Government initiatives should promote high quality dental care to improve the overall health of the population, say Chinese researchers. Oral infections cost the global economy millions of dollars annually, and are closely associated with diseases such as diabetes and cancer. Improving oral health is a central goal of the Healthy China 2030 program, launched recently by the Chinese government. Xuedong Zhou at Sichuan University in Chengdu and co-workers reviewed challenges facing oral health in China and suggest guidelines to enable the government to achieve their aims. Tooth decay and gum disease are key concerns, and recent policy changes emphasize the importance of healthy lifestyles, integrating oral health into regular physical checks, and educating the population. The researchers also recommend managing oral health during treatment for other chronic diseases, and ensuring high quality training for professionals.

Bone mass is important for dental implant success and is regulated by mechanoresponsive osteocytes. We aimed to investigate the relationship between the levels and orientation of tensile strain and morphology and orientation of osteocytes at different dental implant positions in the maxillary bone. Bone biopsies were retrieved from eight patients who underwent maxillary sinus-floor elevation with β-tricalcium phosphate prior to implant placement. Gap versus free-ending locations were compared using 1) a three-dimensional finite-element model of the maxilla to predict the tensile strain magnitude and direction and 2) histology and histomorphometric analyses. The finite-element model predicted larger, differently directed tensile strains in the gap versus free-ending locations. The mean percentage of mineralised residual native-tissue volume, osteocyte number (mean ± standard deviations: 97 ± 40/region-of-interest), and osteocyte shape (~90% elongated, ~10% round) were similar for both locations. However, the osteocyte surface area was 1.5-times larger in the gap than in the free-ending locations, and the elongated osteocytes in these locations were more cranially caudally oriented. In conclusion, significant differences in the osteocyte surface area and orientation seem to exist locally in the maxillary bone, which may be related to the tensile strain magnitude and orientation. This might reflect local differences in the osteocyte mechanosensitivity and bone quality, suggesting differences in dental implant success based on the location in the maxilla.

Cells and tissues have been identified that produce a signaling molecule essential for bone remodeling in orthodontic patients. Directional mechanical force, when applied to teeth, instigates changes to remodel the bone around the tooth. Researchers from the University of Pennsylvania School of Dental Medicine in Philadelphia, led by Dana Graves, genetically altered mice to remove ‘RANKL’, a protein thought to be a mediator in the breakdown of bone. The team found that the immune cells responsible for producing RANKL are primarily found in the tissue connecting tooth roots to the ridges of bone containing the tooth sockets and the protective cells that line the bones. Removing RANKL impaired the ability of the teeth to move in response to external directional force. This study provides insights into the relationship between RANKL production and orthodontic tooth movement.

With the aim of deepening clinical understanding, researchers have conducted a bilingual literature review of a rare oral tumor. Due to its scarcity, relatively few instances of ectomesenchymal chondromyxoid tumor (ECT) exist in English and German medical literature, yet differentiation from other oral tumors remains important. This, combined with the presentation of a new patient with an especially rare form of the disease, led Astrid Truschnegg and her team of scientists from Austria’s Medical University Graz and IMAH to compile and assess the research conducted on ECT. The team searched papers published up to late-2016 and identified proteins commonly expressed by ECTs, patterns of cellular and tissue structure, genetic similarities, as well as a shared embryonic origin of tumor-associated cells. This review offers clinicians and researchers an accessible brief of current knowledge on a rare, yet significant oral disease.

How well a dental filling or crown performs depends not only on the strength of ceramic material used but also on its thickness and type. Sun-Young Kim of Seoul National University and colleagues investigated how the thickness and type of glass-based ceramic affected how well it transmitted light and thus how well resin cement underneath it hardened. Orthodontists use a special ‘curing’ light to harden resin cement and create a strong bond between the ceramic material and the underlying mouth tissue. They shined light on different types of ceramic plates of similar shade but varying thickness and found that both their ability to transmit light and how well the resin cement underneath them hardened varied significantly. They conclude that orthodontists should not only choose ceramics for dental treatments based on their inherent strength, but should also consider how well they transmit light.

Whole-body vibration and administration of a hormone used to treat osteoporosis can enhance bone healing at the site of a titanium implant. Toru Ogawa of Tohoku University Graduate School of Dentistry in Sendai, Japan, and colleagues gave anti-osteoporosis medications, either parathyroid hormone or the bisphosphonate drug alendronate, to female rat models of osteoporosis. After three weeks of drug administration or a saline control, the researchers inserted titanium implants into the rats’ leg bones. Half the rats were then exposed to whole-body vibration, which applies low-magnitude, high-frequency mechanical forces. A multitude of tests showed that parathyroid hormone improved bone healing at the implant more than alendronate or saline did. The vibrational stimulus further increased the healing. The findings suggest that these treatments could aid in oral bone healing for patients receiving dental implants.

Ensuring oral health in early childhood could prevent the development of jaw misalignment later in life. Xuedong Zhou, of China’s Sichuan University, and colleagues reviewed the latest research on how common dental conditions in children influence malocclusion, where the teeth of the upper and lower jaws do not properly align, causing problems such as overbite, where the lower teeth overlap the upper teeth, or open bite, where a space remains between the upper and lower teeth when the mouth is closed. Tooth decay, prolonged thumb sucking, trauma, and the appearance of additional baby teeth are but a few of the factors that can ultimately lead to malocclusion in adulthood. Early and adequate management of these factors will establish healthy dentition and alleviate or avoid malocclusion, the researchers conclude.

Defences against gum disease are bolstered via increased expression of the proteins that seal the gaps between oral epithelial cells. Previous work has indicated that these tight junction proteins are involved in gum disease, but their role is unknown. ZhongHao Liu from Binzhou Medical University, Yantai, China, and colleagues investigated how Porphyromonas gingivalis, the most common bacteria associated with gum disease, affects the expression of tight junction proteins in cultured oral epithelial cells. In the early stages of infection, the expression of several tight junction proteins increased, particularly in the presence of extracellular ATP, an indicator of nearby cell damage. The findings provide insight into the early host response to P. gingivalis, the increased expression of tight junction proteins strengthening the seal between cells as a defence against bacterial invasion.