Static bone cavity in the condylar neck and mandibular notch of the mandible

This study presents the radiographic findings of two cases of static bone cavity in the inferior aspect of the condylar neck and mandibular notch of the mandible. On plain CT, a soft tissue mass was observed in each cavity. The submandibular gland and the other glands were not found in each cavity. On contrast-enhanced CT, the soft tissue in the cavity in the inferior aspect of the condylar neck had marked linear enhancement and dilated vasculature structure was observed in the cavity. On the contrast-enhanced MRI, the soft tissue in the cavity of the mandibular notch had marked enhancement and flow void was detected in the cavity. In the inferior aspect of the condylar neck, the cavity size had enlarged radiographically over a period of three years. Vascular lesions were found in the cavity located in the inferior aspect of the condylar neck and mandibular notch of the mandible by both CT and MRI. The vascular lesion might explain the enlargement of the static bone cavity.     

Mucinous adenocarcinoma with neuroendocrine differentiation of the mandibular ramus: report of a case

A rare case of mucinous adenocarcinoma with neuroendocrine differentiation of the mandibular ramus is presented. The patient, an 80-year-old man, was referred to our hospital with chief complaint of swelling and pain in the left buccal mucosa. CT and MRI examination showed an osteolytic tumor mass occupying the upper region of the left mandibular ramus. Macroscopically, the excised tumor was a relatively well-defined, solid mass with diffuse bone resorption, measuring 3 cm x 3.2 cm x 3 cm. Microscopical examination showed that the tumor forming glandular structures with abundant mucous production and high cellular atypia. Immunohistochemical studies demonstrated the positive reactivities for pan-keratin, cytokeratin 7, vimentin,alpha-amylase, alpha-smooth muscle actin, neuron-specific enolase, glial fibrillary acid protein, calcitonin, and somatostatin in tumor cells. These findings suggested that the tumor was originated from heterotopic or misplaced salivary gland in the mandible.     

Unusual healing of apical root fracture

A 23-yr-old woman received a blow to the symphysis region of the mandible. She sustained several injuries including a root fracture of the mandibular left lateral incisor. The pulp in the coronal root portion of that tooth became necrotic. A radiolucent lesion developed at the apex of the coronal root portion, and the apical root fragment was displaced 2 1/2 mm. Following endodontic treatment of the coronal segment, the apical fragment returned to its original position.     

Effect of mandibular positioning on preimplant site measurement of the mandible in reformatted CT

The purpose of this study was to evaluate the effect of mandibular positioning on measurement of the reformatted cross-sectional image of the mandible in computed tomography (CT) according to the area on the mandible. Five dried mandibles, partially edentulous in the premolar and molar areas, were selected. The inferior border of the mandible was placed at 0-, 5-, 10-, 15-, and 20-degree angles to the CT scanning plane, and CTs were taken. The marked area of the reformatted cross-sectional image taken at each angle was found, and the distance from the most superior border of the mandibular canal to the alveolar crest was measured. As the angle between the CT scanning plane and mandibular plane increased, the distance from the most superior border of the mandibular canal to the alveolar crest also increased. The degree of increase was more pronounced in the posterior portion of the mandible than in the anterior portion of the mandible. As mandibular positional change in the CT gantry can affect the vertical measurement of the reformatted cross-sectional image, a correct guiding plane is necessary to accurately position the jaw to the CT scanning plane.     

Monostotic fibrous dysplasia with involvement of the mandibular canal

A 72-year-old woman sought treatment with a rare monostotic fibrous dysplasia occurring in the mandible and involving the mandibular canal. Her chief complaint was swelling, which had appeared about 2 years previously, had enlarged gradually, and was associated with spontaneous pain. X-ray film examination revealed a ground-glass opaque image of blurred demarcation, and 99mTc-methylene diphosphonate bone scintigraphy disclosed an area of marked radioisotope uptake. Histopathologic examination revealed the area of bone marrow and spongy bone to be replaced by fibrous tissue, irregular beam-shaped woven bone, and lamellar bone. Contouring of the expanded portion of the bone and surgical decompression of the mandibular canal were performed with good results.     

Benign fibrous histiocytoma in the mandible

PURPOSE: Benign fibrous histiocytoma (BFH) is a very rare benign tumor occurring in the jaw. The purpose of this article is to describe the clinical, radiographic, and microscopic appearance of BFH occurring in the mandible. STUDY DESIGN: A 42-year-old man had an asymptomatic swelling of the left mandibular posterior area. RESULTS: Conventional radiographs revealed a well-defined multilocular radiolucency involving the left mandibular body, ramus, coronoid process, and condylar head. The lesion showed the thinning and expansion of the cortex. There were many thin, indistinct septa in the lesion. The computed tomography (CT) scans showed bone destruction with marginal sclerosis and a heterogeneous soft-tissue mass expanding the mandible. Microscopic examination revealed a cellular tumor composed of uniform spindle-shaped cells arranged in a storiform pattern. CONCLUSIONS: BFH is a very rare benign tumor occurring in the jaw, so more cases should be reported to understand the characteristics of the lesion.     

Autoradiographic evaluation of 99mTc-methylene diphosphonate accumulation in oral cancer invading the mandible.

PURPOSE: Skeletal scintigraphy, a sensitive diagnostic tool used to detect changes in bone, is helpful for evaluating bone invasion by oral cancer. However, the exact sites of accumulation of 99mTc-phosphate compounds in the mandible have not yet been fully elucidated. The aim of this study was to determine the localization of 99mTc-methylene diphosphonate (MDP) in the areas of mandible that have been invaded by cancer. PATIENTS AND METHODS: Seven patients with oral cancer (lower gingiva, 4; tongue, 2; floor of the mouth, 1) who underwent surgical treatment with mandibular bone resection were included in the study. Autoradiography and contact macroradiography were used for evaluation of 99mTc-MDP accumulation. RESULTS: Radioactivity reflecting accumulation of 99mTc-MDP was documented encircling the portion of the mandible with cancerous invasion, suggesting that 99mTc-MDP accumulated in immature bone. High uptake also was found in the periosteal reactive bone around the cortical bone. CONCLUSIONS: The amount of increased 99mTc-MDP circumscribing carcinoma invasion varies among cases. Additionally, uptake may not correspond directly with the amount of the carcinoma invasion; that seen in periosteal bone could be attributed mistakenly to bone invasion in planar scintigraphy.     

A comparison of different imaging modalities and direct inspection after periosteal stripping in predicting the invasion of the mandible by oral squamous cell carcinoma

Objective—To compare the predictability of orthopantomograms (OPG), bone scans, computerised tomography (CT), magnetic resonance imaging (MRI) and periosteal stripping with direct inspection in predicting both the presence and extent of tumour invasion of the mandible.Design—Prospective study.Setting—Queen Elizabeth Hospital, Birmingham; Wordsley Hospital, Stourbridge; North Staffordshire Royal Infirmary, Stoke-on-Trent.Subjects—35 consecutive patients requiring a mandibular resection as part of their treatment for oral squamous cell carcinoma.Main outcome measures—The prediction of the extent of bone invasion for each of the investigations and direct inspection after periosteal stripping. The actual extent of invasion of the mandible from a detailed histological assessment.Results—The OPG underpredicted the width and depth of invasion by on average 13 mm and 2 mm. There were 5 false negative reports. Bone scans overpredicted the width and depth by 14 mm and 15 mm with 1 false negative. CT scans underpredicted the width of invasion by 5 mm and overpredicted depth by 3 mm, but 7 false negatives were returned. MRI scans overpredicted width and depth of invasion by 19 mm and 10 mm with 1 false negative. Direct inspection after periosteal stripping underpredicted the width and depth of invasion by 5 mm and 3 mm with 1 false negative.Conclusion—OPG's and bone scans are useful for the initial assessment of all tumours in the region of the mandible. MRI is a more useful investigation than CT in the assessment of mandibular invasion by oral squamous cell carcinomas. Exploratory periosteal stripping at the time of resection can accurately predict the presence of tumour invading the mandible.     

Langerhans cell histiocytosis in the mandible: Computed tomography and magnetic resonance imaging

Langerhans cell histiocytosis in the mandible is a rare disease. The clinical and advanced imaging features of Langerhans cell histiocytosis in an 18-year-old male are presented. CT images showed an diffuse, ill-defined, expansile lesion of heterogeneous density extending from the anterior mandibular area to the right molar area. CT was particularly helpful in confirming a cortical invasion. T1-weighted gradient echo MR images revealed a heterogeneously low-to high-signal intensity lesion in the right side of the mandible. T2-weighted spin echo MR images showed a heterogeneously iso-to high-signal intensity area with low-intensity areas. Multidirectional MR images revealed the extent of the lesion in the mandibular bone marrow more clearly than CT.     

A case of sublingual adenoid cystic carcinoma involving the mandible presenting as a “skip lesion”

Adenoid cystic carcinoma (ACC) is a slowly growing malignant neoplasm with a propensity for perineural invasion. Microscopic invasion of ACC often prevents its detection on computed tomography (CT) or magnetic resonance imaging (MRI). We herein report a rare case of sublingual ACC presenting as a “skip lesion” that rapidly infiltrated the mandible after tumor resection. A 64-year-old man presented to Okayama University Hospital with an 18-month history of swelling in the right floor of the mouth. Clinical examination displayed an ulcerated swollen mass in that region. An enhanced mass was detected in the right sublingual space on CT and MRI. Bone surface erosion was observed at the inferior border of the mandible, but continuity with the sublingual mass or mass around that lesion was not detected by imaging. Sublingual tumor resection and selective neck dissection were performed by the pull-through method. Histopathologically, the surgical margins were free of cancer cells, and the tumor was diagnosed as ACC. Continuity with the sublingual mass and mandibular bone was not detected intraoperatively. However, marked bone resorption was detected in the anterior mandible 3 months after the operation. Biopsy was performed, and the findings indicated the same histological type of sublingual ACC. This case suggests that a malignant tumor close to the jaw bone requires the clinician to consider the possibility of bone invasion and to observe a wide region surrounding the tumor using imaging examination.     

Vertical distraction osteogenesis of fibular free flap in mandibular prosthetic rehabilitation: a case report

A 17-year-old boy underwent three cycles of chemotherapy and a subsequent mandibular resection for a Ewing's sarcoma of the left body and ramus. The mandible was immediately reconstructed with a microvascular osteomuscular fibular flap. One year after the mandibular reconstruction, distraction osteogenesis of the anterior portion of the fibula was performed using a Martin distractor according to the Hoffmeister technique. Bone lengthening was achieved at a rate of 1 mm/day by turning the device twice each day for 12 days. Subsequently, we waited for 70 days for bone consolidation to occur. After 6 additional weeks, five Maestro implants were placed into the distracted fibula. Bone specimens were retrieved with a trephine bur during implant placement. Mature bone was present after 70 days and after 6 months. The bone height increase was 12 mm.     

Mandibular metastases as first clinical sign of an occult male breast cancer

A 73-year-old man presented with a painful swelling of the left temporomandibular joint with no other symptoms. Panoramic radiography showed an osteolytic lesion in the left mandibular body, while magnetic resonance imaging provided the most accurate view of an osteolytic lesion in the left condyle. Skeletal scintigraphy showed increased uptake in the mandibular anatomical area. A diagnosis of metastatic breast adenocarcinoma was made from mandibular biopsies which proved to be ductal carcinoma, with no evidence of any other metastases. Clinicopathologic features of this case are reviewed.     

Follicular/desmoplastic hybrid ameloblastoma with radiographic features of concomitant fibro-osseous and solitary cystic lesions

We report a case of ameloblastoma radiographically suggestive of a complication of fibro-osseous and solitary cystic lesions. A 35-year-old woman was referred to our hospital for treatment, complaining of swelling in the left premolar region of the mandible. Radiological findings indicated a mixed radiopaque and radiolucent lesion in the region of the left mandibular canine and first premolar as well as a solitary cystic lesion in the mandibular second premolar region. Following biopsy, resection of mandible was performed under general anesthesia. Histopathologic examination identified follicular-type ameloblastoma with partial desmoplastic findings. Conventional radiography and computed tomography were not useful in indicating the relationship between the mixed and solitary cystic lesions. However, magnetic resonance imaging was instrumental in elucidating this relationship.     

发育性不对称畸形下颌骨生长活性的核素显像研究

目的:研究下颌骨发育性不对称畸形患者髁突、下颌升支及下颌体生长活性的特征,为该类畸形患者手术时机及手术方案的选择提供参考。方法:对29例下颌骨发育性不对称畸形患者进行了下颌骨各部位99mTc-MDP吸收状况的测定,并以患者自身第4腰椎的吸收值作为参考以排除个体间差异。将病例分为大年龄组(≥20岁)和小年龄组(<20岁),其中大年龄组13例,小年龄组16例。对下颌骨髁突、升支、下颌体各部位的99mTc-MDP吸收比值进行统计学分析。结果:大年龄组下颌骨各区的吸收比值双侧无显著差异,个别患者在20岁以后仍显示出畸形区活跃的生长活性;小年龄组双侧髁突区吸收比值差异显著(P<0.05);检测结果显示下颌骨发育不良侧与正常侧无显著差异;而发育过度侧与正常侧及发育不良侧的差异显著。结论:在20岁以前发育性下颌骨不对称畸形大部分处于快速发展阶段,20岁以后趋于平稳;少数病例在20岁以后其畸形的下颌骨在髁突区仍有活跃生长的现象。下颌骨不对称畸形的手术治疗,术前可以通过核素显像检查确定非正常发育是否停止来决定手术时机的选择。     

Aneurysmal bone cyst of the mandible managed by conservative surgical therapy with preoperative embolization

A 9-year-old girl visited our hospital, complaining of a rapid-growing and rigid swelling on the left posterior mandibular area. Panoramic radiograph showed a moderately defined multilocular honeycomb appearance involving the left mandibular body. CT scan revealed an expansile, multilocular osteolytic lesion and multiple fluid levels within cystic spaces. Bone scan demonstrated increased radiotracer uptake and angiography showed a highly vascularized lesion. The lesion was suspected as aneurysmal bone cyst (ABC) and preoperative embolization was performed, which minimize the extent of operation and the surgical complication. The lesion was treated by surgical curettage and lateral decortication with repositioning. No additional treatment such as a surgical reconstruction or bone graft was needed. Early diagnosis of ABC is very important and appropriate treatment should be performed considering several factors such as age, surgical complication, and possibility of recurrence.     

颞下颌关节弥漫型腱鞘巨细胞瘤的CT影像特征

目的 探讨颞下颌关节弥漫型腱鞘巨细胞瘤CT影像的特征性表现,提高对该疾病的认识及影像诊断能力。方法 回顾性分析北京大学口腔医院2013年3月—2017年3月收治的10例经手术及病理诊断为颞下颌关节弥漫型腱鞘巨细胞瘤患者的CT表现及临床资料。结果 10例患者均表现为高密度软组织肿块伴不同程度钙化,6例患者的增强扫描影像均表现为显著强化,7例患者出现髁突骨质吸收或破坏,6例患者伴有颅底骨质破坏。结论 颞下颌关节弥漫型腱鞘巨细胞瘤的CT特征表现为高密度软组织肿块伴钙化和显著强化,可伴有髁突和颅底骨质的吸收或破坏。     

富血小板血浆对骨移植后颌骨缺损愈合早期骨代谢活性的影响

目的：探讨富血小板血浆对颌骨缺损愈合早期骨代谢活性的影响.方法：拔除5只狗双侧下颌第一磨牙后扩大牙槽窝，形成骨缺损模型。实验侧植入Osteoset和富血小板血浆，对照侧植入Osteoset。术后2、4、6周对缺损区进行^99m锝骨显像定量测定缺损区新骨生成代谢活性。结果：各缺损区均呈现放射性核素浓集区，并在第4周达到高峰。实验组与对照组仅在第2周放射性计数有显著性差异，而在第4、6周没有显著性差异。结论：富血小板血浆可促进骨移植后颌骨缺损愈合骨代谢活性，其效应在术后早期表现出来。     

Radiographic features of a patient with both cemento-ossifying fibroma and keratocystic odontogenic tumor in the mandible: a case report and review of literature

We herein describe a rare case of a 48-year-old woman with both ossifying fibroma (OF) and keratocystic odontogenic tumor (KCOT) in the mandible. CT images showed a 15 × 15 × 20-mm radiolucent-radiopaque lesion with bucco-lingual bony expansion in the left first premolar equivalent area of the mandible, and a 15 × 40 × 35-mm well-defined unilocular radiolucent lesion in the left side of the mandible, extending from the distal side of the distal root of the left second molar to the left mandibular ramus. A biopsy of the radiolucent-radiopaque lesion and fenestration surgery of the radiolucent lesion were performed. Histopathologic examination revealed a fibro-osseous lesion (FOL) and a KCOT, respectively. CT was useful in diagnosing the radiolucent-radiopaque lesion as OF and for detecting the 3-dimensional bone expansion and the contents in the lumen of the KCOT.     

Sequential second free fibula flap for the reconstruction of metachronous osteoradionecrosis of the mandible

Osteoradionecrosis (ORN) of the mandible is a potentially catastrophic complication of external beam radiation therapy for head and neck malignancies. A 55-year-old man treated with chemoradiation for base-of-tongue cancer presented with a necrotic left mandibular body and underwent left mandibulectomy with right free fibula osteocutaneous flap reconstruction. Two and a half years later, he presented with right mandibular body ORN and underwent a second mandibular resection and subsequent reconstruction with a left fibula osteocutaneous free flap fixed in the midline to the previously placed contralateral fibula. He recovered well from all procedures. To the best of our knowledge, we report the first case of a patient with metachronous ORN of the mandible requiring resection and subsequent reconstruction with sequential free fibula flaps. Even in the presence of prior microvascular reconstructions, patients can successfully undergo additional reconstructive procedures to restore their function, appearance, and quality of life.