The recording and analysis of EMG and jaw tracking. II. reproducibility of jaw tracking

Abstract

In 10 male and 10 female adults jaw movements and muscle activity were monitored during chewing. Subjects had a Class I occlusion and fluent unrestricted jaw movements; non exhibited signs or symptoms of craniomandibular disorders. Recordings were made on two occasions separated by 2 weeks. Within each recording session the subjects carried out a number of tasks under direction, including eating nuts and gum. The jaw movements were monitored with a Sirognathograph which had been interfaced to a computer for data logging and analysis. A computer program identified each chewing stroke and after scrutiny a data base was constructed of measurements from a subset of 4447 suitable strokes. Mean values of 10 parameters selected to describe jaw movements during chewing were entered into an ANOVA. This indicated that the major contribution to variance was due to the subject from whom the data was recorded. This intersubject variability is well known, but can its separation from the other contributions to the variation within the data be assessed? To provide an estimate of the spread of data the variance for each parameter was calculated, transformed and these values entered into an analysis of variance. All subject differed significantly in their chewing movements from one another. But 15 of the 20 subjects showed a greater degree of consistency than the other five: they exhibited good inter- and intra-recording reproducibility. The food being eaten made a major contribution to the variability. The timing of the chewing strokes was also more consistent than the dimensions of the chewing envelope.

Mandibular Kinematics in Patients With Alloplastic Total Temporomandibular Joint Replacement—A Prospective Study

“…The replacement of the jaw-tracking system at different examination times (T0, T1, T2, and T3 in the present study) produced only a small influence on the results. [19][20][21] Yoon et al 21 investigated the differences in mean condyle LD and CP in trial sessions in the same individuals using an electromagnetic tracking device. The condylar LD was reported to vary from 16.1 Ϯ 6.1 mm (right condyle) or 15.4 Ϯ 4.1 mm (left condyle) in the first trial session to 13.3 Ϯ 5.2 mm (right condyle) or 12.7 Ϯ 4.0 mm (left condyle) in the retest trial session.…”

“…18 The reproducibility of jaw-tracking systems is believed to be reliable. [19][20][21] The mandibular clutch was individually customized on the labial surfaces of the lower anterior teeth using a provisional autopolymerizing cold-cure acrylic (Structur Premium, Voco, Cuxhafen, Germany) and fastened using a tissue adhesive (Histoacrylic, B Braun GmbH, Tuttlingen, Germany). The horizontal reference plane for the analysis system included the kinematic center of the right and left condyles posteriorly and the orbitale anteriorly, which was defined before registration by the digitization of the 3-dimensional coordinates of a patient's anatomic orbitale of the left eye and the lateral palpated poles of the 2 condyles with the help of a probe tip.…”

Relevance of mandibular helical axis analysis in functional and dysfunctional TMJs

“…Masticatory movements are influenced by consistency, dimension and texture of the food (Hannam et al, 1977;Gibbs et al, 1981;Thexton, 1992;Howell et al, 1993;Takada et al, 1994;Palla et al, 1997). For instance, tough food is chewed with wider lateral excursions than soft food.…”

Using dairy ingredients to alter texture of foods: Implications based on oral processing considerations

“…These parameters can be analyzed for complete sequence or different parts of the chewing sequence such as initial cycles, middle cycles, and last cycles (Brown et al, 1998a;Lassauzay, Peyron, Albuisson, Dransfield, & Woda, 2000;Peyron, Lassauzay, & Woda, 2002). Good reproducibility between inter-and intra-recordings of EMG analysis is reported by many researches (Brown, 1994;Ferrario & Sforza, 1996;Howell, Ellis, Johnson, Watson, & Klineberg, 1993;Peyron et al, 2002). These parameters provide information about how a food is processed in the mouth from first bite up to swallowing.…”