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Facial fractures often result in changes of the orbital volume. These changes can be measured in three-dimensional (3D) computed tomography (CT) scans for preoperative planning and postoperative evaluation. The aim of this study was to analyze the orbital volume and shape before and after surgical treatment of unilateral orbital fractures using semi-automatic image segmentation and registration techniques. The orbital volume in 21 patients was assessed by a semi-automatic model-based segmentation method. The fractured orbit was compared relative to the contralateral orbit. The same procedure was performed for the postoperative evaluation. Two observers performed the segmentation procedure, and the inter- and intraobserver variability was evaluated. The interobserver variability (mean volume difference ± 1.96 SD) was -0.6 ± 1.0 ml in the first trial and 0.7 ± 0.8 ml in the second trial. The intra-observer variability was -0.2 ± 0.7 ml for the first observer and 1.1 ± 0.9 ml for the second observer. The average volume overlap (Dice similarity coefficient) between the fractured and contralateral side increased after surgery, while the mean and maximum surface distance decreased, indicating that the surgery contributed to a re-establishment of size and shape. In conclusion, our study shows that the semi-automatic segmentation method has precision for detecting volume differences down to 1.0 ml. The combination of semi-automatic segmentation and 3D shape analysis provides a powerful tool for planning and evaluating treatment of orbital fractures.

Snus (Swedish moist snuff) causes lesions in the oral mucosa at the location where pinches are regularly placed. In addition, some patients develop irreversible local gingival recession and sometimes ulcers with perforations to the roots. Such injuries lead to denuded roots that are at risk for caries and periodontal disease, with subsequent esthetic consequences. Therapy for irreversible local gingival recession is currently lacking. In the present report, we describe two cases of successful surgical treatment for irreversible lesions caused by snus.

Trauma to the oral structures sometimes occurs as a complication to general anaesthesia. We here report two cases of an unusual type, mandibular osteonecrosis. To our knowledge, there has been only...

Mandibular Bone Exposure and Osteonecrosis in a Patient With an Uncomplicated Medical History

Over recent decades there has been debate over whether or not Swedish snuff is carcinogenic in humans. Animal studies and molecular biological and experimental studies have shown the carcinogenic potential of Swedish snuff, but this has not been proved in prospective randomized studies. We present a case series of patients with oral squamous cell carcinomas diagnosed at the sites where the patients had used Swedish snuff for several years. Sixteen male patients were referred to and treated at Oral and Maxillofacial Surgery Departments and Ear, Nose and Throat clinics at seven different hospitals in Sweden. The mean age of the patients at the time of diagnosis was 72.9 years and the mean time of snuff use prior to cancer diagnosis was 42.9 years. This case series shows that Swedish snuff may not be a harmless alternative to smoking.

This article presents a comparative clinical study of reinforced zinc oxide eugenol (EBA) cement and amalgam used as retrograde root filling materials. All patients were followed for a minimum of 3 years after surgery. Clinical and radiographic evaluation was performed. Successful healing with complete bone regeneration was noted in 57% in the reinforced zinc oxide eugenol group compared with 52% in the amalgam group. Uncertain healing with a certain degree of bone regeneration was seen in 24% in the reinforced zinc oxide eugenol group compared with 19% in the amalgam group. Unsuccessful healing with failure of bone regeneration was seen in 20% in the reinforced zinc oxide eugenol group compared with 29% in the amalgam group. Statistical analysis failed to show any significant difference in healing between the two retrograde filling materials. The results of this study indicate that retrograde root filling with reinforced zinc oxide eugenol cement has a similar prognosis as with amalgam over a 3-year period.