Distalization Of Maxillary First Molars Research Articles

Bilateral distalization of maxillary first molars in a group of adult patients after extraction of maxillary second molars using infra-zygomatic mini-implants: A prospective clinical trial

It is now possible to predictably distalize maxillary first molars in nongrowing patients with the infra-zygomatic gear distalizer and to improve malocclusions without having to extract the premolars and regardless of the patient's compliance. The purpose of this study was to investigate the amount and rate of distal movement of the maxillary first molars using our proposed appliance after extraction of maxillary second molars. Ten nongrowing female patients successfully treated with our proposed appliance were the subjects of this study. The amount, rate, and type of distalization, were analyzed through upper jaw cone beam computed tomography (pre- and post-treatment) and scanned casts taken on a monthly interval. The average amount of distalization of the maxillary first molars was 4.03 mm at the crown level and 2.88 mm at the root level. The rate of distalization had an average of 0.61 mm per month with a maximum of 0.79 mm in the first month because of the regional acceleratory phenomena after extracting the maxillary second molar. The maxillary first molars were distalized in a significant manner and all patients reached a Class I relation within an average duration of 6.4 months. The proposed appliance proved to be a viable noncompliance modality to distalize maxillary first molars correcting maxillary Class II malocclusions characterized by maxillary protrusion or maxillary incisor crowding.

Evaluation of Dentoskeletal and Profile Changes with Distal Jet in Moderate Skeletal Class II Patients

In an orthodontic treatment, upper molar distalization is mandatory to gain space in upper arch. Objective: To evaluate the nature of molar distalization & its effects on soft tissue profile, dentoalveolar structures & skeletal structures. Methods: This was a retrospective study design. 20 subjects were found to be eligible for the distalization with average age of 19.4 yrs. Only Distal jet was used for distalization and one operator was there for all the subjects. Pre and post treatment cephalograms were taken to analyze dentoalveolar & soft tissue changes. Paired sample T test was used. Results: Notable amount of molar distalization and increased lower face height was achieved. Conclusions: This study verified definite distalization of maxillary first molars using distal jet showing a better bodily movement with less tipping movement, with certain unwanted & reactionary effects on incisor position & limited effects on facial soft tissues.

Three-dimensional analysis of maxillary dentition during molar distalization with clear aligners under different movement designs: an in vitro experiment

Objective: To investigate the three-dimensional force in the maxillary dentition under different movement designs for molar distalization with clear aligners Methods: Three groups were designed: simultaneous movement group (simultaneous distalization of maxillary first and second molars), second molar movement group (distalization of maxillary second molars) and first molar movement group (distalization of maxillary first molars). Ten clear aligners were made in each group, and the displacement was designed to be 0.2 mm. A force sensing device was established to measure the three-dimensional force on the upper dentition with the clear aligner. The device contained a model of the maxillary dentition consisting of 14 teeth, each tooth connected to an individual sensor. After the clear aligner was fitted, the data of 14 sensors were collected and analyzed using computer analysis software. The moving teeth were taken as the target teeth, and the rest of the teeth were anchorage. The data of the three-dimensional force in the three groups in each tooth position were measured and compared. Results: The sagittal forces on the first and second molars in the simultaneous movement group were (5.61±0.94) and (5.81±1.08) N, respectively, which were significantly smaller than those of the target teeth in the same position in other groups (P<0.05). The second molars in the first molar movement group received a sagittal reaction force, which was (-6.73±1.99) N. The anterior teeth in the three groups were all subjected to sagittal reaction force, and the force value was in a range of (-3.33 to 0.46) N. In the coronal direction, the second premolars of the simultaneous movement group received the reaction force in the palatal direction, and the force value was (-2.17±1.06) N. The first molars in the second molar movement group were also subjected to palatal reaction force of (-1.99±0.70) N. The second molars and second premolars in the first molar movement group were also subjected to palatal reaction force, which were (-2.85±0.57) and (-1.85±0.74) N, respectively. Compared with the sagittal and coronal forces, the target teeth and anchorage teeth in the three groups were less stressed in the vertical direction. Conclusions: The first and second molars distalized simultaneously, the correction force in the sagittal direction was relatively small. When first molar was moved distally alone, a greater reaction force in the sagittal direction was exerted on the second molar. Buccal displacement of the adjacent anchorage teeth should be designed to counteract the palatal reaction force on the anchorage teeth as the molars moved distally.

Apical root resorption in patients treated with en-masse retraction using skeletal anchorage system versus conventional method

Purpose: To compare external apical root resorption EARR in orthodontic patients treated with en-masse retraction with skeletal anchorage (miniscrews) versus two step procedures. Patients and methods: Forty patients were randomly divided into two equal groups. Group I consisted of 20 patients were treated by using mini-screw anchorage and en-masse retraction, while, group II, 20 patients were treated with two-step retraction and conventional methods of anchorage reinforcement. Lateral cephalometric and digital panoramic radiographs were used to evaluate treatment changes just before (T1) and immediately after (T2) retraction of the maxillary anterior teeth. Results: A significant positive correlation between age and root resorption. Shorter treatment duration was needed in group I with insignificant difference between both groups. Significant root resorption in maxillary central, lateral incisors, canines and first molars was found in both groups just after retraction. A significant root resorption was found for maxillary centrals and first molars in mini-implant group compared to conventional anchorage group. Upper first molars were intruded (-1.8 mm, P=0.041) in mini-implant group with no significant distalization (P=0.016) compared to conventional anchorage group. Upper incisors were significantly retracted (-7.8mm, P=0.001) and intruded (-2.3mm, P=0.017) in comparison to other group. Conclusion: Skeletal anchorage system tends to permit more root resorption than conventional anchorage procedure. A significant retraction and intrusion of maxillary incisors, and a significant intrusion and lack of distalization of maxillary first molars by using skeletal anchorage system during en-masse retraction was found when compared with conventional anchorage procedure.

Insertion torque values and success rates for paramedian insertion of orthodontic mini-implants : Aretrospective study.

Orthodontic mini-implants (OMIs) are areliable method to provide temporary orthodontic anchorage. We hypothesized that there is an optimal insertion torque (<10 Ncm) that can be used to ensure the success of self-drilling OMIs in the paramedian region. Included were 40 (26 females, 14 males) consecutive patients requiring palatal skeletal anchorage. Mean age was 17.3years (range 11.0-44.6 years) for female patients and 15.7 years (range 10.6-36.9 years) for male patients. A total of 22 patients received aBeneslider according to Wilmes for the distalization of maxillary first molars, 10patients received aMesialslider for the mesialization of maxillary first molars, and 8patients received abone-borne rapid palatal expansion (RPE) appliance. Torque values of 10-15 Ncm were recorded in 46.3% of the OMIs and 15-20 Ncm in 35% of OMIs. OMIs that endured the orthodontic force applied for ≥6months were considered assuccess. The overall success rate was 98.8%. No significant differences were found between insertion torque values with respect to the right and left sides, Jarabak's ratio, facial axis, and Frankfort to mandibular plane angle. There were no significant differences in the OMIs insertion torques with regard to the different appliances. No association was found between insertion torque and vertical skeletal morphology. With an overall success rate of 98.8%, the study hypothesis that greater insertion torque (>10 Ncm) will decrease the success rate and increase palatal OMI failure was rejected.

Early interception of mandibular shifting: A longitudinal approach from deciduous through mixed and permanent dentitions

AbstractA Class II malocclusion with a unilateral posterior crossbite in the late deciduous dentition is a challenging type of malocclusion to intercept. The objective is to analyze the long-term changes in a patient with a skeletal Class II division 1 malocclusion. A 5-year-old female child who was referred from a pediatric dentist came for consultation. Correction of posterior crossbite involves expansion of the maxillary arch with the aim of removal of occlusal interferences and elimination of the functional shift of the mandible. The treatment comprised three stages: (1) Expansion of the maxillary arch was performed with a modified Haas palatal expander and the clinical procedures thus resulted in improved facial symmetry and satisfactory functional occlusion in the mixed dentition (8 years 10 months). (2) Distalization of maxillary first molars was done with a Kloehn type headgear and a lip bumper was placed in the mandible to maintain the arch perimeter (12 years). (3) A 0.022 inch × 0.028 inch standard edgewise fixed appliance was used for comprehensive orthodontic treatment and the objectives were accomplished (14 years 5 months). The results showed great improvements in function and esthetics, and posttreatment stability was good after 7 years and 5 months.

Evaluation of treatment changes associated with maxillary molar distalization with the distal jet appliance

Objectives: Maxillary molar distalization is one of the non-extraction treatment options to gain space in the maxillary arch for the resolution of class II malocclusions. This retrospective clinical study was aimed at evaluating the nature of maxillary first molar movement after distalization with the distal jet and its effects on incisor position and facial soft-tissues. Materials and Methods: The study sample consisted of 22 subjects (10 boys, 12 girls) having an average age of 13.04 years at the time of obtaining pre-treatment diagnostic records. The distal jet was the only appliance used during the distalization phase of treatment. All patients were treated by a single clinician with strict adherence to a standardized treatment protocol. The average duration of molar distalization was 6.09 months. Pre-treatment and postdistalization lateral cephalograms were obtained to analyze dentoalveolar and soft-tissue changes. Results: This study revealed that the maxillary first molars were distalized by an average of 4.29 mm into a class I molar relationship. In the process, the molars exhibited distal molar tipping (6.66°) and extrusion (1.45 mm). The maxillary incisors were displaced and tipped labially by 1.89 mm and 2.84° respectively, leading to an increase in overjet by 0.86 mm and decrease in overbite by 0.98 mm. The soft-tissue changes involved upper and lower lip protrusion by 0.84 mm and 1.45 mm respectively, with an increase in lower facial height by 1.36 mm. Conclusion: This study confirmed the reliable and effective distalization of maxillary first molars with the distal jet, with certain undesirable and reciprocal effects on incisor position and minimal impact on the facial soft-tissues.

Periodontally Accelerated Molar Distalization With Miniscrew Assisted Memory Screw: A Pilot Study

ABSTRACT Objective: To examine the treatment effects of a miniscrew assisted memory screw system supported by piezoincision for the noncompliance molar distalization of maxillary first molars in patients with Class II malocclusion. Materials and Method: Nine subjects with skeletal Class I dental Class II malocclusion were treated. An anchorage unit was prepared using two miniscrew that were placed just behind a line connecting the first premolars at the mesial contact point. The memory expansion screw (500 g), and two miniscrews placed parallel to the occlusal plane provided stable, 4-point support for the appliance. Piezoincision was performed immediately after the appliance as cemented. Four midlevel incisions were made under local anesthesia between the roots of the teeth on the buccal side of the maxillary alveolar bone from the mesial first premolar to the second molar. A 3-mm piezoelectrical corticotomy was then performed by inserting the tip of Piezotome into each of these openings. Screw activatio...

Editor's Comment and Q&A: Noncompliance maxillary molar distalization with the First Class Appliance: A randomized controlled trial

Introduction The aim of this study was to evaluate the treatment effects of the First Class Appliance (FCA) (Leone, Firenze, Italy) used for the distalization of maxillary first molars in patients with Class II malocclusion and mixed dentition. Methods According to the results of the power analysis for sample size calculation, 32 consecutive patients with bilateral Class II molar relationships were initially included in the study. After application of the inclusion and exclusion criteria 26 patients remained for the final evaluation. They were randomized into 2 groups: treatment group (n = 15) and untreated control group (n = 11). Lateral cephalograms and dental casts were obtained before and immediately after distalization for the treatment group, and initially and approximately 22 weeks later for the control group. Statistical evaluation of the variables included the mixed 2-way analysis of variance at P <0.05. The method error was also estimated. Results The mean treatment period to achieve a full Class I molar relationship was 17.2 weeks. Analysis of the data showed significant distalization of the maxillary first molars produced by the FCA (mean: 4.00 mm) when compared with the untreated group (mean: 0.95 mm). The rate of molar movement was 1.00 mm per month, which, however, was associated with distal tipping of the first molars (8.56°) and anchorage loss of the anterior dental unit in terms of overjet increase (0.68 mm), and mesial movement (1.86 mm) and inclination (1.85°) of the first premolars or first deciduous molars. The maxillary first molars also moved buccally (1.37 mm), but no significant distal rotation occurred. Conclusions The FCA is an efficient noncompliance appliance to distalize molars in the mixed dentition without distal rotations. However, these movements are associated with distal molar tipping and anchorage loss of the anterior teeth. The aim of this study was to evaluate the treatment effects of the First Class Appliance (FCA) (Leone, Firenze, Italy) used for the distalization of maxillary first molars in patients with Class II malocclusion and mixed dentition. According to the results of the power analysis for sample size calculation, 32 consecutive patients with bilateral Class II molar relationships were initially included in the study. After application of the inclusion and exclusion criteria 26 patients remained for the final evaluation. They were randomized into 2 groups: treatment group (n = 15) and untreated control group (n = 11). Lateral cephalograms and dental casts were obtained before and immediately after distalization for the treatment group, and initially and approximately 22 weeks later for the control group. Statistical evaluation of the variables included the mixed 2-way analysis of variance at P <0.05. The method error was also estimated. The mean treatment period to achieve a full Class I molar relationship was 17.2 weeks. Analysis of the data showed significant distalization of the maxillary first molars produced by the FCA (mean: 4.00 mm) when compared with the untreated group (mean: 0.95 mm). The rate of molar movement was 1.00 mm per month, which, however, was associated with distal tipping of the first molars (8.56°) and anchorage loss of the anterior dental unit in terms of overjet increase (0.68 mm), and mesial movement (1.86 mm) and inclination (1.85°) of the first premolars or first deciduous molars. The maxillary first molars also moved buccally (1.37 mm), but no significant distal rotation occurred. The FCA is an efficient noncompliance appliance to distalize molars in the mixed dentition without distal rotations. However, these movements are associated with distal molar tipping and anchorage loss of the anterior teeth.

Noncompliance maxillary molar distalization with the First Class Appliance: A randomized controlled trial

The aim of this study was to evaluate the treatment effects of the First Class Appliance (FCA) (Leone, Firenze, Italy) used for the distalization of maxillary first molars in patients with Class II malocclusion and mixed dentition. According to the results of the power analysis for sample size calculation, 32 consecutive patients with bilateral Class II molar relationships were initially included in the study. After application of the inclusion and exclusion criteria, 26 patients remained for the final evaluation. They were randomized into 2 groups: treatment group (n = 15) and untreated control group (n = 11). Lateral cephalograms and dental casts were obtained before and immediately after distalization for the treatment group, and initially and approximately 22 weeks later for the control group. Statistical evaluation of the variables included the mixed 2-way analysis of variance at P <0.05. The method error was also estimated. The mean treatment period to achieve a full Class I molar relationship was 17.2 weeks. Analysis of the data showed significant distalization of the maxillary first molars produced by the FCA (mean: 4.00 mm) when compared with the untreated group (mean: 0.95 mm). The rate of molar movement was 1.00 mm per month, which, however, was associated with distal tipping of the first molars (8.56 degrees ) and anchorage loss of the anterior dental unit in terms of overjet increase (0.68 mm), and mesial movement (1.86 mm) and inclination (1.85 degrees ) of the first premolars or first deciduous molars. The maxillary first molars also moved buccally (1.37 mm), but no significant distal rotation occurred. The FCA is an efficient noncompliance appliance to distalize molars in the mixed dentition without distal rotations. However, these movements are associated with distal molar tipping and anchorage loss of the anterior teeth.