Location of mental foramen based on soft- and hard-tissue landmarks in a chinese population.

The purpose of the present study was to determine the location of the mental foramen (MF) based on soft- and hard-tissue landmarks, to facilitate prediction of the location of this structure during facial and dental surgery. Forty-two hemispheres of 21 adult cadavers (16 men and 5 women; aged 30-75 years) were dissected to expose the MF. The locations of the MFs were evaluated with direct and photographic measurements. Most of the MFs presented a single foramen (95%), except for only 2 cases with double foramina (5%). The MFs localized 23.38 +/- 2.00 mm inferior and 3.55 +/- 1.70 mm medial to the cheilion in the front view while 23.59 +/- 2.11 mm inferior and 7.19 +/- 3.03 mm posterior to the cheilion in the lateral view. Based on the hard-tissue landmarks, we found that most of the MFs localized inferior the second premolar in most of the cases (73.8%), and the MFs localized 23.34 +/- 2.39 mm below the cusp tip of the second premolar, 16.56 +/- 2.53 mm below the inferior alveoli, and 15.56 +/- 1.74 mm superior the bottom of the mandible. The position of the MF varied from 8.7 degrees medial to 15.5 degrees posterior in the vertical angle with the change of surgical body position from supine to lay-side position. Our results may provide a more detailed information to predict the location of the MFs.

[Study on the baseline contents and reference maximum limit standard of heavy metals and harmful element of 23 Chinese herbs in Northern China].

OBJECTIVE: This study was carried out to obtain the baseline contents and establish the reference maximum limits of heavy metals and harmful element in China. METHODS: According as Chinese standard methods of heavy metals and harmful element, 254 Chinese herbs were determined. RESULTS: The contents of lead, cadmium, mercury and arsenic in different Chinese herbs were (1.78 +/- 1.98), (0.17 +/- 0.24), (0.04 +/- 0.06) and (0.72 +/- 0.69)mg/kg, respectively. In the process of establishing the reference maximum limit standards of these harmful substances, the dietary intakes which including the intakes from food, beverage and drinking water were necessarily considered. The intakes including dietary and Chinese herbs of per person per day (and the percent of ADI) of lead, cadmium, mercury and inorganic arsenic were 102.9 microg (45.7%), 21.4 microg (34.0%), 5.7 microg (5.7%) and 81.0 microg (60.5%), respectively. We recommended the reference maximum limit standards of lead, cadmium, mercury and arsenic which in Chinese herbs were 5.0 mg/kg, 0.3 mg/kg, 0.2 mg/kg and 2.0 mg/kg, respectively. CONCLUSION: The survey of baseline level of heavy metals and harmful element was successful. The intakes of these harmful substances were safe to human health. The maximum level standards of lead, cadmium, mercury, arsenic in plant Chinese herbs submitted by our coordinated group have been accepted by Chinese Herbs Codex, 2005 version. This standard is suitable for quality standards in plant Chinese herbs.

[2000 Chinese total diet study--the dietary lead and cadmium intakes].

OBJECTIVE: In order to assess the safety of dietary lead (P) and cadmium (Cd) intakes in different areas in China, we carried out Chinese total diet study (TDS) in 2000 and obtained total lead and cadmium contents and intakes data and assessed the safety of lead and cadmium in Chinese dietary. METHODS: Using the Chinese total dietary study method, the analytical samples were obtained in different areas by food consumption survey, food aggregation, food sampling and preparation. The levels of dietary lead and cadmium were determined by the graphite furnace atomic absorption spectrometry. The dietary lead and cadmium intakes in different areas were obtained by timing the food consumption data and the lead and cadmium content in different dietary samples. The safety of dietary lead and cadmium was evaluated in Chinese four regions and average adults by using the dietary lead and cadmium PTWI recommended by JECFA of FAO/WHO. RESULTS: The dietary lead and cadmium intakes of the adult were estimated in Chinese total diet study. Dietary lead and cadmium (of PTWI) intakes in four different regions and average adults were 135.6 microg (60.3%) and 18.3 microg (29.1%), 33.6 microg (14.9%) and 12.1 microg (19.2%), 25.6 microg (11.4%) and 27.6 microg (43.8%), 129.8 microg (57.7%) and 30.8 microg (48.9%), 81.1 microg (36.1% ) and 22.2 microg (35.3%) respectively. Except South 1, mainly sources of dietary lead were cereals, legumes, eggs and vegetables, that of other regions were cereals and vegetables; Mainly sources of dietary cadmium, North 1 were cereals, aquatic foods and vegetables, North 2 and South 2 were cereals and vegetables, South I were cereals, meats, aquatic foods and vegetables. Lead and cadmium concentrations in other food groups of four regions were well below the maximum levels of China national standard, except a few samples in some areas exceeded maximum levels, such as lead of eggs in South 1 region exceeded 8. 1% of maximum levels as well as cadmium of aquatic foods of in North 1 and South 1 exceeded 49.0% and 27.6% of maximum levels respectively. CONCLUSION: The results indicate that the dietary lead and cadmium intakes were safe in different regions. Only lead and cadmium concentrations in a few samples of some areas exceeded maximum levels of China national standard.