Some talpid moles show one of the most specialized suites of morphological characters seen among small mammals. Fossorial and more generalized shrew-looking moles inhabit both North America and Eurasia but these land masses share none of the same genera. One of the central questions of mole evolution has been that of how many times specialized fossorial habits evolved. We investigated the origin of mole characters with a maximum parsimony analysis of 157 characters, mostly craniodental and postcranial, of representatives of all 17 living mole genera and three shrews and one hedgehog as outgroups. The result was one most-parsimonious tree and its most novel aspect was the position of a Japanese shrew mole clade (Urotrichus, Dymecodon), which branched off after Uropsilus and was not closely related to the American shrew mole (Neurotrichus). The desmans (Galemys and Desmana) were the next clade in the tree, followed by Neurotrichus. We confirmed the monophyly of the Eurasian fossorial mole clade Talpini (Euroscaptor, Parascaptor, Mogera, Scaptochirus and Talpa). Condylura, the star-nosed mole from North America, was sister group to a clade consisting of the Talpini plus Scaptonyx and the Scalopini (Scalopus, Scapanus, Parascalops, and Scapanulus). Based on our results and on the assumption that moles originated in Eurasia, it is most parsimonious to infer one migration from Eurasia to North America and two back-migrations to Eurasia. It is ambiguous if Talpini and Scalopini evolved their full fossorial habits independently or not.

The phylogenetic relationships within the family Talpidae (Mammalia, Insectivora) were inferred from parsimonious analysis of 55 morphological characters, which were collected from 43 skulls of 22 species, and which included all of the extant genera in the current taxonomy of the Talpidae. Two equally parsimonious cladograms were obtained. The Uropsilinae, Desmaninae and Talpinae subfamilies formed monophyletic clades, and the Desmaninae and Talpinae subfamilies were sister clades. The Talpinae subfamily was subdivided into the following clades: Urotrichus, Dymecodon, Scalopus-Scapanus, Parascalops-Scapanulus, Condylura, Neurotrichus, Scaptonyx and Talpini (Talpa, Euroscaptor, Scaptochirus, Parascaptor and Mogera). The Urotrichini (Urotrichus, Dymecodon and Neurotrichus) and Scalopini (Scalopus, Scapanus, Parascalops and Scapanulus) were considered to be paraphyletic, and were defined primarily by their ancestral characteristics. Since the genus Dymecodon was not clustered with Urotrichus, it was considered to be a valid genus, and not just a junior synonym of the latter. The Asian genus Euroscaptor was found to be a paraphyletic group, and deserves further systematic revision. The evolution from semi-fossorial habit to fully fossorial habit seems to have occurred three times in the Scalopus-Scapanus, Parascalops-Scapanulus and Talpini clades. The migration of the Talpinae to North America from Eurasia probably occurred on four separate occasions in the Scalopus-Scapanus, Parascalops, Condylura and Neurotrichus lineages.

The purpose of this study was to clarify the prevalence and degree of root resorption induced by orthodontic treatment in association with treatment factors. The files of 243 patients (72 males and 171 females) aged 9-51 years were randomly selected from subjects treated with multi-bracket appliances. The severity of root resorption was classified into five categories on radiographs taken before and after treatment. The subjects were divided into extraction (n = 113 patients, 2805 teeth) and non-extraction (n = 130 patients, 3616 teeth) groups and surgical (n = 56 patients, 1503 teeth) and non-surgical treatment (n = 187 patients, 4918 teeth) groups. These subjects were also divided into two or three groups based on the duration of multiloop edgewise archwire (MEAW) treatment, elastic use, and total treatment time: 0 month (T1; n = 184 patients, 4831 teeth), range 1-6 months (T2; n = 37 patients, 994 teeth), more than 6 months (T3; n = 22 patients, 596 teeth); range 0-6 months (n = 114 patients, 3016 teeth) more than 6 months (n = 129 patients, 3405 teeth); range 1-30 months (n = 148 patients, 3913 teeth) and more than 30 months (n = 95 patients, 2508 teeth). The prevalence of overall and severe root resorption evaluated by the number of subjects and teeth was compared with a chi-square test. A Student's t-test for unpaired data was used to determine any statistically significant differences. The prevalence of severe root resorption based on the number of teeth was significantly higher in the group with extractions (P < 0.01). Longer use of a MEAW appliance and elastics also produced a significantly higher prevalence of root resorption (P < 0.05). On the other hand, the prevalence of severe root resorption was not significantly different between the subjects treated with or without surgery, but there was a significant increase when treatment time was prolonged (P < 0.05). A significant difference was found in the amount of root movement of the upper central incisors and the distance from their root apices to the cortical bone surface (P < 0.05). These are regarded as essential factors in the onset of root resorption. These results indicate that orthodontic treatment with extractions, long-term use of a MEAW appliance and elastics, treatment time, and distance of tooth movement are risk factors for severe root resorption.