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Objective: To compare the opinions of Swedish orthodontists and American orthodontists regarding the association between third molar eruption and dental crowding., Materials and Methods: A survey was distributed to Swedish orthodontists (n = 230) asking their views on the force exerted by erupting third molars, its relationship to crowding, and their recommendations for prophylactic removal. Results were compared with those from a similar study conducted in the United States. Chi square analysis was used to determine differences in responses to questions between Swedish and American orthodontists. P < or = .05 was considered significant., Results: Both Swedish and American orthodontists believed that lower third molars were more likely than upper third molars to cause force (65% and 58% for Swedish and American orthodontists, respectively) and crowding (42% and 40%, respectively). No statistically significant differences were seen between the answers of American and Swedish orthodontists regarding the role of upper and lower third molars in causing crowding. Although only 18% of Swedish orthodontists "generally" or "sometimes" recommended prophylactic removal of mandibular third molars, 36% of American orthodontists "generally" or "sometimes" recommended removal (P < .0001)., Conclusions: Most orthodontists in the United States and Sweden do believe that erupting lower third molars exert an anterior force; however, they also believe that these teeth "rarely" or "never" cause crowding of the dentition. The reason that more American orthodontists recommend prophylactic removal of mandibular third molars remains unexplained.

Objective: To determine whether lower lingual, canine to canine, bonded multistrand retainers prevent relapse of lower labial segment alignment following fixed appliance therapy and to compare this with lower Hawley-type removable retainers., Materials and Methods: Two groups of 29 patients were identified. Group 1 had bonded lower canine to canine multistrand retainers placed following debonding, whereas Group 2 had lower Hawley-type retainers (with acrylic labial to the incisors) fitted following debonding. Study models were taken of all patients at debonding (T(1)) and at least 1 year post debonding (T(2)). Changes in Little's index over the study period were recorded using a reflex microscope., Results: Statistically significant changes in Little's index occurred in the lower labial segment of both study groups (P = .001) over the observation period. There was no statistically significant difference in the amount of change in Little's index between the bonded and removable retainer groups (P = .13). Bonded retainers tended to be placed in older patients (P = .02)., Conclusions: Relapse can occur in the lower labial segment with both fixed and removable retainers. The amount of relapse seen with both types of retainer is not statistically significantly different.

Lip bumper treatment has been shown to successfully increase arch width, procline the incisors, and distalize molars. However, few studies have been performed showing the long-term stability of lip bumper treatment. In this study, mandibular casts taken by a single practitioner from 51 patients treated with lip bumpers without rapid palatal expansion were analyzed at pretreatment, post-lip bumper treatment, posttreatment, and long-term out of treatment. Measurements of arch width, arch depth, arch length, and anterior crowding were made. During treatment, there was a mean decrease in irregularity of 3.73 mm, with a posttreatment increase of 0.76 mm, for a net decrease of 2.97 mm. Despite posttreatment decreases, significant gains in arch width were maintained for extended periods of time. The intercanine width had a net increase of 1.78 mm (19% relapse), first premolars 3.39 mm (26% relapse), second premolars 2.58 mm (34% relapse), and first molars 2.17 mm (20% relapse). Lip bumper treatment along with fixed appliances is an effective means to obtain long-term increases in arch width and decreases in the irregularity index.

The prevalence of posterior crossbite among pacifier-sucking girls in Falköping, Sweden, was previously found to be 26%. The aim of this investigation was to follow the development of crossbites in pacifier suckers and to determinate the possibility of reducing the prevalence of crossbite by informing and instructing the parents about sucking habits and reducing the time the child has the pacifier in the mouth. Parents of 60 consecutively born girls belonging to St Olof's health district, Falköping, Sweden, were invited to take part in the study. All parents agreed to participate. Five interviews or examinations of each girl took place from birth until 3 years of age. Fifty-four (90%) of the 60 girls were breast-fed. The mean duration of breast-feeding was 8 months, and 67% of the girls were breast-fed for half a year or more. Forty-three children (72%) developed a pacifier-sucking habit, 6 (10%), a digit-sucking habit, and 11 (18%), no sucking habits. The mean duration of breast-feeding was longer for the nonsuckers (11 months) than for the pacifier- and digit-sucking children (5 months). Of the 39 girls who still had the pacifier habit at 3 years of age, 2 had developed a posterior crossbite. Another girl stopped the habit when a crossbite was registered at the 2 1/2-year examination. At the next appointment, the crossbite had corrected itself spontaneously. One of the 2 girls with crossbite at 3 years of age developed a prenormal occlusion with both anterior and posterior crossbites. For 12 more pacifier suckers, an interfering contact was noted with a forced guidance of the mandible and a midline shift. In all 12 cases, the interfering teeth were primary canines. We conclude that parents should be instructed to reduce the "in the mouth time" of the pacifier. The transverse occlusal relationship in pacifier-sucking children should be evaluated between 2 and 3 years of age. If interfering contacts of the primary canines exist, the parents should be instructed to reduce the pacifier-sucking time.

Forty consecutively referred children, 20 boys and 20 girls, with a Class II division I malocclusion and protrusive maxilla were treated with orthopedic cervical headgear with a 10 mm expanded inner bow and a long outer bow bent 15 degrees upwards. The mean age of the children at the beginning of treatment was 9.3 years (SD 1.3, range 6.6 to 12.4 years), and the average treatment time was 1.8 years (SD 0.6, range 0.8 to 3.1 years). In all patients Class II molar relationships were successfully corrected to Class I molar relationships. This was accompanied by a marked widening of both maxillary and mandibular dental arches. The cephalometric analysis suggested that the observed improvement of the occlusion was due to an inhibition of forward growth of the maxilla and anterior downward rotation of the palate.

Upper cuspid impaction is a serious problem that occurs with sufficient frequency to justify diagnosis and intervention as early as a dental age of 8 years. Screening consists of identifying patients who lack a normal cuspid bulge on palpation, with follow-up radiographic evaluation where indicated. Selective removal of deciduous cuspids is a suggested interceptive measure in Class I uncrowded malocclusions.