Resection of the quadrangular lobule of the cerebellum to increase exposure of the cerebellomesencephalic fissure: an anatomical study with clinical correlation.

OBJECTIVE: The lateral aspect of the cerebellomesencephalic fissure frequently harbors vascular pathology and is a common surgical corridor used to access the pons tegmentum, as well as the cerebellum and its superior and middle peduncles. The quadrangular lobule of the cerebellum (QLC) represents an obstacle to reach these structures. The authors sought to analyze and compare exposure of the cerebellar interpeduncular region (CIPR) before and after QLC resection and provide a case series to evaluate its clinical applicability. METHODS: Forty-two sides of human brainstems were prepared with Klingler's method and dissected. The exposure area before and after resection of the QLC was measured and statistically studied. A case series of 59 patients who underwent QLC resection for the treatment of CIPR lesions was presented and clinical outcomes were evaluated at 1-year follow-up. RESULTS: The anteroposterior surgical corridor of the CIPR increased by 10.3 mm after resection of the QLC. The mean exposure areas were 42 mm2 before resection of the QLC and 159.6 mm2 after resection. In this series, ataxia, extrapyramidal syndrome, and akinetic mutism were found after surgery. However, all these cases resolved within 1 year of follow-up. Modified Rankin Scale score improved by 1 grade, on average. CONCLUSIONS: QLC resection significantly increased the exposure area, mainly in the anteroposterior axis. This surgical strategy appears to be safe and may help the neurosurgeon when operating on the lateral aspect of the cerebellomesencephalic fissure.

Interdisciplinary management of an impacted dilacerated maxillary central incisor

ABSTRACT Introduction: Tooth dilacerations are dental anomalies characterized by an abrupt deviation in the longitudinal axis of a tooth. They may occur either in the crown, between the crown and root, or in the root. Although not so common, impacted maxillary incisors exhibiting root dilaceration pose a diagnostic and treatment challenge to the clinician. Description: This case report describes the management of a horizontally impacted and dilacerated maxillary central incisor in a 12-year-old girl. Cone-beam computed tomographic scans were used to accurately localize the position of the dilacerated tooth, and to assess the extent of root formation and degree of dilaceration present in the root. Treatment included surgical exposure and orthodontic traction, followed by root canal treatment and apicoectomy. Results: Through a meticulously planned interdisciplinary approach, the impacted dilacerated central incisor was properly aligned and demonstrated good stability after the long-term follow-up. Conclusion: Taking into consideration the concerns and expectations of the patient, communicative feedback between the oral surgeon, orthodontist and endodontist helped achieving successful esthetic, structural and functional outcome in the present case.

RESUMO Introdução: as dilacerações dentárias são anomalias caracterizadas por desvio acentuado no eixo longitudinal de um dente. Elas podem ocorrer na coroa, entre a coroa e a raiz, ou na raiz. Apesar de não serem muito comuns, os incisivos superiores impactados apresentando dilaceração radicular representam um desafio para o clínico, quanto ao diagnóstico e tratamento. Descrição: o presente relato de caso descreve o tratamento de um incisivo central superior impactado horizontalmente e com dilaceração, em uma menina com 12 anos de idade. Tomografias computadorizadas de feixe cônico foram utilizadas para localizar com precisão a posição do dente dilacerado e avaliar o grau de formação e de dilaceração da raiz. O tratamento incluiu exposição cirúrgica e tração ortodôntica, seguida de tratamento do canal radicular e apicectomia. Resultados: por meio de uma abordagem interdisciplinar meticulosamente planejada, o incisivo central impactado com dilaceração foi devidamente alinhado e demonstrou boa estabilidade em acompanhamento de longo prazo. Conclusão: levando-se em consideração as preocupações e expectativas da paciente, a comunicação interativa adotada entre o cirurgião oral, ortodontista e o endodontista ajudou na obtenção de resultados estéticos, estruturais e funcionais satisfatórios no presente caso.