We investigated the compensatory trends of mesiodistal angulation of first molars in malocclusion cases. We compared differences in the angulation of first molars in different developmental stages, malocclusion classi...We investigated the compensatory trends of mesiodistal angulation of first molars in malocclusion cases. We compared differences in the angulation of first molars in different developmental stages, malocclusion classifications and skeletal patterns. The medical records and lateral cephalogrammes of 1 403 malocclusion cases taken before treatment were measured to evaluate compensation of molar angulation in relation to the skeletal jaw. The cases were stratified by age, Angle classification and skeletal patterns. Differences in the mesiodistal angulation of the first molars were compared among the stratifications. We observed three main phenomena. First,angulation of the upper first molar varied significantly with age and tipped most distally in cases aged,12 years and least distally in cases aged.16 years. The lower first molar did not show such differences. Second, in Angle Class II or skeletal Class II cases, the upper first molar was the most distally tipped, the lower first molar was the most mesially tipped, and opposite angulation compensation was observed in Class III cases. Third, in high-angle cases, the upper and lower first molars were the most distally tipped, and opposite angulation compensation was observed in low-angle cases. These data suggest that the angulation of the molars compensated for various growth patterns and malocclusion types. Hence, awareness of molar angulation compensation would help to adjust occlusal relationships, control anchorage and increase the chances of long-term stability.展开更多
Petroleum-based materials are often used in the packaging industry.However,the single use value of such products can be problematic with regard to proper waste disposal.As such,molded pulp packaging can be used as an ...Petroleum-based materials are often used in the packaging industry.However,the single use value of such products can be problematic with regard to proper waste disposal.As such,molded pulp packaging can be used as an alternative,given its ease of recycling,composting,and even-tual biodegradation.In this work,we aims to study the pulp properties of sunn hemp and its usage as molded pulp products.For this purpose,unbleached beaten and unbeaten soda pulps de-rived from the whole stem of sunn hemp were examined for their fiber morphology,fibrillation,fiber classification,and physical properties.The sunn hemp pulp was subsequently molded using a batch molding machine.To determine the hydrophobicity of the molded pulp products,the molded samples were manufactured with and without additives.Finally,some properties of the molded pulp products were examined and compared with the commercially available bleached bagasse molded pulp products.It was observed that the molded products made from sunn hemp pulp with additives had a higher water contact angle than that of the commercial products.In terms of general usage,the molded products from sunn hemp pulp with additives were found to be capable of storing hot water,hot cooking oil,as well as microwaving water.We concluded that the sunn hemp pulp could be used as an alternative fibrous raw material in the production of molded pulp packaging.展开更多
基金supported by the Specific Research Project of Health Pro Bono Sector, Ministry of Health, China (200802056)
文摘We investigated the compensatory trends of mesiodistal angulation of first molars in malocclusion cases. We compared differences in the angulation of first molars in different developmental stages, malocclusion classifications and skeletal patterns. The medical records and lateral cephalogrammes of 1 403 malocclusion cases taken before treatment were measured to evaluate compensation of molar angulation in relation to the skeletal jaw. The cases were stratified by age, Angle classification and skeletal patterns. Differences in the mesiodistal angulation of the first molars were compared among the stratifications. We observed three main phenomena. First,angulation of the upper first molar varied significantly with age and tipped most distally in cases aged,12 years and least distally in cases aged.16 years. The lower first molar did not show such differences. Second, in Angle Class II or skeletal Class II cases, the upper first molar was the most distally tipped, the lower first molar was the most mesially tipped, and opposite angulation compensation was observed in Class III cases. Third, in high-angle cases, the upper and lower first molars were the most distally tipped, and opposite angulation compensation was observed in low-angle cases. These data suggest that the angulation of the molars compensated for various growth patterns and malocclusion types. Hence, awareness of molar angulation compensation would help to adjust occlusal relationships, control anchorage and increase the chances of long-term stability.
文摘Petroleum-based materials are often used in the packaging industry.However,the single use value of such products can be problematic with regard to proper waste disposal.As such,molded pulp packaging can be used as an alternative,given its ease of recycling,composting,and even-tual biodegradation.In this work,we aims to study the pulp properties of sunn hemp and its usage as molded pulp products.For this purpose,unbleached beaten and unbeaten soda pulps de-rived from the whole stem of sunn hemp were examined for their fiber morphology,fibrillation,fiber classification,and physical properties.The sunn hemp pulp was subsequently molded using a batch molding machine.To determine the hydrophobicity of the molded pulp products,the molded samples were manufactured with and without additives.Finally,some properties of the molded pulp products were examined and compared with the commercially available bleached bagasse molded pulp products.It was observed that the molded products made from sunn hemp pulp with additives had a higher water contact angle than that of the commercial products.In terms of general usage,the molded products from sunn hemp pulp with additives were found to be capable of storing hot water,hot cooking oil,as well as microwaving water.We concluded that the sunn hemp pulp could be used as an alternative fibrous raw material in the production of molded pulp packaging.
