OBJECTIVE: The study aimed to assess the accuracy and reliability of five cephalometric parameters in diagnosing class III malocclusion in Saudi and Yemeni population. MATERIAL AND METHODS: A cross-sectional, descriptive study in which total 60 lateral cephalograms (30 of Saudi and 30 of Yemeni population) of Class III malocclusion were hand-traced. ANB angle, Wits appraisal, Beta angle, W angle, and Yen angle were measured. The validity, reliability, sensitivity, and positive predictive values (PPVs) of these parameters were calculated. RESULTS: In Saudi population, a strong correlation was found between ANB angle and Wits appraisal (r = 0.892, P < 0.05), ANB and Beta angle showed highest sensitivity (0.933) followed by Wits appraisal (0.900), and ANB angle showed the highest PPV (0.965) followed by Beta angle (0.933) and Wits appraisal (0.931). In Yemeni population, a strong correlation was found between ANB angle and Wits appraisal (r = 0.887, P < 0.05), ANB angle and W angle showed highest sensitivity (0.966) followed by Wits appraisal (0.933), whereas W angle showed the highest PPV (1.00) followed by ANB angle (0.966) and Wits appraisal (0.933). CONCLUSION: In Saudi population, ANB angle and Beta angle, whereas in Yemeni population, ANB angle and W angle are the most valid cephalometric indicators to accurately assess the class III malocclusion. ANB angle in the Saudi population and W angle in the Yemeni population have the highest PPV in correctly diagnosing class III malocclusion.

OBJECTIVE: To evaluate the skeletal, dental and soft tissue cephalometric changes by addition of daytime Class III elastics to the Alternate Rapid Maxillary Expansion-Constriction (AltRAMEC) and Reverse Headgear (RH) protocol in skeletal Class III patients with maxillary retrusion. Material and Methods: 54 patients with maxillary retrusion and CVMI (Cervical vertebral maturity index) <CS3 were randomly allocated to an AltRAMEC/RH group (group 1) and AltRAMEC/RH/Class III elastics group (group 2). Each group underwent 5 weeks of AltRAMEC using bonded RME (Rapid Maxillary Expansion) appliance, followed by reverse headgear therapy with a Petit type facemask for 4-5 months. The protraction so obtained was maintained by the use of daytime Class III elastics in group 2. A total of twenty skeletal, dental and soft tissue parameters were evaluated by a blinded examiner. Results were evaluated statistically. Results: Significant forward movement of the maxilla with counter-clockwise rotation, improved intermaxillary relationships, downward and backward movement of the mandible, and favourable soft tissue changes were observed in both the groups under study. The results were more pronounced in group 2. Increase in vertical dimensions, proclination of maxillary and retroclination of mandibular incisors was also observed. Statistically significant differences were present between the two groups for all of the maxillary and mandibular skeletal, intermaxillary and two of the soft tissue parameters tested; while the differences were not found to be significant for dental parameters. Conclusion: Addition of Class III elastics to the AltRAMEC/RH protocol yielded more pronounced, favourable and statistically significant results.

OBJECTIVE: To compare airway widths among skeletal Class I malocclusion patients with different vertical facial patterns. MATERIAL AND METHODS: A total of 103 lateral cephalograms of skeletal Class I patients (mean age of 20 ± 2.3 years) with no history of orthodontic treatment, trauma, facial syndromes, or nasopharyngeal dysfunction were included. Based on the Frankfort–mandibular plane angle measurements, the sample was divided into three groups: low-angle, high-angle, and normal-angle groups. Upper and lower pharyngeal airway widths were measured as described by McNamara. The analysis of variance test was performed to compare the means of groups. Pairwise comparisons were performed using Tukey's post-hoc test. Differences were considered statistically significant at P < 0.05. RESULTS: ANOVA showed a significant mean difference between the groups for both the upper and lower airway widths withP values of 0.011 and 0.003, respectively. Tukey Pairwise comparisons showed the upper airway width to be significantly narrower in the high-angle group compared to the normal-angle (P = 0.021) and low-angle groups (P = 0.013). Furthermore, the lower airway width in the high angle group was significantly narrower than the normal angle (P = 0.020) and low-angle groups (P = 0.017). There were no statistically significant differences between normal and low angle groups. CONCLUSIONS: The upper and lower pharyngeal widths in the Class I high-angle group were significantly narrower than those in the normal-angle and low-angle groups.

OBJECTIVE: To compare dental and skeletal ages among African American (AA), Caucasian (C) and Hispanic (H) subjects (chronological ages 9 to 15-years). MATERIAL AND METHODS: A total of 168 subjects (9 to 15 years old) were equally divided into AA, C, and H groups, with an equal number of males and females. Each group was divided equally into 7 chronological age-groups, ranging from 9 to 15 years. Dental age was determined from panoramic radiographs as primary, early mixed, late mixed, or permanent dentition (scored as 1-4). Skeletal age was calculated from hand-wrist radiographs using Fishman's Skeletal Maturation Index (SMI 1-11). One-way analysis of variance and Tukey's test were used to compare skeletal and dental ages among AA, C and H subjects; and AA, C and H subjects in each chronological age-group. The two-sample t-test was used to compare SMI and dental age among females and males. RESULTS: Skeletal and dental age were not significantly different between AA, C and H subjects. Mean SMI was higher in females than males; and there were no significant gender differences regarding dental age. Mean SMI and dental age were significantly different among AA, C and H subjects in the 12-year-old and 11-year-old age groups, respectively. CONCLUSIONS: Dental and skeletal maturation are fairly similar among AA, C and H subjects (aged 9 to 15 years).

OBJECTIVE: This study aimed to assess the feasibility of reusing nickel–titanium (NiTi) alloy wires after 6 weeks of intraoral use by evaluating the changes in the load-deflection properties and surface characterization of these alloy wires after cold sterilization by immersion in 2% of acidic glutaraldehyde for 10 h. MATERIAL AND METHODS: Twenty wires each in three groups of G1-as-received wires (ARW), G2-unsterilized used wires, and G3-sterilized used wires (SUW) were tested by the three-point bending test and scanning electron microscopy (SEM). The data were subjected to statistics, one-way analysis of variance, and Bonferroni posthoc test for comparison. RESULTS: Recycling of NiTi wires produced statistically insignificant changes in both the loading and unloading properties of the wires. The forces needed to twist the used wires, that is, G2-(UUW) and G3-(SUW) were lower than G1-(ARW), suggesting lowering of the stiffness of the wires. Superelasticity is well-maintained by G2-(UUW) and G3-(SUW) although there is an insignificant lowering of the forces exerted by them during loading and unloading. SEM demonstrated no increase in the pitting of surfaces in both G2-(UUW) and G3-(SUW); multiple areas were seen to be more smoothened over G2-(UUW) and G3-(SUW) NiTi wires surfaces. CONCLUSION: The findings of this study support the reuse of NiTi wires after 6 weeks of use in oral conditions followed by cold sterilization by immersion in 2% acidic glutaraldehyde for 10 h.