Biomedical subjects

Max Domingues Pereira

Publications and source records attributed to Max Domingues Pereira.

4 recordsLinked to original sources

PubMed2006

The composition and behavior of capsules around smooth and textured breast implants in pigs.

BACKGROUND: The surface of the implant is one of the many factors often associated with the occurrence of capsular contracture, the etiopathogeny of which remains unclear. The purpose of this study was to analyze the behavior of capsular contracture by means of applanation tonometry and histology using a midsized animal model. METHODS: Silicone breast implants were implanted into 33 pigs and observed at 30, 60, 180, and 270 postoperative days. RESULTS: Capsular contracture in smooth implants showed significantly greater pressure values of tonometry, and the smooth implant capsule was significantly thicker than the textured implant capsule. Both pressure and thickness of the capsules increased at each period. The collagenous layer did not show any difference considering the periods of time in which the total thickness was analyzed; on the other hand, the increase in total capsular thickness occurred by thickening of the noncollagenous layer in both smooth and textured implants. Taking into consideration both kinds of implants, histomorphometric analysis showed that thin fibers were replaced by thick fibers in later postoperatives periods (180 and 270 days). CONCLUSIONS: The greater incidence of capsular contracture in smooth implants was correlated with the progressive increase in total capsule thickness, due to a higher concentration of collagenous fibers, when compared with textured implants (p = 0.011; mean difference, 6.61), and a higher concentration of thick fibers (p = 0.034; average, >5.51 percentage points per field of thick fibers than the textured implants in all periods). Pigs are good animal models for studying the healing process after breast augmentation with implants.

Animals↗

PubMed2003

[Evaluation of condylar fractures treatment].

BACKGROUND: We analysed 40 patients with mandibular condylar process fractures, treated through the closed (intermaxilary fixation or conservatively) or open methods (wire internal fixation,titanium miniplates, bone reduction or articular exploration), from January 1993 to January 1999. METHODS: We evaluated these patients clinically with pre-determined criteria through the temporomandibular articulation touching (ATM), by observing the mandibular symmetry, dental oclusion, deviation to the mouth opening and maximum interincisal opening, besides the questionnaire about the complaints at ATM, disfunction of the mastication system and satisfaction of the treatment. We found an index of good clinical results of, at least, 70% (in the maximum interincisal opening) in the patients submitted to IMF. In the conservative method, we found an index of, at least, 42.9% and in the patients submitted to wire open reduction, at least, 28.6% (in the ATM touching exam) without significant difference in the clinical exams; the pain index at ATM in the closed method was 3.7% and in the open one was 15.4%; mastication disfunction was 22.2% in the closed method and 15.4% in the open one; we only found 7.1% dissatisfied patients in the closed method. There was no significant difference in the method results. CONCLUSIONS: The closed method - with IMF and conservative - and the open reduction - with ORIF - brought good clinical results in an evaluation up to 6 months. We could also conclude that there is no difference in the complaint results after the open or closed treatment according to the patients' opinion.

Adolescent↗

PubMed2003

Three-wall decompression technique using transpalpebral and endonasal approach in patients with Graves' ophthalmopathy.

PURPOSE: To evaluate the effects of the three-wall decompression technique using transpalpebral and endonasal approach in patients suffering from Graves' ophthalmopathy. METHODS: In this prospective study, we present a consecutive series of 15 subjects (17 eyes) who were submitted to orbital decompression by removing the inferior and lateral walls using transpalpebral incision combined with a transnasal endoscopic resection of the medial wall. The surgical technique involved the preservation of the bone structure between the lamina papyracea of the ethmoid and the maxillary orbital floor. MAIN RESULTS: The mean ocular recession based on Hertel measurements was 6.00 mm (range, 4-9 mm). None of the patients presented pre-operation diplopia, and one developed post-operation diplopia. Visual acuity was preserved in all cases. CONCLUSION: It is safe and efficient to perform three-wall decompression, combining transpalpebral and endoscopic transnasal approach, with preservation of the bone structure and the bone lateral to the infraorbital canal with fixation by two titanium plates on the lateral edge and removal of intraorbital fat, which results in significant proptosis reduction and minimal complications.

Adult↗

PubMedDate not supplied

[Exenteration: a retrospective study].

PURPOSE: To review all cases of orbit exenteration performed at the Orbit Sector, Ophthalmology Department - Federal University of São Paulo, from 1998 to 2003. METHODS: We reviewed conditions leading to orbital exenteration in 21 patients at the Orbit Sector of Unifesp-EPM from August 1998 to May 2003. Data regarding sex, age, race, primary lesion site, visual acuity at the moment of diagnosis, previous surgeries related to the exenteration, type of performed surgery, histopathologic diagnosis, postoperative complications and use of adjuvant treatment were collected. RESULTS: 21 patient charts were retrospectively analyzed. Ages ranged from 5 to 91 years (mean of 58.5 years). Of these, 12 were male and 9 were female, most of them Caucasian. All lesions that led to exenteration were malignant neoplasias; however, none were metastatic. Lesions originated from eyelids in twelve patients, from bulbar conjunctiva in six and from the orbit in three. Cases were also classified as squamous cell carcinoma (eleven cases), basal cell carcinoma (four cases), sebaceous gland carcinoma (two cases), rhabdomyosarcoma (two cases), mucoepidermoid carcinoma (one case) and adnexal microcistic carcinoma (one case). Visual acuity at the moment of diagnosis ranged from 20/40 to no light perception. Only six patients had been submitted to previous surgeries related to the exenteration. After surgery, three patients suffered graft necrosis, one presented ethmoidal sinus fistula to the orbit and one presented orbital socket shrinkage. Six patients needed postoperative radiotherapy and two had been previously submitted to chemotherapy. CONCLUSION: Most patients analyzed in our study presented lesions that are usually small in the beginning; however, they can disseminate to the orbit in the absence of adequate treatment.

Adolescent↗