The Ninth and Tenth Costal Cartilages Are Available and Safe Options for Rhinoplasty: A Cadaveric Anatomical Study

SUMMARY

Some practitioners prefer the ninth costal cartilage for autogenous rhinoplasty, but few anatomical studies focus on tapering shape and harvesting safety regarding pneumothorax risk. Therefore, the authors studied the size and related anatomy of the ninth and tenth costal cartilages. Twelve fresh cadavers (24 ribs) were studied. The authors measured the length, width, and thickness of the ninth and tenth costal cartilages at the osteochondral junction (OCJ), midpoint, and tip. To evaluate safety during harvesting, the authors measured the thickness of the transversus abdominis muscle beneath the costal cartilage. The mean lengths of the ninth and tenth cartilages were 99.1 ± 25.0 and 60.6 ± 22.5 mm, respectively. The ninth cartilage was 11.8 ± 2.6, 9.0 ± 2.4, and 2.5 ± 0.5 mm wide, and the tenth cartilage was 9.9 ± 2.0, 7.1 ± 2.0, and 2.7 ± 0.5 mm wide at the OCJ, midpoint, and tip, respectively. The ninth cartilage was 8.4 ± 2.0, 6.4 ± 1.5, and 2.4 ± 0.6 mm thick, and the tenth cartilage was 7.0 ± 2.2, 5.1 ± 1.7, and 2.3 ± 0.5 mm thick at each point. For the transversus abdominis muscle, the thickness was 2.1 ± 0.9, 3.7 ± 1.0, and 4.5 ± 1.3 mm at the ninth cartilage and 1.9 ± 0.5, 2.9 ± 1.1, and 3.7 ± 1.4 mm at the tenth cartilage at each point. The size of the cartilage was sufficient for autogenous rhinoplasty. The transversus abdominis muscle provides thickness for safe harvesting. Furthermore, if this muscle is breached during cartilage harvest, the abdominal cavity is exposed, but the pleural cavity is not. Consequently, there is a very low risk of pneumothorax at this level.

The photochemical attachment of the O-glucoside of 3-hydroxykynurenine to alpha-crystallin: a model for lenticular aging

The young human lens contains a small metabolite from tryptophan called the O-glucoside of 3-hydroxykynurenine (3-HKG). Its function is to absorb most radiation between 295 and 400 nm, preventing it from reaching the retina. With age the concentration of this component decreases while the lens crystallins acquire covalently attached chromophores. This study investigates the photochemical attachment of 3-HKG to lens alpha-crystallin. Initial studies showed that alpha-crystallin photolyzed in the presence of 3-HKG developed a fluorescence (emission, 440 nm) and UV-visible spectrum similar to that found in aged human lens proteins. Extensive studies were then performed on the tryptic HPLC maps as monitored by photodiode array and fluorescent detection. Numerous photoproducts with either blue (emission, > 400 nm) or green (emission, > 500 nm) fluorescence were formed in addition to nonfluorescent compounds with absorption maxima above 300 nm. Comparisons were made between these model photoproducts and peptide maps from alpha-crystallin isolated from old human lenses. In terms of retention time and UV-visible spectra at least two of the peptides that appear in the model system are also present in the human samples. It is concluded that one of the aging processes in the human lens is the photochemically induced attachment of 3-HKG to lens proteins.

National survey of Korean dentists' knowledge and opinions: dental caries etiology and prevention

OBJECTIVE

Dentists have the potential to influence what their patients know and do regarding dental caries prevention. The practices of dentists and what they tell their patients are influenced, in part, by their own knowledge and opinions. The purposes of this study were to determine the level of knowledge and opinions about caries etiology and prevention among Korean dentists and to describe related factors.

METHODS

A pretested, 27-item questionnaire was mailed to 2,047 dentists, selected by a stratified random sampling allocated proportionately. A postcard reminder was sent to all dentists after one week. Nonrespondents were sent additional complete mailings after three, seven, and nine weeks. The response rate was 83 percent (n = 1,700 dentists).

RESULTS

Analysis of six factors thought to be related to knowledge about caries etiology and prevention showed that recent graduates and dentists who worked in public health centers were likely to be more knowledgeable about caries etiology and prevention than their counterparts (P < .05). In regression analysis of perceived effectiveness of caries-preventive procedures for children, recent graduates, males, and dentists who worked in public health centers tended to rate caries-preventive procedures more effective than other dentists (P < .05). Dentists who had experience with school-based preventive programs and dentists in rural areas were likely to rate caries-preventive procedures for adults more effective than other dentists (P < .05).

CONCLUSIONS

Overall, results of this study suggest that the majority of dentists do not know current information concerning etiology and prevention of dental caries, mechanisms of action of fluoride, and effectiveness of preventive procedures for children and adults. Efforts to enhance the level of knowledge and practices of Korean dentists about caries prevention should focus on strategies to educate older graduates and female dentists, especially those in private practice.