This retrospective study aimed at investigating indications, surgical approaches, and the materials used for orbital floor reconstructions, as well as the clinical follow-up, particularly with regard to postoperative complications. This study comprised 189 patients who underwent surgery for fractures of the orbital floor between 2003 and 2007. Diagnosis and treatment were based on both physical examination and computed tomography scan of the orbit. Patients were retrospectively analyzed for data, such as mechanism of injury, classification of fracture, and complications. The most common cause of injury was physical assault followed by traffic accidents. Surgery was conducted with a mean delay of 2.9 days after the incident. Mid lower eyelid incision was the most common surgical approach to the orbital floor. For orbital floor reconstruction, polydioxanone sheets (70.5%) were mainly used, followed by Ethisorb Dura (23.3%) and titanium mesh (6.2%). There were 19.0% of patients who showed postoperative complications: 5.8% suffered from persisting motility impairment, 3.7% from enophthalmos, 3.2% from consistent diplopia, 2.6% from ectropion, and 0.5% from orbital infection. Intraorbital hematoma (3.2%) represented the most severe complications, one patient suffered lasting impairment of sight and another one, complete blindness of the affected eye. If postoperative impairment of vision becomes evident, immediate surgical intervention is mandatory. Retrobulbar hematoma is more likely to occur in heavily traumatized patients with comminuted fractures and also in patients taking anticoagulative medication. The subciliary approach to the orbit and repeated operations by the same approach are associated with a higher risk of developing ectropion.

Complex human tissues harbour stem cells and/or precursor cells, which are responsible for tissue development or repair. Recently, dental tissues such as periodontal ligament (PDL), dental papilla or dental follicle have been identified as easily accessible sources of undifferentiated cells. The dental stem cell biology might provide meaningful insights into the development of dental tissues and cellular differentiation processes. Dental stem cells could also be feasible tools for dental tissue engineering. Constructing complex structures like a periodontium, which provides the functional connection between a tooth or an implant and the surrounding jaw, could effectively improve modern dentistry. Dental precursor cells are attractive for novel approaches to treat diseases like periodontitis, dental caries or to improve dental pulp healing and the regeneration of craniofacial bone and teeth. These cells are easily accessible and, in contrast to bone-marrow-derived mesenchymal stem cells, are more closely related to dental tissues. This review gives a short overview of stem cells of dental origin.

This retrospective study examined the occurrence of congenitally missing permanent teeth and the need for dental treatment in the Regensburg University Medical Centre of Eastern Bavaria. Using a dental administration software tool, a total of 1442 patients who presented for orthodontic treatment between 1994 and 2006 were identified. After exclusion of 89 patients with incomplete records, 1353 subjects (635 males and 718 females) remained for analysis. Of these, 1130 had no missing permanent teeth, 52 had cleft lips, 110 had one to two teeth missing, 34 had three to five missing teeth, and 27 had greater than or equal to six missing teeth. The analyses focused on the type and number of missing teeth and on differences in the severity of dental agenesis according to gender and to referrals from various geographic regions around Regensburg. The data were statistically analysed using two-tailed tests. The following teeth were most frequently missing: tooth 35 (5.9 per cent), 45 (5.1 per cent), 22 (4.0 per cent), 12 (3.6 per cent), 15 (3.1 per cent), and 25 (3.0 per cent). No statistically significant difference in gender was found for one to two missing permanent teeth (low degree), hypo- or oligodontia (severe degree), or cleft lip. The odds ratio (OR) of presenting with hypo- or oligodontia compared with no missing teeth was higher among subjects originating from geographic regions outside Regensburg than from those from Regensburg, and it was statistically significantly higher for patients from Passau {OR = 3.53 [95% confidence interval (CI) = 1.18-10.52]} and Landshut [OR = 3.65 (95% CI = 1.22-10.99)]. The high prevalence and severe degree of dental agenesis of permanent teeth found in these groups of patients likely reflects distinct referral patterns for patients originating from geographic regions outside Regensburg. These data reinforce the need for a specialized dental treatment centre with the capacity to adequately serve a large rural area in Eastern Bavaria.

Dental stem cells from human exfoliated deciduous teeth (SHED) and dental follicle cells (DFCs) are neural crest-derived stem cells from human dental tissues. Interestingly, SHED and DFCs can successfully differentiate into neuron-like cells. We hypothesized that SHED and DFCs have the same neural cell differentiation potentials. To evaluate neural cell differentiation, we cultivated SHED and DFCs in four different serum-replacement media (SRMs) and analyzed cell morphology, cell proliferation, and gene expression patterns before and after differentiation. In a standard cell culture medium, SHED and DFCs have not only similar cell morphologies, but they also have similar gene expression patterns for known stem cell markers. However, only SHED expressed the neural stem cell marker Pax6. After cultivation in SRMs, cell proliferations of DFCs and SHED were reduced and the cell morphology was spindle-like with long processes. However, differentiated DFCs and SHED had different neural cell marker expression patterns. For example, gene expression of the late neural cell marker microtubule-associated protein 2 was upregulated in DFCs and downregulated in SHED in SRM with the B27 supplement. In contrast, SHED formed neurosphere-like cell clusters in SRM with the B27 supplement, epidermal growth factor, and fibroblast growth factor-2. Moreover, SHED differentially expressed the glial cell marker glial fibrillary acidic protein, which in contrast was weakly or not expressed in DFCs. In conclusion, SHED and DFCs have different neural differentiation potentials under the same cell culture conditions.

The expression of receptor tyrosine kinases confers additional prognostic impact on disease-specific survival. EGFR overexpression is an independent negative prognostic factor.

This retrospective study aimed at evaluating the recurrence rates of keratocystic odontogenic tumors (KCOTs) that were enucleated with and without the application of Carnoy's solution (CS). The study included 36 KCOTs treated between 1996 and 2006. Recurrence rates were investigated in correlation with the respective treatment method applied. Additionally, any damage to the inferior alveolar nerve associated with treatment was analyzed. Treatments consisted of enucleation with (38.9%) or without (61.1%) the application of CS. Median follow-up was 4.5 years. Single enucleation showed a recurrence rate of 50%, but the additional application of CS reduced the recurrence rate to 14.3%. No detrimental effects of CS on the mandibular nerve were detected. Enucleation plus the application of CS reduced the recurrence rate of KCOTs compared with simple enucleation. The application of CS did not cause any damage to the mandibular nerve.

During the last decade, oral cytology has once again become the focus of scientific research. This new interest is due to the introduction of a cytobrush for cell collection as well as a computer-assisted analysis (Oral CDx). Although promising, the sensitivity and specificity of conventional oral brush cytology remains limited. To circumvent the problems and improve the accuracy, various adjunctive analytical methods have been attempted. DNA analysis, immunocytochemical and molecular analysis are suggested methodological cytology approaches to improve the validity of oral brush cytology. An increase in sensitivity (up to 100%) and specificity (up to 100%) of oral brush biopsy has been reported on localized pre-malignant and malignant lesions. Oral brush biopsy probably will not replace histopathology in the definitive diagnosis of oral cancer, but it might be valuable for the prevention of misdiagnosis of clinically doubtful oral lesions and for the monitoring of lesions that might proceed on to oral cancer.

This study measured maxillary sinus volume, evaluated the location of the semilunar hiatus in correlation to the nasal floor, and the incidence, location, and height of antral septa and discusses their clinical implications. Maxillary sinus volume was quantified in 65 cadavers (130 sinuses) by water application through the semilunar hiatus and measuring the used amount. The location of the semilunar hiatus was identified as distance from the nasal floor. The septa were counted, evaluated, and the size measured from the antral floor. The medium maxillary sinus volume was 12.5 mL (range, 5-22 mL). The medium location of the semilunar hiatus was 25.6 mm above the nasal floor (range, 18-35 mm). Thirty-five septa were counted in 130 maxillary sinuses. This equals an incidence of 27%. The medium height of the septa was 5.4 mm (2.5-11 mm). The main location of the septa was the region of the first molar (29%), the second molar (23%), and the second premolar (23%). The height, location, and number of septa as well as the height of the semilunar hiatus and volume of the maxillary sinus have to be taken into consideration to correctly plan the procedure and amount of grafting material in maxillary sinus floor elevation operations. Anat Rec, 292:352-354, 2009Rec, 292:352-354, . 2009 Wiley-Liss, Inc.