Bone remodelling after minimally invasive surgical management of a recurrent florid cemento-osseous dysplasia in a Caucasian woman – 18 years follow-up of a unique case - A case report

Abstract

Introduction and importance

Florid cemento-osseous dysplasia (FCOD) is a multifocal fibro-osseous tumour originating from the periodontal ligament that presents as being rare, benign and slow-growing. The lesion is characterised by the replacement of regular bone-structure with fibrous tissue and dysplastic bone. Depending on localisation, the initial characteristics of FCOD resemble those of periapical lesions of inflammatory origin.

Case presentation

We report on the current findings relating to the case of a 39-year-old Caucasian woman, who initially had persistent paresthesia of the right alveolaris inferior nerve (NAI) for longer than 2 weeks. The orthopantomogram showed multiple bilateral periapical radiolucency and a biopsy was indicated to rule out malignancy. Four years later, the radiolucency occurred once again in region 37, suggesting a recurrence of the lesion. Therefore, another minimally invasive surgery had to be performed, which revealed a bone cavity. Two years later, the bone of the affected region almost completely regenerated.

Clinical discussion

We were aware that an invasive treatment could lead to infection of the hypovascular lesion. Because of the paresthesia, a biopsy was essential. Unexpectedly, the second minimally invasive surgical treatment was a significant success, as the bone lesion regenerated almost completely.

Conclusion

The follow-up of this case was documented over more than 18 years. To date, this is the longest documented case of a FCOD. Minimally invasive surgical treatment of such lesions may lead to better bone regeneration and even a better quality of life for the patient.

Highlights

• •FCOD is a multifocal fibro-osseous tumour originating from periodontal ligament.
• •The recurrence of the lesion, thus a relapse, was seen after four years.
• •Minimally invasive surgical treatment of FCOD can lead to better bone regeneration.

1. Introduction

Osseous dysplasia includes a large spectrum of non-neoplastic, fibro-osseous transformations.

First introduced in 1976, the term florid cemento-osseous dysplasia (FCOD) describes an extensive variant of a reactive fibro-osseous process, known as cementoma [1].

The 5th Edition of the classification of bone-related lesions published by the World Health Organization in 2022 describes cemento-ossifying fibromas, benign cementoblastomas, and benign lesions based on: sex, age, location, as well as clinical, radiological, and histopathological characteristics. However, this updated classification system still does not account for the various phenotypes of fibro-osseous lesions [2].

FCOD is a rare, benign, multifocal fibro-osseous dysplastic process affecting tooth-bearing areas of the jaw. It is characterised by the growth of osseous tissue and dense acellular cementum in a fibrous stroma, replacing normal trabecular bone [3]. The most common fibro-osseous lesions encountered in clinical practice are the cemento-osseous dysplasia [2]. They can be divided into three subtypes according to their clinical and radiological features: periapical cemento-osseous dysplasia, focal cemento-osseous dysplasia, and FCOD [4]. Typically, normally structured bone is replaced with fibrous, mineralised tissue [2].

Regarding radiological examinations, the lesion manifests as multiple, lobular, well-marginated, non-expansile intraosseous masses of varying internal lucency and sclerosis, surrounding the root apices of vital teeth. Involving the apices of vital teeth, FCOD is a well-defined clinicoradiologic entity. It may occur in multiple quadrants of the jaw and usually arises in the 4th or 5th decade of life [3].

While all CODs share similar microscopic features, FCOD is distinguished by a multifocal distribution, involving two or more quadrants of the maxilla and mandible, often in a bilateral symmetric fashion. Female patients, specifically of African American ethnicity, are more often affected than their male counterparts. The age at the time of diagnosis ranges from 19 to 76 years [5].

The stages of FCOD can be classified into three phases. First, the lesions are located periapically and are radiolucent (osteolytic phase). Later, the bone combines with the connective tissue (cementoblastic phase) until the bone becomes radiopaque (osteogenic phase) [6].

A systematic review of the literature in 2003 assessed 159 cases of FCOD. In 59 % of cases, the lesion occurred in African Americans, 37 % of cases were Asians, and 3 % were Caucasians. Of all patients, 97 % were female [7]. The disease mainly affected the mandible, and the stage of the lesion was directly correlated with age [8].

The origin is unknown, but currently, a reactive process is assumed. In most cases, the patients have no related heredity and no family history of similar lesions [9].

Because of the asymptomatic presentation of FCOD, the lesion can remain undetected for several years and is therefore often diagnosed by coincidence during regular radiological examinations [10]. In severe cases, FCOD can result in bone expansion accompanied by pain and facial deformation [11]. FCOD must be distinguished from other dysplastic, neoplastic, and infectious processes of the jaw with overlapping radiological features, including periapical infections, Paget's disease, chronic diffuse sclerosing osteomyelitis, fibrous dysplasia, Gardner syndrome, or osseous metastases [3]. FCOD is not associated with other skeletal abnormalities or biochemical markers and combined with the absence of other systemic manifestations, this contributes to the uncertain diagnosis [12].

Due to their rarity, histological diagnosis of fibro-osseous lesions is challenging, as they are easily confused with similar tumors [3], [5].

Unnecessary biopsy and surgery should be avoided, as the hypo-vascular lesions are easily susceptible to infection, osteomyelitis, and bone necrosis⁸. Accordingly, it is important to be aware of other medical conditions to prevent misdiagnosis, which would result in an inappropriate treatment [3]. Especially prior to endodontic treatment, a vitality test is necessary as the characteristics of initial FCOD are similar to those of periapical lesions of inflammatory origin [13]. The gold standard treatment of asymptomatic, non-infected FCOD consists of regular/routine radiographic follow-up appointments.

Sensory disturbances in the region of the nervus alveolaris inferior (NAI), including anesthesia, paraesthesia, hypoaesthesia, and hyperaesthesia, are well-known complications of malignant tumors and of dental and maxillofacial operations [14]. Infections and overfilled root-canal treatments can also irritate or disturb the nerve [15]. As a result, the sensitive supplied area of the ipsilateral lower lip and surrounding skin can be affected. The majority (approximately 90 %) of these complications is only temporary and resolve within 8 weeks. However, if the paraesthesia persists beyond 6 months, it is deemed to be permanent [16].

The patient was managed in a private dental office. We report the present case in accordance with the SCARE criteria [17].

2. Presentation of case

We report on the latest findings relating to the case of a 39-year-old Caucasian woman with unremarkable drug, family, and psychosocial histories. Initially, she had persistent paresthesia of the right NAI for longer than 2 weeks, describing throbbing pain at the lingual and buccal side of the mandible during a clinical examination. The orthopantomogram revealed multiple radiolucent, periapical lesions in different sizes and shapes. The findings were non-symmetrical, bilaterally arranged, and distributed over the entire lower jaw. Teeth 36 and 37 showed a large radiolucent periapical area, only separated via a small sclerotic septum. The origin of the lesion at tooth 36 appeared to be the distal radix and clearly expanded over to the apical region of tooth 35. The canalis alveolaris inferior sinister appeared to be infiltrated at region 37. Further radiolucent lesions could be found periapically at region 33, almost reaching tooth 32. On the right side of the mandible, similar lesions could be found at regions 46, 42, and 41. Yet, the nerve channel appeared to be intact. The tumorous lesions to the front almost appeared as a single, large body. Although every pathological lesion was situated around the radices, no root resorption was visible, and the performed sensibility test showed a positive result for all involved teeth. In contrast, no radiological pathologies could be found in the upper jaw. On an orthopantomogram obtained 13 years earlier, some of the radiolucent lesions of the lower jaw could already be assumed at regions 37, 36, 32, and 46 (Fig. 1 A–C).

Fig. 1.

A. OPT: Panoramic radiograph acquired over 13 years before surgery. Note the elucidations at the first molars in the mandible. B. OPT: Panoramic radiograph one year before surgery. Note the increasing of the FCOD in region 36/46; 31; 42. C. Panoramic radiograph shortly before the operation. D. Panoramic radiograph four year after surgery. Note the reoccurring radiolucency E. Panoramic radiograph one year after the attempted minimally invasive removal of the lesion. Note the regeneration of the lesion.

A computed tomography (CT) scan of the mandible 13 years after the first CT, a high-resolution 1-mm stratification of the horizontal mandibular branch, showed multiple resorption zones. They were periapically directly in the area of incisors 31, 41, and 42. In addition, osteolysis was observed periapically in the area of premolar 35 and molars 36, 37, 46, and 47. The corticalis was thinned and displaced ventrally, whereas the alveolar canal remained intact. The lesion was more distinct on the left side than on the right. There was no periosteal reaction and no spicules (Figs. 2 (A–D), 3 (A–D) and 6 (A–B)). Based on the medical history, clinical symptoms, and radiological findings, a differential diagnosis of fibro-osseous disease was decided.

Fig. 2.

A–D. CBCT images, which show the successive layers of the computed tomography in the horizontal cut.

Fig. 3.

A–D: CBCT images, which show different layers of the CT in the horizontal cut.

Fig. 6.

A. CBCT horizontal view of the mandible. B. CBCT vertical view.

C. CBCT horizontal view of the mandible. D. CBCT vertical view of region 37.

However, due to the existing paraesthesia in the area of the left NAI, a histopathological examination was necessary to exclude malignancy. The samples were acquired from the area around region 36. First, the surgical bur was used under water-cooling conditions and then the bone was removed with the chisel technique. The semi-lunar flap was selected as the ideal access path for the sampling Fig. 4 (A–D).

Fig. 4.

A. Buccal intraoperative view before surgery. B. Intraoperative view after surgical opening. C. OP-situation after bone minimally invasive removal of the lesion. D. The removed bone lesion.

The histological examination revealed calcifications or map-type neoplasms in front of a relatively cell-rich, fibrous stroma, with a small number of histocytic cell elements. The histological appearance was compatible with the diagnosis of FCOD Fig. 5 (A–D). A minimally invasive surgical removal of the lesion was performed, resulting in the disappearance of the paraesthesia of the bottom lip. Six months later, the patient described a feeling of intense painful pressure in the area of the former FCOD. Although uncommon and aware of the possible risks, we decided to perform a surgical procedure. Our aim was to partially remove the tumour, especially at the area of the nervus mandibularis, which we suspected was the origin of the mentioned symptoms. At that time, the patient also received preoperative antibiotics. Using an intraoral approach, the patient underwent surgery under general anesthesia. Initially, a mucoperiosteal flap was raised. However, no evidence of FCOD could be detected upon specimen examination. The specimen appeared as regular modelled bone with physiological circulation. The patient received postoperative antibiotics, a nonsteroidal anti-inflammatory agent, a proton pump inhibitor, and was discharged in stable condition. For the following 6 months, the patient remained under regular follow-up. No further increases in size of the lesion or newly occurred spots were detected. This astonishing case has been documented in detail in a first paper up to this point and will now be described further [18]. An orthopantomogram taken at a routine checkup 4 years after the last surgical intervention (16 years after the first referral) showed a newly appearing radiolucency apically of tooth 37. The radiolucency measured approximately 1.5 cm in diameter with sharply defined margins. Furthermore, the cortical bone presented itself as being irregularly dissolved by this process, suggesting a recurrence of the lesion. A (Computer bone cone tomography) CBCT was taken, confirming the radiolucency located at the roots of tooth 37, showing no evidence of change at the roots. The presented cortical bone thinned and at the lingual region of 36 it was undetectable (Figs. 1 (D) and 6 (C–D)).

Fig. 5.

A–D. Histological findings in different enlargements (200 μm; 100 μm; 50 μm). It shows the mixture of bone and connective tissue.

Due to the size of the lesion, a referral to the University Hospital was indicated. Initially, a biopsy was requested, which we attempted to perform. First, a mucoperiosteal flap was raised under local anesthesia. After a subsequent small osteotomy, the cavity we encountered was without any contents. Thus, the defect was closed with sutures (Ethicon, Germany) and the patient received a nonsteroidal anti-inflammatory agent and was discharged home in a stable cardiorespiratory condition.

Post-operative follow-ups showed good wound healing with no further complications.

2 years after this procedure, the apical radiolucency of the tooth is radiologically almost non-existent compared to the preoperative radiograph. It appeared that the original rounded shape had changed to an oval extension. The contour of the cortical bone could be restored at the mandibular margin, but small radiolucent areas remain and are still with a fully continuous contour Fig. 1 (E). The patient was satisfied with the treatment outcome and, to date no further surgery or any other form of therapy was initiated.

3. Discussion

We report on an exciting case that was previously published in 2018 [18]. At that time, we described about the paresthesia of a Caucasian patient in direct relation to an FCOD. Due to the existing paresthesia, a biopsy had to be taken to exclude malignancy. Nevertheless, the case took a unique turn in the further course, because after the FCOD flared up again with new clinical symptoms and was more pronounced in region 37 than ever before, another minimally invasive procedure was performed, showing that this could thus promote bone regeneration.

Therefore, in the case described over a period of 18 years, a success of bone regeneration was recorded and thus a new therapeutic approach was presented.

Then, we were aware that an invasive treatment (e.g. biopsies) may lead to infection of the hypovascular lesion, and surgical intervention should be avoided due to the risk of infection or osteomyelitis. However, the pathologist's assessment remains the most crucial factor in determining a definitive diagnosis that will lead to an appropriate treatment [19]. The paresthesia's dull pressure sensation disappeared after surgery, resulting in an improved quality of life for the patient. As the FCOD-like symptoms reoccurred, the second surgical intervention in region 37 could not be avoided either. This intervention resulted in a success, as a significant improvement in bone quality was noted two years after the procedure. There was no evidence of infection, osteomyelitis, or bone necrosis of the hypovascular lesions. Initially, we considered that the best therapy for our patient was conservative symptom relief and further observation. However, after a minimally invasive osteotomy of the lesion, a haemorrhage was seen in the cavity of the defect, followed by the regression of the lesion. Therefore, these types of invasive treatment options may be goal-directed and beneficial in successfully treating such cases.

Recurrence of FCOD has been noted in one case, but as early as 18 months after removal. Moreover, in that case the recurrence was not treated with the same approach, resulting in persistent intermittent pain. Finally, as previously recommended, we also consider that radiologic diagnosis is a crucial aspect of the postoperative follow-up because FCOD can reoccur years after complete excision, as described in this case [20].

4. Conclusion

The follow-up of the lesion in this case could be documented over more than 18 years. As far as we know, this is the longest documented case of an FCOD in the literature to date. The lesion reoccurred four years after the first surgical excision, increased in size, and the area was able to regenerate after a minimally invasive osteotomy. Therefore, we now conclude that the risk of opening hypo-vascular lesions may be justified and does not necessarily lead to infection, osteomyelitis, or bone necrosis. Rather, as shown in this case, minimally invasive surgical management of such lesions may lead to improved bone regeneration and even an enhanced quality of life for the patient due to the disappearance of symptoms. Finally, radiologic follow-up is crucial, as FCOD may be recurrent, even years after complete removal.

Consent

The patient received a thorough explanation of this report gave her oral and written informed consent to be included in this report as well as for publication of these case, anonymous data, and pictures. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

Ethical approval

The ethical approval has been exempted by our institution.

Funding

Not applicable.

Author contribution

Pascal Grün and Benedikt Schneider: study concept and design, writing the paper. Pascal Grün, Patrick Bandura, Florian Pfaffeneder-Mantai and Ditjon Bytyqi: data collection, analysis and discussion of data. Dritan Turhani: final approval of the version to be published. All authors read and approved the final manuscript.

Provenance and peer review

Not commissioned, externally peer reviewed.

Guarantor

Dritan Turhani.

Research Registration Number

Not applicable.

Conflict of interest statement

Not applicable.