Autologous versus prosthetic nasal and auricular reconstruction - patient, professional and layperson perceptions.

The aim of this study was to retrospectively evaluate the perceptions of aesthetic outcome following the autologous and prosthetic reconstruction of nasal and auricular defects among patients, professionals (oral and maxillofacial surgeons and ear, nose and throat surgeons) and people unfamiliar with reconstructive surgery. The influence of anatomical subunits on the overall perception of nasal and auricular reconstructions was also determined. A total of 119 patients treated for nasal and auricular defects between 1997 and 2016, with a minimum follow-up period of 6 months, were selected, and photographs of 77 of these patients (65%) were presented in a digital survey and reviewed using a standardized questionnaire. No clinically relevant correlations were found between the age or gender of patients (as well as those of the respondents) and their scores. Prosthetic reconstructions of nasal and auricular defects were considered advantageous over autologous reconstructions in terms of the subjective aesthetic outcome in the view of the professionals, in particular oral and maxillofacial surgeons; however, the patients judged both techniques to be equally effective in terms of aesthetics. No anatomical subunits were found to have a significant impact on the overall match of a nasal or auricular reconstruction with the patient's face.

Do the changes in muscle mass, muscle direction, and rotations of the condyles that occur after sagittal split advancement osteotomies play a role in the aetiology of progressive condylar resorption?

Changes in cross-sectional area (CSA), volume (indicating muscle strength), and direction of the masseter and medial pterygoid muscles after surgical mandibular advancement were measured, along with the rotation of the condyles after bilateral sagittal split osteotomies (BSSOs) to advance the mandible. Measurements were done on magnetic resonance images obtained before and 2 years after surgery. CSA and volume were measured in five short-face and seven long-face patients (five males, seven females). Muscle direction was calculated in eight short-face and eight long-face patients (eight males, eight females). Short-face patients underwent BSSO only; long-face patients underwent combined BSSO and Le Fort I osteotomies. The CSA and volume decreased significantly (mean 18%) in all patients after surgery. The postoperative muscle direction was significantly more vertical (9°) in long-face patients. Rotations of the proximal segments (condyles) were minimal after 2 years. The results of this study showed that, after BSSO advancement surgery, changes in the masseter and medial pterygoid muscles are not likely to cause increased pressure on the condyles and nor are the minimal rotations of the condyles. It is concluded that neither increased muscle traction nor condylar rotations can be held responsible for progressive condylar resorption after advancement BSSO.

Static and dynamic loading of mandibular condyles and their positional changes after bilateral sagittal split advancement osteotomies.

This study analysed the effects of change of direction of masseter (MAS) and medial pterygoid muscles (MPM) and changes of moment arms of MAS, MPM and bite force on static and dynamic loading of the condyles after surgical mandibular advancement. Rotations of the condyles were assessed on axial MRIs. 16 adult patients with mandibular hypoplasia were studied. The mandibular plane angle (MPA) was <39° in Group I (n=8) and >39° in Group II (n=8). All mandibles were advanced with a bilateral sagittal split osteotomy (BSSO). In Group II, BSSO was combined with Le Fort I osteotomy. Pre and postoperative moment arms of MAS, MPM and bite force were used in a two-dimensional model to assess static loading of the condyles. Pre and postoperative data on muscle cross-sectional area, volume and direction were introduced in three-dimensional dynamic models of the masticatory system to assess the loading of the condyles during opening and closing. Postsurgically, small increases of static condylar loading were calculated. Dynamic loading decreased slightly. Minor rotations of the condyles were observed. The results do not support the idea that increased postoperative condylar loading is a serious cause for condylar resorption or relapse.

Positional changes of the masseter and medial pterygoid muscles after surgical mandibular advancement procedures: an MRI study.

This study evaluated whether surgical mandibular advancement procedures induced a change in the direction and the moment arms of the masseter (MAS) and medial pterygoid (MPM) muscles. Sixteen adults participated in this study. The sample was divided in two groups: Group I (n=8) with a mandibular plane angle (mpa) <39° and Group II (n=8) with an mpa >39°. Group I patients were treated with a bilateral sagittal split osteotomy (BSSO). Those in Group II were treated with a BSSO combined with a Le Fort I osteotomy. Pre- and postoperative direction and moment arms of MAS and MPM were compared in these groups. Postsurgically, MAS and MPM in Group II showed a significantly more vertical direction in the sagittal plane. Changes of direction in the frontal plane and changes of moment arms were insignificant in both groups. This study demonstrated that bimaxillary surgery in patients with an mpa >39° leads to a significant change of direction of MAS and MPM in the sagittal plane.