In vitro biomechanical evaluation of the use of conventional and locking miniplate/screw systems for sagittal split ramus osteotomy.

PURPOSE: The aim of this in vitro study was to assess the biomechanical stability of 9 different osteosynthesis methods after sagittal split ramus osteotomy by simulating the masticatory forces and using a 3-point biomechanical test method. MATERIALS AND METHODS: Forty-five polyurethane hemimandibles with bone-like consistency were randomly assigned to 9 groups (n = 5) and subjected to sagittal split ramus osteotomy. After 4-mm advancement of the distal segment, the bone segments were fixed by different osteosynthesis methods using 2.0-mm miniplate/screw systems: group A, one 4-hole conventional straight miniplate; group B, one 4-hole locking straight miniplate; group C, one 4-hole conventional miniplate and one bicortical screw; group D, one 4-hole locking miniplate and 1 bicortical screw; group E, one 6-hole conventional straight miniplate; group F, one 6-hole locking straight miniplate; group G: two 4-hole conventional straight miniplates; group H, two 4-hole locking straight miniplates; and group I, 3 bicortical screws in an inverted-L pattern. All models were mounted on a base especially constructed for this purpose. Using a 3-point biomechanical test model, the hemimandibles were loaded in compressive strength in an Instron machine (Norwood, MA) until a 3-mm displacement occurred between segments vertically or horizontally. Data were analyzed by analysis of variance and Tukey test (alpha = 1%). RESULTS: The multiparametric comparison of the groups showed a statistically significant difference (P < .01) between groups that used 2 miniplates (groups G and H), 1 miniplate and 1 bicortical screw (groups C and D), and only bicortical screws (group I) compared with groups that used only 1 miniplate with 2 screws per segment (groups A and B) and 3 screws per segment (groups E and F). CONCLUSION: The placement of 2.0-mm-diameter bicortical screws in the retromolar region, associated or not with conventional and locking miniplates with monocortical screws, promoted a better stabilization of bone segments. Locking miniplates presented a better performance in bone fixation in all groups.

A clinico-pathologic correlation: primary Ewing's sarcoma of the mandibular body-ramus.

A 15-year-old Asian male was referred to the department of oral and maxillofacial surgery at Tufts University School of Dental Medicine (TUSDM) for evaluation of a radiolucent lesion on the posterior left mandible. The patient was initially evaluated by his primary dentist for pain of two months' duration associated with teeth #17 and 18. Radiographic examination was performed and the panoramic radiograph revealed a radiolucent lesion involving the left mandibular body and ascending ramus, along with resorption of the roots of the predetermined teeth. Considering odontogenic infection, the patient was placed on antibiotics and referred to TUSDM for further evaluation and treatment.

Etiology of oral cancer in the young patient: is tongue cancer becoming the other cancer in women?

The recently reported increase in the incidence of oral cancer in a younger population, especially in young women, in the absence of the traditional risk factors has raised concern. Of particular interest is the increased incidence of carcinoma of the tongue, which has been suggested to be a distinct entity. Although there are conflicting data on incidence and sex distribution, studies suggest that the physiologic response to risk factors by men and women and the clinical behavior of these cancers in the younger population may be different than the normal variant. Effort is currently being made to elucidate the etiology and pathogenesis of oral cancer in the younger population.

Distraction osteogenesis for augmentation of the deficient alveolar ridge.

Distraction osteogenesis is a technique in which new bone generation and soft tissue proliferation are achieved by means of distraction or lengthening of the preexisting native bone. This technique has its origins in orthopedic surgery and has been used more extensively in the craniofacial region over the past few years. It has been successfully used to treat patients with mandibular, maxillary, and midface deficiencies, and its use for augmentation of the resorbed or atrophic dento-alveolar ridge is currently being explored. In this report, the technique of alveolar distraction is discussed and two cases are presented in detail.

Mandibular sarcoidosis: case presentation.

Oral and maxillofacial sarcoidosis is rare. Although the systemic effects and course of the disease are well described, the etiology of sarcoidosis remains unknown. Diagnosis involves histologic, radiographic, and clinical correlation, and laboratory tests can be used to monitor disease activity. Treatment is directed at suppression of the immune system, and communication among members of the healthcare team is important for successful therapy.