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.     

Cephalometric comparison of adult anterior open bite treatment using clear aligners and fixed appliances

Objectives:To compare fixed appliances and clear aligner therapy in correcting anterior open bite and in controlling the vertical dimension in adult patients with hyperdivergent skeletal patterns.Materials and Methods:In this retrospective study, two treatment groups of adult (≥18 years old) hyperdivergent patients (mandibular plane angles of ≥38°) with anterior open bites were included: 17 fixed appliance patients and 36 clear aligner patients. Thirteen cephalometric measurements representing the vertical dimension were reported for each group. A two-sample t-test was used to assess differences in changes in mandibular plane angle and overbite between the two treatment groups.Results:There were no statistical differences found in the magnitude of overbite correction and the changes in any of the cephalometric measurements for vertical control. The clear aligner group showed a slightly greater amount of lower incisor extrusion (P = .009). The main mechanism of open bite correction was similar between the two treatment groups and was accomplished through retroclination of the upper and lower incisors while maintaining the vertical position of the upper and lower molars.Conclusions:Cephalometric comparison of anterior open bite correction and changes in the mandibular plane angle associated with use of clear aligners and fixed appliances did not demonstrate statistically significant differences in adult hyperdivergent patients.     

Extreme skeletal open bite correction with vertical elastics

Severe skeletal open bites may be ideally treated with a combined surgical–orthodontic approach. Alternatively, compensations may be planned to camouflage the malocclusion with orthodontics alone. This case report describes the treatment of an 18-year-old man who presented with a severe open bite involving the anterior and posterior teeth up to the first molars, increased vertical dimension, bilateral Class III molar relationship, bilateral posterior crossbite, dental midline deviation, and absence of the maxillary right canine and the mandibular left first premolar. A treatment plan including the extraction of the mandibular right first premolar and based on uprighting and vertical control of the posterior teeth, combined with extrusion of the anterior teeth using multiloop edgewise archwire mechanics and elastics was chosen. After 6 months of alignment and 2 months of multiloop edgewise archwire mechanics, the open bite was significantly reduced. After 24 months of treatment, anterior teeth extrusion, posterior teeth intrusion, and counterclockwise mandibular rotation were accomplished. Satisfactory improvement of the overbite, overjet, sagittal malocclusion, and facial appearance were achieved. The mechanics used in this clinical case demonstrated good and stable results for open-bite correction at the 2-year posttreatment follow-up.     

Long-term stability of anterior open bite closure corrected by surgical-orthodontic treatment

In adults, superior repositioning of posterior maxilla with or without mandibular surgery has become the treatment method of choice to close anterior open bite. Study aim was to examine the long-term stability of anterior open bite closure by superior repositioning of maxilla or by combining maxillary impaction with mandibular surgery. The sample comprised 24 patients who underwent anterior open bite closure by superior repositioning of maxilla (maxillary group, n = 12, mean age 29.3 years) or by maxillary impaction and mandibular osteotomy (bimaxillary group, n = 12, mean age 30.8 years). Lateral cephalograms were studied prior to surgery (T1), the first post-operative day (T2) and in the long term (T3, maxillary group mean 3.5 years; bimaxillary group mean 2.0 years). Paired and two-sample t-tests were used to assess differences within and between the groups. The vertical incisal bite relations were -2.6 and -2.2 mm at T1; 1.23 and 0.98 mm at T2; and 1.85 and 0.73 mm at T3 in the maxillary and bimaxillary groups. At T3, all subjects had positive overbite in the maxillary group, but open bite recurred in three subjects with bimaxillary surgery. For both groups, the maxilla relapsed vertically. Significant changes in sagittal and vertical positions of the mandible occurred in both groups. In the bimaxillary group, the changes were larger and statistically significant. In general, the maxilla seems to relapse moderately vertically and the mandible both vertically and sagittally, particularly when both jaws were operated on. Overbite seems to be more stable when only the maxilla has been operated on.     

Long-term follow-up of orthodontically treated deep bite patients

The aim of this study was to evaluate the long-term stability of corrected deep bite and mandibular anterior crowding in a sample of 62 subjects (30 patients and 32 controls). The patients began treatment at a mean age of 12.2 years (SD 1.56). The treatment consisted of non-extraction and fixed appliances in 23 subjects and functional appliances in seven. The treatment group was compared with the control group with normal molar occlusion, normal overjet and overbite, no crowding, and without an orthodontic treatment need. The registrations were made on four occasions: before treatment (T1), after treatment (T2), and at two long-term follow-ups (T3 and T4). Four registrations were also made in the control group. All measurements were undertaken on plaster models and lateral cephalograms. Treatment was found to have normalized the overbite and overjet and to have eliminated the space deficiency in the mandibular anterior region. At T4, there was a minor relapse in overbite in the treatment group (mean 0.8 mm). In the control group, the overbite underwent reverse development (bite opening by 0.7 mm) during the same period. The available mandibular incisor space, however, was -0.9 mm in the treatment group and -1.8 mm in the control group. The long-term stability of the treatment results was thus good.     

A comparison of the Ricketts and Tweed-type arch leveling techniques

The purpose of this study was to compare the effectiveness and long-term stability of arch leveling and overbite correction carried out by the Ricketts and modified Tweed techniques. The sample comprised 60 Class II, deep bite, low-angle adolescent nonextraction cases, 30 each from the offices of Robert Ricketts and Fred Schudy, with cephalograms taken before and immediately after treatment and an average of more than 4 years after treatment. Both techniques were successful in overbite correction, producing only minimal increases in mandibular plane angle and anterior facial height. Mandibular incisors in the Ricketts group demonstrated more flaring and anterior bodily movement during treatment, with a greater amount of posttreatment uprighting and overbite relapse than the Schudy group. The Ricketts group demonstrated slightly more than 1 mm of true lower incisor intrusion; this change was relatively stable after treatment. Both techniques produced similar amounts of mandibular molar extrusion during treatment; these changes remained stable after treatment.     

Effects of vertical chincap therapy on the mandibular morphology in open-bite patients.

The aim of this study was to investigate the effects of the vertical chincap on mandibular morphology and also on the dentoalveolar structures in patients with high-angle open-bite malocclusions. We examined 35 children with high-angle skeletal Class I or II open-bite malocclusions. Eighteen subjects were selected as the treatment group, and 17 were the controls. Vertical chincaps, applying 400 g on each side from beneath the anterior part of the mandibular corpus in an upward direction, were used in the treatment group for 16 hours per day over a mean period of 9 months. We studied 70 lateral cephalograms taken before and after the treatment and the control periods. The changes of 7 linear and 8 angular parameters were evaluated statistically in both groups with paired and Student t tests, respectively. Eruption of the mandibular incisors, decrease of the ramal inclination, decrease of the mandibular plane, and increase of the overbite in the treatment group compared with the control group were found to be statistically significant. Intrusion of the first molars, decrease of the gonial angle, and increase of the mandibular corpus inclination in the treatment group were contrary to the results observed in the control group; these comparisons were also found to be statistically significant. It appears that the vertical chincap is effective in treating skeletal open bite and in decreasing the gonial angle and ramus/corpus relationship.     

Dentoskeletal effects produced by removable palatal crib,bonded spurs,and chincup therapy in growing children with anterior open bite

Objective:To evaluate the dentoskeletal effects of different anterior open bite treatment modalities in children.Materials and Methods:This cephalometric study assessed changes resulting from different treatment approaches on 77 growing children with anterior open bite. A control group (n = 30) was used for comparison. Lateral cephalograms were available before treatment and after 12 months. The sample was divided into four groups: removable palatal crib associated with a chincup (G1), bonded spurs associated with a chincup (G2), chincup (G3), and nontreated control (G4). Statistical comparisons among the four groups were performed on T1 and the treatment changes using analysis of variance with Tukey''s post hoc tests.Results:No statistically significant changes in skeletal variables were found among the groups, except for lower anterior face height (LAFH) increase in G1. Overall, effects in all of the treated groups were exclusively dentoalveolar. A larger overbite (OB) increase was observed in G1 and G2 when compared with G3 and G4. The maxillary incisors in G1 showed increased palatal tipping, retrusion, and more vertical dentoalveolar development as well as increased lingual tipping among mandibular incisors. There was less vertical development of maxillary and mandibular molars in G3.Conclusions:A removable palatal crib provided an improvement in OB (97.5%), followed by the bonded spurs (84.5%). Conversely, the chincup-only group did not have positive OB effects.     

拔除第二双尖牙矫正病例(牙合)颌面的垂直向变化

目的　评价安氏 I类错畸形患者,特别是下颌平面角较大的患者拔除第二双尖牙矫正后颌面的垂直向变化,尤其是下颌平面的旋转变化。方法　24 例覆正常或较浅且下颌平面角大于均值的安氏 I类错患者(骨性与牙性均为 I类)拔除第二双尖牙,应用直丝弓技术完成矫治,25 例符合同样标准的患者由不拔牙矫正完成。对所有病例治疗前后的头颅侧位片进行描图和手工测量,比较拔牙组与非拔牙组颌面垂直向的变化。结果　对拔牙和非拔牙两组患者的头影测量结果进行的统计学比较发现,除下磨牙的伸长量拔牙组大于非拔牙组外,两组患者间颌面垂直向的变化并无统计学意义的差别。结论　第二双尖牙的拔除并不一定意味着下颌平面角的减小,对于高角前牙开倾向病例选择拔除第二双尖牙后,在矫正过程中仍需注意对后牙的垂直向控制。     

The mandibular plane angle in activator treatment.

The long-term results of activator treatment were investigated in 15 subjects with a small and 13 subject with a large pretreatment mandibular plane angle. The results of the investigation revealed the following: 1. Activator treatment resulted in a general improvement in the sagittal and vertical incisor relationship in both large and small angle cases. 2. Overjet relapse was more frequent and overbite relapse less frequent in large angle cases than in small angle cases. 3. During the period before treatment follow-up examination the frequency of patients with open bite increased in the large angle group and decreased in the small angle group. 4. The mandibular intercanine arch width was smaller and the frequency of crowding in the mandibular incisor segment was higher in the large angle group than in the small angle group. 5. A large pretreatment mandibular plane angle, per se, was not a primary factor in treatment failure. However, an unfavourable mandibular growth in combination with an atypical tongue function seemed to be the main reason for the relapse found in the large angle subjects.     

Treatment and posttreatment effects of quad-helix/crib therapy of dentoskeletal open bite

OBJECTIVE: To investigate the effects of the quad-helix/crib (Q-H/C) appliance in subjects with thumb-sucking habits and dentoskeletal open bite at 2 years after the end of active treatment. MATERIALS AND METHODS: The records of 21 subjects treated with the Q-H/C appliance were compared with a control group of 21 untreated subjects with similar vertical relationships. Lateral cephalograms were obtained before treatment (T1; mean age 8.4 +/- 1.4 years) and at about 2 years after treatment (T2; mean age 11.7 +/- 1.9 years) and analyzed. Mean treatment duration was 1.5 years +/- 7 months. The T2-T1 changes in the two groups were compared with a nonparametric test for independent samples. RESULTS: The mean increase in overbite during Q-H/C therapy (4.1 mm) represented an overcorrection of the amount of anterior open bite at T2. Both the maxillary and mandibular incisors showed significantly greater extrusion in the Q-H/C group than in the control group. The treated group showed a greater downward rotation (1.8 degrees ) of the palatal plane than did the control group. This change was associated with a clinically significant reduction in the palatal plane/mandibular plane angle (-2.5 degrees ) in the Q-H/C group. The upper lip showed significant retraction relative to the E-plane in the treated group (3.6 mm) compared with the controls. CONCLUSIONS: The Q-H/C appliance was effective in correcting dental open bite in 85% of the growing subjects with thumb-sucking habits and dentoskeletal open bites. Correction of anterior open bite was associated with a clinically significant improvement in maxillomandibular vertical skeletal relationships.     

A cephalometric comparison of black open-bite subjects and black normals

Orthodontic surveys of the adolescent and adult population of the United States have shown that the incidence of anterior open bite is three to four times higher in blacks than in whites. A cephalometric comparison of black subjects with and without an open bite was used to identify skeletal and dental differences between the two groups. Statistically significant differences were found in the vertical skeletal dimensions and incisor proclination. The open-bite group had a significantly longer anterior lower facial height and total facial height. The mandibular plane was rotated down relative to the cranial base and Frankfort plane and gonial angle was increased in the open-bite sample. There were small differences between the open bite and non-open-bite groups in the cranial base angle and the overbite depth indicator of Kim. No significant differences were found in the skeletal anteroposterior dimensions or dental vertical development. The vertical skeletal pattern and the greater degree of dental proclination differentiated black patients with an anterior open bite from those without.     

Nonsurgical treatment of skeletal anterior open bite in adult patients: Posterior build-ups

Objective:To (1) evaluate the efficacy of build-ups in the correction of anterior open bite in adults, (2) evaluate their efficacy in producing molar intrusion, (3) analyze skeletal and dental changes, and (4) assess the long-term stability.Materials and Methods:The sample consisted of 93 lateral cephalograms from 31 patients with skeletal and dental anterior open bite. The patients had received orthodontic treatment consisting of bonded resin blocks on the maxillary molars combined with Tip-Edge Plus bracket appliances. Cephalometric measurements were performed on radiographs taken before treatment (T1), after treatment (T2), and after a retention period (T3), which were analyzed and compared.Results:Significant dental and skeletal changes were observed after treatment. Molar intrusion averaging 1 mm; 1.44 and 1.57 mm extrusion of mandibular and maxillary incisors, respectively; and a mean of 3.98 mm overbite increase were observed. The mandibular plane angle showed a mean closure of 1.19°, and there was a mean decrease in anterior facial height of 0.7 mm. A mild relapse tendency was observed, but long-term stability was acceptable.Conclusions:Build-ups are an effective treatment alternative for anterior open bite in adults. Outcomes remain significantly stable during the retention period.     

Dentoalveolar compensation in Iranian adult skeletal open bite subjects

PurposeThe aim of present study was to compare skeletal and dentoalveolar features of compensated and noncompensated adult open bite subjects with each other and also with those of control group.Materials and methodsA total of 100 lateral cephalograms were included in the study and were divided according to skeletal vertical characteristics into two groups: control group (CG) and open bite group (OBG). The OBG further divided into two subgroups based on amount of overbite: dentally compensated open bite group (COBG) and non compensated open bite group (NCOBG). Twenty skeletal and dentoalveolar variables were evaluated and compared between OBG and CG and also between open bite subgroups by means of Student t-test. Association between different variables and overbite was assessed using Pearson's correlation coefficient.ResultsIncreased molar and incisor height in both jaws were observed in OBG compared to CG. In NCOBG lower anterior facial height and lower posterior dentoalveolar height were significantly higher than COBG.ConclusionDentoalveolar compensatory mechanisms in skeletal open bite patients consist of increased anterior and posterior dentoalveolar heights in upper and lower jaws compared to CG, while decreased mandibular molar height and shorter anterior face height are the most important determinants of adequate compensation in skeletal open bite subjects in our sample.     

A cephalometric study of 32 North American black patients with anterior open bite

The purpose of this research project was to investigate a group of 32 North American black patients with anterior open bite and compare them to the North American black norms established by Altemus and Drummond and to white population norms established by Steiner. In addition, values were established for black patients by use of the overbite depth indicator of Kim. The method involved the tracing of lateral cephalometric radiographs of 32 patients with anterior open bite using the analyses of Tweed, Steiner, and Kim. The resulting angles were added and the means and standard deviations calculated. On the basis of the criteria used for this study, the significant findings were as follows: (1) the maxilla was normally positioned to the cranial base; (2) the upper and lower incisors were procumbent with an acute interincisal relationship; (3) the mandibular position tended to be retrusive to the cranial base; (4) the lower facial height was greater and the mandibular plane angle (GoGn-SN) was smaller than white population standards; and (5) the overbite depth indicator of Kim was smaller for this group than for the white population studied.     

Anterior open bite in the deciduous dentition: longitudinal follow-up and craniofacial growth considerations.

The aim of this longitudinal cephalometric study was to evaluate craniofacial growth changes in subjects with an anterior open bite in the deciduous dentition. From longitudinal records of untreated subjects, an open bite group (n = 14) was selected at the age of 5 years based on the presence of a negative overbite and compared with a control group (n = 14) with a regular overbite at this age. Cephalometric measurements were analyzed at ages 5, 9, and 12 years. Although only 1 subject in the deciduous dentition open bite group had an open bite at 12 years of age, the overbite remained lower during the longitudinal follow-up. Early cephalometric characteristics of the open bite group included a reduced overbite depth indicator and a lower ANB angle. At ages 9 and 12 years, the open bite sample was also characterized by shorter ramus height. An underlying skeletal pattern seems to be present in the deciduous dentition open bite sample that persists during the longitudinal follow-up. The overbite depth indicator might help to identify patients with anterior open bite tendencies.     

Evidence of correction of open bitemalocclusion using active vertical corrector treatment

This study used a cephalometric analysis that isolated tipping and bodily tooth movements of the upper and the lower incisors and measured vertical skeletal changes in the anterior region of the maxilla and mandible to evaluate the outcome of two-phase nonextraction treatment for open bite malocclusion. Twenty-nine subjects treated with an active vertical corrector (AVC) followed by fixed 022 orthodontic appliances were selected by one orthodontist from his private practice. All subjects lacked vertical incisor contact at the start of treatment and had adequate initial, end of phase 1, and deband lateral cephalograms. Each subject in the treated group was matched by age and sex with an untreated subject from the Broadbent Bolton Collection, Cleveland, OH. Data were collected for three time intervals; phase 1 treatment with the AVC (T1 to T2), phase 2 fixed-appliance treatment (T2 to T3), and over the total treatment period (T1 to T3). Analysis of the data showed no statistically significant (P < or = .002) changes between treated subjects and controls for any variables during the phase 1 (T1 to T2) or phase 2 (T2 to T3) treatment intervals. However, overbite was significantly improved compared with controls (P < or = .002) during the T1 to T3 time interval. It was concluded that two-phase treatment with the AVC followed by fixed orthodontic appliance treatment results in a statistically significant increase in incisor overbite. The observed increase in overbite was the result of small but clinically significant changes in relative mandibular vertical growth, bodily incisor movement toward the occlusal plane, and lingual tipping of the lower incisors.     

Orthodontic treatment of overbite with an appliance for raising the anterior vertical dimension. Part 2

If incisor overbite in the matter of orthodontic treatment entails difficulties with the appliances due to excessive overbite of the incisors, involving an anterior bite raiser to enable the unlocking of the occlusion and the bonding of the brackets on the anterior mandibular teeth poses the problem of the vertical behavior of the masticatory apparatus during treatment. A profile teleradiograph was therefore taken at the beginning of treatment and again once the occlusion had been lifted due to the presence of the bite raiser and within a period of three months. The sample was separated in two groups according to the value of FMA; a first group was composed of 44 cases exhibiting an FMA angle inferior to 25 degrees therefore similar to the cases analyzed by Dake and Sinclair in 1989, called "reference group" and a group of cases exhibiting an FMA angle superior to 25 degrees. The aim of this study is indeed to confront, as regards vertical behavior, the therapeutic approach of the authors with the one studied by Dake and Sinclair dealing with cases treated with Ricketts and Tweed technique (Schudy modified). Following Dake and Sinclair's approach, the authors managed to find out in cases with FMA inferior to 25 degrees that the vertical alterations in the study group were not different from those in the reference group. This means that in spite of the presence of an anterior bite raiser the mandibular plane angle had only increased by 1.8 degree, compared to 1.8 degree for the Ricketts group and 1.1 degree for the Tweed/Schudy group. As for the study sample with an FMA angle superior to 25 degrees, the vertical alterations in the study group show an increase of the angle of the mandibular plane equal to 1.2 degree, here again the increase is similar to the one observed in the reference group. It can thus be concluded that the use of an anterior bite raiser in conjunction with the Tip-Edge technique is not only advisable but strongly recommended both to unlock the occlusion but also to enable bracket bonding at the very beginning of treatment.     

Long-term evaluation of rapid maxillary expansion and bite-block therapy in open bite growing subjects: A controlled clinical study

Objective:To evaluate the long-term effects of rapid maxillary expansion (RME) and posterior bite block (BB) in prepubertal subjects with dentoskeletal open bite.Materials and Methods:The treatment group (TG) comprised 16 subjects (14 girls, 2 boys) with dentoskeletal open bite with a mean age of 8.1 ± 1.1 years treated with RME and BB. Three consecutive lateral cephalograms were available before treatment (T1), at the end of the active treatment with the RME and BB (T2), and at a follow-up observation at least 4 years after the completion of treatment (T3). The TG was compared with a control group (CG) of 16 subjects (14 girls, 2 boys) matched for sex, age, and vertical skeletal pattern. An independent sample t-test was used to compare the T1 to T3, T1 to T2, and T2 to T3 cephalometric changes between the TG and the CG.Results:In the long term, the TG showed a significantly greater increase in overbite (+1.8 mm), reduced extrusion of maxillary and mandibular molars (−3.3 mm), and, consequently, a significant decrease in facial divergence (−2.8°) when compared with untreated subjects.Conclusions:The RME and BB protocol led to successful and stable recovery of positive overbite in 100% of the patients considered. Correction of open bite was associated with reduced extrusion of maxillary and mandibular molars with a significant improvement in vertical skeletal relationships when compared with the CG.     

Malocclusion in the primary dentition

In this paper we analyze the type and frequency of malocclusions in a group of 100 health children with complete primary dentition. Bjork's method for epidemiological registration was taken as a basis. Of the examined children, 78% had some malocclusion type. The most frequent was the increased horizontal overbite. In vertical overbite relation we find anterior open bite, increased overbite, anterior open bite, increased overbite.