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Prevalence of malocclusion among Latino adolescents
SHORT COMMUNICATION
Prevalence of malocclusion among Latino adolescents Rebeka G. Silva, DMD,a and David S. Kang, DDSb San Francisco and Los Angeles, Calif Although numerous studies have documented malocclusion in various ethnic groups in the United States, the prevalence of malocclusion in the Latino population is not well known. The Latino population may be the largest minority group in the United States by the year 2004. This study analyzes the occlusion of 507 Latino adolescents between the ages of 12 and 18 years. More than 93% of the subjects demonstrated some form of malocclusion. The distribution of malocclusion patterns is presented and contrasted with data published for other ethnic groups. Information about the prevalence and types of malocclusion in the Latino population should be of interest to general dental practitioners and specialists. (Am J Orthod Dentofacial Orthop 2001;119:313-5)
O
nly 1 study of the incidence of malocclusion in the Latino population has been published in the literature.1 The purpose of our study was to document the incidence of malocclusion in Latino adolescents. Adolescents have generally not completed growth but are often referred for orthodontic evaluation and treatment. According to 1998 estimates released by the US Census Bureau, the Latino population is the second largest minority population in the United States. It is estimated that by the year 2004, the Latino population will become the largest minority group in the United States, overtaking the non-Latino black population. Sometime after the year 2020, the Latino population may surpass the white population as the majority group in the nation. Information about the incidence and types of malocclusion in the Latino population should be of interest to dental professionals, including general practitioners, specialists, and public health workers.
MATERIAL AND METHODS
A total of 507 Latino individuals were prospectively examined between 1995 and 1999 in California. Study subjects were selected consecutively for inclusion in the study because they were seen in the dental office for treatment or because they came to the Su Salud Health aChief,
Dental Service, VA Medical Center, and Assistant Clinical Professor, Department of Oral and Maxillofacial Surgery, University of California–San Francisco Medical Center. bPrivate practice, Los Angeles, Calif. Reprint requests to: Rebeka G. Silva, DMD, Chief, Dental Service, VA Medical Center, 4150 Clement St, San Francisco, CA 94121; e-mail, rebeka.silva@ med.va.gov. Submitted, May 2000; revised and accepted, July 2000. Copyright © 2001 by the American Association of Orthodontists. 0889-5406/2001/$35.00 + 0 8/1/110985 doi:10.1067/mod.2001.110985
Fair for dental screening. All male and female patients who met the following inclusion criteria were included in the sample: (1) age 12 to 18 years, (2) Latino ethnic background, (3) secondary dentition present with no remaining deciduous teeth, (4) no multiple missing teeth, and (5) no previous history of orthodontic treatment. Each examination took place while the subject was sitting in a dental chair. A qualitative analysis with Angle’s classification was used to describe the anteroposterior relationship of the maxillary and mandibular first molars during maximum intercuspation.2 Findings were classified in the following categories: Class I normal occlusion, Class I malocclusion, Class II Division 1, Class II Division 2, and Class III malocclusion. Patients with an occlusal pattern that deviated from the Class I relationship as described by Angle (including crowding, spacing, and rotations) were categorized as Class I malocclusion. Thus, the Class I normal category was limited to patients with occlusions that were ideal or near ideal. Patients with a different Angle classification of occlusion on each side were categorized into a single class based on the predominant pattern of occlusion and/or canine relationship. RESULTS
The results of the study are graphically shown in Fig 1. Most of the patients described themselves as Mexican or Mexican-American. All subjects were either from the Los Angeles metropolitan area or from the San Joaquin valley. Class I malocclusion was found in 319 subjects, which represented 62.9% of the 507 individuals examined. In contrast, only 33 subjects (6.5%) had Class I normal occlusion. Class II malocclusion was diagnosed in 109 individuals (21.5%); 94.5% of those patients 313
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Fig 1. Distribution of types of occlusion in Latino adolescents. Table I. Prevalence
Author Horowitz8 Garner and Butt9 Lew et al10 Present study
of malocclusion among different ethnic groups
Ethnicity
Sample size (n)
Class I normal (%)
Class I malocclusion (%)
Class II malocclusion (%)
Class III malocclusion (%)
White Black Chinese Latino
718 445 1050 507
6.8 31.3 7.1 6.5
65.2 44.0 58.8 62.9
22.5 16.0 21.5 21.5
5.5 8.7 12.6 9.1
were Class II Division 1. The Class III malocclusion group consisted of 46 individuals (9.1%). DISCUSSION
Although numerous studies have been published that describe the prevalence and types of malocclusion, it is difficult to compare and contrast these findings, in part because of the varying methods and indices used to assess and record occlusal relationships.3-7 Other variables (including age differences of the study populations, examiner subjectivity, specific objectives, and differing sample sizes) further complicate efforts to understand and appreciate the differences recorded in patterns of malocclusion between ethnic groups. Although Angle’s classification is limited in that it does not incorporate vertical and transverse abnormalities, it is a universally accepted system that is reliable and repeatable and that minimizes examiner subjectivity. The incidence of malocclusion in white Americans was studied by the US Public Health Service in the third National Health and Nutrition Examination Survey (NHANES III) between 1988 and 1991.1 It was estimated that 52.2% of 8- to 50-year-old subjects had Class I occlusion, as determined by an ideal 1- to 2-mm
overjet. This Class I occlusion figure includes individuals with incisor crowding and dental malalignment and thus does not imply ideal Class I occlusion. Class II malocclusion (mild to severe) was found in 42.4% of subjects, and Class III malocclusion (mild to severe) was found in less than 5% of subjects. When data from the present study are compared with the NHANES III data for white subjects, Latino adolescents demonstrate a higher combined rate of Class I occlusion and Class I malocclusion of 69.4%. The incidence of Class II malocclusions is lower at 21.5%, and the incidence of Class III malocclusion is higher at 9.1%. Of particular note is the incidence of Class III malocclusion. This finding is consistent with the NHANES III survey, which also reported a high incidence (8.3%) of Class III overjet relationship in Mexican-Americans.1 When Latino subjects in this study are compared with white subjects,8 black subjects,9 and Chinese subjects,10 specific differences are evident. These differences are summarized in Table I. Latino subjects had the lowest incidence of Class I normal occlusion (6.5%) compared with 6.8% for white subjects, 7.1% for Chinese subjects, and 31.3% for black subjects. Latino subjects had slightly lower rates of Class I mal-
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occlusion than white subjects, but this pattern was more predominant when compared with Chinese and black subjects (58.8% and 44.0%, respectively). The recorded incidence for Class II malocclusions was the same as that found for Chinese subjects (21.5%) and similar to that found for white subjects (22.5%) but higher than that reported for black subjects (16.0%). A study of malocclusion in Senegal11 indicated a relatively lower incidence of Class II malocclusion among African subjects compared with other ethnic groups. The incidence of Class III relationship was highest in the Chinese study (12.6%), followed by the Latino subjects in the present study (9.1%), black subjects (8.7%), and white subjects (5.5%). The prevalence of Class III molar relationship might be expected to be greater in an older study population when growth of the mandible has reached its stable end-stage.12 The Mexican-American subjects included in this study might not be representative of the Latino population at large. Hispanic or Latino populations from the Caribbean, South America, and Central America south of Mexico may demonstrate different patterns of malocclusion. CONCLUSION
A sample of 507 Latino adolescents in California between the ages of 12 and 18 years was examined with Angle’s classification system to determine malocclusion prevalence. Only 6.5% of the sample demonstrated normal Class I occlusion, leaving more than 93% of the sample subjects with some type of malocclusion. Although this study did not assess the severity of the malocclusions that were encountered, it appears that the need for orthodontic referral in this population group is high, as is the potential for orthodontic treat-
ment. The prevalence of malocclusion in the rapidly growing Latino population deserves attention from dental health care professionals. Further investigation in this area appears warranted, including examination of Latino groups of different ethnic backgrounds. We thank Mr Henry Park and Carmen Basurto, DDS, for technical assistance. REFERENCES 1. Proffitt WR, Fields HW, Moray LJ. Prevalence of malocclusion and orthodontic treatment need in the United States: estimates from the NHANES III survey. Int J Adult Orthod Orthogn Surg 1998;13:97-106. 2. Angle EH. Classification of malocclusion. Dent Cosmos 1899; 41:248-64. 3. Grainger RM. Orthodontic treatment priority index. Washington: US Public Health Service, 1968. Publication No. 1000-Series 2, No. 25. Washington, DC: National Center for Health Statistics; 1967. 4. Salzmann JA. Handicapping malocclusion assessment to establish treatment priority. Am J Orthod 1968;54:749-65. 5. Baume LJ. Uniform methods for the epidemiologic assessment of malocclusion: results obtained with the World Health Organization standard methods (1962 and 1971) in South Pacific populations. Am J Orthod 1974;66:251-72. 6. Bezronkow V, Freer T, Helm S. Basic method for recording occlusal traits. Bull World Health Organ 1979;57:955-61. 7. Tang EL, Wei SH. Recording and measuring malocclusion: a review of the literature. Am J Orthod Dentofacial Orthop 1993;103:344-51. 8. Horowitz HS. A study of occlusal relations in 10 to 12 year old Caucasian and Negro children: summary report. Int Dent J 1970;20:593-605. 9. Garner LD, Butt MH. Malocclusion in black Americans and Nyeri Kenyans: an epidemiologic study. Angle Orthod 1985;55:139-46. 10. Lew KK, Foong WC, Loh E. Malocclusion prevalence in an ethnic Chinese population. Aust Dent J 1993;38:442-9. 11. Diagne F, Ba I, Ba-Diop K, et al. Prevalence of malocclusion in Senegal. Community Dent Oral Epidemiol 1993;21:325-6. 12. Proffitt WR, Fields HW. Contemporary orthodontics. 2nd edition. St Louis (MO): Mosby; 1993
Prevalence of malocclusion among Latino adolescents Rebeka G. Silva, DMD,a and David S. Kang, DDSb San Francisco and Los Angeles, Calif Although numerous studies have documented malocclusion in various ethnic groups in the United States, the prevalence of malocclusion in the Latino population is not well known. The Latino population may be the largest minority group in the United States by the year 2004. This study analyzes the occlusion of 507 Latino adolescents between the ages of 12 and 18 years. More than 93% of the subjects demonstrated some form of malocclusion. The distribution of malocclusion patterns is presented and contrasted with data published for other ethnic groups. Information about the prevalence and types of malocclusion in the Latino population should be of interest to general dental practitioners and specialists. (Am J Orthod Dentofacial Orthop 2001;119:313-5)
O
nly 1 study of the incidence of malocclusion in the Latino population has been published in the literature.1 The purpose of our study was to document the incidence of malocclusion in Latino adolescents. Adolescents have generally not completed growth but are often referred for orthodontic evaluation and treatment. According to 1998 estimates released by the US Census Bureau, the Latino population is the second largest minority population in the United States. It is estimated that by the year 2004, the Latino population will become the largest minority group in the United States, overtaking the non-Latino black population. Sometime after the year 2020, the Latino population may surpass the white population as the majority group in the nation. Information about the incidence and types of malocclusion in the Latino population should be of interest to dental professionals, including general practitioners, specialists, and public health workers.
MATERIAL AND METHODS
A total of 507 Latino individuals were prospectively examined between 1995 and 1999 in California. Study subjects were selected consecutively for inclusion in the study because they were seen in the dental office for treatment or because they came to the Su Salud Health aChief,
Dental Service, VA Medical Center, and Assistant Clinical Professor, Department of Oral and Maxillofacial Surgery, University of California–San Francisco Medical Center. bPrivate practice, Los Angeles, Calif. Reprint requests to: Rebeka G. Silva, DMD, Chief, Dental Service, VA Medical Center, 4150 Clement St, San Francisco, CA 94121; e-mail, rebeka.silva@ med.va.gov. Submitted, May 2000; revised and accepted, July 2000. Copyright © 2001 by the American Association of Orthodontists. 0889-5406/2001/$35.00 + 0 8/1/110985 doi:10.1067/mod.2001.110985
Fair for dental screening. All male and female patients who met the following inclusion criteria were included in the sample: (1) age 12 to 18 years, (2) Latino ethnic background, (3) secondary dentition present with no remaining deciduous teeth, (4) no multiple missing teeth, and (5) no previous history of orthodontic treatment. Each examination took place while the subject was sitting in a dental chair. A qualitative analysis with Angle’s classification was used to describe the anteroposterior relationship of the maxillary and mandibular first molars during maximum intercuspation.2 Findings were classified in the following categories: Class I normal occlusion, Class I malocclusion, Class II Division 1, Class II Division 2, and Class III malocclusion. Patients with an occlusal pattern that deviated from the Class I relationship as described by Angle (including crowding, spacing, and rotations) were categorized as Class I malocclusion. Thus, the Class I normal category was limited to patients with occlusions that were ideal or near ideal. Patients with a different Angle classification of occlusion on each side were categorized into a single class based on the predominant pattern of occlusion and/or canine relationship. RESULTS
The results of the study are graphically shown in Fig 1. Most of the patients described themselves as Mexican or Mexican-American. All subjects were either from the Los Angeles metropolitan area or from the San Joaquin valley. Class I malocclusion was found in 319 subjects, which represented 62.9% of the 507 individuals examined. In contrast, only 33 subjects (6.5%) had Class I normal occlusion. Class II malocclusion was diagnosed in 109 individuals (21.5%); 94.5% of those patients 313
314 Silva and Kang
American Journal of Orthodontics and Dentofacial Orthopedics March 2001
Fig 1. Distribution of types of occlusion in Latino adolescents. Table I. Prevalence
Author Horowitz8 Garner and Butt9 Lew et al10 Present study
of malocclusion among different ethnic groups
Ethnicity
Sample size (n)
Class I normal (%)
Class I malocclusion (%)
Class II malocclusion (%)
Class III malocclusion (%)
White Black Chinese Latino
718 445 1050 507
6.8 31.3 7.1 6.5
65.2 44.0 58.8 62.9
22.5 16.0 21.5 21.5
5.5 8.7 12.6 9.1
were Class II Division 1. The Class III malocclusion group consisted of 46 individuals (9.1%). DISCUSSION
Although numerous studies have been published that describe the prevalence and types of malocclusion, it is difficult to compare and contrast these findings, in part because of the varying methods and indices used to assess and record occlusal relationships.3-7 Other variables (including age differences of the study populations, examiner subjectivity, specific objectives, and differing sample sizes) further complicate efforts to understand and appreciate the differences recorded in patterns of malocclusion between ethnic groups. Although Angle’s classification is limited in that it does not incorporate vertical and transverse abnormalities, it is a universally accepted system that is reliable and repeatable and that minimizes examiner subjectivity. The incidence of malocclusion in white Americans was studied by the US Public Health Service in the third National Health and Nutrition Examination Survey (NHANES III) between 1988 and 1991.1 It was estimated that 52.2% of 8- to 50-year-old subjects had Class I occlusion, as determined by an ideal 1- to 2-mm
overjet. This Class I occlusion figure includes individuals with incisor crowding and dental malalignment and thus does not imply ideal Class I occlusion. Class II malocclusion (mild to severe) was found in 42.4% of subjects, and Class III malocclusion (mild to severe) was found in less than 5% of subjects. When data from the present study are compared with the NHANES III data for white subjects, Latino adolescents demonstrate a higher combined rate of Class I occlusion and Class I malocclusion of 69.4%. The incidence of Class II malocclusions is lower at 21.5%, and the incidence of Class III malocclusion is higher at 9.1%. Of particular note is the incidence of Class III malocclusion. This finding is consistent with the NHANES III survey, which also reported a high incidence (8.3%) of Class III overjet relationship in Mexican-Americans.1 When Latino subjects in this study are compared with white subjects,8 black subjects,9 and Chinese subjects,10 specific differences are evident. These differences are summarized in Table I. Latino subjects had the lowest incidence of Class I normal occlusion (6.5%) compared with 6.8% for white subjects, 7.1% for Chinese subjects, and 31.3% for black subjects. Latino subjects had slightly lower rates of Class I mal-
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American Journal of Orthodontics and Dentofacial Orthopedics Volume 119, Number 3
occlusion than white subjects, but this pattern was more predominant when compared with Chinese and black subjects (58.8% and 44.0%, respectively). The recorded incidence for Class II malocclusions was the same as that found for Chinese subjects (21.5%) and similar to that found for white subjects (22.5%) but higher than that reported for black subjects (16.0%). A study of malocclusion in Senegal11 indicated a relatively lower incidence of Class II malocclusion among African subjects compared with other ethnic groups. The incidence of Class III relationship was highest in the Chinese study (12.6%), followed by the Latino subjects in the present study (9.1%), black subjects (8.7%), and white subjects (5.5%). The prevalence of Class III molar relationship might be expected to be greater in an older study population when growth of the mandible has reached its stable end-stage.12 The Mexican-American subjects included in this study might not be representative of the Latino population at large. Hispanic or Latino populations from the Caribbean, South America, and Central America south of Mexico may demonstrate different patterns of malocclusion. CONCLUSION
A sample of 507 Latino adolescents in California between the ages of 12 and 18 years was examined with Angle’s classification system to determine malocclusion prevalence. Only 6.5% of the sample demonstrated normal Class I occlusion, leaving more than 93% of the sample subjects with some type of malocclusion. Although this study did not assess the severity of the malocclusions that were encountered, it appears that the need for orthodontic referral in this population group is high, as is the potential for orthodontic treat-
ment. The prevalence of malocclusion in the rapidly growing Latino population deserves attention from dental health care professionals. Further investigation in this area appears warranted, including examination of Latino groups of different ethnic backgrounds. We thank Mr Henry Park and Carmen Basurto, DDS, for technical assistance. REFERENCES 1. Proffitt WR, Fields HW, Moray LJ. Prevalence of malocclusion and orthodontic treatment need in the United States: estimates from the NHANES III survey. Int J Adult Orthod Orthogn Surg 1998;13:97-106. 2. Angle EH. Classification of malocclusion. Dent Cosmos 1899; 41:248-64. 3. Grainger RM. Orthodontic treatment priority index. Washington: US Public Health Service, 1968. Publication No. 1000-Series 2, No. 25. Washington, DC: National Center for Health Statistics; 1967. 4. Salzmann JA. Handicapping malocclusion assessment to establish treatment priority. Am J Orthod 1968;54:749-65. 5. Baume LJ. Uniform methods for the epidemiologic assessment of malocclusion: results obtained with the World Health Organization standard methods (1962 and 1971) in South Pacific populations. Am J Orthod 1974;66:251-72. 6. Bezronkow V, Freer T, Helm S. Basic method for recording occlusal traits. Bull World Health Organ 1979;57:955-61. 7. Tang EL, Wei SH. Recording and measuring malocclusion: a review of the literature. Am J Orthod Dentofacial Orthop 1993;103:344-51. 8. Horowitz HS. A study of occlusal relations in 10 to 12 year old Caucasian and Negro children: summary report. Int Dent J 1970;20:593-605. 9. Garner LD, Butt MH. Malocclusion in black Americans and Nyeri Kenyans: an epidemiologic study. Angle Orthod 1985;55:139-46. 10. Lew KK, Foong WC, Loh E. Malocclusion prevalence in an ethnic Chinese population. Aust Dent J 1993;38:442-9. 11. Diagne F, Ba I, Ba-Diop K, et al. Prevalence of malocclusion in Senegal. Community Dent Oral Epidemiol 1993;21:325-6. 12. Proffitt WR, Fields HW. Contemporary orthodontics. 2nd edition. St Louis (MO): Mosby; 1993