Relationship between dental arch width and vertical facial morphology in untreated Indian population

Introduction: Facial growth pattern is an important factor in planning orthodontic treatment properly. Knowledge of arch forms is important for an orthodontist, as it is related to future treatment outcome. Factors such as age, sex, and ethnicity are also important. The purpose of present study was to evaluate the dental arch dimensions in a different facial pattern in regional population, to evaluate correlation in the facial pattern with dental arch width to evaluate the differences in dental arch width between male and female subjects.
Materials: The present study was conducted on 120 untreated subjects comprising of 60 males and 60 females aged between 16 to 38 years. The Jarabak’s ratio (posterior facial height/anterior facial height) was measured on cephalograms of each patient. Maxillary and mandibular inter-canine, first inter-premolar, second inter-premolar and first inter-molar widths were measured on study models of each patient.
Results: There was no significant correlation between dental arch width and vertical facial pattern in regional population. In males, arch width is greater in canine, premolar and molar region than females.
Conclusion: It was concluded that dental arch width is not associated with the vertical facial pattern but it is associated with gender. Thus, using individualized arch wires according to gender is suggested during orthodontic treatment.
Bangladesh Journal of Medical Science Vol.23 (Special Issue) 2024 p.S26-S31


Introduction
Facial growth pattern is an important factor in planning orthodontic treatment properly as it influences the anchorage system and growth prediction of maxillofacial structures.Knowledge of arch form is also important in clinical orthodontics as it is related to the treatment outcome.It is generally accepted among orthodontists that a relationship exists between dental arch width and vertical facial

Introduction
Facial growth pattern is an important factor in planning orthodontic treatment properly.Knowledge of arch forms is important for an orthodontist, as it is related to future treatment outcome.Factors such as age, sex, and ethnicity are also important.The purpose of present study was to evaluate the dental arch dimensions in a different facial pattern in regional population, to evaluate correlation in the facial pattern with dental arch width to evaluate the differences in dental arch width between male and female subjects.

Materials
The present study was conducted on 120 untreated subjects comprising of 60 males and 60 females aged between 16 to 38 years.The Jarabak's ratio (posterior facial height/anterior facial height) was measured on cephalograms of each patient.Maxillary and mandibular inter-canine, first inter-premolar, second interpremolar and first inter-molar widths were measured on study models of each patient.

Results
There was no significant correlation between dental arch width and vertical facial pattern in regional population.In males, arch width is greater in canine, premolar and molar region than females.

Conclusion
It was concluded that dental arch width is not associated with the vertical facial pattern but it is associated with gender.Thus, using individualized arch wires according to gender is suggested during orthodontic treatment.morphology.According to Ricketts et al (1982)  1 , Enlow and Hans (1996) 2 and Wagner and Chung (2005) 3 , a long face individual usually has narrower arch dimensions and a short face individual has wider arch dimensions.Therefore, the question arises is there any relation between vertical facial morphology and dental arch width.Also, there is any difference in arch widths between male and female.Several studies have been conducted on this topic, but their results were inconclusive.According to the study conducted by Howes (1957) 4 individuals with steep mandibular plane (MP) generally had larger teeth and narrower and shorter arches than individuals with flat mandibular plane when measured from the buccal cusp tips of the maxillary first premolars.Isaacson et al (1971)  5 concluded that subjects with longer faces presented with a decrease in maxillary inter-molar width.But they did not distinguish between males and females.
In terms of the difference in arch width between males and females, Wei conducted a study in which he evaluated PA cephalograms of Chinese adults and noted gender differences in maxillary and mandibular intercanine widths.According to Eroz et al 6 in children, males had significantly larger inter-molar widths when compared with females.C.Matthew Forster 7 compared the relationship between dental arch width and vertical facial morphology.
The extreme types of vertical facial dysplasia have been described as hypo divergent and hyper divergent 8 or short face syndrome (SFS) and the long face syndrome (LFS) 9 .
It is suggested that individualized arch wires should be used during orthodontic treatment but nowadays preformed arch wires are used by orthodontist without considering the facial type, gender, and ethnicity.The purpose of the present study was to evaluate the dental arch dimensions in the different facial patterns in regional population, to evaluate correlation in the facial pattern (Jarabak's ratio) with dental arch width in a regional population of Marathwada and to evaluate the differences in dental arch width between male and female subjects.

MATERIALS AND METHODS
The present study was conducted on 120 untreated subjects comprising of 60 males and 60 females ages between 16 to 38 years.The lateral cephalograms and study models for the purpose of the study were obtained from the records of patients visiting the Department of Orthodontics and Dentofacial Orthopaedics.Subjects were selected on the basis of following inclusion and exclusion criteria.

Inclusion criteria-
• A full dentition except third molars.
• Maxillary and mandibular dental casts available.
• History of trauma.
• Severe crowding (>9 mm) or spacing (>9 mm).The Jarabak's ratio (posterior facial height/anterior facial height) was measured on cephalograms of each patient.Then subjects were divided into three groups i.e. 1) average growth pattern (Jarabak's ratio -62-65%), 2) Horizontal growth pattern (Jarabak's ratio <61%), 3) vertical growth pattern (Jarabak's ratio >65%).Maxillary and mandibular inter-canine (from cusp tip of one side canine to cusp tip of opposite side canine) , first inter-premolar (from buccal cusp tip of one side 1 st premolar to buccal cusp tip of opposite side 1 st premolar), second inter-premolar (from buccal cusp tip of one side 2 nd premolar to buccal cusp tip of opposite side 2 nd premolar) and first inter-molar (from mesio-buccal cusp tip of one side 1 st molar to mesiobuccal cusp tip of opposite side 1 st molar) widths were measured on study models of each patient.Vernier calliper was used to measure the parameters: intercanine width, first inter-premolar width, second interpremolar width, first inter-molar width.

Statistical analysis and methods
Data was collected using a structured proforma.Data entered in MS excel sheet and analysed by using SPSS 23.0 version IBM USA.
Quantitative data were expressed in terms of Mean ©The Ibn Sina Trust S 28 and Standard Deviation Comparison of mean and SD between two groups was done by using the unpaired t-test to assess whether the mean difference between groups is significant or not Descriptive statistics of each variable was presented in terms of Mean, standard deviation, standard error of the mean.Comparison of mean and SD between all groups was done by using one-way ANOVA test.If ANOVA comes significant, then Post Hoc Tukey's HSD test was carried out to assess whether the mean difference between a pair of a group is significant or not A p value of <0.05 was considered as statistically significant whereas a p-value <0.001 was considered as highly significant.

RESULTS
Table 1 shows the mean and standard deviation values of arch dimension measurements of male and female subjects.As seen, males have larger means for dental arch width as compared to the female subjects.Table 2 shows a significant correlation between arch width and gender except in mandibular inter-canine and 1 st interpremolar width and maxillary inter-molar width.
The arch width measurements of horizontal, average and vertical growth pattern groups are presented in Table 3 which statistical analysis does not show significant correlation between growth pattern and dental arch widths except in maxillary first premolar, maxillary and mandibular first molar region which showed significant results.  .They found that males had sufficiently larger arch widths as compared with females.Jarabak's and Siriwat (1985) 13 , Bishara and Jakobsen (1985) 14 had also found a sexual dimorphism to exist among various facial types.
For maxillary and mandibular arches, there was a statistically significant relationship between dental arch width and gender at the maxillary canine, first premolar, second premolar and first molar region except in mandibular inter-canine and 1 st inter-premolar width and maxillary inter-molar width.In males, arch width is more as compared to females.Similar findings have also been reported by the Eroz et al (2000) 6 and Forster et al (2008) 7 .
The arch width measurements of horizontal, average and vertical growth pattern show that in majority cases the vertical group had smaller mean arch widths as compared to horizontal and average growing subjects, but the statistical analysis does not show a significant correlation between growth pattern and dental arch widths.Dental arch width means decrease as Jarabak's ratio value increases in all regions except in Maxillary and mandibular 2 nd inter-premolar width and mandibular inter-molar width in these regions arch widths in average growing subjects is slightly greater than horizontal growing subjects.The majority of the studies show a significant correlation between vertical facial pattern and arch width but the present study did not show a significant correlation between vertical facial morphology and arch width.This non-significant correlation between three groups and arch widths may be due to ethnic variation or may be due to small sample size.

CONCLUSION
Based on the results and discussions above, it can be concluded that; 1) The dental arch widths of males were found to be wider than females among untreated adult's population.

2)
Vertical facial morphology did not show a relationship with arch width of upper and lower dental arches at the canine, first premolar, second premolar, and first molar regions.

Consent for Publication:
The author reviewed and approved the final version and has agreed to be accountable for all aspects of the work, including any accuracy or integrity issues.

Disclosure:
The author declares that they do not have any financial involvement, association, or entity directly or indirectly with the subject matter or materials presented in this editorial.This includes honoraria, expert testimony, employment, ownership of stocks or