A comparative study of initial changes in pulpal blood flow between clear aligners and fixed orthodontic appliances.

INTRODUCTION: The objective of this study is to evaluate and compare the initial changes of pulpal blood flow (PBF) using clear aligner and fixed orthodontic treatment. METHODS: A total of 45 subjects were subdivided into 2 groups: group 1; 25 subjects treated with preadjusted edgewise fixed appliance with 0.014″ nickel titanium as the alignment archwire and group 2; 20 subjects treated using clear aligner. In both groups, PBF was measured for the maxillary right and mandibular left teeth using Laser Doppler flowmetry at different time intervals (20 minutes, 48 hours, 72 hours, and 1 month) after the fitting of the nickel titanium archwire in group 1 and after the delivery of the second aligner in group 2. A repeated-measures analysis of variance and a Bonferroni post-hoc comparison test were applied to determine differences at the various time intervals. RESULTS: The PBF decreased in both types of appliances after force application. The maximum reduction in PBF was reached after 72 hours. It returned to its normal values within 1 month. The differences in PBF between the 2 groups did not reach any statistical significance. CONCLUSIONS: PBF in orthodontically treated teeth decreased 20 minutes after orthodontic force application in both fixed and clear aligner appliances. In both treatment groups, most changes occurred within 48 hours of force application. PBF returned to its normal values within 1 month. Changes in PBF in both treatment groups were comparable.

Force degradation of orthodontic latex elastics: An in-vivo study.

INTRODUCTION: Our objectives were to assess the force degradation of orthodontic latex elastics over 48 hours in vivo and to study the relationship between the amount of mouth opening and the degree of force decay. METHODS: Fifty-two orthodontic patients wearing fixed appliances using Class II elastics were asked to wear premeasured-force 3/16-in heavy and medium intermaxillary elastics. The force amounts were measured and compared at different time intervals. RESULTS: Fifty percent of the force was lost after 3.9 hours for the medium elastics and after 4.9 hours for the heavy elastics. A continuous significant force drop in all elastics was seen at all time intervals (P <0.05, P <0.001). There was greater force loss in the heavy elastics compared with the medium elastics in vivo at all time intervals (P <0.001); the rates of force loss, however, were similar. CONCLUSIONS: Fifty percent of force degradation occurred in the first 4 to 5 hours. Because of breakage and for oral hygiene purposes, orthodontic elastics should be changed daily; otherwise, elastics can be used for 48 hours. Force decay of the elastics was correlated to the lateral distance between the maxillary canine and the mandibular first molar in occlusion.

Acceptability and attractiveness of intra- and extra-oral orthodontic appliances.

OBJECTIVES: To evaluate the acceptability of different intra-oral and extra-oral orthodontic appliances, to rank orthodontic appliances from the most to the least attractive and to investigate the factors that may affect the acceptance of orthodontic treatment. SUBJECTS: A random sample of 800 students (schoolchildren and university students) were invited to participate in this study and a total of 688 students were included (86%). METHODS: A self-administrated structured questionnaire was constructed for the purpose of this study. RESULTS: More than one-half in each age group (53%) claimed that they would accept to have orthodontic treatment. Acceptance of the different orthodontic appliances was affected by gender, age and type of school. Removable appliance was reported as the most acceptable and facemask was reported as the least acceptable orthodontic appliances. Majority of subjects ranked ceramic and facemask appliances as the most and the least attractive orthodontic appliances, respectively. The predictor variables for the acceptance of orthodontic treatment were perceived demand for orthodontic treatment, perceived positive effect of orthodontic treatment and expected benefits from orthodontic treatment. CONCLUSIONS: Removable appliance was the most acceptable orthodontic appliance whereas ceramic appliance was ranked as the most attractive one. Facemask was the least acceptable and the least attractive option.

Maximum occusal bite force for children in different dentition stages.

This study was carried out to record maximum occlusal bite force (MOBF) among different dentition stages in children and to study the relation of occlusal bite force to weight, height, and gender. A total of 1011 children (500 females and 511 males) aged from 3 to 18 years were examined. The subjects were divided into 5 groups according to their dentition stage as the following:- early primary dentition stage (100 males and 100 females, average age was 3.37 ± 0.23 years), late primary dentition stage (104 males and 100 females, average age was 5.86 ± 1.15 years), early mixed dentition stage (100 males and 100 females, average age was 8.15 ± 0.67 years), late mixed dentition stage (100 males and 100 females, average age was 9.97 ± 0.86 years ), and permanent dentition stage (107 males and 100 females, average age was 14.03 ± 2.14 years). Occlusal bite force was measured using a hydraulic occlusal force gauge. The means of MOBF for the different dentition stages were:- 176 N in early primary stage, 240 N in late primary stage, 289 N in early mixed stage, 433 N in late mixed stage, and 527 N in the permanent dentition stage, respectively. Gender differences were detected in groups 2, 3 and 4. Height and age significantly correlated with the MOBF in all dentition stage groups except group 1. In conclusion, the MOBF increased with age. Age, gender, and height were significant predictors of the MOBF.

Skeletal, dental and soft tissue changes in Class III patients treated with fixed appliances and lower premolar extractions.

BACKGROUND: Mild Class III malocciusions can be treated by upper incisor proclination and lower incisor retroclination following extraction of the lower first premolars. AIMS: To compare the skeletal, dental and soft tissue changes in Class III patients treated with fixed appliances, Class III traction and lower first premolar extractions with the changes in a group of untreated Class III patients. METHODS: The Treatment group consisted of 30 Class III patients (Mean age 13.69 +/- 1.48 years) who were treated by upper and lower fixed appliances, Class III intermaxillary traction and lower first premolar extractions for 2.88 +/- 1.12 years. The Control group consisted of 20 untreated Class III patients (Mean age 13.51 +/- 0.95) matched for age and gender. The T1 to T2 changes in the treated and untreated groups were compared using a paired t-test while differences between the two groups were compared with an independent t-test. RESULTS: During treatment, the upper incisors were proclined about 1 degree and the lower incisors were retroclined 8 degrees. Small, but statistically significant changes in SNB, Wits and the overlying soft tissues accompanied the changes in incisor inclination. At the end of treatment a positive overbite and overjet were achieved. The increase in lower facial height in the Treatment group was comparable with the change in the Control group. CONCLUSIONS: A range of mild to moderate Class III malocclusions can be treated by dentoalveolar compensation.

Perceptions of Jordanian laypersons and dental professionals to altered smile aesthetics.

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.

Factors affecting the shear bond strength of metal and ceramic brackets bonded to different ceramic surfaces.

The aims of this study were to evaluate the shear bond strength (SBS) of metal and ceramic brackets bonded to two different all-ceramic crowns, IPS Empress 2 and In-Ceram Alumina, to compare the SBS between hydrofluoric acid (HFA), phosphoric acid etched, and sandblasted, non-etched all-ceramic surfaces. Ninety-six all-ceramic crowns were fabricated resembling a maxillary left first premolar. The crowns were divided into eight groups: (1) metal brackets bonded to sandblasted 9.6 per cent HFA-etched IPS Empress 2 crowns; (2) metal brackets bonded to sandblasted 9.6 per cent HFA-etched In-Ceram crowns; (3) ceramic brackets bonded to sandblasted 9.6 per cent HFA-etched IPS Empress 2 crowns; (4) ceramic brackets bonded to sandblasted 9.6 per cent HFA-etched In-Ceram crowns; (5) metal brackets bonded to sandblasted 37 per cent phosphoric acid-etched IPS Empress 2 crowns; (6) metal brackets bonded to sandblasted 37 per cent phosphoric acid-etched In-Ceram crowns; (7) metal brackets bonded to sandblasted, non-etched IPS Empress 2 crowns; and (8) metal brackets bonded to sandblasted, non-etched In-Ceram crowns. Metal and ceramic orthodontic brackets were bonded using a conventional light polymerizing adhesive resin. An Instron universal testing machine was used to determine the SBS at a crosshead speed of 0.1 mm/minute. Comparison between groups was performed using a univariate general linear model and chi-squared tests. The highest mean SBS was found in group 3 (120.15 +/- 45.05 N) and the lowest in group 8 (57.86 +/- 26.20 N). Of all the variables studied, surface treatment was the only factor that significantly affected SBS (P < 0.001). Acid etch application to sandblasted surfaces significantly increased the SBS in groups 1, 2, 5, and 6. The SBS of metal brackets debonded from groups 1, 3, and 5 were not significantly different from those of groups 2, 4, and 6. All debonded metal brackets revealed a similar pattern of bond failure at the adhesive-restorative interface. However, ceramic brackets had a significantly different adhesive failure pattern with dominant failure at the adhesive-bracket interface. Ceramic fractures after bracket removal were found more often in groups 1-4. No significant difference in ceramic fracture was observed between the IPS Empress 2 and In-Ceram groups.

Maximum occlusal bite forces in Jordanian individuals with different dentofacial vertical skeletal patterns.

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 < or = 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 > or = 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.

Periodontal parameters in different dentofacial vertical patterns.

OBJECTIVE: To assess periodontal parameters in a Jordanian population in individuals with three different facial types. MATERIALS AND METHODS: Forty-five dental students (ages 20-26 years) with short, average, and long face heights were divided into three equal groups. The plaque index, gingival index, gingival thickness, width of keratinized gingiva, and width of attached gingiva were measured in each group. Occlusal factors, including the dynamic occlusion and the presence or absence of premature contacts were recorded. Differences among the three groups were assessed using Student's t-test, chi-square test, and analysis of variance (ANOVA) test. RESULTS: No differences were present in the plaque index, gingival index, gingival attachment, width of attached and keratinized gingiva and gingival thickness between the subjects in the three groups studied. None of the subjects in the long face group had canine guidance dynamic occlusion. CONCLUSIONS: There were no differences in the periodontal parameters between the different dentofacial vertical patterns, but there was a difference in the canine guidance dynamic occlusion.

Shear bond strength of orthodontic brackets bonded to different ceramic surfaces.

This study was undertaken to measure the shear bond strength (SBS) of stainless steel brackets bonded to different ceramic surfaces, to compare the SBS of the different ceramics with each other and with conventional ceramo-metal porcelains, and to determine the mode of failure for each group following debonding. A total of 60 ceramic crowns were constructed on extracted teeth and divided into three equal groups as follows: In-Ceram ceramic crowns, IPS-Impress ceramic crowns, and conventional ceramo-metal porcelain. Standard edgewise metal premolar brackets were bonded to the prepared porcelain surfaces. After bonding, all samples were tested in shear mode on an Instron universal testing machine. Statistical analysis was undertaken using analysis of variance, LSD, and chi-squared tests. The results showed that the SBS for the ceramo-metal and the In-Ceram groups were comparable, with mean values of 80.54 +/- 13.44 N and 78.87 +/- 13.47 N, respectively. The IPS-Impress group showed the weakest SBS which averaged 67.40 +/- 8.99 N. This was significantly lower than that of the conventional ceramo-metal porcelain (P < 0.001) and the In-Ceram surface (P < 0.01). The mode of failure in the ceramo-metal group was between the porcelain surface and adhesive and in the other two ceramic groups, between the brackets and adhesive (P < 0.001). The SBS of orthodontic brackets to the three tested ceramic surfaces were adequate for orthodontic use.

Relationship between tooth irregularity and periodontal disease in children with regular dental visits.

OBJECTIVES: The aim of this study was to investigate any association between irregular teeth and periodontal breakdown among children who attend dental clinics regularly. METHODS: The subjects were 80 children (39 females and 41 males) with a mean age of 12.38 +/- 0.75 years. Each subject had an alginate impression in the mandibular arch, periapical radiographs for the lower incisor teeth and clinical examination for periodontal health. Plaque accumulation, gingival condition and probing depth, bone level and status of lower incisor teeth contact areas were recorded. Spearman correlation test was used to observe any relationship between the clinical variables. RESULTS: The average probing depth, gingival index and plaque index scores in the subjects studied were 1.3 +/- 0.25, 0.99 +/- 0.28 and 1.17 +/- 0.52 respectively. The average number of sites with labiolingual displacement with mesiodistal overlap was 1.81 +/- 1.30 and those without mesiodistal overlap was 1.39 +/- 1.10. The average number of contact areas with spacing was 0.59 +/- 1.23. The correlation observed between irregularity and periodontal health indicated no association between the number and type of displacement and plaque accumulation, gingivitis, attachment loss and alveolar bone level. CONCLUSION: There was no association between irregularity of teeth and periodontal diseases in presence of good oral hygiene.

Tooth size discrepancies and arch parameters among different malocclusions in a Jordanian sample.

The objectives of this study were to determine the mean mesiodistal tooth width of the dentition, Bolton anterior and overall ratios, arch length, and arch width in the different malocclusions in a Jordanian sample. The mesiodistal tooth width, arch width, and length were measured on a total of 140 orthodontic models of school students aged 13-15 years of different occlusal relationships (Class I, Class II division 1, Class II division 2, and Class III malocclusions). Anterior and overall Bolton ratios were calculated. The mean and standard deviation were calculated. Student's t-test and analysis of variance were used for the statistical analysis. The results show that (1) females have smaller teeth than males; (2) Class III malocclusion showed larger teeth than the rest of the other occlusal categories; (3) no statistically significant differences were found in Bolton ratios between the different malocclusions; (4) Class II division 1 showed the narrowest maxillary arch compared with the other types of malocclusion; (5) the mandibular intercanine width was significantly larger in Class III group than in Class II division 1 and Class II division 2 groups; (6) the maxillary arch was significantly longer in Class II division 1 than in Class II division 2; and (7) the mandibular arch of both Class II categories was significantly shorter than Class III malocclusion group. In conclusion, tooth size differences were found between right and left sides, between females and males, and between the different malocclusions. Arch width and length also showed differences among the different malocclusions.

Prevalence of malocclusion in 13-15 year-old North Jordanian school children.

OBJECTIVES: This study was carried out to determine the prevalence of malocclusion in 13-15-year-old North Jordanian schoolchildren. METHODS: One thousand and three children aged 13-15 years (619 females, 384 males) were examined using Björk et al. (1964) registration method. A full clinical examination was carried out in the school premises using a mouth mirror under natural lighting. Alginate impressions were then taken for each student together with a wax bite. The impressions were poured the same day by an orthodontic technician. Peri-apical radiographs were taken for the students when hypodontia was suspected. RESULTS: Overall, the prevalence of malocclusion was 92%. Class II and III molars were found in 18.8% and 1.4% of the sample respectively. The malocclusion traits detected were crowding (50.4%), midline shift (31.7%), spaced dentition (26.7%), increased overjet (24.7%), deepbite (16.9%), crossbite (6.8), abnormal tooth form (7.7%), median diastema (6.9%), missing teeth (6%), ectopic canines (5.9%), inverted incisors (5.2%), high frenal attachment (3.9%), openbite (2.9%), tooth impaction (1.8%), reversed overjet (1.9%), scissorbite 0.3%. There was no statistically significant difference between males and females in the overall prevalence of malocclusion and the occlusal traits investigated. However, some dental anomalies showed significant differences. CONCLUSIONS: Prevalence of malocclusion among north Jordanians is comparable with other populations.

Self-perception of malocclusion among north Jordanian school children.

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).

Attractiveness ratings of anterior open bites and reverse overjets using the aesthetic component of the Index of Orthodontic Treatment Need.

This study was carried out to determine the level of attractiveness of anterior open bites (AOB) and reverse overjets of varying severity. A sample of 180 non-dental students (101 females and 79 males; average age 20 +/- 0.75 years) and 45 dental professionals (12 females and 33 males; average age 35.5 +/- 5.07 years) was asked to complete a questionnaire to rate the level of attractiveness of AOB and reverse overjets of varying severity using the aesthetic component (AC) of the Index of Orthodontic Treatment Need (IOTN). Photographs of mild and severe AOB and reverse overjets were projected onto a white screen in a lecture theatre (15 seconds each with a 5 second interval between images). The participants were asked to record the AC grade at which they thought the projected picture of the AOB or reverse overjets had similar attractiveness. Dental awareness of non-dental students was determined by asking them their opinion on how important it was to have straight teeth (very unimportant, unimportant, important, very important), about their personal or close family members' orthodontic experiences and if they thought they were in need of any orthodontic treatment. A chi-square test was applied to record any differences between sexes and between the different groups. Backward stepwise linear regression analysis was used to determine the relationship between the students' ratings of the photographs and their dental awareness. The majority of non-dental students rated a mild AOB (93 per cent) and mild reverse overjet (96 per cent) to be aesthetically acceptable. A mild AOB and mild reverse overjet were found to be acceptable by 40 and 58 per cent of dental professionals, respectively. The differences in the ratings between dental professionals and non-dental students were significant at P < 0.001.A severe AOB was considered unattractive by both students and dental professionals. However, dental professionals rated it at the more unattractive end of the scale (P < 0.001). A severe reverse overjet was rated by the majority of the subjects as aesthetically unacceptable (85 per cent of the non-dental students and 78 per cent of the dental professionals).

Orthodontic treatment need and demand in 12-14-year-old north Jordanian school children.

This study was undertaken to assess the need and demand for orthodontic treatment among 12-14-year-old north Jordanian school children. In total, 1002 students randomly selected to represent five geographical areas of Irbid were examined. The examinations were carried out twice, first on the pupils in the school premises and then using study models taken from each student. The dental health (DHC) and aesthetic (AC) components of the Index of Orthodontic Treatment Need (IOTN) were used as an assessment measure of the need for orthodontic treatment. The demand for orthodontic treatment was measured by asking the students 'if it was necessary, would they like to have their teeth straightened by an orthodontist'. The results showed that approximately one-third (34 per cent) of the children examined had a definite need for orthodontic treatment. Within this group, 73.5 per cent were in need of orthodontic treatment according to the DHC, 23.5 per cent had both DHC and AC great need scores, and 3 per cent were in need according to the AC only. Severe contact point displacement of more than 4 mm was the most common occlusal feature in the definite treatment need group, followed by impeded eruption of teeth, hypoplasia of a single tooth and increased overjet of more than 6 mm but less than or equal to 9 mm. The demand for orthodontic treatment among the students was 49 per cent. Approximately half of them (54 per cent) had a definite need for orthodontic treatment. This study provides baseline data on the need and demand for orthodontic treatment among a Jordanian population, which is important for planning public orthodontic and dental services.

Evaluation of shear bond strength with different enamel pre-treatments.

The purpose of this study was to investigate the shear bond strengths of two adhesives, Panavia-21 and a composite resin (Transbond XT), with different enamel pre-treatments, acid etching (37 per cent phosphoric acid) and grit blasting (50 microm aluminium oxide particles). The mode of bond failure was also assessed using the modified adhesive remnant index (ARI). Ninety freshly extracted non-carious human premolar teeth were randomly divided into the following groups: (1) Transbond XT, acid-etched enamel surface; (2) Panavia-21, acid-etched enamel surface; (3) Transbond XT, grit-blasted enamel surface; (4) Panavia-21, grit-blasted enamel surface; (5) Transbond XT, acid-etched enamel surface with grit-blasted brackets; (6) Panavia-21, acid-etched enamel surface with grit-blasted brackets. All groups had stainless steel brackets bonded to the buccal surface of each tooth. An Instron universal testing machine was used to determine the shear bond strengths at a crosshead speed of 0.5 mm/second. Statistical analysis was undertaken using analysis of variance and the Tukey test. The mean bond strength values were as follows: group 1, 135.7 +/- 23.0 N; group 2, 181.5 +/- 18.4 N; group 3, 38.4 +/- 27.5 N; group 4, 59.1 +/- 24.1 N; group 5, 106.7 +/- 21.5 N; group 6, 165.3 +/- 21.4 N. Panavia-21 with the acid-etched enamel surface had a significantly higher shear bond strength than the other groups (P < 0.001). This was followed by the composite group with the acid-etched enamel surface. This group differed significantly from the composite and Panavia-21 groups with the grit-blasted tooth surface (P < 0.001) and from the composite and Panavia-21 groups with the acid-etched enamel surface and grit-blasted brackets (P < 0.01). The current findings indicate that Panavia-21 is an excellent adhesive and produces a bond strength that is clinically useful. Enamel surface preparation using grit blasting alone results in a significantly lower bond strength and should not be advocated for clinical use.

Growth prediction in Class III patients using cluster and discriminant function analysis.

This longitudinal retrospective cephalometric study was undertaken in an attempt to identify subgroups of subjects with Class III malocclusions and to find discriminant functions which would help to differentiate between favourable and unfavourable growers. The material consisted of cephalometric films of 115 Class III untreated patients (59 females and 56 males, with a mean age of 11.6 +/- 1.7 and 12.7 +/- 1.3 years, respectively) who were observed for a minimum period of 1 year. All subjects were Caucasian and none could achieve an edge to edge occlusion. Hierarchical cluster analysis was used to identify Class III subgroups. Discriminant function analysis (DFA) was first applied to the whole sample and later to each of the clusters produced. Good and poor growers were identified on the basis of the change in Wits measurements with projection on the maxillary/mandibular planes bisector. The cut-off point between good and bad growers was a Wits value of 2.5 mm which was the upper limit of the 95 per cent confidence interval of measurement reproducibility. Three clinically distinguishable clusters were produced, namely long, short and intermediate facial types. The discrimination percentage (80 per cent) achieved when the DFA was performed on the whole sample was satisfactory. However, when the analysis was used on each of the clusters separately, the equation successfully predicted a good or poor outcome in 92 per cent of cluster I, in 85 per cent of cluster II and in 100 per cent of cluster III.

Cephalometric measurements and facial deformities in subjects with beta-thalassaemia major.

This study was performed to identify cephalometric and facial features of patients with beta-thalassaemia major. A total of 54 thalassaemic subjects were examined for craniofacial deformities, including 37 patients (24 males and 13 females, aged 5-16 years) who had lateral cephalometric radiographs. The thalassaemic groups were compared with a normal control group matched for sex and dental age, using a t-test. All thalassaemic patients had a Class II skeletal base relationship. The average ANB angle was significantly larger than the controls in dental stages 2 and 3 (P < 0.05). Mandibular base length (Ar-Gn) was significantly less in thalassaemic patients than in controls, with the greatest differences (P < 0.001) found in the younger age group. The maxilla was of normal length (PNS-ANS, Ptm'-ANS') and appeared prominent (3.3 mm in males and 5.1 mm in females) due to a reduced cranial base length (Ar'-S') and a short mandible (Ar'-P'). Vertically, thalassaemic patients showed a significantly increased maxillary/mandibular planes angle in all groups, with differences ranging between 6.19 and 12.55 degrees (P < 0.001). Thalassaemic patients also showed a reduced posterior facial height (S-Go, Ar-Go) and increased anterior facial proportions. Of the 54 thalassaemic patients examined, 17 per cent had severe facial disfigurements (grade 3).

Uvulo-glosso-pharyngeal dimensions in subjects with beta-thalassaemia major.

The purpose of this study was to investigate cephalometrically the uvulo-glosso-pharyngeal dimensions in subjects with beta-thalassaemia major. The subjects were 15 thalassaemic patients (eight males, seven females) with a mean age of 14.13 +/- 1.06 years. The variables measured on the lateral cephalograms were tongue height and length, soft palate length and thickness, superior, middle and inferior pharyngeal airway space, and hyoid bone position. The thalassaemic group was compared with a normal control group matched for sex and age using a t-test. The results showed that thalassaemic patients had a smaller tongue size (length P < 0.05, height P < 0.001), shorter soft palate (P < 0.001), smaller upper (P < 0.001) and middle (P < 0.05) pharyngeal airway spaces, and a shorter vertical pharyngeal length (P < 0.05). The hyoid bone in thalassaemic patients was closer to the mandibular plane (P < 0.001).