Recording of S Vit D, USG, and sEMG
PAD, PATHOLOGY, CONTRACTION
Measurement of S Vit DThe institute’s medical pathology laboratory support was taken for the test. The trained technician blinded from the study collected the blood sample from each subject. The liquid chromatography-tandem mass spectroscopy (LC-MS) was applied for the direct measurement of 25(OH)D [25-hydroxyvitamin D] in the serum. The Vit-D levels were expressed in ng/mL [sEMG of masseter musclesEMG of the masseter muscle was done with surface electrodes, using surface electromyography apparatus (NeuroStim Ultra, NeuroStim Ultra series Machine, EMG-2000 series; Medicaid Systems, Mohali, Punjab; India) available in the institute pathology department. Surface electromyography (sEMG) is a form of measurement of the masticatory muscles’ functionality, able to identify variations of the electric potential of the muscles during each performed contraction, both in chewing and swallowing [All sEMG tests were performed by the same technician as the chief researcher both of them had been calibrated for the same. Prior to each sampling, site friction with non-sterile gauze soaked in 70% alcohol was performed in order to minimize artifacts and improve signal capture. The reference electrode (earth) was placed in the front portion of the patient’s head. Data were obtained on the electrical activity of the masseter muscle group during the tasks of rest and maximum clenching (with maximum bite force, MBF). The records were collected by MBF, maintained for 5 s, and repeated three times with a 1 min interval addition to rest between each collection. The average was used for signal normalization, equivalent to 100% of the electrical activity. The signals collected during mastication were analysed by Root Mean Square (RMS) and expressed in microvolts (uV) [USG of Masseter muscleAll scans were carried out in the ultrasonography department. Each subject was examined by the same operator using the Thei Style Ultrasound system with a 7.5–9.0 MHz broadband transducer. A line was drawn joining the lateral commissure of the mouth to the intertragic notch (space that separates the tragus from the antitragus in the outer ear) of the ear, crossing the masseter muscle. A generous amount of water-soluble conductive gel was applied evenly on the muscle area on the cheeks using a gauze pad. The ultrasound probe was placed on the line with a feather-like pressure. The angle of the probe was adjusted to produce the strongest echo from the mandibular ramus, which was achieved when the scan plane was perpendicular to its surface. The imaging and measurements were performed bilaterally with the subjects in a supine position under two different conditions: when the teeth were gently occluding with the muscle in a relaxed position and during maximal clenching, with the masseter muscle contracted. The measurements were made directly from the image at the time of scanning [Each measurement was recorded twice at an interval of 1 h and the average value was considered for analysis. The three levels of S Vit D, USG measured muscle thickness, and sEMG measured muscle activity was paired values as they are the before and after values of an intervention. A thorough analysis was conducted.As far as the use of a repeated measures mixed model is concerned, we would like to admit that S Vit D levels over a period of 6 months are not dependent upon the vitamin D supplementation alone but are also dependent on a host of other factors such as season, dietary intake, level of sun exposure, etc., and hence it is not desirable to study this multifactorial model without considering all these factors.