Tooth size discrepancies in Class II division 1 and Class III malocclusion requiring surgical-orthodontic or orthodontic treatment.

OBJECTIVE: To compare mean anterior (AR) and mean overall (OR) tooth size ratios, prevalence of clinically significant tooth size discrepancies (TSDs) and correlation between AR and OR in subjects with Class II division 1 and Class III malocclusion treated by surgical-orthodontic or orthodontic means. DESIGN: Retrospective, cross-sectional. SETTING: State-funded and private clinics. PARTICIPANTS: From pre-treatment cohorts of 770 surgical and 610 non-surgical subjects, Class II division 1 and Class III malocclusion groups were identified with 60 surgical and 60 non-surgical subjects, comprising 30 males and 30 females, in each. METHODS: AR and OR were calculated by landmarking digital models. Differences in AR and OR and their relationship were analysed using two-way analysis of variance (ANOVA) and a correlation coefficient, respectively. The proportions of the surgical and non-surgical groups with a TSD were assessed using logistic regression. Intra-examiner reproducibility involved re-landmarking 30 randomly selected image sets and differences in ARs and ORs were compared using a paired t-test. Random error was assessed using the intraclass correlation coefficient (ICC). Analyses were performed using SAS (SAS Institute Inc., Cary, NC, USA) at the 5% level of significance. RESULTS: There were no statistically significant differences associated with the measurement of either the mean AR (P = 0·913) or the mean OR (P = 0·874). ICC values were very high (AR = 0·95; OR = 0·90). Differences existed between both Class II and Class III surgical (AR: P<0·001; OR: P<0·001) and non-surgical groups (AR: P = 0·012; OR: P = 0·003). The AR and OR relationship was strong (correlation coefficient = 0·72). The highest percentage of clinically significant TSDs was seen in the AR of both Class II and Class III surgical groups (23·3%). CONCLUSIONS: In the cohort examined: AR and OR differed significantly for malocclusion groups. The prevalence of clinically significant TSDs did not differ significantly between surgical and non-surgical groups although the highest percentage of clinically significant TSDs was recorded for AR in Class II and Class III surgical cases. AR and OR were closely related.

North Cork HSE orthodontic treatment waiting list 2009-2010: retrospective audit of patient records.

PURPOSE OF THE STUDY: To evaluate the case profile and verify the treatment eligibility (based on the modified IOTN) from written case records, of patients accepted for orthodontic treatment from the North Cork area of HSE South. MATERIALS AND METHODS: A data collection form was designed and applied to the written case records of 200 consecutive patients accepted for orthodontic treatment in 2009/2010. Data relating to the IOTN (DHC and AC, where relevant) were provided by a calibrated examiner. RESULTS: Based on the written case records, most (57%) of the treatment cohort were female and had an average age of 14 years and two months. The predominant malocclusion was Class II division 1 (40%). The prevalence of Class III malocclusion was high at 18%. A total of 61% of patients were in grade 5 and 36% in grade 4. The majority of patients in each of these grades fell into DHC 5a (32%), followed by 5i (24%) and 4d AC > 8 (16%). CONCLUSIONS: Written case records conclude that patients accepted for orthodontic treatment from the North Cork area of HSE South were predominantly female. Class II division 1 malocclusion was the most common accepted for treatment. These records verify that those patients accepted for orthodontic treatment satisfy the eligibility criteria for HSE treatment.