Accelerated decompensation of mandibular incisors in surgical skeletal Class III patients by using augmented corticotomy: A preliminary study

A nomogram prediction of gingival recession in mandibular incisors of orthodontic-orthognathic treated skeletal class III malocclusion with or without PAOO: A retrospective cohort study

Background

To assess the alterations in gingival thickness and the occurrence gingival recession subsequent to orthodontic-orthognathic treatment of mandibular incisors in skeletal Class III and identify risk factors associated with gingival recession.

Methods

In this retrospective cohort study, we enrolled 33 patients exhibiting skeletal Class III malocclusion, totaling 131 mandibular incisors, who were undergoing orthodontic- orthognathic treatment that did not involve extraction of mandibular teeth. The subjects were categorized into surgery group (S; n = 17; ANB = -5.55 ± 3.26; IOFTN = 4.60 ± 0.51, scores ranging: 4.3-5.3) and non-surgery group (NS; n = 16; ANB = -3.00 ± 4.08; IOFTN = 4.63 ± 0.50, scores ranging: 4.3-5.4), based on if they had history of Periodontally Accelerated Osteogenic Orthodontics surgery (S) or not (NS). Patients in S group received orthognathic surgery about 1-1.5 years after Periodontally Accelerated Osteogenic Orthodontics surgery. Alterations in gingival thickness, gingival recession, and keratinized gingival width were compared before and after orthodontic-orthognathic treatment. Logistic regression analysis was used to construct a gingival recession prediction model and draw nomograms.

Results

After orthodontic-orthognathic treatment, the gingival thickness and keratinized gingival width in NS group decreased by 0.15 ± 0.21 mm and 0.74 ± 0.91 mm, whereas those in the S group increased by 0.32 ± 0.28 mm and 2.09 ± 1.51 mm (P < 0.05). After orthodontic-orthognathic, the percentage of gingival recession increased by 47.62 % in NS group, which was 14.77 times that of S group (P < 0.05). Multivariate regression analysis indicated that skeletal Class III patients with a gingival thickness below 0.72 mm, an alveolar bone height exceeding 2.36 mm, and an alveolar bone thickness under 0.45 mm might be at elevated risk for developing gingival recession following orthodontic - orthognathic therapy.

Conclusions

Drawing on the findings of our investigation, we concluded the risk of gingival recession of mandibular anterior teeth increased after orthodontic-orthognathic treatment in skeletal Class III, whereas Periodontally Accelerated Osteogenic Orthodontics surgery could significantly improve the periodontal phenotype and prevent gingival recession.

Association between alveolar bone height changes in mandibular incisors and three-dimensional tooth movement in non-extraction orthodontic treatment with Invisalign

OBJECTIVE

The purpose of this study was to investigate associations between alveolar bone height changes on the labial and lingual sides in mandibular incisors and three-dimensional orthodontic tooth movement, involving apex displacement, tooth inclination, and angulation.

MATERIALS AND METHODS

The samples consisted of 43 adult patients treated with Invisalign aligners. All subjects were skeletal Class I patients without extraction in mandible. Pre-treatment and post-treatment cone-beam computed tomographic images were obtained to measure labial and lingual alveolar bone height and bone thickness at apex level in four mandibular incisors. An x, y, z coordinate system, superimposing on mandibular body, was established to analyse three-dimensional apex movement and tooth inclination and angulation changes. Multiple linear regression was applied to identify the determining factors of marginal bone changes during orthodontic treatment.

RESULTS

Three directions of apex movement (anteroposterior, vertical, transverse) significantly associated with alveolar bone height changes. Inclination changes had a strong effect on lingual marginal bone, while tooth angulation had no significant effect on alveolar bone height. Incisors with lingual bodily movement were more susceptible to lingual marginal bone recession compared with lingual tipping movement.

CONCLUSIONS

Alveolar bone height changes on the labial and lingual sides were associated with three-dimensional apex movement, inclination changes, and movement patterns. Appropriate tooth movement should be considered to avoid excessive marginal bone loss around mandibular incisors.

Periodontal soft tissue increase induced by periodontally accelerated osteogenic orthodontics surgery

Objectives

To quantitatively assess periodontal soft tissue changes, including gingival thickness and keratinized gingiva width after periodontally accelerated osteogenic orthodontics (PAOO) surgery by digital measurements. 

Methods

This study enrolled 15 maxillaries with 89 anterior teeth and 16 mandibles with 94 anterior teeth from Chinese adult patients with skeletal Angle Class III malocclusion for whom PAOO surgery was proposed during orthodontic treatment. Intraoral scanning and cone beam computed tomography (CBCT) examinations were performed before PAOO surgery and 6 months after the surgery. Keratinized gingiva width was measured on the digital model acquired by intraoral scanning. The gingival thickness was measured using a digital three-dimensional (3D) model based on the combination of digital intraoral scanning and CBCT data.

Results

The mean gingival thickness before surgery was 0.91 ± 0.32 mm and 1.21 ± 0.38 mm at 6-month after PAOO. Patients showed periodontal soft tissue increase with a mean gingival tissue gain of 0.30 ± 0.33 mm. At 1 mm, 2 and 3 mm apical to cemento-enamel junction (CEJ) levels, the gingival thickness increase of the mandible was higher than that of the maxilla (0.38 ± 0.30 mm vs. 0.24 ± 0.31 mm, 0.43 ± 0.35 mm vs. 0.26 ± 0.41 mm, 0.36 ± 0.27 vs. 0.25 ± 0.32 mm, respectively, all P < 0.05). Moreover, the sites of gingival thickness ≤ 1 mm before surgery showed more tissue gain than the sites > 1 mm (0.36 ± 0.32 mm vs. 0.18 ± 0.31 mm, P < 0.001). The mean keratinized gingiva width at T0 was 3.88 ± 1.22 mm, and increased 1.05 ± 1.24 mm 6 months after PAOO surgery. Moreover, a digital 3D model for gingival thickness measurement based on the combination of digital intraoral scanning and CBCT displayed high reliability and accuracy with an intra-class correlation coefficient (ICC) of 0.897.

Conclusion

PAOO could improve an insufficient quantity of periodontal soft and hard tissues in patients with skeletal Angle Class III malocclusion, including the gingival thickness and keratinized gingiva width. A digital 3D model based on the combination of digital intraoral scanning and CBCT data could provide a new digital measurement of gingival thickness with high accuracy and reliability.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02566-8.

Surgical Camouflage as a Solution for Complete Decompensating Failures: An Interesting Experience With Class III Case Scenarios

Dental compensations are an integral part of skeletal malocclusions. Failure to achieve optimal decompensation may lead to compromised surgical movements, thereby resulting in sub-optimal occlusion and soft tissue profile. Hence the mandibular subapical osteotomy was chosen as a minimalistic surgical alternative to the traditional combination of Le Fort 1 and bilateral sagittal split osteotomy. The choice was made by prioritizing soft tissue considerations, which offered the probability of a better post-treatment outcome. This paper highlights two such challenging case scenarios where the surgical plan was modified in accordance with the soft tissue as the primary objective.

Periodontal soft- and hard-tissue changes after augmented corticotomy in Chinese adult patients with skeletal Angle Class III malocclusion: A non-randomized controlled trial

BACKGROUND

To investigate soft- and hard-tissue changes after augmented corticotomy in Chinese adult patients with skeletal Angle Class III malocclusion.

METHODS

This non-randomized controlled trial included 357 anterior teeth from 30 Chinese adult patients with skeletal Angle Class III malocclusion for whom the proposed treatment was augmented corticotomy. Jaws receiving surgery were allocated to a test group (S, surgical group, n = 47) and jaws not receiving surgery were allocated to a control group (NS, non-surgical group, n = 13). Changes in the periodontal biotype, width of the keratinized gingiva (WKG), and labial and lingual horizontal bone thicknesses (BTs) were compared 6 months after surgery by univariate and multivariate analyses.

RESULTS

After adjustment for confounding variables, average gains of 0.473 mm in the WKG and 0.649 mm in the labial BT were found in the S group relative to the NS group (P <0.05). The odds of transition from a thin periodontal biotype to a thick biotype in the S group were about 230 times those in the NS group, and the odds of the reverse biotype transition in the NS group were about 83 times those in the S group (P <0.05).

CONCLUSIONS

Within the limitations of the present study, augmented corticotomy is a promising approach to improve insufficient periodontal soft and hard tissues in Chinese adult patients with skeletal Angle Class III malocclusion.

Is periodontal phenotype modification therapy beneficial for patients receiving orthodontic treatment? An American Academy of Periodontology best evidence review

BACKGROUND

Orthodontic treatment can greatly impact the periodontium, especially in dentitions with a thin periodontal phenotype. Orthodontic tooth movement can result into iatrogenic sequelae to these vulnerable anatomic conditions, such as development and exacerbation of bony dehiscence or fenestration defects, which can manifest loss of periodontal support and gingival recession (GR). This systematic review aimed to investigate whether periodontal phenotype modification therapy (PhMT) involving hard tissue augmentation (PhMT-b) or soft tissue augmentation (PhMT-s) has clinical benefits for patients undergoing orthodontic treatment.

METHODS

An electronic search was performed in two major databases for journals published in English language from January 1975 to January 2019 and a hand search of printed journals was also performed to identify human clinical trials reporting clinical and radiographic outcomes of patients receiving orthodontic treatment with or without hard and soft tissue augmentation procedures. Data were extracted and organized into tables for qualitative assessment.

RESULTS

Eight studies were identified evaluating the outcomes of PhMT in patients undergoing orthodontic therapy. Six studies evaluated patients receiving PhMT-b via corticotomy-assisted orthodontic therapy (CAOT) and simultaneous bone augmentation while the other two received PhMT-s before tooth movement. No studies investigated PhMT-b alone without CAOT and most studies focused on the mandibular anterior decompensation movements. There was high heterogeneity in the study design and inconsistency of the reported outcomes; therefore, a meta-analysis was not performed. Evidence at this moment supports CAOT with hard tissue augmentation accelerated tooth movement. However, only two studies provided direct comparison to support that CAOT with PhMT-b reduced the overall treatment time compared with conventional orthodontic treatment. No periodontal complications or evidence of severe root resorption were reported for both groups. Four studies provided radiographic assessment of the PhMT-b and demonstrated increased radiographic density or thicker facial bone after the treatment. Two studies reported an expanded tooth movement. One study reported an increase in keratinized tissue width post-CAOT plus PhMT-b, while another study with a 10-year follow-up showed a lower degree of relapse using the mandibular irregularity index when compared with conventional tooth movement alone. Two studies examined the effect of PhMT-s before orthodontic treatment. Unfortunately, no conclusions can be drawn because of the limited number of studies with contradicting outcomes.

CONCLUSIONS

Within the limited studies included in this systematic review, PhMT-b via particulate bone grafting together with CAOT may provide clinical benefits such as modifying periodontal phenotype, maintaining or enhancing facial bone thickness, accelerating tooth movement, expanding the scope of safe tooth movement for patients undergoing orthodontic tooth movement. The benefits of PhMT-s alone for orthodontic treatment remain undetermined due to limited studies available. However, PhMT-b appears promising and with many potential benefits for patients undergoing orthodontic tooth movement. There is a need for a higher quality of randomized controlled trials or case control studies with longer follow-up to investigate the effects of different grafting materials and surgical sites other than mandibular anterior region.

Segmental Corticotomy-Assisted Orthodontic Treatment With Platelet-Rich Fibrin Augmentation of Class III Anomaly

This clinical report presents the outcomes of segmental corticotomy-assisted orthodontic treatment in a class III patient. A 13.5-year-old female patient presented with class III anomaly and a thin alveolus in the mandibular anterior region. After the alignment of the mandibular incisors, segmental corticotomy with platelet-rich fibrin (PRF) was performed in the mandibular incisor area to facilitate incisor retraction to ensure periodontal support after the changes in the inclination of the teeth. Lateral cephalograms were taken at the beginning (T0), precorticotomy (T1), at the end of the treatment (T2), and 2 years after the treatment (T3). Cone-beam computed tomography (CBCT) records were collected at the T1, T2, and T3 periods to evaluate the bone structures. The measurements included the inclination and the position of the mandibular incisors, symphysis width, symphysis height, B-B' width, cervical alveolar width, the vertical alveolar bone level on the labial and the lingual sides, and the amount of labial and lingual bone at the apex in the mandibular central incisor and canine areas.The class I molar and canine relationship was achieved in this borderline case. The amount of labial bone at the root apex and the B-B' width increased. A vertical alveolar bone gain was observed. The facial profile was improved significantly. The treatment outcome was stable at the 2-year follow-up. The segmental anterior mandibular corticotomy provided an effective correcting inclination of the mandibular teeth with the use of class III elastics. This technique ensured the maintenance of a sufficient amount of labial bone with no periodontal side effects.

Maxillary central incisor gingival papilla and zenith heights with and without periodontally accelerated osteogenic orthodontics

Objectives:

The objective of the study is to compare maxillary central incisor gingival papilla and zenith heights photogrammetically in orthodontically treatment patients with and without periodontally accelerated osteogenic orthodontics (PAOOs).

Materials and Methods:

Samples of 29 participants were matched for pre-treatment age and five gingival height dimensions supporting the four maxillary incisors. PAOO active orthodontic treatment time (9.29 vs. 20.47 months) and control post-treatment observation time (10.7 vs. 20.1 months) were significantly shorter (P < 0.05). Linear gingival heights were measured photogrametrically on standardized intraoral frontal photographs perpendicular to a horizontal line constructed parallel to the maxillary central incisal edges.

Results:

(1) The three papillae and two zenith gingival margins moved incisally as a consequence of conventional orthodontic therapy (P < 0.05) but not in PAOO therapy. (2) At least 6-month post-orthodontic treatment, PAOO gingival dimensions were longer for both central incisor zenith heights, and the interdental papilla height between maxillary central incisors was shorter.

Conclusions:

Based on the conditions of the study, orthodontic treatment with and without PAOO results in similar maxillary incisor papilla and zenith heights if viewed from a clinical perspective.

[Relationship of orthodontic treatment and periodontal hard tissue health]

Periodontal tissue, especially the alveolar bone, are closely associated with the progress and efficacy of orthodontic treatment. Prior to and during orthodontic treatment, dentists should fully evaluate the status of periodontal hard tissues to prevent clinical problems. This article aims to discuss bone issues associated with orthodontic treatment, including gingival papilla absence, alveolar bone insufficiency, excessive cortical resistance, and altered passive eruption, etc. The mechanism and prevention methods of these problems are also described.

Three-dimensional imaging control of osteogenesis induced by minimally invasive corticotomies: Perspectives from a case report

Corticotomies are now an integral part of the orthodontist's therapeutic arsenal in adult orthodontics. In recent years, the number of publications about different surgical techniques has increased significantly. This shows that practitioners and patients have a common interest. It is now accepted that corticotomies cause a regional acceleratory phenomenon, which enables a faster dental movement, a reduction in treatment time, as well as a reduction in the risk of root resorption. The perspective of osteogenesis induced by corticotomies has already been mentioned in literature. It could provide a real advantage in maintaining the periodontium, reducing the risk of fenestration or dehiscence and the stability of long-term treatment by increasing the dental bone envelope. Through a clinical case, treated by mini- invasive surgical technique (as described in the previous article), we highlight the potential for osteogenesis induced by alveolar corticotomies and the utility of this procedure in adults.

The effects of NELL on corticotomy-assisted tooth movement and osteogenesis in a rat model

INTRODUCTION

Exogenous Nel-like molecule type 1 (NELL1) represents a potentially attractive clinical treatment option in the orthodontic and other settings because of its osteoinductive and vasculogenic properties.

AIMS

To explore effects of NELL1on corticotomy-assisted tooth movement and osteogenesis in a rat model.

METHODS

Thirty Sprague-Dawley rats were divided into 6 groups: Control, Sham, Tooth movement only, Vehicle, NELL1-LD (low-dose NELL), NELL1-HD (high-dose NELL). Human recombinant NELL1 protein was applied locally (Groups NELL1-LD and NELL1-HD) into buccal mucosa region of left first upper molar. Then the distance and velocity of tooth movement was measured, animals at 6 weeks after surgery were sacrificed, and was followed by computed tomography and histochemical staining.

RESULTS

Both NELL1 groups had higher bone mineral density, greater tooth movement distance and velocity in comparison to the Vehicle group. Proximally and distally, periodontal ligament width was significantly increased in the NELL1-LD and NELL1-HD groups. Decortication enhances remodeling, however, rapid bone formation by high-dose NELL1 may affect bone absorption.

CONCLUSION

Appropriate dose of NELL1 can be administrated to reduce the total time for tooth movement, and may shorten the treatment time in select populations.

A new modified bone grafting technique for periodontally accelerated osteogenic orthodontics

The aim of this study was to introduce an improved surgical technique using a pouch design and tension-free wound closure for periodontally accelerated osteogenic orthodontics (PAOO) in the anterior alveolar region of the mandible.Patients with bone dehiscence and fenestrations on the buccal surfaces of the anterior mandible region underwent the modified PAOO technique (using a pouch design and tension-free closure). Postoperative symptoms were evaluated at 1 and 2 weeks intervals following the procedure. Probing depth (PD), gingival recession depth (GRD), and clinical attachment level (CAL) were assessed at the gingival recession sites at baseline, postoperative 6 and 12 months. Cone-beam computerized tomography (CBCT) was used for quantitative radiographic analyses at baseline, 1 week and 12 months after bone-augmentation procedure.The sample was composed of a total of 12 patients (2 males and 10 females; mean age, 21.9 years) with 72 teeth showing dehiscence/fenestrations and 17 sites presenting with gingival recessions. Clinical evaluations revealed a statistically significant reduction in swelling, pain, and clinical appearance from postoperative week 1 to week 2 (P < .05). Moreover, gingival recession sites exhibited a significant reduction in the GRD and an increase in CAL after surgery with mean root coverage of 69.8% at the end of observation period (P < .01). Both alveolar bone height and width increased after surgery (P < .01) and decreased during the 12-month follow-up (P < .01). However, compared with the baseline records, there was still a significant increase in alveolar bone volume (P < .01).This modified PAOO technique may have advantages in terms of soft and hard tissue augmentation, facilitating extensive bone augmentation and allowing the simultaneous correction of vertical and horizontal defects in the labial aspect of the mandibular anterior area.

[Treatment of a patient with considerably thin alveolar bone and severe open bite]

This case report describes the treatment of a 25-year-old woman with a severe open bite. This patient presented a grade Ⅲ open bite, considerably thin alveolar bone, and evident labial buccal and lingual root form. The open bite was corrected by fixed orthodontic treatment and masticatory exercises. However, the increased pressure in the labial muscle caused by lip muscle exercise suppressed the canines, which resulted in the protrusion of the apices of canine roots out of the alveolar bone. Afterward, HX brackets, instead of self-locking, were used and bonded reversely in the occlusal-gingival direction on the upper canines. The lip muscle exercises were decreased. After adjustment, the roots penetrated back into the cancellous bone, the severe open bite was corrected, and a normal overbite and overjet were achieved. ClassⅠcanine and molar relationships were established. The masticatory function and profile were both considerably improved. This case report showed that a severe nonskeletal open bite can be corrected using orthodontic treatments combined with masticatory exercises.

Recovery of multiple impacted maxillary teeth in a hyperdivergent Class I patient using Temporary Skeletal Anchorage Devices and augmented corticotomy

Treatment of multiple impacted teeth is challenging. Three-dimensional treatment planning can help in delivering a better outcome. This case report presents a patient with an incomplete dental transposition between the canine and lateral incisor of the maxillary right side associated with the impaction of a dilacerated right central incisor. Using a two-stage surgical exposure and augmented corticotomy, the patient's occlusion and smile esthetics were significantly improved, and Class I occlusal relationships with optimal overjet and overbite were achieved after 50 months of orthodontic treatment. Thirty-month posttreatment records revealed a stable result.

Wide Linear Corticotomy and Anterior Segmental Osteotomy Under Local Anesthesia Combined Corticision for Correcting Severe Anterior Protrusion With Insufficient Alveolar Housing

BACKGROUNDS

This article presents an alternate surgical treatment method to correct a severe anterior protrusion in an adult patient with an extremely thin alveolus. To accomplish an effective and efficient anterior segmental retraction without periodontal complications, the authors performed, under local anesthesia, a wide linear corticotomy and corticision in the maxilla and an anterior segmental osteotomy in mandible.

METHODS

In the maxilla, a wide linear corticotomy was performed under local anesthesia. In the maxillary first premolar area, a wide section of cortical bone was removed. Retraction forces were applied buccolingually with the aid of temporary skeletal anchorage devices. Corticision was later performed to close residual extraction space. In the mandible, an anterior segmental osteotomy was performed and the first premolars were extracted under local anesthesia.

RESULTS

In the maxilla, a wide linear corticotomy facilitated a bony block movement with temporary skeletal anchorage devices, without complications. The remaining extraction space after the bony block movement was closed effectively, accelerated by corticision. In the mandible, anterior segmental retraction was facilitated by an anterior segmental osteotomy performed under local anesthesia. Corticision was later employed to accelerate individual tooth movements.

CONCLUSIONS

A wide linear corticotomy and an anterior segmental osteotomy combined with corticision can be an effective and efficient alternative to conventional orthodontic treatment in the bialveolar protrusion patient with an extremely thin alveolar housing.

Morphologic evaluation of dentoalveolar structures of mandibular anterior teeth during augmented corticotomy-assisted decompensation

INTRODUCTION

Our aim in this study was to evaluate the effect of augmented corticotomy on the decompensation pattern of mandibular anterior teeth, alveolar bone, and surrounding periodontal tissues during presurgical orthodontic treatment.

METHODS

Thirty skeletal Class III adult patients were divided into 2 groups according to the application of augmented corticotomy labial to the anterior mandibular roots: experimental group (with augmented corticotomy, n = 15) and control group (without augmented corticotomy, n = 15). Lateral cephalograms and cone-beam computed tomography images were taken before orthodontic treatment and before surgery. The measurements included the inclination and position of the mandibular incisors, labial alveolar bone area, vertical alveolar bone height, root length, and alveolar bone thickness at 3 levels surrounding the mandibular central incisors, lateral incisors, and canines.

RESULTS

The mandibular incisors were significantly proclined in both groups (P <0.001); however, the labial movement of the incisor tip was greater in the experimental group (P <0.05). Significant vertical alveolar bone loss was observed only in the control group (P <0.001). The middle and lower alveolar thicknesses and labial alveolar bone area increased in the experimental group. In the control group, the upper and middle alveolar thicknesses and labial alveolar bone area decreased significantly. There were no significant differences in dentoalveolar changes between the 3 kinds of anterior teeth in each group, except for root length in the experimental group (P <0.05).

CONCLUSIONS

Augmented corticotomy provided a favorable decompensation pattern of the mandibular incisors, preserving the periodontal structures surrounding the mandibular anterior teeth for skeletal Class III patients.

[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.

[Orthognathic surgery: the incisor decompensation and its effect on articulation]

INTRODUCTION

The surgical protocols are based on arches preparation before or immediately after the surgical phase. Incisor guides normalization is achieved by incisor decompensation in three dimensions. Place and extend of surgical movements depend on the incisor position obtained at the end of orthodontic preparation. Extraction versus non extraction depends on incisor position planning. Orthognathic surgery induces muscular and temporo-mandibular joint stress which can cause temporo mandibular dysfunction (TMD).

OBJECTIVES

This article studies relations between incisor decompensation amplitude, orthognathic surgical procedures and risk to create or to increase TMD.

CONCLUSIONS

Sagittal, vertical and transversal incisor decompensation impact to place and amplitude of surgical movements. Incisor decompensation does not seem to induce TMD during orthodontic preparation even if occlusal guide controls are lost. Temporo mandibular dysfunction degrees define surgical movements area, moderate specially mandibular surgical movements and incisor decompensation objectives.

Class III orthognathic surgical cases facilitated by accelerated osteogenic orthodontics: a preliminary report

Objectives

To describe a multidisciplinary treatment approach that includes corticotomy, orthodontic force and orthognathic surgery for the management of skeletal Class III surgical cases. The main advantage of the combined techniques is a reduction in treatment time for young adult patients.

Method

Accelerated Osteogenic Orthodontics (AOO) was delivered to three young adult patients during their pre-surgical orthodontic treatment. After aligning and levelling the dental arches, a piezosurgicalcorticotomy was performed to the buccal aspect of the alveolar bone. Bone graft materials were used to cover the decorticated area and soft tissue flaps were replaced.

Results

The mean time for extraction space closure was 5.4 ± 1.3 months and the mean time for pre-surgical orthodontic treatment was 12.0 ± 0.9 months. The average total treatment time was 20.4 ± 2.4 months. A pre-existing bony fenestration in the buccal cortex adjacent to the right lateral incisor root apex of Case 1 was corrected.

Conclusion

The facial aesthetics of three patients improved following multidisciplinary treatment. This approach may be an efficient method for the orthognathic patient who desires a reduced treatment time, but further clinical research is required.

A pilot clinical study of Class III surgical patients facilitated by improved accelerated osteogenic orthodontic treatments

Objective: 

To evaluate if the improved accelerated osteogenic orthodontics (IAOO) procedure could speed Class III surgical patients' preoperative orthodontic treatment duration and, if yes, to what extent. This study was also designed to determine whether or not an IAOO procedure affects the tooth-moving pattern during extraction space closure.

Materials and Methods: 

The samples in this study consisted of 24 Class III surgical patients. Twelve skeletal Class III surgery patients served as an experimental group (group 1) and the others as a control group (group 2). Before treatment, the maxillary first premolars were removed. For group 1, after the maxillary dental arch was aligned and leveled (T2), IAOO procedures were performed in the maxillary alveolar bone. Except for this IAOO procedure in group 1, all 24 patients experienced similar combined orthodontic and orthognathic treatment. Study casts of the maxillary dentitions were made before orthodontic treatment (T1) and after extraction space closure (T3). All of the casts were laser scanned, and the amount of movement of the maxillary central incisor, canine, and first molar, as well as arch widths, were digitally measured and analyzed by using the three-dimensional model superimposition method.

Results: 

The time durations T3–T2 were significantly reduced in group 1 by 8.65 ± 2.67 months and for T3–T1 were reduced by 6.39 ± 2.00 months (P &lt; .001). Meanwhile, the tooth movement rates were all higher in group 1 (P &lt; .05). There were no significant differences in the amount of teeth movement in the sagittal, vertical, and transverse dimensions between the two groups (P &gt; .05).

Conclusion: 

The IAOO can reduce the surgical orthodontic treatment time for the skeletal Class III surgical patient by more than half a year on average. The IAOO procedures do not save anchorage.

[Bone formation and corticotomy-induced accelerated bone remodeling: can alveolar corticotomy induce bone formation?]

Current orthodontic treatments must answer an increasing demand for faster yet as efficient treatments, especially in adult patients. These past years, the amelioration of orthodontic, anesthetic and orthognathic surgery techniques have allowed considerable improvement of orthodontico-surgical treatments and of adult orthodontic treatments. Alveolar corticotomy (an example of such techniques) accelerates orthodontic tooth movements by local modifications of bone metabolism, inducing a transient osteopenia. This osteopenia allows greater tooth movements than conventional techniques. Whereas there is a growing understanding of the underlying biological mechanisms of alveolar corticotomies, there is little data regarding the osteogenic potential of such technique. In the present article, we review the literature pertaining to alveolar corticotomies and their underlying biological mechanisms and present a clinical case underlining the osteogenic potential of the technique.

Periodontal responses to augmented corticotomy with collagen membrane application during orthodontic buccal tipping in dogs

This prospective randomized split-mouth study was performed to examine the effects of absorbable collagen membrane (ACM) application in augmented corticotomy using deproteinized bovine bone mineral (DBBM), during orthodontic buccal tipping movement in the dog. After buccal circumscribing corticotomy and DBBM grafting into the decorticated area, flaps were repositioned and sutured on control sides. ACM was overlaid and secured with membrane tacks, on test sides only, and the flaps were repositioned and sutured. Closed coil springs were used to apply 200 g orthodontic force in the buccolingual direction on the second and third premolars, immediately after primary flap closure. The buccal tipping angles were 31.19 ± 14.60° and 28.12 ± 11.48° on the control and test sides, respectively. A mean of 79.5 ± 16.0% of the buccal bone wall was replaced by new bone on the control side, and on the test side 78.9 ± 19.5% was replaced. ACM application promoted an even bone surface. In conclusion, ACM application in augmented corticotomy using DBBM might stimulate periodontal tissue reestablishment, which is useful for rapid orthodontic treatment or guided bone regeneration. In particular, ACM could control the formation of mesenchymal matrix, facilitating an even bone surface.

Tooth movement out of the bony wall using augmented corticotomy with nonautogenous graft materials for bone regeneration

This prospective randomized split-mouth study was performed to compare the effects of augmented corticotomy with those of different nonautogenous bone graft materials combined with orthodontic tooth movement in dogs. Decortication was performed on the buccal bone surface of 6 male beagle dogs that were randomly assigned to receive grafts of deproteinized bovine bone mineral, irradiated cortical bone, or synthetic bone. Immediate orthodontic force was applied to the second and third premolars for buccal tipping for 6 weeks. The pocket depth and width of keratinized tissue (WKT) were measured. Histologic and histomorphometric analyses were performed. The probing depth, WKT, and ratio of the area of new bone to that of total bone on the buccal side were not significantly different between groups. All groups had considerable new bone formation on the pressure side. New bone formation on the buccal side and buccal plate formation in the coronal direction along the root surfaces were induced by the bone-derived and PDL-derived mesenchymal matrix, respectively. The angular change between groups was significantly different (P < 0.001). Augmented corticotomy using nonautogenous graft materials facilitated tooth movement without fenestrations and accelerated new bone formation on the pressure side.

[Orthognathic surgery: specific aspects of surgical-orthodontic preparations]

Orthodontic preparation, mandatory before surgery, has benefited from great innovations in periodontics and implantology. The objectives of current orthodontics are short procedures and compliance with dental capital. Using bone anchorage changes treatment modalities for dental compensation. Piezo-electric surgery has become the first line procedure for osteotomies by improving surgical precision and downgrading nerve complications. Alveolar corticotomy has allowed decreasing orthodontic preparation time by causing an acceleration of tooth displacement. Primary transverse and sagittal surgery allow improving or protecting periodontal and muscular systems during orthodontic preparation. Normalization of oro-facial functions is an essential factor of surgical stability. The initial dysfunction justifies an appropriate and rapid management.

Periodontal management in orthognathic surgery: early screening of periodontal risk and its current management for the optimization of orthodontic and surgical treatments

Orthodontic preparation for orthognathic surgery requires correcting mal-occlusions and coordination of arcades. In addition to improving the aesthetics, these treatments can ensure the achievement and sustainability of prosthetics and/or implants. Nevertheless, periodontal structures are easily damaged. Orthodontic displacement can only be applied in the absence of inflammation or weakened periodontal structure. An early detection of periodontal risk should be achievable by prescribers of a surgical-orthodontic treatment. Simplified periodontal examination, with easily detectable warning signs, will help to identify the periodontal risk. Although periodontal treatment follows current "non invasive" trend, some procedures remain necessary to prevent and/or remedy periodontal defects or diseases, such as mineral periodontal reinforcement corticotomy. It is essential that the patient meets all the practitioners to plan and assess the extent of the constraints necessary to optimize results, before starting orthodontic treatment combined with orthognathic surgery. Any periodontal complication (even minor) will be considered as a failure, regardless of good aesthetic and functional results.

How much incisor decompensation is achieved prior to orthognathic surgery?

OBJECTIVES

To quantify incisor decompensation in preparation for orthognathic surgery.

STUDY DESIGN

Pre-treatment and pre-surgery lateral cephalograms for 86 patients who had combined orthodontic and orthognathic treatment were digitised using OPAL 2.1 [http://www.opalimage.co.uk]. To assess intra-observer reproducibility, 25 images were re-digitised one month later. Random and systematic error were assessed using the Dahlberg formula and a two-sample t-test, respectively. Differences in the proportions of cases where the maxillary (1100 +/- 60) or mandibular (900 +/- 60) incisors were fully decomensated were assessed using a Chi-square test (p<0.05). Mann-Whitney U tests were used to identify if there were any differences in the amount of net decompensation for maxillary and mandibular incisors between the Class II combined and Class III groups (p<0.05).

RESULTS

Random and systematic error were less than 0.5 degrees and p<0.05, respectively. A greater proportion of cases had decompensated mandibular incisors (80%) than maxillary incisors (62%) and this difference was statistically significant (p=0.029). The amount of maxillary incisor decompensation in the Class II and Class III groups did not statistically differ (p=0.45) whereas the mandibular incisors in the Class III group underwent statistically significantly greater decompensation (p=0.02).

CONCLUSIONS

Mandibular incisors were decompensated for a greater proportion of cases than maxillary incisors in preparation for orthognathic surgery. There was no difference in the amount of maxillary incisor decompensation between Class II and Class III cases. There was a greater net decompensation for mandibular incisors in Class III cases when compared to Class II cases. Key words:Decompensation, orthognathic, pre-surgical orthodontics, surgical-orthodontic.

Surgically facilitated orthodontic treatment: a systematic review

INTRODUCTION

Corticotomy and dental distraction have been proposed as effective and safe methods to shorten orthodontic treatment duration in adolescent and adult patients. A systematic review was performed to evaluate the evidence supporting these claims.

METHODS

PubMed, Embase, and Cochrane databases were searched until April 2013 for randomized controlled trials, controlled clinical trials, and case series with 5 or more subjects that focused on velocity of tooth movement, reduction of treatment duration, or complications with various surgical protocols. There were no language restrictions during the search phase. Publications were systematically assessed for eligibility, and 2 observers graded the methodologic quality of the included studies with a predefined scoring system.

RESULTS

Eighteen articles met the inclusion criteria. Seven studies were clinical trials, with small investigated groups. Only studies of moderate and low values of evidence were found. Surgically facilitated treatment was indicated for various clinical problems. All publications reported temporarily accelerated tooth movement after surgery. No deleterious effects on the periodontium, no vitality loss, and no severe root resorption were found in any studies. However, the level of evidence to support these findings is limited owing to shortcomings in research methodologies and small treated groups. No research concerning long-term stability could be included.

CONCLUSIONS

Evidence based on the currently available studies of low-to-moderate quality showed that surgically facilitated orthodontics seems to be safe for the oral tissues and is characterized by a temporary phase of accelerated tooth movement. This can effectively shorten the duration of orthodontic treatment. However, to date, no prospective studies have compared overall treatment time and treatment outcome with those of a control group. Well-conducted, prospective research is still needed to draw valid conclusions.

Anterior maxillary intrusion and retraction with corticotomy-facilitated orthodontic treatment and burstone three piece intrusive arch

An adult patient with proclination and spacing was performed orthodontic treatment combined with corticotomy and the burstone three piece intrusive arch who desired a shortened treatment period. The patient had Angle's Class I malocclusion with flaring of the maxillary and mandibular incisors. Pre adjusted edgewise appliance (MBT prescription) was fixed to the maxillary and mandibular teeth. Then corticotomy was performed on the cortical bone of the buccal sides in the maxillary anterior regions. Intrusion and retraction initiated immediately after the corticotomy. The intrusive arch was adjusted once in every 2 weeks. The total treatment time for intrusion was 5 months. Cephalometric superimpositions showed no anchorage loss, and panoramic radiographs showed neither significant reduction in the crestal bone height nor marked apical root resorption. A corticotomy-facilitated orthodontic treatment shortened treatment period without any anchorage loss or adverse effects.

Augmented corticotomy combined with accelerated orthodontic forces in class III orthognathic patients: morphologic aspects of the mandibular anterior ridge with cone-beam computed tomography

PURPOSE

This study used cone-beam computed tomography to evaluate morphologic changes of the mandibular anterior ridge after using augmented corticotomy plus accelerated orthodontia to decompensate mandibular incisors in patients with surgical skeletal Class III.

MATERIALS AND METHODS

Fourteen patients (8 men, 6 women; mean age, 26.14 yr) with skeletal Class III were treated before orthognathic surgery with a technique that combined corticotomy, bone grafting, and accelerated orthodontic forces to decompensate the lower incisors. Three-dimensional cone-beam computed tomograms were taken before treatment (T0) and at the completion of presurgical orthodontic treatment (T1). Measurements of the amount of vertical alveolar bone changes and horizontal bone thickness at the midroot and root apex levels of the mandibular incisors were evaluated.

RESULTS

All patients showed significant proclination of the mandibular incisors at T1. The mean alveolar bone thickness from T0 to T1 increased buccally at the midroot and apex levels, showing statistically significant horizontal bone augmentation at the labial side of the lower anterior mandibular teeth (P < .05). The mean amount of vertical bone change did not show any significant vertical loss of alveolar bone.

CONCLUSION

This new combined technique provided adequate decompensation of the mandibular incisors by increasing horizontal bone thickness in the labial aspect of the mandibular anterior area, without any vertical bone loss. This approach decreases the risk of the typical periodontal complications associated with traditional orthodontics, such as marginal bone loss and gingival recession.