Relationship between the angle of the coronoid process of the mandible and the electromyographic activity of the temporal muscle in skeletal Class I and III individuals

Abstract

The aim of the present study was to verify the relationship between the angle of the coronoid process of the mandible in the latero-lateral direction and electromyographic activity of the anterior part of the temporal muscle in skeletal Class I and III individuals. Forty-five volunteers were assessed subdivided into two groups, according to angle ANB, in Class I and III. Two radiographic examinations were performed, one lateral cephalogram to measure angle ANB and one frontal cephalogram to measure the angle of the coronoid process. The electromyographic examination of the volunteers' temporal muscles was performed. Statistical analysis of the data showed that the relationship between the angle of the coronoid process and the skeletal class was negative for both classes analysed. The relationship between electromyographic activity of the temporal muscle and angle of the coronoid process was negative for Class I individuals. In the Class III group, smaller angles of the coronoid process were related to higher values of electromyographic activity of the temporal muscle. There was no statistically significant difference between the electromyographic activity of the temporal muscle in skeletal Class I and III individuals. Based on the results obtained, it was concluded that there was no influence of the skeletal classes analysed on the angle of the coronoid; the angle of the coronoid process may be influenced by the electromyographic activity of the temporal muscle in the Class III group; the electromyographic activity of the temporal muscle is not influenced by the skeletal class in Class III individuals.

FGF and TGFβ signaling link form and function during jaw development and evolution

“…Thus, the evolutionary presence or absence of secondary cartilage on the coronoid process reflects species-specific variation in functional anatomy determined by in ovo mechanical loading (Beresford, 1981; Fang and Hall, 1997; Hall, 1979; Stutzmann and Petrovic, 1975). In taxa such as humans, rats, cats, and duck, secondary cartilage forms at the jaw adductor muscle insertion (Amorim et al, 2010, 2008; Hall, 2005; Horowitz and Shapiro, 1951; Kantomaa and Rönning, 1997; Moore, 1973, 1981; Solem et al, 2011; Soni and Malloy, 1974; Vinkka, 1982; Washburn, 1947) whereas an equivalent secondary cartilage is absent in mice, guinea pigs, chick, and quail (Anthwal et al, 2008, 2015; Boyd et al, 1967; Moss and Meehan, 1970; Rot-Nikcevic et al, 2007; Shibata et al, 2003; Solem et al, 2011). Our work implies that the reason secondary cartilage forms at this location in some species and not others is due to the way embryonic motility interacts with NCM-mediated muscle pattern to create differential forces.…”

Mandibula processus coronoideus morfometrik parametrelerinin taraflar arası incelenmesi

“…At the beginning of the prenatal period, the height of ramus of mandible increases more than LBM, and the rate of increase becomes equal towards the end (19). The relationship between mandible and TM begins in the prenatal period and continues in the postnatal period (2,4,6,7,10,11).…”

“…TCP increase in patients with CP hyperplasia. It has also been shown that there is early contact between zygomatic arc and CP (10). It may cause trismus due to an increase in HCP or a change in CP direction (10).…”

“…It has also been shown that there is early contact between zygomatic arc and CP (10). It may cause trismus due to an increase in HCP or a change in CP direction (10). It has been reported that physical therapy is not beneficial in cases of CP hyperplasia, but surgical treatment is possible (17).…”

“…In addition, CP is particularly associated with morphological structures on ramus of mandible, and these differ between individuals (1, 3, 7-9). Studies in literature have shown that changes in TM function and gonial angle (GA) affect CP (2,4,6,7,10,11). It has been reported that angle of mandibular notch (AMN) formed between CP and CnP is higher in women (12) and it is wider on right side (9).…”