Personal Guide Assisted Orthognathic Surgery: Application of a T-shaped Tooth Bone Combined Supporting Osteotomy Guide Plate and Positioning Guide Plate.

ABSTRACT: The precise movement of the maxilla is particularly important for orthognathic surgery, especially for patients with maxillary segmentation. In this preliminary study, the authors present a new tooth bone combined with a supporting osteotomy guide and positioning guide to guide the osteotomy and reduction of the maxilla. Through our preoperative simulation and postoperative image fusion, the authors found that the overlapping area is more than 90%. According to compare of the virtual plans and the postoperative results based on distances from the maxillary land- marks to the horizontal plane, sagittal plane, and coronal plane, the surgical error was about 2mm. Our T-shaped guide provides a reliable method for patients with maxillary segmental osteotomy, which may be a useful alternative to the intermediate.

[Use of "gelatamp" colloidal silver gelatin sponge to prevent dry socket after extracting mandibular impacted teeth].

PURPOSE: To study the clinical effect of "gelatamp" colloidal silver gelatin sponge on preventing dry socket after extracting the mandibular impacted teeth. METHODS: 1350 teeth extracted from 976 patients who needed to extract the mandibular impacted teeth were divided into group A, group B and group C randomly. "Gelatamp" colloidal silver gelatin sponge was implanted into alveolar socket after teeth extraction in group A, with absorbable gelatin sponge was implanted into alveolar socket in group B and nothing was implanted into alveolar socket in group C. The incidence of dry socket was observed, the data was analyzed using SPSS10.0 software package. RESULTS: The incidence of dry socket was 0.44% in group A, 2% in group B and 4.44% in group C. There was significant difference in the incidence of dry socket between group A and group C(P<0.01). There was also significant difference between group B and group C(P<0.05) and between group A and group B(P<0.05). CONCLUSIONS: The results demonstrate that "gelatamp" colloidal silver gelatin sponge can prevent the occurrence of dry socket after teeth extraction, which is of wide clinical use.

[The mutations of the D-loop hypervariable region II and hypervariable region III of mitochondrial DNA in oral squamous cell carcinoma].

OBJECTIVE: To investigate the frequency of mitochondrial DNA (mtDNA) D-loop hypervariable region II (HVR II) and hypervariable region III (HVR III) mutations in oral squamous cell carcinoma (OSCC) and their correlation to provide the new targets for the prevention and treatment of OSCC. METHODS: The D-loop HVR II and HVR III regions of mtDNA in seven cases with OSCC tissues, matched with paracancerous tissues and normal mucosa tissues from the same case, were amplified by polymerase chain raction (PCR), then were detected by direct sequencing to find the mutantsites after the comparison of all sequencing results with the mtDNA Cambridge sequence in the GenBank database. RESULTS: 82 (56 species) nucleotide changes, with 51(26 species) nucleotide polymorphism, were found after the comparison of all sequencing results with the mtDNA Cambridge sequence in the GenBank database. 31(30 species) mutations, with 21 located within the HVR II and HVR III regions, were found in 3 tumor tissue samples, their paracancerous and normal mucosa tissue were found more polymorphic changes but no mutation. The mtDNA D-loop HVR II and HVR III regions mutation rate was 42.9% (3/7) in OSCC. CONCLUSION: The mtDNA D-loop HVR II and HVR III regions were highly polymorphic and mutable regions in OSCC. It suggested that the D-loop HVR II and HVR III regions of mtDNA might play a significant role in the tumorigenesis of OSCC. It may become new targets for the gene therapy of OSCC by regulating the above indexes.