Intrusion of overerupted molars by corticotomy and magnets

3D digital analysis of tooth movement with magnets and elastics in vitro

Objectives

Magnets have many advantages in orthodontics, and our previous studies confirmed their therapeutic potential through 3D-data analysis. The aim of this study was to compare tooth movements, including rotation, obtained via magnetic and elastic forces in crowded cases in vitro.

Methods

Typodont models mimicking a crowded case were prepared. In the magnetic force-driven orthodontics (MG) group, Nd-Fe-B magnets were attached to the labial surfaces from UR4 to UL4 for attracting force, and to UR6 and UL6 for repulsing force. For the elastic force-driven orthodontic (EL) group, brackets were placed on labial surfaces from UR2 to UL2 with power-chain elastics. A NiTi archwire was used in both groups. The models were 3D scanned before and after tooth movement and exported as STL files. The pre- and post-movement STL files were superimposed. The 3D coordinates of the measurement points of the crown and root apex were obtained, and tooth displacement, 3D movements (X, Y, and Z-axis), and rotation (yaw, pitch, and roll) were calculated. Two-tailed Student's t-test was performed for comparison of the results between MG and EL groups (n = 3).

Results

Overall, both groups indicated similar movement and rotation to achieve the planned arch form. In the crown movement and rotation, no significant differences were observed between MG and EL groups. However, in the root movement, there was a significant difference between MG and EL groups in X and Z axis for the canines.

Conclusions

Magnetic force-driven orthodontics demonstrated comparable results to elastics with less tipping movement, suggesting a potential future orthodontic modality.

Clinical significance

This in vitro study showed the potential of magnetic force for orthodontic application. The magnetic force-driven orthodontics might provide less tipping tooth movement compared to conventional methods, such as power chains, and could be a future technique for comprehensive orthodontic treatment.

An Interdisciplinary Management of Severe Facial Asymmetry Due to Hemifacial Microsomia

This case report outlines the importance of an interdisciplinary approach and a patient centric outcome for the treatment of facial asymmetry resulting from hemifacial microsomia. Different treatment modalities are available to treat asymmetries. However, the best treatment outcome can be achieved only when the treatment plan is individualized for every patient. This report portrays an adult patient with hemifacial microsomia, who had facial asymmetry from the level of supraorbital region with a Class II skeletal base. Orthodontic treatment, along with surgical management, was required to transform the patient into a symmetrical profile, which is esthetically pleasing. A sound knowledge of the various technologies and resources that are available to us and making the best use of it to bring out a drastic change in the patient's life. Combined effort of the orthodontists and oral surgeons are required to manage patient's with hemifacial microsomia that has caused the severe facial asymmetry. Moreover, special attention has to be given to a patient-centric outcome.

Magnetic extrusion technique for restoring severely compromised teeth: A case report

An orthodontic magnetic extrusion technique is described for the management of an extensively damaged maxillary premolar. A cylindrical neodymium-iron-boron (Nd₂Fe₁₄B) magnet was attached to the remaining tooth structure, and a second magnet was placed on a resin-bonded partial denture. A 4.5-mm extrusion was obtained after 3 adjustments, and the tooth was prepared with a 3-mm buccal and 2-mm lingual ferrule by following a biologically oriented preparation technique and restored with a monolithic zirconia crown. Eighteen months after completing the treatment, no evidence of soft tissue dehiscence, abnormal tooth mobility, endodontic failure, or root resorption was found.

Effect of Magnet Position on Tipping and Bodily Tooth Movement in Magnetic Force-Driven Orthodontics

The goal of our study is to launch magnetic force-driven orthodontics. This continuous study investigated the influence of magnet position on tipping and bodily tooth movement, using 3D printing technology and digital analysis. Orthodontic typodont models (TMs) for space-closure were 3D printed to mimic maxillary central incisors. Nd-Fe-B magnets were placed in the middle third (Model-M), and the cervical third (Model-C), of the tooth. TMs, before and after movement, were digitally scanned and superimposed. The 3D digital coordinates (X, Y, and Z axes), and rotations (yaw, pitch, and roll) of the tooth crown and root, were calculated and compared between the two magnet position settings. Model-M showed higher rates of movement, but more rotation than Model-C (p < 0.01). The root apex of Model-M moved in the opposite direction of the crown (R = −0.29), indicating tipping movement. In contrast, the crown and root apex moved in the same direction (R = 0.56) in Model-C, indicating bodily movement. These patterns were confirmed in a typodont model of a moderate crowding case. The results validated that modifying the magnet position increased the amount of bodily tooth movement, and decreased rotation/tipping in an ex vivo setting.

Selective osteotomy-assisted molar uprighting and simultaneous ridge augmentation for implant site development

Orthodontic treatment to upright an inclined molar adjacent to an edentulous space is often necessary before implant placement. The implant site may also require a ridge augmentation if the bony volume is not sufficient. The time required for both treatment steps can be lengthy and can discourage patients from accepting dental implants. This case report presents a novel interdisciplinary approach to implant site development. Selective osteotomy and simultaneous ridge augmentation were performed on the bilateral mesially inclined second molars before orthodontic uprighting. The severely inclined second molars were uprighted in 5 months, and the enhanced implant sites were ready for implant placement without complications. A finite element analysis revealed that the osteotomy partially affected the biomechanical responses of the dentoalveolar structures during molar uprighting.

An archwire for non-invasive improvement of occlusal cant and soft tissue chin deviation

Nonsurgical improvement of an occlusal cant, lip cant, and soft tissue chin deviation has been considered not possible merely through orthodontic treatment without surgical intervention. The purpose of this report was to illustrate a possible new field in orthodontics for a non-invasive improvement of the occlusal cant and soft tissue chin deviation through orthodontic approach by an innovative orthodontic archwire (Yin-Yang wire) and the others.

Maxillary posterior intrusion with corticotomy-assisted approaches with zygomatic anchorage-a finite element stress analysis

Background

Anterior open bite is one of the most difficult malocclusions to treat and maintain in orthodontics. An effective treatment approach to correct anterior open bite is the intrusion of maxillary posterior teeth. The aim of this study was to evaluate the effects of corticotomy-assisted posterior maxillary intrusion with zygomatic anchorage by using finite element stress analysis.

Methods

An acrylic bite block on the posterior teeth including two transpalatal arches were modeled and 1.96 N intrusive force was loaded. Three scenarios were set, first with no subapical corticotomy, second with buccal, and third with both buccal and palatal corticotomies. The stress distributions along the cortical, cancellous bone surfaces, and dental structures were assessed by finite element stress analysis.

Results

Stress distributions over cortical and cancellous bones were commonly located at the inferior curvature of the zygomatic buttress area and posterior teeth for all scenarios. Stress values above the apices of anchor teeth were decreased for both corticotomy scenarios. Increased stress distributions were observed in cancellous bone around corticotomy regions. Despite the acrylic appliance and transpalatal arches, the stresses along the posterior teeth were not uniform. The apical third of the first molar mesiobuccal apex showed the highest stress values in all scenarios.

Conclusions

Corticotomy-assistance effected biomechanical responses of dentoalveolar structures during maxillary posterior intrusion. There was no apparent difference for the stress levels of the root apices between corticotomy scenarios, pointing out that only buccal corticotomy may be a better option in corticotomy-assisted maxillary intrusion.

Macroscopic and microscopic evaluation of flapless alveolar perforations on experimental tooth movement

Objective:

The aim of this study was to evaluate a flapless surgical technique as an alternative to traditional alveolar corticotomy used to accelerate orthodontic tooth movement (OTM).

Methods:

To induce OTM in Wistar rats, 40 cN of orthodontic force were applied to the maxillary left first molars. Forty rats were distributed into control groups (CG1, CG3, CG7 and CG14) and experimental groups (n= 5), in which alveolar perforations were made using a spear-shaped guide bur (EG1, EG3, EG7, EG14). Euthanasia dates were set at 1, 3, 7 and 14 days, respectively, after tooth movement began. The amount of OTM was measured with a caliper, and osteoclasts present in the periodontal ligament of the mesial root of the moved tooth were counted by means of histological evaluation (tartrate-resistant acid phosphatase staining, TRAP).

Results:

Although there was no difference in the amount of OTM within subgroups of corresponding experimental periods (p> 0.05), when EG14 and CG14 were compared, a larger number of osteoclasts was counted in the experimental group (p< 0.00).

Conclusion:

The authors concluded that flapless cortical alveolar perforations led to more intense osteoclastic activity on the fourteenth day; nevertheless, no evidence of accelerated OTM could be noted.

Mandibular Molar Intrusion with a Modified Lingual Arch

Intrusion of the supra erupted molar is one of the most difficult treatment. Supra eruption is common in a mutilated dentition. This article describes an effective way to bring about intrusion of supra erupted molars.

[Effectiveness of selective alveolar decortication in accelerating orthodontic treatment: a systematic review]

INTRODUCTION

The number of scientific publications on accelerating orthodontic treatment, and especially surgical alveolar corticotomies techniques, has grown exponentially over the years. The objective of this systematic literature review was to assess the effectiveness of these corticotomies basing on human studies.

MATERIAL AND METHOD

The review was conducted from Medline and Web of Science Core Collection to identify prospective controlled clinical trials with duration of orthodontic treatment or the tooth movement rate for primary endpoint.

RESULTS

Eleven studies respected all inclusion criteria. Six investigated the duration of treatment and found shorter values in experimental group than in control group, with a gain of 8 to 34 weeks. Five investigated the tooth movement rate and found 2.3 times higher values on average during the first month in experimental groups, 1.9 times during the second and third months, and 1.3 times during the fourth month. The technique also seemed to decrease the risk of root resorption and improve molar anchorage. Moreover, it exhibited good periodontal tolerance.

CONCLUSION

Current literature highlights the effectiveness of surgical decortications during the first three to four months after surgery. Longer prospective studies are needed to assess their long term effects.

[Collaboration between periodontics and orthodontics: interest of alveolar corticotomies and piezocision. Review of literature]

INTRODUCTION

Orthodontics in adults must adapt to certain particularities especially related to the decrease or absence of growth and the prevalence of periodontal damage in this population. This review of the literature aims to assess the effects of alveolar corticotomies on accelerating or facilitating tooth movements in different types of orthodontic movements, to compare results obtained by classical technique with those obtained by piezocision and analyze their impact on periodontal tissues in the long term.

MATERIAL AND METHODS

Research was performed with Medline, Embase and Cochrane databases, beginning in January 2000. Every study, selected through its title and abstract, was then evaluated through its full content. A total of 65 studies were included.

RESULTS

All studies showed that corticotomies temporarily facilitate accelerated orthodontic tooth movement, with minimal complications. No periodontal lesion, loss of pulpal vitality or severe root resorption were reported.

DISCUSSION

Only a few studies have examined control groups treated with conventional orthodontics. Corticotomy allows temporary acceleration of orthodontic tooth movement. Piezocision is less invasive and performed in certain indications; it also lightens the postoperative complications. However, the fact that using alveolar corticotomies significantly decreases the treatment time remains uncertain, due to the lack of significant data. Further prospective randomized clinical studies are necessary to analyze more precisely the decrease in the overall treatment time, improved periodontal support and stability of orthodontic treatment results in the long term following the alveolar corticotomies.

Prevalence of Malocclusion in 3- to 5-Year-Old Children in Shanghai, China

The aim of the present study was to obtain the prevalence of malocclusions in preschool children in Shanghai, China. A cross-sectional survey was conducted among 2335 children aged 3-5 years from kindergartens. Several occlusal parameters were clinically assessed, including second deciduous molar terminal plane, canine relationship, degree of overjet and overbite, anterior and posterior crossbite, and the presence or absence of physiologic spaces and crowding. All parents of subjects were asked to fill in the oral health knowledge questionnaires. The prevalence of malocclusion in primary dentition in Shanghai was 83.9%, and no significant differences were found in genders. Data showed that the prevalence of deep overbite (63.7%) was the highest in children with malocclusion, followed by deep overjet (33.9%), midline deviation (26.6%), anterior crossbite (8.0%) and anterior crowding (6.5%). The results revealed a high prevalence of malocclusion in primary dentition in children aged 3-5 years old of Shanghai, especially in vertical anomalies. The need for preventive orthodontic therapy is extremely desired and oral health education about malocclusion should be strengthened.

Effects of a novel magnetic orthopedic appliance (MOA-III) on the dentofacial complex in mild to moderate skeletal class III children

Introduction

The objective of this study was to evaluate the changes of skeletal and dental structures in mild to moderate skeletal Class III children following the use of a new magnetic orthopedic appliance (MOA-III).

Methods

A total of 36 patients (14 boys and 22 girls, mean age 9 years and 5 months) who presented with a mild to moderate skeletal Class III jaw discrepancy were treated with MOA-III. Another group of 20 untreated patients (9 boys and 11 girls, mean age 9 years and 2 months) with the same level of deformity served as the control group. The average treatment time was 6.6 months. Radiographs were taken at the same time intervals for both groups. A paired t test was used to determine the significant differences before and after treatment, and a two-sample t test was used to analyze the differences between the treatment and control groups.

Results

The anterior crossbite in all subjects was corrected after MOA-III therapy. The maxillomandibular relationship showed favorable changes (ANB, Wits, overjet increased significantly, P < 0.001). The maxilla was anteriorly positioned (SNA, ptm-A, ptm-S increased significantly, P < 0.001) with clockwise rotation (PP-FH increased, P < 0.001). The mandible showed a slight downward and backward rotation (SNB decreased, P < 0.05, MP-SN, Y-axis increased, P < 0.05). The length of the mandibular body showed no significant changes (Go-Pg, P > 0.05). Significant upper incisor proclination and lower incisor retroclination were observed (UI-NA increased, P < 0.001, LI-NB, FMIA decreased, P < 0.001). The upper lip moved forward, and the lower lip moved backward (UL-EP increased, P < 0.001, LL-EP decreased, P < 0.05). In the control group, most of the parameters showed normal growth, except for some unfavorable mandibular skeletal and soft tissue changes (Go-Pg, Go-Co, MP-SN, N′-SN-Pg′ increased, P < 0.001). Significant positive changes were induced with the MOA-III appliance compared to the untreated group.

Conclusions

The MOA-III was effective for the early treatment of a mild to moderate Class III malocclusion in children.

A Precise Method of Measuring Simultaneous Intrusion and Uprighting of Mandibular Molar Using Denta Scan - A Case Report

A commonly encountered problem in prosthetic dentistry is the supra eruption of teeth due to absence of opposing teeth. Consequently, replacement of the missing teeth with prosthesis becomes difficult due to lack of vertical dimension of the edentulous area. This article describes the space regaining procedure in a 14-year-old female patient who wanted a fixed prosthesis for her missing maxillary 1st molar. On examination, it was observed that mandibular 1st molar had supraerupted and tipped lingually. After considering the various treatment modalities it was decided to simultaneously intrude and upright the mandibular molar using a mini-implant. The precise measurements of intrusion and uprighting were done using Dentascan software. Intrusion of 1.8mm and buccolingual uprighting of 2.3mm was achieved in 45 days. The mini-implant is an efficient non-compliance device to intrude and upright the tooth simultaneously. Dentascan is an accurate and very precise method of measuring the intrusion and uprighting of teeth.

Intrusion of supraerupted maxillary molar using a high interim restoration on the defective opposing tooth: a clinical report

Wear, extraction, or fracture of all or part of a mandibular first molar can lead to the supraeruption of the opposing maxillary molar, resulting in occlusal interference and lack of restoration space. This report describes a method to gain sufficient vertical space for permanent restoration. A direct composite resin restoration was placed on the occlusal surface of a lower molar, intentionally making the interim restoration high and intruding the maxillary molar. After 6 weeks, the extruded tooth returned to the desired position, and functional occlusion was restored, enabling a ceramic restoration on the mandibular molar. No marked adverse sensory reaction was reported in this therapeutic process, and no deleterious signs were detected in the teeth, periodontium, or temporomandibular joints. The simple treatment type was effective, noninvasive, and time saving, while also preserving maximum tooth structures.

Correction of facial asymmetry and maxillary canting with corticotomy and 1-jaw orthognathic surgery

Although 2-jaw orthognathic surgery is a typical recommendation for the treatment of facial asymmetry, another good treatment alternative is maxillary corticotomy with temporary skeletal anchorage devices followed by mandibular orthognathic surgery. The corticotomy procedure described here can achieve unilateral molar intrusion and occlusal plane canting correction with potentially fewer complications than 2-jaw orthognathic surgery. The approach allows movement of dentoalveolar segments in less time than with conventional dental intrusion using temporary skeletal anchorage devices. A 2-jaw asymmetry with occlusal plane canting might be corrected using maxillary corticotomy and mandibular orthognathics rather than 2-jaw orthognathics. Two patients with facial asymmetry are presented here. In each one, the maxillary cant was corrected over a period of 2 to 3 months with 3.5 mm of intrusion of the unilateral buccal segment. After the preorthognathic cant correction, orthognathic surgery was done to correct the mandibular asymmetry.

Dental movement acceleration: Literature review by an alternative scientific evidence method

The aim of this study was to analyze the majority of publications using effective methods to speed up orthodontic treatment and determine which publications carry high evidence-based value. The literature published in Pubmed from 1984 to 2013 was reviewed, in addition to well-known reports that were not classified under this database. To facilitate evidence-based decision making, guidelines such as the Consolidation Standards of Reporting Trials, Preferred Reporting items for systematic Reviews and Meta-analyses, and Transparent Reporting of Evaluations with Non-randomized Designs check list were used. The studies were initially divided into three groups: local application of cell mediators, physical stimuli, and techniques that took advantage of the regional acceleration phenomena. The articles were classified according to their level of evidence using an alternative method for orthodontic scientific article classification. 1a: Systematic Reviews (SR) of randomized clinical trials (RCTs), 1b: Individual RCT, 2a: SR of cohort studies, 2b: Individual cohort study, controlled clinical trials and low quality RCT, 3a: SR of case-control studies, 3b: Individual case-control study, low quality cohort study and short time following split mouth designs. 4: Case-series, low quality case-control study and non-systematic review, and 5: Expert opinion. The highest level of evidence for each group was: (1) local application of cell mediators: the highest level of evidence corresponds to a 3B level in Prostaglandins and Vitamin D; (2) physical stimuli: vibratory forces and low level laser irradiation have evidence level 2b, Electrical current is classified as 3b evidence-based level, Pulsed Electromagnetic Field is placed on the 4^th level on the evidence scale; and (3) regional acceleration phenomena related techniques: for corticotomy the majority of the reports belong to level 4. Piezocision, dentoalveolar distraction, alveocentesis, monocortical tooth dislocation and ligament distraction technique, only had case series or single report cases (4^th level of evidence). Surgery first and periodontal distraction have 1 study at level 2b and corticision one report at level 5. Multiple orthodontic acceleration reports on humans were identified by an alternative evidence level scale, which is a simple and accurate way of determining which techniques are better and have a higher rate of effectiveness. The highest level of evidence for a specific procedure to accelerate orthodontic dental movement up to October 2013 was surgery first followed by low level laser application, corticotomy and periodontal distraction located on level 2, recommendation grade b from this proposed scientific evidence-based scale.

Nonextraction treatment of severe crowding with the aid of corticotomy-assisted orthodontics

This paper illustrates the combined nonextraction orthodontic treatment with the corticotomy technique in an adult patient (age: 25 years and 3 months) with severely crowded arches to accelerate tooth movement and shorten the treatment time. Both her upper lateral incisors were congenitally absent and both upper central incisors' roots were short. Initial fixed orthodontic appliances (bidimensional) were bonded and one week later buccal and lingual corticotomy with alveolar augmentation procedure in the maxilla and mandible was performed. Orthodontic activation to level and align and unravel the crowding was performed every two weeks. The total treatment time was 8 months with no adverse effects observed at the end of active treatment. The addition of the decortication procedure to the conventional orthodontic therapy decreased the duration of treatment significantly. Successful alignment of both arches with ideal overbite and overjet as well as adequate occlusion was achieved.

[Accelerated tooth movement by alveolar corticotomy or piezocision]

The relatively recent introduction of corticotomies and piezocision has made it possible for orthodontists to accelerate tooth movement and thereby to shorten the length of orthodontic treatment. Specialists emphasizing a mechanistic concept have been debating the underlying basic biological mechanics of these new therapeutic tools with opposing specialists who support a biological conception. Our analysis of different publications on the subject suggests that the biological explanation, with its emphasis on the Regional Acceleratory Phenomenon (RAP), is correct. However, the majority of studies in this field are not based on the principle of evidence based medicine (EBM).

Orthodontic treatment of an anterior openbite with the aid of corticotomy procedure: Case report

This case report illustrates the orthodontic treatment combined with the corticotomy technique in an adult patient to accelerate tooth movement and shorten the treatment time. The patient was a 22-year-old woman with an anterior open bite and flared and spaced upper and lower incisors. First, fixed orthodontic appliances (bidimensional edgewise brackets) were bonded, and a week later buccal and lingual corticotomy with alveolar augmentation procedure in the maxillary arch from the first molar to the contralateral first molar, and from canine to canine in the mandibular arch was performed. Orthodontic therapy proceeded with frequent activation of the appliances to retract the incisors every 2 weeks. The total treatment time was 5 months and no adverse effects were observed at the end of active treatment. The addition of the decortication procedure to the conventional orthodontic therapy decreased the duration of treatment significantly. Successful closure of the anterior open bite with adequate overbite and interdigitation of the teeth were achieved.

Corticotomy-assisted orthodontic treatment: review

Corticotomy-assisted orthodontic treatment is an established and efficient orthodontic technique that has recently been studied in a number of publications. It has gradually gained popularity as an adjunct treatment option for the orthodontic treatment of adults. It involves selective alveolar decortication in the form of decortication lines and dots performed around the teeth that are to be moved. It is done to induce a state of increased tissue turnover and a transient osteopenia, which is followed by a faster rate of orthodontic tooth movement. This technique has several advantages, including faster tooth movement, shorter treatment time, safer expansion of constricted arches, enhanced post-orthodontic treatment stability and extended envelope of tooth movement. The aim of this article is to present a comprehensive review of the literature, including historical background, contemporary clinical techniques, indications, contraindications, complications and side effects.

Corticotomias alveolares na Ortodontia: indicações e efeitos na movimentação dentária

INTRODUÇÃO: a busca pelo aumento na eficiência dos tratamentos ortodônticos é uma constante em diversas áreas da Ortodontia atual. A realização de corticotomias alveolares pouco antes da aplicação de forças ortodônticas vem sendo sugerida como uma forma de potencializar a movimentação dentária e, consequentemente, o tratamento ortodôntico como um todo. OBJETIVO: o presente artigo revê a perspectiva histórica dessa abordagem terapêutica, apresenta e ilustra com casos clínicos suas principais indicações e, por fim, discute os fundamentos biológicos que justificam sua utilização.

Clinical application of accelerated osteogenic orthodontics and partially osseointegrated mini-implants for minor tooth movement

INTRODUCTION

This article illustrates a new treatment system combining accelerated osteogenic orthodontics and osseointegrated mini-implants for minor tooth movement in severely compromised conditions. The procedures, advantages, efficacy, and indications of this method are discussed.

METHODS

Three patients who needed minor tooth movement and orthodontic mini-implant treatment were recruited to use this combined technique; 1 required molar intrusion, and 2 required molar uprighting. C-Implant (diameter, 1.8 mm; length, 8.5 mm) were placed, and, after 5 weeks of healing, decortication of bone was performed near the malpositioned teeth by using a low-speed round bur. Bleeding was controlled, and the bone graft material was placed into the decorticated area. After the flap was secured, an immediate strong orthodontic force from the C-implant was applied to the teeth to start rapid tooth movement.

RESULTS

Only a few orthodontic attachments were necessary, and the teeth moved rapidly to a good occlusal relationship without root resorption.

CONCLUSIONS

The combination of accelerated osteogenic orthodontics and a partially osteointegrated mini-implant (C-Implant) was a safe and effective treatment choice. The C-implant's surface allows partial osseointegration, so it can resist a force moment without loosening and withstand the heavy forces associated with the accelerated osteogenic orthodontics protocol.

Intramaxillary and intermaxillary absolute anchorage with an endosseous dental implant and rare-earth magnets

This case report describes the management of a partially edentulous adult with a severe deepbite malocclusion and a collapsed buccal segment because of supraeruption of the maxillary second and third molars. The treatment involved placement of an endosseous dental implant to achieve absolute intermaxillary and intramaxillary anchorage. Rare-earth magnets embedded in acrylic bite-blocks were used to intrude the supraerupted maxillary molars on the right side. After use as an anchorage device, the implant was restored and brought into occlusion. Good occlusal and esthetic results were achieved with this cost-effective treatment.

Osteotomy assisted maxillary posterior impaction with miniplate anchorage

This case report presents orthodontic treatment with miniplate anchorage accelerated by osteotomy-assisted maxillary posterior impaction in a severe open bite case. A 14-year-old girl with a severe anterior open bite was treated by intrusion of the maxillary posterior teeth. A segmental osteotomy was applied, and the miniplates were fixed to the zygomatic buttress area. The intrusive force was applied with nickel-titanium closed coil springs using a force of 250 g between the miniplates and the upper first and second molar buccal tubes. The intrusion was completed 2.5 months after osteotomy. The treatment was continued with the fixed orthodontic appliances and completed after 12 months. At the end of treatment, optimal occlusion and the correction of the anterior open bite were achieved. The maxillary molars were impacted 4.0 mm, and the mandibular plane showed a counterclockwise autorotation of 3.0 degrees . The results showed that osteotomy-facilitated orthodontic treatment clearly reduced the treatment time and had no adverse effects. In conclusion, this one-stage osteotomy technique can be an effective option to help molar intrusion in severe open bite cases.

Intrusion of overerupted molars by corticotomy and orthodontic skeletal anchorage

This article describes the orthodontic treatment of a 26-year-old female patient with overerupted left maxillary molar teeth. Her chief complaint was that the maxillary left first and the second molar intruded into the space required for the mandibular left first and the second molars, preventing prosthodontic treatment. The authors performed a corticotomy and used orthodontic skeletal anchorage with a miniplate and orthodontic miniscrews with a head modified to provide a specially designed hook. With this approach, they were able to achieve a sufficient amount of molar intrusion without discomfort, root resorption, or extrusion of the adjacent teeth. The first molar was intruded 3.0 mm and second molar was intruded 3.5 mm during 2 months of treatment. These results have been maintained for 11 months.

[Alveolar osteotomy and rapid orthodontic treatments]

When combined with orthodontics, selective periodontal decortication has been shown to be clinically effective in eliminating severe malocclusions three to four times more rapidly than conventional orthodontic treatment. Our technique combines surgical scarring of the cortical bone on both labial and lingual sides of the teeth to be moved, with an augmentation graft to increase alveolar volume. Alveolar spongiosa undergoes rapid transformation as the body attempts to heal the wounds to the cortices resulting in marked tissue turnover. The patient is seen every two weeks and most cases are completed within six months of orthodontic treatment. Moreover, this technique significantly expands the scope of treatment in resolving many skeletal problems such as openbites and severe maxillary constrictions, conditions typically relegated to orthognathic surgery. Clinical outcomes research has shown that the immediate post treatment results settle better during retention and that the long term results become more stable. These facts are likely due to the high tissue turnover induced by decortication as well as the thicker cortical bone resulting from the augmentation grafting.

Acceleration of orthodontic tooth movement by alveolar corticotomy in the dog

INTRODUCTION

Tooth movement and alveolar bone reaction after corticotomies have not been thoroughly examined. In this study, the effects of corticotomies on orthodontic tooth movement and alveolar bone reaction were investigated in dogs.

METHODS

Corticotomies were performed on the cortical bone of the mandibular left third premolar region in 12 male adult beagles. The third premolars on the left experimental side and on the right sham side were moved mesially with a continuous force of 0.5 N.

RESULTS

Tooth movement velocities from 0 to 1 week and from 1 to 2 weeks after the corticotomies were significantly faster on the experimental side than on the sham side. Hyalinization of the periodontal ligament appeared only at 1 week after the corticotomies on the experimental sides, whereas it was observed from 1 to 4 weeks after the corticotomies on the sham sides. Tartrate-resistant-acid-phosphatase positive cells of the experimental side tended to work vigorously at an early time on the alveolar wall and in the bone marrow cavities.

CONCLUSIONS

Orthodontic tooth movement increased for at least 2 weeks after the corticotomies. This might be brought about by rapid alveolar bone reaction in the bone marrow cavities, which leads to less hyalinization of the periodontal ligament on the alveolar wall.

Correction of a canted occlusal plane with miniscrews in a patient with facial asymmetry

The inability of orthodontists to change the cant of the maxillary occlusal plane without surgical intervention is a limitation of orthodontic treatment. LeFort I osteotomy with asymmetric maxillary impaction is often used to correct this problem. However, canting caused by extruded teeth can be corrected easily with normal orthodontic appliances and skeletal anchorage. The correction occurs through intrusion of the extruded teeth on 1 side of the maxilla, thereby avoiding a more aggressive surgical approach. A 22-year-old Korean man with facial asymmetry and mandibular prognathism treated in this manner showed the possibility of correcting occlusal plane canting with miniscrews.

Interdisciplinary Management of Dental Implant Patient: A Case Report

Maxillary molars can over-erupt when their antagonists are lost and there are no replacements. When the opposing molars severely extrude into the edentulous space, it is difficult to replace the missing teeth with either fixed or removable prostheses. We present the following case report, providing a solution for this type of problem. A two-stage posterior subapical osteotomy was used to reestablish the intermaxillary space. Following orthodontic treatment and implant placement, the patient regained occlusal harmony and normal masticatory function.