This study was undertaken to assess the factors affecting self-perception and the demand for orthodontic treatment among north Jordanian school children. In total, 1404 students randomly selected to represent five geographical areas of northern Jordan were examined. The students were further subgrouped according to gender (858 females, 546 males), age (985 13 year olds, 419 17 year olds) and rural/urban place of residence (212 rural, 1192 urban). The aesthetic component (AC) of the Index of Orthodontic Treatment Need (IOTN) was used as an assessment measure of the need for orthodontic treatment. The self-perception of malocclusion was evaluated by asking each student to identify which photograph on the AC scale most closely matched the appearance of their anterior teeth. The demand for orthodontic treatment was measured by asking the students: ‘Do you feel it is necessary to have your teeth straightened by an orthodontist?’ Differences between the self-perception of malocclusion among the different groups were tested using the chi-squared test. The results showed that the majority of students rated their dentition from grades 1 to 4, with a tendency for the females and older school children to score their teeth as more attractive than males and younger children (P < 0.05, P < 0.001, respectively). Rural and urban school children did not differ in the perception of their own dentition. The self-perception scores of subjects within the no aesthetic need, borderline need and definite need groups differed significantly (P < 0.001). The subjects who reported a definite need perceived their teeth to be worse than the other two groups. The demand for orthodontic treatment was found to be affected by gender (P < 0.01) and rural/urban areas of living (P < 0.05).

The purposes of this study were to rate the attractiveness of different smile variables, to compare the perception of Jordanian laypeople, general practitioners, and orthodontists to altered smile aesthetics, and to identify the threshold where different variables begin to impair smile aesthetics. A smiling photograph of a female dental student was selected and digitally manipulated to create changes in buccal corridor space (BCS), the amount of gingival display, and the midline diastema. These altered images were rated by three groups of Jordanians: 200 laypeople (100 females and 100 males), 200 general practitioners (100 females and 100 males), and 160 orthodontists (40 females and 120 males). Smile aesthetics scores were calculated and comparisons between groups were performed using the univariate general linear model. The results showed that profession and gender affected BCS and midline diastema attractiveness ratings (P < 0.001). Wide BCSs, a gingival display of more than 2 mm, and the presence of a midline diastema of any size were rated as unattractive by all groups.

This study was carried out to record maximum occlusal bite force (MBF) in Jordanian students with three different facial types: short, average, and long, and to determine the effect of gender, type of functional occlusion, and the presence of premature contacts and parafunctional habits on MBF. Sixty dental students (30 males and 30 females) were divided into three equal groups based on the maxillomandibular planes angle (Max/Mand) and degree of anterior overlap: included short-faced students with a deep anterior overbite (Max/Mand ≤ 22 degrees), normal-faced students with a normal overbite that served as the controls (Max/Mand = 27 ± 5 degrees), and long-faced students with an anterior open bite (Max/Mand ≥ 32 degrees). Their age ranged between 20 and 23 years. MBF was measured using a hydraulic occlusal force gauge. Occlusal factors, including the type of functional occlusion, the presence of premature contacts, and parafunctional habits, were recorded. Differences between groups were assessed using a t-test and analysis of variance. The average MBF in Jordanian adults was 573.42 ± 140.18 N. Those with a short face had the highest MBF (679.60 ± 117.46 N) while the long-face types had the lowest MBF (453.57 ± 98.30 N; P < 0.001). The average MBF was 599.02 ± 145.91 in males and 546.97 ± 131.18 in females (P = 0.149). No gender differences were observed. The average MBF was higher in patients with premature contacts than those without, while it did not differ in subjects with different types of functional occlusion or in the presence of parafunctional habits.

Retromolar space has long been identified as a major factor in the aetiology of mandibular third molar impaction. The aims of this study were to compare mandibular third molar space between the different antero-posterior (A-P) skeletal patterns, between erupted and impacted third molars in the different A-P skeletal patterns, and to report on the status of third molar eruption/impaction among the studied subjects. A total of 432 mandibular third molars in 270 subjects (132 females and 138 males) were investigated from dental pantomograms (DPTs) and lateral cephalograms (LC). The average age for the total sample was 20.80 ± 2.03 years. The subjects were divided into three groups according to their ANB angle as follows: skeletal Class I (144 third molars in 90 subjects), skeletal Class II (145 third molars in 95 subjects), and skeletal Class III (143 third molars in 85 subjects). Each group was subdivided into impacted and erupted subgroups. DPT and LC were traced and the following variables were measured: retromolar space width, third molar width and angulation, β angle, second molar angulation, mandibular length, and gonial angle. Independent t-test, analysis of variance, and chi-square test were used for statistical analysis. Retromolar space width in the Class III subjects was smaller than in the Class I subjects (P < 0.05). Mandibular third molars were recorded as impacted in 26, 32, and 42 per cent of the Class I, II, and III subjects, respectively (P < 0.001). The impacted groups had a reduced retromolar space width, increased β angle, and reduced third molar angulation in all A-P skeletal patterns. Class III subjects showed increased mandibular third molar impaction with reduced retromolar space width.