ABSTRACT
The implant-prosthetic rehabilitation of edentulous upper jaws has always been complex for surgeons and dentists. The lack of bone in both vertical and horizontal dimension does not allow the correct insertion of dental implants. In addition, patients with edentulous upper and lower arch have a loss of vertical dimension of the face and an aged expression. Many surgical techniques have been proposed to increase the bone volume, height and thickness, such as the Le Fort I osteotomy, the bone grafts and the placement of dental implants. Planning these surgical procedures is difficult, because it is not possible to reproduce the movements of osteotomized bone segments in three planes of space. This article describes the treatment of severe atrophy maxilla with a new approach using a new instrument named "Surgiplanner". Surgiplanner is a method that, only using a computerized axial tomography (CAT), allows to obtain a totally predetermined therapeutic result from both an aesthetic and functional point of view, with surgery of severe resorbed jaws. Surgiplanner allows repositioning of segment of the skeleton of the patient's face in a predetermined and controlled way for the best implant-supported oral rehabilitation.
ABSTRACT
PURPOSE: We have tried to demonstrate whether the analysis of the muscle strain allows us to identify the three distinct functional areas of the architecture of the masseter, as one would see them by performing or viewing an anatomical dissection of said muscle, and whether these sections have behave differently in terms of origin and coping of the strain they face (quantitative analysis). MATERIALS AND METHODS: This work has been elaborated by the use of an ultrasound machine (MicrUs ext-1H Telemed Medical Systems Milano) and a linear probe (L12-5l40S-3 5-12 MHz 40 mm) which allowed us to record a 45 frame per second video (DCM). Videos has been elaborated by use of an ultrasound machine (MicrUs ext-1H Telemed Medical Systems Milano) and a linear probe (L12-5l40S-3 5-12 MHz 40 mm) which allowed us to record a 45 frame per second video (DCM). We applied to the resulting video a software (Mudy 1.7.7.2 AMID Sulmona Italy) for the analysis of muscle deformation patters (contraction, dilatation, cross-plane, vertical strain, horizontal strain, vertical shear, horizontal shear, horizontal displacement, vertical displacement). The number of videos of masseter muscles in contraction at maximum exertion due to dental clenching made during this research is around 12,000. Out of these we chose 1,200 videos which examine 200 patients (100 females, 100 males). RESULTS: The deformation pattern analysis of the skeletal muscle on ultrasound basis seems to be an adequate instrument to use during the investigation of the functional structure of the masseter muscle given its ability to highlight the distinct activity of each separate part of the muscle. CONCLUSIONS: Moreover the strain does not apply to the muscle uniformly; instead it varies according to the observed area.
ABSTRACT
PURPOSE: The objective of the following study is to observe the behavior of the six layers of the masseter during an isometric contraction at maximum exertion with the deformation pattern analysis method. MATERIALS AND METHODS: This study has been conducted by use of an ultrasound machine (MicrUs ext-1H Telemed Medical Systems Milano) and a linear probe (L12-5l40S-3 5-12 MHz 40 mm) which allowed us to record a video (DCM) comprised of 45 frames per second. The probe was fixed to a brace and the patient was asked to clench their teeth as hard as possible, obtain the muscle's maximum exertion, for 5 seconds three times, with 30 seconds intervals in between. Both right and left masseter muscles were analyzed. Then we applied to the resulting video a software (Mudy 1.7.7.2 AMID Sulmona Italy) for the analysis of muscle deformation patterns (contraction, dilatation, cross-plane, vertical strain, horizontal strain, vertical shear, horizontal shear, horizontal displacement, vertical displacement). The number of videos of masseter muscles in contraction at maximum exertion due to dental clenching made during this research is around 12,000. Out of these we chose 1,200 videos which examine 200 patients (100 females, 100 males). RESULTS: The analysis of the deformation patterns of the masseter allows us to observe how the six layers of the muscle have different and specific functions each, which vary depending on the applied force (application point, magnitude and direction) so that we find it impossible to assign to one of the three sections of the muscle a mechanical predominance. Therefore it appears that the three parts of the muscle have specific and synergistic tasks.
ABSTRACT
PURPOSE: The aim of the following study is to examine both masseter muscles (left/right) in a group of patients suffering from unilateral chewing during a maximum exertion isometric contraction using the deformation pattern analysis of ultrasound videos and compare them with the results obtained by studying patients with alternate bilateral chewing patterns. MATERIALS AND METHODS: This study has been conducted by use of an ultrasound machine and a linear probe which allowed us to record a video (DCM) comprised of 45 frames per second (MicrUs ext-1H Telemed Medical Systems Milano) and a linear probe (L12-5l40S-3 5-12 MHz 40 mm). The probe was fixed to a brace and the patients were asked to clench their teeth as hard as possible, obtain the muscle's maximum exertion, for 5 seconds three times, with 30 seconds intervals in between. Both right and left masseter muscles were analyzed. We applied to the ultrasound video a dedicated software (Mudy 1.7.7.2 AMID Sulmona Italy) for the analysis of muscle deformation patterns. The total number of patients for this study is 150. Out of this number, 50 belong to Group A, mono lateral chewing on the left side arch, and 50 to Group B, mono lateral chewing on the right side arch. The remains patients belong to Group C, bilateral alternate chewing. The deformation pattern analysis of the skeletal muscles on ultrasound videos allows us to highlight with ease the clear difference in the clenching capabilities and strain management between the dominant masseter and the subordinate masseter in a unilaterally chewing patient. RESULTS: In the sample investigated both in Group A and Group B the unilateral chewing is associated with a series of parameters (number, shape, volume, position and orientation of the teeth) and is also associated with the extension of the cutting surface really available.
ABSTRACT
The masseter muscle represents an area of important functional interest. The present study aims to verify the feasibility of ultrasound imaging for quantifying the muscular deformation pattern in the masseter. Fifteen consecutive subjects were enrolled and underwent masseter ultrasound according to a repeatable protocol. Ultrasound was carried out during teeth clenching in natural conditions and after the insertion of a medical device that alters the distance between the dental arches, and was repeated on 3 different days. Results showed that masseter deformation is not uniform within the muscle. The same strain patterns were repeated in the different ultrasounds of the same patient and were modified after the introduction of a medical device. This was supported by quantitative comparisons in the deep portion of the muscle (standard deviation on the three measures: 3% normal conditions, 2% with medical device) showing a systematic reduction with the prosthesis (30% on average). This study demonstrated that masseter strain analysis is a repeatable and sensitive tool for the study of functional analysis of the masticatory organ. This opens new technical perspectives for the diagnosis and therapy of dysfunctional pathologies of the masticatory organ.
