A retrospective investigation of orthognathic patients and functional needs

Abstract

Purpose The present study aimed to explore the malocclusion trends, sagittal skeletal discrepancies, and the index of orthognathic functional treatment need (IOFTN) scores in a sample of Iranian and Turkish orthognathic patients. Methods Four hundred and three orthognathic patients were retrospectively examined (203 Iranian/200 Turkish, 229 females/174 males, aged between 16 and 50 years). The following variables were recorded: malocclusion type (incisor-based), overjet, sagittal skeletal relationship (ANB angle) and IOFTN scores. The sagittal skeletal relationships and malocclusion patterns of the orthognathic patients were statistically examined using Chi-square tests and further explored graphically. The relationship between the IOFTN scores and overjet, as well as the sagittal skeletal discrepancies (ANB angle) was evaluated using box plots and at the 95% confidence interval (CI) in different IOFTN treatment categories (1–3,4,5). The characteristics of a subgroup sample of orthognathic patients and previous studies that identified with low IOFTN scores (1–3) were also explored. Results Class III malocclusions and Class III skeletal patterns were the most prevalent (62.3%), forming 69% and 55.7% of the Turkish and Iranian samples, respectively. Turkish and Iranian samples had more Class III [Mean (SD) ANB angle = -1.24° (4.75°)] and Class II cases [Mean (SD) ANB angle=1.06° (5.63°)], respectively. The mean overjet and reverse overjet for Class II and III malocclusions were 6.96 mm (95% CI, 6.40–7.53 mm) and 3.26 mm (95% CI, 2.87–3.65 mm), respectively. The mean ANB angle for Class II and III malocclusions was 6.64° (95% CI, 6.15°–7.13°) and -3.57° (95% CI, -3.92° to -3.21°), respectively. IOFTN scores of 4 or 5 were identified in 93.8% of the sample. Patients with low IOFTN scores (<4) presented with a nearly normal overjet (mean = 3.19 mm, 95% CI, 2.62-3.76 mm, range = 1–5 mm), accompanied by a wide range of ANB angles [mean (SD)=3.44° (3.86°), range = -4° to 9°] Conclusions The findings at the 95% CI for overjet and the ANB angle can be used as identifiers for patients who would benefit from orthognathic surgery. Analysing patients with a low IOFTN score, particularly with scores of 3.3, 3.10, 2.8, and 1.14, revealed that IOFTN could be used in conjunction with a clinical examination plus diagnostic imaging to facilitate the identification of orthognathic surgery patients.