Supramolecular interactions were studied in two planar model systems, 1,5- and 2,6-dibromoanthraquinones, prepared on Au(111) using scanning tunneling microscopy. In both systems, we found rigid triangular structures that consisted of simultaneous halogen bonds and hydrogen bonds, as reported in protein−ligand complexes. We proposed molecular models that were well reproduced by first-principle studies and could be explained by halogen and hydrogen bonds. The distances, angles, and, strengths of the intermolecular bonds were measured in the observed structures, and showed good agreement with existing bulk data.

Interchain interactions in arrays of metal–organic hybrid chains were studied using scanning tunneling microscopy and ab initio calculations. The array of hybrid chains having a Ag–anthryl biradical were self-assembled by catalytic scission of Br–C bonds in 9,10-dibromoanthracene on Ag(111). An atomic model for the observed chain structures was proposed. Ag atoms in chains were alternatingly located at hollow sites, making slightly zigzaging structures. Between the hybrid chains, Br atoms located at hollow sites to form Br···H intermolecular bonds. Anthryl biradicals had two different apparent heights; this was explained by considering Br···H intermolecular bonds and intrachain steric repulsion. When a hybrid chain was laterally moved by manipulation techniques, Br adsorbates moved together with the chain, implying that they are stabilized by Br···H intermolecular bonds.

The electronic structures of self-assembled hybrid chains comprising Ag atoms and organic molecules were studied using scanning tunneling microscopy (STM) and spectroscopy (STS) in parallel with density functional theory (DFT). Hybrid chains were prepared by catalytic breaking of Br-C bonds in 4,4″-dibromo-p-terphenyl molecules, followed by spontaneous formation of Ag-C bonds on Ag(111). An atomic model was proposed for the observed hybrid chain structures. Four electronic states were resolved using STS measurements, and strong energy dependence was observed in STM images. These results were explained using first-principles calculations based on DFT.

Intermolecular structures of porous two-dimensional supramolecular networks are studied using scanning tunnelling microscopy combined with density functional theory calculations. The local configurations of halogen bonds in polymorphic porous supramolecular networks are directly visualized in support of previous bulk crystal studies.

Maxillary osteotomy is a common surgical procedure and often involves separation of the pterygomaxillary junction (PMJ), which is a “blinded” procedure with inherent risks. Knowledge of the PMJ structure is essential. It remains unclear whether patients with different facial types have different PMJ structures, or different surgical outcome. This study evaluated the computed tomographic images of 283 consecutive patients who received orthognathic surgery. Patients were classified into Angle class I, II, III and cleft lip/palate groups. The results showed that the PMJ was 5.1 ± 1.4 mm in thickness, 9.7 ± 1.7 mm in width, and 102.0 ± 4.0 degrees relative to the sagittal plane in the level of posterior nasal spine. There were no statistically significant differences in these measurements among the groups. The class III group demonstrated significantly smaller angle relative to the maxillary occlusal plane. The cleft group showed significantly longer vertical distance between the posterior nasal spine and the lower border of PMJ, shorter distance between the second molar and PMJ, and longer distance between the descending palatine artery and PMJ. With regard to postoperative outcome, the cleft group showed higher incidence of pterygoid plate fracture. The results in this study provide additional surgical anatomic information.