The retromolar foramen represents a little known anatomical variation in the posterior mandible of uncertain clinical importance. It has been the subject of limited study. Findings and conclusions of these studies have been placed under little scrutiny. Suggested clinical consequences associated with the presence of the retromolar foramen include local anaesthetic failure, local haemorrhage during surgery, perineural spread of infectious and invasive pathology, and loss of sensation in the normal distribution of the buccal nerve due to surgical intervention. Reports of the possibility of these complications seem to suggest that the retromolar foramen, canal and its associated neurovascular bundle are structures of great clinical importance. Case reports seem to have, however, only included reports of loss of gingival and buccal sensation as a consequence of third molar surgery in the presence of this anomaly. This study therefore aimed to report the prevalence of the retromolar foramen and canal in the South African population, describe its course and structure, and produce a clinical framework in which to approach the presence of the retromolar foramen. Comparisons between the present and existing studies were made and conclusions concerning the clinical importance of this structure were drawn. Inspection of a sample containing 946 mandibles was performed. Of these, 885 were regarded as suitable for inclusion. These mandibles were inspected for the presence of a retromolar foramen in which a 1 mm diameter needle could pass through without resistance. The distance from the last tooth in the arch to the retromolar foramen was also measured. Fifty of these mandibles were then randomly selected and scanned using microfocus computed tomography. Seventy mandibles were found to have at least one retromolar foramen (7.9% of the total sample). No statistically significant differences were found when the presence of the retromolar foramen was correlated with race, sex or age. The finding that sex and age played no significant role in the presence of the retromolar foramen is in agreement with available literature. Detected prevalence seemed to be heavily influenced by the method used to determine the presence of the retromolar foramen. The average distance between the second mandibular molar and the retromolar foramen was 16.83 ± 5.57 mm and the average distance between the third mandibular molar and the retromolar foramen was 10.47 ± 3.77 mm. These findings were found to be in agreement with most other reports. Fifty retromolar canals were selected at random and scanned using microfocus computed tomography. Analysis revealed four basic patterns. These were type A, a vertical canal between the inferior alveolar canal and the retromolar area of the mandible, type B, a curved canal taking a recurrent course between the inferior alveolar canal and the retromolar area, type C, a canal with an approximately horizontal path between the inferior alveolar canal and the retromolar area, and the temporal crest canal (TCC, not designated as type D to create a distinction between it and types A, B and C), a canal terminating on either side of the temporal crest. Type B was the most common presentation (68% of retromolar canals in the study), a finding contrary to that of other studies. The presence of the retromolar neurovascular bundle is of uncertain clinical importance and requires further anatomical and pharmacological study to determine its effect on local anaesthetic failure. A model in which the retromolar canal branches from the inferior alveolar canal does not seem to support a conclusion in which local anaesthetic failure may be directly attributable the presence of this anatomical variation alone. Classification of the retromolar canal is of limited clinical use and may require a revised scheme if clinical application is sought. Complications associated with the presence of the retromolar foramen are poorly documented and seem to be of little consequence. / Dissertation (MSc)--University of Pretoria, 2014. / tm2015 / Anatomy / MSc / Unrestricted

Orientador: Krunislave Antonio Nobilo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-07-26T03:38:50Z (GMT). No. of bitstreams: 1 Oliveira_DeiseLucianePaiva_M.pdf: 3669508 bytes, checksum: 7bfb9a84147c2aa0208a3c91c1d26d0e (MD5) Previous issue date: 2000 / Resumo: Na construção de próteses totais e pistas deslizantes de Nóbilo são utilizados como referência para o plano Dclusal , o ponto anterior, ângulo entre os Incisivos Centrais Superiores e as papilas retromolares. Após mais de 20 anos de experiência clínica com excelentes resultados, esse trabalho objetiva determinar as correlações entre os planos de Camper e o plano oclusal de Nóbilo, entre o plano de Camper e o plano oclusal Natural, entre o plano de Nóbilo e o plano oclusal Natural verificando a validade da técnica utilizada. Selecionamos vinte e cinco pacientes dentados completamente, estando em dimensão vertical f.siológica, sem nunca terem se submetidos a tratamento ortodôntico. Os pacientes foram moldados. Os modelos foram confeccionados e analisados. Na arcada superior, colocou-se um dispositivo de resina acrflica ativada quimicamente com uma esfera de chumbo que guarda a localização do ângulo incisal entre os incisivos centrais superiores. Na arcada inferior também colocou-se um dispositivo com a mesma resina incluindo a esfera de chumbo que guarda a localização do centro, o ponto mais elevado da papila retromolar . Na face foram colocadas as esferas de chumbo sobre o ponto subnasal e tragus. Foram realizadas as teleradiografias, lado esquerdo e direito. Foram feitos os traçados cefalométricos e a análise entre o plano de Camper e o plano oclusal de Nóbilo; entre o plano de Camper e o plano oclusal Natural e entre o plano Nóbilo e o plano oclusal Natural, através de programa de Computação Gráfica Corei Draw. Os resultados obtidos permitiram concluir que a média de angulação encontrada entre o plano oclusal de Nóbilo e o Natural foi de 3,3297 o para o lado esquerdo e de 3,2742° para o lado direito; entre o plano de Camper e Nóbito foi de 5,2960° para o lado esquerdo e de 5,4013° para o lado direito; entre Camper e Natural foi de 1,9630° para o lado esquerdo e de 2,0127° para o lado direito, sendo que estatisticamente não houve diferença significativa entre os lados esquerdo e direito dos respectivos planos. O estudo da relação entre os planos de Camper e plano eclusal Natural nos permitiu a comparação com os valores da literatura que estão em média em torno de 5°, compatível com o tamanho das amostras. Dessa maneira, os valores obtidos nessa pesquisa estão mais próximos do paralelismo. O menor intervalo de confiança encontrado foi em relação ao plano de Nóbilo em relação ao Natural no valor de 0,77210 que determina uma menor variabilidade entre os indivíduos da amostra quando da análise desses planos. Verificou-se pelo teste Exato de Fisher a presença de 2% de plano oclusal reverso na análise entre o plano de Camper e Nóbilo, 4% em relação ao plano de Nóbilo e Natural e 30% em relação ao plano de Camper e Natural. O plano de Nóbilo pode ser adotado com segurança como referência, devido a sua menor variabilidade entre os indíviduos, pela baixa porcentagem de plano oclusal reverso, ou seja, pela sua reprodutibilidade / Abstract: The anterior mark, angle between the superior central incisors, and retromolar pad are used in the construction of total prostheses and NóbHo's gliding plates as reference to the occlusal plane. The aim of this work, after more than 20 years of clinical experience with excellents results, is to determine the correlation between Camper' plane and Nóbilo's occlusal plane, between Camper's plane and the Natural occlusal plane and between Natural occlusal plane and the Nóbilo's occlusal plane. Verifying then the validity of the technique that was used. We selected 25 pacients with complete dentition, in physiological vertical dimension, who had never submitted to an orthodontic treatment. The patients were molded. activated with a sphere of lead that keeps the incisal angle location between the The models were ma de and analysed. A device of Acrylic Resin chemically central superior incisors, was placed at the superior arcade. At the inferior arcade, a device with the same resin was also placed including the sphere of lead that keeps the central location the most elevated point of retromolar pad. On the face, spheres of lead were placed on the subnasal and tragus points. Radiographies were taken of both rtght and left sides. Also, cephatometric tracings and analysis were carried out between Camper's plane and Nóbilo's occfusal plane, between Camper's plane and the Natural ocelusal plane and between the Natural oeelusal plane and Nóbilo's oectusal plane by using Corei Draw, whieh is a graphie eomputer programo The results obtained after the statistical evaluation allowed us to eonelude that the mean angulation found was 3,3297° to left side and 3,2742° to rigth side between Nóbilo's occlusal plane and the Natural one; 5,2960° to left side and 5,4013° to right side between Camper's plane and Nóbilo's one and 1,9630° to left side and 2,0127° to right si de between Camper's plane and the Natural one, and there were no significant difference between lefi and right sides. This last one gave us the opportunity to compare values of the literature whieh are around 50' eompatible with the size of the samples. Thus, the values obtained in this researeh are eloser to parallelism. The lowest index of reliability found was 0,7721° in relaeion to the Natural plane and Nóbilo's one. This value determines a lower variability between the individuais of the sample when these planes are analysed. The presenee of 2% the reverse occlusal plane in the analysis between Camper's plane and Nóbilo's one , 4% in relation to Nóbilo's plane and Natural one, and 30% in relation to Camper's plane and the Natural one was verified by the Exact Test of Fisher. The Nóbilo's oeelusal plane can be accepted with seeurtty due your lower vartability between the individuais, a by lower percentage of the reverse occlusal plane, because your capable of being reproduced. / Mestrado / Fisiologia Oral / Mestre em Odontologia

Ziel dieser retrospektiven Studie war die Untersuchung verschiedener Wachstumsvorgänge im Ober- und Unterkiefer jugendlicher Patienten, speziell die der retromolaren Räume, am Fernröntgenseitenbild. Für diese Studie wurden insgesamt 305 Fernröntgenseitenbilder der Polikliniken für Kieferorthopädie der Universitätskliniken Leipzig und Dresden mittels der Software OnyxCeph³™ von Image Instruments ausgewertet. Mit dieser Studie konnte gezeigt werden, dass die retromolaren Räume im Alter von 9 – 16 Jahren durchschnittlich annähernd linear und bei beiden Geschlechtern in gleichem Maße zunehmen. Für den mandibulären retromolaren Raum wurde anhand der gewonnenen Durchschnittswerte die vereinfachte Formel Lebensalter + 12 in mm entwickelt. Damit ist eine Einschätzung des retromolaren Platzangebots anhand des Alters möglich. Fast alle vermessenen Strecken korrelieren signifikant mit dem chronologischen Alter, die höchste Korrelation besteht dabei für den retromolaren Raum des Unterkiefers. Neben bereits in anderen Studien zum Zwecke der Altersdiagnostik untersuchten Strecken, wie der Unterkieferlänge, kann zukünftig auch der retromolare Raum zur Altersschätzung anhand des Fernröntgenseitenbildes herangezogen werden. Verschiedene Autoren empfehlen zur Altersschätzung eine Kombination mehrerer Parameter. Mit drei in dieser Studie bestimmten Parametern konnte für beide Geschlechter eine Formel zur Altersschätzung aufgestellt werden. Der Standardschätzfehler beträgt jeweils 1,05 Jahre (Jungen) bzw. 1,28 Jahre (Mädchen).

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