Objective

  The objective of this study was to investigate differences in masseter metabolism by 31P-Chemical Shift Imaging (CSI) in adult individuals with different vertical facial patterns. The clinical study should be supported by functional findings at the mRNA level after orthognathic surgery.

 Study Design

  Twenty-two male volunteers (mean age 24.6) were divided into a deep-bite (NL/ML 11.8 ± 2.3°) and open-bite group (NL/ML 34.1 ± 2.6°). Vertical jaw relationship, gonial angle, and masseter volume were defined and compared with the phosphate values obtained from the 31P spectra. Student t test and regression analysis were used.

 Results

 Phosphocreatine related strongly to muscle volume (P < .001), gonial angle (P < .001), and ML/NL angle (P < .01). Pi was found to be related to gonial angle (P < .05). Muscle volume was found to be inversely related to ML/NL (P < .01) and to the gonial angle (P < .01).

 Conclusions

  A difference in masseter muscle metabolism between long- and short-faced subjects was confirmed at rest position.

 Source: Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology

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