1. Department of Neurosurgery, The Center for Advanced Neurology and Neurosurgery (CEANNE), Porto Alegre, Brazil
2. Postgraduate Program in Principles of Surgery, Mackenzie Evangelical College of Paraná, Curitiba, Brazil
3. Department of Oral & Maxillofacial Surgery and Periodontology, School of Dentistry of Ribeirão Preto at University of São Paulo, Ribeirão Preto, Brazil
4. Department of Pathology, Moinhos de Vento Hospital, Porto Alegre, Brazil
5. Department of Anatomy, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
6. Department of Neurotology, The Center for Neurotology and Acoustic Neuromas (CNNA), Porto Alegre, Brazil