Correction of Class?II, Division 2 malocclusions using a completely customized lingual appliance and the Herbst device

Aim

The purpose of the present study was to examine the efficiency of correcting a Class?II, Division?2 malocclusion using a completely customized lingual appliance.

Materials and methods

In 18 consecutively completed, Class?II, Division?2 malocclusion patients, the correction of the upper incisor inclination, deep and distal bite were assessed by means of plaster casts, digital lateral cephalograms, and intraoral photographs taken at the time of debond. Furthermore, two independent calibrated examiners determined the weighted Peer Assessment Rating index (PAR Index) of the initial and end models.

Results

All Class?II, Division?2 patients were treated successfully: upper incisor inclination using the palatal plane as a reference improved on average from 95.4° to 111.2°. The deep bite was reduced on average from 3.6?mm to 1.7?mm. Neutral occlusion was achieved in all patients who had undergone correction of an initially pronounced distal occlusion (4.5?mm on average). An 86.2% marked improvement was observed in the weighted PAR index score from an average of 24.7 at the beginning of treatment to 2.9 at the end of treatment, with no patient classified as ??worse or no different.??

Conclusion

Class?II, Division?2 malocclusions can be efficiently and reliably treated by a combination of a completely customized lingual appliance and the Herbst device.     

Dental compensation for moderate Class?III with vertical growth pattern by extraction of the lower second molars

Objectives

Analysis of the effects and side effects of treatment of patients with moderate skeletal Class?III and vertical growth pattern by means of extraction of the second molars in the lower jaw.

Patients and methods

A total of 20 patients with a mean age of 12.9 years were examined retrospectively. Inclusion criteria consisted of a Wits value of 0 to ?5, a posterior growth pattern of the mandible (Hasund analysis), an overjet of ?2 to 1?mm, and an overbite of 0 to ?3?mm. Treatment was performed using a straight-wire appliance. As part of the treatment, the lower second molars were extracted and Class?III elastics attached. Cephalograms and orthopantomograms taken before and after treatment were used for evaluation.

Results

Treatment resulted in a significant change in the mean overjet from 0.5?mm to 2.1?mm and the attainment of a positive mean overbite of ?1.0?mm to 0.9?mm. The occlusal plane rotated anteriorly from 18.8° to 13.7°. The skeletal parameters showed a change in the Wits value from ?3.3?mm to ?1.4?mm and an anterior mandibular rotation (ML-NSL 35.5° vs. 32.0°). The soft tissues revealed an increase in the distance between the lower lip and the ??esthetic line?? to the posterior (?2.0?mm vs. ?3.9?mm).

Conclusion

Dental compensation of moderate skeletal Class?III with a tendency to an anterior open bite with vertical growth pattern by extracting the lower second molars, combined with Class III elastics, resulted in an anterior rotation of the occlusal plane and mandible. Eighteen of 20 patients achieved a physiological overjet and positive overbite. A prerequisite for this therapy is the presence of lower wisdom teeth; a potential side effect is elongation of the upper second molars.     

Combined fixed–functional treatment of skeletal class II malocclusions with the EVAA appliance

Objectives

The aim of this study was to compare the skeletal and dental effects of the EVAA appliance with those of an activator appliance in growing children with skeletal Class II anomalies.

Materials and methods

A total of 34 subjects with Class II anomalies were recruited for this study. They were divided into three groups: the EVAA group (n=13; mean chronological age: 11 years 9 months), activator group (n=13; mean chronological age: 11 years 8 months) and control group (n=8; mean chronological age: 10 years 8 months). Lateral cephalometric radiographs were taken at the beginning and end of functional therapy. Fixed orthodontic treatment was completed in the EVAA group. A statistical software program (SPSS 18) was used for one-way analysis of variance and multiple comparisons with the Duncan test.

Results

We observed a significant decrease in the ANB, convexity, and 1┴NA (°), while a significant increase appeared in upper anterior facial height, posterior facial height, 1┴NB (mm), SN-lower occlusal plane values in the EVAA and activator groups after treatment (p<0.05). No significant difference in study parameters in the control group during the treatment period except for the increase in SNA and 1┴NA (mm) values (p<0.05) were observed. There were no significant differences between EVAA and activator treatment groups in terms of study parameters except for the articular angle, which was significantly higher in the EVAA group after therapy (p<0.05).

Conclusion

The effects of EVAA appliances were similar to those of activator treatment.     

Soft-tissue changes associated with different surgical procedures for treating class III patients

Objective

The aim of this study was to evaluate the effects of different surgical procedures on soft tissue and skeletal changes.

Patients and methods

Pre- and postoperative lateral cephalograms of 191 class III patients aged 16–58 years were retrospectively analyzed and divided into three groups according to the surgical therapy they had undergone. Group I had undergone maxillary advancement (n=51), group II a bimaxillary (n=102) procedure, and group III mandibular setback (n=38). Cephalometric assessments were made at the beginning of orthodontic treatment (T1) and at least 8 weeks after surgical correction of the class III malocclusion (T2). Nasolabial angle and the distance between the lower lip and the esthetic line were evaluated as soft-tissue parameters, while the skeletal parameters included the SNA and SNB angles, Wits value, gonial angle, and relative position of the maxilla to mandible. Mean values and standard deviations were calculated and any significant difference between soft and hard tissue in association with surgery methods was determined applying the Wilcoxon test using SAS statistical software.

Results

Compared to mandible setback, the number of bimaxillary procedures and maxilla advancements has increased significantly in recent years (0.04). SNA values measured at T2 were an average of 84° in group I, 83° in group II, and 82° in group III, thus, revealing a tendency to return to the normal range. SNB values measured at T2 averaged 81° in group I, 80° in group II, and 81° in group III. We observed significant changes in the nasolabial angle according to the surgical approach taken (p=0.018). Changes in the distance between the lower lip and the esthetic line were only slightly significant (p=0.050). No significant differences were noted among the surgical approaches in terms of SNA and SNB angles.

Conclusion

The two groups that underwent advancement of the maxilla (groups I and II) revealed marked improvements in soft-tissue esthetics.     

Accelerated Osteogenic Orthodontics? for retreatment of a patient with diminished root length and absence of the maxillary central incisor

An 18-year-old female patient visited a university orthodontics department with a chief complaint of an unesthetic appearance of her teeth, including a protruded upper central incisor and unsatisfactory results from previous orthodontic treatment. Pretreatment records showed a Class II skeletal and dental relation with proclined upper and lower incisors, replacement of an absent upper left central incisor with the left upper cuspid, presence of the upper left deciduous cuspid, mild crowding, and 4 mm of overbite and overjet. The panoramic radiograph showed shortened roots of multiple teeth. Accelerated Osteogenic Orthodontics™ (AOO™) was recommended as an approach to reduce the treatment time and the risk of further root shortening. Despite being more expensive and requiring a surgical procedure, this treatment option was very attractive to the patient. The overall treatment time was 14 months. Facial balance was improved, and good occlusal relationships were achieved from the functional and esthetic perspectives. In conclusion, surgically facilitated orthodontics (specifically, AOO™) is an efficient and safe therapeutic tool for treating or retreating orthodontic patients with diminished root length.     

Evaluation of relapse after orthodontic therapy combined with orthognathic surgery in the treatment of skeletal class III

Introduction

Multidisciplinary treatment of skeletal malocclusion by orthognathic surgery in addition to orthodontics is a routine strategy believed to offer good functional and esthetic outcomes. Postoperative relapse is, however, a problem. The present study was conducted to analyze the stability of outcomes achieved by surgical treatment of skeletal class III patients in terms of the rate and extent of relapses.

Patients and methods

A total of 30 patients who had undergone orthodontic treatment combined with orthognathic surgery were included. The primary inclusion criterion was a skeletal class III treated by mandibular setback (Obwegeser/Dal Pont) surgery alone or combined with maxillary advancement (Le Fort I) surgery. Analysis was based on one preoperative and two postoperative cephalograms per patient.

Results

We observed relapse (defined, in accordance with Proffit, as changes >2 mm or 2°) at a rate of 24% after bimaxillary procedures, compared to a lower rate of 21% after mandibular setback procedures only. The relapse rate was 21% among patients who had undergone upper-jaw surgery versus 27% among those who had undergone lower-jaw surgery, which was statistically significant.

Conclusion

The majority of patients exhibited stable treatment outcomes. Maxillary advancement procedures were found to be less susceptible to relapse—resulting in more stable outcomes—and mandibular setback distances correlated positively with the degree of the relapse. No statistically significant differences were observed between the procedures conducted in both jaws versus in the lower jaw only, or in the extent of upper-jaw repositioning.     

Fabrication of an unconventional bolus-type stent for a combined intraoral/extraoral defect treated with proton radiation therapy

Customized intraoral devices help the radiation oncologist minimize the adverse effects of radiation and maximize the tumor control rate by keeping the anatomic structures in a consistent position during each fraction of radiation treatment. This article illustrates the fabrication of a bolus-type positioning device for a combined intraoral/extraoral defect treated with proton radiation therapy.     

Surgery-first approach for correction of class III dentofacial deformity with Le Fort I osteotomy; is it advantageous?

The surgery-first approach (SFA) to orthognathic treatment aims to reduce its duration without compromising the outcome. However, the objective assessment of the achieved occlusion has been limited. This study was designed to assess the treatment duration, outpatient appointment number, and quality of occlusal outcomes for two groups of patients; one treated with the SFA and the other with an orthodontics-first approach (OFA). We carried our a retrospective cohort study of case records for twenty consecutive SFA, and 23 consecutive OFA, cases with class III malocclusions, treated with Le Fort I maxillary osteotomy only. Pre-and post-treatment study models were assessed using the Peer Assessment Rating (PAR). Significant differences (p<0.001) were found between the median active treatment durations (10.2 months for the SFA and 32.5 months for the OFA) and appointment numbers (14 for SFA and 24 for OFA). Median absolute PAR reductions were 40 for the SFA and 39 for the OFA. There was no significant difference between the groups regarding quality of occlusal correction. Treatment durations for the SFA group were significantly shorter than for the OFA group, with fewer outpatient appointments. The quality of occlusal outcome for both SFA and OFA groups were satisfactory and comparable.     

Development of a novel anatomical thin titanium mesh plate with reduction guidance and fixation function for Asian zygomatic-orbitomaxillary complex fracture

For this study we developed an anatomical thin titanium mesh (ATTM) plate for Asian zygomaticomaxillary complex (ZMC) fracture repair with reduction guidance and fixation function. The ATTM plate profile was designed as an L-shape to fix at the anterior maxilla and lateral buttress of the ZMC. Computer-aided stamping analysis was performed on four screw-hole patterns in the ATTM plate — a control without screw-holes, square screw-holes, double screw-holes, and large-diameter, double screw-holes — using upper/lower dies of averaged ZMC reconstruction models. A regular ATTM plate of 0.6 mm thickness was manufactured and pre-bent using a patient-matched stamping process to verify its feasibility on three ZMC fracture models with one, two, and three fracture segments. The stamping analysis found that the double screw-holes design resulted in the most favorable performance among all the designs because of maximum von Mises stress (408 MPa) under the ultimate tensile strength. Positioning practice showed that the stamped, pre-bent ATTM plate can be used as a reduction guide to provide precise ZMC segment fixation in a completely passive fashion while limiting redundant rotation/micromovement between the separate bones in all directions.This study concluded that the ATTM plate with double screw-hole pattern design, using a patient-matched, pre-bent technique, can fit the ATTM plate/ZMC interface well, decrease mobility of unstable fracture segments, and provide good original facial contour recovery, while improving reduction efficiency.     

Accuracy of a chairside fused deposition modeling 3D-printed single-tooth surgical template for implant placement: An in vitro comparison with a light cured template

PurposeTo compare the accuracy of a chairside fused deposition modeling (FDM) 3D-printed surgical template with that of a light-cured template for implant placement.Materials and methodsTwenty standard mandibular resin models with missing teeth 36 and 46 were selected. Surgical templates were fabricated using a chairside FDM 3D-printer (test group) or a light-curing 3D printer (control group) (n = 20/group). Forty implants were placed by a clinician blinded to group allocation. The angular, 3D, mesiodistal, buccolingual, and apicocoronal deviations at the implant base and tip between preoperative design and postoperative implant position were recorded.ResultsThe mean angular (test vs control groups: 3.22° ± 1.55° vs 2.74° ± 1.24°, p = 0.343) and 3D deviations at the implant base (test vs control groups: 0.41 ± 0.13 mm vs 0.35 ± 0.11 mm, p = 0.127) and tip (test vs control groups: 0.91 ± 0.34 mm vs 0.75 ± 0.28 mm, p = 0.150) were similar. The mesiodistal, buccolingual, and apicocoronal deviations at the implant base and tip also did not differ significantly between groups (p > 0.05).ConclusionsFor single tooth gap indications, implant placement with an FDM 3D-printed surgical template was as accurate as that with a light-cured template, and more efficient.     

Needle breakage during local anesthesia in the oral cavity—a retrospective of the last 50 years with guidelines for treatment and prevention

Needle breakage in the oral cavity after local anesthesia is a common complication with possible serious complications of injuring vital structures. There are different possible reasons for needle breakage, with a main focus on preventable mistakes in treatment. In this study, an analysis of literature of the last 50 years as well as own cases has been performed to renew knowledge and prevention and therapy strategies for this serious complication. A systematic, multilingual review of medical literature from 1900 until today was conducted and information was evaluated systematically. In the majority of cases needle fracture happened during inferior alveolar nerve block. It is mainly a problem due to inadequate technique or the use of too thin needles for the performance of inferior alveolar nerve block. Different arguments about possible therapy strategies and methods exist. Basically, if a hypodermic needle fractures, it should be removed surgically under general anesthesia. To localize the fragment, use of either multi-plane X-rays or fluoroscopy with at least two reference needles in place or, if possible, of three-dimensional CT scans is recommended. This article shows, that despite progression in material, needle fracture is still an existing, preventable problem, if some basic rules are followed.