Facemask therapy with miniplate implant anchorage in a patient with maxillary hypoplasia.

Chin Med J (Engl). 2007 Aug 5;120(15):1372-5

Authors: Zhou YH, Ding P, Lin Y, Qiu LX

PMID: 17711747 [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]

Treatment effects of occipitomental anchorage appliance of maxillary protraction combined with chincup traction in children with Class III malocclusion.

J Formos Med Assoc. 2007 May;106(5):380-91

Authors: Lin HC, Chang HP, Chang HF

BACKGROUND/PURPOSE: Little information related to the treatment effects of the occipitomental anchorage (OMA) appliance of maxillary (Mx) protraction combined with chincup traction is available. The aim of this study was to investigate the treatment effects of the OMA orthopedic appliance on patients with Class III malocclusion. METHODS: Pretreatment and post-treatment cephalometric records of 20 consecutively treated patients with Class III malocclusions were evaluated and compared with a matched sample of untreated Class III control subjects. RESULTS: The OMA appliance is effective for correcting skeletal Class III malocclusion in growing children. The treatment effects of this orthopedic appliance were considered to be from both skeletal and dentoalveolar changes. The skeletal effects were mainly obtained by stimulating forward growth of the Mx complex with negligible rotation of the Mx plane and restraining forward advancement of the mandible (Mn) with backward and downward rotation of the Mn plane. The observed dentoalveolar effects were mostly due to the labial tipping movement of the Mx incisors. CONCLUSION: Our results suggest that the OMA orthopedic appliance can correct the mesial jaw relationship and negative incisal over jet. This appliance is effective for correcting skeletal Class III malocclusion with both midface deficiency and Mn prognathism in growing children.

PMID: 17561473 [PubMed - indexed for MEDLINE]

Effects of activator and high-pull headgear combination therapy: skeletal, dentoalveolar, and soft tissue profile changes.

Eur J Orthod. 2007 Apr;29(2):140-8

Authors: Marşan G

The aim of this study was to evaluate skeletal, dentoalveolar, and soft tissue profile changes with activator and high-pull headgear combination therapy in patients with Class II malocclusions caused by maxillary prognathism and mandibular retrognathism. The subjects, all in the mixed dentition, were selected from a single centre and were divided into two groups: 28 patients were treated with an incisor double capping activator and a high-pull headgear combination appliance (13 girls, 15 boys mean chronological age 11.7 +/- 1.2 years, skeletal age 12.1 +/- 1.4 years) and an untreated group of 28 subjects (14 girls, 14 boys mean chronological mean age 11.9 +/- 1.1 years, skeletal age 12.3 +/- 1.3 years). The skeletal, dentoalveolar, and soft tissue profile changes that occurred were compared on lateral cephalograms taken before treatment (T0) and after 1.1 +/- 0.3 years when the combination appliance was removed (T1). In the control group, the radiographs were obtained at the start (T0) and after an observation period 1.2 +/- 0.4 years (T1). Statistical analysis was undertaken with Wilcoxon's ranked-sum test for intra-group comparisons and differences between groups with t-test and Bonferroni's test at a level of significance of P < 0.05. Activator and high-pull headgear combination treatment in these growing patients resulted in a correction of the skeletal Class II relationship (ANB -3.4 degrees), a restriction of maxillary growth (SNA -2.0 degrees, OLp-A -2.3 mm), an advancement of the mandibular structures (SNB +2.6 degrees, FH-NPg +2.3 degrees, OLp-B +2.7 mm, OLp-Pg +2.2 mm), an increase in lower face height (ANS-Me +3.9 mm), a correction of the overjet (-5.4 mm), an improvement in overbite (-2.2 mm), uprighting of the maxillary incisors (U1-FH -5.3 degrees, OLp-U1 -2.5 mm), protrusion of the mandibular incisors (IMPA +2.0 degrees, OLp-L1 +2.7 mm), and a correction of the dental Class II malocclusion (OLp-L6 +3.5 mm). The soft tissue profile changes were a correction of facial convexity (G'-Sn-Pg' angle 2.3 degrees, Mlf-Li-x-axis angle 9.1 degrees), and an increase in lower antero-posterior (Mlf-y-axis 5.6 mm, Pg'-y-axis 5.3 mm), and lower vertical (Sls-x-axis 3.8 mm, Pg'-x-axis 3.8 mm, Me'-x-axis 5.1 mm) soft tissue dimensions. The mentolabial fold depth (Mlf-E line) also significantly decreased, -0.8 mm in the treated group. The activator and high-pull headgear combination appliance was effective in treating growing patients with maxillary prognathism, mandibular deficiency, and facial convexity by a combination of skeletal and dentoalveolar changes and improvement in the soft tissue facial profile.

PMID: 17488997 [PubMed - indexed for MEDLINE]

Comparison of the headgear activator and Herbst appliance--effects and post-treatment changes.

Eur J Orthod. 2006 Dec;28(6):594-604

Authors: Phan KL, Bendeus M, H&#xE4;gg U, Hansen K, Rabie AB

The aim of this study was to evaluate the effects of the headgear activator (HGA) and Herbst appliance during active treatment and retention and at follow-up in children with a skeletal Class II malocclusion. The two groups comprised 16 consecutive male patients (mean age 11.6 +/- 1.42 years) treated with a HGA and 16 male patients (mean age 12.6 +/- 1.13 years) treated with a Herbst appliance and Andresen activator (HAA) sampled from a larger pool using similar selection criteria. Growth data were obtained for the two groups. Lateral cephalograms taken at the start, after 6 months of treatment, after 12 months of active treatment or 6 months of retention, and at the 24-month follow-up were analysed. The total changes over the whole observation period (T0-T3) did not differ significantly between the groups; there was, however, a statistically significant increase in jaw prognathism (P < 0.05) and improvement of the molar relationship (P < 0.05) in the HAA group as compared with the HGA group. During the initial treatment phase (T0-T1), the overall treatment effects were statistically more pronounced in the HAA group than in the HGA group. Despite significant differences in treatment effects and changes between the two devices, there were no significant overall changes at follow-up except for the prognathism, i.e. maxillary prognathism decreased with treatment with the HGA while mandibulars prognathism continued to increase with HAA treatment.

PMID: 17142260 [PubMed - indexed for MEDLINE]

Anterior open bite treated with a palatal crib and high-pull chin cup therapy. A prospective randomized study.

Eur J Orthod. 2006 Dec;28(6):610-7

Authors: Torres F, Almeida RR, de Almeida MR, Almeida-Pedrin RR, Pedrin F, Henriques JF

The aim of this prospective randomized clinical study was to cephalometrically investigate the dentoalveolar and soft tissue changes produced by a removable appliance with a palatal crib associated with high-pull chin cup therapy in children with an Angle Class I anterior open bite (AOB) malocclusion. Thirty children (8 males and 22 females) with an initial mean age of 8.3 years and a mean AOB of 4.1 mm were treated with a removable appliance composed of a palatal crib associated with chin cup therapy for 12 months. A control group of 30 individuals (7 males and 23 females) closely matched for age, initial mean age 8.6 years, gender, and ethnicity with a mean AOB of 4.6 mm was followed without treatment. The measurements (means and standard deviations) were statistically analysed using a paired t-test. The results showed no significant differences in the level of molar eruption or in lower anterior face height, suggesting that the vertical control expected from the chin cup therapy did not occur. Dentoalveolar changes at the anterior region were evident, with statistically significant extrusion, retrusion, and lingual tipping of the maxillary and mandibular incisors (P < or = 0.05). However, these hard tissue changes did not imply soft tissue changes and the variables related to the soft profile were not statistically significantly different between the groups. The dentoalveolar changes at the anterior region of the dental arches were mainly responsible for closure of the AOB in patients treated in the mixed dentition.

PMID: 17101701 [PubMed - indexed for MEDLINE]

Changes in orthodontic cephalometric reference points on application of orthopedic force to jaw: three-dimensional finite element analysis.

Bull Tokyo Dent Coll. 2005 Aug;46(3):59-65

Authors: Katada H, Katada H, Isshiki Y

The present study investigated the effects of two orthodontic appliances on changes in the cephalometric reference planes using the three-dimensional finite element method. We simulated the use of a headgear and an orthopedic facial mask, two devices for the application of orthodontic force to the jaw. Using a finite element model of the skull, orthodontic force was applied to the maxillary first molar in a posterior or anterior direction. Changes in the maxilla, mandible and cephalometric reference planes were ascertained by the three-dimensional finite element method. The results showed that posterior force caused a slight posterior displacement and clockwise rotation of the reference planes, while anterior force caused anterior displacement and counterclockwise rotation. Since the maxilla was displaced and rotated in the same direction, the degrees of cephalometric displacement and rotation of the maxilla were smaller than the actual values.

PMID: 16598182 [PubMed - indexed for MEDLINE]

Thin-plate spline analysis of the effects of face mask treatment in children with maxillary retrognathism.

J Formos Med Assoc. 2006 Feb;105(2):147-54

Authors: Chang JZ, Liu PH, Chen YJ, Yao JC, Chang HP, Chang CH, Chang FH

BACKGROUND: Face mask therapy is indicated for growing patients who suffer from maxillary retrognathia. Most previous studies used conventional cephalometric analysis to evaluate the effects of face mask treatment. Cephalometric analysis has been shown to be insufficient for complex craniofacial configurations. The purpose of this study was to investigate changes in the craniofacial structure of children with maxillary retrognathism following face mask treatment by means of thin-plate spline analysis. METHODS: Thirty children with skeletal Class III malocclusions who had been treated with face masks were compared with a group of 30 untreated gender-matched, age-matched, observation period-matched, and craniofacial configuration-matched subjects. Average geometries, scaled to an equivalent size, were generated by means of Procrustes analysis. Thin-plate spline analysis was then performed for localization of the shape changes. RESULTS: Face mask treatment induced a forward displacement of the maxilla, a counterclockwise rotation of the palatal plane, a horizontal compression of the anterior border of the symphysis and the condylar region, and a downward deformation of the menton. The cranial base exhibited a counterclockwise deformation as a whole. CONCLUSION: We conclude that thin-plate spline analysis is a valuable supplement to conventional cephalometric analysis.

PMID: 16477335 [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]

Prediction of post-treatment outcome after combined treatment with maxillary protraction and chincap appliances.

Eur J Orthod. 2006 Feb;28(1):89-96

Authors: Yoshida I, Yamaguchi N, Mizoguchi I

The aims of this study were to identify differences in the initial skeletal morphology between successful and unsuccessful groups and to establish a novel method for predicting the final outcome of treatment with a maxillary protraction appliance (MPA) and chincap. The cephalograms used in this study were taken from 32 Japanese girls (mean age 10.2 years) with a Class III malocclusion at the beginning of treatment with an MPA and chincap (T1), at removal of the appliance (T2), and during the final post-treatment period (T3). The subjects were divided into two groups according to the treatment outcome at T3. Lower face height (ANS-Me), total face height (N-Me), ratio of face height (ANS-Me/N-ANS), maxillary position, mandibular plane and gonial angle at T1 were all significantly larger in the unsuccessful group, compared with the successful group. Discriminant analysis indicated that lower face height and gonial angle were significant determinants for distinguishing between the two groups at T1. From T1 to T2, while the anterior displacement of the maxilla was almost the same in the two groups, SNB decreased by 1.6 degrees in the successful group and 0.4 degrees in the unsuccessful group. After orthopaedic treatment, a second phase of treatment with a multibracket system was performed (T2 to T3). From T2 to T3, SNA increased by 0.4 degrees in the successful group and decreased by 0.7 degrees in the unsuccessful group. These results indicate that the vertical dimensions of the craniofacial skeleton are important for predicting the prognosis of skeletal Class III patients treated with a MPA and chincap and that the discriminant formula established in this study is effective in predicting the final treatment outcome.

PMID: 16113036 [PubMed - indexed for MEDLINE]

Effect of cervical headgear wear on dynamic measurement of head position.

Eur J Orthod. 2005 Oct;27(5):437-42

Authors: Usumez S, Orhan M, Uysal T

The aim of this study was to identify the effect of cervical headgear (CHG) wear on dynamic measurement of head posture during walking. Six male and 10 female patients (mean age, 11.9 +/- 1.9 years) who were receiving CHG therapy for correction of a Class II molar relationship as part of their orthodontic treatment were included in this study. Dynamic head posture measurements were recorded using an inclinometer and data logger apparatus during a walking session of 5 minutes. This procedure was repeated before (T1) and after (T2) insertion of CHG. The T1 and T2 measurements were repeated twice at 30-minute intervals. The mean dynamic head posture was calculated for each subject using the collected data. The means of these measurements were statistically compared using a paired t-test. Of the 16 subjects, 14 showed a cranial flexion with CHG wear in relation to T1 (1.4 to 8.9 degrees). The other two subjects showed a cranial extension of -1.6 and -3.8 degrees. The mean values at T1, T2 and T1-T2 were 1.4, -1.8, and 3.1 degrees, respectively, which indicated a mean cranial flexion at T2 in relation to T1. According to the paired sample t-test, there were statistically significant differences between the two measurements of dynamic head posture recorded before and after CHG insertion (P < 0.001). CHG wear causes a significant cranial flexion which may be responsible for its effects on the mandible.

PMID: 16093258 [PubMed - indexed for MEDLINE]

Effects of activator and activator headgear treatment: comparison with untreated Class II subjects.

Eur J Orthod. 2006 Feb;28(1):27-34

Authors: T&#xFC;rkkahraman H, Sayin MO

The aims of this study were to determine whether the activator and activator headgear encourage mandibular growth, and whether there is any superiority of one appliance over the other or if the resultant changes are due to normal growth. Forty-nine skeletal Class II division 1 patients were selected. Thirty-three (13 females, 20 males; mean age 12.52 +/- 1.42 years) were treated with an Andresen activator and the remaining 16 (7 females, 9 males; mean age 13.04 +/- 1.47 years) with an activator headgear combination. Twenty Class II subjects (9 females, 11 males; mean age 12.57 +/- 1.11 years) who had previously refused treatment served as a control group. Cephalometric landmarks were marked and digitized by one author to avoid inter-observer variability. Nine angular and 12 linear measurements were established and measured using Vistadent AT software. A paired-sample t-test and an ANOVA test were used to statistically evaluate the findings. The results revealed that both the activator and the activator headgear combination significantly (P < 0.001) encouraged mandibular growth, but had little restraining effect on the maxilla. The mandibular incisors were more controlled in the activator headgear combination group. The resultant skeletal, dentoalveolar and soft tissue changes differed significantly from those due to growth.

PMID: 16093256 [PubMed - indexed for MEDLINE]

The effects of early headgear treatment on dental arches and craniofacial morphology: an 8 year report of a randomized study.

Eur J Orthod. 2005 Oct;27(5):429-36

Authors: Pirttiniemi P, Kantomaa T, Mäntysaari R, Pykäläinen A, Krusinskiene V, Laitala T, Karikko J

The aim of this study was to determine the long-term effects of early headgear (HG) treatment on craniofacial structures. The total study group comprised 68 children (40 males and 28 females) aged 7.6 years (standard deviation 0.3 years). The children, who had a Class II tendency in occlusion and moderate crowding, were randomly divided into two groups of equal size. In the first group, HG treatment was initiated immediately. In the second group, which served as a control group, only minor interceptive procedures were performed during the first follow-up period of 2 years. During the 8 year follow-up, orthodontic therapy, including fixed appliances and possible extractions, was carried out when necessary. The results showed that the most evident difference between the groups was the wider and longer dental arches in the HG group, which could only partly be explained by the higher rate of extractions in the control group. For the cephalometric measurements, the most significant difference was in the maxillary plane orientation. The peer assessment rating (PAR) score, showing the general outcome of treatment, was at the same level in both groups at follow-up. The deficit of the early HG treatment was the longer mean total treatment time, resulting from the two-phase treatment.

PMID: 15961567 [PubMed - indexed for MEDLINE]

The role of psycho-social factors in headgear compliance.

Eur J Orthod. 2005 Jun;27(3):263-7

Authors: Ağar U, Doruk C, Biçakçi AA, Büküsoğlu N

The aim of this study was to identify the role of psycho-social factors in headgear compliance. Fifty-one patients, with an Angle Class II division 1 malocclusion comprised the study sample. The treatment plan aimed to correct the malocclusion using cervical pull headgear. An electronic module timer was attached to the neckstrap to evaluate the number of hours the patients wore the headgear. One of their parents was asked to answer the Child Behaviour Checklist (CBCL), which defines a patient's behaviour. The patients were monitored for 6 months and the modules were measured at the end of each 2 month period. Mann-Whitney U and Chi square tests were used to analyse the data. The patients were separated into groups according to their compliance.The results showed that although there were significant differences in the use of headgear between the groups (P < or = 0.001), age, gender, and CBCL subgroup scores were not statistically significant (P > 0.05).

PMID: 15947226 [PubMed - indexed for MEDLINE]

Maurice Berman Prize 2003.

J Orthod. 2004 Dec;31(4):279-87

Authors: McKeown HF

A crowded, high angle Class II case is presented and illustrated with stage clinical photographs. It was successfully treated with modified Twin Blocks and high pull headgear, extraction of all four first premolars, and upper and lower pre-adjusted edgewise appliances.

PMID: 15608342 [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]

The role of the headgear timer in extraoral co-operation.

Eur J Orthod. 2004 Jun;26(3):289-91

Authors: Doruk C, A&#x11F;ar U, Babacan H

The aim of this research was to study headgear co-operation using an objective measuring instrument, the Compliance Science System (CSS). Forty-six patients were included in the investigation, 32 girls and 14 boys (10-15 years of age; mean 13 years). The patients, who were not informed that they were being monitored, were instructed to wear the headgear, with an electronic module timer attached to the neckstrap, for 16 hours per day. At the end of 2 months (T1), the time for which the headgear was worn was measured. At this stage the patients were divided into two groups: group 1 (unco-operative patients) who wore the headgear for less than 16 hours per day, and group 2 (co-operative patients) who wore the headgear for at least 16 hours per day. Only the unco-operative patients were informed that they had been monitored, and a subsequent 4 month treatment period was initiated for both groups. The time was also measured at the end of the second (T2) and third (T3) 2 month treatment periods. The unco-operative patients increased their use of the headgear to approximately 4.5 to 6 hours per day (P < 0.05). All of the co-operative patients also used their headgear as recommended during the 4 month period.

PMID: 15222714 [PubMed - indexed for MEDLINE]

An orthopaedic approach to the treatment of Class III malocclusions in the early mixed dentition.

Eur J Orthod. 2004 Apr;26(2):191-9

Authors: Cozza P, Marino A, Mucedero M

The aim of this investigation was to study cephalometrically the skeletal, dental and soft tissue modifications induced by a Delaire facemask and Bionator III appliance in a sample of 30 patients (17 boys and 13 girls), aged 4.1-9 years [mean 5.85 years, confidence interval (CI) 5.41-6.29], in the early mixed dentition with a skeletal Class III malocclusion caused by maxillary retrognathism (group 1) and compared with a control sample of 24 subjects (14 boys and 10 girls), aged 4-9 years (mean 5.97 years, CI 5.35-6.58) with untreated Class III malocclusions (group 2). For each patient a lateral cephalogram was taken before treatment (T0), after facemask removal (T1), and at the end of the retention period with a Bionator III (T2). Cephalometric analysis was carried out. The post-treatment cephalometric values in the treated group showed a forward displacement of the maxilla resulting in a statistically significant increase (P < 0.001) in the SNA angle, A-NPg (mm) and PNS-A (mm) linear values. There was a clockwise rotation of the mandible, with a decrease in the SNB angle and a satisfactory correction of the Class III relationship. The beneficial effects on the facial profile were confirmed by an increase in UL-EL distance and in NB--HL and NsPgs--HL angles, and by a decrease in the facial convexity angle. These findings indicate that the Delaire facemask and Bionator III treatment is effective for correcting skeletal Class III malocclusions caused by maxillary retrognathism in the early mixed dentition.

PMID: 15130043 [PubMed - indexed for MEDLINE]

The effects of early headgear treatment on dental arches and craniofacial morphology: a report of a 2 year randomized study.

Eur J Orthod. 2004 Feb;26(1):59-64

Authors: M&#xE4;ntysaari R, Kantomaa T, Pirttiniemi P, Pykäläinen A

The aim of the present study was to determine the effects of early headgear treatment on dental arches and craniofacial morphology in children in the early mixed dentition. The total study group comprised 68 children of both sexes (40 boys and 28 girls) aged 7.6 years [standard deviation (SD) 0.3]. The children, who had a Class II tendency in occlusion and moderate crowding of the dental arches, were randomly divided into two groups of equal size, matched according to gender. In the headgear (HG) group, treatment was initiated immediately. The mean treatment time was 16 months. In the second group, which served as the control, only interceptive procedures were performed during the follow-up period. The records, which included dental casts and lateral cephalograms, were obtained after follow-up periods of 1 and 2 years. The lengths and the widths of the maxillary and mandibular dental arches were significantly increased in the HG group after the 2 year follow-up period. The mean increase in lower arch length and width was 2.4 mm (SD 1.7) and 2.2 mm (SD 1.2), respectively. On average, the space gain in the lower arch was half that of the upper arch. No significant changes were found in the arch dimensions of the control group. Maxillary growth restraint and labial tilting of the incisors were the most significant cephalometric findings in the HG group when compared with the controls. The use of headgear in the early mixed dentition is effective in the treatment of moderate crowding. It is noteworthy that significant space gain in the dimensions of the lower arch can be achieved by headgear application to the upper first molars.

PMID: 14994883 [PubMed - indexed for MEDLINE]

The effect of a modified reverse headgear force applied with a facebow on the dentofacial structures.

Eur J Orthod. 2004 Feb;26(1):51-7

Authors: Göyenç Y, Ersoy S

The purpose of this study was to evaluate the effects of a modified reverse headgear force applied with a facebow on the dentofacial structures of patients with skeletal Class III malocclusions characterized by maxillary retrognathism. Thirty individuals before the pubertal peak and in the mixed dentition were selected. Fifteen subjects (seven males, eight females, mean age 9.2 years) who formed the treatment group were compared with a control group comprising seven males and eight females (mean age 8.6 years). Maxillary deficiency and negative overjet were noted in all individuals included in the treatment and control groups. The combination of a full coverage maxillary removable appliance and an embedded facebow was used for treatment. The outer arms of the facebow were bent to deliver the force through the approximate centre of resistance of the maxilla. Extra-oral elastics extended from the reverse headgear to the outer arms of the facebow. Statistical analysis indicated significant changes in angles SNA, NV-A, SV-ANS, SV-PNS and PP measurements, suggesting that the maxilla moved anteriorly. There was, however, no statistically significant difference in SN-MP, SN-PP and MP-PP measurements between the treatment and control groups. These results suggest that there was no maxillary or mandibular rotation, but that the molars moved mesially in the protraction group. The U6-PP(V) dimension did not display significant differences between the pre- and post-treatment measurements in the treated group. Anterior movement of the maxilla was obtained without rotation of the jaws and upper and lower maxillary heights were unaffected.

PMID: 14994882 [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]

Long-term effects of chin-cap therapy on the temporomandibular joints.

Eur J Orthod. 2003 Oct;25(5):471-5

Authors: Arat ZM, Ak&#xE7;am MO, Gökalp H

It is commonly believed that upward/backward forces applied to the condyle by a chin-cap cause temporomandibular dysfunction (TMD). In the current study the long-term follow-up (2-11 years) of patients treated with a chin-cap was investigated regarding signs and symptoms of TMD. The treatment group consisted of 32 individuals who had a skeletal Class III malocclusion treated using chin-cap therapy (mean age 18.4 years). The two control groups contained 39 untreated subjects with skeletal Class III malocclusions (mean age 15.5 years) and 53 dental students (mean age 19.2 years) with acceptable normal occlusions. Functional examination of the subjects was carried out and those with at least one sign/symptom (clicking, pain, or deviation) were identified as the 'symptomatic' subgroup. The distribution of symptomatic individuals was 25 per cent in the treatment group, 23 per cent in the Class III malocclusion group, and 41.5 per cent in the normal group (dental students). In addition, the frequency of signs and symptoms of TMD in the symptomatic individuals was also investigated. There were no signs of crepitus in any subject, clicking was found in 50 per cent of the treatment group and pain in 54.5 per cent of the normal group. The results of this long-term follow-up indicate that chin-cap treatment is neither a risk factor nor a prevention for TMD. Age and stress factors should always be considered in the evaluation of TMD.

PMID: 14609015 [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]

Social inequality and discontinuation of orthodontic treatment: is there a link?

Eur J Orthod. 2003 Apr;25(2):175-83

Authors: Turbill EA, Richmond S, Wright JL

The aims of this study were to investigate the effects of social inequality on the likelihood of patients discontinuing orthodontic treatment, and to determine which, if any, indicators of social inequality are of greater relevance. In this retrospective study of English and Welsh General Dental Services (GDS) cases, consecutive 'discontinued' cases collected at the Dental Practice Board (DPB) during 1990-91, were compared for age, treatment modality, and measures of social inequality, with a 2 per cent sample of cases contemporaneously submitted as 'complete'. Three deprivation indices, and occupation-based social class spectra of neighbourhoods, were compared between the groups. A model was sought to predict discontinuation/completion using logistic regression analysis. The discontinued sample represented lower social stratum spectra for home and practice areas under all indicators tested, and the subjects were a little older at the start of treatment. Fewer were treated by orthodontically qualified practitioners or with fixed appliances, but more with extra-oral traction. Occupation-based classification (patient's home) and the Carstairs Index (practice area) were selected by the analysis as explaining more of the variation than other measures of social inequality, but the model failed to predict the discontinued cases. Lower social class may be a risk factor for discontinuation of orthodontic treament, but is not a predictor for it. Patients should be considered for, and counselled about, orthodontic treatment on an individual basis. Occupation-based social classifications and the Carstairs Index may be a little more sensitive to orthodontic applications than other indicators of social inequality.

PMID: 12737216 [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]

Orthopedic cervical headgear in class II treatment: case report.

Braz Dent J. 2003;14(1):63-6

Authors: Enoki C, Matsumoto MA, Ferreira JT

Early treatment for Class II malocclusion was undertaken with the objective of correcting skeletal disproportion by altering the growth pattern. A case of Class II, Division 1 malocclusion in the mixed dentition was corrected to Class I molar relationship using orthopedic cervical headgear, with nonextraction edgewise therapy. Cephalometric analysis indicated a reduction in the maxillomandibular discrepancy (ANB) correcting the Class II malocclusion to Class I malocclusion. The treatment showed that this was achieved by downward displacement and inhibition of the forward growth of the maxilla and growth of the mandible. There was no downward rotation of the mandible nor maxillary first molar extrusion. There was improvement in the jaw relationship.

PMID: 12656468 [PubMed - indexed for MEDLINE]

Long-term follow-up of early treatment with reverse headgear.

Eur J Orthod. 2003 Feb;25(1):95-102

Authors: H&#xE4;gg U, Tse A, Bendeus M, Rabie AB

The purpose of this study was to investigate the long-term outcome of treatment with reverse headgear in young individuals with a reverse overjet and a skeletal Class III malocclusion due to maxillary deficiency. Lateral cephalograms were obtained from 21 subjects (8.4 +/- 1.5 years; 17 girls and four boys) of an original sample of 30 consecutively treated young patients who were followed for 8 years after active treatment. There was a drop-out of nine subjects; their dentofacial morphology at start of treatment did not differ from those who remained in the study. The remaining subjects were divided into a stable group and a relapse group. The results revealed that two out of three patients maintained a positive overjet 8 years after active treatment. The immediate treatment outcome in the sagittal plane was the same for the stable and relapse groups, but lower face height increased (P < 0.08) and the mandibular plane angle opened (P < 0.05) more in the relapse group. During the 8-year follow-up period, the dental compensation was similar in both groups, but the mandible outgrew the maxilla by four times in the relapse group, compared with twice that in the stable group. In young individuals diagnosed with maxillary deficiency treated with reverse headgear and who have an immediate positive treatment response, there is a potential risk that about one-third might be candidates for orthognathic surgery later in life, because of an unfavourable growth pattern.

PMID: 12608729 [PubMed - indexed for MEDLINE]

Diurnal variation in the response of the mandible to orthopedic force.

J Dent Res. 2002 Oct;81(10):711-5

Authors: Yamada S, Saeki S, Takahashi I, Igarashi K, Shinoda H, Mitani H

Bone and cartilage metabolism is known to be more active during rest than during periods of activity. The purpose of this study was to examine the hypothesis that mandibular retractive force could be more effective when applied to rats during rest. Mandibular retractive force caused a considerable reduction in the condylar length in experimental groups, and the magnitude of this reduction was greater in the Light-period (08:00-20:00) group than in the Dark-period (20:00-08:00) group. The differentiation and proliferation of chondrocytes were inhibited in animals in the Light-period group, compared with those in the Dark-period group. These results suggest that the orthopedic effects of mandibular retractive force vary depending on the time of day the force is applied, and that such force may be more effective while animals are resting than while they are active.

PMID: 12351671 [PubMed - indexed for MEDLINE]

Combined orthodontic-dentofacial orthopedic treatment of a Class II Division 2 patient with severe deep bite.

J Orthod. 2002 Sep;29(3):181-8

Authors: Wong RW

PMID: 12218194 [PubMed - indexed for MEDLINE]

Bone strain patterns of the zygomatic complex in response to simulated orthopedic forces.

J Dent Res. 2002 Sep;81(9):608-12

Authors: Oberheim MC, Mao JJ

Craniofacial bone strain upon orthopedic loading has rarely been characterized, despite its fundamental importance in our understanding of the anabolic and catabolic effects of orthopedic forces. The present study tested the hypothesis that zygomatic bone strain is modulated upon loading by headgear, a device widely used in craniofacial orthopedics. Ramp forces from 0 to 50 Newtons were applied via headgear attached to the permanent maxillary first molars in four juvenile and five adult human skulls. The average peak bone strain of the juvenile temporal articular eminence was significantly higher than the adult articular eminence (p < 0.05). Contrasting bone strain patterns were identified in the zygomatic arch: tensile in its lateral surface but compressive in its medial surface. The peak bone strain of the temporal articular eminence and the zygomatic arch both depend upon loading direction. Thus, headgear-generated orthopedic forces evoke bending of the zygomatic arch and stresses of the temporal articular eminence in vitro, suggesting the need to verify whether bone strain induces in vivo bone modeling and remodeling.

PMID: 12202641 [PubMed - indexed for MEDLINE]

Orthodontic facebows: safety issues and current management.

J Orthod. 2002 Jun;29(2):101-7

Authors: Samuels RH, Brezniak N

Some patients treated with extra-oral traction provided by simple elasticated materials and a standard facebow have experienced problems with the standard facebow coming out of the buccal tubes at night and the catapult effect of the extra-oral traction. The disengagement of the facebow at night has affected the success of treatment and occasionally injured the patient. This paper draws on material from a variety of papers and lists the known causes and considers the associated safety issues. It also provides some clinical tips and makes several suggestions for the continued use of this very useful form of additional orthodontic anchorage.

PMID: 12114458 [PubMed - indexed for MEDLINE]

The British Orthodontic Society medal of the Intercollegiate M.Orth. of the Royal College of Surgeons of London and Glasgow 2001 and the William Houston medal of the M.Orth. of the Royal College of Surgeons of Edinburgh 2001.

J Orthod. 2002 Jun;29(2):83-95

Authors: Scholey J

PMID: 12114456 [PubMed - indexed for MEDLINE]

Effects of headgear Herbst and mandibular step-by-step advancement versus conventional Herbst appliance and maximal jumping of the mandible.

Eur J Orthod. 2002 Apr;24(2):167-74

Authors: Du X, H&#xE4;gg U, Rabie AB

The aims of this study were to compare dental and skeletal treatment changes in Class II division 1 malocclusions with two modes of maxillary control and two modes of bite-jumping. The subjects comprised Chinese children with severe Class II division 1 malocclusions, i.e. 21 consecutive subjects (13.4 +/- 1.4 years) treated with a headgear Herbst appliance and step-by-step advancement (HHSSA) of the mandible, and 24 consecutive subjects (13.2 +/- 1.4 years) treated with a 'conventional' Herbst appliance with maximal jumping (HMJ) of the mandible. Lateral cephalograms obtained at the start and end of treatment were analysed. The results showed that the improvement of the sagittal jaw relationship was significantly larger (2.9 mm; P < 0.001) in the HHSSA group than in the HMJ group due to the increased effect on the maxilla (-1.5 mm, P < 0.001) and the mandible (+1.4 mm, NS). There was no significant difference in the change in lower anterior face height, being 2.7 and 3.1 mm, respectively. The mandibular plane angle decreased significantly in the HHSSA group (-0.7 degree; P < 0.05) and increased insignificantly in the HMJ group (0.4 degree, NS), the difference being statistically significant (P < 0.01). The maxillary molars moved significantly more distally (1.1 mm, P < 0.05) and were intruded in the HHSSA group (-1.0 mm, P < 0.001) compared with a small extrusion in the HMJ group (+0.3 mm, NS), the difference being statistically significant (P < 0.001). There was no significant difference in the effect on the mandibular teeth. Treatment with HHSSA seems to result in a greater effect on the sagittal jaw relationship, improved vertical control and more maxillary molar movement. Mandibular anchorage loss was not reduced with step-by-step advancement of the mandible.

PMID: 12001553 [PubMed - indexed for MEDLINE]

The temporomandibular joint and the disc-condyle relationship after functional orthopaedic treatment: a magnetic resonance imaging study.

Eur J Orthod. 2001 Dec;23(6):683-93

Authors: Watted N, Witt E, Kenn W

Causative correction of Class II skeletal malocclusions may be achieved through bite jumping by various means. Numerous animal experiments have yielded evidence of remodelled temporomandibular structures after mandibular protrusion. However, the mode and extent of structural and/or topographic changes of the disc-condyle relationship after functional orthopaedic treatment is still unresolved. A problem exists in defining the physiological position of the condyles and disc-condyle relationship, which is tentatively determined by various methods particularly in magnetic resonance tomographic studies. Despite the high resolution provided, the results have to be interpreted with caution, as osseous resorption and apposition cannot be assessed by visual evidence. This investigation examined the impact on the temporomandibular joints (TMJ), i.e. the condylar shape and position, and the disc-condyle relationship, of the bionator plus extra-oral traction in combination with vertical elastics. The underlying reactions were studied by means of magnetic resonance images (MRI) obtained from n = 15 successfully treated patients (mean age 11.6 years).

PMID: 11890064 [PubMed - indexed for MEDLINE]

Fuzzy modelling for selecting headgear types.

Eur J Orthod. 2002 Feb;24(1):99-106

Authors: Ak&#xE7;am MO, Takada K

The purpose of this study was to develop a computer-assisted inference model for selecting appropriate types of headgear appliance for orthodontic patients and to investigate its clinical versatility as a decision-making aid for inexperienced clinicians. Fuzzy rule bases were created for degrees of overjet, overbite, and mandibular plane angle variables, respectively, according to subjective criteria based on the clinical experience and knowledge of the authors. The rules were then transformed into membership functions and the geometric mean aggregation was performed to develop the inference model. The resultant fuzzy logic was then tested on 85 cases in which the patients had been diagnosed as requiring headgear appliances. Eight experienced orthodontists judged each of the cases, and decided if they 'agreed', 'accepted', or 'disagreed' with the recommendations of the computer system. Intra-examiner agreements were investigated using repeated judgements of a set of 30 orthodontic cases and the kappa statistic. All of the examiners exceeded a kappa score of 0.7, allowing them to participate in the test run of the validity of the proposed inference model. The examiners' agreement with the system's recommendations was evaluated statistically. The average satisfaction rate of the examiners was 95.6 per cent and, for 83 out of the 85 cases, 97.6 per cent. The majority of the examiners (i.e. six or more out of the eight) were satisfied with the recommendations of the system. Thus, the usefulness of the proposed inference logic was confirmed.

PMID: 11887385 [PubMed - indexed for MEDLINE]

Early and late facemask therapy.

Eur J Orthod. 2001 Oct;23(5):559-68

Authors: Yüksel S, Uçem TT, Keykubat A

The purpose of this study was to determine the dental and skeletal effects of facemask therapy, and to evaluate the effect of age on treatment response. The material consisted of lateral cephalometric radiographs of 34 subjects with Class III malocclusions treated with a Delaire type facemask. Two groups of 17 patients each were formed: an early (six girls, 11 boys) and a late treatment group (eight girls, nine boys). At the beginning of treatment, the mean ages were 9 years 8 months for the early treatment group and 12 years 6 months for the late treatment group. The average treatment time was 7 months for both groups. A control group consisting of 17 children with a mean age of 9 years 5 months was formed that matched only the early treatment group according to age, and sagittal dental and skeletal relationships. To differentiate the orthodontic and total effects of the Delaire type facemask, superimpositions were made. In both treatment groups forward displacement of maxilla and an increase in overjet were found to be statistically significant (P < 0.01). Evaluation of total superimpositions showed that there was a significant displacement of maxillary molars and incisors (P < 0.05, early treatment group; P < 0.01, late treatment group), while no significant change was observed in local superimpositions. Changes in overjet and SNB in the early treatment group showed a significant difference compared with the control group (P < 0.001). The increase in Co-A and the decreases in the maxillo-mandibular differential and Wits' appraisal showed significant differences compared with the control group (P < 0.01). No significant difference was observed in skeletal and dental antero-posterior changes between the treatment groups.

PMID: 11668875 [PubMed - indexed for MEDLINE]

Three-dimensional finite element modelling of a dog skull for the simulation of initial orthopaedic displacements.

Eur J Orthod. 2001 Oct;23(5):517-27

Authors: Verrue V, Dermaut L, Verhegghe B

From 55 frontal tomograms (CT-scans) using the 'Patran' finite element processor, a three-dimensional finite element model (FEM) of a dog skull was constructed. The model was used to calculate bone displacements under orthopaedic loads. This required good representation of the complex anatomy of the skull. Five different entities were distinguished: cortical and cancellous bone, teeth, acrylic and sutures. The first model consisted of 3007 elements and 5323 nodes, including three sutures, and the second model 3579 elements and 6859 nodes, including 18 sutures. Prior to construction of the FEM, an in vivo study was undertaken using the same dog. The initial orthopaedic displacements of the maxilla were measured using laser speckle interferometry. Under the same loading conditions, using the second FEM, bone displacements of the maxilla were calculated and the results were compared with the in vivo measurements. Compared with the initial displacement measured in vivo, the value of the constructed FEM to simulate the orthopaedic effect of extra-oral force application was high for cervical traction and acceptable for anterior traction.

PMID: 11668871 [PubMed - indexed for MEDLINE]

The effect of zigzag elastics in the treatment of Class II division 1 malocclusion subjects with hypo- and hyperdivergent growth patterns. A pilot study.

Eur J Orthod. 2001 Aug;23(4):393-402

Authors: Aras A, Cinsar A, Bulut H

The aim of this study was to investigate the effect of zigzag elastics in the treatment of Class II division 1 malocclusion subjects with hypo- or hyperdivergent growth patterns. Two groups were established, each consisting of 10 subjects classified as hypo- or hyperdivergent according to their pre-treatment SN-GoGn angle. The cephalometric radiographs taken before and after an elastic application period of approximately 4 months were used to generate 22 variables. In both groups, there were no statistically significant differences in the vertical position of the lower molars, the SN-GoGn angle or the inclination of the lower incisors, whereas the sagittal skeletal relationship was improved as a result of an increase in the SNB angle and the mandibular length (P < 0.01). Upper incisor extrusion was statistically significant in both groups (P < 0.05). The downward rotation of the occlusal plane and the increase in overbite were found to be significant in the hypodivergent group (P < 0.05). Significant differences were observed between the groups in the extrusion of the upper incisor, the inclination of the occlusal plane, and the amount of overbite (P < 0.05). The results show that the zigzag elastic system is preferable, especially in hyperdivergent Class II division 1 subjects, as the use of such elastics does not cause an unfavourable effect on vertical jaw base relationship.

PMID: 11544789 [PubMed - indexed for MEDLINE]

The influence of orthodontic extraction treatment on dental structures: a two-factor evaluation.

Eur J Orthod. 2001 Jun;23(3):295-303

Authors: Darendeliler N, Taner-Sarisoy L

The purpose of this investigation was to evaluate the effects of different growth patterns and treatment types on dentoalveolar structures in patients treated with fixed Edgewise mechanics and the extraction of four first premolars. A total of 41 patients with a mean chronological age of 14 years 7 months and skeletal age of 14 years 6 months were included in the study. The type of growth pattern was assessed as mesio- or hyper-divergent, and the treatment type as the use or non-use of headgear. The results were analysed by two-way analysis of variance (ANOVA). The decrease in overbite in the mesiodivergent group was statistically significant when compared with the increase in the hyper-divergent group (P < 0.01). Extrusion of the lower molar was observed in all groups, and a statistically significant difference was found between the mesio- and hyper-divergent groups (P < 0.05). Interaction between growth pattern and treatment type was not found to be significant for any variable. It can be concluded that premolar extractions and the use of headgear with fixed appliances does not significantly change the overjet, occlusal plane angle, upper and lower anterior dentoalveolar heights, upper posterior dentoalveolar height, or the inclination of the upper and lower incisors. The only significant changes were observed in overbite as a result of treatment mechanics and in lower posterior dentoalveolar height due to the growth pattern.

PMID: 11471272 [PubMed - indexed for MEDLINE]

Location of the centre of resistance of the upper dentition and the nasomaxillary complex. An experimental study.

Eur J Orthod. 2001 Jun;23(3):263-73

Authors: Billiet T, de Pauw G, Dermaut L

The purpose of this study was to investigate the initial displacement of the upper dentition and the nasomaxillary complex as a result of different directions of force application, and to determine the initial centres of resistance for both the upper dentition and the nasomaxillary complex. A macerated human skull with a well-aligned upper arch was used as one experimental model and Araldit 208 as a substitute for the periodontal ligament (PDL). Specifically designed 'antenna-headgear' was developed in an attempt to create different points of force application to simulate high-pull and horizontal traction, and orthopaedic force magnitudes of 8 N were applied to the upper dentition and the nasomaxillary complex. Double exposure holography was used to measure the initial displacement. Reproducibility of the technique was tested and found to be reliable. According to the registered fringe patterns, the force application transmitted by the headgear resulted in complex displacement of facial bones. Pure translation of the maxilla and the upper dentition was observed when the force vector passed by in the area of the key-ridge. No obvious difference was found between the centre of resistance of the upper dentition and the nasomaxillary complex. The location of two different centres of resistance could not be confirmed by measuring initial displacements on this macerated human skull.

PMID: 11471269 [PubMed - indexed for MEDLINE]

A prospective optical surface scanning and cephalometric assessment of the effect of functional appliances on the soft tissues.

Eur J Orthod. 2001 Apr;23(2):115-26

Authors: McDonagh S, Moss JP, Goodwin P, Lee RT

The aim of this study was to evaluate the effect of different functional appliances on the soft tissues as assessed by cephalometry and optical surface scanning. Forty-two patients were randomly allocated to Bass, Twin Block (TB), and Twin Block + Headgear (TB + Hg) groups. Lateral cephalograms and optical surface scans were recorded before and after the 10-month study period. ANOVA was used to test the cephalometric variables for differences at the 5 per cent level. The optical surface scanning and cephalometric results were consistent in the sagittal dimension. In the vertical dimension, however, the optical surface scans consistently recorded a greater increase compared with cephalometric values. No differences were detected with regard to cephalometric values at the 5 per cent level. However, the Bass appliance produced greater forward positioning of soft tissue pogonion as assessed by optical surface scanning.

PMID: 11398549 [PubMed - indexed for MEDLINE]

The effect of micro-etching on the retention of orthodontic molar bands: a clinical trial.

Eur J Orthod. 2001 Feb;23(1):91-7

Authors: Hodges SJ, Gilthorpe MS, Hunt NP

Failure of orthodontic bands occurs most frequently at the band-cement interface, when conventional glass ionomer cements are used. Modification of the band surface may improve clinical performance by increasing the mechanical interlock at this junction. The aim of this prospective study was to compare the retention of micro-etched and untreated first molar orthodontic bands in a randomized, half-mouth trial. Seventy-nine patients had 304 bands cemented as part of routine fixed appliance therapy. The effect of micro-etching, patient age and gender, operator, molar crossbite, treatment mechanics, and arch on band failure was investigated. Failure rates and survival times were compared for each variable assessed. Micro-etched molar bands showed a significant reduction in clinical failure rate over untreated molar bands and an increase in mean survival time (P < 0.001). Of the other variables examined, only the presence of a molar crossbite had any significant effect on band failure (P = 0.004).

PMID: 11296514 [PubMed - indexed for MEDLINE]

Class II correction-reducing patient compliance: a review of the available techniques.

J Orthod. 2000 Sep;27(3):219-25

Authors: McSherry PF, Bradley H

The correction of Class II malocclusions has been hampered by the use of appliances which require the patient to co-operate with headgear, elastics, or the wearing of a removable appliance. 'Non-compliance therapy' involves the use of appliances which minimize the need for such co-operation and attempt to maximize the predictability of results. This article reviews and describes the types of appliances used, and their mode of action-based on the current available research.

PMID: 11099554 [PubMed - indexed for MEDLINE]

The changes in temporomandibular joint disc position and configuration in early orthognathic treatment: a magnetic resonance imaging evaluation.

Eur J Orthod. 2000 Jun;22(3):217-24

Authors: G&#xF6;kalp H, Arat M, Erden I

This study aimed to examine the effects of chin cup therapy on the temporomandibular joint (TMJ) disc position and configuration with magnetic resonance imaging (MRI). Twenty-five individuals ranging in age from 5 to 11 years were evaluated. The treatment group consisted of 15 subjects (10 females and five males) with prognathic facial structures, while the control group comprised 10 subjects (six females and four males) with an orthognathic facial structure. The magnitude of the chin cup force applied to the mandible was 600 g. Unilateral MRIs of the TMJ were taken in all subjects at the beginning and end of the study. No statistically significant changes in the TMJ disc position and configuration during the treatment and control periods could be seen. The values of the alpha angle measurements were found to be different in the treatment and control groups at the beginning (166.23 +/- 2.15 and 172 +/- 1.97, respectively), and end of the treatment and control periods (160.00 +/- 2.16 and 172.00 +/- 2.68). These findings show that if the chin cup appliance is used at an early age and with appropriate forces, there will be no adverse effect on the TMJ disc position and configuration.

PMID: 10920553 [PubMed - indexed for MEDLINE]

Effect of wearing cervical headgear on tongue pressure.

J Orthod. 2000 Jun;27(2):163-7

Authors: Takahashi S, Ono T, Ishiwata Y, Kuroda T

The purpose of this study was to examine whether wearing cervical headgear affected tongue pressure on the lingual surface of mandibular incisors, with particular attention to suprahyoid muscle activity. Tongue pressure was recorded using a miniature pressure sensor without cervical headgear and with two cervical headgears with traction forces of 500 and 1200 g, respectively. Electromyographic activity of suprahyoid muscles and respiratory-related movement were recorded simultaneously. Wearing cervical headgear significantly affected tongue pressure and suprahyoid muscle activity in the short-term. A significant increase in tongue pressure was observed in association with an increase in traction force from 500 to 1200 g, whereas no significant difference in suprahyoid muscles activity was seen between these force levels. These results suggest that wearing cervical headgear increases tongue pressure on the lingual surface of mandibular incisors, and this increase in tongue pressure may result from changes in the electromyographic activity of suprahyoid muscles to maintain adequate pharyngeal patency.

PMID: 10867072 [PubMed - indexed for MEDLINE]

Forestadent Travel Award.

J Orthod. 2000 Jun;27(2):127-33

Authors: Russell JI

PMID: 10867068 [PubMed - indexed for MEDLINE]

A comparison of chincap and maxillary protraction appliances in the treatment of skeletal Class III malocclusions.

Eur J Orthod. 2000 Feb;22(1):43-51

Authors: U&#xE7;üncü N, Uçem TT, Yüksel S

The purpose of this retrospective investigation was to compare cephalometrically the treatment effects of chincap and maxillary protraction appliances in subjects with a Class III skeletal malocclusion with a combination of an underdeveloped maxilla and prominent mandible. Twenty-four patients were divided into two groups according to the treatment type; the chincap group (mean age 11.03 years, n = 12) and the Delaire type maxillary protraction appliance group (mean age 10.72 years, n = 12). In both groups, a significant increase in ANB, molar relationship, and overjet showed the effect of the appliances in the treatment of Class III malocclusions. In comparing the two groups, the maxilla was displaced more anteriorly and the molar relationship correction was greater in the maxillary protraction appliance group (P < 0.05). Angular and dimensional parameters for lower incisor/NB and nasolabial angle showed significant differences between the groups (P < 0.05).

PMID: 10721244 [PubMed - indexed for MEDLINE]

A medico-legal review of some current UK guidelines in orthodontics: a personal view.

Br J Orthod. 1999 Dec;26(4):307-24

Authors: Jones JW

This article is a critical analysis from a medico-legal perspective of some current authoritative UK clinical guidelines in orthodontics. Two clinical guidelines have been produced by the Royal College of Surgeons of England and four by the British Orthodontic Society. Each guideline is published with the analysis immediately following it. Following recent UK case law (Bolitho v City & Hackney Health Authority, 1997) which allows the courts to choose between two bodies of responsible expert medical opinion where they feel one opinion is not 'logical', it is likely that the UK courts will increasingly turn to authoritative clinical guidelines to assist them in judging whether or not an appropriate standard of care has been achieved in medical negligence cases. It is thus important for clinicians to be aware of the recommendations of such guidelines, and if these are not followed the reasons should be discussed with the patient and recorded in the clinical case notes. This article attempts to highlight aspects of the guidelines that have medico-legal implications.

PMID: 10592160 [PubMed - indexed for MEDLINE]

Optident-ormco 'A' company prize 1998.

Br J Orthod. 1999 Dec;26(4):261-8

Authors: O'Malley AM

PMID: 10592152 [PubMed - indexed for MEDLINE]

Thin-plate spline analysis of treatment effects of rapid maxillary expansion and face mask therapy in early Class III malocclusions.

Eur J Orthod. 1999 Jun;21(3):275-81

Authors: Baccetti T, Franchi L, McNamara JA

An effective morphometric method (thin-plate spline analysis) was applied to evaluate shape changes in the craniofacial configuration of a sample of 23 children with Class III malocclusions in the early mixed dentition treated with rapid maxillary expansion and face mask therapy, and compared with a sample of 17 children with untreated Class III malocclusions. Significant treatment-induced changes involved both the maxilla and the mandible. Major deformations consisted of forward displacement of the maxillary complex from the pterygoid region and of anterior morphogenetic rotation of the mandible, due to a significant upward and forward direction of growth of the mandibular condyle. Significant differences in size changes due to reduced increments in mandibular dimensions were associated with significant shape changes in the treated group.

PMID: 10407536 [PubMed - indexed for MEDLINE]