[The cross-plastic correction of the soft tissue defect on the neck with the use of a pectoral flap harvested from the opposite side]. / Perekrestnaya plastika defekta myagkikh tkanei shei pektoral'nym loskutom s protivopolozhnoi storony.

The authors describe a patient presenting with initially multiple metachronous cancer spreading over the right-handed side of the mouth floor and the right-handed part of the lower jaw. The patient who underwent cross-plastic surgery for the correction of the extensive soft tissue defect on the neck with the use of the musculocutaneous pectoral flap with the axial blood supply is described. The observation during the 14 year follow-up period confirmed the good functional outcome of the treatment.

Spontaneous regeneration of bone after resection of central giant cell lesion: a case report.

There are several treatment modalities to date for central giant cell granuloma including conservative treatment and surgical treatment with often planned reconstruction of the bony defect. Spontaneous bone regeneration of mandibular defects following complete resection of mandible has rarely been reported in the literature. We report a case of spontaneous bone formation after resection of a central giant cell granuloma in the anterior mandible of a pediatric patient and the importance of maintaining the periosteum during surgical resection as a rare case report.

Clinical Study of Reconstruction Plates Used in the Surgery for Mandibular Discontinuity Defect.

BACKGROUND/AIM: Postresective mandibular reconstruction is common in cases of oral and mandibular tumors. However, complications such as plate fracture and/or plate exposure can occur. The purpose of this study was to analyze complications and survival of reconstructive plates used to correct mandibular defects caused by oral cancer. PATIENTS AND METHODS: Clinical and radiological data from 34 patients were analyzed. Only discontinuous mandibular defect cases were included in this study. All cases were classified using the Hashikawa's CAT and Eichner's classification methods. Then, we determined whether these classifications and clinical treatment methods were significantly related to complications. RESULTS: Complications after mandibular reconstruction occurred in 10 of 34 patients, specifically, two plate fractures, one screw fracture, and seven plate exposures occurred. The plate fractures occurred 5 and 6 months after operation, and the screw fracture occurred 39 months after operation. Using the Hashikawa's CAT classification, the two cases of plate fracture were one of AT type and the other of T type, and the screw fracture was AT type. Using Eichner's classification, all three cases of plate and screw fractures were B2 type. CONCLUSION: We suggest that plate and screw fractures were caused by the type of mandibular defect and bite force.

Comparison of food mixing ability among mandibulectomy patients.

Many papers have been published on surgical mandibulectomy and reconstruction. However, only a few reports refer to masticatory function after prosthodontic treatment in mandibulectomy patients. The aim of this study was to investigate the masticatory function of mandibulectomy patients. Twenty-three subjects (10 males and 13 females, with an average age of 63 years) participated in this study: 11 subjects who had undergone unilateral marginal mandibulectomy, six subjects with unilateral segmental mandibulectomy with reconstruction and six subjects with hemimandibulectomy without reconstruction. Mixing Ability Index (MAI) was used to measure masticatory function on the non-defect side and on the defect side with a prosthesis installed. Comparisons were carried out among the marginal, segmental and hemimandibular groups and between the non-defect side and the defect side. Consequently, our study indicates these results. On the non-defect side, a significant difference was found between the marginal and the segmental groups, and between the marginal and the hemimandibular groups. In the marginal and the segmental groups, a significant difference was found between the non-defect and the defect sides. In conclusion, our study suggests that MAI is an adequate tool to study the masticatory function in mandibulectomy patients, the masticatory function of the mandibulectomy patients is more impaired than that of the ordinary removable partial denture patients, and that surgical intervention affects the masticatory function on not only the defect side but also the non-defect side in mandibulectomy patients.

Mandibular metastasis as the first clinical indication of occult lung adenocarcinoma with multiple metastases: A case report.

RATIONALE: Although metastases to the oral and maxillofacial region (OMR) are rare, the lung is the most common primary site metastasizing to the OMR. PATIENT CONCERNS: An 83-year-old woman presented with reports of trismus, occlusal discomfort, swelling, and spontaneous pain in the right buccal region. Despite the absence of abnormal chest imaging findings, immunohistochemical analysis of biopsy specimens of the mandible and the thyroid indicated that the patient had multiple metastases from a lung poorly differentiated adenocarcinoma. DIAGNOSES: Metastases to the OMR and the thyroid from an undiscovered lung adenocarcinoma. INTERVENTIONS: Gefitinib was started as first-line chemotherapy, and zoledronic acid was administered for bone metastases. OUTCOMES: Follow-up imaging examinations showed ossification and deformation of the right mandibular ramus and the condylar process. Although 2 years have passed since the first visit to our hospital, lung lesions have not been confirmed by imaging examinations. LESSONS: Clinicians should consider the possibility that symptoms in the OMR may be the first clinical sign of an undiscovered distant primary tumor, and the primary tumors may not be detected by imaging examinations even when metastases to the OMR are revealed.

Transforming growth factor beta 2 in epithelial differentiation of developing teeth and odontogenic tumors.

Dysregulation of TGF beta 2, a modulator of cell growth and differentiation, can result in uncontrolled growth and tumor formation. Our comparative studies on the expression of TGF beta 2 mRNA and protein indicate that TGF beta 2 may primarily be a regulator of epithelial differentiation during tooth development (between 13 and 20 gestational wk) and tumorigenesis of odontogenic neoplasms. A paracrine mode of action for TGF beta 2 in early human tooth germ (cap/early bell stage) is suggested by location of mRNA in the mesenchyme surrounding the tooth germ, whereas protein is found in the epithelial dental lamina and enamel organ. During the late bell stage, TGF beta 2 gene expression shifted from the mesenchyme to the odontogenic epithelium and was colocalized with protein, suggesting an autocrine role for the terminal differentiation of ameloblasts. In odontogenic tumors of epithelial origin (ameloblastomas) and epithelial-ectomesencymal origin (ameloblastic fibromas), TGF beta 2 mRNA was mostly located in the mesenchymal tumor component and protein in the epithelial tumor component. Odontogenic ectomesenchymal tumors (myxomas) were not associated with TGF beta 2 mRNA and protein expression. The results imply that TGF beta 2 may play an important role in epithelial-mesenchymal interactions in human tooth morphogenesis and development of odontogenic tumors.

Axial four-dimensional computed tomographic images to analyze crosswise differences in protrusive condylar movement in patients who underwent mandibulectomy and free flap reconstruction.

OBJECTIVE: Few studies evaluate condylar movement following mandibular reconstruction. The main objective of this study was to show that axial four-dimensional computed tomography (4DCT) could visualize bilateral protrusive condylar movement directly. We used axial 4DCT images to assess condylar protrusion in patients who underwent mandibular reconstruction. METHODS: We enrolled seven healthy volunteers (median age 30 years, range 27-38 years) and seven patients (median age 65 years, range 52-80 years), who underwent mandibulectomy (segmental in five, hemi in one, marginal in one) and free flap reconstruction (using the fibula in six and the radial forearm in one). Six study subjects were instructed to masticate a cookie during the 4DCT scan (the seventh made chewing motions). The distance between the most anterior and posterior positions of the bilateral condyles on 4DCT (axial view) images was then measured and compared between controls and patients using the Mann-Whitney U-test. RESULTS: The crosswise difference in the distances of condylar protrusion was significantly greater in patients than in the controls. CONCLUSION: Axial 4DCT images can visualize a bilateral condylar protrusive path. Axial 4DCT images for patients who have undergone mandibulectomy and reconstruction may be useful for evaluation of functional movement of condyles.

[Functional recovery with prosthetic management for segmental resection of the mandible without reconstruction].

PATIENT: The patient, a 54-year-old male, consulted the Oral Surgery Department of Iwate Medical University Hospital with a complaint of a mass in the left oral base in June 1992. In September 1992, the patient was diagnosed as having cancer in the left mandibular base, and the tumor was excised by resection of the entire cervical region on the left side. Since radiation osteonecrosis in the left mandible and mandibular fracture were detected, segmental excision of the left mandible was performed in March 1993. Although the postoperative course was good without reconstruction, the patient consulted the Second Prosthetic Department to achieve functional recovery in February 1996. This patient had no occlusal contact between the maxilla and mandible because the mandible shifted to the affected side. After fixation of a mandibular prosthetic appliance for the defective mandible, a palatal plate for the maxilla in occlusal contact with the mandibular dentition and mandibular prosthetic appliance were fixed in November 1997. After fixation of a new mandibular prosthetic appliance and dentures for the maxilla with palatal ramp in April 2001, masticatory function was observed to have improved with control of the mandible. DISCUSSION: To prevent the mandibular shift and improvement of the masticatory function, a palatal plate with a palatal ramp in the occlusal contact region was fixed, and a balance of the masticatory muscles could be maintained. An evaluation of the level of improvement in the masticatory function and the pronunciation function indicated that the mandibular prosthetic appliance and palatal plate with a palatal ramp in the occlusal contact region increased the kind of food that the patient could take. Moreover, by enlarging the narrow Donders space, the pronunciation was improved. CONCLUSIONS: Fixation of a palatal plate with a palatal ramp in the occlusal contact region without reconstruction of the mandibular bone was useful for the control of mandibular deviation to the affected side and improvement of the masticatory function.

The Role of Sonic Hedgehog Signaling in Osteoclastogenesis and Jaw Bone Destruction.

Sonic hedgehog (SHH) and its signaling have been identified in several human cancers, and increased levels of its expression appear to correlate with disease progression and metastasis. However, the role of SHH in bone destruction associated with oral squamous cell carcinomas is still unclear. In this study we analyzed SHH expression and the role played by SHH signaling in gingival carcinoma-induced jawbone destruction. From an analysis of surgically resected lower gingival squamous cell carcinoma mandible samples, we found that SHH was highly expressed in tumor cells that had invaded the bone matrix. On the other hand, the hedgehog receptor Patched and the signaling molecule Gli-2 were highly expressed in the osteoclasts and the progenitor cells. SHH stimulated osteoclast formation and pit formation in the presence of the receptor activator for nuclear factor-κB ligand (RANKL) in CD11b+ mouse bone marrow cells. SHH upregulated phosphorylation of ERK1/2 and p38 MAPK, NFATc1, tartrate-resistant acid phosphatase (TRAP), and Cathepsin K expression in RAW264.7 cells. Our results suggest that tumor-derived SHH stimulated the osteoclast formation and bone resorption in the tumor jawbone microenvironment.

Recurrent giant mandibular ameloblastoma in young adults.

BACKGROUND: The purpose of the study was to define the most appropriate management of the giant mandibular ameloblastoma (GMA) in young adults. METHODS: A retrospective study was performed on patients with GMA <30 years old. The data collected included initial treatment, tumor margins, reconstruction, and follow-up. Patients evaluated speech, chewing, swallowing, and facial appearance after definitive treatment. RESULTS: Thirteen patients were identified with recurrent solid/multicystic disease requiring further treatment. Definitive treatment involved segmental mandibulectomy and reconstruction with free fibular flap in all patients. Seven patients had immediate reconstruction (group A) and 6 had secondary (group B). Mandibular resection was planned at least 2 cm beyond the radiological limit, free margins were achieved in all patients, and all flaps were transplanted successfully. In group A, functional score was 13.7 ± 0.45 and facial appearance score was 4.5 ± 0.49, whereas in group B were 11.16 ± 0.37 and 3.3 ± 0.5, respectively (both p < .05). CONCLUSION: Aggressive resection of the GMA and immediate reconstruction is strongly advised. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1947-E1954, 2016.

Osteoma of the mandibular condyle: report of a case with 5-year follow-up.

Osteomas of the mandibular condyle are rare. An unusual case of an osteoma occurring in the mandibular condyle of a 22-year-old man with mandibular deviation and malocclusion is reported; this represents the 14th documented case in the English language literature. The tumor was resected with condylectomy. Postoperatively, mandibular deviation was minimized.

Evaluation of quality of life among patients after extirpation of mandibular ameloblastoma.

OBJECTIVE: To evaluate the quality of life (QOL) based on the functional, aesthetic and personal satisfaction among patients with ameloblastoma who underwent either partial or total mandibulectomy without reconstruction. DESIGN: Cross-sectional study. SETTING: The Department of Oral Surgery and Oral Pathology, School of Dentistry; Muhimbili University College of Health Sciences, Tanzania. SUBJECTS: Patients surgically treated for ameloblastoma without reconstruction. RESULTS. The postoperative problems were mostly associated with eating of solid foods, appearance and speech. All patients treated by total mandibulectomy had moderately severe problems with eating of solid foods and were dissatisfied with their appearance. CONCLUSION: The relatively small tumours resulted in a much better QOL. Public awareness programmes to avoid late referral and treatment is the most effective way to reduce the number of patients who after treatment suffer a poor QOL.

Evaluation of Masticatory Efficiency and QoL Improvements After Prosthetic Rehabilitation of Mandibular Cancer Patients Reconstructed with a Fibula Free Flap.

PURPOSE: The purpose of this noninferiority study was to determine whether removable or implant-supported fixed dental prostheses restored patients' abilities to preoperative levels after cancer removal in the mandible. MATERIALS AND METHODS: Ten patients who had undergone mandibular resection to remove cancer and subsequent reconstruction with microvascularized free fibula flaps were examined in this study. Five patients were rehabilitated with removable prostheses and five received implant-supported fixed prostheses. Health-related quality of life was evaluated using the Head and Neck (H&N30) questionnaire. Kruskal-Wallis nonparametric analysis of variance and Tamhane's T2 test were used to analyze results in comparison with a control group composed of 10 subjects with Class I natural dentition. RESULTS: Masticatory efficiency among the three groups of patients differed significantly (P=.003); in particular, that of the patients who received removable prostheses was not inferior to that of the control subjects (P=.019). Analysis of responses to the Head and Neck module of the Quality of Life Questionnaire showed no significant difference between patients with fixed dentures and patients with removable dentures. CONCLUSIONS: There is no apparent difference in quality of life between patients using implant-supported fixed prostheses and those using removable prostheses. Regarding masticatory efficiency, when feasible, the use of implant-supported fixed prostheses is recommended in patients who have undergone free fibula flap surgery, although the removable prostheses also were not inferior in patients who underwent no surgery.

Failure location prediction by finite element analysis for an additive manufactured mandible implant.

In order to reconstruct a patient with a bone defect in the mandible, a porous scaffold attached to a plate, both in a titanium alloy, was designed and manufactured using additive manufacturing. Regrettably, the implant fractured in vivo several months after surgery. The aim of this study was to investigate the failure of the implant and show a way of predicting the mechanical properties of the implant before surgery. All computed tomography data of the patient were preprocessed to remove metallic artefacts with metal deletion technique before mandible geometry reconstruction. The three-dimensional geometry of the patient's mandible was also reconstructed, and the implant was fixed to the bone model with screws in Mimics medical imaging software. A finite element model was established from the assembly of the mandible and the implant to study stresses developed during mastication. The stress distribution in the load-bearing plate was computed, and the location of main stress concentration in the plate was determined. Comparison between the fracture region and the location of the stress concentration shows that finite element analysis could serve as a tool for optimizing the design of mandible implants.

Mechanisms of cancer invasion of the mandible.

There is little evidence that the tumor enters the mandible preferentially through the occlusal surface, the periodontal membrane, or named foramina. Tumor enters the mandible at the point of contact, which is often at the junction of the attached and reflected mucosa, which lies below the crest of the ridge in all but grossly resorbed mandibles. Angulation of the bone cut in rim or marginal resection of the mandible is advised. The erosive pattern of disease is associated with shallow mandibular invasion and smaller tumors in the soft tissue. This finding supports the principle of marginal resection in such cases. There is little evidence to support the principle that the tumor spreads preferentially along the inferior alveolar nerve or the bone marrow. The inclusion of the neurovascular bundle in marginal resections of the mandible is not necessary. Preoperative assessment should include plain radiography combined with a sensitive scan (bone scintigraphy, single photon emission computerized tomography, or MRI) and inspection of the bone surface after periosteal stripping at the time of the resection.

Oral rehabilitation with implant-retained prostheses following ablative surgery and reconstruction with free flaps.

Ablative surgery of the oral tissues may result in significant facial deformity, poor oral function, and psychologic detriment. Immediate surgical reconstruction with vascularized free flaps has become increasingly popular, but the oral rehabilitation of these patients with conventional dental prostheses is usually unsuccessful. The results and clinical experiences of treating a group of 17 patients with ablative surgery, immediate reconstruction with free flaps, and restoration with mandibular implant-retained prostheses are presented after follow-up periods of 6 months to 7 years. Most patients expressed a high degree of satisfaction with their prostheses. General principles and guidelines for the provision of this effective treatment modality are discussed.

Microvascular free-tissue transfer with rigid internal fixation for reconstruction of the mandible following tumor resection.

The authors described their experience using rigid internal fixation techniques in combination with free microvascular tissue transfer for the immediate reconstruction of mandibular defects following tumor ablation. The technique allows immediate return of jaw motion and limited function while assuring maintenance of occlusion and reasonable cosmesis.

Ameloblastoma: a clinical, radiographic, and histopathologic analysis of 71 cases.

OBJECTIVES: The purpose of this study was to compare the clinical, radiologic, and histopathologic features of 71 intraosseous ameloblastomas. STUDY DESIGN: Data with respect to the patients' ages, sex, tumor locations, and surgical treatment history, as well as the radiographic findings and number of recurrences, were analyzed. The histologic types of and radiologic findings regarding tumors with higher recurrence rates were also investigated. RESULTS: The patients' ages at biopsy ranged from 11 to 70 years (mean, 30.4 years). Thirty-nine (54.9%) of the 71 subjects were males, and 32 (45.1%) were females. Sixty-two (87.3%) of the 71 ameloblastomas were located in the mandible. Swelling was the most common symptom and was experienced by 27 (38.0%) patients. Radiographically, 42 (59.2%) of the 71 tumors were unilocular with a well-demarcated border. Of the remaining 29 cases, 14 were multilocular, 2 were of soap-bubble shape, and 13 were unknown in appearance. The most common histologic pattern was plexiform, rather than follicular or acanthomatous. Sixteen cases of ameloblastoma had developed in a cyst. The overall recurrence rate was 21.1%, and the average age of the patient at recurrence was 26.4 years. CONCLUSIONS: When the diagnosis of ameloblastoma in young people remains in doubt after clinical and radiologic examination, a biopsy is necessary. Long-term follow-up at regular intervals after surgery is also recommended.

Osteochondroma of the mandibular condyle. Report of a case and review of the literature.

Osteochondroma (osteocartilaginous exostosis) is a rare tumour in the region of the mandibular condyle. Much confusion seems to exist in the literature in differentiating these tumours from condylar chondromas as well as from condylar hyperplasias. A case of condylar osteochondroma with a review of the literature is presented.

Hypercalcaemia and the synthesis of interleukin-1 by an ameloblastoma.

A case of hypercalcaemia secondary to a long-standing solitary ameloblastoma is presented with evidence to suggest that the raised plasma calcium was the result of the secretion of interleukin-1 and a parathyroid hormone-like substances by the tumour. The aetiology of humoral hypercalcaemia of malignancy is discussed in relation to the role played by these substances.