|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Morphologic and Morphometric Analysis of Lingula in Localizing Mandibular Foramen with its Surgical Importance |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Phalguni Srimani, Biplab Goswami, Sibani Mazumdar 1. Assistant Professor, Department of Anatomy, Calcutta National Medical College, Kolkata, West Bengal, India. 2. Assistant Professor, Department of Anatomy, Calcutta National Medical College, Kolkata, West Bengal, India. 3. Professor and Head, Department of Anatomy, Calcutta National Medical College, Kolkata, West Bengal, India. |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Correspondence Address : Dr. Phalguni Srimani, Geetanjali Apartment, Flat No. 101, 37A, G. T. Road, P.O. Rishra, District Hooghly-712248, Rishra, West Bengal, India. E-mail: falgunisreemani@yahoo.co.in |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| ABSTRACT |  | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
: Morphometry of body and neural arch of lumbar vertebrae is very crucial in manufacturing screws, interspinous implants as well as preoperative planning of surgeries involving dorsolumbar spine. Aim: To determine various dimensions of typical and atypical lumbar vertebrae. Materials and Methods: A descriptive osteological study was carried out which included 66 intact adult dry human lumbar vertebrae (53 typical and 13 atypical) which were free of any deformity or pathological features. All the 53 typical vertebrae were randomly obtained. The following parameters were measured with slide callipers- superior transverse diameter and superior antero-posterior diameters of vertebral foramen; transverse diameter, antero-posterior diameter and anterior height of vertebral body; width, height of pedicles; interpedicular distance; maximum thickness of lamina; length of transverse process; maximum length, maximum height and maximum central thickness of spinous process. The data was tabulated and analysed using Microsoft Excel software. Mean and standard deviation was calculated for each parameter. Unpaired t-test was applied and p-value was derived for parameters like width and height of pedicles, thickness of lamina and length of transverse process. The p-value<0.05 were considered as significant. Results: The vertebral foramen (superior transverse diameter- 20.41±2.54 mm, superior antero-posterior diameter- 13.3±2.04 mm); vertebral body (transverse diameter- 44.43±5.91 mm, antero-posterior diameter- 30.17±3.19 mm, anterior height- 24.01±1.84 mm); pedicle (width- 10.85±3.94 mm on left side and 11.04±4.01 mm on right side, height- 13.84±4.01 mm on left side and 13.8±1.93 mm on right side, interpedicular distance- 29.17±5.06 mm); lamina (thickness- 6.6±1.36 mm on left side and 6.85±1.34 mm on right side); transverse process (length- 20.94±4.01 mm on left side and 21.51±4.5 mm on right side); spinous process (maximum length- 26.01±3.73 mm, maximum height- 19.92±4.03 mm, maximum central thickness- 6.42±1.41 mm). The mean transverse diameter and antero-posterior diameter of vertebral foramen of atypical lumbar vertebrae were higher than those of the typical lumbar vertebrae and these differences were significant (p-value of 0.0001 for transverse diameter and p-value of 0.005 for antero-posterior diameter). Conclusion: Most of the parameters of atypical lumbar vertebrae were found to be more compared to those of typical lumbar vertebrae. This inference should be kept in mind during fixation of lumbar inter-spinous implants, designing of pedicular screws and spinal grafting. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Keywords : Inferior alveolar nerve, Mandible, Maxillo-facial surgery | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| INTRODUCTION |
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mandibular foramen is located on the medial surface of mandibular ramus a little above the centre which leads to mandibular canal running initially obliquely downwards and forwards within the ramus and then horizontally forwards within the body of mandible under the roots of molar teeth. Fine branches from inferior alveolar vessels and nerves also supply mandibular teeth, gums and lower lips. The mandibular foramen is overlapped anteromedially by a thin sharp triangular spine like bony process, called lingula which can be palpated through oral mucosa. In edentulous subjects, lingula is situated in higher position as compared to subjects having teeth (1). Lingula was first described by Johannes – Baptist as ‘Spix ossicle or spine’ in 1815 (2). Nicholson reported variation of height and shape of lingula upon examination of adult mandibles of East Indian ethnic origin, but no description was mentioned (3). Tuli et al., studied adult mandibles of Indian origin and first described different morphological shapes of lingula as triangular, truncated, nodular and assimilated types (4). Previous study was also conducted to identify the position of lingula using structures present on external surface of mandibular ramus known as ‘anti-lingula’, though it might not be always present (5). The variant shape of lingula can also be used as anthropological marker to assess different population along with other non-metric variants of skull (6). Considering the close relationship of lingula with neurovascular structures entering through mandibular foramen, lingula is often used as an important bony landmark for different maxillofacial surgical interventions and inferior alveolar nerve block anaesthesia which are commonly done in dentistry. Inadequate knowledge about structural variations of lingula leading to inaccurate localization of mandibular foramen may result in intra-operative complications like haemorrhage, fractures and even damage to inferior alveolar nerve (7),(8). Difficulty in localizing mandibular foramen resulting from variations of lingula has also been implicated as causative factor for unsuccessful inferior alveolar nerve block anaesthesia. Failure of inferior alveolar nerve block anaesthesia has been described as high as 45% of which nearly 10-15% failure rate are attributed to structural variations of lingula (3),(9). Previous literature indicated studies which have been performed to widen the scope for better understanding of morphology and morphometrics of lingula based on anthropometric location of surrounding mandibular landmarks (4),(10),(11),(12),(14),(14),(15),(16),(17). Taking into consideration of increased interest in recent past, studies on this topic on Indian population are meager especially in West Bengal and here lies the importance of the present study, which was attempted to compile data on lingula of mandibles collected from different Kolkata based medical colleges in terms of variations in morphology and morphometry on both right and left sides. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| TABLES AND FIGURES |
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Original article / research
|
