The present work is an attempt to develop a new method to determine sex from the skull with lateral radiographic cephalometry and discriminant function analysis. The superciliary ridges, frontal sinuses, external occipital protuberance, and mastoid processes were adopted as objects of lateral radiographic cephalometric measurements. With discriminant functions created from 18 established cephalometric variables, a total of 100 cases were classified into two sexual groups with 100% accuracy in a random sample of Taiwanese adults. Therefore, we may obtain a much greater reliability of sex determination from skulls according to this newly developed technique.

The objective of this study is to test the validity of sex determination in children and adolescents using lateral radiographic cephalometry and discriminant function analysis. Fifty male and 50 female cephalograms of Taiwanese children were used (males and females with mean age of 15.52 +/- 1.38 and 15.67 +/- 1.54 years, respectively). Twenty-two cephalometric measurements were performed using computerized cephalometry. Statistical analysis shows that all measurements were sexually dimorphic (p < 0.05). Nine measurements, statistically validated and clinically relevant, were used for discriminant function analysis. A stepwise discriminant procedure selected seven of the nine variables, producing 95% accuracy in sex determination. Resubstitution classification reveals the same discriminant rate. Cross-validation classification (the leave-one-out method) reveals that the correct sex determination rate is 91%. However, the combination of four variables using both the stepwise procedure and the resubstitution method achieves a 92% accuracy rate. A cross-validation classification procedure with the same four variables resulted in a 91% accuracy rate. Therefore, this study uses four cephalometric measurements as the minimum number of traits yielding the maximum discriminant effectiveness of sex determination in children and adolescents.

ATP is a ligand of P2X family purinoceptors, and exogenous ATP administration evokes pain behaviors. To date, there is a lack of systematic studies to address relationships between endogenous ATP and neuropathic pain. In this report, we took advantage of a mouse model of resiniferatoxin (RTX)-induced neuropathic pain to address the role of endogenous ATP in neuropathic pain. After RTX administration, endogenous ATP markedly increased in dorsal root ganglia (DRGs) (p <0.01) and skin tissues (p<0.001). The excessive endogenous ATP was removed by apyrase, an ATP hydrolyzing enzyme, administration via either a lumbar puncture route (p<0.001) or an intraplantar injection (p<0.001), which led to the normalization of neuropathic pain. In addition, intraplantar treatment with apyrase caused mechanical analgesia. Linear analyses showed that the densities of P2X3(+) neurons (r=−0.72, p<0.0001) and P2X3(+) dermal nerves (r=−0.72, p< 0.0001) were inversely correlated with mechanical thresholds. Moreover, the contents of endogenous ATP in skin tissues were linearly correlated with P2X3(+) dermal nerves (r=0.80, p<0.0001) and mechanical thresholds (r=−0.80, p<0.0001). In summary, this study demonstrated that enhanced purinergic signalling due to an increase in endogenous ATP after RTX-induced nerve injury contributed to the development of neuropathic pain. The data in this report provide a new therapeutic strategy for pain control by targeting the endogenous ligand of purinergic signalling.

Immediate relief of compression resulted in the best recovery of motor and sensory nerve conduction. In contrast, delayed decompression restored only motor nerve conduction.

The aim of this study was to investigate anatomical variations in the digastric muscle. Anatomical dissections of the head and neck region were performed in 15 cadavers at the Anatomy Department during a gross anatomy course. Three cadaver heads revealed anatomical variations in the anterior belly of the digastric muscle. The positional relationships among the accessory muscle bundles, the anterior belly of the digastric muscle, and the mylohyoid muscle were examined. Innervating branches from the mylohyoid nerve were also investigated. The remaining 12 cadaver heads without accessory muscle bundles were used for comparison. Of the three heads with accessory muscle bundles, one head (male) had two muscle bundles of the unilateral type, one head (male) had symmetrical muscle bundles of the crossover type, and one head (female) had a mix of unilateral and crossover types. The likely explanation for these and various other anomalies reported in the literature is the complex morphogenesis of the first branchial arch. Therefore, clinicians should be aware of these anatomical variations of the submental region when performing surgical procedures involving the head and neck and when using computed tomography and magnetic resonance imaging for interpretation or differential diagnosis of neck masses.

During the dissection of a 73-year-old embalmed male cadaver, we noted unusual variations in the flexor compartment of the upper limb-bilateral axillary arch muscles, a three-headed biceps brachii muscle with two supernumerary bellies-and variations in the origin of the musculocutaneous and median nerves from the brachial plexus. The morphological and clinical significance of this unique coexistence of multiple neuromuscular variations are discussed.

To investigate whether 4-methylcatechol (4MC) could decrease the duration of the thermosensation disorder and promote the innervation of peptidergic intraepidermal nerve fibers (IENFs), we developed a resiniferatoxin (RTX)-induced neuropathic mouse model with thermal analgesia and skin denervation that was followed by daily 4MC treatment. On day 7 after RTX administration (RTXd7), the substance P (SP)(+) IENFs were completely depleted compared with the vehicle group (p < 0.0001), whereas the calcitonin gene-related peptide (CGRP)(+) IENFs were dramatically, but not completely, depleted (p < 0.0001). While SP(+) IENFs remained depleted (p = 0.0043), CGRP(+) IENFs were recovered by RTXd84 (p = 0.78). 4MC had no effect on the reinnervation of SP(+) IENFs, but markedly promoted the reinnervation of CGRP(+) IENFs on RTXd35 (p = 0.035). On RTXd56, CGRP(+) IENFs were comparable with the vehicle group (p = 0.39). In addition, 4MC normalized thermal analgesia on RTXd35 compared with RTX group (p = 0.007). In the current study, the significant promotion of reinnervation of CGRP(+) IENFs and thermal latencies on RTXd35 by 4MC indicated that CGRP(+) IENFs were responsible for the thermal transmission in chronic phase of RTX-induced neuropathy.