Roger Lanes Silveira

Bone tissue microscopic findings related to the use of diode laser (830etam) in ovine mandible submitted to distraction osteogenesis

PURPOSE To analyze the microscopic characteristics of the effect of Gallium-Aluminum Arsenid diode laser (GaAlAs - 830etam) applied during the activation and consolidation period to ovine mandibles submitted to distraction osteogenesis. METHODS Eighteen sheep underwent surgery in order to have bone distractors implanted in the left side of the jaw area. They were divided into three groups: 1 - Control; 2 - Laser irradiation during the activation period; 3 - Laser irradiation during the fixation period. The irradiation was carried out in five sessions, on every other day, with 4,0J/cm(2) doses applied to four pre-established areas, totaling 16J per session. After four days of latency under post-operative care, ten days of distractor activation (at 1mm/day) and twenty-one days of fixation the animals were sacrificed and the devices removed for microscopic analysis. RESULTS The groups that received laser irradiation (GaAlAs) presented a greater amount of mineralized bone trabeculae when compared to the Control Group. Despite that, cartilaginous tissues were also found in Group 2. CONCLUSION The laser has been more favorable when used in the consolidation period, after bone elongation.

Self-drilling and Self-tapping Screws: An Ultrastructural Study

Objective:The aim of the current study was to compare self-drilling and self-tapping screws with regard to bone contact and the production of bone debris using scanning electron microscopy. Materials and Methods:Three New Zealand rabbit calvariae were used. Self-tapping and self-drilling screws were inserted into the outer surface of the skull with and without saline solution irrigation. All screws were 5 mm in length and were inserted until their tips projected through the endosteal side. Sixteen screws were used-8 with a head diameter of 1.5 mm and 8 with 2.0 mm. All self-tapping screws were inserted through a drill bit hole (1.6 mm for 2.0-mm screws and 1.3 mm for 1.5-mm screws). Results:There was no damage to the screws after insertion. Bone damage occurred when irrigation was not used during the installment of the self-tapping screws. Bone debris formed during the installment of the self-drilling screws, which is considered beneficial. Conclusions:Because the insertion of self-drilling screws is performed with manual pressure, irrigation is not essential. Unlike the drilling that occurs with self-tapping screw, the bone debris formed with self-drilling screws is not the result of the heat generated, but rather the result of biologically active bone tissue capable of reacting with the screw and improving its performance. The animal model used proved highly appropriate for comparisons with human beings because the bone structures of the head have the same density and thickness.

Retrobulbar hemorrhage—Case report

Retrobulbar hemorrhage is a rare complication that may occur after mid-face injuries or following soft and hard tissue surgery around the eyes. The cardinal signs and symptoms of retrobulbar hemorrhage are pain, diplopia, ophthalmoplegia, a progression of increasing proptosis, and decreasing visual acuity leading to blindness. The diagnosis can be confirmed with computed tomography (CT) of the orbit or with ocular ultrasound. These diagnostic images are also important to define the size of the hematoma. This report describes a traumatic retrobulbar hemorrhage. In this case there were no signs of acute visual loss, and conservative treatment was possible without surgical intervention.

Osteoma Dérmico – Relato de Caso

O osteoma e uma lesao osteogenica benigna que pode ser contituida por osso compacto ou esponjoso. A etiologia parece ser desconhecida, muito embora diversos autores tenham sugerido determinadas origens para justificar sua elucidacao, entre as quais: congenita, infecciosa e traumatica. Esta lesao apresenta crescimento lento, podendo ser encontrada, normalmente, na regiao crâniofacial, podendo ocorrer, raramente, em outros ossos. O diagnostico e feito acidentalmente, uma vez que esta lesao nao e acompanhada de alguma queixa de dor. O presente estudo se refere a ocorrencia desta patologia em regiao dermica, achado que nao foi relatado ate entao na literatura cientifica. Um homem com 31 anos de idade, procurou o Servico Bucomaxilofacial queixando-se de edema indolor na face. A combinacao entre os achados clinicos e radiograficos fundamentou o diagnostico de osteoma em regiao zigomatica.