Split orthodontic airway plate: An innovation to the utilization method of conventional orthodontic airway plate for neonates with Robin sequence / 대한치과교정학회지

Since the emergence of neonatal infant orthodontics for treatments of cleft lip and palate with or without Robin sequence (RS) in Europe in the 1950s, advancements in design and scope of its application have been remarkable. As the first institution to adopt orthodontic airway plate (OAP) treatment in the United States in 2019, we saw a need for innovation of the original design to streamline the most labor-intensive and time-consuming aspects of OAP utilization. A solution is introduced using a systematic split expansion mechanism to re-size the OAP periodically to accommodate the neonate’s maxillary growth. To date, seven RS patients have received this modified treatment protocol at our institution. Each patient completed full treatment using only one OAP. This innovative utilization method is aptly named the split orthodontic airway plate (S-OAP). Details of the S-OAP and its modifications from conventional OAP are reported.

Evaluation of strategic uprighting of the mandibular molars using an orthodontic miniplate and a nickel-titanium reverse curve arch wire: Preliminary cephalometric study / 대한치과교정학회지

Objective@#To evaluate the overall treatment effects in terms of the amount of uprighting with changes in the sagittal and vertical positions of mandibular molars after applying an orthodontic miniplate with a nickel-titanium (NiTi) reverse curve arch wire (biocreative reverse curve [BRC] system). @*Methods@#A total of 30 female patients (mean age, 25.99 ± 8.96 years) were treated with the BRC system (mean BRC time, 10.3 ± 4.07 months). An I-shaped C-tube miniplate (Jin Biomed) was placed at the labial aspect for the alveolar bone of the mandibular incisors. A 0.017 × 0.025-inch NiTi reverse curve arch wire was engaged at the C-tube mini-plate anteriorly and the first and second premolars and molars posteriorly in the mandibular arch. Pre- and post-BRC lateral cephalograms were analyzed. A paired t-test was used to analyze the treatment effects of BRC. @*Results@#The mandibular second molars were intrusively uprighted successfully by the BRC system. Distal uprighting with a controlled vertical dimension was noted on the first molars when they remained engaged in the BRC and the distal ends of the arch wire were laid on the second molars. The mandibular first and second premolars showed a slight extrusion. The changes in the mandibular incisors were unremarkable, while the mandibular molar angulation improved significantly. The lower occlusal plane rotated counterclockwise (MP-LOP:1.13° ± 2.60°). @*Conclusions@#The BRC system can provide very effective molar uprighting without compromising the position of the mandibular anterior teeth.

Treatment of a Horizontally Impacted and Dilacerated Maxillary Central Incisor and an Impacted Canine

During orthodontic treatment of impacted teeth, use of appropriate anchorage against the traction force is important. Tooth anchorage with multi-bracket appliances is commonly used but sometimes it causes unwanted movements of adjacent teeth. Skeletal anchorage devices are therefore considered to minimize such side effects. Still their survival rate and positioning are highly limited according to the bone density and the interradicular space. This case report presents a case of two impacted teeth, one of which is dilacerated and horizontally angulated. Using the microplate with short screws and a bendable neck, negative effects on adjacent teeth were minimized and impacted teeth were repositioned with good stability.

Evaluation of strategic uprighting of the mandibular molars using an orthodontic miniplate and a nickel-titanium reverse curve arch wire: Preliminary cephalometric study / 대한치과교정학회지

Objective@#To evaluate the overall treatment effects in terms of the amount of uprighting with changes in the sagittal and vertical positions of mandibular molars after applying an orthodontic miniplate with a nickel-titanium (NiTi) reverse curve arch wire (biocreative reverse curve [BRC] system). @*Methods@#A total of 30 female patients (mean age, 25.99 ± 8.96 years) were treated with the BRC system (mean BRC time, 10.3 ± 4.07 months). An I-shaped C-tube miniplate (Jin Biomed) was placed at the labial aspect for the alveolar bone of the mandibular incisors. A 0.017 × 0.025-inch NiTi reverse curve arch wire was engaged at the C-tube mini-plate anteriorly and the first and second premolars and molars posteriorly in the mandibular arch. Pre- and post-BRC lateral cephalograms were analyzed. A paired t-test was used to analyze the treatment effects of BRC. @*Results@#The mandibular second molars were intrusively uprighted successfully by the BRC system. Distal uprighting with a controlled vertical dimension was noted on the first molars when they remained engaged in the BRC and the distal ends of the arch wire were laid on the second molars. The mandibular first and second premolars showed a slight extrusion. The changes in the mandibular incisors were unremarkable, while the mandibular molar angulation improved significantly. The lower occlusal plane rotated counterclockwise (MP-LOP:1.13° ± 2.60°). @*Conclusions@#The BRC system can provide very effective molar uprighting without compromising the position of the mandibular anterior teeth.

New approach of maxillary protraction using modified C-palatal plates in Class III patients / 대한치과교정학회지

Maxillary protraction is the conventional treatment for growing Class III patients with maxillary deficiency, but it has undesirable dental effects. The purpose of this report is to introduce an alternative modality of maxillary protraction in patients with dentoskeletal Class III malocclusion using a modified C-palatal plate connected with elastics to a face mask. This method improved skeletal measurements, corrected overjet, and slightly improved the profile. The patients may require definitive treatment in adolescence or adulthood. The modified C-palatal plate enables nonsurgical maxillary advancement with maximal skeletal effects and minimal dental side effects.

Simultaneous Glossectomy with Orthognathic Surgery for Mandibular Prognathism / 대한악안면성형재건외과학회지

Macroglossia can create dental and skeletal instability after orthodontic treatment or orthognathic surgery for mandibular prognathism. In relevant literature, partial glossectomy is suggested for a good post-treatment prognosis. Most of the published partial glossectomy cases are two-staged surgery, because of concern about postoperative airway obstruction. As orthognathic surgical techniques and fixation method develop, however, concerns about postoperative airway obstruction have lessened. In this case, mandibular setback surgery and partial glossectomy were performed simultaneously, leading to stable recovery without any postoperative respiratory problems. After surgical technique to preserve the tongue tip, we achieved good outcomes without postoperative side effects of lingual hypoesthesia, pronunciation disorder and dyskinesia. We report this case with a literature review.

Treatment and retention of relapsed anterior open-bite with low tongue posture and tongue-tie: A 10-year follow-up / 대한치과교정학회지

The purpose of the current report is to present 6-year long-term stability and 10-year follow-up data for an adult patient who was treated with a tongue elevator for relapsed anterior open-bite. The 19-year-old male patient presented with the chief complaint of difficulty in chewing his food. Collectively, clinical and radiographic examinations revealed an anterior open-bite, low tongue posture, and tongue-tie. The patient opted for orthodontic treatment alone, without any surgical procedure. A lingual frenectomy was recommended to avoid the risk of relapse, but the patient declined because he was not experiencing tongue discomfort. Initial treatment of the anterior open-bite with molar intrusion and tongue exercises was successful, but relapse occurred during the retention period. A tongue elevator was used for retreatment, because the approach was minimally invasive and suited the patient's requirements regarding discomfort, cost, and time. The appliance changed the tongue posture and generated an altered tongue force, which ultimately resulted in intrusive dentoalveolar effects, and a subsequent counterclockwise rotation of the mandible. The results showed long-term stability and were maintained for six years through continual use of the tongue elevator. The results of this case indicated that a tongue elevator could be used not only as an alternative treatment for open-bite, but also as an active retainer.

En-masse retraction with a preformed nickel-titanium and stainless steel archwire assembly and temporary skeletal anchorage devices without posterior bonding / 대한치과교정학회지

OBJECTIVE: To evaluate the therapeutic effects of a preformed assembly of nickel-titanium (NiTi) and stainless steel (SS) archwires (preformed C-wire) combined with temporary skeletal anchorage devices (TSADs) as the sole source of anchorage and to compare these effects with those of a SS version of C-wire (conventional C-wire) for en-masse retraction. METHODS: Thirty-one adult female patients with skeletal Class I or II dentoalveolar protrusion, mild-to-moderate anterior crowding (3.0-6.0 mm), and stable Class I posterior occlusion were divided into conventional (n = 15) and preformed (n = 16) C-wire groups. All subjects underwent first premolar extractions and en-masse retraction with pre-adjusted edgewise anterior brackets, the assigned C-wire, and maxillary C-tubes or C-implants; bonded mesh-tube appliances were used in the mandibular dentition. Differences in pretreatment and post-retraction measurements of skeletal, dental, and soft-tissue cephalometric variables were statistically analyzed. RESULTS: Both groups showed full retraction of the maxillary anterior teeth by controlled tipping and space closure without altered posterior occlusion. However, the preformed C-wire group had a shorter retraction period (by 3.2 months). Furthermore, the maxillary molars in this group showed no significant mesialization, mesial tipping, or extrusion; some mesialization and mesial tipping occurred in the conventional C-wire group. CONCLUSIONS: Preformed C-wires combined with maxillary TSADs enable simultaneous leveling and space closure from the beginning of the treatment without maxillary posterior bonding. This allows for faster treatment of dentoalveolar protrusion without unwanted side effects, when compared with conventional C-wire, evidencing its clinical expediency.

Torque control during lingual anterior retraction without posterior appliances / 대한치과교정학회지

OBJECTIVE: To evaluate the factors that affect torque control during anterior retraction when utilizing the C-retractor with a palatal miniplate as an exclusive source of anchorage without posterior appliances. METHODS: The C-retractor was modeled using a 3-dimensional beam element (0.9-mm-diameter stainless-steel wire) attached to mesh bonding pads. Various vertical heights and 2 attachment positions for the lingual anterior retraction hooks (LARHs) were evaluated. A force of 200 g was applied from each side hook of the miniplate to the splinted segment of 6 or 8 anterior teeth. RESULTS: During anterior retraction, an increase in the LARH vertical height increased the amount of lingual root torque and intrusion of the incisors. In particular, with increasing vertical height, the tooth displacement pattern changed from controlled tipping to bodily displacement and then to lingual root displacement. The effects were enhanced when the LARH was located between the central and lateral incisors, as compared to when the LARH was located between the lateral incisors and canines. CONCLUSIONS: Three-dimensional lingual anterior retraction of the 6 or 8 anterior teeth can be accomplished using the palatal miniplate as the only anchorage source. Using LARHs at different heights or positions affects the quality of torque and intrusion.

Correction of dental Class III with posterior open bite by simple biomechanics using an anterior C-tube miniplate / 대한치과교정학회지

In the correction of dental Class III molar relationship in skeletal Class II patients, uprighting of the mandibular posterior segments without opening the mandible is an important treatment objective. In the case reported herein, a C-tube miniplate fixed to the lower labial symphysis and connected with a nickel-titanium reverse-curved archwire provided effective uprighting of the lower molars, without the need of orthodontic appliances on the mandibular anteriors. Using this approach, an appropriate magnitude of force is exerted on the molars while avoiding any negative effect on the mandibular anteriors.

The effects of different pilot-drilling methods on the mechanical stability of a mini-implant system at placement and removal: a preliminary study / 대한치과교정학회지

OBJECTIVE: To investigate the effects of different pilot-drilling methods on the biomechanical stability of self-tapping mini-implant systems at the time of placement in and removal from artificial bone blocks. METHODS: Two types of artificial bone blocks (2-mm and 4-mm, 102-pounds per cubic foot [102-PCF] polyurethane foam layered over 100-mm, 40-PCF polyurethane foam) were custom-fabricated. Eight mini-implants were placed using the conventional motor-driven pilot-drilling method and another 8 mini-implants were placed using a novel manual pilot-drilling method (using a manual drill) within each of the 2-mm and 4-mm layered blocks. The maximum torque values at insertion and removal of the mini-implants were measured, and the total energy was calculated. The data were statistically analyzed using linear regression analysis. RESULTS: The maximum insertion torque was similar regardless of block thickness or pilot-drilling method. Regardless of the pilot-drilling method, the maximum removal torque for the 4-mm block was statistically higher than that for the 2-mm block. For a given block, the total energy at both insertion and removal of the mini-implant for the manual pilot-drilling method were statistically higher than those for the motor-driven pilot-drilling method. Further, the total energies at removal for the 2-mm block was higher than that for the 4-mm block, but the energies at insertion were not influenced by the type of bone blocks. CONCLUSIONS: During the insertion and removal of mini-implants in artificial bone blocks, the effect of the manual pilot-drilling method on energy usage was similar to that of the conventional, motor-driven pilot-drilling method.

Histologic assessment of the biological effects after speedy surgical orthodontics in a beagle animal model: a preliminary study / 대한치과교정학회지

OBJECTIVE: Speedy surgical orthodontics (SSO), an innovative orthodontic treatment, involves the application of orthopedic forces against temporary skeletal anchorage devices following perisegmental corticotomy to induce movement of specific dental segments. Herein, we report the biological effects of SSO on the teeth and periodontal structures. METHODS: Five beagle dogs were divided into 2 groups and their 6 maxillary incisors were retracted en masse by applying 500 g orthopedic force against a single palatal mini-plate. Retraction was performed without and with perisegmental corticotomy in groups I and II, respectively. All animals were killed on the 70th day, and their periodontal structures were processed for histologic analyses and scanning electronic microscopy (SEM). The linear distance between the third maxillary incisor and canine was used as a benchmark to quantify the retraction amount. RESULTS: Retraction was markedly faster and retraction amount greater in group II than in Group I. Surprisingly, Group II did not show any root resorption despite extensive retraction, while Group I showed prominent root surface irregularities. Similarly, SEM showed multiple resorption lacunae in Group I, but not in Group II. CONCLUSIONS: SSO is an effective and favorable orthodontic approach for major en masse retraction of the maxillary anterior teeth.

Three-dimensional finite element analysis for determining the stress distribution after loading the bone surface with two-component mini-implants of varying length / 대한치과교정학회지

OBJECTIVE: To evaluate the extent and aspect of stress to the cortical bone after application of a lateral force to a two-component orthodontic mini-implant (OMI, mini-implant) by using three-dimensional finite element analysis (FEA). METHODS: The 3D-finite element models consisted of the maxilla, maxillary first molars, second premolars, and OMIs. The screw part of the OMI had a diameter of 1.8 mm and length of 8.5 mm and was placed between the roots of the upper second premolar and the first molar. The cortical bone thickness was set to 1 mm. The head part of the OMI was available in 3 sizes: 1 mm, 2 mm, and 3 mm. After a 2 N lateral force was applied to the center of the head part, the stress distribution and magnitude were analyzed using FEA. RESULTS: When the head part of the OMI was friction fitted (tapped into place) into the inserted screw part, the stress was uniformly distributed over the surface where the head part was inserted. The extent of the minimum principal stress suggested that the length of the head part was proportionate with the amount of stress to the cortical bone; the stress varied between 10.84 and 15.33 MPa. CONCLUSIONS: These results suggest that the stress level at the cortical bone around the OMI does not have a detrimental influence on physiologic bone remodeling.

Severe bidentoalveolar protrusion treated with lingual Biocreative therapy using palatal miniplate / 대한치과교정학회지

This case report describes the treatment of a 23-year, 8-month-old female patient with a Class II malocclusion who showed severe bidentoalveolar protrusion and anterior crowding. The treatment plan consisted of extracting all the first premolars, decrowding and en masse retraction of the upper six anterior teeth and lower anteriors. The upper C-plate placed in the midpalatal area combined with lingual sheath fixtures were used as substitutes for posterior anchorage teeth during upper anterior retraction. Preadjusted brackets (0.022-inch) were used for upper anterior decrowding. A 0.9 mm diameter stainless steel lever-arm soldered to the main arch wire facilitated controlled retraction of upper anteriors. The upper and lower dentition was detailed using a tooth positioner during the finishing stage. Correct overbite and overjet were obtained by decrowding and retraction of the upper six anterior teeth into their proper positions. Use of the C-plate and lingual appliances provided ideal anchorage to enhance the improvement in facial balance. The active treatment period was 19 months. The treatment result was stable 13 months after debonding.

Severe bimaxillary protrusion with adult periodontitis treated by corticotomy and compression osteogenesis / 대한치과교정학회지

This paper describes the case of a 50-year-old female with a Class II malocclusion who presented with severe bimaxillary protrusion and generalized alveolar bone loss due to adult periodontitis. The treatment plan consisted of extracting both upper and lower first premolars and periodontal treatment. Anterior segmental osteotomy (ASO) of the mandible and upper anterior segment retraction using compression osteogenesis after peri-segmental corticotomy (Speedy orthodontics) was performed. Correct overbite and overjet, facial balance, and improvement of lip protrusion were obtained. However, a slight root resorption tendency was observed on the lower anterior dentition. The active treatment period was 9 months and the results were stable for 27 months after debonding. This new type of treatment mechanics can be an effective alternative to orthognathic surgery.

Bone-implant contact and mobility of surface-treated orthodontic micro-implants in dogs / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to evaluate the mobility and ratio of the bone-implant contact (BIC) of a sandblasted, large grit and acid-etched (SLA) orthodontic micro-implant. METHODS: Ninety-six micro-implants (48 SLA and 48 machined) were implanted in the upper and lower buccal alveolar bone, and palatal bone of four beagle dogs. Two weeks after surgery, orthodontic force (150 - 200 g) was applied. Two beagles were sacrificed at 4-weeks and the other two at 12-weeks. Histomorphometric comparisons were made between the SLA experimental group and the machined micro-implant as a control group to determine the ratio of contact between the bone and implant. Micro-implant mobility was also evaluated using Periotest(R). RESULTS: Periotest values showed no statistically significant difference in the upper alveolar and palatal bone between groups except for the lower buccal area. BIC in the upper buccal area showed no significant difference between groups both at 4-weeks and 12-weeks. However, both the groups showed a significant difference in BIC ratio in the rest of the experimental areas between 4 weeks and 12 weeks. The experimental group showed active bone remodeling around the bone-implant interface compared to the control group. CONCLUSIONS: There were significant differences in the BIC and the Periotest values between the surface-treated and machined micro-implants according to bone quality in the early stage.

The effect of NaF on bone and tooth resorption around an anchor tooth during a rapid maxillary expansion procedure / 대한치과교정학회지

This study was undertaken to determine the effect of a 2.2 mg/Kg/day intraoral administration of NaF on the amount of root resorption and osteoclastic activity during or after a rapid maxillary expansion procedure. Ten puerile female dogs were divided into two groups: a control group and a NaF-treated group. A fixed type maxillary expansion device was delivered to all dogs. The appliance was activated twice daily throughout a 20-day period, causing a 5-mm expansion of maxillary bone. After the expansion procedure, the animals were sacrificed at days 0, 15, 30, 45, and 60 of the retention period. The buccal surface of the root of each maxillary canine was examined by means of a surface electron microscope (SEM). Using SEM, web-like resorption lacunae were observed on the bone or the tooth surface at the site of osteoclastic activity; these observations were verified by histological methods. No peculiar resorption lacunae were found in the apical tip of the roots of either the control group or the NaF-treated group animals. The NaF-treated retention group was found to have less resorption lacunae formation on day 45 and day 60. The preventative effect of NaF on resorption lacunae formation on the surface of the bone covering the anchor tooth was confirmed. Larger areas of resorption lacunae were found on the surface of the bone covering the canines in the control group animals, as compared to those of the NaF-treated group, especially on day 30 and day 60. Using SEM, the present study revealed a difference between the control group and the NaF-treated group in the prevalence and the size of the resorption lacunae formation on the cemental root surface. The preventative effect of NaF on bone resorption was confirmed. Further studies concerned with the optimum concentration of NaF that has an effect in vivo are necessary.

C-activator treatment for distalization of maxillary molars in Class II anterior deep bite malocclusion / 대한치과교정학회지

A modified removable appliance for molar distalization called C-activator was used in a 10-year old male patient with a Class II anterior deep bite malocclusion with upper arch discrepancy. The treatment plan involved correcting the Class II relationship, distalizing both upper first molars, and regaining space for the erupting canines. The C-activator, which was used for 6 months, consisted of a labial framework formed from .036-in stainless steel wire and an acrylic monobloc. Both the closed helices of the labial framework were compressed for reactivation during the C-activator treatment period. C-activator mechanics simultaneously achieved distalization of the upper first molars into their proper positions and repositioning of the mandible. After 21 months of treatment, the correct overbite and overjet was obtained and contributed to an improvement in facial balance. The treatment results were stable 6 months after debonding. Fabrication and placement of the new appliance and clinical procedures are detailed, and the treatment sequence and results of this case are presented as follows.

A study on treatment effects of Class III cases by second molar extraction / 대한치과교정학회지

This study aimed at investigating the skeletal, dentoalveolar, and soft tissue changes of Class III malocclusion cases treated by second molar extraction. The lateral cephalograms of 15 subjects with moderate Class III malocclusion by average ANB -1.4degrees and IMPA 85degrees were traced and the computerized superimposition of average craniofacial change was made. The data was gathered and statistically analyzed. The results were as follows: 1. Lower anterior facial height/anterior facial height increased by 0.6%(P<0.01), mandibular plane increased by 1.5degrees (P<0.05). 2. There was a slightly downward & backward rotation of the mandible. 3. Lower first molar tipped distally by 4.06mm(P<0.001), lower anterior teeth lingually tipped by 3.2degrees (P<0.05). 4. Retracted lower lip improved facial profile. This study may suggest that second molar extraction could be effective for a moderate Class III malocclusion to make distalization of the lower first molar easier and avoid severe lingual tipping of the lower incisor, if the lower third molar has a normal shape, good direction of eruption and adequate time for lower second molar extraction.

The experimental study of early loading on the Miniplate in the beagle dog / 대한치과교정학회지

Conventional osseointegrated titanium implants have many limitations; large size, limited location for placement of the implant, severity of the surgery, discomfort of initial healing, difficulty of oral hygiene and uncontrollable force direction. Recently titanium miniscrew and miniplate have been used for an alternative to conventional dental implant. But in relation to miniplate, miniscrew has disadvantages in that more potential inflammation, light orthodontic force application and limited orthodontic application. This study was conducted to evaluate the effectiveness of miniplate by observing the reactions of peri-implant tissues to early orthodontic and orthopedic loading of titanium miniplate. In four adult beagle dogs 10 miniplates were inserted into the alveolar bone using 20 osseointegrated titanium screws. 4 miniplates were placed in two dogs(dogA, B) and 6 miniplates in two dogs(dogC, D). In dogA, B miniplates were loaded with 200gm of force immediately after placement for 15 weeks. In dogC, D, miniplates were loaded with 400gm of force immediately after placement for 8 weeks. Miniplates of dogA were removed, dogA was healed for 4 weeks, and the area which was removed of miniscrew was examined. Following an observation period, the miniplates including miniscrews and the surrounding bone of dogB and dogC, D were removed, respectively. Undecalcified section along the long axis of miniscrews were made and the degree of osseointegration was examined under the light microscope. The results were as follows. 1. In the histologic features there was direct contact between bone and miniscrew in all groups except one, dogC control group. The loaded miniscrew demonstrated only a slight increase of the osseous proximaty when compared with unloaded miniscrew 2. There was no significant difference of the osseointegration of peri-miniscrew surface between dogB and dogC, D. But dogB showed slightly more increased bone apposition than dogC, D 3. The gingiva overlapping the miniplate and miniscrew showed no inflammatory sign in clinical and histological aspects. 4. The impared hard and soft tissues at the area which was removed of miniscrews showed good healing without inflammatory reaction. 5. The mobility showed slight increase in un-loaded miniplate but that was insignificant. Based on the results of this study, miniplate(C-tube(R)) can be used as a firm osseous orthodontic and orthopedic anchorage unit immediately after insertion.