Differences in dentofacial characteristics of Class I malocclusion between Saudi and Japanese adult females

Samurai in Japan: Class System-Related Morphological Differences in Maxillofacial Regions in the Edo Period

Previous studies have reported that compared to commoners in Japan’s Edo period, samurai had long heads, more dental irregularities, and slightly worn teeth. However, these studies did not measure the mandible or only measured length. Angular analysis is essential to evaluate the maxillofacial morphology, but there are no comparative studies of samurai and commoners. This study explored the differences in maxillofacial morphology between samurai and commoners in the Edo period. Thirty male skeletons (samurai) and thirty-eight male skeletons (commoners) were used as materials from the National Museum of Nature and Science. The selected specimens were adults aged between 20 and 59 years without serious skeletal damage and with stable occlusion of the molars. We used three-dimensional scanning to measure the specimens’ skeletal, alveolar, and facial widths. The mandibular plane angle and the gonial angle were significantly larger in the samurai than in the commoners. The ratio of the intermandibular first molars, interzygomatic arch, and mandibular width was significantly shorter in the samurai than in the commoners. The samurai had a high angle tendency and smaller mandibular width than the commoners, reflecting the class system.

A Comparison of Craniofacial Characteristics between Two Different Adult Populations with Class II Malocclusion-A Cross-Sectional Retrospective Study

Simple Summary

One of the most common orthodontic problems, Class II malocclusion, may lead to an increased risk of dentoalveolar trauma, psychosocial issues, and a possible compromised quality of life. Oftentimes clinicians use normative standard values to which each patient is compared to identify deviations from the norm, in order to determine a patient-specific treatment plan. Large inter-individual and inter-ethnic variability, however, is sometimes not considered. In our study, we compared the cephalometric characteristics between two different ethnic groups (South Indian and Vietnamese) with the phenotype of Class II malocclusion in the hope of better understanding this variation and its implications in treatment planning to achieve satisfactory outcomes.

Abstract

The dental, skeletal, and soft-tissue characteristics of a particular malocclusion can differ based on ethnicity, race, age, sex and geographical location with Class II malocclusion being one of the most prevalent malocclusions encountered in orthodontic clinical practice. The broad understanding of the characteristics of vertical skeletal and dental parameters in patients with Class II malocclusion can help clinicians to identify patterns and variations in the expression of this phenotype for better treatment outcomes. Hence, we compared the craniofacial characteristics of skeletal and dental Class II malocclusion traits from Indian and Vietnamese individuals to analyze the vertical skeletal and dental patterns in both population groups. The sample comprised of lateral cephalograms from 100 young adults with Class II malocclusion, of which fifty (25 males and 25 females) were from South India and the other 50 age- and sex-matched adults from Vietnam. The lateral cephalometric radiographs were digitized into anonymous image files and were traced and assessed for 16 vertical skeletal and dental parameters. The ANB angle was greater in males (+1.4 deg; p < 0.001) and females (+1.9 deg; p < 0.001) in the South Indian population. The Vietnamese males had a larger mandibular plane angle, articular angle, anterior facial height and lower anterior facial height compared to the Indian males. The Vietnamese females had larger mandibular plane and articular angles compared to the Indian females. The skeletal class II malocclusion was more severe in the South Indian compared to the Vietnamese adults. The Vietnamese sample showed a generalized tendency towards a more vertical skeletal growth pattern and in males this pattern seemed to be due to the dentoalveolar component. The Vietnamese females showed a tendency towards a vertical growth pattern, but without apparent contribution by the dentoalveolar component.

Dentoskeletal and tooth-size differences between Syrian and Hungarian adolescents with Class II division 1 malocclusion: a retrospective study

Objectives

Malocclusion features differ across various populations and ethnicities. At this time, no data are available regarding the dentofacial differences between Syrian and European adolescents with Class II division 1 malocclusion, which is one of the most frequently treated pathologies in orthodontic practice. The present combined cephalometric and tooth-size study aimed to compare the dentoskeletal and tooth-size characteristics of Syrian and Hungarian adolescents with Class II division 1 malocclusion.

Results

Class II division 1 malocclusion in Hungarian adolescents was a sagittal discrepancy, while in Syrian adolescents, it was a result of excessive vertical development. Syrian adolescents had a significantly excessive vertical development when compared with Hungarian adolescents, regardless of sex (p < 0.01). Hungarian boys had significantly more protruded maxillae (p < 0.001) and less retruded mandibles (p < 0.01) when compared with Syrian boys, while Hungarian girls had significantly shorter mandibles relative to those of Syrian girls (p < 0.01). Syrian girls had significantly more protrusive lower incisors (p < 0.001), accompanied by significantly larger anterior tooth-size ratios when compared to Hungarian girls (p < 0.001). In conclusion, these findings underscore the importance of considering ethnic differences during orthodontic diagnosis and may have implications for optimizing orthodontic treatments in Syrian and Hungarian adolescents with Class II division 1 malocclusion.

[The ethnic factor in dentistry as a component of personalized medicine]

Personalized medicine is the choice of treatment based on the individual characteristics of the patient due to genetic and environmental factors. The latter are to a certain degree determined by an ethnic group. This article discusses ethnic aspects in the structure of the maxillofacial area, the prevalence, development, treatment and prevention of dental diseases.

Evaluation of skeletal variations and establishment of Cephalometric Norms in Saudi Sub Population using Bjork Jarabak's analysis

Objective

To evaluate the skeletal variations amongst individuals and to compare the measurements with the standardized linear and angular values of Bjork Jarabak's analysis.

Methods

This study was conducted at POS Department, King Khalid University on 100 adult Saudi patients recruited through convenience sampling. It was conducted between April to September 2017, had inclusion criteria of patients between the age group 17 to 22 years showing normal occlusion. After history and examinations, lateral cephalographs were taken, scanned and traced using Dolphin Imaging Software and Cephalometric points were recognized. Linear and angular dimensions were calculated according to Bjork-Jarabak's method.

Results

Analysis and assessment of Saudi male and female values revealed considerable variation in the anterior and posterior cranial base lengths (p<0.05), anterior and posterior face height, ramus height, and mandibular length. Male measurements in contrast to Jarabak's values showed noteworthy variances in articular angle, anterior and posterior cranial base, ramus height, length of mandible, anterior face height and Jarabak's ratio. Female dimensions in relation to Jarabak's norms showed considerable variances in articular angle, anterior cranial base, posterior facial height with less significant values in Saudi females while compared with Jarabak's norms apart from mandibular body length which is more in Saudi females.

Conclusion

Skeletal variations amongst Saudi males and females were significant and comparison with standardized linear and angular values of Bjork Jarabak's analysis was also significant.

Comparison of cephalometric variables between adult Spanish and Japanese women with Class I malocclusion

OBJECTIVE

To our knowledge, no study has compared the facial and dental morphology of adult Latin and Japanese populations. The purpose of this study was to assess differences in the facial and dental morphology between adult Spanish and Japanese women with Class I malocclusion using lateral cephalograms.

MATERIALS AND METHODS

The lateral cephalograms of 33 adult Spanish and 33 adult Japanese women were traced and digitized by a single investigator. All patients satisfied the following criteria: female sex; age 18-35 years; skeletal Class I malocclusion (ANB angle, 2°-5°; angle Class I malocclusion; arch length discrepancy, -10 to + 10 mm; overjet, 1-5 mm; overbite, 1-5 mm); absence of congenital anomalies, significant facial asymmetry, or congenitally missing teeth, with the exception of the third molars; significant temporomandibular joint problems; severe crowding; and no history of orthodontic treatment.

RESULTS

Eleven and six angular measurements for the skeletal and dental hard tissues, respectively, were computed in accordance with previous studies. The results showed that Japanese women had significant maxillary and mandibular protrusion, clockwise mandibular rotation, greater labial tipping of incisors, and a smaller interincisal angle compared with Spanish women.

CONCLUSION

At the time of orthodontic treatment planning, it is important to consider the facial and dental morphological characteristics of individual ethnic groups to achieve satisfactory outcomes and retention. The findings of this study provide valuable information that will aid in orthodontic treatment planning for adult Spanish and Japanese women.