the aim of this study was to correlate the best posterior reference point of ala - tragus line for orientation of the occlusal plane in dentate individuals .
in this cross - sectional study 50 dental students ( 35 females , 15 males ) [ graph 1 ] with complete natural dentition and angles class i occlusion was selected between the age groups of 2025 years . with the following exclusion criteria : 
 no previous orthodontic or prosthodontic treatmenthistory of any esthetic surgeryfacial asymmetry and craniofacial anomalyoverjet and overbite over 2 mm . 
  no previous orthodontic or prosthodontic treatment history of any esthetic surgery facial asymmetry and craniofacial anomaly overjet and overbite over 2 mm .
following this , the subjects were asked to hold a fox plane , covered with dental wax , between their teeth [ figure 1 ] . left profile photographs were taken with a digital camera , with the subjects standing in natural head position .
an adjustable tripod was used for adjusting the camera with the height of the fox plane in the subjects , then the photographs were traced [ figure 2 ] . after tracing photographs , angle between fox plane and superior border of ala - tragus , fox plane and inferior border of ala - tragus and fox plane and middle borders of ala - tragus line was measured and statistical analysis was performed using spss and cad software , version 13 .
after statistical analysis , the results were tabulated and following results were drawn [ graph 2 ] : the angles between the occlusal plane and ala - tragus superior , ala - tragus middle , ala - tragus inferior , are significantly different from zero .
it means no parallelism exists between the occlusal plane and the ala - tragus line .
there is also no parallelism between the fox plane and the ala - tragus with three posterior point locations in males and females ; however , the results showed that in both sexes the inferior border of the ala - tragus line had the lowest mean value and stronger tendency to be parallel to the fox plane .
there is a controversy for the orientation of the occlusal plane during complete denture fabrication .
some of the existing concepts regarding orientation of the occlusal plane in the edentulous patients are of the opinion that the occlusal plane has relation with camper 's line .
it would seem desirable to locate it accurately and propagate its use while establishing the occlusal plane .
spratley described it as running from the center of the ala to the center ( middle ) of the tragus .
boucher defines it as  the line is running from the inferior border of the ala of the nose to the superior border of the tragus of the ear .
 van niekerk et al . used the inferior border of tragus as the posterior end of the ala - tragus line because it could provide sufficient space for the arrangement of maxillary posterior teeth .
karkazis and polysois showed in a cephalometric study that natural and artificial occlusal planes are not parallel to the ala - tragus line .
dentulous individuals were evaluated to establish the definite correlation between camper 's plane and occlusal plane so that a similar relation could be established in edentulous individuals .
the average angles for natural and artificial teeth were 2.84 ( 3.45 ) and 3.25 ( 4.69 ) , respectively .
they used the center of the tragus as the posterior point for the ala - tragus line .
reported a mean of 3.94 between the occlusal plane and the camper plane , which is consistent with the results of the present study .
according to the results of the present study , the inferior border of the tragus is suggested as the posterior reference for the ala - tragus line .
positioning of the occlusal plane depends on mature clinical judgment and must ultimately satisfy esthetics , function , and denture stability .
 many methods have been used to establish the occlusal plane in complete denture prosthodontics . 
 however , no single method seems to be fully accepted . 
 anteriorly , esthetic considerations help define the occlusal plane , and posteriorly the tongue , retromolar pad , and stenson 's duct are considered . 
 some dentists bisect the space between the residual ridges . 
 the technique of using the ala - tragus line ( camper 's line ) to establish the occlusal plane is well documented . 
 however , definitions of the ala - tragus line cause confusion , because the exact points of reference do not agree . for example 
 , the glossary of prosthodontic terms states that the ala - tragus line runs from the inferior border of the ala of the nose to the superior border of the tragus of the ear while spratley describes it as running from the center of the ala to the center of the tragus . 
 this article concerns us the exact relationship between the occlusal plane and ala - tragus line in dentate individuals . 
Objective
Materials and Methods
Results
Discussion
Conclusion