Tara F.doc J Bagh College Dentistry Vol. 25(2), June 2013 Dental anomalies associated Orthodontics, Pedodontics and Preventive Dentistry173 Dental anomalies associated with malocclusion among 13 year old Kurdish students Tara A. Rasheed, B.D.S., M.Sc. (1) ABSTRACT Background: The aim of this national oral health survey was to determine the prevalence of malocclusions due to some anomalies in the dentition among the 13 years old Kurdish students in sulaimani intermediate school. Materials and methods: The total sample was 950 (455 males and 495 females) which assessed by diagnostic set and special instrument. The clinical examination was mainly based on the definitions of Björk et al. Some variables were recorded as present or absent sometimes denoting the tooth or the teeth involved in malocclusion and their distribution according to the whole sample. Results: The results showed that 1)The most common extracted tooth was the mandibular first molar (2.9%). 2) At this age group the most common partially erupted tooth was the maxillary canine (4.2%). 3) The most common unerupted tooth was the maxillary second molars. 4) The most common retained deciduous tooth was the maxillary canine (6.8%), then the maxillary second molars (5.4%).5) Hypodontia as judged clinically was found in 2.1% of the sample affecting one or more permanent teeth. The most common congenitally missing tooth was the maxillary lateral incisor (0.9%), mandibular second premolars (0.4%), and then maxillary second premolar (0.2%). 6) 29.2 % of the sample had one or more rotated teeth. The most common rotated tooth was the mandibular second premolars (5.3%). 7). The sample showed 30.4% with one or more displaced teeth. The most common displaced tooth was the maxillary lateral incisor (8.8%), then the maxillary canine (7.2%). Conclusion: At the age of 13 both males and females show large range of dental anomalies that are better to be controlled. Keywords: Anomalies, sulaimani, hypodontia, congenitally, deciduous. (J Bagh Coll Dentistry 2013; 25(2):173-178). INTRODUCTION Sulaimani lies in the northern mountainous part of Iraq. The main language of the inhabitant people is Kurdish. The total population of Sulaimani City is about 601,705 of whom 13,274 are 13 years of age. Few orthodontic researches have been conducted in this part of Iraq. While dental caries has been regarded as the major dental disease throughout the world, malocclusion is a close runner-up. The morphogenetic nature of most malocclusions assures us that this dento- facial problem will continue to demand the best that dentistry can offer for a long time, indeed ⁽¹⁾. Clearly, there is a need for further epidemiological research aiming to increase the knowledge about the extent of demand for orthodontic treatment ⁽²⁾, therefore, it is of prime importance in diagnosis and treatment planning in Orthodontics or for the development of any national preventive plan for malocclusion. A thorough investigation of the occurrence of these malocclusions among school children would be of major importance in the planning of orthodontic treatment in the Public Dental Health Service. This study was not designed to be carried out on subjects who are still in a mixed dentition stage of development because of the dynamic nature of the mixed dentition stage and because many problems of occlusion in that stage of development are self-correcting ⁽³⁾. (1)Lecturer. Department of Preventive, Orthodontics and Pedodontics, College of Dentistry/ University of Sulaimani It is likewise important to carry out a comparison of the prevalence of malocclusion with different racial groups on an objective basis, since the information they would provide might well throw light on the causes of malocclusion ⁽⁴⁾. The few studies which have been published have dealt with selected sub-populations and it is therefore not known whether the results may be generalized to the total population. Clearly, there is a need for further epidemiological research aiming to increase the knowledge about the prevalence and type of malocclusion as well as the extent of need and demand for orthodontic treatment ⁽²⁾. Although the dental services in Iraq have been in continuous development both in type of the service given and in the size and distribution of the service supplied ⁽⁵⁾, but studies devoted to identify the malocclusion problem in the Iraqi population have been quite few ⁽⁶,⁷⁾. This study was designed to include a sample of (950) of one age group (13 year olds) selected by multi-stage sampling similar to ⁽⁸,⁹⁾ who performed an oral health National study in Iraq. MATERIALS AND METHODS 1. The Sample This study was designed to include a sample of (950) of one age group (13 year olds) in sulaimani intermediate school selected by multi-stage sampling J Bagh College Dentistry Vol. 25(2), June 2013 Dental anomalies associated Orthodontics, Pedodontics and Preventive Dentistry174 2. Instruments and Equipment The following instruments and supplies were used: 1. Plane mouth mirrors 2. Millimeter graded vernier (Inox, Zurcher Modell, Dentaurum 042-751). 3. Metric ruler 4. An instrument designed to measure tooth rotation and displacement modified from ⁽¹⁰⁾ and ⁽⁴⁾. It is 6.5 cm long and consists of two stainless steel rods of 1mm in diameter with rounded ends, and 15º angle between them. 3. Method Examination Area: The students examined were seated in a chair with a high backrest with their head supported in an upright position and the examiner standing in front of the chair ⁽³ ¹¹⁾. Clinical Examination: Anomalies in the dentition: These observations were assessments of the status of individual teeth. Each tooth (and tooth space) is assessed for the conditions listed. Relevant questions to the student may often be helpful in making differential diagnosis within this category of conditions ⁽³⁾. It involves: A. Anomalies of eruption and development By the age of 13 years most of the students should have a full set of permanent teeth except for the third molars. 1. Missing permanent teeth due to extraction or trauma (Code: E): All missing permanent teeth were registered, even if a bridge or partial denture had replaced them. The presence of spacing, the contour of the underlying alveolar ridge, the caries-experience of present teeth and pertinent questions to the student usually allow a correct assessment of missing teeth due to extraction or trauma ⁽³⁾. 2. Unerupted teeth (Code: X): All unerupted permanent teeth, other than third molars, were registered. Considering the students’ age canines and second molars might have not yet erupted and were recorded. Other missing teeth were distinguished from congenitally absent teeth and missing due to extraction and trauma ⁽⁴⁾. 3. Partially erupted teeth (Code: P): A partially erupted tooth was considered as a tooth that had not reached the occlusal level. 4. Retained deciduous teeth (Code: D): Any present deciduous teeth were recorded, whether the successor permanent tooth had erupted or not. 5. Congenitally absent teeth: Considering the student’s chronological and dental ages, those teeth that were assessed to be congenitally absent were entered under remarks. When the student gave a history of no previous extraction(s), and the contour of the underlying alveolar ridge did not indicate an impacted tooth, it was assumed that the tooth was congenitally absent ⁽³⁾. It was possible that missing teeth were mistaken for congenitally absent teeth in the absence of radiographic examination and vice versa, but only one of these items was registered. In case of doubt the entry was made under ‘missing tooth’ and under ‘remarks’ ⁽⁴⁾. B. Anomalies of alignment 1. Rotated teeth Fully erupted teeth that were rotated more than 15º were registered under ‘mesial’ or ‘distal’ rotation. The degree of rotation was measured with the registration instrument ⁽⁴⁾. 2. Displaced teeth Any tooth displaced bodily from the ideal arch line by more than 1mm was registered under ‘buccal’ or ‘palatal’ displacement ⁽¹⁰⁾. RESULTS Anomalies in the dentition 1. Missing permanent teeth due to extraction or trauma: Of the sample, 6.8% had one or more missing permanent teeth due to extraction or trauma. The most common extracted tooth was the mandibular first molar (2.9%), then the maxillary first molar (1.0%) (Table 1). Table 1: Distribution of missing permanent teeth due to extraction or trauma of the whole sample. Side Right Left Tooth No. ◄7 ◄6 ◄5 ◄4 ◄3 ◄2 ◄1 1► 2► 3► 4► 5► 6► 7► Maxillary n 0 11 0 0 0 0 0 1 0 0 0 0 90 1 % 0.0 1.1 0.0 0.0 0.0 0.0 0.0 0.1 0.0 0.0 0.0 0.0 0.9 0.1 Mandibular n 0 29 1 0 0 0 0 0 0 0 1 2 27 1 % 0.0 3.0 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.1 0.2 2.8 0.1 J Bagh College Dentistry Vol. 25(2), June 2013 Dental anomalies associated Orthodontics, Pedodontics and Preventive Dentistry175 2. Partially erupted teeth The most common partially erupted tooth was the maxillary canine (4.2%), then the maxillary second molars (2.3%), mandibular second molars (1.9%),and then maxillary second premolars (1.6%) (Table 2). Table 2: Distribution of partially erupted teeth of the whole sample. Side Right Left Tooth No. ◄7 ◄6 ◄5 ◄4 ◄3 ◄2 ◄1 1► 2► 3► 4► 5► 6► 7► Maxillary n 28 0 16 9 31 1 0 1 0 51 11 14 0 17 % 2.9 0.0 1.7 0.9 3.2 0.1 0.0 0.1 0.0 5.3 1.1 1.5 0.0 1.8 Mandibular n 15 0 5 7 8 1 0 1 0 4 6 10 0 21 % 1.6 0.0 0.5 0.7 0.8 0.1 0.0 0.1 0.0 0.4 0.6 1.0 0.0 2.2 3. Unerupted teeth The most common unerupted tooth was the maxillary second molars (10%), then the mandibular second molars (4.7%), maxillary canine (1.4%) ,and mandibular second premolars (1.2%) (Table 3). Table 3: Distribution of still unerupted teeth of the whole sample. Side Right Left Tooth No. ◄7 ◄6 ◄5 ◄4 ◄3 ◄2 ◄1 1► 2► 3► 4► 5► 6► 7► Maxillary n 96 0 8 0 15 0 0 0 0 12 0 4 1 95 % 10.1 0.0 0.8 0.0 1.6 0.0 0.0 0.0 0.0 1.2 0.0 0.4 0.1 10.0 Mandibular n 51 0 12 1 1 0 0 0 0 1 2 11 1 39 % 5.3 0.0 1.3 0.1 0.1 0.0 0.0 0.0 0.0 0.0 0.2 1.1 0.1 4.1 4. Retained deciduous teeth: Of the sample 27.3% had retained deciduous teeth. The most common retained deciduous tooth was the maxillary canine (6.8%), then the maxillary second molars (5.4%), mandibular second molars (2.4%), and then both maxillary first molars (0.9%) with mandibular canines (0.9%) (Table 4). Table 4: Distribution of retained deciduous teeth of the whole sample. Side Right Left Tooth No. ◄E ◄D ◄C ◄B ◄A A► B► C► D► E► Maxillary n 52 11 68 0 0 0 0 62 7 50 % 5.5 1.1 7.1 0.0 0.0 0.0 0.0 6.5 0.7 5.3 Mandibular n 30 8 6 0 0 0 1 10 3 17 % 3.1 0.8 0.6 0.0 0.0 0.0 0.1 1.0 0.3 1.8 5. Congenitally absent teeth: Hypodontia as judged clinically was found in 2.1% of the sample affecting one or more permanent teeth. The most common congenitally missing tooth was the maxillary lateral incisor (0.9%), mandibular second premolars (0.4%), and then maxillary second premolar (0.2%) (Table 5). 6. Rotated teeth: Of the sample, 26.5 % were found to have one or more rotated teeth. The most common rotated tooth was the mandibular second premolars (5.3%), then mandibular canine (5.1%), maxillary canine (4.5%), and mandibular first premolars (2.8%) but the least rotated tooth was maxillary second premolars (0.5%) (Table 6). J Bagh College Dentistry Vol. 25(2), June 2013 Dental anomalies associated Orthodontics, Pedodontics and Preventive Dentistry176 Table 5: Distribution of congenitally missing teeth of the whole sample Side Right Left Tooth No. ◄5 ◄4 ◄3 ◄2 ◄1 1► 2► 3► 4► 5► Maxillary n 1 1 0 8 0 0 11 0 2 3 % 0.1 0.1 0.0 0.8 0.0 0.0 1.1 0.0 0.2 0.3 Mandibular n 5 1 0 0 0 1 1 0 0 3 % 0.5 0.1 0.0 0.0 0.0 0.1 0.1 0.0 0.0 0.3 * These numbers are of only the teeth that were surely congenitally missing by clinical examination and history. Table 6: Distribution of rotated teeth of the whole sample. Side Right Left Tooth No. ◄5 ◄4 ◄3 ◄2 ◄1 1► 2► 3► 4► 5► Maxillary n 4 9 48 21 19 20 23 38 8 6 % 0.4 0.9 5.0 2.2 2.0 2.1 2.4 4.0 0.8 0.6 Mandibular n 47 30 48 13 10 9 21 51 25 55 % 4.9 3.1 5.0 1.4 1.0 0.9 2.2 5.3 2.6 5.7 7. Displaced teeth: Of the sample, 28.6% were found to have one or more displaced teeth. The most common displaced tooth was the maxillary lateral incisor (9.8%) then the maxillary canine (7.5%) , mandibular canine (3.7%), and mandibular laterals (2.3%), while the least commonly displaced teeth were the maxillary first premolars (0.3%), maxillary second premolars (0.6%), maxillary central incisors (0.9%) and both the mandibular first premolar and the mandibular central incisor (1.1%) (Table 7). Table 7: Distribution of buccally and palatally displaced teeth of the whole sample. Direction of displacement Side Right Left Tooth No. ◄5 ◄4 ◄3 ◄2 ◄1 1► 2► 3► 4► 5► Buccal Maxillary n 0 2 65 49 7 4 46 62 2 1 % 0.0 0.2 6.8 5.1 0.7 0.4 4.8 6.5 0.2 0.1 Mandibular n 8 7 30 10 9 11 3 25 9 7 % 0.8 0.7 3.1 1.0 0.9 1.1 0.3 2.6 0.9 0.7 Palatal Maxillary n 6 0 7 45 5 2 47 9 3 6 % 0.6 0.0 0.7 4.7 0.5 0.2 4.9 0.9 0.3 0.6 Mandibular n 12 0 6 20 1 2 12 9 5 14 % 1.2 0.0 0.6 2.1 0.1 0.2 1.2 0.9 0.5 1.5 Total Maxillary n 6 2 72 94 12 6 93 71 5 7 % 0.6 0.2 7.6 9.9 1.2 0.6 9.8 7.4 0.5 0.7 Mandibular n 20 7 36 30 10 13 15 34 14 21 % 2.1 0.7 3.8 3.1 1.0 1.3 1.6 3.6 1.5 2.2 J Bagh College Dentistry Vol. 25(2), June 2013 Dental anomalies associated Orthodontics, Pedodontics and Preventive Dentistry177 DISCUSSION Anomalies in the dentition: A. Anomalies of eruption and development: In the present study, 6.8% of the sample had one or more missing teeth due to extraction or trauma. This was near to 6% of ⁽¹²⁾, 6% of the 13 year old sample of ⁽¹³⁾ and 7.3% of ⁽⁹⁾, while it was much lower than 9.8% of ⁽¹⁴⁾ and 10% of the 13 year old sample of ⁽⁷⁾. The most common extracted tooth was the mandibular first molar (2.9%), then the maxillary first molar (1.0%). This is in near to the findings of ⁽¹⁵,¹⁶,⁹⁾. Cons et al ⁽¹⁷⁾ found that 3.22% of their 15-18 year old sample had one or more retained deciduous teeth mostly involving single teeth. This was much lower than that found in this study (27.3%) because of the older age of the former study. The most common retained deciduous tooth was the maxillary canine and then the deciduous second molars. This may be because of their late eruption time and the high congenital absence of the second premolars as found by ⁽¹⁸⁾ which was 2% for the mandibular and 1.1% for the maxillary. Hypodontia was found in 2.1% of the present sample and it was low when compared to the 5% found by⁽¹⁹⁾ among orthodontic patients or the 3.36% found by ⁽¹⁸⁾among the Medical Technology Institute students, while near to the findings of ⁽⁹⁾. The most common congenitally missing tooth was the maxillary lateral incisor, then the mandibular second premolar, maxillary second premolar. This finding disagrees with those of ⁽²⁰ ²¹ ²² ²³ ²⁴ ²⁵²⁶⁶ ¹⁸⁾ who found the mandibular second premolar to be the most prevalent followed the maxillary lateral incisor. On the other hand, our finding comes in coincidence with that of ⁽²⁷ ²⁸ ²⁹ ³⁰ ³¹ ³² ¹⁹ ⁹⁾. Anomalies of alignment: A. Rotated teeth: In this study, 26.5 % had one or more rotated teeth (>15˚). This prevalence was lower than that found by ⁽¹⁰ ⁷ ¹³ ³³ ³⁴⁾, while near to⁽⁹⁾. It is difficult to compare our result with those of many other previous studies because of differences in the definition and criteria used. The most common rotated tooth were the mandibular second premolars then mandibular canine, and maxillary canine which were in reverse to the readings of ⁽⁹⁾ that showed mandibular canine as the most common rotated tooth then the mandibular second premolar. B. Displaced teeth: In this study 28.6% had one or more displaced teeth (>1mm). This prevalence was remarkably more than the 14.5% and 13.5% found by ⁽⁷ ¹³⁾ in their 13 year old samples. This finding is also higher than that found by ⁽¹⁰⁾ and this may be explained by differences in definition and criteria used as ⁽¹⁰⁾ recorded only displacements more than 1.5mm.The findings near to that of ⁽⁹⁾ that had the same criteria of the sample. The most common buccally displaced tooth was the maxillary canine (6.8% on the right and 6.5% on the left sides) that near to the findings of ⁽⁹⁾ while it was lower than the finding of ⁽³⁵⁾ who examined 2851 Iraqi 13-14 year olds to find that 8.3% of them had one or two buccally malposed canines. The most common palatally displaced tooth was the maxillary lateral incisor (4.7% on the right and 4.9% on the left sides). This is due to the developmental position of the maxillary lateral incisor germ palatal to the roots of the central incisors ⁽³⁶⁾. The results were also near to ⁽⁹⁾. The conclusions from this study were: 1. 6.8% of the sample had one or more missing permanent teeth due to extraction or trauma. 2. Hypodontia was found in 2.1% of the sample affecting one or more permanent teeth. 3. From the whole sample 26.5 % were found to have one or more rotated teeth. The most common rotated tooth was the mandibular second premolars, while the displaced teeth were in 28.6% that have one or more displaced teeth. The most common displaced tooth was the maxillary lateral incisor 4. At the age of 13 both males and females show large range of dental anomalies that are better to be controlled. REFERENCES 1. Graber TM. Orthodontics: principles and practice. 3rd ed. Philadelphia: WB Saunders Co.; 1988 2. Salonen L, Mohlin B, Götzlinger B, Helldén L. Need and demand for orthodontic treatment in an adult Swedish population. Eur J Orthod 1992; 14(5): 359- 68. 3. Baume LJ, Horowitz HS, Summers CJ, Backer Dirks O, Carlos JP, Cohen LK. A method for measuring occlusal traits developed by the FDI commission on classification and statistics for oral conditions. Int Dent J 1973; 23: 530-7. 4. Björk A, Krebs ÅA, Solow B. A method for epidemiological registration of malocclusion. Acta Odontol Scand 1964; 22: 27-41. 5. Ministry of Health. Health status in Iraq. The Directorate of planning and Administrable Development. Ministry of health, Baghdad; 1998. 6. Kinaan BK. Overjet and overbite distribution and correlation: a comparative epidemiological English- Iraqi study. Brit J Orthod 1986; 13: 79-86. J Bagh College Dentistry Vol. 25(2), June 2013 Dental anomalies associated Orthodontics, Pedodontics and Preventive Dentistry178 7. Abdulla NM. Occlusal features and perception: a sample of 13-17 years old adolescents. Master Thesis, College of Dentistry, University of Baghdad, 1996. 8. Alazawi LA. Oral health status and treatment needs among Iraqi five years old kindergarten children and fifteen years old students: a national survey. Ph.D. Thesis, College of Dentistry, University of Baghdad, 2000. 9. Al-Huwaizi AF. Occlusal features, perception of occlusion, orthodontic treatment need and demand among 13 year old Iraqi students. Ph.D. Thesis, College of Dentistry, University of Baghdad, 2002. 10. Van Kirk LE Jr, Pennell EH. Assessment of malocclusion in population groups. Am J Orthod 1959; 45(10): 752-8. 11. World Health Organization. Oral health surveys: basic methods. 4th ed. Geneva: WHO, the Organization; 1997. 12. Garner LD, Butt MH. Malocclusion in Black Americans and Nyeri Kenyans. An epidemiologic study. Angle Orthod 1985; 55(2): 139-46. 13. Batayine FAM. Occlusal features and perception of occlusion of Jordanian adolescents: a comparative study with an Iraqi sample. Master Thesis, College of Dentistry, University of Baghdad, 1997. 14. Schaschula RG, Cooper MH, Wright MC, Agus HM, Un PSH. Oral health of adolescent and adult Australian aborigines. Community Dent Oral Epidemiol 1980; 8: 370-4. 15. Massler M, Frankel JM. Prevalence of malocclusion in children aged 14 to 18 years. Am J Orthod 1951; 37: 751-68. 16. Al-Makadsi FB, Al-Sahar WF. A study of posterior tooth loss in 15 year old Iraqi students. Iraq Dent J 1985; 12: 155-164. 17. Cons NC, Mruthyunjaya YC, Pollard ST. Distribution of occlusal traits in a sample of 1337 children aged 15- 18 residing in upstate New York. Int Dent J 1978; 28(2): 154-64. 18. Al-Mulla AA, Mahdi TS, Hamid NH. Incidence of hypodontia of permanent teeth. Iraq J Medical Technology 1990; 7: 69-80. 19. Kinaan BK. Characteristics and management of hypodontia in Iraqi orthodontic patients. Iraqi Dent J 1985; 12: 133-143. 20. Dolder E. Deficient dentition. Dent Rec 1937; 57: 142-3. 21. Byrd ED. Incidence of supernumerary and congenitally missing teeth. J Dent Child 1943; 10: 84- 6. 22. Brown RV. The pattern and frequency of congenital absence of teeth. Iowa State Dent J 1957; 43: 60-1. 23. Gysel G. Anodontie, oligodontie, hypodontie. Orthodontie francnise 1957; 32: 403-13. 24. Rose JS. A survey of congenitally missing teeth, excluding third molars in 6000 orthodontic patients. Dent Pract Dent Res 1966; 17: 107-14. 25. Monteil M. Contributional, etude et autraitment del agenesis dela dent permenente. The 3 eme cycle Sci Odont. Paris VII; 1968. 26. Al-Mulla AAH. A study of hypodontia of permanent teeth. Doctoral Thesis, College of Dentistry, University of Paris VII; 1986. 27. Werther A, Rothenberg F. Anodontia. Am J Orthod 1939; 25: 61-81. 28. Reitan K. Clige et anodontie. Den Norske T Mars 1953; 65-77. 29. Rosenzweig KA, Garbaski D. Numerical aberrations in the permanent teeth of grade school children in Jerusalem. Am J Phys Anthropol 1965; 23: 277-83. 30. Castaldi CR, Bodnarchuk A, MacRae PD, Zacherl WA. Incidence of congenital anomalies in permanent teeth of a group of Canadian children aged 6-9 years. J Can Dent Assoc 1966; 32: 154-9. 31. Muller TP, Hill IN, Patersen AC, Blayney JR. A summary of congenitally missing permanent teeth. J Am Dent Assoc 1970; 81: 101-7. 32. Baume BJ, Cohen MM. Studies of agenesis in the permanent dentition. Am J Phys Anthropol 1971; 35: 125-8. 33. Helm S. Malocclusion in Danish children with adolescent dentition: an epidemiologic study. Am J Orthod 1968; 54: 356-66. 34. Hoffding J, Kisling E. Premature loss of primary teeth: Part I: Its over all effect on occlusion and space in the permanent dentition. ASDC J Dent Child;1978. 35. Ghaib NH. Buccally malposed canines: a survey of school children aged 13-14 years. Master Thesis, College of Dentistry, University of Baghdad, 1992. 36. Walther DP. Walther’s Orthodontic notes. 1st ed. Bristol: Wright PSG; 1960.