Can calcitonin nasal spray reduce the risk of recurrence of central giant cell granuloma of the jaws? A double-blind clinical trial.

Recurrence is a major problem following the treatment of aggressive central giant cell granuloma (CGCG). The aim of this study was to compare the frequency of recurrence between patients who received calcitonin nasal spray after curettage of CGCGs and those who did not. A double-blind clinical trial was designed. Patients were allocated to one of two groups: those in the calcitonin group underwent curettage and received calcitonin salmon nasal spray 200IU/day once a day for 3 months after surgery; those in the control group underwent curettage of CGCGs and received a placebo once a day for 3 months after surgery. All patients were followed for 5 years after surgery. Twenty-four patients were treated in the two groups. There was no difference in age, sex, tumour size, or tumour location between the two groups (P>0.05). Eight of the 24 patients (33.3%) had recurrences during the follow-up period: one in the calcitonin group (9.1%) and seven in the control group (53.8%). Analysis of the data demonstrated a significant difference between the two study groups (P=0.033). It appears that calcitonin nasal spray may reduce the frequency of recurrence in aggressive CGCGs in the mandible and maxilla.

Medial cortex fracture patterns after sagittal split osteotomy using short versus long medial cuts: can we obviate bad splits?

The aim of the present study was to evaluate the lingual fracture patterns after sagittal split osteotomy (SSO) using short and long medial osteotomy cuts, via three-dimensional (3D) cone beam computed tomography (CBCT). Forty-six subjects participated in this prospective study. Two types of medial osteotomy line were made: for type I, the medial osteotomy line was finished just before the lingula; for type II, the medial osteotomy line was extended 3-4mm beyond the lingula. Three fracture patterns were observed after SSOs. There were no significant differences in the medial fracture patterns between the two medial osteotomy types (P=0.16). The buccolingual thickness of the ramus was lower in fractures with pattern 3 (bad split) than in the two other fracture patterns. The length of the medial osteotomy line - short or long - did not alter the prevalence of a bad split. The bone thickness of the ramus may affect the type of fracture pattern on the medial side of the ramus.

Effect of magnetic resonance imaging on microleakage of amalgam restorations: an in vitro study.

OBJECTIVES: The technique of MRI, using powerful magnets, plays an important role in the diagnosis of diseases of the head and neck without any ionizing radiation. Because of the potential hazard imposed by the presence of ferromagnetic metals, patients with implanted metallic objects are excluded from MRI. However, amalgam restorations seem to be safe. The purpose of this study was to evaluate microleakage of amalgam restorations following MRI. METHODS: 63 human freshly extracted premolars were divided into 3 groups based on 3 high-copper amalgams used to restore standard class V preparations on both buccal and lingual surfaces. Three different amalgam materials were used: Cinalux, GS-80 and Vivacap. The teeth were transferred into saline solution for 2 months at room temperature and then sectioned mesiodistally. MRI was randomly applied to one half of each section, and the other half was kept as a control. Following MRI, all specimens were immersed in a dye solution, sectioned and scored for any microleakage using a stereomicroscope. RESULTS: Differences in microleakage within each group following MRI were significant in the GS-80 and Vivacap groups but not in the Cinalux group. However, there was no significant difference between the three groups regarding the microleakage score. CONCLUSIONS: The results of this study suggest that MRI is not a completely safe technique in patients with amalgam restorations. It was shown that the main effect of fields led to the appearance of thermoelectromagnetic convection, which is responsible for the enhancement of the diffusion process, grain boundary migration and vacancy formation resulting in microleakage.

Anchorage value of surgical titanium screws in orthodontic tooth movement.

The aim of this study was to evaluate the clinical stability and anchorage value of titanium screws in orthodontic tooth movement. Nine patients, who needed maximum anchorage for canine retraction, were selected. Records of 10 patients with similar malocclusions who had received conventional treatment were used as controls. In the maxilla and mandible 27 mini-screws, diameter 2mm and length 9 or 11 mm, were used. At the end of the first stage of orthodontic treatment the first premolar teeth were extracted after taking a lateral cephalometric radiograph. After 1 week, a retraction force of 180 g was applied to the canines. The second cephalometric X-rays were taken and evaluated after the completion of canine retraction (mean duration of 23.2 weeks). Results were analysed using Fisher Exact, Wilcoxon signed ranks and paired t-tests. Displacement of the first molars and screws before and after treatment showed no significant changes in either the vertical or horizontal plane. The first molar movements in the study and control groups were only significant in the antero-posterior plane in both maxilla and mandible. Of the 9 screws in maxilla and 18 screws in mandible, 2 and 3 screws showed clinical failure, respectively. The failed screws were replaced by other screws that withstood the applied force until the end of treatment. In conclusion, titanium screws can be used reliably as a form of anchorage.