Further research is required into the extra-oral causes of halitosis, or bad breath, together with new methods for detection and treatment. In a comprehensive review of all global research on the condition, Curd Bollen and Thomas Beikler of the University of Dusseldorf, Germany, conclude that halitosis is a poorly researched disease, mainly due to the social taboos it presents. They also note that halitosis affects some 25% of the world population and has a large social and economic impact. Although poor oral hygiene, along with microorganisms present on the tongue, are the main causes of the problem, serious illnesses such as liver disease can also trigger halitosis. Bollen and Beikler found very few effective treatments for the problem, and recommend a thorough, multi-disciplinary approach for future research and development in order to generate accurate diagnoses and treatments.

Vascular endothelial growth factor (VEGF) plays roles in both blood vessel formation (angiogenesis) and bone formation (osteogenesis). Scientists knew that VEGF is a trigger for vascularization. However, a growing body of work suggests that it also modulates the behavior of cells that form and remodel bone. After reviewing the literature, a team led by Yan-Qi Yang of the University of Hong Kong, China, compiled the evidence supporting this dual role for VEGF. Long bones such as limbs are formed by a mechanism called ‘endochondral ossification’, and numerous studies suggest that VEGF regulates this process directly and indirectly through its angiogenic effects. Other bones, like those in the face, form from connective tissue via ‘intramembranous ossification’. VEGF similarly helps to coordinate migration and differentiation of bone cells during this process.

New understanding of protein–mineral interactions has led to a method of repairing diseased teeth using peptide coatings, a US study reveals. Mehmet Sarikaya of the University of Washington and co-workers at institutions around the USA have deconstructed the dental enamel protein amelogenin to identify natural peptides that share useful characteristics with crystal-binding peptides (hydrozyapatites). They found that one such peptide — ADP5 — binds with demineralized tooth dentin to form a strong layer. This behavior is very similar to natural cementum, which covers tooth roots and helps hold teeth in place. Cementum is, however, very prone to disease through infections that decrease its ability to mineralize. ADP5 appears to mimic cementum mineralization, and could be used to form a protective layer over diseased teeth, allowing regeneration to begin.

Extracts of Zelkova serrata, an East Asian plant used for food and medicinal purposes, contain compounds that may prove useful in treating some oral cancers. The prognosis for patients with such tumors is fairly poor: they have a five-year survival rate of around 50%. Since Z. serrata has proven useful for treating other medical conditions, Hoe-Jin Kang and Young-Joo Jang of Dankook University, Korea, tested whether extracts derived from twigs of this plant might have an effect on the growth of cell lines derived from different types of oral cancer. The researchers obtained one extract that proved specifically toxic to epidermoid carcinoma cells, triggering a cellular suicide mechanism that thwarts tumor growth. Further analysis of the molecules within this fraction may offer useful leads for future oral cancer drug development.

A knowledge base to retrieve, integrate and analyze multiple data types collected from saliva samples promises to transform healthcare. Saliva is ideally suited to non-invasive detection and monitoring of disease. However, the absence of a free resource that cross-references disease-based changes in the levels of biomolecules has hamstrung progress in identifying biomarkers of specific illnesses. To address this issue, a team led by Ji-Ye Ai and David Wong at the University of California in Los Angeles are spearheading the creation of the Salivaomics Knowledge Base (SKB), a data management system and web resource to facilitate the discovery of saliva biomarkers using systems biology. The researchers first defined a common and structured vocabulary to describe the diverse data types; now, they are creating a common interface to integrate protein, RNA and metabolite data from multiple independent databases.

Analysis of a popular orthodontics assessment tool shows that southern China requires a lower cutoff point than other regions. Using orthodontic data collected from 12–13-year-old students in southern China, Wen-li Lai and co-workers at Sichuan University, China, validated the Index of Complexity, Outcome and Need (ICON) — a computer program used to calculate the perceived severity of malocclusions (misaligned teeth) on a points scale and suggest a point at which treatment is necessary. The researchers compared the scores generated by ICON for the 335 students with individual scores given by 25 professional Chinese orthodontists. Lai and co-workers found that the current cutoff point of ICON used internationally is too high for this region, so they propose a lower cutoff point that is more in-line with the orthodontists' expert opinions.

After insertion of a crown, individuals with naturally thick gum tissue may have a higher chance of it regenerating properly, research from China shows. In a pilot study of 40 individuals, Hong-Chang Lai at the Shanghai Jiao Tong University School of Medicine and colleagues at this university and the University of Hong Kong, tracked the natural response of gum tissue (mucosa) for six months following a single front tooth crown insertion with no post-crown intervention. The researchers focused on the development of the papillae—the triangular sections of gum between teeth—around the crown. Their results showed that the participants with a naturally thicker mucosa tended to develop a neater, more aesthetically acceptable papilla around the crown, avoiding the so-called ‘black triangle’ effect of missing or discolored papilla.

Modeling of dental implant systems with nonlinear finite element analysis (FEA) can differentiate their resistance to physical stress. Chun-Bo Tang of Nanjing Medical University, China, along with dental and engineering colleagues in Nanjing, tested the FEA method in a study of three commonly used designs of implant from different countries. In three dimensions, they simulated the stresses of a force of 170 newtons exerted at an angle of 45° onto the top of the attachment point or abutment of each system. From their results, Tang and colleagues concluded that none of the implants was likely to fail under such a force. The way the implants distributed stress, however, suggested that the design from the USA was superior to those from Germany and Sweden, and was likely to be displaced a smaller distance when in use.

Revascularization of immature necrotic teeth is a reliable treatment alternative to conventional apexogenesis or apexification. In case 1, a 12-year-old boy had his necrotic, immature mandibular left second premolar treated with a revascularization technique. At a 24-month follow-up, periapical radiolucency had disappeared and thickening of the root wall was observed. In cases 2 and 3, a 10-year-old boy had his necrotic, immature, bilateral mandibular second premolars treated with the same modality. At 48-month (in case 2) and 42-month (in case 3) follow-ups, loss of periapical radiolucencies and increases in the root wall thickness were also observed.

The presence of a large palatal or maxillary defect after partial or total maxillectomy for tumor, trauma or congenital deformation poses a challenge to prosthodontists, particularly when the use of an implant cannot be considered. This case report described the use of an air valve in a hollow silicone obturator to manufacture an inflatable obturator that could be extended further into undercut area to retain itself. The inflatable obturator exhibited adequate retention, stability and border sealing, thereby improving the masticatory, pronunciation and swallowing functions of patients. It may be a suitable alternative treatment option to an implant-retained obturator.