Lingual Mucosal Ulceration with Bony Sequestration

— This case report describes a rare condition of lingual mucosal ulceration associated with bony sequestration following non-surgical lower molar tooth extraction of a healthy 58-year-old female patient. Clinically, she presented with a painful ulcer on the lingual aspect of the posterior mandible and noticed a sharp bone which caused irritation to the side of the tongue. The exposed bone was removed surgically, and the ulcer was completely healed. Thus, emphasizing the understanding of the causative factors of oral ulcers can help in giving a proper treatment plan.


I. INTRODUCTION
Infection and alveolar osteitis are the two most common complication following a lower third molar extraction [1]. Other complications are soft tissue injuries, root fracture, bleeding, damage of the adjacent structures and paraesthesia due to nerve injury to the inferior alveolar or lingual nerves [2]. On the other hand, lingual mucosal ulceration (LMU) with bony exposure is a rare complication that can occur following lower wisdom tooth extraction.
The lower posterior teeth usually are lingually inclined, protecting the underlying mucosa. The loss of one or more lower molars allows masticatory pressures and occlusal damage, leading to trauma to the lingual mucosa. Additionally, the mucosa covering the mandible's lingual cortex is delicate particularly in the posterior supramylohyoid region. The prominence of the mylohyoid ridge, exostosis or mandibular tori puts this area at risk for traumatic ulceration and bone denudation [3]. Due to the disruption and poor periosteal blood supply, the exposed lingual cortex is prone to ischemic necrosis and possible sequestration [4].
Although lingual mucosal ulceration with bony sequestration is uncommon in daily dental practice, oral maxillofacial surgeons are familiar with this condition, particularly in patients who have had a lower mandibular molar tooth extracted. Therefore, it is paramount for general dental practitioners to be familiar with the possible causes, differential diagnoses, and clinical presentations.
This case report will describe a rare case of lingual mucosal ulceration associated with bony sequestration following lower molar tooth extraction and its management. A 58-year-old female was referred from private dental practice complaining of a painful ulcer associated with sharp bone at the lower left lingual mucosa (Fig. 1). The ulcer developed ten days after her lower left wisdom tooth was extracted. She claimed that the extraction was uncomplicated, and they faced no difficulty. The painful ulcer was also associated with an ulcer at the lateral border of the left tongue. The systematic medical review revealed neither she is suffering from any medical illnesses including radio chemotherapy nor taking any medication. She does not smoke or consume alcohol.

Fig. 1 Exposed bone at the lingual part of the mandible
Intraoral clinical examination revealed that the lower left third molar (38) was absent. The extraction wound socket was healing fine. There was an exposed mucosal ulceration and a tiny white cortical bone ledge, approximately 2mm x 5mm in length at the lingual to 38 region, above the mylohyoid ridge. It was sharp, rough, immobile, and tender to touch. The surrounding lingual mucosa appeared reddish (erythematous) and inflamed. No discharge or active bleeding was noted. An area of halo ulceration was also presence at the lateral border of the adjacent tongue at the same level with the exposed bone. No extraoral abnormalities detected. The sharp bony ledge was removed under local anaesthesia -inferior alveolar nerve, lingual nerve and long buccal nerve were blocked. The incision was made using blade #15 to create an envelope flap. The flap was raised gently using Molt #9 periosteal elevator. A small bone rongeur was used to remove sharp bone speckles and it was smoothened with bone files. The flap was sutured with non-resorbable black silk 4/0 suture (Fig. 2). No suturing was performed at the fenestrated lingual tissue. The patient was prescribed with Paracetamol tablets and Gengigel Oral Gel to be applied four times daily. Antibiotics were not prescribed. Postoperative instruction was given including maintenance of oral hygiene with the aid of antiseptic mouthwash (chlorhexidine gluconate 2%).
At one week's follow-up, the patient reported a considerable reduction in discomfort, and the presence of granulation tissue at the location of bone exposure was identified (Fig. 3). No additional therapy is necessary. Dental panoramic tomography (DPT) showed no abnormalities detected as shown in Fig. 4. Cone beam computed tomography (CBCT) scan revealed the presence part of tiny bony portion dissociated from the lingual cortical bone in the area of 38 (Fig. 5). There was no other significant finding noticed.

III. DISCUSSION
The incidence and prevalence of lingual mucosal ulceration with bony sequestration following lower third molar extraction in the general population are unknown and rarely reported in the literature [5,6]. Although this condition is familiar among oral and maxillofacial surgery team, it can be clinical and therapeutic challenging for the general dental practitioner.
The causative factors can be local such as trauma, chronic odontogenic infections, self-inflicted or systemic factors including radiotherapy of head and neck cancer, bisphosphonate therapy, long-term corticosteroid usage and clotting disorders.
Prior to treatment, the local anatomy of the lingual medial shelves must be assessed. This is important to establish a proper treatment strategy. Referral to an oral maxillofacial surgery team is an option for management, particularly when the lesion does not respond to non-surgical intervention.
In the present case, we cannot confirm the exact etiology as the extraction was atraumatic and the patient's medical history was clear. However, the ulceration with bony sequestration following lower third molar extraction can be possibly caused by a fracture of the cortical plate, particularly on the lingual side of the socket, which is typically quite thin. The buccallingual movement that used to expand the tooth socket during tooth extraction may result in the fracture of the thin plate [7,8].
Age can be another indicator of this mechanism of injury. In elderly patient, the bone became mature and decreased elasticity. This may result in an increased incidence of bone plate fractures during tooth extraction and caused injury to the mucosa [7].
While the associated symptoms are typically mild, they can last for several weeks as the sharp irregularity undergoes bone remodeling. To alleviate pain associated with swallowing or chewing, the bony irregularity may need to be removed or smoothed.
The treatment modalities can be conservative or surgical depending on whether the patient is symptomatic or asymptomatic. Conservative treatment includes the prescription of antiseptic mouthwash, antibiotics and antiinflammatory creams which are helpful to aid the healing process [9]. A broad-spectrum antibiotic such as Amoxycillin 500 mg three times daily for five days can be prescribed to control acute phase of the condition. To reduce discomfort, anti-inflammatory medications such as Mefenamic acid, Ibuprofen, and Diclofenac can be given. Topical hyaluronic acid (HA) such as Gengigel gel also can be applied three to five times daily to aid in tissue healing. HA is a natural glycosaminoglycan that helps in activation and moderating inflammatory response. It ensures optimal hydration of the oral mucosa and promotes faster healing times. Given sufficient time, the exposed bone may become loose by itself. Since this patient is symptomatic, removing a sharp bone is advisable. There are two surgical options. The first technique involves trimming the fragment through the existing mucosal perforation, while the second technique involves raising a mucoperiosteal flap and removing the bone speckles with a surgical bur or a bone file. [10]. In this case, the latter technique was chosen as an attempt to remove the bone through the perforation may result in a larger dehiscence in the mucosa and the exposure of more cortical bone [7,10].
Similar to many other types of oral ulcers, ulcer of the tongue typically resolves on its own. Numerous researchers report that most lesions heal in 4-14 days without intervention.

IV. CONCLUSIONS
Lingual mucosal ulceration with bone sequestration is one of the post-extraction complications. Proper management which includes thorough debridement and removal of the sequestrated bone would ensure optimal healing of this affected site. General dental practitioners must be familiar with the potential etiology and clinical presentation to rule out any alarming pathology.
CONSENT TO PARTICIPATE Written informed consent was obtained from the patient for the anonymized information to be published in this article.

CONFLICT OF INTERESTS
The authors declared no conflict of interest and did not receive any funding for this article.