Original Research Article Journal of Oral Medicine, Oral Surgery, Oral Pathology and Oral Radiology, 2016; 2(4):203-209 203 Evaluation of impacted 3 rd molars in Indian ethinicity on panoramic radiograph-a cross sectional study Akhilanand Chaurasia 1,* , Sachidanand Giri 2 , Ranjit Kumar Patil 3 1 Assistant Professor, 2 Resident, 3 Professor & Head, Dept. of Oral Medicine & Radiology, Faculty of Dental Sciences, King George’s Medical University, Lucknow *Corresponding Author: Email: chaurasiaakhilanand49@gmail.com Abstract Objective: The aim of present study is to know the association between types of impaction and jaws in males and females. This study also evaluates the prevalence of impaction according to age in maxilla and mandible. Material and Methods: The orthopantomograms of 198 subjects were taken from Planmecca PM 2002 cc Proline Panoramic X-ray unit at Kvp (60-80), 10 mA at exposure time 18 second. The orthopantogram evaluated for type of impaction as per Winter’s classification and related findings were recorded. Results: The recorded data is analyzed by using Statistical Package for Social Sciences (SPSS) version 21.0. The maxillary right and left side is more predilected for vertical impaction in male and female population and it was statistically significant (p<.05). The mesioangular impaction is most common impaction in mandible and it was statistically non-significant (p>.05) in either gender. In all age groups, vertical impaction is most common type of impaction in maxilla however mesioangular impaction is most common type in mandible. Conclusion: The vertical impaction is most common type of impaction in maxilla and mesioangular impaction is most common type in mandible in all age groups and gender. Keywords: Panoramic Radiograph, Mandible, Impacted 3 rd Molar. Introduction Tooth impaction is a common phenomenon. (1,2) The impacted teeth are those teeth which are unable to erupt or have delayed eruption. An impacted tooth is classified as erupted, partially erupted or unerupted and they do not have a normal arch relationship with the other teeth and tissues. (3) The common causes for third molar impaction is crowding, ectopic position of the tooth germ, supernumerary teeth and soft tissue or bony lesions. (3,4) Insufficient space is the commonest cause for the third molar impaction. An impacted tooth can result in caries, pericoronitis, pulp disease, periapical and periodontal disease, root resorption of the adjacent tooth and maxillofacialcysts and tumors. (5,6) Systemic factors such as genetic disorders, endocrine deficiencies and irradiation of the jaws are also causes for impaction. (7,8) Winter’s classification system is commonly considered for assessing the angle of impacted teeth which evaluates the angle formed between the intersected longitudinal axes of the second and third molars. (9) For explaining the prevalence and incidence of dental impaction, many theories have been put forward from time to time. Mendelian theory, phylogenic theory and orthodontic theory are among the most dominant and widely accepted theories among all. The concept of discrepancy between the size of the tooth and space available in the jaws due to size variation occurring in the jaws is the most frequently reason in all the major theories. (10) Dietary habit has also influence on pre-velance of impacted molars which varies from one region to the other. Considerable variations has been reported in the prevalence and distribution of impacted teeth in different regions of the jaw. (11) The mandibular and maxillary third molar, maxillary canine, maxillary lateral incisor and mandibular premolars are the commonly impacted permanent teeth. Mandibular and maxillary third molars are the most frequently impacted teeth with slight predilection to the mandibular molars. (3,4) The third molars have a relatively high chance of becoming impacted. (12) Many factors have been reported to be responsible for the high rate of impaction of mandibular third molars. These include insuficient space in the dental arch (13) unfavourable angulations and aberrant path of eruption, density of overlying soft and hard tissues and the late eruption sequence. (13) Mesiodistal diameter of the third molar may also play a role in the tendency for impactions. Svendsen and Maertens have reviewed in detail the etiology of third molar impactions. Two of the main causes for impaction was insufficient anterior- posterior dimension and late third molar mineralization and early physical maturation. (14) The impactions occurs in different angulations and positions and may occur in both jaws (maxilla and mandible). Identification of impactions can be done clinically and radiographically by orthopantomographs, lateral obliques and periapical radiographs. The radiograph of choice to assess third molar impactions is the orthopantomograph. (15) The