Giant cell-rich osteosarcoma or giant cell reparative granuloma of the mandible?

Giant cell-rich osteosarcoma (GCRO) is a rare subtype of osteosarcoma, and no literature has reported occurrence in the mandible region up to now. In this article, we report a case of GCRO originating from the mandible in a 67-year-old woman who presented a history of painless mass located in the left side of the mandible after teeth extraction. The curettage biopsy histologic diagnosis is giant cell reparative granuloma before mandibulectomy surgery, but panoramic radiograph revealed an osteolytic lesion. The tumor was completely resected with segmental mandibulectomy and soft tissue with postoperative histologic diagnosis of GCRO. The free fibula osteomyocutaneous flap was performed to reconstruct the defect of the mandible and gingival mucosa. The patient received postoperative radiotherapy and chemotherapy. The 1-year follow-up situation is fine.     

β-Tricalcium phosphate promotes cell proliferation,osteogenesis and bone regeneration in intrabony defects in dogs

ObjectiveThis study investigates the effect of the new synthetic bone grafting material, high pure-phase β-tricalcium phosphate (Cerasorb^® M, granule size 500–1000 μm), on the osteogenesis process and proliferation marker in bone marrow stromal cells (BMSCs) and its regenerative effect in the periodontal intrabony defects in dogs.DesignThe effect of Cerasorb^® M (20 and 40 mg ml^?1 for 1 and 2 weeks) on the proliferation rate of BMSCs was assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay on the proliferating cell nuclear antigen (PCNA) by immunoblotting and on alkaline phosphatase level by colourimetric assay. The regenerative effect of Cerasorb^® M in the periodontal intrabony defects in dogs was investigated by histological and immunohistochemical analysis after 3 and 6 months of grafting.ResultsIncubation of BMSCs with Cerasorb^® M for 2 weeks led to significant increase in cell proliferation rate, which was associated with increased PCNA. Cerasorb^® M significantly increased the production of alkaline phosphatase as a marker for the osteogenic stromal lineage and for differentiation and bone formation in BMSCs after 2 weeks. In the histological features and immunohistochemical analysis of PCNA of the intrabony defects in dogs augmented with Cerasorb^® M, osteoid tissue with a plate-like structure and cellular mesenchymal proliferation besides osteoid islands joined by bridges were observed after 3 months. Six months after the implantation, the Cerasorb^® M granules were replaced by abundant new plate-like bone besides PCNA-enriched, small, oval-shaped mononuclear cells and multinucleated-giant cells that were attached to newly formed bones. No remains of the Cerasorb^® M granules could be seen after 3 and 6 months with the newly formed plate-like bones and no histological sign of inflammatory reaction or formation of foreign-body granulomas.ConclusionCerasorb^® M may induce cell proliferation via induction of PCNA that may induce early osteogenesis and bone formation. Cerasorb^® M regenerated the bone completely in intrabony defects and that this regeneration was highly associated with PCNA expression in different cell lineage.     

Does preservation of the socket decrease marginal bone loss in the mandible after extraction of first molars?

The quality of the bone plays an important part in marginal bone loss (MBL) around dental implants. The aim of this study was to compare MBL around implants the sockets of which had been preserved with the bone around healed sites in the mandible after extraction of first molars. It was a prospective, cohort study in which subjects were divided into three groups (n = 30 in each): dental implants were placed six months after preservation of the socket in the first group, eight weeks after tooth extraction in the second, and six months after tooth extraction in the third. The changes between the marginal bone level after loading of the implant and 12, 24, and 36 months later were considered to be the MBL. Age and sex were the variables studied, the condition of the bone (healed socket or preservation) was a predictive factor, and MBL was the outcome. Analysis of variance was used to compare MBL and age among groups. There were no differences in the mean MBL among the three groups 12, 24, and 36 months after loading (p = 0.55, p = 0.22, p = 0.38, respectively). Preservation of the socket did not seem to affect MBL of the first molar of the mandible.     

Versatility of uniplanar prearthoplastic distraction osteogenesis in the correction of post-ankylosis facial deformities—a report of five different cases

Purpose

Unilateral or bilateral ankylosis can lead to severe micrognathia and facial deformity that requires multiple, often, staged surgical corrections. To date, there is no ideal treatment modality that satisfactorily corrects the complex anatomy, restores the ramal height, and corrects the micrognathia and microgenia. Distraction osteogenesis has been acclaimed as a successful modality for the treatment of such deformities. It is a cost-effective approach with low morbidity and less relapse thus providing better functional and esthetic outcomes. It allows the surgeon to correct the deformity in various planes by using various devices by changing osteotomy designs and vectors, with simultaneous hard tissue and soft tissue reconstruction.

Patients and methods

Here, we present a series of five cases where different types of distraction osteogenesis were combined with various other procedures to correct post-ankylotic facial asymmetry. In one case, simultaneous maxillo-mandibular distraction [Molina’s technique] was used.

Results

All patients showed significant improvement in function and esthetics. Outcome assessment was made using clinical photographs and radiographs.

Conclusion

Pre-arthroplastic distraction osteogenesis is a versatile cost effective approach that can be customized for every patient based on their needs.

     

Histological and histomorphometrical comparative study of β-tricalcium phosphate block grafts and periosteal expansion osteogenesis for alveolar bone augmentation

This study evaluated local tissue reaction around the β-tricalcium phosphate (β-TCP) block and compared results with β-TCP block grafting and periosteal expansion osteogenesis (PEO). The mandibular premolars were extracted from five dogs and buccal corticotomy was performed. Narrow alveolar ridge models were created at 4 weeks. The β-TCP block graft, such as veneer graft, was used on the right side and PEO using β-TCP block on the left side. Changes of alveolar width, histological findings and histomorphometrical analysis were evaluated. There were no problems with materials at any of the sites at any time. In both groups, the width increased after surgery and results were stable 8 weeks after surgery. Newly formed bone tissue was observed inside the β-TCP block in both sides. Histological findings differed especially at the division between mandibular bone and β-TCP block. Histomorphometric analyses revealed that β-TCP had been absorbed (mean decrease 28%) and new bone had formed (mean increase 43%) at 8 weeks postoperatively on both sides. The β-TCP block worked as a space-maker under the soft tissue, including the periosteum, and acted as a substitute for original bone. This bone substitute was effective material for bone augmentation in both methods.     

Squamous cell carcinoma of the mandible – Patterns of metastasis and disease recurrence in dependence of localization and therapy

IntroductionOral squamous cell carcinomas exhibit distinct patterns of disease progression, depending on their localisation. This study aimed to evaluate clinicopathological data in patients with tumors of the mandibular alveolar process, to facilitate risk assessment and therapy planning.Materials and methodsA retrospective cohort study was designed including patients with squamous cell carcinoma of the mandibular gingiva. Clinical and pathological data were collected to determine the rate of cervical metastases and clinical outcomes depending on tumor stage, localization (anterior, intermediate and posterior) and the extent of tumor resection.Results120 patients were included in the analysis. Rate of metastases was 42.6%. Tumors of the anterior part of the mandible exhibited significantly higher rates of bilateral metastases (anterior: 85.7%, intermediate: 15.8%, posterior: 4%, p < 0.001) and local recurrence (anterior: 25%, intermediate: 16.3%, posterior: 5.5%, p = 0.03) compared to posterior malignancies.ConclusionTumors of the anterior segment of the mandible are characterized by high rates of metastases and local recurrence. Therefore, we propose radical segmental resection and bilateral neck dissection in those patients.     

External pin fixation for stabilization of the mandible—comeback of a method: historical review and first experiences with the ‘mandible external fixator’

Background

The market-release of a modified ‘mandible external fixator’ appliance prompted us to reconsider the issues of pin fixation.

Materials and methods

The first product line of the ‘mandible external fixator set—Phase1’ (Synthes Maxillofacial®, Paoli, USA) contains the three classical basic components: percutaneous pins, clamps, and pre-bent connecting rods. The innovative features are a lightweight titanium construct and the snap-on design of the clamps. The framework is assembled by a single connecting bar (monofixator) in the so-called visor-style technique.

Indications

The indication was restricted to: (1) pathological fractures, e.g., in infected osteoradionecrosis; (2) resectional defects; and (3) emergency care of mandible fractures in a multi-piece, heavy comminution, or defect pattern.

Patients

The mandible external fixator was used in a series of ten patients (all male, 39–73 years), for head and neck tumor sequelae in eight cases (n?=?5—curatively, n?=?3—palliation) and in two polytrauma cases.

Results

All patients had benefited from the functional restitution of the mandibular continuity avoiding major surgical exposure and additional soft tissue damage. The application using a ‘visor-style technique’ was appropriate for bridging defects or single comminution zones (n?=?9). In the emergency care of a polytraumatized patient with multifragmentation all over the mandible divisions, it did not contribute to an adequate realignment. In curative tumor treatment (patients n?=?5), a conversion either to internal fixation (n?=?2) or revascularized bone grafting (n?=?3) ensued after prolonged intervals of 40–170 days. Pin track infections or loosening did not occur.

Conclusion

The hallmark of external pin fixation is its atraumatic soft tissue management. Hence, it offers peculiar options in singular comminution or defect areas associated with bone pathology and/or soft tissue alterations.     

Is there an asymmetry of the condylar and coronoid processes of the mandible in individuals with unilateral crossbite?

Objectives:To evaluate if there is a true skeletal asymmetry of the condylar and coronoid processes of the mandible in growing individuals with unilateral posterior crossbite (UPC) either functional or not.Materials and Methods:This cross-sectional study screened a total of 1120 cone beam computed tomography (CBCT) scans based on inclusion and exclusion criteria. The final sample comprised 20 CBCT images of individuals with UPC and 19 CBCT images of individuals without transverse malocclusion. The lengths of the condylar and coronoid processes were measured to evaluate asymmetry, as well as the magnitude of the mandibular lateral deviation in the UPC group.Results:There was a significant difference between the lengths of the affected and nonaffected sides of the coronoid processes in the UPC group (P < .01). The same was not observed in the condyle in the UPC group (P > .05). There were no significant differences between the groups (P > .05).Conclusions:Although no differences in the condyle were observed, the coronoid process was asymmetric in individuals with UPC. However, this asymmetry was not considered to be clinically significant.     

Alteration of the actin cytoskeleton and localisation of the α6β1 and α3 integrins during regeneration of the rat submandibular gland

ObjectivesActin filaments, which are regulated by signal transduction via integrins, play important roles in the regulation of cell differentiation and polarity. The aim of this study was to assess alterations in the cytoskeleton and the localisation of integrins during regeneration of the rat submandibular gland.DesignAfter obstruction for 7 days, the regenerating glands were collected at days 0, 1, 3, 7, 14 after duct release for analysis of regeneration. Alterations in the actin filaments were examined using phalloidin, which specifically binds to filamentous actin (F-actin), and the distributions of the α6β1 and α3 integrins were examined immunohistochemically.ResultsF-actin was strongly localised at the apical region in the intercalated ducts of normal and day-14 glands and in duct-like structures during the regenerative process. Thereafter, actin accumulated at the basement membrane in mature acinar cells. A temporo-spatial correlation was found between the apical distribution of F-actin and α3 integrin staining. Diffuse α6β1 integrin staining, which occurred at a distal site in α3 integrin-positive cells, was observed in immature cells at day 3. At day 14, α6β1 integrin was detected at the basement membrane in terminal differentiated acinar cells.ConclusionThese findings suggest that duct-like structures have the same properties as intercalated ducts, that alterations in α3 to α6β1 integrins regulate the generation of acinar cells from duct-like structures, and that the α6β1 integrin is involved in the differentiation of acinar cells during regeneration of the rat submandibular gland.     

Gorham’s disease of the mandible: radiological features

The most conspicuous element of Gorham’s disease is its radiographic features, wherein massive disappearance of the mandible is observed. We report a case of an adolescent boy with massive osteolysis of the mandible in whom the diagnosis of Gorham’s disease was made. A 14-year-old boy was referred to the Department of Oral and Maxillofacial Surgery, Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur, for the management of a massive mandibular deformity. He was diagnosed with a hemangioma-like lesion at 1 year of age. The disease had progressed for an unknown number of years. Plain X-rays and computed tomography images were examined for reconstructive surgery planning. Gorham’s disease is self-limiting, but has catastrophic results. The role of imaging is huge, particularly for reconstructive surgery planning.     

Bone sialoprotein-induced reparative dentinogenesis in the pulp of rat’s molar

Bone sialoprotein (BSP), an osteogenic protein (OP), mixed with a carrier, was implanted in the pulp of rat first upper molars (OP group). Cavities were prepared with dental burs and pulp perforation was carried out by pressure with the tip of a steel probe. After 8, 14, and 30 days, the rats were killed and the pulps of the OP group were compared with (1) a sham group (S group), (2) a group where the carrier was implanted alone (C group), and (3) capping with calcium hydroxide (Ca group). After 8 days, a few inflammatory cells were seen, mostly located at the pulp surface near the perforation. In the Ca group, a dentin bridge started to form, in contrast to the other groups. After 15 days, globular structures were seen in the pulps of the S and C groups. A reparative osteodentin bridge isolated the pulp from the cavity in the Ca group. Variable reactions were seen in the OP group, with some evidence of cell and matrix alignments or plugs of osteodentin in continuity with an inner layer of reparative dentin. After 30 days, irregular osteodentin formation was observed in the pulps of the S and C groups, with a tendency for globular structures to merge, but with interglobular spaces filled by pulp remnants. In the Ca group, osteodentin was observed in the mesial part of the pulp chamber. In the BSP-implanted group, the osteogenic protein stimulated the formation of a homogeneous dentin-like deposit occupying most of the mesial part of the pulp. Apparently, BSP stimulates the differentiation of cells which secrete an organized extracellular matrix more efficiently than any other capping material used so far. Altogether, the results reported here support that bone sialoprotein displays novel bioactive properties and is capable of stimulating in 1 month’s time the development of a thick reparative dentinal tissue in the pulp, occluding the perforation and filling the mesial third of the pulp chamber. Received: 13 October 1999 / Accepted: 6 December 1999     

Gorham–Stout disease of the mandible: case report and review of literature of a rare type of osteolysis

Oral Radiology - Gorham–Stout disease (GSD) is a rare form of osteolysis, the aetiology and pathogenesis of which remains controversial to this date. Although more than 200 cases of GSD have...     

Synchrotron μCT imaging of bone,titanium implants and bone substitutes – A systematic review of the literature

Today X-ray micro computer tomography (μCT) imaging is used to investigate bone microarchitecture. μCT imaging is obtained by polychromatic X-ray beams, resulting in images with beam hardening artifacts, resolution levels at 10 μm, geometrical blurring, and lack of contrasts. When μCT is coupled to synchrotron sources (SRμCT) a spatial resolution up to one tenth of a μm may be achieved. A review of the literature concerning SRμCT was performed to investigate its usability and its strength in visualizing fine bone structures, vessels, and microarchitecture of bone. Although mainly limited to in vitro examinations, SRμCT is considered as a gold standard to image trabecular bone microarchitecture since it is possible in a 3D manner to visualize fine structural elements within mineralized tissue such as osteon boundaries, rods and plates structures, cement lines, and differences in mineralization.