Objectives: The aim of the study was to evaluate the accuracy of linear measurements obtained from reconstructed spiral CT images of human dry skulls in three planes by comparing them with direct skull measurements, and then to compare these with measurements made on photostimulable phosphor cephalograms. Methods: Using a Siemens Somatom Sensation spiral CT scanner (Munich, Germany), CT images of six human dry skulls were imported into imaging software (Mimics 11.02 Materialise, Leuven, Belgium) and the measurements made were compared to the direct measurements made using a digital calliper (500-171, CD-6C, Mitutoyo, Kawasaki, Japan). The measurements were also compared to those made on frontal and lateral cephalograms taken using a digital cephalostat (Planmeca Oy, Helsinki, Finland). The mean of the 15 linear measurements obtained were compared using the paired Student's t-test. Results: CT measurements did not show a significant difference from the direct skull measurements (P , 0.05) in all three planes except for two midsagittal measurements in the anteroposterior plane. Cephalometric measurements were comparable to direct skull measurements for midsagittal measurements in the anteroposterior plane, but showed a significant difference when bilateral measurements were considered. Cephalometric measurements also showed a significant difference in the transverse plane from direct measurements and CT measurements; however, they did not display a significant difference between direct skull measurements and CT measurements for most parameters in the vertical plane. Conclusion: Linear measurements on the spiral CT were comparable to anatomical measurements and were more reliable than cephalometric measurements. Cephalometric measurements were acceptable for midsagittal measurements in the anteroposterior plane, but showed a significant variation from anatomical and CT measurements in most other parameters.

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IntrOductIOnSurgical extraction of impacted mandibular third molar is one of the most commonly performed day care procedure in Oral and Maxillofacial Surgery either for therapeutic or prophylactic purpose. It is often associated with complications like pain, swelling, trismus, dry socket, bleeding and infection, which are typically temporary in nature. However, the most concerning complication is temporary or permanent damage to the Inferior Alveolar Nerve (IAN) resulting in paresthesia, hypoesthesia or dysesthesia of the lower lip, teeth, gingiva and skin over the chin, which significantly affects the quality of life of the patient [1].Ahmed C et al., reports that the common risk factors for the IAN damage includes advanced age and difficult impaction but the most important one is the proximity of the root to the IAN canal [2]. The incidence of IAN injury following mandibular third molar extraction is 0.41% to 8.1% for temporary altered sensation and 0.014% to 3.6% for permanent nerve damage [3]. But the incidence increases up to 20% to 36% in high risk cases as defined by radiographic signs described by various authors [4,5] which includes alteration in the root structure (darkening, narrowing, root deflection, bifid apex or overlapping over the nerve canal) or alteration in the inferior alveolar canal features (obliteration of radio opaque line, deflection or narrowing of the inferior alveolar canal). In these cases the nerve injury may occur either due to the instrumentation or due to crushing and tearing of the nerve by the root during tooth elevation [4].Various approaches have been proposed to decrease damage to the IAN in high risk cases, which comprises coronectomy and leaving the roots behind, staged surgical removal of the third molar [6], modified coronectomy and grafting [7], orthodontic aided extrusion [8] and pericoronal ostectomy [9]. Staged tooth removal was proposed to minimize the late post-operative risk of infection of retained roots, but requires two surgical interventions and the amount of root migration is unpredictable. Modified coronectomy with grafting was advocated for restoring the periodontal health of the second molar. Orthodontic aided extrusion of the third molar is technique sensitive, time consuming, expensive and unpredictable procedure. Applied coronectomy to prevent IAN damage was first proposed by Ecuyer and Debien [10] in 1984. In spite of numerous studies supporting the effectiveness of coronectomy, the procedure remains controversial due to the possibilities of infection and other odontogenic pathology arising from the roots left behind [11]. The aim of present study was to evaluate the outcome after coronectomy of mandibular third molars in terms of complications encountered during or after the procedure, temporary or permanent IAN injury, infection rate and other associated morbidity.

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Aim:The aim was to determine the morbidity or mortality associated with the blind awake intubation technique in temporomandibular ankylosis patients.Settings and Design:A total of 48 cases with radiographically and clinically confirmed cases of temporomandibular joint (TMJ) ankylosis were included in the study for evaluation of anesthetic management and its complications.Materials and Methods:Airway assessment was done with standard proforma including Look externally, evaluate 3-3-2 rule, Mallampati classification, Obstruction, Neck mobility (LEMON) score assessment in all TMJ ankylosis patients. The intubation was carried out with the standard departmental anesthetic protocol in all the patients. The preoperative difficulty assessment and postoperative outcome were recorded.Results:Blind awake intubation was done in 92% of cases, 6% of cases were intubated by fiberoptic awake intubation, and 2% patient required surgical airway. Ninety-eight percent of the patients were cooperative during the awake intubation. The frequent complications encountered during the blind awake intubation were epistaxis and sore throat.Conclusion:In an anesthetic setup, where fiberoptic intubation is not available, blind awake intubation could be considered in the anesthetic management algorithm.