The sagittal split ramus osteotomy is a common procedure used to correct jaw deformities. The lingula is an important anatomical landmark that is used as a reference to position the horizontal osteotomy cut on the medial aspect of the mandible. Knowledge of its position in relation to surrounding anatomical structures is essential in order to prevent complications related to the procedure. The aim of this study was to provide medical and dental practitioners with useful data regarding the position of the lingula in relation to surrounding anatomical landmarks. Such data may be of clinical relevance when performing surgery on the mandibular ramus and when providing anaesthesia for routine dental procedures. The study involved anthropometric measurements on adult dry mandibles obtained from the ‘Dart Collection’ at the School of Anatomical Sciences, University of the Witwatersrand, Johannesburg. A total number of 113 adult human dry mandibles were studied. From these specimens, 201 sides were examined. The most common shape of lingula noted within the study was that of the truncated type which was found in 38.8% of cases, followed by the triangular, nodular and assimilated types which comprised 30.8%, 21.4% and 8.9% respectively. The average distance of the tip of the lingula from the anterior border, posterior border and sigmoid notch the ramus of the mandible was approximately 20.15mm, 16.77mm and 16.3mm respectively. The average distance of the tip of the lingula from the mandibular second molar tooth was found to be 33.3mm. The lingula was above the level of the occlusal plane in 63.7% of cases, by an average distance of 6.5mm. The width and height of the mandibular foramen exhibited great variation. Anatomical differences in Caucasian and Black mandibles were noted, with the 4 rami of Caucasian mandibles generally being smaller in dimension compared to black mandibles. The anatomic data provided by this study may assist surgeons to locate and identify the lingula without difficulty, and avoid intraoperative complications. The data presented has a direct relevance to clinical practice and teaching.

Original published work submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy Johannesburg, South Africa, 2017. / During development and growth, the mandible adapts to accommodate increased biomechanical loading associated with the development and growth of the tongue and the dentition. Biomechanical loads play a vital role in the modelling and remodelling of bone, with site-specific effects on bone density. In the functional transition from the prenatal to the postnatal period, biomechanical loading appears to be intensified and may affect the morphology of the mandible. The aim of this study was to analyze the growth and development of the human mandible during the functionally complex perinatal period of growth in order to investigate biomechanical effects. As edentulism modifies the biomechanical landscape of mastication, the effects of tooth loss on the morphology of the adult mandible were also investigated. Seven hundred and seventeen mandibles were sourced from cadaveric and skeletonized remains forming part of the Paediatric Collection, Raymond A. Dart Collection of Human Skeletons and Johannesburg Forensic Paediatric Collection, University of the Witwatersrand. The morphometric growth relationships between the mandible and tongue were initially investigated. A strong correlation between changes in the dimensions of the mandible and tongue was observed between 20 gestational weeks and 2 years. It was hypothesized, that mandibular growth was directed by the growth of the tongue. This would result in areas of increased bone modelling and remodelling, directly associated with the attachment of the tongue to the mandible and would manifest in areas of lower density bone. Subsequently, variations in bone mineral density of the body of the mandible were assessed. The lingual surface had significantly higher bone density values when compared to the external surface across the period of 30 gestational weeks to 5 years. Variations in the bone density across the external surface of the mandible followed the patterns of postnatal dental development. Thus, the effects of edentulism on the morphology of the adult mandible were also considered. The edentulous mandible had a shorter alveolar height and mandibular body length as well as more obtuse gonial and mental angles, when compared to the dentate mandible. Thus, changes in the morphology of the mandible over time appear to be indicative of an altered mandibular morphology prompted by a changing biomechanical landscape. / MT2017

Thesis (M.S.)--University of Michigan, 1979.

Thesis (M.S.)--University of Michigan, 1982. / Typescript (photocopy). Includes bibliographical references (leaves 73-78). Also issued in print.

Thesis (M.S.)--University of Michigan, 1979.

Thesis (M.S.)--University of Michigan, 1982. / Typescript (photocopy). eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 73-78).

Thesis (Ph. D.)--University of Hawaii at Manoa, 2001. / Includes bibliographical references (leaves 240-272). Also available on microfiche.

Thesis (M.S.)--West Virginia University, 1999. / Title from document title page. Document formatted into pages; contains vi, 83 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 45-48).

Thesis (M.S.)--University of Michigan, 1963.

Thesis (M.S.)--University of Michigan, 1067.