Anterior Open Bite Malocclusion Research Articles

Initial intrusion of the molars in the treatment of anterior open bite malocclusions in growing patients.

The treatment of the hyperdivergent phenotype and/or anterior openbite is one of the common problems facing orthodontists. The purpose of this study is to present a new appliance (Molar Intruder) for molar intrusion and to determine its effects in the treatment of anterior openbite. The study group comprised 14 patients (eight girls and six boys), with a mean age of 10 years and 7 months. All presented anterior open bite malocclusions between the second premolars. The study was carried out on lateral head films taken before (T1) and after (T2) molar intrusion. Periapical radiographs, study models, and standard photographs of all the patients were also obtained before and after molar intrusion. The paired sample t-test was used to determine the differences between the parameters. The average treatment time with the Molar Intruder was five months. The mean intrusion of maxillary and mandibular molars was 1.86 mm and 1.04 mm, respectively. Maxillary incisors extruded 0.54 mm with a labial tipping of 1.46 degrees and overbite increased by 4.00 mm. The mandibular plane angle was decreased by 1.57 degrees, and the anterior face height was decreased by 1.86 mm on average. The mandible showed a counterclockwise rotation, the chin moved forward, and the posterior facial height/anterior facial height ratio was increased. Anterior openbites of the patients were significantly rehabilitated at the end of the intrusion period, simplifying further orthodontic treatment.

Skeletal and dental effects during observation and treatment with a magnetic device.

The aim of this study was to evaluate the effects of a magnetic appliance, MAD IV, on the treatment of anterior open bites in growing patients. The study material included the lateral cephalograms and hand-wrist radiographs of 16 patients who had an anterior open bite malocclusion. The radiographs were taken at the beginning (T1) and at the end of observation period (T2) and at the end of MAD IV application (T3). At the beginning of the study, the mean age of the subjects was 11 years two months. To define the direction of facial growth, the patients were first observed for nine months without any orthodontic or orthopedic approach. At the end of the observation period, patients who had shown a vertical growth direction, resulting in an increase in open bite, were given an MAD IV appliance and were instructed to wear the appliance 18 hours a day for 7.5 months. Thirty-two different parameters were evaluated from the lateral cephalograms. Paired t-tests were used for statistical evaluation of differences that occurred during the periods and between the periods. During the observation period, the patients continued their mandibular posterior rotation resulting in an increase in lower facial height (P < .001) and an open bite (P < .01). During the treatment period, the patients showed an anterior mandibular rotation with statistically important decreases in lower facial height and open bite (P < .001). In the treatment of anterior open bite with the MAD IV appliance, skeletal changes played a role along with dental and dentoalveolar effects.

Closing anterior open bites by intruding molars with titanium miniplate anchorage

The intent of this study was threefold: (1) to validate true intrusion of molars in adults, (2) to test the stability of miniplates as anchorage for intruding posterior teeth in the maxilla, and (3) to record the skeletal and dental changes of open-bite closure. Four adult patients who had anterior open-bite malocclusions were selected to undergo posterior intrusion with miniplate anchorage to close the open bite; all had true intrusion of the maxillary molars. Mean molar intrusion was 1.99 mm (range, 1.45-3.32 mm). No movement of miniplates occurred at any time during their use or before intentional clinical removal. Open-bite closure was achieved for all 4 patients. Mean closure of incisors was 3.62 mm (range, 3.0-4.5 mm) as the mandibular plane closed 2.62° (range, 1.5°-4.5°), and the occlusal plane decreased 2.25° (range, 1.0°-3.5°). Anterior facial heights decreased as the mandible closed and B-point rotated anteriorly and upward. (Am J Orthod Dentofacial Orthop 2002;122:593-600)

Stability of open bite treatment

Am J Orthod Dentofacial Orthop 2002;121:566-8

Anterior open-bite malocclusion: stability of maxillary repositioning using rigid internal fixation

Abstract A retrospective cephalometric study was performed to investigate the stability of 37 non-growing anterior open-bite cases using mini-plate rigid fixation. The sample was divided into two groups: Group A: maxillary repositioning alone (17 cases) and Group B: bimaxillary surgery (20 cases). Tracings were performed pre-operatively (T1), immediately post-operatively (T2) and at a minimum of one year follow-up (T3) (12–90 months). In Group A, the maxilla was advanced (3.8 +_ 2.8 mm, p &lt; 0.01) and superiorly repositioned at PNS (2.8 +_2.3 mm, p &lt; 0.001). In Group B, the maxilla was advanced (3.5 +_ 3.0 mm, p &lt; 0.01) and superiorly repositioned at PNS (3.7 +_ 1.8 mm, p &lt;0.001); and the mandible (11.7 +_ 3.8 mm, p &lt; 0.001), with no significant change in the vertical plane (p &gt; 0.05). Late relapse due to condylar remodelling or resorption was found as a cause of large horizontal relapse (8.0 &lt; x &lt; 14.0 mm) in three cases (15%), the amount being associated with the amount of operative advancement (r = 0.7, r-sq = 40%, p &lt; 0.01). It was concluded that the correction of anterior open bite by posterior repositioning of the maxilla using rigid fixation is a stable procedure during the follow-up period, and that in bimaxillary cases, post-operative stability depends largely on the stability of the mandibular advancement, which in turn relates to the amounts of advancement, the pre-operative anterior open bite and the mandibular plane angle.

Stability of anterior openbite correction with multiloop edgewise archwire therapy: A cephalometric follow-up study

Successful treatment of anterior openbite malocclusion is considered one of the most challenging areas in orthodontics. This study was designed to evaluate the treatment effects of the multiloop edgewise archwire therapy in openbite correction and to investigate the stability of correction during a 2-year follow-up period. The subjects consisted of 55 white patients who presented with anterior openbite. The subjects were divided into 2 groups: the growing group included 29 patients and the nongrowing group included 26 patients. The lateral cephalograms were analyzed for skeletal, esthetic, and dentoalveolar changes. Analysis of the pretreatment and posttreatment cephalometric radiographs revealed that the overbite increased an average of 4 mm in both the growing and the nongrowing groups. Analysis of the posttreatment and follow-up cephalometric radiographs proved that the treatment results obtained by this therapy were very stable. The changes in overbite during the 2-year follow-up period were not significant. (Am J Orthod Dentofacial Orthop 2000;118:43-54)

Cephalometric evaluation of the anterior open bite treatment

The present study was aimed at evaluating the treatment changes of anterior open bite malocclusion cases treated by means of the Multiloop Edgewise Arch Wire technique, which is considered one of the more effective treatment modalities for anterior open bite malocclusions. The open bite sample was composed of 16 young adults, 4 males and 12 females. The normal occlusion sample, as a controlled sample was composed of 58 young adults who had pleasing facial profiles and normal occlusions with no experience of orthodontic or prosthodontic treatment. The normal sample was subdivided by the cephalometric vertical facial relationships. Forty adults with cephalometric vertical facial relationships within the normal range of Korean standards were classified as Normal Occlusion Group 1. Eighteen adults with an increased vertical facial relationship but with normal occlusion, were classified as Normal Occlusion Group 2. Thirty-nine reference points were digitized on each film, and the computerized cephalometric analysis was obtained with 8 skeletal, 10 dentoalveolar, 17 teeth angulations, and 4 occlusal plane measurements. Treatment changes were determined by the paired t test, and the structural differences between the four groups were tabulated by the Student’s t test. The treatment changes were observed mainly in the dentoalveolar region in the upper and the lower occlusal planes, accompanied by the uprighting of the posterior teeth to the occlusal plane through the distal tipping movement of the entire dentition. After the treatment, there was a tendency for the structural feature of the open bite group to approximate those of the normal occlusion group 2. This ascertains that the treatment changes of open bite malocclusion produced by means of the multiloop edgewise arch wire technique are similar to those found in the natural dentoalveolar compensatory mechanism. (Am J Orthod Dentofacial Orthop 1999;115:29-38)

Treatment of an adult with a severe anterior open bite and mutilated malocclusion without orthognathic surgery

A case report of a 19-year, 7-month-old young woman who had an Angle Class I mutilated malocclusion, characterized by a skeletal/dental anterior open bite, crowding, thumb-sucking habit, and bimaxillary dental protrusion is presented. A nonsurgical approach was used to obtain significant improvement in occlusion and in facial esthetics. [This case report was presented to the American Board of Orthodontics in partial fulfillment of the requirements for the certification process conducted by the Board.]

The effects of Frankel's function regulator (FR-4) therapy on the treatment of Angle Class I skeletal anterior open bite malocclusion

The present study attempts to evaluate cephalometrically the effects of Fränkel's function regulator (FR-4) appliance on the treatment of Angle Class I skeletal anterior open bite malocclusion. Forty Turkish children (26 girls and 14 boys), with Angle Class I skeletal anterior open bite, were randomly divided into two groups of 20 (13 girls and 7 boys). Patients who had not undergone treatment served as the control group, whereas a second group was treated with lip-seal training and the FR-4 appliance. Chronologic mean decimal age at initial period of the investigation was 8.7 years in the treated group, and 8.9 years in the control group. Treatment and observation periods were 2 years. Investigation was carried out on lateral cephalograms taken before and after the study period. The results indicate that a spontaneous downward and backward growth direction of the mandible observed in the control group could be changed to a upward and forward direction by FR-4 therapy. The skeletal anterior open bite was successfully corrected through upward and forward mandibular rotation. (A M J O RTHOD D ENTOFAC O RTHOP 1995;108:9-21.)

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

Treatment response and stability of the anterior open bite malocclusion were evaluated in 20 open bite patients (17 females, 3 males), who were treated with the Edgewise appliance. The overbite, the number of teeth in occlusion, the functional occlusal contacts of the incisors and the cephalometric characteristics were studied before treatment (T1), at the end of retention (T2), and at least 1 year out of retention (T3). The apical root resorption of the upper incisors was analysed before and after treatment. The mean age at the follow-up control was 17 years 10 months. In 15 patients at least two occlusal contacts of the incisors were possible at the end of the retention period as well as at the follow-up control. The number of teeth in occlusion mesial to the second molars, expressed in percentage of the maximum possible, increased from 40 to 70 per cent during treatment with a positive tendency from T2 to T3. Apical root resorption of the upper incisors exceeded 10 per cent of the original root length in 4 out of 19 measurable cases. One of these patients had a history of trauma and the three others displayed atypical root form. Cases with an increased facial convexity, in which the uprighting of the incisors was possible, seemed to have a favourable treatment prognosis.

Dentoskeletal and Tongue Soft-Tissue Correlates: A Cephalometric Analysis of Rest Position

The relationship between dentoskeletal and tongue soft-tissue variables has been quantified in a sample of 60 adult females with normal and anterior open-bite malocclusions. Three lateral rest-position head films were obtained for each subject. A principal component analysis reduced the data base and six significant canonical correlations were identified. The first canonical correlation (r, = 0.962) represented a size-related correlation factor between the two groups of variables. Subjects with characteristics of a short face syndrome and some evidence of overbite had tongue tips positioned below the lower occlusal plane (r2 = 0.929). In contrast, skeletal open-bite subjects (r. = 0.759) revealed tongue tips ahead of and above the lower incisor teeth with the mandible in the rest position. Undererupted mandibular teeth (r5 = 0.666) were associated with a reduced tongue height and an inferior epiglottis; short tongue length (r6 = 0.563) correlated with a linear combination of upright central incisors, a small overjet, a low ANS angle, unerupted maxillary and mandibular teeth, and a steep occlusal plane. The multivariate statistical analysis extracted clinically significant associations between tongue soft-tissue and dentoskeletal variables. Tongue posture at rest in skeletal open-bite subjects appeared to be related to incisor position. (AM J ORTHOD 88: 333-341, 1985.)

Dentoskeletal and tongue soft-tissue correlates: A cephalometric analysis of rest position

The relationship between dentoskeletal and tongue soft-tissue variables has been quantified in a sample of 60 adult females with normal and anterior open-bite malocclusions. Three lateral rest-position head films were obtained for each subject. A principal component analysis reduced the data base and six significant canonical correlations were identified. The first canonical correlation (r 1 = 0.962) represented a size-related correlation factor between the two groups of variables. Subjects with characteristics of a short face syndrome and some evidence of overbite had tongue tips positioned below the lower occlusal plane (r 2 = 0.929). In contrast, skeletal open-bite subjects (r 4 = 0.759) revealed tongue tips ahead of and above the lower incisor teeth with the mandible in the rest position. Undererupted mandibular teeth (r 5 = 0.666) were associated with a reduced tongue height and an inferior epiglottis; short tongue length (r 6 = 0.563) correlated with a linear combination of upright central incisors, a small overjet, a low ANB angle, unerupted maxillary and mandibular teeth, and a steep occlusal plane. The multivariate statistical analysis extracted clinically significant associations between tongue soft-tissue and dentoskeletal variables. Tongue posture at rest in skeletal open-bite subjects appeared to be related to incisor position.

Anterior open-bite malocclusion: A longitudinal 10-year postretention evaluation of orthodontically treated patients

Long-term response of the anterior open-bite malocclusion was evaluated in forty-one white subjects who had undergone orthodontic treatment and were out of retention a minimum of 9 years 6 months. The purpose of the study was threefold: (1) to make cephalometric comparisons between a sample of open-bite patients and a sample with normal cephalometric standards, (2) to evaluate treatment and posttreatment changes that occurred in treated open-bite patients, and (3) to search for predictors and associations of value. Changes occurring across time in the open-bite patients were analyzed by computer means using pretreatment, posttreatment, and long-term cephalometric radiographs and dental casts. An analysis of subgroups was reviewed to compare dentoalveolar and skeletal relationships of both stable and relapse groups. More than 35% of the treated open-bite patients demonstrated a postretention open bite of 3 mm or more, with the relapse subgroup demonstrating across-time, less mandibular anterior dental height, less upper anterior facial height, greater lower anterior facial height, and less posterior facial height. Neither the magnitude of pretreatment open bite, mandibular plane angle, nor any other single parameter of dentofacial form proved to be a reliable predictor of posttreatment stability.

Tongue and jaw muscle activity in response to mandibular rotations in a sample of normal and anterior open-bite subjects

In order to investigate the effect of mandibular rotations in human subjects, the electromyographic activity from the left GG, left masseter, and left orbicularis oris muscles was recorded during voluntary opening movements of the mandible that were monitored by an electronic transducer. For each muscle, a computer-based system was used to calculate a threshold incisor-separation position corresponding to a 20 percent increase in base line muscle activity. The mean threshold level for the GG muscle in a sample of twenty subjects with normal occlusions was 53.0 percent (S.D. ± 22.8) of maximum jaw opening. By contrast, a sample of nine subjects with anterior open-bite malocclusions had a statistically significant (p < 0.001) lower mean threshold of 5.9 percent (S.D. ± 4.5) of maximum jaw opening. No significant differences in masseter or orbicularis oris muscle activity were found between the two samples. Since postural tongue activity could play an important role in the development of the anterior dentition, the lower threshold for the GG muscle activity in response to jaw opening in anterior open-bite subjects may be of significant clinical importance.

A Review of Anterior Open Bite

Anterior open bite malocclusion is reviewed under the headings of aetiology, morphology and treatment. The aetiology is discussed within the classification originally described by Dockrell in 1952. The morphological differences between skeletal and dental open bite together with the extra oral, intra oral, and cephalometric characteristics are described. Recognition is given to the recent developments in maxillo facial surgery and the importance of a combined surgical and orthodontic approach to the treatment of skeletal open bite. The merits of the palatal crib either on a fixed or removable appliance to break a thumb sucking habit are discussed in relation to the dental open bite. The relationship of post treatment stability to the adequate removal or modification of the aetiological factor is stressed.

Anterior open-bite: A cephalometric analysis and suggested treatment procedures

0 n e of the most difficult aspects of diagnosis lies in making a decision regarding the nature of the condition or syndrome under consideration. This conceptual difficulty is illustrated by some recent articles on the subject of anterior open-bite. I, 2 In these reports, “open-bite” is considered an adequate definition of the condition, and little consideration is given to the fact that this term includes several skeletal variants that all have in common a ?zegative incisal overbite.3 The purpose of this essay is to present a cephalometric assessment of various types of anterior open-bite malocclusion and to review some concepts that may help in understanding the limitations in the treatment of such patients. Many of these concepts are not new and have been ably presented by Hellman Subtelny and associates,5* 6 and Horowitz and Hixon.7 It should be emphasized that cephalometrics, at best, is a descriptive technique which helps to define or classify a condition but does not necessarily provide us with the insight for the successful treatment of an anomaly.

Cysts and Tumors of the Jaws

The complexity of anterior open bite is attributed to a combination of skeletal, dental, soft tissue, and habitual factors. Multiple treatment strategies aimed at different etiologies of anterior open bite have been proposed. However, the tendency toward relapse after conventional or surgical orthodontic treatment has been indicated. Therefore, anterior open bite is considered one of the most challenging dentofacial deformities to treat. The aim of this article is to review the etiologies, dentofacial morphology, treatment modalities, retention, and stability of anterior open bite. The etiology of anterior open bite malocclusions is multifactorial and numerous theories have been proposed, including genetic, anatomic and environmental factors. The diagnosis and treatment modalities are variable according to the etiology. Failure of tongue posture adaptation subsequent to orthodontic and/or surgical treatment might be the primary reason for relapse of anterior open bite. Prolonged retention with fixed or removable retainers is advisable and necessary in most cases of open bite treatment. The treatment of anterior open bite remains a tough challenge to the clinician; careful diagnosis and timely intervention with proper treatment modalities and appliance selection will improve the treatment outcomes and long-term stability.