Waheed Murad Dahri1 , Aamir Mehmood Butt2 , Bilal Ahmed3
How to CITE:
DahriWM, ButtAM,Ahmed B. Relationship of intercondylar distancewith intercanine distance in dental students. J PakDent Assoc.2012; 21(03):141-144
To see the relationship between intercondylar distance and themaxillary &mandibular intercanine distances in dental students.
One hundred fully dentateBDS studentswith age ranging from21 to 25 years, free fromfacial and dental deformities were examined. Upper and lower arch impressionswere taken using stock trays. Dental cast were made using type IV dental stone. Vernier Caliper was used to measure the linear distances on the cast. Intercondylar distancewasmeasured using arbitrary face bow (Hanau-H2) at rest position. Forkwas attached to the teeth with silicone impression material. Hing axis marks were made 13 mm anterior to the upper border on the tragus canthus lines on both sides of the face .The mark was confirmed by placing the middle fingers of both hands over the marks & students were advised to open & close the jaw by 20mm, the tactile sensation of rotating condyle confirmed the hinge axis location.Every distancewasmeasured three times to ensure the accuracy andmean taken.
The highest correlation was found between Maxillary Intercondylar Distance and Maxillary Intercanine Distance (r = 0·72, P=<0·0001) andMandibular Intercanine Distance (r = 0.309, p = 0.002). The mean intercondylar and maxillary intercanine distance was 1:4.41, while ratio between the mean intercondylar and mandibular intercanine distancewas 1: 6.42.
The observed relationship between the intercondylar and inter-canine distances could prove a useful guide for selection of teeth in edentulous patients.
Esthetics, Complete denture, Edentulous, Tooth arrangement, Intercondylar distance, Intercanine distance
Prosthodontists aims to rehabilitate the patient’s oral function, esthetics health, comfort and confidence. Esthetics is one of the major considerations for patients seeking prosthodontic treatment. It may be achieved by the replacement of the lost or congenitally missing natural teeth and associated oral structures. The best position of the artificial teeth is the one occupied by natural predecessors. However, in a complete denture patient where there are no previous records such as photographs or dental casts, it is difficult to determine where and which size and shape the denture teeth should be used in complete dentures placed to satisfy the patient’s esthetics emands and functional requirements. Many anatomic landmarks have been used as guides towards artificial tooth selection in edentulous patients. Studies investigated the reliability of some of the routinely used anatomic landmarks including width of the mouth, interalar width, bizygomatic width and interpupillary distance. It was concluded that these relationships might be used as references if applied in combination, although racial and gender differences were detected when anatomic measurements were evaluated individually. The relationship between the width of a central incisor and the bizygomatic width (1:16) is commonly used to determine the size of the maxillary anterior teeth The intercondylar distance remains fairly static throughout life . The intercondylar distance was correlated with upper and lower intercanine distance. According to this study, intercondylar distance can be used for selecting the both maxillary & mandibular anterior six teeth in complete dentures. The objective of the present study is to see if this finding is applicable to our local patients also.
This Cross-sectional comparative study was conducted at institute of dentistry, Liaquat University of Medical and Health Sciences Jamshoro/Hyderabad, from August 2009 to January 2010. One hundred fully dentate students irrespective of their gender within the age group of 20 to 25 years were included for the study purpose. The students with attrition of canines, orthodontic appliances, history of facial alterations, crown & bridge work, & TMD were excluded from the study. The purpose of the study was explained & written consent was taken from each individual.
Demographic information like age and sex were recorded. Selection of subjects was on clinical basis. Upper and lower arch impressions were taken in irreversible hydrocolloid (fast setting alginate name: phase plus by Zhermack Spa) by using stock trays. Dental cast were made using dental stone type IV (Elite Rock Zhermack). Vernier Caliper was used to measure the following linear distances on the cast: including, linear distance between the cusp tips ofmaxillary canines; linear distance between the cusp tips of mandibular canines.(FigureNo 1)
Intercondylar distance was measured using arbitrary face bow (Hanau-H2) at rest position. Fork was attached to the teeth with silicon (Elite H-D+: Zhermack Spa) impressionmaterial. Hinge axismarksweremade 13mm anterior to the upper border on the tragus canthus line on both sides of the face.Themarkwas confirmed by placing the middle fingers of both hands over the marks & students were advised to open & close the jaw by 20 mm, the tactile sensation of rotating condyle confirmed thehinge axis location. The face bow was assembled by inserting the fork intraorally & placing the condylar rodsover the hinge axis marks. Thereafter, face bow is removed from the face without changing the position of condylar rods & the distance between the two condylar rods was measured in millimeters with the help of Vernier Caliper. (Figure No 3) Every distance was measured three times to ensure the accuracy and mean taken. Data obtained was recorded and then subjected to statistical analysis.
Quantitative variables were presented as mean and ± standard deviation. A qualitative variable like sex was presented as frequency and percentages. Pearson’s correlation coefficient was used to determine the correlation among maxillary intercanine and intermolar distance, mandibular intercanine distance with.
Total 100 fully dentate students were enrolled in this study based on certain inclusion and exclusion criteria. Out of 100 students, 86(86.0%) were males and 14(14.0%) were females & mean age was 23.80 1.10 years (n =100). (Table 1)
In this study theMean intercondylar distance (Range) was 128.51 1.99 (n = 125 to 132), mode was 130.0 and medianwas 130.TableNo. (Table 2)
The mean of Maxillary intercanine distance was 29.09 1.44 (25 32). Whereas ,Mean of Mandibular intercanine distancewas 20.0 1.01(17 22).(TableNo 4)
A two-tailed significant Pearson correlation coefficint (r) test was performed to determine the relationship of intercondylar distance with intercanine distance. The highest correlation was found between Maxillary Intercondylar Distance and Maxillary Intercanine Distance (r = 0·72, P=<0·0001), Intercondylar Distance and Mandibular Intercanine Distance (r = 0.309, p = 0.002) (Table 5).
Many attempts have been made to quantify the selection of anterior teeth for removable prosthesis, but little agreement on an effective method has been reached. In this study effort has been made to investigate the relation between inter-condylar width & inter-canine distance in a different sample group( i:e dental students). Selected group of students comprised of 86(86%) males and 14(14%) females. The age range was from 21 years to 25 years. students younger than 20 years of age were not included since the intercanine & intermolar width of both arches increase significantly between the 8 to 20 years of age In the present study, the mean intercondylar distance was higher than the values reported by Keshvad et al , Biserka Lazi et al and Shaikh IA & Qamar K. Higher value of mean ICW represent dominant 86(86%) male participation in the study. Nevertheless, mean ICW for males reported by Biserka Lazi et al is in accordance to this study. When the subjects were separated by gender, a higher mean of intercondylar distance was found for males than for females. Variation based on gender has also been reported by Biserka Lazi et al and Keshvad et al . All of these studies showed a higher mean intercondylar distance ofmales compared to that of females. The mean maxillary intercanine distance of subjectsin the present study was almost similar to Keshvad et al , but was less to the values reported by Gomes et al, and greater than that reported byVarjao et al andB.Rai at al There was significant difference between the mean intercanine distance measurements in relation to gender. Means for intercanine distancemeasurementswere a little higher for males than females. This finding is in accordance with the study carried out byVarjao et al and Keshvad et al. Themeanmandibular intercanine distance of subjects in the present study was less to the value reported by Keshvad et al and B.Rai et al In the present study the ratio between the mean intercondylar andmaxillary intercanine distance is 1:4.41, while ratio between the mean intercondylar and mandibular intercanine distance is 1: 6.42,which are higher to the values reported by other studies. The above higher ratiowere the representation of the higher values for intercondylar & inter-canine distances that is the reflection of dominant (86%) male students participation in this study The results of this study suggest that there is significant correlation exist between the intercondylar distance which remains fairly stable throughout the life & inter-canine distance, this relationship is valuable & practicable for selection & arrangement of artificial teeth. Clinically, the estimated intercanine distance can be obtained by dividing the distance between two condylarrods of the face-bow with 4.41 for maxillary case & 6.42 formandibular case.However, this method is an adjunct to other availablemethods&is not suggested as an exclusive and stand-alone method. The limitation of this study is that no skeletal & ethinic variations were addressed to make this method more scientific
Following conclusions can be drawn from the current study:
Intercondylar distance and maxillary intercanine and mandibular intercanine distances show a positivesignificant correlation and the ration obtained between these variables may be used for the selection & arrangement of artificial teeth
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