Anterior open bite malocclusion: a follow-up study of orthodontic treatment effects

Innovative Technique for Correction of Open Bite - A Case Report

Anterior open bite is defined as a condition in which upper incisor crowns fail to overlap the incisal third of the lower incisor crowns when the mandible is brought into full occlusion. The diagnosis, treatment, and successful retention of treated open-bite malocclusion continue to be a constant subject of discussion and study, contributing to the frustrations of clinicians. Various modalities have been used for the correction of open bite for the different age groups. In adult cases, an open bite can be corrected either by anterior extrusion or posterior intrusion, or a combination of both. Kim had described a method of using multiloop edgewise archwire for posterior intrusion. Here is a case report in which an innovative method is described which is a modification of Kim's method which is simpler, less time-consuming to place, hygienic, and they do not irritate the soft tissue. The bite closing mechanism and the treatment results are similar to Kim's method.

Root resorption followed by orthodontic treatment in individuals with anterior open bite. A complete vision focused on different treatment alternatives: A review

The aim of this review was to determine the incidence of different types of treatment and the prevalence of root resorption in incisors induced by orthodontic treatment in patients with open bite. Libraries and electronic databases were searched, with 322 articles being selected and 55 articles considered regarding PRISMA checklist. It has been shown that apical root resorption of the incisors is more frequent in patients with premolar extractions than in those treated without extractions, due to greater apical displacement during retraction of the anterior teeth in the space closure phase. On the other hand, it has been described that intrusion of posterior teeth is four times more likely to cause root resorption than extrusion movement, thereby increasing the risk of root resorption in posterior teeth compared to conventional orthodontic treatment not requiring molar intrusions. Finally, aligners, such as orthodontic treatments with fixed appliances, have not been shown to induce clinically significant root resorption in open bite individuals. Literature on root resorption in open bite treatments is scarce making difficult conclusions difficult. However, the amount of root loss in cases of open bite seems to be similar to that of individuals without open bite.

Nonsurgical correction of a Class III skeletal anterior open-bite malocclusion using multiple microscrew implants and digital profile prediction

A 20-year-old woman had a severe anterior skeletal open bite and a moderate skeletal Class III relationship with a prognathic mandible and a straight profile. She declined surgery. However, molar intrusion in a Class III patient with a straight profile can cause forward mandibular rotation and deterioration of the profile to a concave pattern. We used digital facial profile prediction software to determine whether the orthodontic compensation treatment would be acceptable to the patient. The final treatment plan consisted of extraction of the third molars, maxillary molar intrusion, and total distalization of the mandibular dentition with multiple microscrew implants. The patient cooperated with the use of Class III interarch elastics. The active treatment period was 20 months. Proper overbite and overjet, good occlusion, and an acceptable facial profile were achieved.

Evaluation of the Correlation of Ramus Height, Gonial Angle, and Dental Height with Different Facial Forms in Individuals with Deep Bite Disorders

BACKGROUND

Restoring the vertical dimension is a critical procedure in prosthetic dentistry. Anterior facial height has a significant impact on the length of the ramus. Patients with deep bite will exhibit a shorter lower facial height; hence, restoring the vertical dimension esthetically without altering the facial form is highly challenging.

AIM

To evaluate the relationship of gonial angle, ramus height, and dental height with different facial forms.

SUBJECTS AND METHODS

A total of 51 subjects in all facial form aged between 20 and 40 with deep bite were randomly selected. Lateral cephalograms and facial photographs were made for each patient. Ramus height was measured on lateral cephalogram by measuring the distance from articulare to gonion. The gonial angles were calculated and anterior and posterior dental height were measured from cephalogram. Facial forms were evaluated using patient's photographs.

RESULTS

The obtained measurements were evaluated, and compared statistically with one way analysis of variance and regression correlation test. Statistical analysis revealed that there was no correlation found between the gonial angle and ramus height.

CONCLUSION

Correlation found between the ramus height and anterior and posterior dental height in patients with deep bite disorders. The ramus height can be calculated using the formulas 46.42 + (0.095 × AD height), 46.046+ (0.123 × PD height).

Evaluation of the stability of open bite treatment using a removable appliance with palatal crib combined with high-pull chincup

OBJECTIVE: The aim of this prospective study was to cephalometrically analyze the stability of dentoalveolar and skeletal changes produced by a removable appliance with palatal crib associated to high-pull chincup in individuals with anterior open bite treated for 12 months, and compare them to individuals with similar malocclusion and age, not submitted to orthodontic treatment, also followed for the same period. METHODS: Nineteen children with a mean age of 9.78 years old treated for 12 months with a removable appliance with palatal crib associated with chincup therapy were evaluated after 15 months (post-treatment period) and compared with a control group of 19 subjects with mean age of 9.10 years with the same malocclusion that was followed-up for the same period. Seventy-six lateral cephalograms were evaluated at T1 (after correction) and T2 (follow-up) and cephalometric variables were analyzed by statistical tests. RESULTS: The results did not show significant skeletal, soft tissue or maxillary dentoalveolar changes. Overall, treatment effects on the experimental group were maintained at T2 evaluation with an increase of 0.56 mm in overbite. Overjet and maxillary incisors/molars position (vertical and sagittal) remained essentially unchanged during the study period. Only mandibular incisors showed significant changes (labial inclination and protrusion) compared to control group. CONCLUSIONS: Thus, it can be concluded that the early open bite treatment with a removable appliance and palatal crib associated with high-pull chincup therapy provided stability of 95%.

Má oclusão Classe I de Angle, com mordida aberta anterior, tratada com extração de dentes permanentes

A mordida aberta é uma anomalia com características distintas que, além da complexidade dos múltiplos fatores etiológicos, traz consequências estéticas e funcionais. Muitas alternativas têm sido utilizadas em seu tratamento, entre elas a grade palatina, forças ortopédicas, ajuste oclusal, camuflagem com ou sem exodontias, mini-implantes ou miniplacas e cirurgia ortognática. O diagnóstico preciso e a determinação da etiologia permitem estabelecer os objetivos e o plano de tratamento ideal para essa má oclusão. O presente relato descreve o tratamento de uma má oclusão Classe I de Angle, com padrão esquelético de Classe II e mordida aberta anterior, realizado em duas fases e que foi apresentado à diretoria do Board Brasileiro de Ortodontia e Ortopedia Facial (BBO), representando a categoria 2, como parte dos requisitos para a obtenção do título de Diplomado pelo BBO.

Compensation for vertical dysplasia and its clinical application

The purpose of this study was to quantitatively evaluate skeletal and dental compensation in patients with vertical skeletal dysplasias and to determine which dentoalveolar parameters compensate for vertical jaw discrepancies. Cephalometric analyses were performed on pre-treatment lateral cephalographs of 186 orthodontic patients (120 females and 66 males; mean age 15 years 11 months) who met the selection criteria. SN-MP angle was used to classify the facial patterns as: hyperdivergent > 36 degrees, normo = 28-36 degrees, and hypo < 28 degrees. Analysis of variance (ANOVA) was used to determine statistical differences between the means in the three vertical facial types. To evaluate dental compensation quantitatively, correlation analyses were performed to find associations between skeletal and dental parameters. To further elucidate the compensatory nature of the lower incisors, regression analyses and scattergrams were obtained, with SN-MP as a measure of the vertical skeletal discrepancy. ANOVA showed statistically significant differences for most of the skeletal variables, but only for lower incisor height and inclination among the dentoalveolar parameters. Correlation analyses demonstrated significant relationships between various skeletal variables. LI-MP showed a negative relationship with SN-MP, whereas LAMdH demonstrated a positive linear relationship with SN-MP. Among all dentoalveolar heights, UAMxH showed the weakest, and LAMdH the strongest, associations with skeletal parameters. The variability in dentoalveolar compensation therefore demands individualized diagnosis and treatment planning. LAMdH and LI-MP parameters were the most likely, whereas UAMxH was the least likely parameter to compensate for vertical dysplasia.

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.

Directional force treatment for an adult with Class III malocclusion and open bite

The orthodontic treatment of an adult patient with a Class III malocclusion and an anterior overbite is presented. Successful treatment required a differential diagnosis, specific planning, and careful control of the force systems to correct the disharmony in the vertical and horizontal dimensions. Fundamental to the successful treatment was the direction of the force applied to the teeth with a J-hook headgear. This directional force application made it possible to successfully correct the malocclusion without undesirable sequelae.

Dentoalveolar compensation in subjects with vertical skeletal dysplasia

INTRODUCTION

The purpose of this cephalometric study was to investigate vertical dentoalveolar compensation in untreated adults with excessive (long-face) and deficient (short-face) lower anterior face heights.

METHODS

Vertical and sagittal base relationships, vertical dentoalveolar dimension in the anterior region of the jaws, incisor inclination, overbite, and overjet were assessed in 112 short-face and 95 long-face subjects. The contribution of skeletal and dentoalveolar components to achieve a normal overbite was assessed by means of regression analysis. For the 2 most important independent variables of the regression equation, the values were calculated that would render an overbite of 2 mm. It was subsequently investigated whether the calculated value fell within the range of the sample.

RESULTS

In long-face subjects, overbite was mainly related to lower anterior face height; in short-face subjects, it was mainly related to mandibular anterior alveolar and basal heights. Dentoalveolar compensation occurred in both groups mainly by adaptations in mandibular incisor alveolar and basal heights. Molar height was unrelated to overbite. Cutoff values for achieving a positive overbite were calculated for lower face height and mandibular incisor alveolar and basal heights.

CONCLUSIONS

The lower face height mainly determines the overbite in long-face subjects, while in short-face subjects, lower dentoalveolar morphology influences overbite. Lower dentoalveolar compensation can maintain a normal overbite in long-face subjects to a limited extent.

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.

Stability of anterior open bite nonextraction treatment in the permanent dentition

This study cephalometrically evaluated the long-term stability of anterior open bite nonextraction treatment in the permanent dentition after a mean period of 5 years. The experimental group consisted of 21 patients who had undergone orthodontic treatment with fixed appliances from whom cephalometric headfilms were obtained at the pretreatment, posttreatment, and postretention stages. Two control groups were used. The first, with ages comparable with the experimental group before treatment, was used only to characterize it. The second control group, with normal occlusion, was longitudinally followed for a period comparable with the posttretention period and was used to compare the changes between groups during this period. The differences between the observation stages in the experimental group were analyzed with paired t tests, and the postretention changes were compared with the changes of the second control group with independent t tests. A statistically significant decrease of the obtained anterior overbite was demonstrated at the end of the postretention period. The primary factor that contributed to the overbite decrease was the smaller vertical development of the maxillary and mandibular incisors in the postretention period. Neither the pretreatment anterior open bite amount nor the magnitude of correction was associated with the long-term overbite decrease. However, 61.9% of the sample had a clinically stable open bite correction.

Comparison of the effects of passive posterior bite-blocks with different construction bites on the craniofacial and dentoalveolar structures

Posterior bite-blocks that are used in the early treatment of skeletal open bite, produce a forward and upward mandibular rotation by transmitting the masticatory muscle forces to the buccal dentoalveolar regions and preventing their vertical growth. Increasing the vertical dimension of the face artificially causes skeletal adaptations to occur not only in the dentoalveolar region but also in the other regions of the craniofacial complex. The affects of passive posterior bite-blocks, constructed in two different heights, were investigated for two treatment groups, in comparison to an untreated control group. Two treatment groups comprised of 25 growing patients, who had skeletal open bite and skeletal/dental Class I or Class II malocclusions, and one control group consisting of 14 growing patients were used. These groups were matched concerning their age, sex, and vertical and sagittal skeletal cephalometric and dental characteristics. Passive posterior bite-blocks of 5 and 10 mm heights were applied to the subjects of the treatment groups respectively for 18 hours per day. Untreated control subjects were observed for 7 to 9 months. The findings of this study revealed that the downward and backward mandibular rotation continued in the control group, increasing the lower facial height significantly, whereas in the treatment groups, the skeletal open bite was treated and the mandible rotated upward and forward. The increase of the height of the posterior bite-blocks had a significant effect on the anterior mandibular rotation and in the increase of the gonial angle.

[The course and results of the orthodontic treatment of 44 consecutively treated Class-II cases]

In this study treatment progress and treatment results of a consecutively treated group of 44 patients displaying a Class II malocclusion were evaluated in their relationship to the treatment goal. 41% of the patients had come to see the orthodontist on the advice of their family dentist but without any subjective problems as regards their tooth position. In 43% of the patients the treatment could not be finished in accordance with the treatment plan. In approximately 2/3 of these cases the reasons for the compromised results were due to patient cooperation problems. In the other 1/3 various types of treatment problems were encountered with loss of anchorage being the most typical. Over the entire treatment period patient cooperation was good in only approximately 50% of the cases. Oral hygiene was good in 27% of the patients at the first consultation appointment, but during the course of treatment this percentage increased to 64%. 85% of the patients expressed satisfaction with treatment results, but 34% of the patients did find the treatment to have been a burden. Enamel decalcifications were noticed in eleven patients. In another eleven patients root resorption of more than 2 mm of at least one upper incisor was noted.