Sialadenitis is an inflammatory disease that affects the salivary gland or its duct,
infectious or not, more common in the submandibular gland due to its unique duct and
greater contact with the salivary fluid - which is rich in minerals - and less frequent
in the parotid glands.[3]
In this context, the identification and dissemination of anatomical variations are
important, since they provide support for the interpretation of most varied diagnostic
or treatment situations that require invasive approaches by health professionals.[4]
Therefore, the objective was to report a case of anatomical variation of the parotid
papilla in a human corpse and its implication in sialadenitis, analyzing the morphometric
data of this variation as well as its clinical anatomic importance.
Materials and Methods
This case report was approved by the Ethics Committee of the Faculdades Integradas de Patos - PB, institution in which the work was developed, through statement n. 1,800,667
and CAEE (60421416.6.0000.5181).
The research was performed in the Morphological Sciences Laboratory of the Faculdades
Integradas de Patos - FIP, Paraíba – PB. The study object was a left hemiface of a
male adult human corpse (age unknown). An anatomical variation of the parotid papilla
was observed, with two papillae in the same hemiface. A morphometric analysis was
performed with the use of Stainless® digital caliper rule to verify the distance from
the variation to the most frequent location of the papilla.
Therefore, we search in the literature for possible implications of the parotid duct
on sialidenitis.
Case Report
A left corpse hemiface from the Anatomy laboratory of the Faculdades Integradas de
Patos - FIP was prepared for dissection. An anatomical variation of the parotid papilla
was found at the facial artery level, branch of the external carotid artery, with
two papillae in the same hemiface ([Fig. 1]).
Fig. 1 Left cadaveric hemiface, medial view. Normal parotid papilla (1) and variant (2)
in the retromolar space.
The parotid papilla is usually located at the neck level of the upper 2nd molar, expelling
the saliva produced by the parotid glands. The anatomical variation revealed a papilla
located posterior to the 3rd molar tooth, ∼18.8 mm away from the normal opening site
([Fig. 2]).
Fig. 2 Left cadaveric hemiface, medial view. Morphometric analysis of the parietal papilla
variation using a digital caliper rule.
When analyzing the hemiface it was verified that there could be two parotid ducts
or a branch of the duct with the two existing papillae. In humans, there is a papilla
for each hemiface, but this finding leads us to suggest that the appearance of a second
papilla would not alter the function of the parotid gland.
Discussion
Histologically, papillae are irregular interfaces between epithelial tissues and the
lamina propria, on the form of conjunctival evaginations. They occur more frequently
in coating epithelial tissues under the action of mechanical forces such as skin,
tongue and gums. The papillae increase the contact area of the dermis with the epidermis
reinforcing the union between these two layers. The papillae are more frequent in
areas subjected to pressure and friction.[1]
The parotid glands are located anteriorly and inferiorly to the auricle. The parotid
gland has a horseshoe shape that surrounds the two faces of the jaẃs posterior margin.
It occupies an osseoaponeurotic compartment, called the parotid cell or retromandibular
fossa. It is surrounded by a capsule of its own that gives off branches to the parenchyma
interior. It accompanies the external face of the masseter, next to the branches of
the facial nerve and the transverse artery, perforates the buccinator muscle and arises
in the buccal cavity in front of the 2nd upper molar tooth.[5] Sialadenitis is an inflammatory disease that affects the salivary glands due its
ducts partial or total obstruction. Sialolithiasis is characterized by the formation
of calcium calculi, which can appear in the salivary gland as well as in its respective
excretory canal, enhancing salivary ectasia and superinfection.[6]
In the study studies of Carta et al.[7] of the 48 patients studied, 68.75% had obstruction in the submandibular or parotid
ducts caused by obstruction by salivary calculi.
This pathology affects, more rarely the parotid gland, the submandibular gland (∼80–90%
of the cases),[8] while 5% -20% are found in the parotid gland, while the sublingual gland and the
minor salivary glands do not represent more than 2%, rarely due to anatomic ductal
abnormalities,[7] as it presents a single duct and gingival fluid (serum transudate) as a mineralizing
source for the subgingival calculi. The subgingival calculus is located below the
crest of the marginal gingiva and is therefore not visible on routine examination.[3]
Starting from the premise that the morphological characteristics of the ducts as well
as the location of the salivary gland papillae can contribute to the saliva stagnation,
which can lead to sialadenitis,[9] we believe that, in the anatomical variation found here, the variant parotid duct
located in the retromolar region and the subgingival mucosa may increase the chances
of the sialadenitis and/or sialolithiasis development in the gland or parotid duct
from the gingival fluid.
Conclusion
The variant parotid duct of rare localization, here identified and described in the
retromolar region (which is difficult to see). We believe that the knowledge of anatomical
variations by clinicians could help the recognition and diagnosis of pathologies such
as sialadenitis.
