Mating system, mate choice and parental care in a bark beetle.

The cypress bark beetle, Phloeosinus armatus, is a common element of the dying cypress tree system in East-Mediterranean countries. Adult beetles congregate for breeding on this ephemeral resource. We studied three traits that characterize this beetle's sexual behavior and linked them to its reproductive success: mating system, mate choice, and parental care. We found that the females are the 'pioneering sex', excavating the mating chamber. The average female is slightly larger than the male, and female and male body size is correlated, demonstrating size-assortative mating. The time it takes for a male to enter the mating chamber is positively correlated with female size and negatively correlated with its own size, which is perhaps responsible for this assortative mating. Males remain in the gallery during the period of oviposition, gradually leaving soon after the eggs hatch. The number of eggs laid and tunnel length are positively correlated with male body size. Finally, in the presence of both parents, more eggs are laid than when the female alone is present, demonstrating the important contribution of biparental care for reproductive success. We suggest that the interaction between a monogamous mating system, assortative mating, and biparental care contributes to reproductive success.

The association between dental wear and reduced vertical dimension of the face: a morphologic study on human skulls.

OBJECTIVE: The aim of this study was to explore the relationship between dental wear and facial morphology, with particular reference to the occlusal vertical dimension, in modern human skulls. DESIGN: One hundred and three skulls (52 men and 51 women) between the ages of 20 and 50+ years old were studied. The selected skulls were from a modern period (the 17th and the 18th centuries) and included at least one entire condyle and had at least 3 posterior teeth (premolar or molar) in each quadrant to allow for dental articulation. Occlusal wear was evaluated using ordinal scale (0-4) and vertical occlusal dimension was evaluated by measuring upper facial height (UFH), lower facial height (LFH), LFH-to-UFH ratio (L-U-R) and dental wear. Based on the occlusal wear score, two groups were defined: with and without significant wear. RESULTS: Significant relation was observed between age and dental wear (P<0.01). No significant differences were found in the LFH (P=0.847) or UFH (P=0.108) between the two wear groups. In addition, no significant difference (P=0.132) was demonstrated in the LFH-to-UFH ratio between the groups. No difference was observed in the dental wear score between genders (P=0.321). CONCLUSION: Within its limitations, this study demonstrated that dental wear does not influence the vertical dimension of occlusion. Our assumption is that the dento-facial complex fully compensates for the dental effects of wear throughout life.

[Teeth--too early to eulogize!].

With the growing use of dental implants and the high success and survival rates, less effort is being made for treating and preserving teeth. Teeth, on some cases, are being extracted too early and become more affected by service interventions than by oral diseases. Though dental implants, bone grafts and other augmentation techniques are rather successful, the real long term results of such cases are not always highly predictable. Teeth have been proven over the years to survive for a very long time with an appropriate treatment and maintenance. Before declaring a tooth to be hopeless and scheduled for extraction, careful thought should be taken if this tooth is really hopeless and cannot be preserved. Risk factors for dental implant survival and success such as cigarette smoking, periodontal disease, and diabetes mellitus should also be accounted for. It should be kept in mind also, that nowadays, we are much better in treating periodontitis than we are in treating periimplantitis.