orthodontic adhesive system was used, along with placement of a 0.014-inch nickel-titanium arch wire for leveling. The brackets were relocated further gingivally and occlusal reduction was performed so the teeth could be extruded. Progress was monitored every 2 weeks, with the occlusal surface of the extruding teeth reduced at each of these appointments. Further movement gingivally was accomplished after 8 weeks of orthodontic extrusion. Metal brackets were then bonded to the mandibular teeth to permit the use of intermaxillary vertical elastics and avoid crowding of the maxillary arch. Three months after orthodontic treatment began, stainless steel arch wires with step-down bends were placed on the extruding teeth. The patient was then instructed to wear intermaxillary elastics with vertical components on the right side. Light elastics were chosen to avoid excessive bone or root resorption of the anchoring teeth. The mandibular arch leveling was complete and the brackets removed after 7 months of orthodontic therapy. Significant extrusion of the maxillary first premolar and first and second molars had been accomplished. Interdental stripping and protrusion of the mandibular incisors completed the elimination of mandibular anterior arch crowding. Bonded fiber-reinforced retainers were applied to both arches to achieve retention.
supported FPDs. On radiographs and intraoral examination, the patient demonstrated substantial hard tissue regeneration at the recipient sites (Fig 4).
The remaining roots were extracted and 2 dental implants were placed in the extraction sites of the first premolar and first molar. After 4 months, impressions of the implants were made to permit fabrication of the implant-
Reprints available from S Erkut, Baskent Univ, Faculty of Dentistry, Dept of Prosthodontics, Bahcelievler 11, sokak no 27 06490, Bahcelievler, Ankara, Turkey; fax: 90 312 215 29 62; e-mail: selim@ baskent.edu.tr
Discussion.—The use of forced eruption can develop an implant site that initially has too little bone and soft tissue to support the implant. The patient reported had advanced periodontal disease but responded well to the nonsurgical approach to prepare the implant site followed by the use of an implant-supported FPD.
Clinical Significance.—Confronted with insufficient bone for implant placement the clinician can choose from several grafting options, as well as distraction osteogenesis, to increase the available bone mass. Presented is the use of light wire, forced eruption to create sufficient alveolar bone to receive an implant.
Erkut S, Arman A, Gulsahi A, et al: Forced eruption and implant treatment in posterior maxilla: A clinical report. J Prosthet Dent 97:70-74, 2007
Oral and Maxillofacial Pathology Mandibular chondrosarcoma Background.—Rarely do chondrosarcomas affect the maxillofacial area. These malignant mesenchymal tumors demonstrate cartilaginous differentiation and, when seen in the maxillofacial region, usually arise from the maxilla, although a few arise from the mandible. Most patients are older than age 50, although chondrosarcoma can occur in patients of any age. Usually there is a painless mass or swelling associated with loose teeth. A patient with chondrosarcoma of the anterior mandibular region was reported. Case Report.—Woman, 43, was referred for swelling over the lingual aspect of the anterior mandible present for 2 years and slowly increasing. No history of trauma or pain was reported, although the patient had difficulty swallowing solid foods. No obvious facial swelling or asymmetry, cervical lymphadenopathy, or disorders of the cranial nerves were detected. Intraorally there was an indurated, painless, discoid swelling measuring 2.5 cm x 2.0 cm in the midline of the anterior mandible between the lower
26
Dental Abstracts
incisors and the sublingual duct opening. Confluent with the anterior margin of the swelling was the lower alveolus. Radiographs showed a radiolucent lesion with diffuse margins that had displaced the central incisor roots (Fig 1). The cortex had thinned, with evidence of cortical breakage (Fig 3). Chondrocytes in lacunae arranged in lobular patterns were noted histopathologically. Some areas showed infiltration into the mesenchymal tissue overlying them. A few cells demonstrated mitosis. The tumor was determined to be a low-grade chondrosarcoma. Segmental mandibulectomy was performed from the right first premolar to the left first premolar. Reconstruction was achieved using a free vascularized fibula flap. The diagnosis was confirmed on histopathologic evaluation of the specimen. The left mandibular margin was also positive for tumor, for which the patient received radiotherapy. No evidence of tumor remained after 12 months.
Fig 1.—Occlusal radiograph showing radiolucent area in the midmandibular region that has caused displacement of the roots of the central incisors. (Courtesy of Saini R, Razak NHA, Rahman SA, et al: Chondrosarcoma of the mandible. A case report. J Can Dent Assoc 73:175-178, 2007.)
Discussion.—Chondrosarcoma of the oral cavity normally affects the anterior maxilla, where there is preexisting nasal cartilage. The tumor is usually seen as a swollen area that is painful and causes loosening of adjacent teeth and widening of the periodontal ligament space. When the jaw is affected, chondrosarcoma may resemble periodontal lesions. The differentiation between benign and malignant lesions is based on clinical findings, including the loss of nerve sensation and dysesthesia. Even apparently benign chondrogenic tumors of the jaws should be considered malignant until evidence of their benign nature is forthcoming. No radiographic findings specifically identify chondrosarcoma, but single or multiple radiolucent areas with poorly defined borders are commonly noted on plain films. Among the entities to be included in the differential diagnosis are lateral periodontal cyst, early cemento-osseous dysplasia, central giant-cell granuloma, cemento-osseous fibroma, odontogenic cysts such as radicular or odontogenic keratocysts, odontogenic tumors, and other nonodontogenic lesions. The radiologic findings are similar in such painful lesions as osteomyelitis, periapical lesions, osteosarcoma, and Langerhans’ cell disease. Dentists should be aware of the wide range of presentations possible with chondrosarcomas. The prognosis is tied to the histologic grade, with grade I lesions resembling benign cartilage; grade II lesions having occasional mitotic figures and recurring more often than grade I lesions; and grade III lesions being more cellular and pleomorphic. Grade III lesions also have a marked increase in the number of mitotic figures present, with a rate of metastasis of 70%. Five-year survival is about 90%, 81%, and 43% for grade I, II, and III lesions, respectively. Treatment is wide surgical excision of all involved structures. Ideally the margins should be negative and function should be preserved. Radical surgery may be needed for more advanced lesions. Obtaining negative
Fig 3.—Three-dimensional image showing bone resorption at the midmandibular region. (Courtesy of Saini R, Razak NHA, Rahman SA, et al: Chondrosarcoma of the mandible. A case report. J Can Dent Assoc 73:175-178, 2007.)
margins is extremely important with higher grade lesions, because the lesion is readily implanted in soft tissue and then grows rapidly and invasively. Generally chondrosarcoma has been considered radioresistant, with radiotherapy reserved for lesions that are higher grade and surgically unresectable. The prognosis for these tumors depends most significantly on the tumor grade and resectability. Clinical Significance.—Uncommon in the maxillofacial region, chondrosarcoma of the mandible is even less common. Presented is a report of 1 such occurrence, as well as an extensive list of suggestions to consider in the differential diagnosis.
Saini R, Razak NHA, Rahman SA, et al: Chondrosarcoma of the mandible. A case report. J Can Dent Assoc 73:175-178, 2007 Reprints available from R Saini, School of Dental Sciences, Universiti Sains Malaysia, Health Campus, 16150, Kubang Kerian, Kelantan, Malaysia; e-mail:
[email protected]
Volume 53
Issue 1
2008
27