Class II treatment in early mixed dentition with the eruption guidance appliance: effects and long-term stability.

OBJECTIVES: Our aim was to analyse dentoskeletal effects and long-term stability of Class II treatment carried out with an eruption guidance appliance (EGA) in early mixed dentition. MATERIALS AND METHODS: Sixty-five Class II patients (38 females and 27 males), treated with an EGA in early mixed dentition, were compared with 58 children (26 females and 32 males) with untreated Class II malocclusion. The mean age in the treatment group at the start (T1) and end of treatment (T2) was 5.4 years (±0.4) and 8.5 years (±0.9), respectively, and at the final examination in the early permanent dentition (T3) 16.7 years (±0.4). In the control group, the mean age at T1 and T2 were 5.1 years (±0.5) and 8.4 years (±0.5), respectively. The independent and dependent sample t-tests, Chi-square test, and Fisher's test were used in the statistical evaluation. RESULTS: In the treatment group, the frequency of Class II decreased from 100 to 14% during the treatment (T1-T2) and a significant correction took place in all occlusal variables. At T2, the treatment and control groups showed statistically significant differences (P < 0.05) in all occlusal variables. In the treated children, mandibular length increased 5 mm more (P < 0.001) from T1 to T2 compared to the control children, and the ANB angle became significantly smaller (P = 0.006). During the post-treatment period (T2-T3), the frequency of Class II in the treatment group decreased from 14 to 2% (P < 0.05), overbite increased from 2.2 to 3.1 mm (P < 0.05), and lower crowding increased from 2to 14% (P < 0.05). Post-treatment changes in overjet and upper crowding were not statistically significant. At T3, the mean values of the SNA, SNB, and ANB angles were 83.0° (SD 3.9°), 81.3° (SD 3.8°), and 2.4° (SD 1.5°), respectively. CONCLUSIONS: A clinically significant correction of the molar relationship, overjet, overbite, incisor alignment, and growth enhancement of the mandible were observed after treatment in early mixed dentition. The treatment results remained largely stable in the early permanent dentition. However, an increase was observed in overbite and lower crowding. None of the children treated in early mixed dentition needed a second treatment phase.

Stability of orthodontic treatment outcomes after 1-year treatment with the eruption guidance appliance in the early mixed dentition: A follow-up study.

OBJECTIVES: To investigate occlusal stability from the early mixed to the permanent dentition in children after early treatment with the eruption guidance appliance (EGA). MATERIALS AND METHODS: Of 46 participants who received 1-year early EGA treatment, 35 attended a follow-up examination at age 12. Group 1 (n = 21) started their EGA treatment at mean age 7.7 years, and group 2 at 9.1 years. Following 1-year treatment, the EGA was used as a retainer. Changes in overjet, overbite, sagittal molar relationship, and anterior crowding were measured on casts obtained before EGA treatment, after EGA treatment, and at follow-up to evaluate occlusal stability. RESULTS: Mean overjet, overbite, sagittal molar relation, and mandibular crowding improved significantly during the study period. Participants with good compliance during the retention period had significantly smaller overjet and overbite values than those with poor compliance. CONCLUSIONS: Early correction of increased overjet, overbite, and class II molar relation with the EGA is maintainable and can also be effective in the permanent dentition, provided the EGA is worn regularly as a retainer.

One year treatment effects of the eruption guidance appliance in 7- to 8-year-old children: a randomized clinical trial.

BACKGROUND: The eruption guidance appliance (EGA) aims to correct sagittal and vertical occlusal relations concomitantly with alignment of the incisors. Few reports have been published on treatment effects with the EGA but no randomized studies have been available. OBJECTIVES: The aim was to find out if 1 year active treatment time with EGA was sufficient for achieving normal occlusal relationships and dental alignment in 7- to 8-year-old children. PARTICIPANTS, STUDY DESIGN, AND METHODS: Eligibility criteria for participants were: fully erupted upper central incisors, and Angle's Class I or Class II molar relationship combined with any of the following traits: deep bite, increased overjet ≥5mm, moderate anterior crowding with overjet ≥4mm. After screening of 148 children, 48 7- to 8-year-old children were recruited in the study. The participants were randomly assigned into a treatment group (N = 25) and a control group (N = 23). Children in the treatment group received treatment with the EGA for 1 year. The controls had no orthodontic treatment. Changes in overjet, overbite, Angle's Class, and crowding were used as primary outcome measures. Occlusal assessments were performed on dental casts obtained from all subjects at start of the study (T1) and after 1 year (T2). Lateral cephalograms were obtained from all subjects at T1 and from the treatment group at T2. All measurements on dental casts and cephalograms were carried out blinded. RESULTS: Forty-six children completed the study. Mean overjet and overbite decreased significantly in the treated subjects during 1 year, in contrast to a slight increase in the controls. Class II molar relationship decreased from 46 to 4 per cent in the treatment group, with no significant change in the control group. Mandibular anterior crowding decreased significantly in the treated subjects, while the controls showed a slight increase. CONCLUSIONS: In short term, the EGA seems to be effective in correcting increased overjet and overbite, Class II malocclusion, and lower anterior crowding in the early mixed dentition. Follow-up data are needed to assess long-term effects of this treatment. REGISTRATION: This study was not registered.

Dentofacial changes after orthodontic intervention with eruption guidance appliance in the early mixed dentition.

OBJECTIVE: To evaluate skeletal and dentoalveolar changes induced by the eruption guidance appliance in the early mixed dentition. MATERIALS AND METHODS: Pre- and posttreatment cephalometric radiographs of 115 consecutively treated children, 62 boys and 53 girls, were compared with those obtained from a control group of 104 children, 52 boys and 52 girls. Pretreatment radiographs were taken at the deciduous-mixed dentition interphase (T1) and after full eruption of all permanent incisors and first molars (T2). The mean age of the children in both groups was 5.1 years at T1 and 8.4 years at T2. RESULTS: A significant difference between the groups at T2 was found in the mandibular length, midfacial length, and maxillomandibular differential. The increase in mandibular length was 11.1 mm in the treatment group and 7.2 mm in the control group. No differences were found in measurements of maxillary position or size. There was a significant shift toward a Class I relationship in the treatment group. Labial tipping and linear protrusion of the mandibular incisors was evident in the treatment group at T2. There was no effect on the inclination or position of the maxillary incisors. CONCLUSIONS: Occlusal correction was achieved mainly through changes in the dentoalveolar region of the mandible. In addition, the appliance enhanced condylar growth resulting in a clinically significant increase in mandibular length. No effect was observed on maxillary position, maxillary size, inclination or protrusion of the maxillary incisors, or facial height.

Orthodontic intervention in the early mixed dentition: a prospective, controlled study on the effects of the eruption guidance appliance.

INTRODUCTION: A prospective, controlled cohort study was started in 1998 to investigate the effects of orthodontic treatment in the early mixed dentition with the eruption guidance appliance. METHODS: Occlusal changes were recorded in 167 treated children and 104 controls after they had reached the middle mixed-dentition stage. Treatment began when the first deciduous incisor was exfoliated (T1) and ended when all permanent incisors and first molars were fully erupted (T2). The children's mean ages were 5.1 years (SD 0.5) at T1 and 8.4 years (SD 0.5) at T2. RESULTS: From T1 to T2, overjet in the treatment group decreased from 3.1 to 1.9 mm and overbite from 3.2 to 2.1 mm. In the control group, overjet increased from 2.9 to 4.1 mm and overbite from 3.3 to 4.1 mm. At T2, the differences between the groups were highly significant (P <.001). At T1, 18% of the children in the treatment group and 22% of the controls had tooth-to-tooth contact between the maxillary and mandibular incisors. All others had an open bite, or the mandibular incisors were in contact with the palatal gingiva. At T2, tooth-to-tooth contact was observed in 99% of the treated children and 24% of the controls (P <.001). Almost half of children in both groups showed incisor crowding at T1. Good alignment of the incisors was observed in 98% of the treated children at T2, whereas maxillary crowding was found in 32% and mandibular crowding in 47% of the controls (P <.001). At T1, 41% of the children in the treatment group and 53% of the controls had a Class I relationship; the rest had either a unilateral or a bilateral Class II relationship. At T2, a Class I relationship was found in 90% of the treated children and 48% of the controls (P <.001). At least 1 occlusal deviation, including overjet > or =5 mm, overbite > or =5 mm, open bite, gingival contact of the mandibular incisors, crowding, or Class II relationship, was observed in 13% of the treated children, but the deviations were mild, and no child was considered to need treatment. In the control group, 88% of the children showed at least 1 occlusal deviation (P <.001). CONCLUSIONS: Treatment in the early mixed dentition with the eruption guidance appliance is an effective method to restore normal occlusion and eliminate the need for further orthodontic treatment. Only a few spontaneous corrective changes can be expected without active intervention.

Dentofacial features of children with distal occlusions, large overjets, and deepbites in the early mixed dentition.

INTRODUCTION: The aim of this investigation was to analyze craniofacial morphology in children with distal bites, large overjets, and deepbites in the early mixed dentition. METHODS: The sample comprised 486 Finnish children who are participating in an ongoing clinical trial. Cephalograms were obtained at the deciduous-mixed dentition interphase for the baseline of the trial. The mean age of the children was 5.1 years (SD, 2.6; range, 4.0-7.8 years). RESULTS: Subjects with bilateral distal steps of > or =1 mm compared with normal had long midfaces (P <.05), short and retrusive mandibles (P <.05), small maxillomandibular differentials (P <.001), convex profiles (P <.01), retrusive mandibular incisors (P <.01), and large interincisal angles (P <.001). Children with overjets of > or =4 mm had retrusive mandibles (P <.001), long maxillae and midfaces (P <.001), small maxillomandibular differentials (P <.001), convex profiles (P <.001), and protrusive maxillary and retrusive mandibular incisors (P <.001). Children with deepbites (overbites of > or =4 mm) had short and retrusive mandibles (P <.05), long midfaces (P <.001) and maxillae (P <.05), small maxillomandibular differentials (P <.001), convex profiles (P <.01), retrusive mandibular incisors (P <.001), and large interincisal angles (P <.001). No differences were found in the length of anterior cranial base, the position of maxilla relative to cranial base, lower facial height, and facial axis angle between any malocclusion group and normal children. All correlations between the occlusal and skeletal characteristics were low, suggesting only weak associations at this stage of development. CONCLUSIONS: These results indicate that the early dentofacial features of children with distal occlusions, large overjets, and deepbites differ from normal values. However, the skeletal patterns of these 3 malocclusion types showed considerable similarities, with long but neutrally positioned maxillae, retrusive mandibles, small maxillomandibular differences, convex profiles, retrusive mandibular incisors, and large interincisal angles, but normal growth directions and lower facial heights as common features.

Feasibility and long-term stability of surgically assisted rapid maxillary expansion with lateral osteotomy.

Surgically assisted rapid maxillary expansion (SARME) has become a widely used and acceptable means to expand the maxilla in adolescents and adult patients. The method takes advantage of bone formation at the maxillary edges of the midline, while they are separated by an external force. The purpose of the present retrospective investigation was to evaluate the feasibility and long-term stability of maxillary expansion in patients in whom lateral pre-expansion osteotomy had been performed. The subjects were 20 patients (14 females, six males, mean age 30.6 years, range 16.2-44.2 years) whose malocclusions were treated solely or partly with SARME during 1988-1996. Two orthodontists carried out the post-orthodontic expansion treatment. The surgical technique followed a minimally invasive osteotomy on the lateral maxillary walls. Study models were obtained before surgery (T1), once expansion and the following orthodontic treatment were completed, before possible second-stage osteotomy (T2), and at long-term follow-up (T3). Using the study models, the width of the dental arch was measured with a digital sliding calliper. In addition, transverse occlusal relationships were examined at each time point. The results indicated that (1) SARME is possible when the minimally invasive operation technique is used, (2) long-term stability of maxillary expansion following the present technique compares favourably with the widening and stability achieved with other, more invasive, osteotomies. With age, several possible uncertainties are introduced to affect the course of SARME adversely. Therefore, more extensive osteotomies can be recommended in older patients.

Occurrence of malocclusion and need of orthodontic treatment in early mixed dentition.

This study analyzed the occlusions of 489 children at the onset of the mixed dentition period (mean age 5.1 years, range 4.0-7.8 years). These children participate in an ongoing clinical trial that is investigating the effects of orthodontic intervention in the early mixed dentition. The aim was to report the occlusal findings at the baseline. The frequencies of mesial step, flush terminal plane, and distal step were 19.1%, 47.8%, and 33.1%, respectively. The canine relationship was Class I in 46.1%, Class II in 52.4%, and Class III in 1.5% of the sides examined. An asymmetrical canine relationship was found in 30.1% of the children, significantly more often on the right side than on the left (P <.001). Overjet ranged from -2 to +10 mm with a mean of 2.9 mm. Overbite ranged from -5 to +8 mm with a mean of 2.8 mm. Excessive (> or =4 mm) overjet was found in 26.7% and overbite in 33.8% of the children; in 15.5% of the children, both variables were 4 mm or more. Anterior crowding was detected in the maxillary arch in 11.6% and in the mandibular arch in 38.9% of the children. Girls showed mandibular crowding more often than boys (P <.01). A posterior crossbite was found in 7.5% of the children, unilaterally in 6.4% and bilaterally in 1.1%. Scissors-bite was detected in 1.1% and an anterior crossbite in 2.2% of the children. The mean maximal opening was 40.3 mm. Joint sounds were registered in 5.2% of the children. The prevalence of malocclusion was between 67.7% and 92.7%, depending on the values of unacceptable parameters used for each occlusal characteristic.

Costs of surgical-orthodontic treatment in community hospital care: an analysis of the different phases of treatment.

To determine the distribution of costs and various influencing factors in the entire process of surgical-orthodontic treatment in community hospital care, a retrospective study was carried out. The records and radiographs of 99 community hospital patients operated on between 1994 and 2001 were included. Cost analysis data were gathered from 4 phases of treatment: the orthodontics, the surgical outpatient assessments, the surgery/surgeries, and the inpatient period. The results showed that the surgical phases together are responsible for roughly 61% of the costs, 28% of which were attributed to the surgical operation itself. Orthodontics made up approximately 39% of the total costs, with an average of 26 visits. The average total costs of all treatments were US $6,206 +/- 912. Patients that could be operated on with bilateral sagittal split ramus osteotomy of the mandible only had the lowest costs, and those who required bimaxillary osteotomies had the highest costs. Of the several clinical and cephalometric measurements made in this study, only skeletal open bite and orthodontic space closure after tooth extraction were found to affect the costs. It can be concluded that surgical-orthodontic treatment is a rather expensive way to correct dentofacial malocclusions due to the high costs of the surgical phase. Skeletal open bite constituted the most costly entity, while malocclusion resulting from mandibular deformity was the cheapest.