Stability of anterior open bite nonextraction treatment in the permanent dentition

Three-year stability of open-bite correction by 1-piece maxillary osteotomy

INTRODUCTION

The purpose of this retrospective cephalometric study was to evaluate the long-term vertical stability of anterior open-bite correction by 1-piece Le Fort I osteotomy and rigid fixation.

METHODS

The sample comprised 40 consecutively treated patients from the files of the Department of Orthodontics, University of Oslo, Norway. All subjects had received a 1-piece Le Fort I osteotomy as the only surgical procedure from 1990 through 1998 and were followed for 3 years according to a protocol for data collection. Lateral cephalograms were obtained before surgery and at 5 occasions after surgery.

RESULTS

The mean open bite before surgery was 2.6 mm; at the 3-year follow-up, 35 patients had a positive overbite, and the remaining 5 patients had an open bite between 0.2 and 0.9 mm. Impaction of the posterior maxilla >or=2 mm relapsed on average by 31%, and inferior repositioning of the anterior maxilla >or=2 mm relapsed by 62%. Maxillary vertical skeletal changes during the postsurgery period were compensated for by orthodontic dentoalveolar adaptation. Most of the skeletal relapse occurred during the first 6 months after surgery and always in the direction opposite to the surgical movement. The relative contribution of mandibular and maxillary changes in anterior open-bite closure was approximately 3:1.

CONCLUSIONS

Surgical correction of anterior open bite was generally stable over a 3-year period, and skeletal relapse was counteracted by dentoalveolar compensation.

Anterior open bite with temporomandibular disorder treated with titanium screw anchorage: Evaluation of morphological and functional improvement

Skeletal anterior open bite is one of the most challenging malocclusions to correct because it is difficult to establish absolute anchorage for molar intrusion with traditional orthodontic mechanics. In addition, patients with anterior open bite sometimes have signs and symptoms of temporomandibular disorders (TMD). In this article, we report the successful treatment of a patient with severe skeletal anterior open bite and TMD; we used titanium screw anchorage. The patient, a woman, age 19 years 11 months, had an open bite of -4.0 mm and increased anterior lower facial height. The titanium screws were implanted in the mandible, and intrusion force was provided with elastic chains for 6 months. After active treatment for 36 months, her mandibular first molars were intruded about 3.0 mm, and good occlusion was achieved. Her retrognathic chin and convex profile were improved both by upward rotation of the mandible and advancement genioplasty with vertical reduction. After treatment, the TMD signs and symptoms were reduced, and improvements of both function and occlusion were achieved. Molar intrusion with titanium screw anchorage might be a useful treatment option to improve function, occlusion, and facial esthetics in patients with severe anterior open bite and TMD.

Long-term stability of orthodontic treatment and patient satisfaction. A systematic review

OBJECTIVE

To evaluate morphologic stability and patient satisfaction at least 5 years after orthodontic treatment.

MATERIALS AND METHODS

Published literature was searched through the PubMed and Cochrane Library electronic databases from 1966 to January 2005. The search was performed by an information specialist at the Swedish Council on Technology Assessment in Health Care. The inclusion criteria consisted of a follow-up period of at least 5 years postretention; randomized clinical trials, prospective or retrospective clinical controlled studies, and cohort studies; and orthodontic treatment including fixed or removable appliances, selective grinding, or extractions. Two reviewers extracted the data independently and also assessed the quality of the studies.

RESULTS

The search strategy resulted in 1004 abstracts or full-text articles, of which 38 met the inclusion criteria. Treatment of crowding resulted in successful dental alignment. However, the mandibular arch length and width gradually decreased, and crowding of the lower anterior teeth reoccurred postretention. This condition was unpredictable at the individual level (limited evidence). Treatment of Angle Class II division 1 malocclusion with Herbst appliance normalized the occlusion. Relapse occurred but could not be predicted at the individual level (limited evidence). The scientific evidence was insufficient for conclusions on treatment of cross-bite, Angle Class III, open bite, and various other malocclusions as well as on patient satisfaction in a long-term perspective.

CONCLUSIONS

This review has exposed the difficulties in drawing meaningful evidence-based conclusions often because of the inherent problems of retrospective and uncontrolled study design.

Long-term stability of an anterior open-bite malocclusion treated in the mixed dentition: a case report

A clinical case with anterior open-bite, treated in the mixed dentition, is presented. This approach demonstrates one of the possible approaches of treatment, which is capable of interfering with growth and redirecting its vectors. Orthodontic and orthopedic methods were used, consisting of slow maxillary expansion, through a fixed palatal crib soldered in a bi-helix appliance, and high-pull traction on the mandible for 16 hours a day. After eight years of follow-up, stable outcomes were accomplished. These results may be explained by the fact that treatments were performed at the appropriate period of development, thus establishing perioral muscular equilibrium, matching the final period of facial growth. The combination of orthodontic and orthopedic treatments was necessary to prevent the need of further orthognathic surgery treatment.

Cephalometric evaluation of anterior open-bite nonextraction treatment, using multiloop edgewise archwire therapy

There are very few reports of extensive and detailed cephalometric investigations of nonextraction treatment changes for patients with anterior open bite. The purpose of this study was to evaluate changes in dentomaxillofacial morphology by way of lateral and oblique cephalograms of patients who had undergone multiloop edgewise archwire (MEAW) therapy for anterior open-bite correction. The subjects consisted of 21 Japanese female patients who received MEAW therapy without premolar extraction. The mean pre- and posttreatment ages were 16 years 9 months and 19 years, respectively. Lateral and oblique cephalograms were taken before and after treatment. Fifteen angular and 29 linear measurements were obtained from the lateral cephalograms; 17 angular and 20 linear measurements were obtained from the oblique cephalograms. Treatment changes were evaluated by the paired t-test. The upward and forward rotational changes of the mandible consequent to the use of the MEAWs and anterior vertical elastics were larger than the downward and backward rotational changes of the mandible, due to the extrusion of the posterior teeth by leveling and alignment. The uprighting and retrusion of the premolars and molars, and the extrusion, uprighting, and/or retrusion of the incisors and canines played important roles in the anterior open-bite nonextraction treatment by dint of the MEAW technique.

Stability of anterior open-bite extraction and nonextraction treatment in the permanent dentition

INTRODUCTION

Although stability of anterior open-bite extraction and nonextraction treatment has been investigated, results suggesting that extraction treatment is more stable have not been confronted. Therefore, the purpose of this cephalometric study was to compare the long-term stability of anterior open-bite extraction and nonextraction treatment in the permanent dentition.

METHODS

Group 1 consisted of 21 patients treated without extractions, and group 2 included 31 patients treated with extractions who had orthodontic treatment with fixed appliances. Cephalometric headplates were obtained at pretreatment, posttreatment, and postretention. The groups were compared at these 3 times and during the treatment and posttreatment periods with independent t tests. The number of patients with a clinically significant relapse of the open bite was compared between the groups with chi-square tests.

RESULTS

During treatment, the maxillary incisors had greater retraction amounts, and the mandibular incisors had greater retraction and lingual tipping, and less extrusion in the extraction group. In the posttreatment period, the extraction group demonstrated statistically greater stability of the overbite. However, there was no statistically significant difference in the percentages of patients with clinically significant relapse of the open bite between the groups.

CONCLUSION

Open-bite extraction treatment has greater stability of the overbite than open-bite nonextraction treatment.

Mordida aberta anterior: uma fórmula para o diagnóstico diferencial

TEMA: diferenciar a mordida aberta anterior dental da mordida aberta anterior esquelética é necessário para que se estabeleça as metas e as condutas de tratamento ortodôntico e fonoaudiológico, tendo em vista que estas má oclusões têm etiologia e características morfofisiológicas distintas. OBJETIVO: estabelecer uma fórmula para o diagnóstico diferencial entre mordida aberta anterior dental e mordida aberta anterior esquelética, baseado na análise cefalométrica composta pelos ângulos que medem a inclinação do plano mandibular (NS.GoGn), a direção do crescimento mandibular no sentido vertical e ântero-posterior (NSGn), e a direção de crescimento mandibular e a posição vertical do mento (Eixo Facial). MÉTODO: 78 radiografias em norma lateral, de sujeitos com idade variando de 6 a 13 anos, foram analisadas e divididas em dois grupos - mordida aberta anterior dental e mordida aberta anterior esquelética. Resultado: Houve diferença significante entre os grupos quanto aos valores das medidas angulares, sendo que no grupo mordida aberta anterior esquelética as medidas dos ângulos NS.GoGn e NSGn foram maiores e do ângulo Eixo Facial menores em comparação ao grupo mordida aberta anterior dental. O ajuste dos dados à função linear resultou numa fórmula que permite definir o tipo de mordida aberta anterior a partir das referidas medidas angulares, com apenas 3,5% de margem de erro. CONCLUSÃO: foi possível estabelecer uma fórmula para o diagnóstico diferencial da mordida aberta anterior dental e mordida aberta anterior esquelética, o qual pode ser realizado com alto grau de confiança, a partir das medidas angulares NS.GoGn, NSGn e Eixo Facial. A fórmula estabelecida para o diagnóstico diferencial possui aplicabilidade em pesquisas e na clínica.

Assessment of open and incomplete bite correction by incisor overlap and optical density of polyvinyl siloxane bite registration

Open bite (OB) is a generalized term, which could incorporate subgroups that react differently to vertical correction. The objectives of the present study were to detect vertical treatment changes in incomplete bite (IB: inter-incisor overlap with no lower incisor contact with teeth or palate) and OB (no inter-incisor overlap) groups compared with a complete bite (CB: inter-incisor overlap with full lower incisor contact with teeth or palate) control group, to evaluate treatment response of the central and lateral incisors, and to study the vertico-sagittal interaction. Dental casts were taken at three time points, pre-treatment, post-treatment, and after one year of retention, from 54 Class II patients (22 males and 32 females with a mean age of 11 years 6 months) divided into three groups: CB (n = 21), IB (n = 18) and OB (n = 15). Measurements included incisor overlap (mm) and optical density (OD/mm2) of occlusal bite registration made of polyvinl siloxane. Both CB and IB groups demonstrated post-retention bite opening. However, bite opening in the CB group was three times greater than that in the IB group (e.g. lower lateral = -1.42 mm, 118 OD/mm2 versus -0.40 mm, 107 OD/mm2). Conversely, the OB group showed a significant (P < 0.001) bite closure (e.g. lower lateral = 1.30 mm, -377 OD/mm2). Overjet changes affected OD measurements, causing diversity in OD and millimetric measurements of the lateral incisors in the IB group. In conclusion, the OB group demonstrated a significant stable vertical correction; a post-treatment non-contact inter-incisor relationship was determined by a vertico-sagittal relapse; and full compensation of an IB was not possible.

Long-term stability of anterior open bite extraction treatment in the permanent dentition

The purpose of this study was to cephalometrically evaluate the long-term stability of anterior open bite extraction treatment in the permanent dentition after a mean period of 8.35 years. Cephalometric headfilms were obtained at pretreatment, posttreatment, and postretention stages from 31 patients who had undergone orthodontic treatment with fixed appliances. Two control groups were used. The first, with an age similar to that of the experimental group before treatment, was used only to characterize it. The second, with normal occlusion, was followed longitudinally for a period comparable with the posttreatment period and was used to compare changes during this period. The differences between the observation stages in the experimental group were analyzed with paired t tests, and the posttreatment changes were compared with the changes of the second control group with independent t tests. There was no statistically significant decrease of the obtained anterior overbite at the end of the posttreatment period. The primary factors that contributed to the nonsignificant decrease of the overbite were the normal vertical development of the maxillary and mandibular incisors, the smaller vertical development of the mandibular molars, and the consequent smaller increase in lower anterior face height, as compared with the control group in the long-term posttreatment period. Additionally, 74.2% of the sample had a "clinically stable" open bite correction.