Anthropoid origins in Asia? New discovery of amphipithecus from the eocene of burma.

A new fossil of the primate Amphipithecus mogaungensis Colbert from the late Eocene of Burma shows that this species has a mandibular and molar morphology very similar to Oligocene and post-Oligocene higher primates. It has an exceptionally deep jaw. Its brachybunodont first and second molars have smooth enamel but lack hypoconulids. The shape of its second molar is nearly square-an advanced higher primate feature. Amphipithecus mogaungensis and related taxon Pondaungia cotteri Pilgrim are the earliest known higher primates. They suggest that Southeast Asia was an early theater of higher primate diversification.

An abbreviated caries clinical trial design validated over 24 months.

Conventional caries trials last from 24 to 36 months. This study evaluated whether the previously established difference in efficacy between 1000- and 2500-ppm-fluoride dentifrices could be detected after 12 months. Caries was assessed by clinical visual assessment (CVA-simplified version of Dundee Selectable Threshold Method - DSTM), bitewing radiography, and Fiber Optic Transillumination (FOTI). Changes in status for individual surfaces were classified by means of pre-prepared matrices as 0 (unchanged), +1 (initiation or progression), or -1 (regression) and summed for each subject to yield an event score. Mean group event scores were calculated for each product. DSTM at the D(1) [enamel and dentin] threshold showed significant inter-group differences in mean event scores (p < 0.003) and D(1)MFS increment (< 0.007) at 12 months; these were confirmed at 24 months by traditional increment analysis (CVA & FOTI at the D(3) (dentin only) threshold + radiography, p < 0.03). This study confirms the validity of an abbreviated trial protocol.

Plaque antibacterial levels following controlled food intake and use of a toothpaste containing 2% zinc citrate and 0.3% Triclosan.

OBJECTIVES: To measure the levels of zinc and Triclosan present in plaque 12 hours post-brushing and following two weeks home use of a toothpaste formulation containing 2% zinc citrate and 0.3% Triclosan. To measure the levels of zinc and Triclosan in plaque following two weeks home use of the test toothpaste formulation together with a further morning's brushing and a day of controlled food intake. METHODS: A total of 104 subjects completed the study. Plaque samples were taken before use of the test toothpaste and again after a specified regime of product use and food intake. The samples were analysed for zinc or Triclosan. RESULTS: Levels of zinc and Triclosan in plaque 12 hours after last brushing and following a 2-week home usage of product, were 149.1 microg/g and 8.6 microg/g respectively. Following a morning brushing and a day of controlled food intake zinc and Triclosan levels were 94.7 microg/g and 4.1 microg/g respectively. These levels of agents were found to reduce pH drop in vitro. CONCLUSIONS: Regular use of a toothpaste containing 2% zinc citrate and 0.3% Triclosan can lead to a build-up of antibacterial agents in plaque that continue to work even after controlled food intake.

The effect of a 2% zinc citrate, 0.3% Triclosan dentifrice on plaque acid production following consumption of a snackfood.

OBJECTIVES: A) To assess plaque lactate production following consumption of three foods (cake, chocolate/caramel bar, sweetened coffee), and B) To measure the effect of a fluoride dentifrice containing 2% zinc citrate and 0.3% Triclosan on plaque lactate and pH drop following consumption of cake. METHODS: A) 10 subjects completed the first study. Plaque samples taken before and at 8,15 and 30 minutes after eating. Samples were analysed for lactate via Capillary Electrophoresis. B) 30 subjects completed the second study. Plaque samples were taken before and after cake and use of test dentifrice or no treatment control. Plaque pH and lactate content were assessed. RESULTS: A) Plaque lactate levels increased after all three foods; peak lactate levels occurred 8 minutes after eating. B) Plaque lactate concentrations after eating cake were 39.2mM for the control treatment and a significantly lower value, 23.6mM, for the test 2% zinc citrate, 0.3% Triclosan dentifrice. After food challenge, pH values were 5.53 for the no treatment group and a significantly higher value of 5.79 for the test dentifrice group. CONCLUSIONS: A toothpaste containing 2% zinc citrate, 0.3% Triclosan can significantly reduce plaque lactate generation and pH drop induced by cake, compared to no treatment control.

Air Force Dental Service commemorates golden anniversary, 1949 to 1999.

For 50 years, evolving from aviation dentistry to aerospace dentistry, the U.S. Air Force Dental Service has successfully met the challenge of supporting the mission of the Air Force as well as made significant contributions to the profession of dentistry. This commemorative article not only highlights its achievements but serves as an historical tribute to the Dental Service's past of honoring the mission of the Air Force.

A brief history of aerospace dentistry.

In April 2000, the National Academy of Sciences Institute of Medicine (NAS/IOM) Committee on Space Medicine held a workshop under contract with the National Aeronautics and Space Administration (NASA) to explore "innovative terrestrial medical care." There was also a NAS/IOM panel held on "Space Dentistry: Maintaining Astronauts' Oral Health on Long Missions." Air Force Dental Officer Col. Shannon E. Mills chaired the dental committee. Many questions were raised but few answers were available. Prevention was emphasized with the hope that within twenty to thirty years there may be a number of astronaut candidates with no existing dental restorations and with optimum oral health. However, there remains the concern that trauma to teeth could occur within the confines of a zero gravity space capsule as crew members carry out their daily responsibilities. The possibility is evident considering the duration of a space flight to Mars and back could require up to three years. The dental concerns of a space mission are only a small part of a much larger team effort, however, it is one not to be overlooked. An historical review of dentistry's involvement with America's flight and space programs of the 20th Century would be prudent. Many of same questions asked today were addressed in the early days of aviation dentistry as it transitioned into aerospace dentistry. Any past research and experiences would help serve as a foundation to build upon.

Hal Harrison Ramsey: pioneer Texas dentist of the Big Country.

Smaller cities and rural communities often have limited information regarding their early health care practioneers. This is even more evident for dentists, especially those on the frontier. The obstacles those dentists overcame while practicing their profession are interesting by today's standards and their historical contributions to the profession and their local communities are worth preserving. Hal Harrison Ramsey was a circuit riding dentist during the settlement days of the West Central region of Texas often referred to as the Big Country by its present day residents. His story begins in the 1880s and covers the evolution of dentistry practiced by preceptor trained individuals to a profession of graduates from accredited dental institutions of the early 20th century. A legacy of dentists and physicians have continued through each generation of the Ramsey family and will do so into the 21st century. Dr. Ramsey's dentistry exemplifies the profession as practiced on the frontier of the late 19th century, and the heritage of contributions to the Big Country by his family are noteworthy.

A new omomyid primate from the Wasatch formation of southern Wyoming.

A new omomyid primate, Arapahovius gazini, is represented by many jaws and teeth and a few tarsal bones from a 15-meter stratigraphic interval at the base of the uppermost one-third of the Main Body of the Wasatch Formation, south-central Wyoming, USA. This primate is a conspicuous element in a faunule which lived at about the same time as the fauna of the Lysite Member of the Wind River Formation, estimated to be in the interval 52-50 million years before present. Individuals referable to the new omomyid are chiefly specialized by the intricate corrugation of enamel on the occlusal surfaces of their incisors, premolars and molars and by relatively molariform posterior lower premolars. These specializations may be interpreted as adaptation toward a more herbivorous-frugivorous diet. The tarsal bones referred to Arapahovius suggest that animals in this genus were habitual leapers. This new omomyid bears 'omomyine' and 'anaptomorphine' characters and may have been derived from an earlier Wasatchian (earliest Eocene) 'anaptomorphine' such as Tetonoides pearcei Gazin. Arapahovius seems to have had no phylogenetic successors.

Late Eocene of Burma yields earliest anthropoid primate, Pondaungia cotteri.

In April 1978, a fragment of a primate lower jaw containing the second and third molar teeth was found in late Eocene exposures of the Pondaung Hills about 1 mile north-west of Mogaung village in northwestern Central Burma. This approximately 40-Myr-old specimen is the first fossil primate found in Burma since the fragmentary remains of the controversial earliest anthropoids Pondaungia cotteri Pilgrim and Amphipithecus mogaungensis Colbert were recovered more than 50 yr ago. The jaw described here is believed to represent further evidence of P. cotteri. Its recovery from undoubled late Eocene exposures coupled with its salient higher primate characters and excellent state of preservation provides the opportunity to substantiate further that the Pondaung primates of Burma are the earliest known record of the Anthropoidea.

HLA class II typing of whole genome amplified mouth swab DNA.

Postal collection of mouth swabs provides a cheap and convenient means of DNA sampling but hitherto has not provided sufficient genetic material for HLA typing by polymerase chain reaction using sequence-specific primers (PCR-SSP). This study examined the feasibility of collecting mouth swabs from a test population by post, amplifying the DNA by whole genome amplification and genotyping for selected HLA class II alleles. We optimised a strategy for whole genome amplification or primer extension preamplification using a random 15 base pair primer which resulted in a 1,000-fold increase in DNA template. The amplified DNA was of sufficient quality for analysis of selected HLA Class II alleles by PCR-SSP and PCR using sequence-specific oligonucleotide probes. To test the reliability of our data, blood DNA from 30 individuals in 10 families, previously tested for all DRB1 alleles in a routine diagnostic laboratory, was then tested in our laboratory for DRB1 *03 and *04 following whole genome amplification. Further whole genome amplified product from another 10 families was tested for DRB1 *03, *04 in our laboratory and then tested for all DRB1 alleles in a routine diagnostic laboratory. One repeat typing was required to achieve 100% concordance between laboratories. Amplification of whole genome amplified DNA by PCR-SSP was then extended successfully to low-resolution HLA DRB1, DQA1, DQB1 and DPB1 typing. Mouth swab collection by post, followed by whole genome amplification of DNA provides an effective strategy for genetic analysis of large cohorts. We have optimised conditions for HLA class II typing on whole genome amplified DNA collected by mouth swab, but this method could potentially be applied to low concentrations of DNA from other sources.