Purpose: This study was designed to apply alternative and innovative methods of measuring muscle
area, volume, structure, function and fibre orientation to a situation where adaptation of muscle is
pivotal to the success of a therapeutic approach.
Materials and Methods: Ten patients attending the combined orthodontic/orthognathic surgery clinic
at the Clitrofa – Centro Médico, Dentário e Cirúrgico, in Trofa - Portugal were tested according to the
following protocol:
a) Bite Training Machine: The occlusal contact area indicator was placed between the upper and lower
dental arch, and the subjects were instructed to bite as forcefully as possible for about 3 seconds. The
values were visualized in the dynamometer and the procedure was repeated after 10 minutes until the
patient felt comfortable.
b) Occlusal Force Diagnostic System: The system was placed between the upper and lower dental arch,
and the subjects were instructed to bite as forcefully as possible for about 3 seconds. The values were
registered (T0) and the procedure was repeated after 10 minutes (T1), and 1 month after surgery (T2).
In this study, the bite force and occlusal pressure were measured for 10 patients twice by two different
observers. These 10 patients were scheduled for a bimaxillary osteotomy involving a combination of
maxillary Le Fort I impaction procedure coupled with a sagittal split advancement of the mandible.
Conclusions: When comparing pre-op (Times 0 and 1) and post-op (Time 2) data, significant statistical
differences have been found in the mean bite pressure measured by FSS sensor Q3/P3 located in the
anterior region of the maxilla/ mandible (p < 0,05), those differences being absent in the remaining FSS
sensors Q1/P1, Q2/P2, Q4/P4 and Q5/P5 (p > 0,05). Significant differences (p < 0,05) have been identified
between certain pairs of FSS sensors, allowing the definition of a three-pressure region model where
the key-factor seems to be the relative distance of the sensors to the occlusion region: the higher the
distance to the occlusion region, the lower is the mean bite pressure (psi).
