RESUMEN
BACKGROUND/PURPOSE: Tooth size discrepancy is one of the causative factors of malocclusion. This study aimed to establish the TDS among various malocclusion classes and normal occlusion subjects in a Southern Saudi population. MATERIALS AND METHODS: The study casts of orthodontic patients from Southern Saudi Arabia (mean age: 19.6 years ± 2.45; n = 120) were randomly selected and grouped into eight equal classes based on Angle's classification and gender. An additional 30 study casts, devoid of malocclusion, having excellent intercuspation and class I occlusion, were grouped into two controls (n = 15) based on gender. The study casts were three-dimensional scanned to measure mesiodistal widths of all the teeth. The calculated anterior ratios (AR) and overall ratio (OR) were statistically analyzed with analysis of variance and t-tests. RESULTS: There were no significant differences in "OR" and "AR" between the genders (P > 0.05) and among the malocclusion and control subgroups (P > 0.05). The mean "OR" (92.01 ± 0.18) and "AR" (78.60 ± 0.27) of the malocclusion group were significantly higher than that of Bolton's ratios (P > 0.05). The "AR" of the control group was significantly higher than Bolton's standards (P = 0.048). However, "OR" was no different (P = 0.105). Malocclusion patients displayed a discrepancy (±2 standard deviation) in "AR" of 22.5% and 'OR' of 6.7% from Bolton's mean (BM). Similarly, the control group displayed a discrepancy in "AR" of 20% and "OR" of 10% from BM. CONCLUSION: The mean "OR" and "AR" of the Southern Saudi population showed no sexual dimorphism and no significant difference among various malocclusion and control subgroups. The "AR" of the malocclusion and control subgroups did not comply with Bolton's standards.
RESUMEN
Abstract Objective: To determine the proportion of Saudi population in the Asir region that displayed discordance between the facial and maxillary midline and intermaxillary midline, to form an informative guideline for esthetic rehabilitation of patients. Material and Methods: We evaluated 2418 Saudi citizens using positioning guides of the orthopantomography machine to record the relationship of the dental midline to the facial midline. The relationship of the maxillary midline to that of the mandible was observed clinically, and diagnostic mounting of particular cases was performed for confirmation. The examination was carried out by four trained observers (two dentists and two radiology technicians) to overcome the parallax effect. The cases with disagreements were repeated. The record was grouped into (1) coincidence, (2) deviation of the mandible to the right, and (3) deviation to the left. The relationship between facial-dental midline concordance and intermaxillary concordance was assessed using the Chi-squared test Results: Facial and maxillary midline did not coincide in 42.5% participants, whereas intermaxillary midline discordance was observed in 51.5%. Among those exhibiting discordance, 57% had right discordance and 43% had left discordance Conclusion: A significant proportion of the population displayed discordance between the facial-maxillary midline as well as the intermaxillary midline. The female population showed not only a higher number of intermaxillary discordance than males but also a significant number of intermaxillary discordance towards the right.
