A study on incidence of primary incisor spacing in school children of Chidambaram.
Spacing has been usually considered as an essential feature of the ideal deciduous dentition. Spacing in the deciduous teeth has been called "developmental spacing" by Graber (1985). (1) Korkhaus and Neumann (1931) (2) concluded that the presence of physiological spacing indicated a marked difference between the crown breadth of deciduous and permanent incisors. Baume (3) concluded that there is no physiologic spacing after eruption of primary teeth and emphasized that one has either a 'spaced' or a 'closed' dentition. Spacing has been classified into two types: (1) Generalized and (2) Primate.
The generalized spacing appears amongst all the deciduous teeth including the two deciduous central and two deciduous laterals, both, right and left sides. Primate spacing appears mesial to the upper deciduous canine and distal to the lower deciduous canine. In closed primary dentitions, the permanent mandibular lateral incisors emerge and the primary mandibular canines are moved laterally. Thus a space is created that enables the permanent maxillary lateral excisors to emerge in to a favourable alignment. This is referred to as secondary spacing and was first described by Baume. (3) Secondary spacing also occurs when the permanent mandibular central incisors are emerging.
The combined mesiodistal width of the permanent incisors is more than that of the deciduous incisors. This size differential is known as incisor liability. (4) A favourable incisor liability exists when the primary spacing of the spaced dentition is sufficient to allow for the eruption of the permanent incisors without crowding. (4) An impossible situation exists when the incisor liability is of such magnitude that growth and development will never be able to meet the space demands required by the permanent incisors. Such patients are doomed severe crowding and irregularity from the onset.
AIMS AND OBJECTIVES
As racial differences exists in dento-facial morphology, tooth size and eruption pattern, knowledge based on western studies cannot be applied to Indians. (5,6,7,8) Since dental spacing and crowding pattern varies not only among different races, but also among sub-groups of major racial groups, the necessity for obtaining information amongst sub-groups of Indians is evident. (2,9) The present study is therefore planned to find out the incidence and pattern of primary incisor spacing and measurement of incisor liability in the school children of Chidambaram between ages of three and five years.
MATERIALS AND METHODS
One hundred school children from seven schools in Chidambaram comprised the population of this study. 48 boys and girls in the age group of 3 to 5 years were included.
The children were selected on the basis of the following criteria.
(1) There was a full complement of deciduous dentition both in the maxilla and the mandible.
(2) They showed normal occlusion of teeth and pleasing facial profiles.
(3) They showed normal growth and development.
(4) The children did not show any dental rotation, crowding, open bite or cross bite.
(5) Absence of proximal caries of teeth.
(6) Absence of malformed teeth.
IMPRESSION MAKING AND PREPARATION OF THE STUDY MODELS
After clinical examination of all selected cases, good vestibular maxillary and mandibular full mouth alginate impressions were taken for each child and then models are prepared.
The measurement were made on the stone casts using Vernier Caliper (Dentarum, West Germany), reading to the nearest 0.01mm. The spaces between the deciduous central incisors were individually measured on the maxillary and mandibular casts on the right and left side of each patient. The mesiodistal width of each of the maxillary and mandibular primary incisors was measured separately at the maximum width of each tooth using a pair of sharp dividers.
Intra-oral periapical radiographs of the maxillary and mandibular permanent incisors were taken using standardised short cone technique. The maximum mesiodistal widths of the permanent central and lateral incisors of both the right and left sides were measured from the radiographs using the Vernier Caliper.
The radiographic error was corrected using Huckaba formula for which one deciduous tooth was measured both in the radiograph and in the model.
Huckaba (10) formula = X = X'Y/Y'
Where, X = actual width of the permanent tooth
X'= apparent width of the permanent tooth
Y = actual width of the deciduous tooth
Y'= apparent width of the deciduous tooth.
1. MAXILLARY SPACING
Mean and standard deviation of spacing between primary central incisors, spacing between primary right central and lateral and spacing between left central and lateral primary incisors in maxilla. (TABLE I)
There is significance in the amount of maxillary primary incisor spacing with respect to right and left sides but no significance in Right spacing Vs Left spacing.
2. Mean and standard deviation of spacing between primary central incisors, spacing between right central and lateral primary incisors in maxilla by sex.
There is significance in maxillary primary central incisor spacing with respect to sex but there is no significance in right spacing and left spacing with respect to sex. (TABLE II)
3. Mean and standard deviation of spacing between primary central incisors by age group. (TABLE III)
There is no significance in spacing, right spacing and left spacing in various age groups.
4. Mean and standard deviation of maximum mesiodistal tooth size of deciduous central incisor with respect to right. and Left sides. (TABLE IV)
5. Mean and standard deviation of maxillary right and left central and lateral primary incisors by sex.
There is no significance in the mesiodistal tooth size of Rt and Lt lateral incisors with respect to males and females. (TABLE V)
6. MANDIBULAR SPACING:
Mean and standard deviation of spacing between primary central incisors, spacing between right central and lateral primary incisors and left central and lateral primary incisors in mandible. (TABLE VI)
There is no significance in primary incisor spacing with respect to right and left sides in the mandible.
7. Mean and standard deviation of spacing between primary central incisors, spacing between right central and lateral primary incisors in mandible by sex. (TABLE VII)
There is no significance in mandibular primary incisor spacing with respect to sex.
8. Mean and standard deviation of spacing between primary central incisors, spacing between right central and lateral primary incisors and left central and lateral primary incisors in mandible by age group. (TABLE VIII)
There is significance in spacing between central incisors with respect to age group, but no significance in right and left spacings with respect to age group.
9. Mean and standard deviation of maximum mesiodistal tooth size of deciduous mandibular central incisors. (TABLE IX)
There is no significance in the mesiodistal tooth size of deciduous mandibular central incisors with respect to the right and left sides.
10. Mean and standard deviation maximum mesiodistal tooth size of manibular deciduous incisors by sex. (TABLE X)
There is significance in the mesiodistal tooth size of right and left deciduous central incisors with respect to males and females but not in right and left deciduous lateral incisors.
11. MAXILLA Vs MANDIBLE:
Mean and standard deviation of spacing between primary central incisors, right central and lateral primary incisors and left central and lateral primary incisors maxilla and mandible. (TABLE XI)
There is significance in primary incisors spacing with respect to maxillary and mandibular arches.
12. INCISOR LIABILITY:
There is no significance in incisor liability with respect to upper and lower arches. (TABLE XII)
The findings of the present study indicated that primary incisor spacing appeared to be a more common feature of the normal deciduous dentition of Chidambaram school children even though there were a few cases devoid of any spacing. Foster and Hamilton (1969) (11) reported that only 1% of British children had no spaces. Bokyo (1968) (12) recorded 2% of his Burlington sample as having no spaces. In comparison, the present study showed more cases with no primary incisor spacing in the maxillary and mandibular arches respectively. White and Gardiner (1976) (13) reported that failure of incisor spacing occurs in 20% of cases before 5 years of age and usually indicated crowding in the permanent dentition. Bonnar (1960) (14) reported on the spacing of the incisor teeth in the primary dentition in 65 children. It was found that only 17% of the children had spacing between all the upper and lower primary incisor teeth.
In the present study, the amount of interdental spacing of the primary incisors ranged between 0 and 3.5 mm in the maxillary arch with an average of 0.9mm and between 0 and 3mm in the mandibular arch with an average of 0.8mm. This was seen to be low when compared to Graber and Swain's finding (1965). (4) The Chidambaram school children showed no difference with respect to sex in the amount of primary incisor spacing in the mandibular arch. But in the maxillary arch, the amount of interdental spacing between the two primary central incisors was more in case of females when compared to males. This was found to be statistically significant (p < 0.05). There were no differences with respect to sex in the amount of interdental spacing between the right and left maxillary lateral primary incisors. They showed no differences between the right side and the left side in the amount of primary incisor spacing in the mandibular arch. In Kaufman and Koyoumjisky's (1967) (2) findings, the Israeli children showed larger primary anterior spacing in males than in females. Similarly, in Joshi and Makhija's (1984) (2) study, the Gujarat children had more amount of primary teeth spacing in males than in females.
The mesiodistal width of mandibular primary central incisors was seen to be more in males when compared to females in the present study.
There was a larger difference in the size of the maxillary permanent incisors compared to their deciduous predecessors than there was of the mandibular permanent incisors and their predecessors in the present study when compared to Seipel (1946). (15)
SUMMARY AND CONCLUSION:
The pattern of spacing in the normal deciduous dentition of 48 boys and 52 girls in the age range of 3-5 yrs Chidambaram, South India was studied.
The following conclusions were drawn from the observations:
1. The Chidambaram children presented with 73% and 63% spacing in the maxilla and mandibular arches especially in the primary dentition.
2. 27% and 37% of the cases were seen to have primary incisor crowding in the maxillary and mandibular arches respectively.
3. The amount of primary interdental incisor spacing was found to be 0.9mm in the maxillary arch.
4. The amount of maxillary primary interdental spacing was similar in the 5 year and the 3-4 years age groups.
5. The amount of interdental spacing between the lower central primary incisors was more in the 5 year age group than in the 3-4 year age group.
6. The amount of interdental spacing between the lower central and lateral primary incisors both on the right and left side were seen to be similar in the 5 year and 3-4 year age groups.
7. The amount of interdental spacing between the two primary maxillary central incisors was more in case of females than in males.
8. There were no sex differences in the amount of interdental spacing between the primary maxillary right central and lateral incisors and the left central and lateral incisors.
9. There were no sex differences in the amount of mandibular primary interdental spacing.
10. There were no differences with respect to sex in the mesiodistal width of maxillary primary incisors.
11. The mesiodistal width of mandibular primary central incisors was more in males than in females.
12. There were no sex differences in the mesiodistal width of mandibular lateral primary incisors.
13. There were no differences between the right and the left side in the mesiodistal tooth size of maxillary and mandibular primary incisors.
14. Incisors liability was more in the maxillary arch than in the mandibular arch.
(1.) Graber TM: Orthodontics current principles and techniques, The C.V. Mosby Company, 1985.
(2.) Joshi PG Makija: Some observations on spacing in the normal deciduous dentition of 100 Indian School children from Gujarat, British Society for the studies of orthodontics, 1984; 7-11.
(3.) Baume LJ: Physiological tooth migration and its significance for the development of occlusion. J. Dent. Res. 1950; 29:123, 331-334, 440.
(4.) Graber and Swain: Orthodontics current principles and techniques, The C.V. Mosby Company, 1985.
(5.) Kapoor, DN, Chawala TN: A study of mesiodistal crown width of anterior tooth among North Indians Journal of Indian Dental association, August 1973; 241-245.
(6.) Lavella CLB: Maxillary and mandibular tooth size in different racial groups and in different occlussal categories, American Journal of Orthodontics, Jan 1972; 61(1): 29-36.
(7.) Moorees CFA: The dentition of the growing child. A longitudinal study of Dental Devalopment between 3 and 18 years of age Harward University Press, 1959.
(8.) Moorrees: Normal variation in dental development determined with reference to tooth eruption states, J.Dent. Res. Vol. 1965; 44:161-173.
(9.) Samir E Bishara, Arturo Fernandez, et al: Mesiodistal crown dimensions in Mexico and the United States, Angle Ortho, Oct. 1986; 315-323.
(10.) George V. Huckaba: Arch size analysis of tooth size prediction. Dental clinic of North American, 1964; 431-441.
(11.) Foster and Hamilton: Occlusion in the primary dentition, British Dental Journal, Jan. 1969; 26: 77-79.
(12.) Bokyo DJ: The incidence of primate spaces in fifty three years old children of Burlington study. American Journal of Orthodontics, July 1962; 54(6): 504-527.
(13.) White TC of Gardner: Orthodontics for dental studies 2nd edition, 1967; 36.
(14.) Foster D, Grundy C: Occlusal changes from primary to permanent dentition. British Dental Journal, Jan. 1969; 13(2): 77-79.
(15.) Siepel CM: Variation of tooth position--A biometric study of variation and adaptation in the deciduous and permanent dentition, Swedish Dent. J., Suppliment 1946; 39.
Kannan K S , Rangeeth , Rajvikram , Rajesh R 
Professor and Head 
Department of Pedodontics Thai Moogambigai Dental College and Hospital Chennai
Senior Lecturer 
Department of Orthodontics Thai Moogambigai Dental College and Hospital, Chennai
Email for correspondence:
Received: July 17, 2011
Review Completed: August, 19, 2011
Accepted: September, 22, 2011
Available Online: January, 2012
TABLE--I Mean Std. Dev. Mean Std. Dev. Significance Spacing Vs Rt 0.533 0.772 1.113 0.795 P < 0.01 spacing Spacing Vs Lt 0.533 0.772 1.091 0.781 P < 0.01 spacing Rt Spacing Vs 1.113 0.796 1.091 0.781 NS Lt spacing TABLE--II Male Std. Female Std. Significance mean Dev. Mean Dev. Spacing 0.349 0644 0.744 0.859 P < 0.05 Right Spacing 1.137 0.823 1.087 0.775 NS Left Spacing 1.076 0.913 1.109 0.608 NS TABLE--III 3-4 years 5 years Mean Std. Dev. Mean Std. Dev. Significance Spacing 0.427 0.696 0.631 0.833 NS Right Spacing 1.048 0.743 1.174 0.847 NS Left Spacing 0.361 0.743 1.174 0.847 NS TABLE--IV Upper right central iors Upper left central incisors Mean Std. Dev. Mean Std. Dev. Significance 11.421 0.885 11.474 0.904 NS TABLE--V Mean Std. Dev. Mean Std. Dev. Significance Rt deciduous 6.285 0.501 6.099 0.504 NS central incisor Lt deciduous 6.335 0.583 6.155 0.548 NS central incisor Rt deciduous 5.325 0.508 5.148 0.560 NS lateral incisor Lt deciduous 5.223 0.429 5.087 0.516 NS lateral incisor TABLE--VI Mean Std. Dev. Mean Std. Dev. Significance Spacing Vs 0.686 0.762 0.827 0.699 NS Rt spacing Spacing Vs 0.686 0.762 0.844 0.641 NS Lt spacing Rt Spacing Vs 0.827 0.699 0.844 0.641 NS Lt spacing TABLE--VII MALE FEMALE Mean Std. Dev. Mean Std. Dev. Significance Spacing 0.583 0.745 0.792 0.777 NS Right 0.763 0.639 0.892 0.762 NS Spacing Left 0.816 0.630 0.873 0.661 NS Spacing TABLE--VIII 3-4 yrs 5 yrs Mean Std. Dev. Mean Std. Dev. Significance Spacing 0.361 0.463 0.962 0.859 P<0.01 Right Spacing 0.829 0.705 0.825 0.705 NS Left Spacing 0.808 0.589 0/875 0.689 NS TABLE--IX Lower right central incisors Lower left central incisors Mean Std. Dev. Mean Std. Dev. Significance 8.289 0.747 8.443 0.802 NS TABLE--X Males Females Mean Std. Dev. Mean Std. Dev. Significance Rt deciduous 4.421 0.515 3.861 0.450 p < 0.01 central incisor Lt deciduous 4.171 0.498 3.908 0.424 p < 0.01 central incisor Rt deciduous 4.295 0.377 4.292 0.515 NS lateral incisor Lt deciduous 4.483 0.455 4.340 0.586 NS lateral incisor TABLE--XI Maxilla Mandible Mean Std. Dev. Mean Std. Dev. Significance 0.583 0.772 0.686 0.762 p < 0.02 1.113 0.796 0.827 0.699 p < 0.02 1.091 0.781 0.844 0.641 p < 0.02 TABLE--XII Upper Lower Mean Std. Dev. Mean Std. Dev. Significance 6.074 2.523 4.550 2.595 NS
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|Title Annotation:||Original Article|
|Author:||Kannan, K.S.; Rangeeth; Rajvikram; Rajesh, R.|
|Publication:||Indian Journal of Dental Advancements|
|Date:||Oct 1, 2011|
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