Sutural Distraction Osteogenesis (SDO) Versus Osteotomy Distraction Osteogenesis (ODO) for Midfacial Advancement: A New Technique and Primary Clinical Report

Dentofacial and skeletal effects of two orthodontic maxillary protraction protocols: bone anchors versus facemask

BACKGROUND

Maxillary retrognathia and/or mandibular prognathia are resulting in class III malocclusion. Regarding orthodontic class III malocclusion treatment, the literature reports several treatment approaches. This comparative clinical study investigated two maxillary protraction protocols including bone anchors and Delaire type facemask.

METHODS

Cephalometric radiographs of n = 31 patients were used for data acquisition. The patients were divided into two groups according to their treatment protocol: bone anchored protraction (n = 12, 8 female, 4 male; mean age 11.00 ± 1.76 years; average application: 13.50 ± 5.87 months) and facemask protraction (n = 19, 11 female, 8 male; mean age 6.74 ± 1.15 years; average application: 9.95 ± 4.17 months). The evaluation included established procedures for measurements of the maxilla, mandibula, incisor inclination and soft tissue. Statistics included Shapiro-Wilk- and T-Tests for the radiographs. The level of significance was set at p < 0.05.

RESULTS

The cephalometric analysis showed differences among the two groups. SNA angle showed significant improvements during protraction with bone anchors (2.30 ± 1.18°) with increase in the Wits appraisal of 2.01 ± 2.65 mm. SNA angle improved also during protraction with facemask (1.22 ± 2.28°) with increase in the Wits appraisal of 1.85 ± 4.09 mm. Proclination of maxillary incisors was larger in patients with facemask (3.35 ± 6.18°) and ML-SN angle increased more (1.05 ± 1.51°) than in patients with bone anchors. Loosening rate of bone anchors was 14.58%.

CONCLUSIONS

Both treatment protocols led to correction of a class III malocclusion. However, this study was obtained immediately after protraction treatment and longitudinal observations after growth spurt will be needed to verify the treatment effects over a longer period. The use of skeletal anchorage for maxillary protraction reduces unwanted side effects and increases skeletal effects needed for class III correction.

Maxillary Hypoplasia and Non-Invasive Ventilation: Literature Review and Proposed New Treatment Protocol

The impact of non-invasive ventilation (NIV) on pediatric maxillary growth is a subject of ongoing research considering its increased use in the pediatric population due to technological advancements and broader indications. This review examines the existing literature, encompassing original articles, case reports, and reviews, to evaluate the effects of NIV on maxillary development and explore potential treatment options. Although the majority of studies agree on the adverse effects of prolonged NIV on maxillary development, techniques for its correction remain understudied. Introducing a novel treatment protocol, we addressed the challenge of correcting severe midfacial hypoplasia in a child with congenital central hypoventilation syndrome (CCHS) undergoing NIV therapy, thus sidestepping the necessity for osteotomies. This proposed protocol holds promise in correcting the adverse impact of NIV on maxillary growth, emphasizing the need for further exploration into innovative treatment modalities.

Effect of Bone-Borne Trans -Sutural Distraction Osteogenesis Therapy on the Cranial Base of Children With Midfacial Hypoplasia Due to Cleft Lip and Palate

Bone-borne trans -sutural distraction osteogenesis (TSDO) is widely used to treat midfacial hypoplasia in children with cleft lip and palate; however, its effects on the cranial base are still poorly understood. The authors aimed to study morphological changes in the cranial base after TSDO. Pre and postoperative computed tomography (CT) images of cleft lip and palate children with midfacial skeleton dysplasia who underwent TSDO were collected retrospectively, and their corresponding 3-dimensional models were measured. Results showed no significant change in the length of the anterior or posterior cranial fossa, but the length of the middle cranial fossa increased significantly. The anterior cranial base rotated upward with the sella turcica at the center, whereas the cranial base angle increased. The sphenoid bone exhibited morphological changes. Post-TSDO, the lateral plate of the pterygoid process increased in length. The angle of the 2 lateral plates of the pterygoid process, the greater wings of the sphenoid bone, and the smaller wings of the sphenoid bone decreased. Posterior inclination of the pterygoid process increased. Mean volume of the sphenoidal sinus increased postoperatively compared with the preoperative volume. Apparent changes in the cranial base after TSDO are primarily in the middle cranial fossa, manifesting as an increase in the sphenoid bone body length, expansion of the sphenoidal sinus volume, growth of the pterygoid process forward and downward, a decrease in the angle of both the greater and smaller wings of the sphenoid bone, and an increase in the posterior inclination of the pterygoid process.

Rationale and design for efficacy and safety evaluation of Bone-Anchored Maxillary Protraction (BAMP) for patients with unilateral cleft lip and palate with skeletal anterior crossbite: a single-arm, open-label, non-randomised prospective study protocol

INTRODUCTION

Bone-anchored maxillary protraction (BAMP) was devised recently as a method of direct maxillary protraction using anchor plates implanted in the maxilla and mandible without involving the teeth. Although several reports have described orthognathic effects of BAMP on patients with cleft lip and palate (CLP) with skeletal crossbite, none has described a study of Japanese patients with CLP or of BAMP treatment effects on speech in patients with CLP. This study, by performing BAMP treatment, and by evaluating speech function and skeletal and soft tissues, is intended to clarify BAMP efficacy and safety for patients with unilateral CLP (UCLP) who have skeletal crossbite.

METHODS AND ANALYSIS

This single-arm, open-label, non-randomised prospective study examines 20 patients with UCLP with skeletal crossbite (Wits appraisal ≤-5.0 mm). These 10-15 year-old participants had already undergone cheiloplasty, palatoplasty and bone grafting. The anchor plates are implanted in the zygomatic process in the maxilla and in the anterior part of the mandible. Two weeks after anchor plate implantation, maxillary protraction is started using elastics. Protraction is performed at 150 g per side at the start of protraction, 200 g per side from 1 month after the start of protraction and 250 g per side from 3 months after the start of protraction. The treatment period will be approximately 1½ years. Pretreatment and post-treatment, cephalometric analysis, speech evaluation, nasopharyngeal closure function evaluation and facial soft tissue evaluation will be performed to ascertain the effects of BAMP on patients with UCLP.

ETHICS AND DISSEMINATION

Ethical approval for this study has been received from Tohoku Certificated Review Board of Tohoku University, Japan, CRB2200003. The approval number is 2021-34-2. The results of this research shall be presented at domestic and international academic conferences, and be published to peer-reviewed journals.

TRIAL REGISTRATION NUMBER

jRCTs022210007.

Skeletal, Dental, and Soft Tissue Changes after Applying Active Skeletonized Sutural Distractor (ASSD) for Class III Malocclusion Patients

Background: Nonsurgical treatment of Class III malocclusion may reduce the chances for orthognathic surgery in the future. This study aimed to determine the post-treatment skeletal, dental and soft tissue changes in the anteroposterior plane applying active skeletonized sutural distractor (ASSD) in late adolescent Class III malocclusion patients. Materials and Methods: After screening 13,500 students from 18 secondary schools, a sample of 26 subjects was recruited for this study, with a mean age of 15(±1.4) years after considering the inclusion and exclusion criteria. ASSD appliances were inserted into patients, and lateral cephalometric x-rays were taken for pre- and post-treatment analysis. Dental casts of the patients were also taken and scanned using a 3D laser scanner for comparisons. Results: The intraclass correlation coefficients (ICC) for inter-examiner were 0.87 to 0.99 and 0.96 to 0.99 for lateral cephalometric and dental cast measurements, respectively. The difference in pre- and post-treatment of cephalometric measurements of the mandible showed statistically significant changes for mandibular plane angle (p < 0.001) and SNB angle (p = 0.029). The dental cast measurements showed statistically significant changes of inter-molars width (p < 0.001) as well as palatal (p = 0.002). Conclusions: The results showed statistically significant improvement in skeletal, dental, and soft tissue changes after treatment applying ASSD for Class III malocclusion patients.

Evaluation of the Effects of the Dental and Skeletal Anchored Face Mask Therapies on the Craniofacial System by Using Nonlinear Finite Element Analysis

Aims

The aim of this study was to evaluate the biomechanical effects on the craniofacial complex of skeletal anchorage and dental anchorage during face mask therapy.

Subjects and Methods

Two nonlinear finite element (FE) simulations were performed using a three-dimensional FE model. Face mask therapy with dental anchorage in the upper canines and face mask therapy with skeletal anchorage in the piriform apertures of the maxilla were simulated. In both simulations, the magnitude of the applied force was 750 g per side, and the force direction was 30° forward and downward relative to the occlusal plane.

Results

The circummaxillary sutures showed greater and more uniform stresses in the skeletal anchorage model than the dental anchorage model. This is the result of the more parallel forward movement of the maxilla in the skeletal anchorage model.

Conclusions

In Class III malocclusions with maxillary deficiency, for improved effects on the maxilla, choosing skeletal anchorage may be more effective in face mask therapies

Treatment Options for Class III Malocclusion in Growing Patients with Emphasis on Maxillary Protraction

It is very difficult to diagnose and treat Class III malocclusion. This type of malocclusion involves a number of cranial base and maxillary and mandibular skeletal and dental compensation components. In Class III malocclusion originating from mandibular prognathism, orthodontic treatment in growing patients is not a good choice and in most cases orthognathic surgery is recommended after the end of growth. Approximately 30-40% of Class III patients exhibit some degree of maxillary deficiency; therefore, devices can be used for maxillary protraction for orthodontic treatment in early mixed dentition. In cases in which dental components are primarily responsible for Class III malocclusion, early therapeutic intervention is recommended. An electronic search was conducted using the Medline database (Entrez PubMed), the Cochrane Collaboration Oral Health Group Database of Clinical Trials, Science Direct, and Scopus. In this review article, we described the treatment options for Class III malocclusion in growing patient with an emphasis on maxillary protraction. It seems that the most important factor for treatment of Class III malocclusion in growing patient is case selection.

Rigid External Distractor Aided Conventional Le Fort III Osteotomy Advancement in Adult With Severe Midfacial Hypoplasia

BACKGROUND

Management of severe midfacial hypoplasia is still a challenge for craniofacial team, adult patients with syndromic midfacial hypoplasia made the situation even worse. The authors present the clinical result in an adult patient with Crouzon syndrome treated by rigid external distractor aided conventional Le Fort III procedure.

METHODS

A 26-year-old patient with Crouzon syndrome presented with severe midfacial hypoplasia, a negative overjet of -17 mm, exorbitism, airway obstruction, and masticatory problem, while chief complaint of the patient was abnormal appearance. After Le Fort III osteotomy, rigid external distractor and distraction hooks were fixed. With the aid of rigid external distractor, the midfacial mass was immediately advanced to a desired position, allograft bone grafted in the gaps, and microplate fixed. The device was removed 3 weeks later when the advanced midface was stable.

RESULTS

Point A was advanced by 18.6 mm in horizontal and displaced superiorly 0.5 mm in vertical at the time of device removal. Point A moved backward 1.5 mm and upward 0.3 mm at 2-year follow-up. A good and balanced facial profile was obtained in a short treatment period. Airway obstruction symptoms and exorbitism were relieved.

CONCLUSIONS

The midfacial advancement achieved by rigid external distractor aided conventional Le Fort III osteotomy is a stable, controllable, and timesaving procedure. This technique may become an important choice for adult patients with severe midfacial hypoplasia.

Three-dimensional cephalometric analysis of adolescents with cleft lip and palate using computed tomography-guided imaging

OBJECTIVE

To propose landmarks and a new coordinate system to aid three-dimensional cephalometric analysis of adolescent cleft lip and palate (CLP) using computed tomography (CT) imaging.

METHODS

Sixty-four-row CT images obtained from 52 adolescent patients were retrospectively analyzed with the MIMICS program (MIMICS 10.02; Materialise Technologies, Leuven, Belgium) to determine intrarater reliability of new landmarks for three-dimensional cephalometric analysis before surgery.

RESULTS

Five points were located on each image including the midpoint between both uppermost external points of the external auditory meatus (EAM), the center of the sella turcica (sella, S), the most anterior point on the nasofrontal suture in the midline (nasion, N), and the right and left lowest points of the lower edge of the orbitale (r/l orbitale, r/l Or). The horizontal reference plane was then determined using EAM and bilateral Or. The sagittal reference plane was defined perpendicular to the horizontal plane, passing through N and S. The coronal reference plane included the EAM landmark and was perpendicular to the sagittal and horizontal planes. All 5 points had high intrarater reliability and proved easy to use in constructing the new coordinate system. The horizontal, sagittal, and coronal reference planes formed by these respective points improved the ease of performing three-dimensional cephalometric analysis of CLP adolescents with CT imaging.

CONCLUSIONS

Our 5 landmarks provided reliable CT-guided three-dimensional cephalometric analysis of CLP, allowing for accurate quantitative assessment in adolescents before orthognathic surgery.

A New Way to Accelerate the Distraction of the Transpalatal Suture in Growing Dogs Using Recombinant Human Bone Morphogenetic Protein-2

OBJECTIVE

The purpose of this study was to evaluate the administration of recombinant human bone morphogenetic protein-2 (rhBMP-2) on trans-sutural distraction osteogenesis (TSDO) of the transverse palatal suture in growing dogs.

STUDY DESIGN

A total of 36 growing dogs were used in this study. The experimental animals were treated with different elastic force and rhBMP-2. The bone regeneration was determined with X-ray, histology, and clinical evaluation. The computed values underwent statistical analyses using analysis of variance.

RESULTS

The maxillary complex was most noticeably advanced with an applied elastic force of 600 g (22.4 ± 5.0 mm) and 800 g + rhBMP-2 (24 ± 5.1 mm). Immunohistochemical staining showed that the expression of bone morphogenetic protein-2 and bone morphogenetic protein-4 varied with different elastic force. These changes were statistically significant when 600 g and 800 g + rhBMP-2 were applied within 2 weeks of distraction when compared with controls (P < .05).

CONCLUSIONS

The results of this study suggest that TSDO in the growing dog should be safe and well tolerated when inducing bony lengthening of the maxilla. rhBMP-2 plays an important role in bone regeneration using TSDO.

Trans-Sutural Distraction Osteogenesis for Midfacial Hypoplasia in Growing Patients with Cleft Lip and Palate: Clinical Outcomes and Analysis of Skeletal Changes

BACKGROUND

Although maxillary distraction osteogenesis has been used for early treatment of midfacial hypoplasia, the inevitable osteotomies are still a complicated and invasive procedure for growing patients. Based on the bone-borne trans-sutural distraction osteogenesis, novel improvements to the approach were made to treat midfacial hypoplasia, and the clinical outcomes and skeletal changes were analyzed.

METHODS

Seventy consecutive growing cleft lip and palate patients with midfacial hypoplasia were treated with trans-sutural distraction osteogenesis. The distraction system consists of a rigid external distractor, nickel-titanium shape memory alloy spring, and bone-borne traction hooks. The whole distraction process was recorded in detail clinically. Lateral cephalographs and computed tomographic scans were taken and analyzed by cephalometric measurement and color-map analysis to assess the skeletal changes.

RESULTS

All of the patients except one achieved satisfactory appearance and occlusal relationship. The unilateral maximum traction force presented an increased trend with age, but this relationship was not absolute. The whole trans-sutural distraction osteogenesis process was divided into three clinical stages: the startup period, the rapid movement period, and the consolidation period. Cephalometric analysis showed a great increase in SNA, ANB and horizontal movement of the maxillae after distraction, but with marginal relapse at 6 to 18 months postoperatively. Visualized changes of the midfacial skeleton were observed by three-dimensional color mapping. The results showed an unequal advancement in different regions.

CONCLUSION

Trans-sutural distraction osteogenesis process with adaptations offers an alternative method for the early treatment of midfacial hypoplasia in growing patients with cleft lip and palate.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Transsutural distraction and tissue regeneration of the midfacial skeleton: experimental studies in growing dogs

Objective : The purpose of this study was to evaluate the effect of different mechanical forces on the expansion of the palatine suture using transsutural distraction osteogenesis. Methods : A total of 48 dogs were used in this study. The experimental groups were treated with a custom-designed internal distractor. Bone regeneration was determined with x-rays and histology. The computed values underwent statistical analyses using analysis of variance. Results : The maxillary complex was most noticeably advanced with an applied mechanical force of 600 g (20.15 ± 1.36 mm), compared with forces of 400 g (19.88 ± 1.41 mm) and 800 g (2.24 ± 0.93 mm). Immunohistochemical staining showed that the expression of bone morphogenetic protein-2 and bone morphogenetic protein-4 fluctuated with different mechanical forces. These changes were statistically significant when 600 g of force was applied within 30 days of distraction (P < .05). Conclusions : Transsutural distraction osteogenesis in the growing dog should be safe and well tolerated in inducing bony lengthening of the maxilla, and the optimal force is 600 × g. Bone morphogenetic protein-2 and bone morphogenetic protein-4 may play an important roles in the signaling pathways that link mechanical forces and biological responses.

Trans-sutural distraction osteogenesis for alveolar cleft repair: an experimental canine study

OBJECTIVE

To explore a new method of repair of alveolar cleft by trans-sutural distraction osteogenesis.

DESIGN

Nine 8-week-old mongrel dogs were assigned randomly to two groups with three in the control group and six in the experimental group.

SETTING

First, an alveolar cleft model was created surgically in all animals. After 2 weeks, a U-shaped distractor, made of nickel-titanium (NiTi) shape memory alloy wire with 200 g tensile force, was inserted into the premaxilla of the experimental dogs to distract the mid-premaxillary suture for 3 weeks. Periosteoplasty of the alveolar cleft was performed when the premaxilla at the side of cleft approached the maxilla at the same side. The distractor was removed 2 weeks post periosteoplasty.

OUTCOME MEASURES

The results were evaluated clinically, radiographically, and morphologically.

RESULTS

The cleft model was stable and similar to the human alveolar cleft. No spontaneous bone union occurred in the control. In experimental dogs, the premaxilla was moved slowly toward the maxilla, and the cleft became gradually narrower and closed in the third week. Radiographically, the distracted mid-premaxillary suture showed a gradually widened triangle, with the tip of the triangle pointed posteriorly. The density of the distracted triangle suture was increased gradually. The alveolar cleft was completely bony 3 months post periosteoplasty. The morphology of the mid-premaxillary suture was also restored.

CONCLUSION

The alveolar cleft could be repaired by the technique of mid-premaxillary suture distraction using the elastic device of NiTi shape memory alloy.

Comparative evaluation of maxillary protraction with or without skeletal anchorage

INTRODUCTION

The aim of this prospective clinical study was to evaluate the skeletal, dentoalveolar, and soft-tissue effects of maxillary protraction with miniplates compared with conventional facemask therapy and an untreated Class III control group.

METHODS

Forty-five subjects who were in prepubertal or pubertal skeletal growth periods were included in the study and divided into 3 groups of 15 patients each. All subjects had skeletal and dental Class III malocclusions with maxillary deficiency, vertically normal growth pattern, anterior crossbite, Angle Class III molar relationship, normal or increased overbite, and retrusive nasomaxillary complex. Before maxillary protraction, rapid maxillary expansion with a bonded appliance was performed in both treatment groups. In the first group (MP+FM), consisting of 5 girls and 10 boys (mean age, 10.91 years), facemasks were applied from 2 titanium miniplates surgically placed laterally to the apertura piriformis regions of the maxilla. The second group (FM) of 7 girls and 8 boys (mean age, 10.31 years) received maxillary protraction therapy with conventional facemasks applied from hooks of the rapid maxillary expansion appliance. The third group of 8 girls and 7 boys (mean age, 10.05 years) was the untreated control group. Lateral cephalometric films were obtained at the beginning and end of treatment or observation in all groups and analyzed according to a structural superimposition method. Measurements were evaulated statistically with Wilcoxon and Kruskal-Wallis tests.

RESULTS

Treatment periods were 6.78 and 9.45 months in the MP+FM and FM groups, respectively, and the observation period in the control group was 7.59 months. The differences were significant between the 3 groups (P <0.05) and the MP+FM and FM groups (P <0.001). The maxilla moved forward for 2.3 mm in the MP+FM group and 1.83 mm in the FM group with maxillary protraction. The difference was significant between 2 groups (P <0.001). The protraction rates were 0.45 mm per month in the MP+FM group and 0.24 mm per month in the FM group (P <0.001). The maxilla showed anterior rotation after facemask therapy in the FM group (P <0.01); there was no significant rotation in the MP+FM group. Posterior rotation of the mandible and increased facial height were more evident in the FM group compared with the MP+FM group (P <0.01). Both the maxilla and the mandible moved forward significantly in the control group. Protrusion and mesialization of the maxillary teeth in the FM group were eliminated in the MP+FM group. The maxillomandibular relationships and the soft-tissue profile were improved remarkably in both treatment groups.

CONCLUSIONS

The undesired effects of conventional facemask therapy were reduced or eliminated with miniplate anchorage, and efficient maxillary protraction was achieved in a shorter treatment period.

Advancement of the midface, from conventional Le Fort III osteotomy to Le Fort III distraction: review of the literature

Since its introduction in about 1950, the Le Fort III (LF III) procedure has become a widely accepted treatment for correction of midface hypoplasia and related functional and esthetic problems. As long-term surgical experience grows and improvements are made in technique, equipment and peri-operative care, the number of LF III procedures performed worldwide is increasing. A number of fundamental questions concerning the technique remain unclear, and large, conclusive studies are lacking owing to the relative rarity of severe midface hypoplasia. This literature review aims to address problems, such as the indication field, timing of surgery, rate of relapse and the use of distraction osteogenesis. An overview of the history and technique of LF III osteotomy and distraction is provided, together with a comprehensive review of the available clinical data.