Bone anchored intraoral device for transmandibular distraction

Three-dimensional dento-skeletal effects of mandibular midline distraction and surgically assisted rapid maxillary expansion: A retrospective study

It was the aim of the study to provide a three-dimensional evaluation of dento-skeletal effects following bone-borne vs tooth-borne mandibular midline distraction (MMD) and tooth-borne surgically assisted rapid maxillary expansion (SARME). A retrospective observational study was conducted. Cone beam computed tomography (CBCT) records were taken pre-operatively (T1), immediately post-distraction (T2) and 1 year post-operatively (T3). All included 30 patients had undergone MMD (20 bone-borne MMD; 10 tooth-borne MMD). A total of 20 bone-borne MMD and 8 tooth-borne MMD patients had simultaneously undergone tooth-borne SARME. At T1 vs T3, canine (p = 0.007; 26.0 ± 2.09 vs 29.2 ± 2.02) and first premolar (p = 0.005; 33.8 ± 2.70 vs 37.0 ± 2.43) showed significant expansion on the tip level for tooth-borne MMD. This was no significant on the apex level, indicating tipping. Bone-borne MMD showed a parallel distraction gap, whereas tooth-borne MMD showed a V-shape. There was a significant (p = 0.017; 138 ± 17.8 vs 141 ± 18.2) inter-condylar axes increase for bone-borne MMD. In conclusion, bone-borne vs tooth-borne MMD and tooth-borne SARME showed stable dento-skeletal effects at 1 year post-operatively. Bone-borne and tooth-borne MMD seemed not to be superior to each other. The choice of distractor type therefore depends more on anatomical and comfort factors.

Current Practice for Transverse Mandibular and Maxillary Discrepancies in the Netherlands: A Web-Based Survey Among Orthodontists and Oral and Maxillofacial Surgeons

The main objective of this study was to provide an overview of the current practice for transverse mandibular and maxillary discrepancies in the Netherlands using a web-based survey. Orthodontists (ORTHO) and Oral and Maxillofacial Surgeons (OMFS) in the Netherlands were invited to the web-based survey via their professional association. Three cases were presented which could be treated non-surgically and surgically. Participants were asked what treatment they preferred: no treatment, orthodontic treatment with optional extractions or surgically assisted orthodontic treatment. The web-based survey ended with questions on various technical aspects and any experienced complication. Invitation was sent to all 303 members of professional association for ORTHO and to all 379 members of professional association for OMFS. Overall response number was 276 (response rate of 40.5%), including 127 incomplete responses. Generally, ORTHO prefer orthodontic treatment with optional extractions and OMFS lean towards surgically assisted orthodontic treatment. Mandibular Midline Distraction appears to be less preferred, possibly due to lack of clinical experience or knowledge by both professions despite being proven clinical stable surgical technique with stable long-term outcomes. There seems to be consensus on technical aspects by both professions, however, there are various thoughts on duration of consolidation period. Complications are mostly minor and manageable.

Three-dimensional soft tissue effects of mandibular midline distraction and surgically assisted rapid maxillary expansion: an automatic stereophotogrammetry landmarking analysis

Studies on mandibular midline distraction (MMD) are mostly performed using conventional research methods. Concerning surgically assisted rapid maxillary expansion (SARME), more research is conducted using three-dimensional (3D) techniques. Research on bimaxillary expansion, the combination of MMD and SARME, is reported sparsely. The main objective of this study was to provide a 3D evaluation of soft tissue effects following SARME and/or MMD. Patients who underwent SARME and/or MMD between 2008 and 2013 were included. Stereophotogrammetry was undertaken at the following time points: preoperative (T1), immediately post-distraction (T2), 1year postoperative (T3). An automatic 3D facial landmarking algorithm using two-dimensional Gabor wavelets was applied for the analysis. Twenty patients who had undergone SARME were included, 12 of whom had undergone bimaxillary expansion. Age at the time of surgery ranged from 16 to 47 years. There was a significant downward displacement of soft tissue pogonion. Furthermore, there was a significant mean increase of 2.20mm in inter-alar width and a non-significant mean increase of 1.77mm in inter-alar curvature point width. In conclusion, automatic stereophotogrammetry landmarking analysis of soft tissue effects showed downward displacement of soft tissue pogonion following bimaxillary expansion and transverse widening of the inter-alar width and a tendency towards an increase in inter-alar curvature point width after SARME.

Three-dimensional evaluation of mandibular midline distraction: A systematic review

OBJECTIVE

To provide a literature overview on mandibular midline distraction (MMD) using three-dimensional (3D) imaging analysis techniques. Regarding different distractor types, the focus was on changes in position and/or morphology of the mandibular condyle and temporomandibular joint (TMJ), skeletal effects, dental effects, soft tissue effects, and biomechanical and masticatory effects, specifically on the mandible and TMJ.

METHODS

Studies up to March 27 2017 were included, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement guidelines, using Embase, Medline OvidSP, Web-of-science, Scopus, Cochrane, and Google Scholar.

RESULTS

Thirty-one full-text papers were assessed for eligibility and 15 met the inclusion criteria: prospective (2), retrospective (2), case-report (1) and computational analysis (10). All included studies were graded low (level 4-5) for quality of evidence, using the Oxford Centre for Evidence-Based Medicine criteria.

CONCLUSION

There is a limited number of studies available, with low levels of evidence and small sample sizes. Bone-borne distraction seems preferable when taking skeletal effects into account. Tooth-borne distraction leads to significant dental tipping. Hybrid distractors combined with parasymphyseal step osteotomy seem to be the most stable under functional masticatory loads. The effects of chewing appeared to be marginal during the latency period. No permanent TMJ symptoms were reported, and little is known about soft tissue effects.

SYSTEMATIC REVIEW REGISTRATION

International Prospective Register of Systematic Reviews, PROSPERO CRD42014010010.

Mandibular Widening by Distraction Osteogenesis in the Treatment of a Constricted Mandible and Telescopic Bite

Objective

Documentation of the application of mandibular widening by distraction osteogenesis and orthodontics.

Patients

Three patients with telescopic bite resulting from an extremely constricted mandible related to hypoglossia-hypodactyly syndrome.

Intervention

Mandibular widening by distraction osteogenesis using an extraoral device and subsequent orthodontic treatment.

Results

The extremely constricted mandible and telescopic bite were dramatically improved by mandibular widening using distraction osteogenesis and subsequent orthodontics. Two of the three patients had transient complications; one reported temporomandibular joint pain and the other showed evidence of periodontal damage.

Conclusion

Mandibular widening by distraction osteogenesis is an effective technique for the treatment of telescopic bite resulting from an extremely constricted mandible.

Facial improvement after mandibular midline distraction and surgically assisted rapid maxillary expansion

This case report describes the retreatment of a 49-year-old woman with severe crowding in the mandibular incisor region and tapered maxillary and mandibular arches. Treatment consisted of mandibular midline distraction and surgically assisted rapid maxillary expansion to increase arch length. The need for proper presurgical orthodontics is described, and the complications during treatment are discussed. The results of treatment, including the superimposition of 3-dimensional facial scans, are presented. The treatment approach we used is typically indicated for patients with previous extractions of all first premolars who develop significant crowding after treatment. Surgical planning in 3 dimensions and the use of a 3-dimensional designed surgical osteotomy guiding wafer should improve the predictability of this treatment approach.

Comparison of two preoperative protocols for mandibular symphyseal distraction osteogenesis to reduce the risk of tooth damage

Two techniques to separate the lower incisors prior to mandibular symphyseal distraction osteogenesis (MSDO) were evaluated with respect to avoiding tooth damage.

METHODS

Fifty patients (20.2 ± 7.0 years) requiring MSDO were treated with a tooth-borne appliance by utilizing two preoperative protocols to separate the central incisors: i) brackets and a V-bent wire with an open coil spring (two-step; TS; n = 24) and ii) a wire attached from the appliance to the central incisors with subsequent dento-alveolar expansion prior to surgery (one-step; OS; n = 26). The distance between the lower incisors was measured preoperatively on radiographs and measurements at the cast models were performed. Complications and radiographs were analyzed.

RESULTS

The mean distance (±SD) between the lower central incisors for OS and TS prior to surgery was 3.44 ± 1.05 and 3.18 ± 1.13 mm, respectively. The mean expansion for OS and TS was 4.3 ± 2.9 and 4.3 ± 2.7 mm at the dental level and 3.8 ± 3.2 and 4.0 ± 2.1 mm at the bone level, respectively. Four patients undergoing the TS and one patient undergoing the OS showed transient dental complications.

CONCLUSION

Pre-surgical dento-alveolar expansion by utilizing a one-step technique to separate the lower central incisors reduces the risk of permanent tooth damage and weakens the mandibular bone in the midline.

Biomechanical Effects of Novel Osteotomy Approaches on Mandibular Expansion: A Three-Dimensional Finite Element Analysis

PURPOSE

Surgically assisted mandibular arch expansion has proved to be an effective treatment modality in alleviating constriction and crowding issues. However, only mandibular symphyseal distraction osteogenesis has been in favor for the purpose of mandibular arch expansion. In addition, no relevant study has compared the biomechanical response of different osteotomy designs on mandibular expansion. The present study evaluated the effect of different osteotomy approaches and modes of loading on the expansion of the adult mandible using biomechanics.

MATERIALS AND METHODS

To address the research purpose, 9 finite element (FE) models, including 2 novel osteotomy designs, were simulated. Stress, strain, and displacement of crown, root, and bone were calculated and compared under different osteotomy approaches and loading conditions.

RESULTS

The biomechanical response envisaged by the FE models in terms of displacement on the X axis was consistent from the anterior to posterior teeth with parasymphyseal step osteotomy and a hybrid mode of force application. In addition, the amount of displacement predicted by parasymphyseal step osteotomy with the hybrid mode was greater compared with that of the other models.

CONCLUSIONS

The results of our study suggest parasymphyseal step osteotomy with the hybrid mode is a viable treatment option for true bony expansion in the adult mandible.

Treatment of a unilateral complete lingual crossbite in an adult with skeletal anchorage assisted orthodontics

An asymmetry caused by a complete lingual crossbite can compromise aesthetics and impair occlusal function. The following case report describes the correction of a complete lingual crossbite using orthodontic mini implants and mini-plates to achieve absolute anchorage. A comprehensive correction of the crossbite and re-establishment of the buccal occlusion was achieved.

A systematic review on soft-to-hard tissue ratios in orthognathic surgery part II: Chin procedures

PURPOSE

Precise soft-to-hard tissue ratios in orthofacial chin procedures are not well established. The aim of this study was to determine useful soft-to-hard tissue ratios for planning the magnitude of sliding genioplasty (chin osteotomy), osseous chin recontouring and alloplastic chin augmentation.

MATERIAL AND METHODS

A systematic review of English and non-English articles using PubMed central, ProQuest Dissertations and Theses, Science Citation Index, Elsevier Science Direct Complete, Highwire Press, Springer Standard Collection, SAGE premier 2011, DOAJ Directory of Open Access Journals, Sweetswise, Free E-Journals, Ovid Lippincott Williams & Wilkins total Access Collection, Wiley Online Library Journals, and Cochrane Plus databases from their onset until July 2014. Additional studies were identified by searching the references. Search terms included soft tissue, ratios, genioplasty, mentoplasty, chin, genial AND advancement, augmentation, setback, retrusion, impaction, reduction, vertical deficit, widening, narrowing, and expansion. Study selection criteria were as follows: only academic publications; human patients; no reviews; systematic reviews or meta-analyses; no cadavers; no syndromic patients; no pathology at the chin or mandible region; only articles of level of evidence from I to IV; number of patients must be cited in the articles; hard-to-soft tissue ratios must be cited in the articles or at least are able to be calculated with the quantitative data available in the article; if all patients of one article have had bilateral sagittal split osteotomy (BSSO) performed along with chin osteotomy, there should be an independent group evaluation of the data concerning to the chin; and no restriction regarding the size of the group. Independent extraction of articles by two authors using predefined data fields, including study quality indicators (level of evidence).

RESULTS

The search identified 22 articles. Eleven additional articles were found in their reference sections. Of these, two were evidence level IIIb, three were evidence level IIb, and the rest were evidence level IV. Three studies were prospective in nature. A high variability of soft-to-hard tissue ratios regarding genioplasty seemed to disappear if data were stratified according to confounding factors. With the available data, a soft-to-hard pogonion ratio of 0.9:1 and 0.55:1 could be used for chin advancement and chin setback surgery, respectively.

CONCLUSION

Advancement and extrusion movements of the chin segment show respectively a 0.9:1 of sPg:Pg horizontally and 0.95:1 of sMe:Me vertically. Setback and impaction movements show respectively a -0.52:1 of sPg:Pg horizontally and -0.43:1 of sMe:Me vertically. Prospective studies are needed that stratify by confounding factors such as type of osteotomy technique, magnitude of the movement, age, sex, race/ethnicity, and quantity and quality of the soft tissues. More specifically, studies are needed regarding soft-to-hard tissue changes after chin extrusion ("downgrafting"), intrusion ("impaction"), and widening and narrowing surgery.

Symphyseal distraction in the context of orthodontic treatment: a series of 35 cases

INTRODUCTION

Use of symphyseal distraction osteogenesis to treat a mandibular bone deficit with tooth-jaw discrepancy due to lack of space makes it possible to avoid the risks associated with the techniques usually envisaged (stripping, labioversion of incisors, extractions).

PATIENTS AND METHOD

This retrospective study presents the symphyseal distraction technique used in the maxillofacial surgery department of Lille University Hospital between January 1998 and March 2013. Treatment efficacy, complications and the stability of results were all evaluated.

RESULTS

Thirty-five patients were included in the study. The gain of inter-mental-foramen space was on average 7 mm (3-12, standard deviation 1.8 mm). A good occlusal result with dental Class I and no labioversion of the lower incisors was obtained in 27 of the 35 patients (77%).

CONCLUSION

Mandibular distraction by symphyseal osteotomy seems to be a quick, safe treatment for an anterior transversal mandibular deficit giving results that are stable over time. Its success depends on good collaboration between the orthodontist and the surgeon, and on strict patient selection.

Introduction of the "Rotterdam mandibular distractor" and a biomechanical skull analysis of mandibular midline distraction

The Rotterdam mandibular distractor (RMD) is a slim, rigid, boneborne distractor for use in midline distraction of the mandible. We did a biomechanical study to compare the RMD with the Trans Mandibular Distractor-flex (TMD-flex). This included an anatomical biomechanical study that was conducted on 9 dentate human cadaveric heads using both the RMD and the TMD-flex. In the vertical plane less tipping was measured in the RMD group than in the TMD-flex group. Significantly less skeletal tipping was found in the horizontal plane in the RMD group (P=0.021). There was minimal difference in the intercondylar distance between the groups. As the amount of lateral displacement of the condyle was similar in both groups and there was less rotational movement in the RMD group, the TMD-flex would be expected to increase stress on the temporomandibular joint. As a result of the increased parallel widening in the vertical plane, more basal bone is being created and less relapse is expected using the RMD. The study design involves an in vitro anatomical model and conclusions must be drawn with care. At present clinical studies are under way and results will follow.

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Facing a dental crowding, the orthodontist has several therapeutic options. If maxillary expansion is often used, mandibular orthodontic expansion is proscribed because of its tendency of inefficiency and relapse. Mandibular symphyseal distraction osteogenesis allows to remove this proscription. This therapeutic protocol consists in a pre-surgery orthodontic preparation phase followed by surgery (symphyseal osteotomy and placement of the distraction device), a latency period (five to seven days), then an activation period (most of the time 1 mm/day in two steps) followed by a consolidation period (three months) during which the orthodontic treatment can be resumed. Skeletal and alveolar expansion corrects dental crowding. This surgical technique is versatile, minimally invasive, and stable with time. Major indications are hypoplastic symphysis, anterior crowding, relapse of orthodontic treatments and some syndromes. This method can also be an answer to aesthetic concerns or an alternative for treatment of dental crowding. Face à un encombrement dentaire, l'orthodontiste dispose de plusieurs options thérapeutiques. Si au maxillaire, l'expansion est fréquemment utilisée, l'expansion mandibulaire orthodontique est proscrite, car inefficace et récidivante. La distraction symphysaire permet de lever cet interdit. Ce protocole thérapeutique comprend : une préparation orthodontique pré-chirurgicale, une chirurgie (ostéotomie symphysaire et pose du distracteur), une période de latence (cinq à sept jours), puis une période d'activation (le plus souvent 1 mm/j en deux fois) suivie d'une période de consolidation (trois mois) pendant laquelle le traitement orthodontique peut être repris. L'expansion basale et alvéolaire corrige l'encombrement dentaire. Cette technique est polyvalente, peu invasive et stable dans le temps. Ses indications majeures sont l'hyposymphysie, l'encombrement incisif, la récidive de traitements orthodontiques et certains grands syndromes. Cette méthode peut aussi être proposée pour répondre à des préoccupations esthétiques ou comme alternative aux traitements classiques de l'encombrement dentaire.

Morbidity related to "endo-corticotomies" for transpalatal osteodistraction

INTRODUCTION

The objective of this study was to evaluate morbidity arising from transnasal, endoscopically assisted corticotomies for transpalatal osteodistraction. This minimally invasive technique utilizes three 1-cm incisions in the nasal vestibule instead of the classical, two lateral and one medial oral vestibule incisions of 2-3 cm and 1cm long, respectively.

MATERIAL AND METHODS

Fifty-nine patients (33 females and 26 males; age range: 9-50 years, mean 20 years) who underwent surgery in the hub hospital by the senior surgeon were included in a prospective registry. Patients with congenital maxillary hypoplasia were excluded. Difficulties were systematically recorded.

RESULTS

Mean operative time was 68 min (SD: 15 min) when no other procedures were combined with the transpalatal osteodistraction. Ten difficulties unrelated to either the device or oral hygiene were encountered: rhinorrhoea and minor nasal obstruction (1), nasal bleeding with hospital admission (1), periostitis at the piriform aperture that necessitated revision using local anaesthesia (1), periostitis with spontaneous healing (1), postoperative pain (2), dermatitis (1), infraorbital ecchymosis (1), excessive postoperative oedema (1), and prolonged cheek hyperaesthesia (1).

DISCUSSION AND CONCLUSION

Operative time as well as both percentage and nature of complications was similar to those experienced with "open-sky TPD" (transpalatal distraction), with less pronounced oedema and patient surgical threshold decreased.

Mandibular Symphyseal Distraction Osteogenesis Using a Bone-Supported Distractor

Increases in mandibular width by symphyseal distraction osteogenesis have recently been shown to be an acceptable and stable treatment option for transverse deficiencies. This case report presents the application of symphyseal distraction osteogenesis for increasing mandibular width using a bone-supported distractor as part of the orthodontic treatment of a 14-year-old male with a tapered shaped mandible and severe mandibular anterior crowding.

Nonextraction Treatment with Rapid Maxillary Expansion and Mandibular Symphyseal Distraction Osteogenesis and Vertical Skeletal Dimensions

OBJECTIVE

To investigate the effects of rapid maxillary expansion (RME) and mandibular symphyseal distraction osteogenesis (MSDO) on vertical dimensions of the face.

MATERIALS AND METHODS

Fourteen patients, nine girls and five boys, underwent RME and MSDO procedures. Distraction was carried out at a rate of 1 mm per 24 hours with a tooth-borne appliance. The amount of distraction was 7 mm for each patient. Standardized lateral cephalograms were taken at the following time periods: before treatment (T0), after RME (T1), at the completion of MSDO (T2), and at the end of fixed orthodontic treatment (T3). The data were evaluated by using a general linear model of repeated-measures analysis of variance and paired t-tests at the 95% confidence level.

RESULTS

RME significantly increased the vertical dimensions of the face and decreased the overbite (P < .001). Although the vertical parameters of the face on the lateral cephalogram decreased after MSDO, these decreasing effects were statistically insignificant just for the distances measured from the horizontal reference line to the chin points. In other words, MSDO decreased the vertical skeletal dimensions that were increased by RME, but this neutralizing effect of MSDO was not as much as the increase caused by RME.

CONCLUSION

Treatment modalities (RME, MSDO, and fixed orthodontic treatment) described in this study, in total, had little effect on the vertical skeletal measurements of the face.

Mandibular symphyseal distraction osteogenesis: review of three techniques

Mandibular symphyseal distraction osteogenesis (MSDO) is an alternative strategy to correct mandibular transverse deficiencies and dental crowding. Only a limited number of practitioners have reported their clinical experience and potential complications of this procedure to widen the mandible in a large case series. This study involved retrospective analysis of 40 patients who underwent mandibular symphyseal distraction osteogenesis. Three different types of distractor were used to widen the mandible: tooth-borne in 21 patients, bone-borne in 5 patients and hybrid (both bone and tooth-borne) in 14 patients. The distraction amount ranged from 7 to 11 mm (mean 7.31 mm). While 39 patients underwent successful mandibular symphyseal distraction, there was one failure. Most of the complications were experienced in bone-borne distractors, such as breakage of the distractor rod, gingival recession, secondary infection and ptosis of the chin. In the light of these findings, it is suggested that a lingually placed tooth-borne hyrax appliance is more suitable and reliable than the other distraction devices. Further larger studies are needed in order to better evaluate the effectiveness of bone-borne or hybrid devices.

Effects of mandibular symphyseal distraction osteogenesis on mandibular structures

INTRODUCTION

The purpose of this study was to evaluate the effects of mandibular symphyseal distraction osteogenesis on dental and mandibular skeletal structures with a tooth- and bone-borne distraction device.

METHODS

The sample comprised 20 patients, ranging in age from 15.8 to 23.3 years (mean, 20.1 +/- 2.3 years) at the start of treatment. The distraction device was activated 1 mm per day. The device was usually maintained in position about 90 days after surgery. Records were obtained at the start of treatment, at the end of distraction (11.4 +/- 2.2 days after surgery), and at follow-up periods (24.1 +/- 4.2 months after surgery). The records included posteroanterior cephalograms and study casts. The data were analyzed statistically by using the repeated measure analysis of variance and paired t test.

RESULTS

Posteroanterior cephalometric analysis demonstrated no significant changes in bigonial widths and ramal angles at the end of distraction period. On the other hand, bimolar widths were significantly increased, whereas bicondylar widths were markedly decreased. The dental cast analysis indicated that the maximum amount of increase was found between the mandibular canines, and the widening effect gradually decreased from the mandibular canines to the second molars. The follow-up data confirmed that the treatment results were stable.

CONCLUSIONS

The long-term findings indicate that mandibular symphyseal distraction osteogenesis is an efficient nonextraction treatment alternative for mandibular dental crowding to increase mandibular skeletal and dental arch widths.

Anterior transmandibular osteodistraction: clinical and model observations

INTRODUCTION

The aim of this paper was to study the effect of transmandibular distraction on the periodontal and dental structures, and the initial movements of the mandibular halves, when using an axial plane non-rigid bone-borne distractor (TMD).

MATERIAL AND METHODS

Fourteen patients undergoing bimaxillary transverse osteodistraction had their six lower anterior teeth assessed for mobility, sensitivity, and pocket depth. Recordings were made pre-operatively, post-distraction, post-consolidation and at 1-year follow-up. Selected landmarks on pre-operative and post-consolidation models were also digitised in three dimensions to study individual tooth movements, and positional changes of the mandibular halves.

RESULTS

Pockets depths around the incisor teeth increased during the consolidation period (probably due to reduced oral hygiene), but returned to normal by the 1-year post-operative consultation. Tooth mobility increased temporarily in the active phase (central incisors, lateral incisors) and in the consolidation phase (lateral incisors, canine teeth). Sensitivity to cold was temporarily lost in the incisor teeth, probably as a result of 'apical contusion'. One central incisor was inadvertently apically osteotomized and needed root canal treatment. The angle between the mandibular halves closed by 9.4 degrees.

CONCLUSION

Periodontal and dental morbidity is transient and limited to the distraction and consolidation period, as long as the tooth apices are avoided when the osteotomy is performed. A step-design osteotomy may be preferable when the central incisor apices are close to each other. The transmandibular distractor (TMD) allows for rotation at the temporomandibular joints.

Long-term skeletal effects of mandibular symphyseal distraction osteogenesis. An implant study

The purpose of this study was to investigate the long-term skeletal effects of mandibular symphyseal distraction osteogenesis (MSDO) with a tooth- and bone-borne distraction device, analysed using the metallic implant method. The study sample comprised 20 patients between 15.8 and 25 years of age, with a mean age of 20.01 +/- 2.25 years at the start of treatment. In 12 subjects, titanium implants were inserted in the mandible to analyse mandibular skeletal changes in the short and long term. A custom-made intraoral, tooth- and bone-borne distractor was designed and used. After a latency period of 7 days, the distractor was activated twice daily, by a total amount of 1 mm. Postero-anterior (PA) cephalograms were obtained at the start of distraction and at the end of consolidation (94.95 +/- 5.79 days after surgery) and follow-up periods (21.5 +/- 4.6 months after consolidation). The data were analysed statistically using paired t-tests. The mean amount of screw activation was 8.10 +/- 1.68 mm. The inter-symphyseal and inter-molar implant distances and the bimolar width significantly increased during the consolidation period (P < 0.001) and were maintained at the end of the follow-up. On the other hand, the bicondylar width was markedly decreased (P < 0.05), while no significant skeletal changes were observed in bigonion and biantigonion widths, inter-ramal implant distance, or inter-ramal and implant angles at the end of the consolidation period. The long-term findings of this study indicate that MSDO provides an efficient and stable non-extraction treatment alternative, mainly by increasing the anterior mandibular skeletal and dental arches.

Unilateral Brodie bite treated with distraction osteogenesis

Mandibular widening by distraction osteogenesis has recently been shown to be a very predictable, successful, and stable procedure with limited morbidity. One indication for mandibular widening by distraction osteogenesis is a Brodie bite (scissors or buccal crossbite). This case report demonstrates a technique used to treat a 12-year-old girl with a true unilateral buccal crossbite (no functional shift). It details how distraction osteogenesis can successfully treat unilateral problems with a distractor, a splint, and elastics. Details on this treatment technique have not been previously published.

Corrélation entre les données échographiques et radiographiques dans l’évaluation de la maturation du cal osseux symphysaire après distraction

OBJECTIVE

To search for means of reducing ionizing radiation during treatment planning for transmandibular osteodistraction.

MATERIAL AND METHODS

Eleven patients (6 female, 5 male) underwent combined bimaxillary osteodistraction at a mean age of 18 Years. The following investigations were performed to determine symphyseal callus maturation: occlusal radiographs (O-RX) preoperatively, after the active phase of distraction (mean 27 days); ultrasound investigations (US) after the active and consolidation phase.

RESULTS

US showed calcification foci at the end of the active phase, when O-RX failed to do so. Both US and O-RX detected callus immaturity after 2 Months of consolidation in 1 patient. Both detected bridging ossification one Month later.

DISCUSSION

US can replace radiography in the diagnosis of callus maturation related to distractor removal.

Problems, obstacles and complications with transpalatal distraction in non-congenital deformities

INTRODUCTION

The transpalatal distractor is a bone-borne device that eliminates negative orthodontic effects during and after maxillary expansion. It produces virtually parallel expansion in the coronal plane. Orthodontic appliances can be installed at an earlier date than when tooth-borne expanders are used. Our aim was to improve the technique by reviewing the difficulties encountered during applications in the past.

PATIENTS AND METHODS

The files of 57 patients were analyzed for problems (difficulties requiring surgical intervention), obstacles (difficulties requiring surgical intervention but not interfering with the result), and complications (difficulties not resolved at the end of the treatment).

RESULTS

Twenty-nine difficulties occurred. In 25 cases they were considered to be a 'problem'. Nine problems were surgery related and 16 problems were related to the distraction device itself (14 episodes of loosening of the module, two instances of loss of one osteosynthesis screw). 'Obstacles' occurred in three cases, i.e. loosening of an abutment plate. There was only one 'complication': unilateral infraorbital hyposensibility in a case of a high level corticotomy.

CONCLUSION

The expansion goal was achieved in all patients. Loosening of the module proved to be the major cause of discomfort. The incidence of difficulties has lead to a change in the design of the hardware and in the surgical protocol.