Prevalence Of Anterior Loop Research Articles

ASSESSMENT OF LOCATION AND COURSE OF INFERIOR ALVEOLAR CANAL USING CONE BEAM COMPUTED TOMOGRAPHY

Background and Rationale:Forensic radiology is an evolving integral branch of forensic medicine. The most challenging tasks for forensic dentists and anthropologists has been identification and determination of sex of unknown human skeletal remains. Morphological and morphometric analysis of course and relationship with adjacent structures of mandibular canal can be useful in determining gender. CBCT being very useful in forensic contexts offering several advantages for postmortem forensic imaging including good resolution for skeletal imaging, relatively low cost, portability, and simplicity. Aim and objectives:To determine the sexual dimorphism of mandibular canal using cone beam computed tomography (CBCT) images. Materials and Methods:Course of mandibular canal classified into types based on considerable distance between the mandibular canal and the root apexes of premolars and molars, A) Catenary, B) Progressive descending, C) Straight. Location of mandibular canal was evaluated in 4 different points. Comparison of length and width of mandibular canal, prevalence of anterior loop, bifid mandibular canal, accessory mental and mandibular canal among genders. Comparison of continuous variables such as distance, length and width of canal with gender and side was done using unpaired t-test. Comparison of categorical variables with gender and side was performed using Chi-square test. The level of significant was 5%. Results:The prevalence of type of canal was highest in straight canals 53.9% followed by progressive descending and catenary canals 23.7% and 22.4% respectively. Measuring the length of canal showed statically significant result as mean length of IAC was 68.36 ± 5.24, 64.10 ± 3.18 in males and females respectively. Width and distance to adjacent structures had no significant result but dimensions were slightly lesser in females. Prevalence of anterior loop was found to be 57.9%.The most frequently observed type of bifid canal was retromolar42.9% followed by forward 28.6%, dental 19%and buccolingual 9.5%. There was no significant difference of assessing prevalence of anterior loop, accessory mental and mandibular foramen in relation to gender and side. Conclusion:Sex determination becomes one of the first priorities in the process of identification by a forensic investigator in the case of mishaps, chemical and nuclear bomb explosions, natural disasters, crime investigations, and ethnic studies.Advanced cross-sectional imaging modalities especially CBCT is a suitable tool for observing anatomic characteristics of mandibular canal in forensic odontology. In the current study we found significant result on type of course and length of canal for gender determination.

Evaluation of Morphologic and Morphometric Characteristics of the Mental Foramen and Anterior Loop in a Turkish Subpopulation Using Cone Beam Computed Tomography

Objective: Before a surgical intervention in the mandibular interforaminal area, it is important to have a full understanding of the anatomy of the mandibular anterior segment. The evaluation of anatomical structures, variations and pathologies is performed with radiological imaging methods. Today, cone beam computed tomography (CBCT) is an imaging method which offers all the features necessary for this. In addition to its importance in surgical applications, it is also valuable in terms of anatomical studies thanks to the reliability of its measurements and the fact that it allows for a three-dimensional evaluation. The mental foramen and anterior loop are some of the most significant anatomical structures in the lower jaw. The aim of this study was to determine the characteristics of mental foramen according to age and gender in a Turkish population and to evaluate anterior loop length and the frequency of anterior loop. Methods: In this retrospective study, CBCT images from 148 patients (89 females and 59 males) were examined. Images of the mental foramen and interforaminal area of patients who were over 18 years of age were included in the study, while images with mandibular pathology and without occlusal closure to at least premolar teeth were excluded. Linear measurements of the mental foramen were repeated three weeks later by the same observer. Descriptive statistics (mean, standard deviation) and the Kolmogorov-Smirnov, Kruskal-Wallis, Mann-Whitney U, ANOVA tests and the t-test were used to evaluate the data. Results: The morphological and morphometric features of the mental foramen, which is a characteristic structure in mandibular bone, were determined. No statistically significant difference was found between the age groups in the morphometric characteristics of the mental foramen, but a statistically significant difference was found according to gender. The most frequently detected oval shape and P3, and P4 positions were similar to the other studies conducted in Turkish populations. The prevalence of anterior loop was 58%. Conclusion: Detailed preliminary analysis focusing on anesthesia and surgical interventions is important in order to avoid possible complications

Un estudio de tomografía computarizada de haz cónico para evaluar el asa anterior y otras variaciones anatómicas en el área del foramen mentoniano en una población iraní

Purpose: This study aimed to determine the prevalence and length of the anterior loop (AL) of the inferior alveolar nerve, and evaluate the emergence direction of the mental nerve and the location of mental foramen in a group of Iranian patients. Material and Methods: This study was carried out on CBCT scans of 150 patients (57 males and 93 females; mean age 40.8 ±14.33 years). The presence and extent of the AL was determined in reconstructed images. The emergence path of the mental nerve was classified into three groups: anteriorly directed emergence, right-angled pattern of emergence, and posteriorly directed emergence. The location of mental foramen relative to adjacent premolars was determined. Results: AL was identified in 14.7% of the cases with a mean length of 1.39± 0.91 mm (range 0.25 to 3.50 mm). No significant differences were observed in the prevalence and extent of the AL between genders (p>0.05). The right-angled pattern of emergence was more dominant (43.7%). The most prevalent location of mental foramen was between the first and second premolars (68.3%). There was no significant association between the presence of AL with the path of emergence of the mental nerve (p=0.627) or the location of the mental foramen (p=0.100). Conclusion: The prevalence of anterior loop was relatively low in the present sample (14.7%) with a length range of 0.25 to 3.5 mm. Due to the importance of this anatomic variation in implant surgery, it is suggested to carefully assess CBCT images before the surgical procedure to avoid neurosensory complications.

Prevalence of Anterior Loop and other Patterns of Mental Nerve in a Sample Population of an Indian City: A Retrospective Study.

Introduction:The final portion of the inferior alveolar nerve (IAN), the mental nerve (MN), is a general somatic afferent nerve that provides sensation to the lip, chin, and gingival tissue. Three patterns of MN have been observed – straight, perpendicular or vertical, and anterior loop (AL) of MN. The interforaminal region of the mandible possesses a MN with a path that creates an AL before entering the mental foramina. The aim of the study is to evaluate the presence of AL of MN using cone-beam computed tomography (CBCT) and to measure the length of the AL of MN, if present, also to evaluate the prevalence of other anatomical patterns of MN – straight and vertical patterns.Materials and Methods:Mandible CBCT of 400 patients with the age of 20 years onward was included in the study. The images obtained were assessed for the different patterns of MN – straight, vertical, and ALs. The statistical analysis was done using the Chi-square test, paired t-test, and sample t-test.Results:Out of 400 CBCT scans comprising 800 hemimandibles, straight pattern was observed in 67.1%, vertical pattern in 26%, and Anterior Loop in 6.9%. The prevalence of AL pattern was 6.9%. AL length was found to be in a range of 2.4–6.6 mm.Discussion:Surgical trauma or injury to the AL of MN is possible during implant surgery in the interforaminal area of the mandible if AL is not assessed preoperatively.

Evaluation of morphometric variations in mental foramen and prevalence of anterior loop in South Indian population – A CBCT study

Introduction: The mental foramen (MF) opens on the lateral aspect of the mandible near premolar region on both sides of the mandible. The portion of inferior alveolar nerve present anterior to the MF, prior to exiting the canal, is referred to as the anterior loop (AL) of the inferior alveolar nerve. These anatomical variations cannot be evaluated by conventional imaging techniques. Cone beam computed tomography (CBCT) provides three-dimensional reliable images of maxilla–mandibular region. Hence, it plays an important role to detect and evaluate these anatomical variations and to prevent intra- and postoperative complications. Materials and Methods: This retrospective observational study includes 500 CBCT images of the mandible. The average size, location, shape of MF, and presence of AL were assessed in sagittal, tangential, and axial sections. Results: Out of 250 CBCT scans analyzed, 132 scans (52.8%) were of males and 118 scans (47.2%) belonged to females. The mean size of MF as measured in the sagittal sections was found to be 3.36 mm in height and 2.54 mm in length. The most common position for the MF related to the mandibular teeth in this study was between first and second premolars in 310 CBCT images (62%). A majority of the MF were oval in shape (n = 346, 69.2%) followed by round shape (n = 154, 30.8%). The presence of AL of inferior alveolar nerve was found in only 20% (n = 100) of cases in this study. Conclusion: Considering these variations in MF and AL, the use of CBCT seems necessary for better evaluation and treatment planning.

Efficacy and evaluation of cone beam computed tomography in determining the prevalence and length of anterior loop of inferior alveolar nerve in North Indian population

Introduction: The section of the inferior alveolar nerve (IAN) in front of the mental foramen and just before its ramification to the incisive nerve is known as anterior loop (AL) of IAN. Surgeries in the area of the anterior mandible may violate the AL resulting in neurosensory disturbances. Cone beam computed tomography (CBCT) is a new imaging modality that provides a multidimensional view of the facial skeleton. Aim: To evaluate the efficacy of CBCT in measuring the anterior looping of IAN. Objectives: To determine the prevalence of AL of IAN using CBCT, and to determine AL length using CBCT. Materials and Methods: Out of the total 1075 reported patients, 193 study participants fulfilling the inclusion criteria constituted the sample size were assessed for estimating the prevalence and determining the length of AL of IAN. They were scanned with a suitable digital imaging system for a variety of clinical indications using appropriate Dental Imaging Software. Results: The prevalence of anterior looping was found to be 37.3% and was highest (43.5%) in the age group of 36–56 years and was found to be statistically significant. The mean length of anterior looping was found to be 3.661 mm (SD ± 1.9933) with a maximum loop length of 8.8 mm. Conclusion: CBCT provides an accurate means to determine the anterior looping of IAN, measures its length, and thereby, helps in preoperative surgical planning.

Determination of the position of mental foramen and frequency of anterior loop in Saudi population. A retrospective CBCT study.

ObjectivesTo determine the position of mental foramen (MF) and frequency of anterior loop (AL) using dental cone beam computed tomography (CBCT).Materials and methodsThe study involved the evaluation of 302 CBCT scans (196 males, 106 females). The position of MF was determined with respect to adjacent teeth, nearest root apex of adjacent teeth and mandibular borders. MF position was also assessed based on gender and age. In addition, prevalence of anterior loop was evaluated by categorizing the inferior alveolar canal (IAC) patterns into linear, perpendicular and anterior looping.ResultsThe study revealed that the most common position of MF was below the apex of 2nd premolar accounting for a total of 52.8% of scans whereas, only 29.6% observed MF between 1st and 2nd premolar (p > 0.05). 38.7% of MF were located at a distance of 1–3 mm from the nearest root apex (2nd premolar), followed by a distance of less than 1 mm in 17.05 of cases. 63.2% of foramen on left side of the mandible were observed below the apex of 2nd premolar in females (p = 0.023). Statistically significant findings were observed with regards to position of MF in different age groups (p < 0.05). The most common IAC pattern observed was linear in nature which accounted for 46.2% of cases followed by perpendicular pattern (38.6%). AL was found only in 15.2% of cases.ConclusionsOur sample population most commonly exhibited MF below the apex of 2nd premolar with linear IAC pattern. AL was regarded as the least common pattern in Saudi population.