Twelve orthodontic patients undergoing treatment with fixed appliances took part in the present study. In all patients elastomeric rings were used for ligation on one side of the dental arch midline, whereas steel wires were used on the opposite side. The number of micro-organisms in samples of plaque, taken from the labial surface of the upper lateral incisors, was recorded on five occasions during treatment. In samples of saliva, the numbers of Streptococcus mutans and lactobacilli were recorded on the same occasions. This registration was also made on two occasions before insertion of the fixed appliance, and 6 weeks after the period of active treatment. The results showed that, in the majority of patients, the incisor which was attached to the arch-wire with an elastomeric ring, exhibited a greater number of micro-organisms in the plaque than the incisor ligated with steel wire. Following insertion of fixed appliances the number of S. mutans and lactobacilli in saliva increased significantly. Variations in the number of micro-organisms in the saliva during active treatment were not reflected in any relative increase or decrease in microbial colonization on either steel ligatures or elastomeric rings. The use of retainers after active treatment was not associated with increased numbers of micro-organisms in the saliva.

A radiographic dental examination was performed in 16 children conditioned with total body irradiation (TBI) and cyclophosphamide (CY) prior to bone marrow transplantation (BMT), and in 52 children treated with multiagent chemotherapy. For each child, three age- and sex-matched healthy controls were selected. Evaluation of disturbances in dental development and tooth size was based on planimetric measurements of mandibular teeth on panoramic radiographs. Short V-shaped roots were diagnosed in 94 per cent of the children treated with TBI/CY compared with 19 per cent in the chemotherapy group (P < 0.001). Children receiving TBI/CY also exhibited a pronounced reduction in tooth size compared with the controls. Reductions varied from 19 per cent in incisors to 39 per cent in the second molars. In the chemotherapy group the corresponding values were 7 and 15 per cent respectively. When comparing crown/root ratios, the indices for incisors, canines (P < 0.05) and molars (P < 0.01) in the BMT group were significantly higher than the corresponding values in the control group. This indicates that the reduction in root size was more pronounced than the reduction in crown size. The premolars in the BMT group exhibited a similar reduction in crown and root size. All developing teeth were affected by multiagent chemotherapy and radiation therapy. The most severe disturbances were found in children treated with TBI/CY at a young age.

A longitudinal roentgen cephalometric investigation of vertical craniofacial and dentoalveolar changes during 20 years of adulthood, was performed in 15 men and 15 women. Two lateral cephalograms taken at the average ages 25 and 45 years, were available of each subject. Skeletal and dental changes were described by 13 linear and four angular cephalometric measurements. The analysis of the linear variables showed that total anterior face height increased by 1.60 mm on average. Approximately one-fifth of this increase occurred in the upper and four-fifths in the lower face. In the dentoalveolar region, significant increments of all dimensions except overjet and overbite were found, indicating an eruptive movement of the teeth and a vertical development of their investing tissues. The analysis of the angular measurements showed that posterior rotation of the mandible and uprighting of the upper incisors had occurred during the period of investigation.

The aim of this study was to compare a number of dentofacial variables and airway space in children suffering from obstructive sleep apnoea (OSA) syndrome with the corresponding variables in control children exhibiting a normal breathing pattern, to study the development of these variables prospectively over a 5-year-period following treatment for OSA, and to compare the recorded changes with the corresponding changes occurring in the controls. The subjects were 17 children (10 boys and 7 girls, mean age 5.6 years) diagnosed with OSA syndrome. The treatment for the OSA was adeno-/tonsillectomy. The control group comprised 17 age- and gender-matched children (mean age 5.8 years) without breathing problems. Lateral cephalograms were taken of the OSA children at baseline and then at 1, 3, and 5 years post-treatment. The control records comprised registrations at baseline and then after 1 and 5 years. In comparison with the controls, the OSA children exhibited a more posteriorly inclined mandible (P < 0.05), a more anteriorly inclined maxilla (P < 0.001), a greater lower anterior face height (P < 0.01), a shorter anterior cranial base (P < 0.01), retroclined upper and lower incisors (P < 0.05 and P < 0.01, respectively), reduced airway space (P < 0.05 and P < 0.01), and a less pronounced nose (P < 0.05). At 5 years post-treatment, there were no statistically significant differences between the groups except for the lengths of the anterior cranial base and the nose which were still shorter (P < 0.05) in the patient group. OSA in young children has an unfavourable effect on the development of several dental and facial components. However, if OSA is diagnosed and treated at an early age, an almost complete normalization of dentofacial morphology may be achieved.

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SUMMARY The purpose of this study was to investigate craniofacial morphology in obese adolescents and to compare the morphological data with those of normal adolescents.The study was based on measurements of lateral cephalometric roentgenograms of adolescents who had been diagnosed as obese. Linear and angular measurements were obtained from cephalometric tracings of 27 females (mean age 15.6 ± 0.83 years) and 23 males (mean age 13.9 ± 0.98 years). The data were compared with corresponding measurements of gender and age matched controls.The results showed that both males and females in the obesity group exhibited signifi cantly larger mandibular and maxillary dimensions than the controls. On average, mandibular length (Cd-Pgn) was 10 mm greater in males and 8 mm greater in females. Maxillary length (Pm-A) was 3.5 mm greater in males and 3 mm greater in females. When considering vertical dimensions, lower anterior (Ans-Gn) and posterior (S-Go) face height were 4 and 5 mm greater in the obese males, respectively, while in the obese females both these distances were 4 mm greater compared with the controls. Both maxillary (SNA) and mandibular (SNB, SNPg) prognathism were more pronounced in the obesity group than in the control group. This also infl uenced the average soft tissue profi le, which was less convex in the obesity groups. The mandibular plane angle (ML/SN) was smaller in the obesity group than in the control group.Craniofacial morphology differs between obese and normal adolescents. In general, obesity was associated with bimaxillary prognathism and relatively greater facial measurements.