Oral irritation fibroma associated with the pathological migration of a primary tooth

Abstract

We report the case of a 3-year-old girl referred to our hospital dentistry service, from a public health centre, due to a 4-week-old swelling in the area of the hard palate, causing displacement of the deciduous tooth and the appearance of an interincisal diastema. The clinical characteristics suggested the possibility of a reactive fibroma and we decided to intervene surgically by means of an excisional biopsy. Histology confirmed the presumptive diagnosis. Prompt referral and early surgical care spontaneously favoured both repositioning of the displaced primary tooth and closure of the diastema. This is an infrequent lesion in paediatric patients.

Background

Children frequently present a wide variety of oral lesions and alterations of the periodontal tissues. Most paediatric conditions are benign and do not require extensive surgery.¹

Many lesions of the oral mucosa are reactive lesions. The gingiva is constantly subjected to irritants, including plaque, calculus, food impaction, defective restorations and traumatic brushing. Chronic irritation can lead to persistent inflammation that induces proliferation of endothelial cells, chronic inflammatory cells and fibroblasts. Clinically, it manifests as an overgrowth of granulation tissue, termed reactive hyperplasia.^2–4

Fibroma is one of the most common benign soft-tissue tumours of the oral cavity in adults, but it is rare in children. This tumour belongs to the group of reactive hyperplastic lesions and clinically manifests as wrong tissue repair secondary to chronic irritation of the oral mucosa.^5–8 This lesion may also cause a change in the teeth position as a result of the imbalance of the forces that normally keep it in place, a phenomenon known as pathological tooth migration.^{9 10}

Here, we describe the management of an oral reactive fibroma in a 3-year-old patient, associated with pathological tooth migration, with an atypical location in the palatal mucosa and with no evidence of a causal factor.

Case presentation

A 3-year-old girl was referred from a primary care centre to the dentistry service of Sant Joan de Déu Hospital for a painless swelling of some 4 weeks of evolution, located in the palatal mucosa of the anterior sector of the mouth. Her parents were alarmed by the slight displacement of the primary tooth. The patient had no pathological history of interest or dental trauma, and was not receiving any medical treatment, nor did she present non-nutritive sucking habits.

During the intraoral examination, complete primary dentition was observed without signs of caries, correct oral hygiene and a left lateral crossbite. Tooth 6.1 was displaced 1.5 mm into the buccal space, slightly raised with regard to the occlusal plane and associated with an interincisal diastema of 2 mm. In the palate around tooth 6.1, a rounded swelling in the palatal fibromucosa of approximately 1 cm in diameter was observed, with a sessile base, firm consistency, smooth surface and a pink colour similar to the surrounding tissue. The intraoral radiographic examination yielded no significant findings (figure 1A–C).

Figure 1.

Preoperative view. (A) Irritation fibroma. (B) Displacement of tooth 6.1 and interincisal diastema. (C) Preoperative occlusal X-ray.

Differential diagnosis

The initial diagnosis, based on the clinical appearance, was irritation fibroma. Other differential diagnoses considered were giant cell fibroma, peripheral ossifying fibroma and peripheral odontogenic fibroma.

Clinically, this fibroma is described as a firm, painless nodular mass with a smooth or irregular surface, generally less than 10 mm and of the same colour as the surrounding tissues. It may be either pedunculated or sessile and may arise in the gingiva or the buccal mucosa during the alveolar process, sometimes causing displacement of neighbouring teeth as well as diastemas.

Most fibromas have a characteristic clinical presentation, but histological examination is necessary to classify the fibroma type. Giant cell fibroma is the most prevalent form in children. From the histological point of view, stellate cells, associated with connective tissue fibrosis, are characteristic of this type of lesion.^{11 12} Ossifying fibroma presents mineralised inclusions in the form of immature bone tissue, while in peripheral odontogenic fibroma remnants of the dental lamina are observed.^{3 13}

Treatment

In view of the patient’s age and the clinical presentation of the lesion, it was decided to perform the excisional biopsy under general anaesthesia after obtaining informed consent from the parents.¹⁴

Under both general and local anaesthesia, two semilunar incisions were made by electrosurgery as far as the mucosa and periosteum, followed by debridement and curettage of the underlying bone (figure 2A–C). The lesion, which measured 0.9×0.6 mm, was fixed in formalin for subsequent histopathological examination. Given the type of mucosa in the area of the lesion, with dense connective tissue adhered to the periosteum, we decided not to suture the wound and to wait for closure by secondary intention.

Figure 2.

Intraoperative view. (A) Removal of the lesion by electrosurgery. (B) Specimen after excisional biopsy. (C) Postoperative wound.

In the immediate postoperative period, a soft warm diet was prescribed for the first 3 days, along, analgesia (paracetamol 200 mg/6 hours) and local use of chlorhexidine gel with hyaluronic acid every 8/12 hours for 7 days, in order to favour wound healing. Instructions were given regarding good oral hygiene.

Microscopic examination revealed a lesion comprising epithelial tissue and stratified squamous epithelial cells with signs of acanthosis and parakeratosis. The underlying hypocellular connective tissue contained some capillary vessels and cells such as fibroblasts, lymphocytes and plasma cells (figure 3). The stroma was reactive for vimentin and negative for CD-34, protein S 100, epithelial membrane antigen, and alpha smooth muscle actin, indicating the fibroblastic origin of the lesion.¹² These histopathological characteristics, and the absence of stellate cells, mineralised inclusions, or dental lamina residues, confirmed the diagnosis of irritation fibroma.

Figure 3.

Histological image (H&E ×10).

Outcome and follow-up

Postoperative controls showed healing to be satisfactory, with no signs of inflammation or of local recurrence. Six weeks after the excision of the fibroma, the migration of the affected tooth (incisor 6.1) had been completely reversed, the tooth’s position had improved, and the interincisal diastema had closed spontaneously (figure 4A, B).

Figure 4.

Postoperative view. (A) 15 days after surgery, occlusal and frontal view. (B) 45 days follow-up, occlusal and frontal view.

Discussion

Injuries of inflammatory and traumatic origin comprise the vast majority of soft-tissue lesions in children and adolescents, and are the most common reason for dental consultation.⁸ Within the group of oral mucosal lesions, the most frequent are reactive hyperplasias which develop in the presence of a chronic insult and mimic an exaggerated tissue repair response.¹⁵

Information regarding the prevalence of reactive hyperplasias in children is scarce, especially in the specific case of irritation fibroma. Few studies have been published to date and their results range widely, probably due to the discrepancies in the criteria used such as age range and type of injury, and also to geographical and endemic differences between the countries included in the studies.^{14 16–18} However, it has been confirmed that reactive lesions are rare before 10 years of age, especially in primary dentition, and that children are more likely to present giant cell fibromas than irritation fibromas, which in turn are more common in adult patients.^{5 15}

Cases of oral reactive fibroma related to neonatal teeth in children in the first year of life have been reported, but are considered extremely rare.^{19 20} Our case, a 3-year-old girl, also presented pathological migration of a primary tooth associated with this irritative lesion.

Shetty et al described a case of periphereal fibroma in mixed dentition hindering the eruption of the permanent tooth. Since fibromas grow slowly, the lesion may go unnoticed until it reaches a large size, and can lead to disorders such as ulceration due to repetitive trauma during chewing, failure of eruption and lip incompetence. Early diagnosis is essential for prompt intervention and for the prevention of related complications.²¹

A priori, the location of the irritation fibroma in the palate is unusual, as the risk of external trauma in this region is low. In our clinical case, no harmful antecedents could be identified, although in all probability a traumatic factor was involved that the parents had not noticed (eg, contact with a toy, a finger nail, etc). Young children often place objects in their mouth, using it as an additional sense organ. Indeed, the patient’s lateral crossbite coincided with the side of the appearance of the lesion, which is dominant during chewing.²²

The patient’s response to treatment was highly favourable. The spontaneous repositioning of the displaced tooth and the closure of the interincisal diastema improved the aesthetics of the anterior sector and created the conditions needed for the further transition to permanent dentition.

Learning points.

• Oral mucosal lesions in children should be analysed. The possibility of diagnoses that are rare in this population should not be ignored.

• In the case of irritation fibroma, early treatment in a paediatric patient favours: (1) rapid healing, (2) restoration of harmony in the affected sector of the dental arch, (3) correct masticatory function and (4) the transition to permanent dentition.

• After surgical excision of the reactive fibroma, periodontal scaling and curettage of the underlying bone are essential to prevent possible recurrences.

Ethics statements

Patient consent for publication

Consent obtained from parent(s)/guardian(s)