Hand and handprint measurements in the estimation of stature in a Sri Lankan population / Mediciones de manos y huellas de manos en la estimación de la estatura en una población de Sri Lanka

SUMMARY: The present study was undertaken to generate sex-specific simple and multiple regression models for the estimation of stature using hand and handprint measurements in a Sri Lankan population. The sample comprises 51 males and 66 females in the age range of 20 to 26 years. The stature and eight measurements from each hand and its corresponding print of each subject were collected using standard anthropometric instruments and techniques. All hand and handprint measurements showed significantly positive correlation (p value < 0.05) with the stature in both sexes. Stature prediction accuracy for simple linear regression equations ranged from ±4.41-5.92 cm and ±4.0- 5.22 cm for the left and right hand measurements in males and females, respectively. The corresponding figures for the left and right handprint measurements were ±4.57-5.95cm and ±4.36-5.52 cm, respectively. The highest stature prediction accuracy was shown by the multiple regression models derived from hand measurements. The stature estimating formulae reported in this study using hand measurements have important application in the identification of unknown human remains, particularly when they are partial, mutilated or dismembered. Similarly, it is envisaged that formulae derived from the handprint measurements will be useful in crime scene investigations.

RESUMEN: El estudio se llevó a cabo para generar modelos de regresión simple y múltiple de acuerdo al sexo, para la estimación de la estatura utilizando medidas de manos y huellas de manos en una población de Sri Lanka. La muestra comprendió 51 hombres y 66 mujeres entre 20 a 26 años de edad. Se analizaron la estatura y ocho medidas de cada mano y su impresión correspondiente de cada sujeto utilizando instrumentos y técnicas antropométricas estándar. Todas las mediciones de manos y las huellas de manos indicaron una correlación significativamente positiva (valor de p <0.05) con la estatura en ambos sexos. La precisión de la predicción de la estatura para las ecuaciones de regresión lineal simple varió de ± 4,41 a 5,92 cm y ± 4,0 a 5,22 cm en las medidas de la mano izquierda y derecha en hombres y mujeres, respectivamente. Las cifras correspondientes para las medidas de la huella de la mano izquierda y derecha fueron ± 4,57-5,95 cm y ± 4,36-5,52 cm, respectivamente. La precisión de predicción de la estatura más alta se mostró mediante los modelos de regresión múltiple derivados de las mediciones manuales. Las fórmulas de estimación de la estatura reportadas en este estudio utilizando medidas manuales tienen una aplicación importante en la identificación de restos humanos desconocidos, particularmente cuando son parciales, o se encuentran mutilados o desmembrados. Además, se prevé que las fórmulas derivadas de las mediciones de huellas de manos serán útiles en las investigaciones criminales.

Influence of Catastrophizing and Personality Traits on Recalled Ratings of Acute Pain Experience in Healthy Young Adults.

Objective: To investigate whether pain catastrophizing and personality traits bias recalled ratings of acute pain in an experimental tonic pain model. Subjects and Setting: Fifty-six undergraduates (14 males) recruited from the University of Peradeniya (mean age 21.7 ± 0.8 SD years). Design and Methods: Participants completed the Pain Catastrophizing Scale and the Eysenck Personality Questionnaire. They were subjected to two cold pressor tests (dominant and non-dominant hands) and pain threshold, maximum pain intensity, and pain tolerance were recorded. One-week later, the maximum pain intensities of both hands were recalled and percentage distortions in recalling were calculated. Based on a 180 s cutoff, two participants were considered pain-insensitive during the test and were excluded from the analysis. Results: The maximum pain intensity was recalled with a moderate accuracy (Intraclass Correlation Coefficients = 0.68 for dominant and 0.59 for non-dominant hands). Hierarchical multiple regression analyses revealed that maximum pain intensity ( P < 0.001) and pain catastrophizing ( P < 0.001) contributed significantly to recalled pain intensity, and only pain catastrophizing contributed significantly ( P < 0.001) to percentage distortion in recalling with positive ß-coefficients. Participants who consistently overrated pain for both hands in recalling scored significantly higher on catastrophizing ( P < 0.001). Conclusion: This study demonstrated that memory for painful events in healthy subjects was reasonably accurate over a period of 1 week. Pain catastrophizing biased pain recall, whereas among personality traits only neuroticism exhibited a weak positive association with the recalled ratings.

Association of learning approaches with academic performance of Sri Lankan first-year dental students.

BACKGROUND: Primarily deep approach (DA) and surface approach (SA) to learning have been distinguished among students. PURPOSE: We aimed to determine the learning approaches and their association with the academic performance of a batch of 1st-year Sri Lankan dental students. METHODS: Learning scores of students were calculated using the revised two-factor study process (R-SPQ-2F) questionnaire and they were correlated with the academic performance of students. RESULTS: The 80.65% of students showed a greater DA score than SA score. Mean values of students' DA and SA scores were 31.79 ± 6.1 and 22.74 ± 5.5, respectively. A positive statistically significant correlation (r = .3, p < .05) was observed only between DA score and marks of Short Answer Questions in anatomy. CONCLUSIONS: This sample of students uses both deep and surface learning approaches with more preference to DA than SA. The correlation between learning approaches and academic performance was inconsistent.

Effects of chewing and swallowing behavior on jaw opening reflex responses in freely feeding rabbits.

It has been reported that the jaw opening reflex (JOR) evoked by intra-oral innocuous stimulation was suppressed during a reflex swallow in anesthetized animals only. However, the mechanism of JOR inhibition during swallowing has not yet been elucidated. The aim of the present study was to investigate the effects of peripheral nerve stimulation on masticatory behaviors, as well as the modulation of low threshold afferent evoked JOR responses during chewing and swallowing in freely feeding animals. The JOR in the digastric muscle was evoked by low threshold electrical stimulation of the inferior alveolar nerve (IAN). Changes in the peak-to-peak amplitude of digastric electromyographic responses were compared among the phases of chewing and swallowing. IAN stimulation did not produce any differences in cycle duration, gape of the jaw in one cycle, or swallowing interval, suggesting a minimal effect on feeding behaviors. The JOR amplitude during the fast-closing, slow-closing, and slow-opening phases of chewing was significantly smaller than that of the control (recorded when the animal was at rest) and fast-opening phase. During swallowing, the JOR amplitude was significantly less than the control. Inhibition of the JOR during swallowing is assumed to prevent unnecessary opposing jaw opening motion.

Differential involvement of two cortical masticatory areas in modulation of the swallowing reflex in rats.

To clarify the functional role of cortical descending inputs involved in the swallowing reflex, the effect of electrical stimulation of two cortical masticatory areas (CMAs: A- and P-area) on rhythmic jaw movements (RJMs) and superior laryngeal nerve (SLN)-evoked swallows were studied. RJMs and swallowing reflex were elicited by repetitive electrical stimulation of CMAs and the SLN, respectively. The electromyographic activities of jaw-closer (masseter), jaw-opener (digastric), and laryngeal-elevator (thyrohyoid) muscles were recorded to identify the RJMs and swallowing reflex. The number of evoked swallows was significantly lower, and swallowing interval was significantly longer during A-area stimulation compared with those without stimulation. Conversely, these parameters were not significantly altered during P-area stimulation. The inhibition of swallows by A-area stimulation was not affected by an increase in sensory input by wooden stick application between upper and lower teeth, or A-area stimulation preceding SLN stimulation. The present findings suggest that the swallowing reflex is inhibited by activation of the A-area, but not the P-area. Since no changes in swallows were seen after the increase in intraoral sensory input and prior activation of masticatory central pattern generator (CPG), swallowing inhibition may be mediated by direct inputs from the A-area or inputs via the masticatory CPG into the swallowing CPG.

Changes in reflex responses of the genioglossus muscle during sleep in rabbits.

Changes in reflex responses in the genioglossus (GG) muscle evoked by electrical stimulation of the inferior alveolar nerve and GG muscle tone (background activity, BGA) were investigated during sleep-wakefulness stages in rabbits. The GG muscle showed two types of electromyographic activity patterns: a respiration-related phasic activity and non-respiration-related activity. GG reflex responses and BGA exhibited a stage-dependent decrease as they were constantly suppressed from quiet wakefulness to non-rapid eye movement sleep to rapid eye movement sleep (REMS). Degree of suppression of reflexes was much larger than that of BGA regardless of GG activity patterns. When amplitude of reflex responses was compared between with and without rapid eye movements during REMS, no difference between the conditions was noted. These results suggest that excitability of the GG muscle is affected by sleep stages by not only a modulation of excitability in motoneurons but also in interneurons involved in the reflex arc.

Effects of food consistency on the pattern of extrinsic tongue muscle activities during mastication in freely moving rabbits.

The effects of physical characteristics of foods on the coordination of extrinsic tongue muscle activities during natural mastication were evaluated. Electromyograms of tongue-retractor (styloglossus, SG) and tongue-protractor (genioglossus, GG) muscles as well as the jaw-movement trajectories were recorded during raw rice and chow pellet chewing in the freely moving rabbit. Each masticatory cycle included a jaw closing (Cl) phase consisting of a fast-closing (FC) and a slow-closing (SC) phase, and a jaw opening (Op) phase. The duration of the Cl and SC phases was found to be much larger while the duration of the FC phase was much smaller during rice chewing than pellet chewing. The jaw movements during rice chewing had smaller amplitudes of the gape and lateral excursion of the jaw as compared with those during pellet chewing. The SG muscle had a double-peaked burst activity in each masticatory cycle with one peak during the Op phase (the SG1 burst) and the other during the Cl phase (the SG2 burst). They were significantly larger during pellet chewing as compared with rice chewing, but the duration of the SG2 burst was significantly longer during rice chewing than pellet chewing. The offset of the SG2 burst was delayed during rice chewing as compared with that during pellet chewing. There was little difference in the activity pattern of the GG burst between the foods. Our present results suggest that the SG muscle activity could be modified by the sensory feedback possibly to adapt to environmental demands during chewing.

Extrinsic tongue and suprahyoid muscle activities during mastication in freely feeding rabbits.

To evaluate the coordination of tongue and suprahyoid muscle activities during natural mastication, electromyograms (EMGs) of jaw-closer, jaw-opener, suprahyoid (mylohyoid, MH), tongue-retractor (styloglossus, SG) and tongue-protractor (genioglossus, GG) muscles were recorded as well as the jaw-movement trajectories in vertical and horizontal axes in awake rabbits. Each masticatory cycle had three components including the fast-closing (FC), slow-closing (SC) and opening (Op) phases. The duration of the SC phase was much longer during pellet chewing while the durations of the FC and Op phases were much shorter during pellet chewing than bread or banana chewing. The jaw movements during banana chewing had a small amplitude of lateral excursion and a large amplitude of gape as compared with those during pellet and bread chewing. The MH muscle exhibited double-peaked EMG bursts during the Op phase. The MH bursts in the late part of the Op phase were dominant on the non-chewing side during pellet and bread chewing. The SG muscle also exhibited double-peaked EMG bursts. During pellet and bread chewing, the SG bursts during the SC phase were significantly larger on the chewing side than the non-chewing side. These bursts were also dominant during pellet chewing as compared with banana chewing. There was little difference in the GG bursts between the chewing and non-chewing sides or among the foods. Our results suggest that patterns of the MH and SG muscle activity are affected by the peripheral inputs and/or chewing patterns while those of the GG muscle activity was less modulated regardless of the consistency of foods.

Coordination of jaw and extrinsic tongue muscle activity during rhythmic jaw movements in anesthetized rabbits.

To clarify the jaw-closer and tongue-retractor muscle activity patterns during mastication, electromyographic activity of the styloglossus (SG) as a tongue-retractor and masseter (Mass) as a jaw-closer muscles as well as jaw-movement trajectories were recorded during cortically evoked rhythmic jaw movements (CRJMs) in anesthetized rabbits. The SG and Mass muscles were mainly active during the jaw-closing (Cl) phase. The SG activity was composed of two bursts in one masticatory cycle; one had its peak during the jaw-opening (Op) phase (SG1 burst) and the other during the Cl phase (SG2 burst). The Mass activity during the Cl phase was dominant on the working side (opposite to the stimulating side) while the SG1 and SG2 bursts were not different between the sides. When the wooden stick was inserted between the molar teeth on the working side during CRJMs, the facilitatory effects on the SG1 and SG2 bursts on both sides were noted as well as those on the Mass bursts, but the effects on the SG1 burst seemed to be weak as compared with those on the Mass and SG2 bursts. The difference in the burst timing between the sides was noted only in the SG1 burst. When the trigeminal nerves were blocked, the peak and area of the SG and Mass burst decreased during CRJMs, and the facilitatory effects of the wooden stick application on the muscles were not noted. The results suggest that the jaw and tongue muscle activities may be adjusted to chew the food and make the food bolus.

Effects of the inferior alveolar nerve stimulation on tongue muscle activity during mastication in freely behaving rabbits.

Genioglossus (Gg) reflexes elicited by electrical stimulation of the inferior alveolar nerve were examined in naturally chewing rabbits. To eliminate possible contaminations of the digastric (Dig) activity in the Gg responses, the Dig nerve was denervated bilaterally. Masticatory and tongue muscles were well coordinated during chewing after the denervation; i.e., there were no significant differences in the phase durations between before and after denervation. The Gg reflex measured was divided into three categories depending on the chewing phase (i.e., jaw-opening, OP; fast-closing, FC; and slow-closing, SC) in which the stimulus was delivered. The reflex amplitude was phasically modulated for the phases, in that the amplitude in the OP phase was larger than that in any other phase (P<0.05). On the other hand, the amplitude in the FC and SC phases was not significantly different to each other and from the control value obtained when the animal was awake and resting. The pattern of the modulation in the reflex amplitude was different from the previous report as to the Dig reflex in that OP