European Journal of Molecular & Clinical Medicine

The effectiveness of various imaging modalities in locating the mandibular canal was evaluated, including computed tomography (CT), panoramic radiography, and tomography. Cone-beam computed tomography (CBCT), a recently established imaging technique, appears to be a promising one that, when compared to conventional CT, also significantly lowers patient exposure. There are no studies in the literature comparing its performance with other conventional imaging modalities in such delicate tasks as mandibular-canal identification. This study compared digital panoramic photos and CBCT-reformatted panoramic images to identify the mandibular canal as part of preimplant evaluation.

Background: The impaction rate is much higher for third molars as compared to other teeth. While impacted third molars may remain asymptomatic for an indefinite period, it can cause various delinquents, such as pericoronitis, swelling with pain, distal caries, bone loss, root resorption of adjacent teeth, odontogenic cysts, and tumors. That’s why the most frequent surgical procedure in dentistry is third molar tooth extraction.
Objective: The aim is to propose a new classification for impacted mandibular third molars on CBCT images which cover all aspects of the anatomical situation
Methodology: A total of 143 images of molar teeth was collected and classified according to a relationship with the IAN canal and molar tooth. For statistical calculation, SPSS software was used.
Results: Classes 0-7 were planned and in which classes 1-6 were sectioned into two subtypes (subtypes A-B). The distribution of the classes presented an occurrence of buccal or apical course of the mandibular canal tailed by lingual position and inter-radicular one. Results emphasized that a close relationship of molar roots with the lingual side of IAN was more in female versus male other than it no anatomic differences occur in terms of IAN relationships between males and females. Younger patients displayed an increased rate of direct contact with a reduced calibre of the canal and/or without corticalization. This increases the chances of IAN damage, especially in the young woman (age range 25-30 years) with a lingual course of the mandibular canal.
Conclusion: The use of this classification is appreciated to get an equal definition of the impacted tooth on CBCT images worldwide.

Background and objectives: The upper and lower airway has always been an area of interest because the oropharyngeal and nasopharyngeal structures play important roles in the growth and development of the craniofacial complex. Significant relationships between the pharyngeal structures and both dento-facial and craniofacial structures have been reported. The aim of the study were to evaluate Oropharyngeal and nasal passage volumes of patients with normal nasorespiratory functions having different dentofacial skeletal patterns using CBCT and the correlations between different variables and the airway Material and Methods: The study consisted of 45 patients (23 males, 22 females), divided into 3 equal groups as Class I , Class II and Class III based on evaluation of facial profile and molar relation. After obtaining CBCT, the Oropharyngeal airway volume (OPV), Nasopharyngeal airway volume (NPV), vertical height of oropharynx (HOP), Constricted minimum axial area (CMinAx), and Constricted posterior airway space (CPAS) were measured. Differences between groups were determined by using the Tukey Post Hoc test. Correlations between the variables were tested with the Pearson's correlation coefficient. Results: The mean OPV of the Class II subjects (6876.40 mm3) was significantly lower when compared with that of the Class I (8294.73 mm3 ) and Class III subjects (10941.43 mm3 ). The only statistically significant difference for NPV was observed between the Class I (9889.57 mm3) and Class II groups (7916.48 mm3 ). The CMinAx had a high potential in explaining the OPV.Conclusion: The results from this study indicate that mandibular growth deficiency patients had less airway volume, minimum axial area and constricted posterior airway space than the patients with good growth anteroposterior relationship between maxilla and mandible. The results of this research can be used as a guideline for subsequent works related to the airway study and presurgical assessment for orthognathic surgeries

Purpose of the study : This study aimed to determine the height at which both the lateral
and medial cortical bone layers of mandibular ramus merge, using a reference point on the
anterior margin of the mandibular ramus and comparing with lingula as another
reference point, using cone beam computed tomography, thus establishing an effective
method of determining the level of the horizontal cut of sagittal split osteotomy.
Material and Methods: The mandibular ramus of 15 patients were analysed on a three
dimensional (3D) model constructed using Cone Beam Computed Tomography. Starting at
reference point (A), a line was marked from the anterior border of the ramus of mandible
till the posterior border on lateral surface. On three vertical section of the ramus (1/3rd
and 2/3rd and lingula), the level at which both lingual and buccal cortices meet were
determined- A1 and A2 and L respectively.
The results of the study showed that mean height of fusion of medial and lateral cortices at
1/3rd and 2/3rd and lingula were 8.96mm, 4.62mm and 11.00mm respectively.
Conclusion:The point A is a safe and easy to locate anatomic reference point to establish
the level of horizontal cut in sagittal split ramus osteotomy (SSRO).

Introduction- As we know that form follows function, the altered nasorespiratory function can lead to altered craniofacial growth. This predisposes to mouth breathing, OSA, adenoid hypertrophy which are a matter of grave importance today. Many orthodontic procedures may lead to reduced lower airway space if underlying conditions are not paid enough attention to. This forces the orthodontist to be more precise in their diagnosis and treatment planning especially planning formulated in accordance with obstructive sleep apnoea. The early diagnosis and early intervention of these conditions can prevent more severe associated problems. There are multiple evaluations of airway status undertaken by anesthetist and ENT surgeon some of which may benefit orthodontist for timely intervention. These methods include roentgenograms, CT,CT bronchography, virtual bronchoscopy, MRI, 3D printing, Ultrasonography, Nasal endoscopy, rhinomanometry. CBCT and lateral cephalogram are the most commonly used diagnostic tool for airway analysis. The reliability of lateral cephalogram in the analysis of airway has been questioned several times in the past few years which puts up a need for evaluation of the technique and its reliability.
Objective- The aim of this article is to review all those literatures that relate to upper airway analysis using Lateral cephalogram to those of CBCT scans and to evaluate the reliability of lateral cephalogram. 
Conclusion- Lateral cephalogram can be used as an initial diagnostic aid for the analysis of airways. Although the three-dimensional airway is analysed using two-dimensional technique it is nonetheless an appropriate diagnostic tool for airway analysis.

Background: The present study compared hounsfield unit of CT with grey scale value of CBCT for hypo and hyperdense structure. Materials & Methods:15 human dry skulls were subjected to MSCT and CBCT and hyperdense areas of enamel, cortical, and cancellous bones and hypodense areas of mental foramen, inferior alveolar canal and extraction socket within the mandible were assessed. Results: For extraction socket CT had -860.5 HU and CBCT had -740.5 grey scale, for mandibular canal CT had -560.2 HU and CBCT had -726.4 grey scale, mental foramen had CT of -432.6 HU and CBCT had -458.6 grey scale, cancellous bone had CT had 346.2 HU and CBCT had 416.2 grey scale and cortical bone had CT 1880.4 HU and CBCT had 1652.8 grey scale. The difference was significant (P< 0.05).
Conclusion: The gray value for hypodense structures in large volume CBCT scan was more reliable and analogous to HU value in MSCT.

Impaction denotes a tooth failing to attain its normal position to reach the occlusal table with third molars impaction being common in the mandible. The conventional radiographic views such as peri-apical, panoramic radiograph are two dimensional representations of three dimensional structure. Absence of information on relation of vital anatomical structures to impacted teeth, bone quality is a drawback for the operating surgeon which could lead to pre or post operative complications. CBCT imaging fills the lacunae of two dimensional imaging and holds a key role in impaction assessment.A retrospective analysis of 45 patients who underwent CBCT imaging prior to extraction of impacted third molars were included in the study and the data was analysed using SPSS.Among the 45 patients, 20 were males (44.4%) and 25 were females (55.5%) and the age group commonly affected with impaction was between 25-30 years (35.5%).The frequency of impacted third molars was more in mandible (80.0%) compared to maxilla (20%).There was significant correlation between nerve involvement and angulation of impacted third molars.CBCT imaging modality provides a three dimensional view to help in better treatment planning, anticipating possible complications post surgery. CBCT must be recommended as the only imaging modality in impaction assessment.