Maxillary canine impactions related to impacted central incisors: two case reports.

J Contemp Dent Pract. 2007;8(6):72-81

Authors: Bayram M, Ozer M, Sener I

AIM: The purpose of this case report is to describe the combined surgical and orthodontic treatment of two cases with an impacted maxillary central incisor and canine in the same quadrant and to discuss the causal relationship between them. BACKGROUND: The most common causes of canine impactions are usually the result of one or more factors such as a long path of eruption, tooth size-arch length discrepancies, abnormal position of the tooth bud, prolonged retention or early loss of the deciduous canine, trauma, the presence of an alveolar cleft, ankylosis, cystic or neoplastic formation, dilaceration of the root, supernumerary teeth, and odontomas. Although impaction of the maxillary central incisor is almost as prevalent as impacted canines its etiology is different. The principal factors involved in causing the anomaly are supernumerary teeth, odontomas, and trauma. REPORTS: Case #1: A 10.5-year-old girl in the early mixed dentition stage presented with a chief complaint of the appearance of her anterior teeth. She had a Class I skeletal pattern and a history of trauma to the maxillary central incisors at age five with premature exfoliation. Radiographs revealed an impacted upper right central incisor in the region of the nasal floor, delayed eruption of the maxillary permanent central incisor, and the adjacent lateral incisor was inclined toward the edentulous space. Treatment was done in two stages consisting of surgical exposure and traction of the impacted central incisor and fixed orthodontic treatment. Case #2: An 11.5-year-old girl presented for orthodontic treatment with the chief complaint of an unerupted tooth and the appearance of her upper anterior teeth. She was in the late mixed dentition period with a Class III skeletal pattern along with an anterior cross-bite with some maxillary transverse deficiency. The maxillary right canine and central incisor were absent, but the maxillary right deciduous canine was still present. Treatment included arch expansion followed by surgical exposure and traction of the impacted teeth and fixed orthodontic treatment. SUMMARY: This case report provides some evidence of a significant environmental influence of an impacted maxillary central incisor on the path of eruption of the ipsilateral maxillary canine. When an impacted maxillary central incisor exists, the maxillary lateral incisor's root might be positioned distally into the path of eruption of the maxillary canine preventing its normal eruption. Ongoing assessment and early intervention might help to prevent such adverse situations from occurring.

PMID: 17846674 [PubMed - indexed for MEDLINE]

Ultrasound bone cutting for surgically assisted rapid maxillary expansion under local anesthesia. Preliminary results.

Minerva Stomatol. 2007 Jun;56(6):359-68

Authors: Robiony M, Polini F, Costa F, Zerman N, Politi M

Surgically assisted rapid maxillary expansion (SARME) is a well-established therapy for correction of maxillary transverse deficiency in adults, when consolidation of sutures has just been completed. It can be performed either under general or under local anesthesia and it can be accomplished with many surgical techniques. One of the most critical steps of SARME is the detachment of the pterygo-maxillary junction, due to the risks connected to such procedure. When required to obtain specific expansion patterns, the pterygo-maxillary separation has been suggested until now only for interventions under general anesthesia, due to the dangerousness and the rawness of this surgical step in awake patients. The authors introduce the use of an ultrasonic bone-cutting device to perform all osteotomic steps of SARME under local anesthesia on an outpatient basis, including pterygo-maxillary detachment. This ultrasonic device is unique in that the osteotomic action occurs only when the tool is employed on mineralized tissues, while it stops on soft tissues. It works in a linear pattern of vibration and it allows precise osteotomies without producing any heat damage to osteotomic surfaces and without any dangerous hammer-related stroke. Due to its precision and safety, this device named Piezosurgery, allows patients to undergo all the steps of SARME under local anesthesia, also without hospitalization.

PMID: 17625493 [PubMed - indexed for MEDLINE]

Maxillary corticotomy and extraoral orthopedic traction in mature teenage patients: a case report.

J Contemp Dent Pract. 2007;8(5):76-84

Authors: Pelo S, Boniello R, Gasparini G, Longobardi G

AIM: The authors' propose to combine the reverse pull headgear with a Delaire type face mask and a maxillary corticotomy to treat a Class III non-growing patient with maxillary retrusion. The aim of this report is to present two cases in which this treatment strategy was successful. BACKGROUND: Several studies suggest the majority of Class III dento-skeletal malocclusions have components of maxillary retrusion. Early treatment of these patients with maxillary protraction devices have shown promising results. Facemask therapy has some important limits. Most important is the optimal timing of treatment between the ages of six to ten years. Closure of the maxillary suture occurs as a child ages which results in an increase of maxillary resistance to protraction. REPORT: A proposed therapy carried out in orthodontic and surgical phases was used in the treatment of two young patients. They were both beyond the optimal age range for the application of the orthopedic device (a girl 15 years old and a boy 16 years old), however, they had not reached the necessary skeletal maturity for orthognathic surgery. SUMMARY: The described technique has the advantage of being quick and easy to perform with a low surgical risk yielding satisfactory results after 15-20 days of therapy instead of the six to nine months associated with traditional procedures.

PMID: 17618333 [PubMed - indexed for MEDLINE]

Mechanical force-induced midpalatal suture remodeling in mice.

Bone. 2007 Jun;40(6):1483-93

Authors: Hou B, Fukai N, Olsen BR

Mechanical stress is an important epigenetic factor for regulating skeletal remodeling, and application of force can lead to remodeling of both bone and cartilage. Chondrocytes, osteoblasts and osteoclasts all participate and interact with each other in this remodeling process. To study cellular responses to mechanical stimuli in a system that can be genetically manipulated, we used mouse midpalatal suture expansion in vivo. Six-week-old male C57BL/6 mice were subjected to palatal suture expansion by opening loops with an initial force of 0.56 N for the periods of 1, 3, 5, 7, 14 or 28 days. Periosteal cells in expanding sutures showed increased proliferation, with Ki67-positive cells representing 1.8+/-0.1% to 4.5+/-0.4% of total suture cells in control groups and 12.0+/-2.6% to 19.9+/-1.2% in experimental/expansion groups (p<0.05). Starting at day 1, cells expressing alkaline phosphatase and type I collagen were seen. New cartilage and bone formation was observed at the oral edges of the palatal bones at day 7; at the nasal edges only bone formation without cartilage appeared to occur. An increase in osteoclast numbers suggested increased bone remodeling, ranging from 60 to 160% throughout the experimental period. Decreased Saffranin O staining after day 3 suggested decreased proteoglycan content in the secondary cartilage. Micro-CT showed a significant increase in maxillary width at days 14 and 28 (from 2334+/-4 microm to 2485+/-3 microm at day 14 and from 2383+/-5 microm to 2574+/-7 microm at day 28, p<0.001). The suture width was increased at days 14 and 28, except in the oral third region at day 28 (from 48+/-5 microm to 36+/-4 microm, p<0.05). Bone volume/total volume was significantly reduced at days 14 and 28 (50.2+/-0.7% vs. 68.0+/-3.7% and 56.5+/-1.0% vs. 60.9+/-1.3%, respectively, p<0.05), indicative of increased bone marrow space. These findings demonstrate that expansion forces across the midpalatal suture promote bone resorption through activation of osteoclasts and bone and cartilage formation via increased proliferation and differentiation of periosteal cells. Mouse midpalatal suture expansion would be useful in further studies of the ability of mineralized tissues to respond to mechanical stimulation.

PMID: 17398175 [PubMed - indexed for MEDLINE]

Surgically assisted rapid maxillary expasion: a preliminar study.

Rev Bras Otorrinolaringol (Engl Ed). 2006 Jul-Aug;72(4):457-61

Authors: do Egito Vasconcelos BC, Caubi AF, Dias E, Lago CA, Porto GG

Surgically assisted rapid maxillary expansion is efficient for the treatment of transverse maxillary deficiencies in skeletally mature patients. AIM: To study two techniques for surgically assisted rapid maxillary expansion: with or without pterygoid plate detachment. MATERIAL AND METHODS: A longitudinal cohort study sample including ten patients aged 18-40 years, with a skeletal transverse discrepancy in the maxilla of more than 4 mm. Two groups were established on a randomized basis, five patients in each group, according to the detachment or absence of detachment of the pterygoid plate. Furthermore, osteotomies of the bilateral zygomatic buttress and the intermaxillary suture were done in both groups. The transverse discrepancy was measured in study models, a posterior-anterior cephalometric radiograph evaluated the superior and inferior zygomatic plane and the inter-tuber distance and an occlusal radiograph evaluated the intermaxillary disjunction in the pre-operative period and 30 days post-operatively. A 7-day period of rest was given after corticotomy before starting expansion with quarter turns once a day. RESULTS: There were no statistically significant differences between pre- and post-operative measurements. CONCLUSION: There are few randomized control trials in literature comparing the two techniques for surgically maxillary expansion. Further studies with a larger sample are required.

PMID: 17143423 [PubMed - indexed for MEDLINE]

[Cephalometric study of alterations induced by maxillary slow expansion in adults]

Rev Bras Otorrinolaringol (Engl Ed). 2006 Mar-Apr;72(2):166-72

Authors: Machado J&#xFA;nior AJ, Crespo AN

Maxilla expansion is a procedure that aims at increasing the maxillary dental arch to correct occlusal disharmony. Largely used in children, its efficacy in adults, when craniofacial growth has attained bone maturity, is controversial. AIM: The present study has the objective of evaluating cephalometric modifications resulting from maxilla expansion in adult patients, observing the following linear measurements: facial width, nasal width, nasal height, maxillary width, mandibular width and maxillary molar width. MATERIAL AND METHODS: The sample was composed of 24 frontal teleradiographs, taken before and immediately after the expansions, from 12 male and female patients aged between 18 years and two months and 37 years and eight months. All patients were submitted to slow expansion of the maxillary bones by means of an appliance used in the technique named "dynamic and functional maxillary rehabilitation". Wilcoxon paired statistical test was used for related samples with a 5% significance level. RESULTS: There was a mean increase of 1.92 mm in nasal width and 2.5 mm in nasal height. As regards the linear measurements maxillary and mandibular width, the mean increase was 2.42 mm and 1.92 mm, respectively. A mean increase of 1.41 mm was found for facial width and 2.0 mm for maxillary molar width, alterations which were statistically significant, the mean time was 5.3 months. CONCLUSION: Based on the results obtained, it may be concluded that the use of maxillary expansion induces increase of the facial measurements studied in adults.

PMID: 16951848 [PubMed - indexed for MEDLINE]

Orthodontic and orthopaedic changes associated with treatment in subjects with Class III malocclusions.

Eur J Orthod. 2006 Oct;28(5):496-502

Authors: Kama JD, Ozer T, Baran S

The aim of this study was to determine the cephalometric changes in subjects with Class III malocclusions after rapid palatal expansion (RPE) and facemask treatment. The 30 subjects presented with developing Class III malocclusions. The treatment group comprised 15 patients (eight girls and seven boys, mean age 11 years 6 months) who had undergone RPE and facemask therapy. The control group consisted of nine girls and six boys with a mean age of 11 years 8 months. Radiographs were take at the same time intervals for both groups, and the average treatment time was 15 months. A Wilcoxon test was used to determine significant differences before and after treatment, and a Mann-Whitney U-test to analyse differences between the treatment and control groups. In the sagittal plane, significant changes were observed in both groups. In the treatment group, the following dimensions increased significantly: A perpendicular to FHp (P < 0.001), ANS-PNS (P < 0.01), 6 perpendicular to FHp (P < 0.05); in the control group Go-Gn (P < 0.05) increased significantly. In the treatment group, SN/Go-Gn and SN/ANS-PNS had higher values and this finding was significant (P < 0.05). Managing developing Class III malocclusions with RPE and maxillary protraction presents favourable results, such as vertical and sagittal displacement of point A.

PMID: 16772318 [PubMed - indexed for MEDLINE]

The Dynamax system: a new orthopaedic appliance and case report.

J Orthod. 2006 Jun;33(2):78-89

Authors: Bass NM

The Dynamax appliance is a treatment modality for the correction of the Skeletal II malocclusion characterized by a mandibular retrusion. Progressive mandibular advancement, maxillary expansion, control of maxillary growth, incisor torque and control of vertical facial development are incorporated into a two-part appliance. The design facilitates laboratory construction, clinical handling and patient acceptability. A prefabricated spring module forms the basis of the appliance, allowing both maxillary expansion and mandibular advancement. An easily adjustable progressive forward position of the lower jaw makes a construction bite unnecessary. The spring module provides most of the structure of the appliance so that minimal acrylic is required and the appliance is fully contained within the freeway space. Contact between the upper and lower parts of the appliance occurs posteriorly in the lingual sulcus. Here the depth permits an extended vertical contact, to maintain a protrusive mandibular position throughout the range of mandibular opening, including during sleep. The lower portion of the appliance may be fixed or removable and multibracket treatment can be carried out in one or both arches at the same time as the orthopaedics.

PMID: 16751429 [PubMed - indexed for MEDLINE]

Evaluation of maxillary protraction and fixed appliance therapy in Class III patients.

Eur J Orthod. 2006 Aug;28(4):383-92

Authors: Arman A, Ufuk Toygar T, Abuhijleh E

The aim of this study was to examine the dentofacial changes in Class III patients treated with fixed appliances subsequent to rapid maxillary expansion (RME) and facemask therapy. The material consisted of the cephalograms and hand-wrist films of 14 (9 girls, 5 boys) skeletal Class III and 15 (10 girls, 5 boys) untreated subjects obtained at the beginning of treatment/observation T1, immediately after orthopaedic therapy T2, and at the end of the observation period T3. The mean pre-treatment/control ages were approximately 11.5 years and the observation period was 3 years T2-T1: 1 year, T3-T2: 2 years). The cephalometric films were analysed according to the structural superimposition method of Bj&#xF6;rk. All tracings were double-digitized and the measurements were calculated by a computer program. Intragroup changes and intergroup differences were statistically analysed. Forward movement of the maxilla (P < 0.01), backward movement and rotation of the mandible, an increase in the ANB angle (P < 0.001), lower face height and overjet (P < 0.001), a decrease of overbite, and an improvement in the sagittal lip relationship (P < 0.01) presented significant intergroup differences between T2 and T1. During the second phase of treatment T3-T2, although not statistically significant, forward movement of the maxilla was less than in the control subjects. Overall changes during the observation period T3-T1 revealed that correction was mainly due to favourable changes in the mandibular and dentoalveolar components of the discrepancy, while these in maxillary position were not different from the control group. The soft tissue profile improved significantly (P < 0.001) in the treatment group. Comparison with the Class I controls at the end of the observation period confirmed that some Class III characteristics still remained in the treated patients.

PMID: 16731542 [PubMed - indexed for MEDLINE]

Correlation between transverse expansion and increase in the upper arch perimeter after rapid maxillary expansion.

Braz Oral Res. 2006 Jan-Mar;20(1):76-81

Authors: Claro CA, Abr&#xE3;o J, Reis SA, de Fantini SM

The purpose of the present study was to assess the correlation between transverse expansion and the increase in upper arch perimeter, after maxillary expansion. Dental casts of eighteen patients were obtained before treatment and again five months after maxillary expansion. Measurements of intermolar width, intercanine width, arch length and arch perimeter were made with a digital caliper on photocopies taken from the dental casts. After assessment of the method error, a multiple regression model was developed following the identification of the best subset of variables. The resulting equation led to the conclusion that the increase in arch perimeter is approximately given by the addition of 0.54 times the intercanine expansion, and 0.87 times the arch length alteration.

PMID: 16729179 [PubMed - indexed for MEDLINE]

BOS MOrth Cases Prize 2004.

J Orthod. 2006 Mar;33(1):7-21

Authors: Uÿs JO

This paper describes the clinical orthodontic treatment of 2 cases that were successfully entered for the 2004 American Orthodontics MOrth Cases Prize. The first case is that of a patient presenting with a Class III malocclusion treated with rapid maxillary expansion and protraction headgear followed by fixed appliance therapy. The second case demonstrates the use of fixed appliances to correct a moderate Class II division I malocclusion.

PMID: 16514129 [PubMed - indexed for MEDLINE]

An application of a splint purposeful resin-bonded fixed partial denture after orthodontic treatment: a case report.

J Contemp Dent Pract. 2006 Feb 15;7(1):141-9

Authors: Baydaş B, Denizoglu S

An adult male patient who had lost his maxillary left central incisor seven years ago in a traffic accident presented with a chief complaint about his unaesthetic appearance associated with the loss of his maxillary left central incisor space, a Class III molar occlusion, and an anterior open bite malocclusion due to tongue-thrust swallowing. Fixed orthodontic treatment was rendered following fan-type expansion of the maxilla. A Maryland bridge as a minimally invasive dentistry approach was used as a retention appliance and the patient's aesthetic appearance was restored.

PMID: 16491157 [PubMed - indexed for MEDLINE]

Sagittal airway dimensions following maxillary protraction: a pilot study.

Eur J Orthod. 2006 Apr;28(2):184-9

Authors: Sayinsu K, Isik F, Arun T

The relationship between changes in the position of the maxillary structures caused by maxillary protraction therapy and airway dimensions have not been investigated as comprehensively as the accompanying skeletal changes. The purpose of this study was to examine the effects of rapid palatal expansion (RPE) used in conjunction with maxillary protraction headgear on the sagittal dimension of the airway. The treatment sample consisted of 19 Class III patients (12 girls, 7 boys) with a mean age of 10.51 +/- 1.15 years, presenting with maxillary retrognathism. A cap splint type rapid palatal expander that had hooks between the upper lateral and canine teeth was used intraorally, and a Petit type facemask device extraorally, for an average of 6.78 +/- 0.93 months. Pre- and post-treatment cephalometric radiographs were evaluated. The results of the study revealed that point A moved anteriorly. The palatal plane showed a counter-clockwise rotation matched by the clockwise rotation of the mandible and an accompanying decrease in SNB angle. The vertical parameters showed a statistically significant increase. The head was in a more extensive position in relation to the cervical vertebrae. The nasopharyngeal airway measurements (PNS-ad1, PNS-ad2) showed an increase of 2.71 +/- 3.35 and 3.03 +/- 2.37 mm, respectively. These results demonstrated that limited maxillary widening together with protraction of the maxilla, improve nasopharyngeal but not oropharyngeal airway dimensions in the short term.

PMID: 16464873 [PubMed - indexed for MEDLINE]

Meta-analysis of immediate changes with rapid maxillary expansion treatment.

J Am Dent Assoc. 2006 Jan;137(1):44-53

Authors: Lagrav&#xE8;re MO, Heo G, Major PW, Flores-Mir C

BACKGROUND: The authors conducted a literature review to evaluate immediate transverse, anteroposterior, and vertical dental and skeletal changes produced by rapid maxillary expansion (RME). TYPES OF STUDIES REVIEWED: The authors reviewed clinical trials that assessed immediate dental and/or skeletal changes after RME using cephalometric analysis, model casts or both. No surgical or other simultaneous treatment was accepted during the evaluation period. RESULTS: The authors searched electronic databases and found 31 articles that met the initial inclusion criteria. The authors later rejected 12 of these articles because they did not report immediate changes, three because they lacked detailed descriptions of their results and two because of their nonconventional appliance designs. Fourteen articles satisfied th final inclusion criteria; however, they had methodological deficiencies. CLINICAL IMPLICATIONS: The greatest changes resulting from RME in the studies analyzed were dental and skeletal transverse changes. Few vertical and anteroposterior immediate changes were statistically significant, though they probably are not clinically important.

PMID: 16456998 [PubMed - indexed for MEDLINE]

A comparative study of dental arch widths: extraction and non-extraction treatment.

Eur J Orthod. 2005 Dec;27(6):585-9

Authors: Işik F, Sayinsu K, Nalbantgil D, Arun T

The aim of this study was to determine the pre- and post-treatment width changes in the canine, premolar and molar regions in subjects treated with extraction of four first premolars, non-extraction, and non-extraction with rapid maxillary expansion (RME). Pre- and post-treatment orthodontic study models of 60 females (13.83 +/- 2.77 years) and 24 males (14.33 +/- 2.67 years) who underwent comprehensive orthodontic therapy were evaluated. Forty-two were treated non-extraction with fixed appliance therapy, 15 non-extraction with RME, and 27 with extraction of the first premolars. In addition to standard descriptive statistical calculations, one way ANOVA was used for comparison of the groups, and the post hoc Tukey multiple comparison test for comparison of the subgroups. The results revealed that the distance between the upper canines was not affected by the treatment modality. Upper premolar and molar arch widths increased more in the non-extraction subjects when compared with those with extractions, with the greatest increase in patients with RME. In the lower canine area the extraction group showed the widest arch width at the end of treatment. There was also a 0.60 mm decrease in the lower canine width in the non-extraction group. A decrease was found in lower inter-premolar and molar distances due to consolidation of the extraction spaces. When making a decision between non-extraction with maxillary expansion and extraction treatment modalities in borderline cases where there is constriction in the upper inter-premolar distance, apart from taking profile values into consideration, it should be borne in mind that expansion treatment can be helpful in achieving a wider arch form.

PMID: 16257988 [PubMed - indexed for MEDLINE]

Changes in natural head position observed immediately and one year after rapid maxillary expansion.

Eur J Orthod. 2006 Apr;28(2):126-34

Authors: McGuinness NJ, McDonald JP

Rapid maxillary expansion (RME) has been shown to increase nasal permeability and reduce nasal airway resistance. A number of studies have examined the relationship between RME and the change in airway resistance, or the relationship between airway resistance and natural head position (NHP). Few studies, to date, have examined the relationship between RME and the change in NHP resulting from the consequent change in airway resistance. A sample of 43 adolescent patients with uni- or bilateral crossbite in the permanent dentition underwent RME as part of normal orthodontic treatment. Cephalograms in NHP were taken before, immediately after expansion, and one year after RME. No significant changes in the craniofacial angles were observed immediately after expansion. One year post-expansion, however, NSL/VER had reduced by 3.14 degrees (P < 0.01), OPT/HOR by 2.13 degrees (P < 0.05), and CVT/HOR by 2.55 degrees (P < 0.05). The results of this study suggest an ongoing change in head posture possibly due to a change in the mode of breathing from oral to nasal as a result of RME, thereby contributing to a change in craniofacial development, supporting and adding to the soft tissue stretching hypothesis.

PMID: 16157633 [PubMed - indexed for MEDLINE]

Changes in clinical crown height as a result of transverse expansion of the maxilla in adults.

Eur J Orthod. 2005 Apr;27(2):121-8

Authors: Bassarelli T, Dalstra M, Melsen B

The risk of developing bony dehiscence and gingival recession may lead clinicians to prefer extraction to expansion in borderline cases. The purpose of this research was to compare changes in clinical crown height that occur at the buccal aspect of the maxillary lateral teeth of adult patients in which the transverse dimension was increased with those occurring if no expansion had been performed. Secondly it was the intention to identify factors increasing the risk of development of gingival recessions.The material comprised the pre- and post-treatment study casts from two groups of 50 adult patients. In one group an average transverse expansion of 3 mm was performed while in the other no change in the arch width was generated during treatment. Clinical crown heights of the two groups before and after treatment were compared with a Student's t-test and correlation analysis was used to determine whether any demographic or treatment-related parameters could be applied to predict an increase in clinical crown height.The increase in transarch width was greater in males (2.4-3.4 mm) than in females (1.8-2.5 mm), and greater at the level of the premolars than at the molars. No significant increase in buccal crown height could be identified. The increase in width was, however, related to buccal tipping as a positive correlation was found between the amount of expansion and tipping (P < 0.01). No detrimental effect of slow maxillary expansion could be demonstrated.

PMID: 15817617 [PubMed - indexed for MEDLINE]

A randomized controlled trial comparing the quadhelix and the expansion arch for the correction of crossbite.

J Orthod. 2005 Mar;32(1):29-35

Authors: McNally MR, Spary DJ, Rock WP

OBJECTIVE: To compare the use of the quadhelix and the expansion arch for the correction of crossbite. DESIGN: A prospective randomized clinical trial supported by preliminary laboratory measurements. The null hypothesis was that there was no difference in the clinical effectiveness of the two expansion devices in terms of crossbite correction. SETTING: Queen's Hospital, Burton on Trent and The University of Birmingham, School of Dentistry.Participants: The first 60 patients on the orthodontic waiting list at Queen's Hospital who required expansion of the maxillary arch as part of the treatment plan were allocated to be treated with either a quadhelix or an expansion arch by random allocation. Twenty-eight and 27 members of each respective group completed the study. MATERIALS: Commercial quadhelix arches (3M Unitek) and custom-made expansion arches METHODS: The force produced by the type of expansion arches used in the study was measured in the laboratory to be 1.8 N at 10 mm of expansion. Quadhelix arches of sizes 2 and 3 were found to produce equivalent forces at 5 and 7 mm of expansion respectively. Either expansion device was fitted to the 60 participants according to random allocation and expanded by the standard amount. Intermolar and intercanine expansion was measured after 4, 8 and 12 weeks. Patient opinion was assessed by using a questionnaire. RESULTS: The quadhelix and the expansion arch were equally effective in producing expansion (p>0.05). After 12 weeks, the two types of archwire had produced mean intermolar expansions of 4.54 and 5.09 mm and intercanine expansions of 1.41 and 2.12 mm, respectively. Both types of arch were reported as uncomfortable by a majority of patients, the quadhelix affected mainly the tongue and the expansion arch the cheeks. The appearance of the quadhelix was disliked by 25% of participants, while 70% disliked the expansion arch. CONCLUSIONS: The null hypothesis was confirmed. However, the expansion arch had several advantages that made it a cheap alternative to the quadhelix for crossbite expansion, because it can be made and fitted at the chairside.

PMID: 15784941 [PubMed - indexed for MEDLINE]

A randomized controlled trial comparing the quadhelix and the expansion arch for the correction of crossbite.

J Orthod. 2005 Mar;32(1):26

Authors: Harrison J

PMID: 15784939 [PubMed - indexed for MEDLINE]

Skeletal and dental changes with fixed slow maxillary expansion treatment: a systematic review.

J Am Dent Assoc. 2005 Feb;136(2):194-9

Authors: Lagrav&#xE8;re MO, Major PW, Flores-Mir C

BACKGROUND: The authors were not able to identify any systematic reviews or meta-analysis on the dental or skeletal changes associated with slow maxillary expansion (SME). Therefore, they conducted a study to evaluate skeletal and dental changes after fixed SME treatment in orthodontic patients with constricted arches. METHODS: The authors included in their evaluation clinical trials that assessed skeletal and dental arch changes through measurements on dental casts or cephalometric radiographs. The authors did not consider trials involving surgical or other simultaneous treatment interventions during the active expansion period. RESULTS: With the help of a health sciences librarian, the authors searched the following electronic databases: PubMed, MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, Evidence Based Medicine Reviews (Cochrane Database of Systematic Reviews, American College of Physicians Journal Club, Database of Abstracts of Reviews of Effects and Cochrane Central Register of Controlled Trials), EMBASE Excerpta Medica, Thomsen's ISI Web of Sciences and LILACS. Eight articles met the initial inclusion criteria. The authors found that a significant deficiency in the studies was the lack of a control group to factor out changes in the dental arch and skeletal structures associated with normal growth. CONCLUSIONS AND CLINICAL IMPLICATIONS: The authors found only a lower level of evidence. Therefore, they could make no strong conclusions on dental or skeletal changes that occurred after SME treatment. Clinicians need to rely on their clinical experience, experts' opinions and the presented limited evidence concerning SME treatments.

PMID: 15782523 [PubMed - indexed for MEDLINE]

A case of Antley-Bixler syndrome with severe skeletal Cl. III malocclusion.

Bull Tokyo Dent Coll. 2004 May;45(2):87-93

Authors: Tsuchiya Y, Sueishi K, Yatabe K, Yamaguchi H

Antley-Bixler syndrome is a disorder characterized by craniosynostosis, midface hypoplasia, choana blockade, and radiohumeral synostosis. However, the features of occlusion remain unclear. In this paper, we report a case of Antley-Bixler syndrome, a 7-year-old boy, from the viewpoint of orthodontics. From lateral cephalometric head film analysis, remarkable retardation of the anterior subcranial base, infraorbitale, and maxilla were notable, as was vertical growth restriction of the maxilla. The choana blockade tendency was also recognized. Moreover, although reverse occlusion was present, a mandibular retrognathic tendency was also present, and a short ramus mandible, remarkable mandibular vertical growth pattern, and skeletal open bite were present. In the dentition, two of the lower incisors were missing, and the present lower incisors were large. Maxillary and mandibular first molars were delayed in eruption. For treatment, the solutions to such remarkable skeletal problems were limited by the insufficiency of recovery of cranial formation after the operation. We planned a non-surgical treatment to expand the maxilla. It will be necessary to continually consider the treatment of his malocclusion as he continues to grow.

PMID: 15536859 [PubMed - indexed for MEDLINE]

The William Houston Medal of the MOrth of the Royal College of Surgeons of Edinburgh 2003 and the BOS MOrth Cases Prize 2003.

J Orthod. 2004 Sep;31(3):169-80

Authors: O'Dwyer JJ

This paper describes the orthodontic treatment of 2 cases that were presented by the winner of the William Houston Medal of the MOrth of the Royal College of Surgeons of Edinburgh at the June 2003 diet of the examination. The cases were also successful presented for the British Orthodontic Society MOrth Cases Prize 2003.

PMID: 15489361 [PubMed - indexed for MEDLINE]

A clinical comparison of the quadhelix appliance and the nickel titanium (tandem loop) palatal expander: a preliminary, prospective investigation.

Eur J Orthod. 2004 Aug;26(4):411-20

Authors: Donohue VE, Marshman LA, Winchester LJ

Maxillary expansion using either a quadhelix appliance (Qx) or a nickel titanium palatal expander (Nt) was prospectively compared in 28 consecutive new patients (19 female, nine male) presenting with posterior buccal segment crossbites. Study models taken at each activation were measured to determine the mean maxillary expansion efficacy (Emax) and the mean expansion rate (m(max)) across the first molars and first premolars. Patient discomfort was assessed using visual analogue scores, and cost-effectiveness was also considered. Neither Emax nor m(max) differed significantly between Qx and Nt across either the first molars or the first premolars. However, both Emax and m(max) were significantly greater across the first molars than across the first premolars only with Qx (Emax: 8.4 +/- 0.7 mm versus 5.1 +/- 0.6 mm, P = 0.001; m(max): 0.09 +/- 0.005 mm/day versus 0.05 +/- 0.006 mm/day, P = 0.0001). In addition, greater variance was apparent in m(max) with Nt than with Qx across both the first molars and the first premolars. Overall, Qx and Nt elicited similar discomfort. However, significantly less was reported with Nt on days 6 (P = 0.04) and 7 (P= 0.03) following the second 'activation'. These preliminary results suggest that Qx and Nt are equally efficacious maxillary expanders. However, Qx expansion appeared significantly more controlled, as well as more individually predictable in expansion rate. Overall, Qx and Nt probably elicit similar discomfort, but significantly less discomfort may be seen with Nt following the second activation. Finally, because more than one appliance is invariably required with Nt, Qx expansion is potentially less costly.

PMID: 15366386 [PubMed - indexed for MEDLINE]

Skeletal and dental changes following surgically assisted rapid palatal expansion.

Eur J Orthod. 2004 Aug;26(4):403-9

Authors: Byloff FK, Mossaz CF

The purpose of this study was to analyse the changes produced by surgically assisted rapid palatal expansion (SARPE) longitudinally on 14 patients aged between 18 and 41 years. A pre-fabricated Hyrax appliance was cemented prior to the surgical intervention, which consisted of a maxillary buccal corticotomy with pterygoid separation. Models and postero-anterior (PA) headfilms were taken before expansion (T1), at the end of expansion (T2), at the end of retention (T3) and at least 1 year post-surgery (T4). Overall expansion and relapse were measured directly on the casts. Transverse distances increased more at the first molars (8.7 mm) and premolars (8.1 and 8.3 mm) than in the canine (5.2 mm) and second molar (5.5 mm) region. Minimal relapse occurred during the retention phase. The arch width decreased more during the post-retention period, with more pronounced reduction at the teeth used as anchorage during the expansion procedure (-2.0 mm for the first premolars and -2.6 mm for the first molars). The mean total dental relapse was 28 per cent. PA radiographic analysis for angular changes showed 9.6 degrees of lateral tipping per side during expansion. One-third of this movement relapsed during the retention period (-3.3 degrees) and this trend (-6.0 degrees) continued during the post-retention phase to reach practically the original value at T1. Skeletal changes monitored on the PA headfilms were minimal with great individual variation. The mean expansion measured in the proximity of the osteotomy site was only 1.3 mm. From this amount, 0.4 mm was lost during the retention and post-retention periods. Based on these findings, it appears that maxillary skeletal expansion by SARPE is mainly a lateral rotation of the two maxillary halves with only minimal horizontal translation.

PMID: 15366385 [PubMed - indexed for MEDLINE]

Evaluation of nasal airway resistance during rapid maxillary expansion using acoustic rhinometry.

Eur J Orthod. 2004 Aug;26(4):397-401

Authors: Doruk C, S&#xF6;kücü O, Sezer H, Canbay EI

The purpose of this study was to evaluate nasal airway resistance (NAR) during rapid maxillary expansion (RME) using acoustic rhinometry (AR). The sample comprised 22 children (13 girls and nine boys) with maxillary constriction. The mean age was 12.9 +/- 1.54 years and all patients were found to have normal nasal cavities following anterior rhinoscopic examination. A modified bonded splint type RME appliance was used for expansion. AR was used to measure NAR before (T1), during (T2) and after (T3) expansion, and at the end of retention (T4). Each AR recording was performed, for each patient, with and without the use of a decongestant. Subjective evaluation of reported changes in nasal breathing were also undertaken at T3. The results showed that NAR was significantly reduced with the use of RME, with the main decrease observed during expansion (P < 0.05). The use of a decongestant was not found to have any effect on the results. Subjective evaluation showed that 59 per cent of patients considered that their nasal breathing had improved following RME.

PMID: 15366384 [PubMed - indexed for MEDLINE]

Feasibility and long-term stability of surgically assisted rapid maxillary expansion with lateral osteotomy.

Eur J Orthod. 2004 Aug;26(4):391-5

Authors: Anttila A, Finne K, Keski-Nisula K, Somppi M, Panula K, Peltomäki T

Surgically assisted rapid maxillary expansion (SARME) has become a widely used and acceptable means to expand the maxilla in adolescents and adult patients. The method takes advantage of bone formation at the maxillary edges of the midline, while they are separated by an external force. The purpose of the present retrospective investigation was to evaluate the feasibility and long-term stability of maxillary expansion in patients in whom lateral pre-expansion osteotomy had been performed. The subjects were 20 patients (14 females, six males, mean age 30.6 years, range 16.2-44.2 years) whose malocclusions were treated solely or partly with SARME during 1988-1996. Two orthodontists carried out the post-orthodontic expansion treatment. The surgical technique followed a minimally invasive osteotomy on the lateral maxillary walls. Study models were obtained before surgery (T1), once expansion and the following orthodontic treatment were completed, before possible second-stage osteotomy (T2), and at long-term follow-up (T3). Using the study models, the width of the dental arch was measured with a digital sliding calliper. In addition, transverse occlusal relationships were examined at each time point. The results indicated that (1) SARME is possible when the minimally invasive operation technique is used, (2) long-term stability of maxillary expansion following the present technique compares favourably with the widening and stability achieved with other, more invasive, osteotomies. With age, several possible uncertainties are introduced to affect the course of SARME adversely. Therefore, more extensive osteotomies can be recommended in older patients.

PMID: 15366383 [PubMed - indexed for MEDLINE]

Sleep apnea.

J Am Dent Assoc. 2004 May;135(5):550; author reply 550, 552

Authors: Shapira IL

PMID: 15202740 [PubMed - indexed for MEDLINE]

Evidence-based orthodontics for the 21st century.

J Am Dent Assoc. 2004 Feb;135(2):162-7; quiz 227-8

Authors: Ackerman M

BACKGROUND: This article examines some of the data-driven advances in clinical orthodontics and how they might influence the decision-making process in the specialty. TYPES OF STUDIES REVIEWED: Nearly 100 years of orthodontic study has focused on two issues: one-phase versus two-phase treatment of Class II malocclusion and extraction versus nonextraction treatment of arch perimeter deficiencies. The author addresses these issues by presenting data from the first randomized clinical trial in orthodontics and from a survey of the current literature. RESULTS: The clinical trial involved subjects who had Class II malocclusion. The researchers who conducted the trial found no difference in the quality of the dental occlusion between the children who had early treatment and those who did not, as judged by both an occlusal index (Peer Assessment Rating scores) and the percentages of the subjects with excellent and less-than-optimal outcomes. Early treatment did not reduce the eventual need for orthognathic surgery. In a separate study, a researcher reported that the maxillary arch perimeter could be increased by 3 to 4 millimeters by using rapid palatal expansion, or RPE, providing space for incisor alignment to resolve crowding. The author concluded that any added benefit of RPE treatment in patients without a crossbite might be "challenging to define." CLINICAL IMPLICATIONS: The challenge facing orthodontists in the 21st century is the need to integrate the accrued scientific evidence into clinical orthodontic practice.

PMID: 15005431 [PubMed - indexed for MEDLINE]

[Treatment of maxillary deficiency with the combination of rapid maxillary expansion and maxillary protraction]

Shanghai Kou Qiang Yi Xue. 2003 Aug;12(4):310-2

Authors: Ma L, Chen LL, Xiao WW

PMID: 14966654 [PubMed - indexed for MEDLINE]

[The advancements in correction of adult transverse maxillary deficiency]

Shanghai Kou Qiang Yi Xue. 2003 Oct;12(5):370-3

Authors: Pan XG, Fang B, Qian YF, Tang YS

PMID: 14966615 [PubMed - indexed for MEDLINE]

Class III Twin Blocks: a case series.

J Orthod. 2003 Sep;30(3):197-201

Authors: Kidner G, DiBiase A, DiBiase D

OBJECTIVE: To evaluate the use of Class III Twin Blocks for the early treatment of Class III malocclusion. DESIGN: Retrospective analysis. Subjects and Method: 14 subjects were consecutively treated with a modified version of the Class III Twin Block appliance. Lateral cephalometric radiographs taken at the start and end of treatment were assessed digitally. RESULTS: The mean age of subjects was 10 years and mean treatment time was 6.6 months. The cephalometric analysis of changes during treatment shows proclination of the upper incisors [mean 5.1 degrees, SD 5.1], retroclination of the lower incisors [mean -4.5 degrees, SD 3.9], reduction in angle SNB [mean -1.3 degrees, SD 1.8] and an increase in the maxillary/ mandibular planes angle (mean 2.1 degrees, SD 2.2]. Average cephalometric digitizations and photographs of a clinical case are shown. CONCLUSIONS: Class III Twin Blocks can be used successfully for early treatment of Class III malocclusion. A randomly allocated prospective study is required to fully evaluate the efficacy of this appliance.

PMID: 14530416 [PubMed - indexed for MEDLINE]

The William Houston Gold Medal Prize in the M.Orth. Exam of the Royal College of Surgeons of Edinburgh held in Edinburgh, 2000.

J Orthod. 2003 Sep;30(3):183-95

Authors: Davies KL

PMID: 14530415 [PubMed - indexed for MEDLINE]

Quantitative effects of a nickel-titanium palatal expander on skeletal and dental structures in the primary and mixed dentition: a preliminary study.

Eur J Orthod. 2003 Aug;25(4):401-10

Authors: Ferrario VF, Garattini G, Colombo A, Filippi V, Pozzoli S, Sforza C

The present study analysed the six-month effects of a nickel-titanium (NiTi) palatal expander on the dental and palatal structures of four primary (mean age 5.8 years) and nine mixed dentition children (mean age 8.7 years), with a posterior unilateral crossbite. Standardized dental and palatal landmarks were digitized using a three-dimensional (3D) electromagnetic instrument. Collected data were analysed with geometric-mathematical models. During a six-month interval, the natural growth and development of the dental arches and hard tissue palate was negligible, as assessed in seven control children (two in the primary dentition, mean age 4.4 years; five in the mixed dentition, mean age 7.7 years). In all children the crossbite was completely corrected. Indeed, dental expansion was always more than or corresponded to the palatal expansion. A smoothing of the size-independent (shape) palatal curvature in the transverse plane was observed. No differences in maximum palatal height were noted. Symmetrical derotation of the anchorage teeth in a distal direction occurred in almost all children. The inclination of the facial axis of the clinical crown (FACC) in the anatomical transverse plane of those teeth with differences between dental and palatal expansion always showed significant modifications (vestibular inclination up to 16.7 degrees). The clinical crown height of anchorage teeth remained nearly the same in all patients. No significant modifications in mandibular arch size were observed. The increase in maxillary arch width, especially in younger children, was probably due to a combination of different effects: opening of the midpalatal suture, tipping of the alveolar process, and molar tipping.

PMID: 12938847 [PubMed - indexed for MEDLINE]

Dental tipping and rotation immediately after surgically assisted rapid palatal expansion.

Eur J Orthod. 2003 Aug;25(4):353-8

Authors: Chung CH, Goldman AM

The purpose of this investigation was to evaluate the effects of dental tipping and rotation immediately after surgically assisted rapid palatal expansion (SARPE). Fourteen patients (10 females, four males; mean age 25.6 years) who required a SARPE procedure were available for this study. A palatal expander appliance was cemented on four abutment teeth (first premolars and first molars) of each patient 1 week prior to surgery. Maxillary study models were taken before surgery and 2-3 weeks after full expansion (7 mm). Each model was trimmed to have the base parallel to its occlusal plane. From an occlusal view, measurements were made to determine if the abutment teeth underwent rotation from SARPE. From a postero-anterior view, the abutment teeth were examined for any tipping effect due to SARPE. The results showed that from pre- to post-expansion, the two first premolars displayed 2.32 +/- 8.29 degrees of mesiobuccal rotation (P > 0.05) and the two first molars displayed 3.09 +/- 5.89 degrees of mesiobuccal rotation (P > 0.05). Each first premolar showed 6.48 +/- 2.29 degrees of buccal tipping (P < 0.05) and each first molar 7.04 +/- 4.58 degrees of buccal tipping (P < 0.05). SARPE induced a slight mesiobuccal rotation (P > 0.05) and significant buccal tipping of the first premolars and the first molars (P < 0.05). Some overexpansion is suggested to counteract the relapse effect of buccal tipping of the posterior teeth that takes place during SARPE.

PMID: 12938840 [PubMed - indexed for MEDLINE]

Orthodontic treatment for jaw deformities in cleft lip and palate patients with the combined use of an external-expansion arch and a facial mask.

Bull Tokyo Dent Coll. 2002 Nov;43(4):223-9

Authors: Sakamoto T, Sakamoto S, Harazaki M, Isshiki Y, Yamaguchi H

Patients with cleft lip and palate can suffer from contraction of the maxillary arch and anterior cross-bite accompanied by skeletal growth retardation. We use an appliance called an external-expansion arch and induce maxillary protraction using a facial mask in order to correct the anterior cross-bite and maxillary retrusion. In this paper, the method of application of these appliances and the effects of this therapy are reported here. The external-expansion arch consists of a labial wire, bands and a sectional arch. The 0.045-inch stainless steel wire extends along the maxillary dental arch. Hooks are soldered immediately distal to the lateral incisor and the distal leg of the vertical loop. The brackets are bonded to the maxillary anterior teeth, and a 0.016 x 0.016 inch sectional arch is set. The external-expansion arch is inserted into the headgear tube and ligated with the sectional arch using elastic thread. The maxillary bone is pulled by use of the facial mask and the elastic band. For traction, the force is about 300 g on each side, applied parallel to the occlusal plane or slightly downward. The duration of use is 8 to 12 hours per day. The external-expansion arch has several advantages: it can be applied from the early period of Hellman's dental age IIIA or IIC to improve anterior cross-bite. As it is easy to expand the anterior teeth and move individual teeth to the labial and buccal sides, establishment of a dental arch from severe collapse is not difficult. When an expanding device such as the Quad-helix is incorporated, lateral expansion becomes easier. Furthermore, it is easy to control the teeth vertically, and patient compliance is not necessary. Hence, this method is effective as a phase 1 treatment for orthodontic patients with cleft lip and palate characterized by maxillary retardation.

PMID: 12687727 [PubMed - indexed for MEDLINE]

The BOS intercollegiate M Orth prize of the Royal Colleges of England and Glasgow 2000.

J Orthod. 2002 Sep;29(3):173-80

Authors: Ismail S

PMID: 12218193 [PubMed - indexed for MEDLINE]

Chair-side procedure for connecting transpalatal arches with palatal implants.

Eur J Orthod. 2002 Aug;24(4):337-42

Authors: Crismani AG, Bernhart T, Baier C, Bantleon HP, Kucher G

The present investigation examined a chair-side procedure for connecting a transpalatal arch (TPA) with palatal implants, which does not involve any laboratory work. This new technique was compared with the standard procedure in terms of the number of steps, the time required, and the cost. The total chair-side time needed with the standard procedure was 38 minutes, with the material costs amounting to [symbol: see text] 159.6. With the chair-side procedure the total time required was 55 minutes, and the cost of the material totalled [symbol: see text] 34.1. The chair-side procedure was derived from orthodontic treatment concepts and is independent of laboratory input. Its major advantage is that it does not require transfers, which necessitate additional steps. These steps, which are inevitable with the standard procedure, resulted in an unexpectedly high cost level and increased the total cost. The difference in the cost of the material between the two procedures amounted to [symbol: see text] 125.5 and timewise the difference was 17 minutes. Whilst TPA-implant connections can be made with both the standard and chair-side procedures, the standard procedure, although taking considerably less chair-side time, was four times more expensive than the chair-side procedure.

PMID: 12198863 [PubMed - indexed for MEDLINE]

Thin-plate spline analysis of the short- and long-term effects of rapid maxillary expansion.

Eur J Orthod. 2002 Apr;24(2):143-50

Authors: Franchi L, Baccetti T, Cameron CG, Kutcipal EA, McNamara JA

The aim of this study was to investigate the short- and long-term effects induced by rapid maxillary expansion (RME) on the shape of the maxillary and circummaxillary structures by means of thin-plate spline (TPS) analysis. The sample consisted of 42 patients who were compared with a control sample of 20 subjects. The treated subjects underwent Haas-type RME, followed by fixed appliance therapy. Postero-anterior (PA) cephalograms were analysed for each treated subject at T1 (pre-treatment), T2 (immediate post-expansion), and T3 (long-term observation), and were available at T1 and T3 for the control group (CG). The mean age at T1 was 11 years and 10 months for both groups. The mean chronological ages at T3 were 20 years, 6 months for the treated group (TG) and 17 years, 8 months for the control group. The study focused on shape changes in the maxillary, nasal, zygomatic, and orbital regions. TPS analysis revealed significant shape changes in the TG. They consisted of an upward and lateral displacement of the two halves of the naso-maxillary complex as a result of active expansion in the short-term, and normalization of maxillary shape in the transverse dimension in the long-term (the initial transverse deficiency of the maxilla in the treated group was eliminated by RME therapy both in the short- and long-term). At the end of the observation period, the nasal cavities were larger when compared with both their pre-expansion configuration and the final configuration in the controls. RME with the Haas appliance appears to be an efficient therapeutic means to induce permanent favourable changes in the shape of the naso-maxillary complex.

PMID: 12001550 [PubMed - indexed for MEDLINE]

Optident prize 2000.

J Orthod. 2002 Mar;29(1):3-13

Authors: McKeown HF

This paper describes the orthodontic treatment of two cases, which were awarded the 2000 Optident prize.

PMID: 11907304 [PubMed - indexed for MEDLINE]

Skeletal and dento-alveolar stability after surgical-orthodontic treatment of anterior open bite: a retrospective study.

Eur J Orthod. 2001 Oct;23(5):547-57

Authors: Swinnen K, Politis C, Willems G, De Bruyne I, Fieuws S, Heidbuchel K, van Erum R, Verdonck A, Carels C

The aim of this investigation was to assess skeletal and dento-alveolar stability after surgical-orthodontic correction of skeletal anterior open bite treated by maxillary intrusion (group A) versus extrusion (group B). The cephalometric records of 49 adult anterior open bite patients (group A: n = 38, group B: n = 11), treated by the same maxillofacial surgeon, were examined at different timepoints, i.e. at the start of the orthodontic treatment (T1), before surgery (T2), immediately after surgery (T3), early post-operatively (+/- 20 weeks, T4) and one year post-operatively (T5). A bimaxillary operation was performed in 31 of the patients in group A and in six in group B. Rigid internal fixation was standard. If maxillary expansion was necessary, surgically assisted rapid palatal expansion (SRPE) was performed at least 9 months before the Le Fort I osteotomy. Forty-five patients received combined surgical and orthodontic treatment. The surgical open bite reduction (A, mean 3.9 mm; B, mean 7.7 mm) and the increase of overbite (A, mean 2.4 mm; B, mean 2.7 mm), remained stable one year post-operatively. SNA (T2-T3), showed a high tendency for relapse. The clockwise rotation of the palatal plane (1.7 degrees; T2-T3), relapsed completely within the first post-operative year. Anterior facial height reduction (A, mean -5.5 mm; B, mean -0.8 mm) occurred at the time of surgery. It can be concluded that open bite patients, treated by posterior Le Fort I impaction as well as with anterior extrusion, with or without an additional bilateral sagittal split osteotomy (BSSO), one year post-surgery, exhibit relatively good clinical dental and skeletal stability.

PMID: 11668874 [PubMed - indexed for MEDLINE]

Rapid palatal expansion in mixed dentition using a modified expander: a cephalometric investigation.

J Orthod. 2001 Jun;28(2):129-34

Authors: Cozza P, Giancotti A, Petrosino A

The aims of this investigation were to cephalometrically study the short-term skeletal and dental modifications induced by rapid palatal expansion in a sample of 20 patients (10 male, 10 female), aged 6-10 years (mean age 8 years) in mixed dentition with a uni- or bilateral posterior crossbite, a mild skeletal Class II malocclusion, and an increased vertical dimension (FMA, SN/\GoGn), and to compare them with an untreated matched control group of 20 subjects (10 male and 10 female), mean age 8 years. Cephalometric analysis showed that the maxilla displayed a tendency to rotate downwards and backward, resulting in a statistically significant increase of the SN/\PP angle (T0 = 9*95 degrees, T1 = 11*60 degrees, P < 0*01) and the SN-ANS linear value (T0 = 49*50 mm, T1 = 51*10 mm, P < 0*05). In addition, there was a statistically significant alteration of the anterior total facial height N-Me (T0 = 113*15mm, T1 = 114*15 mm, P < 0*05) and for the dental upper molar measurement U6-PP (T0 = 19*70 mm, T1 = 20*30 mm, P < 0*05). The small alterations found in the anterior total facial height and in the sagittal angles agree with previous studies, and suggest that RPE can be also used in subjects with a tendency to vertical growth and a skeletal Class II malocclusion.

PMID: 11395527 [PubMed - indexed for MEDLINE]

Mandibular advancement using an intra-oral osteogenic distraction technique: a report of three clinical cases.

J Orthod. 2001 Jun;28(2):105-14

Authors: Mattick CR, Chadwick SM, Morton ME

Osteogenic distraction has been used for decades to lengthen limbs and now attention is focused upon its use within the craniofacial skeleton. This paper addresses distraction of the mandible. It is proposed that mandibular osteogenic distraction could be a possible adjunct to the orthodontic treatment of those adult patients with skeletal anomalies, who would benefit from combined orthodontic/orthognathic treatment. Three consecutive cases from one unit are presented, where adult patients with severe Class II division 1 malocclusions have undergone orthodontic treatment combined with mandibular osteogenic distraction, instead of conventional bilateral sagittal split osteotomies.

PMID: 11395524 [PubMed - indexed for MEDLINE]

Effect of rapid maxillary expansion on skeletal, dental, and nasal structures: a postero-anterior cephalometric study.

Eur J Orthod. 2000 Oct;22(5):519-28

Authors: Cross DL, McDonald JP

The purpose of this study was to compare the transverse dimensions of skeletal, dental, and nasal structures of a group of patients with maxillary narrowness before and after rapid maxillary expansion (RME) with an untreated control group using postero-anterior (PA) cephalometric radiographs. The material consisted of PA cephalograms of 25 children with a posterior crossbite (mean age 13 years 4 months), and 25 age- and sex-matched controls (mean age 13 years 11 months). Both groups consisted of 20 females and five males. Thirty-four reference points were digitized using the Dentofacial Planner software program. The 17 variables studied consisted of six skeletal, four dental, and seven intra-nasal linear measurements. Student's t-tests were used to compare the differences between the groups, and the effect of RME on skeletal, dental, and nasal structures. RME produced small, but statistically significant changes in maxillary width, upper and lower molar widths, the width between upper central incisor apices, and intra-nasal width. When compared with previous studies, the changes observed were similar for patients of a similar age group, but less than reported for a younger population. There is some evidence that the pattern of expansion produced by RME will vary depending on the age and maturity of the subject.

PMID: 11105408 [PubMed - indexed for MEDLINE]

The B.S.S.O. M.Orth. Prize of the Royal College of Surgeons of England 1998.

J Orthod. 2000 Dec;27(4):287-94

Authors: Patel S

PMID: 11099565 [PubMed - indexed for MEDLINE]

The William Houston Gold Medal 1998.

J Orthod. 2000 Jun;27(2):119-25

Authors: Mullane C

PMID: 10867067 [PubMed - indexed for MEDLINE]

How much space is created from expansion or premolar extraction?

J Orthod. 2000 Mar;27(1):11-3

Authors: O'Higgins EA, Lee RT

The aim of this study was first to investigate the relationship between maxillary arch expansion and change in arch depth (overjet), and secondly to quantify the reduction in maxillary arch depth following extraction of 4\4 with complete space closure. A model of maxillary typodont teeth was constructed to allow expansion and premolar removal. Arch dimensions were recorded using a reflex microscope. A linear relationship was found between arch expansion and reduction of the arch depth. When the premolars were removed, there was a greater reduction in arch depth than the mesio-distal width of these teeth.

PMID: 10790440 [PubMed - indexed for MEDLINE]

The Gold Medal Prize in the Conjoint M.Orth. exam of the Royal College of Surgeons of Edinburgh held in Hong Kong, 1996.

J Orthod. 2000 Mar;27(1):1-10

Authors: Foong KW

PMID: 10790439 [PubMed - indexed for MEDLINE]

Rapid palatal expansion in treatment of Class II malocclusions.

Br J Orthod. 1999 Sep;26(3):179-90

Authors: Giancotti A, Maselli A, Di Girolamo R

A technique which combines the use of rapid maxillary expansion and fixed appliance in growing patients, is presented. The treatment in three patients with Class II division 1 malocclusion and different skeletal patterns is described, and relative advantages highlighted.

PMID: 10532156 [PubMed - indexed for MEDLINE]

Force-induced rapid changes in cell fate at midpalatal suture cartilage of growing rats.

J Dent Res. 1999 Sep;78(9):1495-504

Authors: Kobayashi ET, Hashimoto F, Kobayashi Y, Sakai E, Miyazaki Y, Kamiya T, Kobayashi K, Kato Y, Sakai H

The application of expansional force induces replacement of the cartilaginous tissue with bone at the midpalatal suture of growing rats. We examined the early cellular events evoked by force by analyzing the expression of proliferating cell nuclear antigen (PCNA), an operational marker of cell proliferation, and of several bone matrix proteins. A rectangular orthodontic appliance was set between the right and left upper molars of four-week-old rats, with 50 g of initial expansional force. Two days after application of the force, the pre-existing cartilage was separated laterally. Mesenchymal cells with stretched shapes were arranged parallel to the expansional force and filled the center of the suture. Only a few of these stretched cells exhibited nuclear accumulation of PCNA. In contrast, many polygonal mesenchymal cells distributed along the inner lateral side of the cartilaginous tissue exhibited strong immunoreactivity for PCNA. Localization of alkaline phosphatase activity overlapped into this proliferating cell zone. Nascent extracellular matrix under the proliferating cells was positive for osteocalcin, indicating commencement of active bone formation. These findings indicated that, among mesenchymal cells subjected to expansional forces, only cells located on the inner side of the cartilaginous tissue proliferate and differentiate into osteoblasts. In agreement with rapid bone growth progression, apoptosis was also observed in the zone of proliferating cells, as measured by TdT-mediated dUTP-biotin nick end labeling (TUNEL) assays.

PMID: 10512383 [PubMed - indexed for MEDLINE]

Management of space problems in the primary and mixed dentitions.

J Am Dent Assoc. 1999 Sep;130(9):1330-9

Authors: Ngan P, Alkire RG, Fields H

BACKGROUND: According to the Third National Health and Nutrition Examination Survey, crowding and irregularity remain a consistent problem for children. Management of space problems continues to play an important role in a dental practice. It also represents an area of major interaction between the primary provider and the specialists. This article attempts to update clinicians on the current knowledge of space management. DESCRIPTION OF CONDITION: Proper management of space in the primary and mixed dentitions can prevent unnecessary loss in arch length. Diagnosing and treating space problems requires an understanding of the etiology of crowding and the development of the dentition to render treatment for the mild, moderate and severe crowding cases. Most crowding problems with less than 4.5 millimeters can be resolved through preservation of the leeway space, regaining space or limited expansion in the late mixed dentition. In cases with 5 to 9 mm of crowding, some can be approached with expansion after thorough diagnosis and treatment planning. Most of these cases will require extraction of permanent teeth to preserve facial esthetics and the integrity of the supporting soft tissue. Serial extraction or guidance of eruption is reserved for treatment of severe tooth-size/arch-size discrepancies. Due to variations in the timing and extraction sequence depending on the diagnosis, serial extraction should be reserved for those who can complete the treatment successfully. CLINICAL IMPLICATIONS: The recommended timing of referring patients with moderate crowding to specialists for treatment is in the late mixed-dentition stage of development. Patients with severe crowding will require earlier evaluation for serial extraction.

PMID: 10492540 [PubMed - indexed for MEDLINE]