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Table of Contents   
ORIGINAL RESEARCH  
Year : 2012  |  Volume : 23  |  Issue : 1  |  Page : 53-58
The crown angulations and inclinations in Dravidian population with normal occlusion


1 Department of Orthodontics, King Saud University Dental College and Hospital, Riyadh, Saudi Arabia
2 Department of Oral and Maxillofacial Surgery, Riyadh Colleges of Dentistry and Pharmacy, Riyadh, Saudi Arabia
3 Department of Orthodontics, Sri Venkateshwara Dental College and Hospital, Chennai, India

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Date of Submission21-Oct-2010
Date of Decision21-May-2011
Date of Acceptance08-Nov-2011
Date of Web Publication26-Jul-2012
 

   Abstract 

Background: There has always been a constant search for the definition of idealistic and realistic orthodontic treatment goals for different ethnic groups around the world. This study was hence devised to study the mesio-distal angulations and labio-lingual inclinations of the clinical crowns in Dravidian population with pleasing profiles and non-orthodontic normal occlusion.
Materials and Methods: Forty dental casts from a Dravidian sample (21.5 years) with Class I canine and molar relation; normal maxillo-mandibular relationship; well-aligned arches; with no dental anomaly, restorations or attrition; no history of previous orthodontic treatment, and exhibiting normal growth were studied. A custom-made tip-torque device was used to measure the crown angulations and inclinations. The arithmetic mean and standard deviations for each tooth type were compared with those of Andrew's Caucasian norms using Student's 't' test.
Results: The study group exhibited statistically significant decrease in crown angulation (mesial tip) and increased labial crown torque in both upper and lower anteriors. The lower anteriors exhibited distal crown tip while the posteriors were significantly tipped more mesially. All the posteriors demonstrated increased lingual crown torque.
Conclusion: Tip and torque modifications are suggested for the fine finishing and easy retention of occlusion in Dravidians while using straight wire appliance.

Keywords: Angulation, Dravidian, ethnic, inclination, normal occlusion, tip, torque

How to cite this article:
Kannabiran P, Thirukonda GJ, Mahendra L. The crown angulations and inclinations in Dravidian population with normal occlusion. Indian J Dent Res 2012;23:53-8

How to cite this URL:
Kannabiran P, Thirukonda GJ, Mahendra L. The crown angulations and inclinations in Dravidian population with normal occlusion. Indian J Dent Res [serial online] 2012 [cited 2019 Feb 17];23:53-8. Available from: http://www.ijdr.in/text.asp?2012/23/1/53/99039
Selection of an appropriate bracket prescription for any particular individual or population facilitates the quality of finish and the obligatory time to achieve the objectives. [1] Over 30 prescriptions are commercially available. Choosing an appropriate one for a given population needs methodical research. Although craniofacial and dental features of "well-balanced faces" of two racially diverse groups are fundamentally different, [1],[2] similarity is evidenced within races. [1],[3] Hence choosing prescriptions that might suit most people of one particular race becomes prudent for consistently achieving good results.

Dempster et al.[4] studied the inclination of the long axis of teeth in normal occlusion, found that all teeth are arranged at an angle to the occlusal plane and each has an optimum inclination labiolingually to best perform its individual and collective functions. Andrew (1960-1964) observed significant consistency in arch co-ordination and spatial relationship of teeth to the occlusal plane and proposed that nonorthodontic normal occlusion could serve as an orthodontic treatment goal. [5] Evidence suggests a positive clinical significance of his hypothesis. [6]

Ethnically, Dravidians are considered the aboriginal inhabitants of Indian peninsula and presently predominant in the southern and eastern parts of India, in Sri Lanka and Maldives. Moreover, in a study conducted among 10 Asian countries, Dravidians were found to be connected with the other Indian populations and also with people of Malaysia, Singapore and China. [7] They are claimed to be genetic intermediaries between Europeans and East Asians. [8] Till date, there is no direct comparison of occlusal parameters of Dravidians to Caucasians based on whom the bracket prescriptions were given. Consequently, a measurement study was designed to study the occlusal characteristics and ensure the consistency of results with the Caucasian norms. The primary objective of this study is to determine the need for finishing bends that might be required to attain optimal results in Dravidian patients.


   Materials and Methods Top


This study was conducted in Chennai, a major city in South India, predominated by short, dark-skinned Dravidian population. Stone casts of 40 subjects (study group) collected over an 18-month period by screening over 3500 candidates from six higher secondary schools; students, staff, and patients at Ragas Dental College Hospital, Chennai. Selection criteria included: Dravidians (ethnicity verified to three generations) with Class I canine-molar relations; normal overjet-overbite; well-aligned arches (no spacing, rotation, crowding); full complement of permanent dentition, caries-free; no supernumerary teeth; pleasing facial profiles, no history of previous orthodontic treatment and normal growth, aged between 13 and 30 years (mean 21.5 years).

Dental stone (MAARC, Orthocal Stone Plaster, Type V, Mumbai, India) casts were made from alginate impressions (Zelgan 2002, Dentsply, India Pvt. Ltd.). Functional Occlusal Plane (FOP) was formed by the three most occlusally located cusps of maxillary first molars and premolars as described by Ross. [9] The maxillary cast base was trimmed parallel to the FOP and transferred to the mandibular cast mounted in centric occlusion. A single examiner drew the Facial Axis of Clinical Crown (FACC) for each tooth using a 0.5-mm lead pencil. Using a digital caliper (Aerospace, China) (0.001 accuracy), midpoint of FACC line was marked as Facial axis (FA) point. Overjet (mm) was measured between the labial surface of lower and palatal surface of the corresponding upper incisor; overbite (mm) was the vertical overlap of upper incisor over the labial aspect of lower incisor. Curve of Spee (mm) was measured as the distance between buccal cusp of premolar and an acrylic template made to rest upon the lower anteriors and second molar representing the occlusal plane.

A custom-made tip-torque device [Figure 1], a modification of Mestriner et al.[10] design was used to measure the angulation and inclination of all the clinical crowns on dental casts. Crown angulation is the angle between FACC of each crown and a line perpendicular to the occlusal plane [Figure 1]. The pointer-arm was adjusted to parallel the FACC of each crown. The crown angulation was considered positive if the occlusal portion of FACC is mesial to the gingival portion, negative if distal. Crown inclination is the angle between a line perpendicular to the occlusal plane and a line parallel to the FACC. The pointer-arm was adjusted to be parallel and tangent to the FACC at the FA point, and the inclination of the crown was read on the protractor [Figure 2]a and b. All readings were made with the cast mounted on the base of the device placed over a flat table with the examiner seated directly facing the protractor on the movable datum adjusted to the eye-level of the examiner to avoid parallax error. Ten percent of the sample was randomly measured to rule out intra-operator and inter-operator errors.
Figure 1: The tip-torque device showing crown angulation measurement

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Figure 2(a, b): Crown inclination measurement

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Arithmetic means and standard deviations were calculated for angulation and inclination of each tooth using SPSS software (SPSS Inc., Chicago, IL) This data was compared with Andrews' data (mean±SD) (control group) using Student's 't ' test [GraphPad QuickCalcs Software, Inc., CA]. Ninety-five percent confidence interval was found. Although the Andrew's straight wire appliance was based upon the research done in 1964, the values available for comparison were only those published in 1984. [5]


   Results Top


The mean and standard deviation were tabulated for each tooth type [Table 1], [Table 2], [Table 3] and [Table 4]; [Figure 3], [Figure 4], [Figure 5] and [Figure 6]. Random error for angulation was 1.20°±0.50° and for inclination 0.76° ± 1.95. No systematic errors found. Mean overjet (1.70 ± 0.53 mm), overbite (2.16 ± 0.77 mm) and curve of Spee (1.33 ± 0.52 mm) correlated well with Andrews' norms (P<0.05). [5]
Table 1: Upper crown angulations

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Table 2: Upper crown inclinations

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Table 3: Lower crown angulations

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Table 4: Lower crown inclinations

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Figure 3: Upper crown angulation

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Figure 4: Upper crown inclination

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Figure 5: Lower crown angulation

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Figure 6: Lower crown inclination

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Angulations of maxillary incisors (CI 3.53 ± 2.43; LI 7.64 ± 4.92) and first premolar (2.36 ± 4.43) correlated well with Andrews data (CI 3.59 ± 1.65; LI 8.04 ± 2.80; I PM 2.65 ± 1.69). Canine had smaller mesial angulation (4.74 ± 4.64) as compared to Caucasian norm (8.40 ± 2.97). The second premolar, first and second molar angulations were significantly higher (IIPM 4.08 ± 3.32; IM 8.14 ± 3.93; IIM 4.17 ± 7.52) than Andrew's findings (IIPM 2.82 ± 1.52; IM 5.73 ± 1.90; IIM 0.39 ± 5.69). Upper second molar angulation (4.17 ± 7.52) was lesser than that of the first molar (8.14 ± 3.93), yet the difference (-4 degrees) remained comparable with that of the Caucasians (I M 5.73 ± 1.90; II M 0.39 ± 5.69). The angulations of maxillary posteriors showed progressively increasing positive angulations (IPM 2.36 ± 4.43; IIPM 4.08 ± 3.32; IM 8.14 ± 3.93). The lower premolars (IPM 1.20 ± 3.66, IIPM 2.18 ± 3.21) exhibited comparable mesial angulations (P≥0.05), while all the other lower teeth significantly differed from the Caucasian norms. The lower anteriors exhibited mild distal crown tipping (CI −0.43 ± 2.93; LI -1.24 ± 3.48; C −0.15 ± 3.87) in contrast to the Caucasians (CI 0.53 ± 1.29; LI 0.38 ± 1.47; C 2.48 ± 3.28) (P<0.05).

Upper crown inclinations in this study were significantly greater. All maxillary anteriors showed increased buccal crown torque (CI 8.99 ± 6.39; LI 7.86 ± 5.80; C -5.15 ± 4.01) when compared to the Andrews data (CI 6.11 ± 3.97; LI 4.42 ± 4.38; C −7.25 ± 4.21) while the upper molar showed increased lingual crown torque (−14.06 ± 6.66 as to −11.53 ± 3.91). The upper first and second premolar inclinations (IPM −8.25 ± 5.19; IIPM -9.25 ± 5.36) correlated well with the Caucasian standards (IPM −8.47 ± 4.13; IIPM −8.78 ± 4.13) (P≥0.05). Contrarily, the lower anteriors in the current study had significantly lesser lingual crown torque (CI 3.90 ± 6.60; LI −0.18 ± 6.20; C −8.83 ± 5.17). The lower posteriors showed increased lingual crown torque (IPM −21.55 ± 4.62; IIPM −25.06 ± 4.33; IM −33.86 ± 5.82; IIM -37.06 ± 2.05) with maximum difference at the level of first molars (3 degrees). The lower second molar (−37.06 ± 2.05) showed 1 degree more lingual crown torque when compared with the Andrews group (−36.03 ± 6.57), but the difference was found to be statistically insignificant.


   Discussion Top


The present study was designed to determine the crown angulation and inclination in Dravidian samples and to compare this data with the Caucasian norms. This study was comparable with that of Sebata's study [11] on 41 dental casts of Japanese sample, based on which the new Asian norms were derived.

The major challenge had been the development of an adequate methodology that would be capable of yielding reliable values with direct clinical application. The reference plane FOP as described by Ross et al.[9] is found to be stable after the eruption of a complete permanent dentition, [12] easy to detect, intrinsic to the cast itself eliminating any need for adjunctive data. [13],[14] As orthodontists work mainly with dental crowns, the facial surface of the clinical crowns are best suited for assessing the angulation and inclination of all teeth completely erupted into the oral cavity due to easy visualization both clinically and on dental casts. [15]

Determination of buccolingual inclinations of several teeth has been widely investigated. [12],[16],[17] There were two concerns, firstly, how to quantitatively represent inclination of an irregularly convex surface and then, how to enhance reproducibility of the angular measurements made. Some answers were proposed: buccolingual inclination could be represented by a tangent vertical to this surface. For this tangent to represent values with clinical application, the chosen tangency point was the one considered as representative of the bracket location. [10] The vestibular central zone of identical tooth-crown in different individuals is fairly stable and is suitable for the location of preadjusted brackets. [18] In the present study, this was determined by the tip-torque pointer. Secondly, literature provided two solutions for the determination of the second reference line, namely a line perpendicular to the occlusal plane [19] or a line representing the long axis of either the tooth or the clinical crown. [13] But the latter did not present a direct clinical application because it only denoted the dental anatomy but also failed to consider the relationship of teeth with the face or with the occlusion. Hence the reference line that denoted the vertical tangent to the facial surface at FA point and the line perpendicular to the FOP were chosen.

Although variety of inclination determining gauges were designed for both clinical and laboratory purposes, some calculated inclination angles using Pythagoras theorem. [13] while others had hand-held components [5],[15] which posed risk to data reliability and reproducibility. To overcome such practical difficulties in angulation measurements, a custom-made tip-torque device was constructed to enable standardization of both horizontal reference plane (parallel to FOP) and the vertical (perpendicular to FOP). This method was less time-consuming and more accurate.

Upper crown angulation

Of all angles recorded, crown angulation of upper incisors exhibited the maximum correlation with Andrews [5] data while mesial angulation of canine was significantly lesser than the previous studies. [5],[19] This minimizes the need for excessive positive tip in canine brackets in Andrew's and Roth's prescriptions which might tax anchorage. [20] The posteriors showed significantly more mesial angulation. The second premolar and second molar angulations were similar to those of Japanese. [19] The difference between the upper first and second molar angulation was comparable with those of Andrews [5] and Sebata's groups [11] indicating that, though tip of the two teeth differed, the pattern of arrangement remained comparable in all populations. For the second molar, Andrews [5] and Sebata's [11] values were very close but was higher in this study. The angulations of maxillary posteriors showed progressively increasing mesial crown tip abiding by the Andrews' six keys of normal occlusion. [5] Unlike the findings of Currim et al., [21] which showed significantly inreased tip only for second premolar and molar, this study exhibited increased positive tip for all the posterior teeth with maximum tip for first molar. Likewise, Currim et al., [21] also observed lesser tip for lateral incisor while both central and lateral incisor angulations in our group were comparable with the Caucasians. This might have been due to the mixed ethnicity of their sample. [Table 1], [Figure 3]

Upper crown inclination

Similar to the Japanese, [11] Dravidians also had more proclined upper anteriors. The upper canine inclination was more upright, agreeable with Currim et al.[21] The premolar torque were comparable with Andrews [5] while the molar crowns were more lingually inclined. This could probably be due to the difference in arch forms found in different populations. [1],[22] [Table 2], [Figure 4]

Lower crown angulation

On an average, FACC of lower incisors seemed nearly vertical, yet standard deviations were larger than the mean. Indeed, Andrews also reported large standard deviations. [5] The premolars correlated well with Andrews. [5] Crown angulations of all teeth from lower canine to second molar in the present study fell within the range formed with Japanese [11] values as the upper limit and the Caucasian [5] as the lower. It could be inferred that these teeth possessed more mesial angulations than the Caucasians but lesser than the Japanese population. [11] In the mandibular arch, our data was close to Andrews', with a difference of 1°-3°. The anterior teeth showed distal tip like the Sebata's sample [11] while posterior teeth were more mesially inclined. [Table 3], [Figure 5]

Lower crown inclination

In Caucasians the mandibular incisors exhibit torque in the range of 0 to −1° (buccal root torque), indicating an upright position of these teeth. In contrast, in this study, the lower incisors exhibited positive inclination like the Japanese (central incisor with Sebata's data; [11] lateral incisors and canines with Watanabe's data [19] ). Generally, it is of a consensus that all mandibular incisors exhibit same torque. Yet, it has been demonstrated that there was a small variation between the torque of these two teeth. [10],[23] The present study showed 4 degrees torque difference between the mandibular central and lateral incisors which is in agreement with Ugur [23] and Mestiner. [10] Yet, it could be erroneously assumed that mandibular lateral incisor is more upright than the relatively proclined mandibular central incisor. It would be appropriate to understand the variations in the crown-root (collum) angle [24] and also the anatomical difference of the buccal surface. [25] The buccolingual diameter of the mandibular lateral incisor is slightly greater than that of the mandibular central incisor (0.4 mm on average). [25] This anatomical difference might have placed the lateral incisor's tangent of the buccal surface more vertically than the central incisor. Similar to the Andrews [5] group all the lower posteriors showed progressively increasing lingual crown torque, except the second molar which showed comparable inclination although with great variability as in previous reports. [5],[11] [Table 4], [Figure 6]

An interesting finding in this study was perhaps the great variation found in the normal occlusion sample. Despite the sample denoting a selected and rare group of individuals, the inclinations of the teeth, incisors and canines for example, ranged from negative (lingual crown torque) to positive values (buccal crown torque). The crown angulations of the maxillary incisors were comparable with those of Andrews [5] but all the other teeth except canine showed greater mesial crown angulation. The crown inclinations were comparatively greater than those of Andrews [5] but showed correlation with Sebata's values, [11] which was the result of the study conducted in 1989 in Japanese population following Andrew's methodology. [5] As stated in previous studies, [11],[19] Japanese population was characterized by dental proclination with a tendency for bimaxillary dentoalveolar protrusion and hence a mild convex profile which was considered to be normal for that race. Our study was conducted in Dravidian population who were also characterized by convex facial profile and a bimaxillary protrusive tendency. This explains the increased labial crown inclination of both upper and lower anteriors.

As compared to similar researches [5],[21] in the past, a notable feature of this study was the methodology adopted for measurements which enhanced the validity and reproducibility of data. The device could be used for determining the angular changes of any tooth in either arch on any dental casts even during treatment. 0.032" straight wire stylus in the tip-torque indicator made minimal surface-contact with the tooth to be measured enhancing precision. Moreover, unlike in other studies [5],[15] this stylus was small enough to adapt into the buccal groove of molars which represented their facial axis.

The variations in our results when compared with those available in literature could be due to variations in the biological variables such as, crown morphology, (facial contour) difference among individuals or among populations and the crown-root angle which differed among teeth of the same type, as suggested by Germane et al.[17],[26] Being a cross-sectional study, growth or age-related occlusal changes were not assessed but it is of limited importance when the sample had full complement of permanent dentition at the time of study. No attempt was made to analyze the data on sex and growth patterns, although Janson [12] reported an increased buccal crown inclination of the maxillary posteriors in vertical growers and Ross [9] demonstrated significant difference in upper incisor inclinations with growth patterns. Thus, the present sample provides an insight on the variability in the occlusal arrangement among different racial and ethnic groups.


   Conclusions Top


Within the given consensus of this study, it could be concluded that while using Andrew's straight wire appliance:

  • Maxillary incisors and first premolar angulations need no tip modification. Upper canine needs decreased tip while the second premolar, first and second molars need increased tip.
  • All the maxillary anteriors require increased buccal crown torque. The molar tubes need increased buccal root torque. The premolars need no torque alteration.
  • Lower crown angulations, indicate lesser mesial tip for anterior brackets while premolar brackets need no change. Mandibular molars need increased mesial tip.
  • The mandibular central incisors need lesslingual crown torque; premolars and first molar need increased buccal root torque; second molar needs no torque modification.


Although this study establishes reference values to help orthodontist in treatment planning and arch stabilization in Dravidians, further study with larger sample size is warranted before the results could be extrapolated to the development of a new prescription for Dravidian population. Yet, considering the major findings, it could be suggested that among the currently available prescriptions, MBT [27] prescription is the closest match for treating Dravidian population.


   Acknowledgment Top


I wish to acknowledge Dr.R.Kannabiran, Mrs. Sarala Devi, Anand Engineering works, Chennai, Dr. D. Sankar for their invaluable support which made this study possible.

 
   References Top

1.Bai D, Luo SJ, Chen YX, Xiao LW. The clinic skill in fixed appliance based on characteristics of Chinese normal occlusion. Hua Xi Kou Qiang Yi Xue Za Zhi 2005;23:32-4.  Back to cited text no. 1
[PUBMED]    
2.Lew KK. Cephalometric ideals in Chinese, Malay and Indian ethnic groups. Asian J Aesthet Dent 1994;2:35-8.  Back to cited text no. 2
[PUBMED]    
3.Al-Abdwani R, Moles DR, Noar JH. Change of incisor inclination effects on points A and B. Angle Orthod 2009;79:462-7.  Back to cited text no. 3
[PUBMED]    
4.Dempster WT, Adams WJ, Duddles RA. Arrangement in the Jaws of the roots of the teeth. J Am Dent Assoc 1963;67:779-97.  Back to cited text no. 4
[PUBMED]    
5.Andrews LF. Straight Wire -The Concept and Appliance. San Diego, Ca: L. A. Wells Co.; 1989. p. 92-107.  Back to cited text no. 5
    
6.Roth R. The straight-wire appliance 17 years later. J Clin Orthod 1987;21:632-42.  Back to cited text no. 6
    
7.Available from: http://timesofindia.indiatimes.com/india/Ancestors-of-Chinese-came-from-India-Study/articleshow/5328596.cms. [cited in 2011].  Back to cited text no. 7
    
8.Bamshad MJ, Watkins WS, Ostler CT, Batzer MA, Jorde LB. Human population genetic structure and inference of group membership. Am J Hum Genet Mar 2003;72:578-89.  Back to cited text no. 8
[PUBMED]    
9.Ross VA, Isaacson RJ, Germane N, Rubenstein LK. Influence of vertical growth pattern on faciolingual inclinations and treatment mechanics. Am J Orthod Dentofacial Orthop 1990;98:422-9.  Back to cited text no. 9
[PUBMED]    
10.Mestriner MA, Enoki C, Mucha JN. Normal torque of the buccal surface of mandibular teeth and its relationship with bracket positioning: A study in normal occlusion. Braz Dent J 2006;17:155-60.  Back to cited text no. 10
[PUBMED]    
11.Sebata E. An orthodontic study of teeth and dental arch form on the Japanese normal occlusions (author's transl). Shikwa Gakuho 1980;80:945-69.  Back to cited text no. 11
[PUBMED]    
12.Janson G, Bombonatti R, Cruz KS, Hassunuma CY, Del Santo M Jr. Buccolingual inclinations of posterior teeth in subjects with different facial patterns. Am J Orthod Dentofacial Orthop 2004;125:316-22.  Back to cited text no. 12
[PUBMED]    
13.Shah N, Spary DJ, Rock WP. A jig for measuring incisor inclination. Eur J Orthod 2005;27:252-7.  Back to cited text no. 13
[PUBMED]    
14.Ferrario VF, Sforza C, Colombo A, Ciusa V, Serrao G. Three-dimensional inclination of the dental axes in healthy permanent dentitions: A cross-sectional study in a normal population. Angle Orthod 2001;71:257-64.  Back to cited text no. 14
[PUBMED]    
15.Richmond S, Klufas ML, Sywanyk M. Assessing incisor inclination: A non-invasive technique. Eur J Orthod 1998;20:721-6.  Back to cited text no. 15
[PUBMED]    
16.Ghahferokhi AE, Elias L, Jonsson S, Rolfe B, Richmond S. Critical assessment of a device to measure incisor crown inclination. Am J Orthod Dentofacial Orthop 2002;121:185-91.  Back to cited text no. 16
[PUBMED]    
17.Germane N, Bentley B, Isaacson RJ, Revere JH, Jr. The morphology of canines in relation to preadjusted appliances. Angle Orthod 1990;60:49-54.  Back to cited text no. 17
    
18.Bai D, Xiao L, Chen Y. A study on central zone contour of tooth-crown vesticular surface among young people with normal occlusion. Sheng Wu Yi Xue Gong Cheng Xue Za Zhi 2002;19:287-90.  Back to cited text no. 18
[PUBMED]    
19.Watanabe K, Koga M. A morphometric study with setup models for bracket design. Angle Orthod 2001;71:499-511.  Back to cited text no. 19
[PUBMED]    
20.Bennett JC, McLaughlin RP. Controlled space closure with a preadjusted appliance system. J Clin Orthod 1990;24:251-60.  Back to cited text no. 20
[PUBMED]    
21.Currim S, Wadkar PV. Objective assessment of occlusal and coronal characteristics of untreated normals: A measurement study. Am J Orthod Dentofacial Orthop 2004;125:582-8.  Back to cited text no. 21
[PUBMED]    
22.Kook YA, Nojima K, Moon HB, McLaughlin RP, Sinclair PM. Comparison of arch forms between Korean and North American white populations. Am J Orthod Dentofacial Orthop 2004;126:680-6.  Back to cited text no. 22
[PUBMED]    
23.Ugur T, Yukay F. Normal faciolingual inclinations of tooth crowns compared with treatment groups of standard and pretorqued brackets. Am J Orthod Dentofacial Orthop 1997;112:50-7.  Back to cited text no. 23
    
24.Bryant RM, Sadowsky PL, Hazelrig JB. Variability in three morphologic features of the permanent maxillary central incisor. Am J Orthod 1984;86:25-32.  Back to cited text no. 24
[PUBMED]    
25.Bishara SE, Jakobsen JR, Abdallah EM, Fernandez Garcia A. Comparisons of mesiodistal and buccolingual crown dimensions of the permanent teeth in three populations from Egypt, Mexico, and the United States. Am J Orthod Dentofacial Orthop 1989;96:416-22.  Back to cited text no. 25
[PUBMED]    
26.Germane N, Bentley BE, Jr., Isaacson RJ. Three biologic variables modifying faciolingual tooth angulation by straight-wire appliances. Am J Orthod Dentofacial Orthop 1989;96:312-9.  Back to cited text no. 26
    
27.McLaughlin RP, Bennett JC, Trevisi HJ. Systemized Orthodontic Treatment Mechanics, Mosby Elsevier;2001: p. 9-10, 33.  Back to cited text no. 27
    

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Correspondence Address:
Praveena Kannabiran
Department of Orthodontics, King Saud University Dental College and Hospital, Riyadh
Saudi Arabia
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0970-9290.99039

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    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4]

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