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]

A systematic review of cephalometric facial soft tissue changes with the Activator and Bionator appliances in Class II division 1 subjects.

Eur J Orthod. 2006 Dec;28(6):586-93

Authors: Flores-Mir C, Major PW

The objective of the present systematic review was to evaluate, through lateral cephalograms, facial soft tissue changes after the use of the Activator and Bionator appliances in Class II division 1 malocclusion subjects. Several electronic databases (PubMed, Medline, Medline In-Process and Other Non-Indexed Citations, Cochrane Database, Embase, Web of Sciences, and Lilacs) were searched with the assistance of a senior health sciences librarian. Abstracts, which appeared to fulfil the initial criteria, were selected by consensus. The original articles were then retrieved. Their references were also hand searched for possible missing articles. Clinical trials, which assessed facial soft tissue changes with the use of either an Activator or a Bionator appliance without any surgical intervention or syndromic characteristics, were considered. A comparable untreated control group was required to factor out normal growth changes. Five articles using the Activator and six using the Bionator fulfilled the selection criteria and quantified facial soft tissue changes. An individual analysis of these articles was undertaken and some methodological flaws were identified. Based on the available evidence, a significant amount of controversy regarding the soft tissue changes produced by the Activator and the Bionator exists. Soft tissue changes that were reported as being statistically significant were of questionable clinical significance. Long-term, double-blinded, prospective randomized clinical trials are needed to confirm the findings. Three-dimensional quantification is also required to overcome current limitations in our understanding of the soft tissue changes obtained with the use of removable functional appliances.

PMID: 17095741 [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]

Oral applicances for obstructive sleep apnea?

Am Fam Physician. 2006 Mar 1;73(5):801-3

Authors: Cook V, Schooff M

PMID: 16529085 [PubMed - indexed for MEDLINE]

The treatment effects of Invisalign orthodontic aligners: a systematic review.

J Am Dent Assoc. 2005 Dec;136(12):1724-9

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

BACKGROUND: The authors conducted a systematic review of the literature to determine the treatment effects of the Invisalign orthodontic system (Align Technology), Santa Clara, Calif.). TYPES OF STUDIES REVIEWED: The authors reviewed clinical trials that assessed Invisalign's treatment effects in nongrowing patients. They did not consider trials involving surgical or other simultaneous fixed or removable orthodontic treatment interventions. RESULTS: The authors searched electronic databases (PubMed, MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, Evidence Based Medicine Reviews, EMBASE Excerpta Medica, Thomsen's ISI Web of Science and LILACS) with the help of a senior health sciences librarian. They used "Invisalign" as the sole search term, and 22 documents appeared in the combined search. Thereafter, they used "clinical trials," "humans" and "Invisalign treatment effects" as abstract selection criteria. Only two published articles met these inclusion criteria, though after reading the actual articles, the authors determined that they did not adequately evaluate Invisalign treatment effects. Both articles identified methodological issues. CLINICAL IMPLICATIONS: The inadequately designed studies the authors found represented only a lower level of evidence (level II). Therefore, the authors found that no strong conclusions could be made regarding the treatment effects of Invisalign appliances. Future prospective randomized clinical trials are required to support, with sound scientific evidence, the claims about Invisalign's treatment effects. Clinicians will have to rely on their Invisalign clinical experience, the opinions of experts and the limited published evidence when using Invisalign appliances.

PMID: 16383056 [PubMed - indexed for MEDLINE]

Localized sequential use of resilient lining to generate orthodontic force in thermoformed active removable appliances.

J Orthod. 2005 Dec;32(4):235-40

Authors: Ng EW

A new modality of orthodontic treatment based on the thermoformed appliance was developed and trialled clinically. A light-cured resilient lining material commonly used for denture relining was placed locally and sequentially in thermoformed appliances to generate orthodontic forces. The new method appeared to be effective. All the presented cases showed substantial improvement in dental alignment. A number of orthodontic movements were demonstrated. Localized use of resilient lining in thermoformed orthodontic appliances appeared to be a promising alternative to other thermoformed active removable appliance (TARA) treatments. Further studies are required to optimize the procedures and explore its full potential.

PMID: 16333043 [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]

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]

Adaptive condylar growth and mandibular remodelling changes with bionator therapy--an implant study.

Eur J Orthod. 2004 Oct;26(5):515-22

Authors: Araujo AM, Buschang PH, Melo AC

The purpose of this study was to describe condylar growth and mandibular remodelling changes associated with bionator therapy. Twenty-five patients (15 males and 10 females) between 6.9 and 11.2 years of age with Class II division 1 malocclusions were randomly allocated to either control (n = 11) or treatment (n = 14; bionator only) groups and followed longitudinally for approximately 1 year. Treatment consisted of a bionator only, constructed to clear the buccal dentition by 2 mm and to position the mandible into an edge-to-edge incisor relationship. Using metallic implants for superimposition, mandibular growth, displacement, and true rotation were evaluated cephalometrically. The results showed significant changes in the direction (more posterior) but not in the overall amount of condylar growth. The bionator appliance produced greater than expected posterior drift of landmarks in the condylar and gonial regions. Cranial base superimposition showed greater than expected anterior mandibular displacement, but little or no true mandibular forward rotation with bionator therapy. The bionator appliance alone produced changes in condylar growth direction and remodelling changes associated with mandibular rotation and displacement.

PMID: 15536840 [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]

Dentoskeletal effects and facial profile changes during activator therapy.

Eur J Orthod. 2004 Jun;26(3):293-302

Authors: Cozza P, De Toffol L, Colagrossi S

The aim of this retrospective study was to investigate cephalometrically the skeletal, dental, and soft tissue modifications induced by activator treatment in patients with Class II malocclusions caused by mandibular retrognathism. The subjects, all in the mixed dentition, were selected from a single centre and were divided into two groups: 40 patients treated with an incisor double capping activator (20 girls, 20 boys with a mean age of 10 years) and a control group of 30 subjects (15 girls, 15 boys with a mean age of 10 years). The dentoskeletal and aesthetic changes that occurred were compared on lateral cephalograms taken before treatment (T0) and after 18-24 months, when the activator was removed (T1). In the control group the radiographs were obtained before (T0) and after (T1) 21 months (standard deviation +/- 3 months). Activator treatment in these growing patients resulted in a correction of the Class II relationship (ANB -2.14 degrees), a restriction of maxillary growth (SNA -0.5 degrees), an advancement of the mandibular structures (SNB +1.64 degrees, FH--NPg +3.39 degrees; OLp-B +5.17 mm, OLp-Pg +5.14 mm, OLp-Go +2.44 mm), a correction of the overjet (-5.03 mm), an improvement in overbite (-1.17 mm) and uprighting of the maxillary incisors (1--FH -5.64 degrees). The activator appliance was effective in treating growing patients with mandibular deficiency: activator therapy corrected Class II malocclusions by a combination of skeletal and dental changes and improved the soft tissue facial profile.

PMID: 15222715 [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]

Treatment effects produced by the Bionator appliance. Comparison with an untreated Class II sample.

Eur J Orthod. 2004 Feb;26(1):65-72

Authors: Almeida MR, Henriques JF, Almeida RR, Almeida-Pedrin RR, Ursi W

The purpose of this retrospective investigation was to evaluate the dentoalveolar and skeletal cephalometric changes of the Bionator appliance on individuals with a Class II division 1 malocclusion. Lateral cephalograms of 44 patients were divided into two equal groups. The control group comprised 22 untreated Class II children (11 males, 11 females), with an initial mean age of 8 years 7 months who were followed without treatment for a period of 13 months. The Bionator group (11 males, 11 females) had an initial mean age of 10 years 8 months, and were treated for a mean period of 16 months. Lateral cephalometric headfilms were obtained of each patient and control at the beginning and end of treatment. The results showed that there were no changes in forward growth of the maxilla in the experimental group compared with the control group. However, the Bionator treatment produced a statistically significant increase in mandibular protrusion, and in total mandibular and body lengths. There were no statistically significant differences in craniofacial growth direction between the Bionator group and the control group, although the treated patients demonstrated a greater increase in posterior face height. The Bionator appliance produced labial tipping of the lower incisors and lingual inclination of the upper incisors, as well as a significant increase (P < 0.01) in mandibular posterior dentoalveolar height. The major effects of the Bionator appliance were dentoalveolar, with a smaller significant skeletal effect. The results indicate that the correction of a Class II division 1 malocclusion with the Bionator appliance is achieved not only by a combination of mandibular skeletal effects, but also by significant dentoalveolar changes.

PMID: 14994884 [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: G&#xF6;yenç 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]

[The feasibility and reliability of Pancherz's analysis in evaluating the treatment effects of bite-jumping on skeletal class II malocclusion]

Shanghai Kou Qiang Yi Xue. 2003 Aug;12(4):256-9

Authors: Chen RJ, Shen G

OBJECTIVE: This study was designed to conduct an in-depth evaluation on Pancherz's analysis. METHODS: A typical Class II case with bite-jumping therapy was selected for the whole process of Pancherz's Analysis. The skeletal growth modification and dental compensation were examined and portioned for their respective contribution to the correction of excessive overjet and Class II molar relationship. RESULTS: The following traits and properties of Pancherz's analysis were found: (1) A fixed reference system characterized by SN and OLp was established which led to an accurate detection of the moving objects. (2) Skeletal and dental changes were separated for evaluation, which resulted in a true assessment of the bite-jumping on growth pattern modification.(3) A segmental examination for dental changes indicated the magnitude of skeletal modification. Conclusion Pancherz's analysis is a feasible and reliable evaluation system which could reflect with accuracy the skeletal and dental effects caused by bite-jumping therapy.

PMID: 14966635 [PubMed - indexed for MEDLINE]

Temporomandibular response to early and late removal of bite-jumping devices.

Eur J Orthod. 2003 Oct;25(5):465-70

Authors: Chayanupatkul A, Rabie AB, H&#xE4;gg U

This study was designed to monitor the amount of bone formed after 'early' and 'late' removal of bite-jumping devices and to compare it with that of normal growth. One hundred and thirty-five 35-day-old female Sprague-Dawley rats were randomly divided into seven control (n = 5) and 10 experimental (n = 10) groups. Appliances were fitted to position the mandible forward in the experimental groups. On day 30, the bite-jumping device was removed in two groups ('early' removal) and the rats were sacrificed on days 44 and 60. On day 44 the device was removed in one group ('late' removal) and the rats were sacrificed on day 60. The full-time wear and matched control animals were then sacrificed at different time points. Tissue sections (7 microm) were cut through the temporomandibular joint (TMJ) in the sagittal plane and stained with periodic acid and Schiff's reagent for the evaluation of new bone formation. Newly formed bone was measured using a computer-assisted image analysing system. The results showed that, in the condyle, early removal of the appliance resulted in less bone formation when compared with that of natural growth. Late removal of the appliance resulted in bone formation similar to that of natural growth. In the glenoid fossa, the level of bone formation was similar to that of the control at early and late removal of the appliance. In conclusion, early appliance removal results in subnormal growth of the posterior condyle but not of the glenoid fossa. Increasing the length of mandibular advancement secures normal levels of mandibular growth in the post-treatment period.

PMID: 14609014 [PubMed - indexed for MEDLINE]

Pseudo-Class III malocclusion treatment with Balters' Bionator.

J Orthod. 2003 Sep;30(3):203-15

Authors: Giancotti A, Maselli A, Mampieri G, Spanò E

The aim of this article is to show the use of the Balters' Bionator in pseudo-Class III treatment. The importance of differentiating between true Class III and pseudo-Class III is emphasized. The therapeutic results of a Balters' Bionator appliance are presented in three case reports of subjects in the mixed dentition. In this stage of development it is possible to correct an isolated problem. The use of the Bionator III in this kind of malocclusion enabled the correction of a dental malocclusion in a few months and therapeutic stability of a mesially-positioned mandible encouraging favourable skeletal growth.

PMID: 14530417 [PubMed - indexed for MEDLINE]

Contemporary treatment of a crowded Class II division 1 case.

J Orthod. 2003 Jun;30(2):119-26

Authors: Lowe CI

A 12-year-old Caucasian male presented with a severe Class II division 1 incisor relationship on a mild Skeletal II base with an average maxillary-mandibular planes angle and average lower facial height. Crowding was severe in the upper arch and moderate in the lower arch. Treatment was commenced using Twin Block appliances, and followed by extractions in all four quadrants and fixed appliances. This case illustrates the versatility of the Twin Block appliance in the treatment of those cases exhibiting crowding.

PMID: 12835427 [PubMed - indexed for MEDLINE]

The effects of activator treatment on the craniofacial structures of Class II division 1 patients.

Eur J Orthod. 2003 Feb;25(1):87-93

Authors: Basciftci FA, Uysal T, Büyükerkmen A, Sari Z

The aim of the present study was to clarify the skeletal treatment effects induced by activator treatment. Fifty actively growing patients with Class II division 1 malocclusions were treated with an activator appliance. A control group consisting of longitudinal growth data from 20 patients (untreated Class II division 1 malocclusions) was used to eliminate possible differences in growth pattern. Lateral cephalograms of each patient were taken at the start and end of treatment. Final cephalograms were taken after a mean of 16.4 (+/- 2.0) months activator treatment, compared with a mean of 14.2 (+/- 2.4) months for the control group. Each cephalogram was traced and digitized by the same individual. The mean and standard deviations for linear and angular cephalometric measurements were analysed statistically, and intra- and inter-group changes were evaluated by paired- and independent-sample t-tests. At the end of the study period, the overjet was decreased in all patients. Ramus height, corpus length, anterior and posterior face height all increased significantly (P < 0.05). In the treatment group, ANB angle decreased and the bite was opened. The activator appliance caused maxillary incisor lingual tipping and mandibular incisor labial tipping. The overjet was decreased as a result of the increased forward growth of the mandible and dentoalveolar changes. The results demonstrated that the activator appliance has a characteristic skeletal and dental effect on the developing craniofacial complex.

PMID: 12608728 [PubMed - indexed for MEDLINE]

Effective temporomandibular joint growth and chin position changes: Activator versus Herbst treatment. A cephalometric roentgenographic study.

Eur J Orthod. 2002 Dec;24(6):627-37

Authors: Baltromejus S, Ruf S, Pancherz H

In 138 successfully treated Class II division 1 patients (40 Activator and 98 Herbst) effective temporomandibular joint (TMJ) growth changes (a summation of condylar remodelling, glenoid fossa remodelling, and condylar position changes within the fossa), and their influence on the position of the chin and the rotation of the mandible were analysed retrospectively. Lateral head films in habitual occlusion from before and after an average treatment period of 2.6 years for the Activator patients and 0.6 years for the Herbst patients were evaluated. Two different treatment changes were assessed: (1) overall growth changes and (2) treatment effects (overall growth changes minus age-related normal growth values: Bolton Standards). The comparison between the Activator and the Herbst group revealed larger effective TMJ and chin changes during Activator therapy due to the longer observation period (2.6 years versus 0.6 years). The treatment effects showed marked group differences for both the amount and direction of effective TMJ changes. The changes were vertical and slightly anterior in the Activator group, and predominantly posterior in the Herbst group. Concerning the chin changes, the treatment effects for the Herbst group exceeded those for the Activator group in both directions, caudally and anteriorly. The Activator group showed an anterior rotation and the Herbst group a slight posterior rotation of the mandible. The present investigation revealed that the effective TMJ and chin changes were increased by both Activator and Herbst treatment. However, the Herbst appliance renders more favourable sagittally orientated treatment effects in a much shorter period of time compared with the Activator.

PMID: 12512780 [PubMed - indexed for MEDLINE]

A comparative study of two mandibular advancement appliances for the treatment of obstructive sleep apnoea.

Eur J Orthod. 2002 Apr;24(2):191-8

Authors: Rose E, Staats R, Virchow C, Jonas IE

Mandibular advancement appliances (MAAs) are accepted as a treatment option for snoring and mild obstructive sleep disorders. In the present clinical study two differently designed devices were examined for their effectiveness in treating obstructive sleep apnoea (OSA). The study was based on an assessment of 26 patients with a polysomnographic diagnosis of mild OSA [22 men, four women; mean body mass index 27.3 kg/m2 (SD 3.1); mean age 56.8 years (SD 5.2); mean respiratory disturbance index (RDI): 16.0 events/hour (SD 4.4)]. After insertion of the first MAA and a 6-8-week habituation period, a cardio-respiratory home-sleep study was carried out. Following a 2-3-week period with no treatment, the second appliance was inserted. The sequence of the devices was randomized. Once the patients had become accustomed to the second appliance, another somnographic registration was carried out. Daytime sleepiness, snoring, and sleep quality were assessed subjectively on a visual analogue scale. The results showed that a statistically significant improvement in the respiratory parameters was achieved with both appliances (P < 0.01). However, the activator [RDI: 5.5 events/hour, SD 3.3; apnoea index (AI): 3.4 events/hour, SD 2.1] was significantly more effective (P < 0.01) than the Silencor (RDI, 7.3 events/hour, SD 5.3; AI: 5.8 events/hour, SD 3.2). No difference was recorded in the subjective assessment of the therapeutic effects. Both appliances reduced daytime sleepiness and snoring and improved sleep quality, and both influenced the treatment outcome.

PMID: 12001556 [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]

Mandibular advancement device in patients with obstructive sleep apnea : long-term effects on apnea and sleep.

Chest. 2001 Jul;120(1):162-9

Authors: Marklund M, Sahlin C, Stenlund H, Persson M, Franklin KA

STUDY OBJECTIVES: To evaluate the long-term effects on apneas and sleep and the tolerability of a mandibular advancement device in patients with obstructive sleep apnea. DESIGN: Prospective study. SETTING: Department of Respiratory Medicine, University Hospital, Ume&#xE5;, Sweden. PATIENTS: Thirty-three consecutively treated patients. INTERVENTIONS: Individually adjusted mandibular advancement devices. Measurements and results: Polysomnographic sleep recordings on 1 night without the device and 1 night with the device were performed after 0.7 +/- 0.5 years (mean +/- SD) and after 5.2 +/- 0.4 years from the start of treatment. Nineteen of the 33 patients experienced a short-term satisfactory treatment result with an apnea-hypopnea index of < 10 events per hour and a satisfactory reduction in snoring. Fourteen patients were regarded as being insufficiently treated with the device. Seventeen of the short-term satisfactorily treated patients (90%) and 2 of the remaining patients continued treatment on a long-term basis. The apnea-hypopnea index was reduced by the device from 22 +/- 17 to 4.9 +/- 5.1 events per hour (p < 0.001) in these 19 long-term treatment patients, which did not differ from what was found at the short-term follow-up visits in these patients. Patients with their devices replaced or adjusted experienced a better long-term effect than patients still using their original devices (p < 0.05). CONCLUSIONS: The long-term effect and tolerability of a mandibular advancement device are good in patients who are recommended the treatment on the basis of a short-term sleep recording, provided that the device is continuously adjusted or replaced with a new one when needed. A short-term follow-up is valuable in the selection of patients who will benefit from long-term treatment with a mandibular advancement device.

PMID: 11451833 [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]

Class II combination therapy (distal jet and Jasper Jumpers): a case report.

J Orthod. 2000 Sep;27(3):213-8

Authors: Bowman SJ

Class II combination therapy is a method that combines orthodontic and orthopedic mechanics in a single stage of treatment. Molar distalization is followed by fixed functional mechanics to reduce the dependence upon patient compliance while seeking more predictable completion of Class II correction.

PMID: 11099553 [PubMed - indexed for MEDLINE]

Elastic activator for treatment of open bite.

Br J Orthod. 1999 Jun;26(2):89-92

Authors: Stellzig A, Steegmayer-Gilde G, Basdra EK

This article presents a modified activator for treatment of open bite cases. The intermaxillary acrylic of the lateral occlusal zones is replaced by elastic rubber tubes. By stimulating orthopaedic gymnastics (chewing gum effect), the elastic activator intrudes upper and lower posterior teeth. A noticeable counterclockwise rotation of the mandible was accomplished by a decrease of the gonial angle. Besides the simple fabrication of the device and uncomplicated replacement of the elastic rubber tubes, treatment can be started even in mixed dentition when affixing plates may be difficult.

PMID: 10420241 [PubMed - indexed for MEDLINE]

A prospective evaluation of Bass, Bionator and Twin Block appliances. Part II--The soft tissues.

Eur J Orthod. 1998 Dec;20(6):663-84

Authors: Morris DO, Illing HM, Lee RT

A prospective clinical study with a random allocation of 47 patients to three different functional appliance groups was established and compared with a slightly younger control group over a 9-month period. The cephalometric hard tissue changes were assessed in relation to the soft tissue changes produced and the patients were also assessed by three-dimensional (3D) laser scanning of the facial soft tissues. Each 'averaged' appliance group scan was compared with the 'averaged' control group face. Statistically and clinically significant changes occurred in the group treated with the Twin Block appliance, and to a lesser extent in the group treated with the Bionator appliance. No statistically significant facial soft tissue changes could be demonstrated in the Bass appliance group. Upper lip position remained stable despite the significant overjet reduction attained in the three appliance groups. Lower lip protrusion (up to 3.8 mm), lower lip length (up to 4.0 mm), and soft tissue lower and total face height increased significantly in all appliance groups by varying amounts. The long-term effect of these changes needs to be fully evaluated. The laser scanning system was found to be a sensitive and accurate method of quantitatively assessing small changes in the soft tissue facial form. Significant changes of the facial tissues in the transverse plane were highlighted by this technique.

PMID: 9926634 [PubMed - indexed for MEDLINE]

A comparative assessment of acceptance of different types of functional appliances.

Eur J Orthod. 1998 Oct;20(5):517-24

Authors: Sergl HG, Zentner A

Patients' acceptance of an orthodontic appliance may influence compliance and thus contribute to a successful outcome of treatment. The aim of this study was to assess the influence of shape and design of different types of functional appliances on their acceptance by patients. For each of 10 adult volunteer subjects employed in the study eight different functional appliances were fabricated which had a varying extension of the resin base and amount of interocclusal opening. Effects of appliances on speech, initial acceptance, and acceptance after wearing were assessed by means of standardized tests. Amongst the appliances tested the bionator, functional corrector FR-I and elastic open activator showed the highest acceptance by the test subjects. The results of the study indicate that there is a considerable difference in acceptance of various types of functional appliances.

PMID: 9825554 [PubMed - indexed for MEDLINE]

A prospective evaluation of Bass, Bionator and Twin Block appliances. Part I--The hard tissues.

Eur J Orthod. 1998 Oct;20(5):501-16

Authors: Illing HM, Morris DO, Lee RT

A prospective clinical study with a random allocation of 47 adolescent patients to three different functional appliance groups was established and compared with an untreated control group over a 9-month period. Treatment was undertaken with either a Bionator, Twin Block, or Bass appliance. Pre- and post-treatment cephalograms were used to quantify the skeletal and dentoalveolar changes produced by the appliances and compared with those observed in the control group as a result of growth. Both the Bionator and Twin Block appliances demonstrated a statistically significant increase in mandibular length (3.9 +/- 2.7 mm; 3.7 +/- 2.1 mm, respectively) compared with the control group (P < 0.05), with an anterior movement of pogonion and point B. Highly statistically significant increases (P < 0.01) were seen in lower face heights for all the appliance groups compared with the control group. The Twin Block group showed the least forward movement of point A due to a change in the inclination of the maxillary plane. The Bionator and Twin Block groups showed statistically significant reductions in the inclination of the upper incisors to the maxillary plane (P < 0.05). The Bass group showed minimal change in the inclination of the lower labial segment to the mandibular plane. The Bionator group demonstrated the greatest proclination of the lower labial segment (4.0 +/- 3.6 degrees). Clinically important changes were measured in all the appliance groups when compared with the control group. Differences were also identified between the functional appliance groups. The Twin Block appliance and, to a lesser extent, the Bionator appeared the most effective in producing sagittal and vertical changes.

PMID: 9825553 [PubMed - indexed for MEDLINE]

The initial effects of the treatment of Class II, division 1 malocclusions with the van Beek activator compared with the effects of the Herren activator and an activator-headgear combination.

Eur J Orthod. 1998 Aug;20(4):389-97

Authors: Altenburger E, Ingervall B

The effects of the van Beek activator in the correction of Class II, division 1 malocclusions were studied in 39 children, aged 9-13 years (median 11 years), and compared with the effects of treatment with an activator according to Herren and with those of an activator-headgear combination. Profile cephalograms were made before treatment and at the attainment of a Class I molar relationship (median observation time 9 months). The median improvement of the overjet was 4.7 mm and of the molar relationship 3.6 mm. This was largely achieved skeletally by in increase in mandibular prognathism while the skeletal effect on the maxilla was clinically insignificant. The maxillary incisors retroclined and the mandibular incisors proclined moderately. In general, no intrusion of the maxillary incisors was found and the eruption of the molars could not be stopped. The effects differed partly between the sexes, with a larger mandibular skeletal and molar reaction in the boys and a larger maxillary molar movement in girls. The larger mandibular reaction in the boys might have been due to the on average 4.5 months longer treatment time. The skeletal effects of the treatment were similar with all three activator types. The control of the incisors was, however, superior with the van Beek activator, especially when compared with the Herren activator.

PMID: 9753820 [PubMed - indexed for MEDLINE]

The use of the Jasper Jumper for the correction of Class II malocclusion in the young permanent dentition.

Eur J Orthod. 1998 Jun;20(3):271-81

Authors: Stucki N, Ingervall B

The effect of the Jasper Jumper in the treatment of Class II, division 1 malocclusions was studied in 26 consecutive 13-25-year-old patients. The median treatment time was 5 months, followed by a median period of observation or retention of 7 months. The effects of the treatment were evaluated from cephalograms taken before the treatment, at the removal of the Jumpers and at the end of the period of observation or retention. The Jumpers brought about a slight retrusion of the maxilla and markedly increased the mandibular prognathism. The maxillary incisors and molars were retruded, and the mandibular incisors and molars protruded. The median correction of the overjet was almost 5 mm and of the molar relationship 3 mm. The intrusive forces of the Jumper resulted in a transient intrusion of the maxillary molars and the mandibular incisors. After the period of retention and observation, the dento-alveolar effects had partially or totally relapsed. The remaining effect contributing most to the correction was the skeletal effect on the mandible, i.e. the increase in mandibular prognathism. The skeletal mandibular effect was the same in younger and older subjects. At the end of observation about 60 per cent of the overjet reduction and 75 per cent of the molar correction remained. The incidence of breakage of the Jumpers was 9 per cent.

PMID: 9699405 [PubMed - indexed for MEDLINE]

Dental changes in the mandible during initial Bass appliance therapy.

Eur J Orthod. 1998 Feb;20(1):17-23

Authors: Omblus J, Malmgren O

The aim of this study was to analyse movements of lower molars and incisors during 6 months of Bass appliance therapy and to evaluate the dental arch space attained. The sample consisted of 53 patients with severe Class II, division 1 malocclusions. The analyses were performed on lateral cephalograms and dental casts. Sixteen of the patients were followed for 6 months before treatment. Dental space in the lower jaw decreased 0.7 mm (n = 16) during the observation period and increased 1.8 mm (n = 53) during the 6 months of treatment. The molars moved posteriorly a total of 0.7 and tipped distally 2.4 degrees during treatment. The incisors moved anteriorly 0.3 mm and tipped mesially 0.5 degree.

PMID: 9558761 [PubMed - indexed for MEDLINE]

The effect of treatment with the Bass appliance on skeletal Class II malocclusions: a cephalometric investigation.

Eur J Orthod. 1997 Dec;19(6):691-702

Authors: Cura N, Sara&#xE7; M

The purpose of this investigation was to study the short-term effects of treatment with the Bass appliance by comparative evaluation of treated and untreated skeletal Class II malocclusions. The subjects consisted of forty-seven Class II, division 1 malocclusion cases. Twenty-seven (14 girls, 13 boys) were treated with the Bass appliance for an average of 6 months. The remaining 20 cases (6 girls, 14 boys) served as a control. At the end of the 6 month treatment period the statistically significant treatment changes could be summarized as follows: the sagittal skeletal relationship was improved as a result of favourable growth responses in both the maxilla and the mandible. The overjet was reduced and the molar relationship was corrected as a result of the extended skeletal changes. Distal movement of the upper dentition was evident, with unchanged inclination of the maxillary incisors. Both anterior and posterior facial heights were increased without changes in the inclinations of the palatal and mandibular planes. No significant dental movement was observed in the mandible.

PMID: 9458602 [PubMed - indexed for MEDLINE]

Aplasia of the mandibular condyle.

Eur J Orthod. 1997 Oct;19(5):483-9

Authors: Krogstad O

Aplasia of the mandibular condyle is extremely rare when not seen as a part of a syndrome. A case, apparently with no soft tissue aberrations, is described and a possible connection with the hemifacial microsomia syndrome is discussed.

PMID: 9386334 [PubMed - indexed for MEDLINE]

Removable quadhelices and transpalatal arches.

Br J Orthod. 1997 Aug;24(3):248-54

Authors: Young DR

PMID: 9313921 [PubMed - indexed for MEDLINE]

Long-term effects of Class II correction in Herbst and Bass therapy.

Eur J Orthod. 1997 Apr;19(2):185-93

Authors: Omblus J, Malmgren O, Pancherz H, H&#xE4;gg U, Hansen K

This study compared the initial and long-term skeletal and dental effects of Herbst and Bass appliance therapy for correction of Class II malocclusion. The sample comprised 18 pairs of boys matched for growth period at the time of therapy, with similar pre-treatment sagittal and vertical jaw base relationships. One boy in each pair was treated with the Herbst and the other with the Bass appliance. At follow-up, 15 boys of the Herbst group and 17 of the Bass group were available. Lateral cephalograms in centric occlusion taken before treatment, after 6 months of treatment and at the end of growth were analysed. After 6 months of treatment the Bass appliance seemed to have a greater effect on mandibular jaw base position. The correction of overjet and sagittal molar relationship was more complete in the Herbst patients due to dental changes. At follow-up varying effects both between and within pairs were observed. Overall, the skeletal and dental changes from start of treatment to end of growth were of the same magnitude. A restraining effect on the position of the maxilla was observed in both groups, somewhat more pronounced in the Bass sample. Both treatment methods are most useful in correction of severe Class II malocclusions. It was, however, difficult to find possible differences in treatment effects between the two methods due to great individual variations of growth.

PMID: 9183068 [PubMed - indexed for MEDLINE]

Mandibular growth during initial treatment with the Bass orthopaedic appliance in relation to age and growth periods.

Eur J Orthod. 1997 Feb;19(1):47-56

Authors: Omblus J, Malmgren O, H&#xE4;gg U

The aim of this study was to relate the initial orthopaedic effects of a Bass activator to age and growth periods at the time of therapy. The sample consisted of 54 boys with a severe Class II, division 1 malocclusion. The mean age at start of treatment was 11.4 years. Longitudinal records of standing height were used to assess the growth period during treatment. Three periods were established: pre-peak, peak and post-peak. The treatment period of each subject was assigned to one of these periods. Lateral cephalograms were available 6 months before treatment in 22 of the boys, and at the start of treatment and after 6 months in the whole sample. No significant growth changes were observed 6 months before treatment. During the initial 6 months of treatment a small restraining effect on the maxilla and a forward growth of the mandible was observed. A significant correlation between age and forward growth of the mandible during treatment was found in the pre-peak and peak groups. This indicates a great initial orthopaedic treatment effect in young boys in the pre-peak period and in boys with an early peak. In boys 10 years of age or older not having reached the peak period of growth, the treatment response was less pronounced.

PMID: 9071045 [PubMed - indexed for MEDLINE]

Patterns and prediction of orthodontic treatment course.

Eur J Orthod. 1996 Dec;18(6):645-54

Authors: Koch R, Bartsch A

Most attempts at the identification and prediction of treatment-related changes and outcome in orthodontics thus far have relied upon single biometric parameters instead of employing a systemic and ecological approach. The concept of facial harmony and the availability of sophisticated multivariate statistics offer new chances for a deeper understanding of the mechanisms of change. A longitudinal study has been conducted on approximately 500 youths aged 9-11 years, on average. Numerous parameters of cephalometric analysis, study casts, growth, treatment regimen and patient co-operation were assessed at the onset of treatment (T0) and after 1 year (T1) to determine treatment-related changes under therapy with removable appliances. Exploratory cluster analyses were based on five fundamental cephalometric parameters (SNA, SNB, ML-NSL, NL-NSL, NS-Ba) that establish an operational approach to harmonious facial relations (Segner and Hasund, 1991). As a first step, analyses were restricted to 281 Class II division 1 patients selected for good co-operation by an expert rating by the first author on a three-point rating scale. They all were treated with bionators either with anterior or posterior traction. Both subgroups were studied separately. Based on cluster analytic procedures, different patterns of change were identified for both types of appliance. A slight tendency toward harmonization of the initial skeletal relations was observed throughout all subgroups, with reactions being most obvious in the maxilla. The clusters produced for either appliance group were then screened for additional predictors of group membership by means of discriminant analysis. The findings are discussed in terms of the suitability of the methodological approach chosen.

PMID: 9009429 [PubMed - indexed for MEDLINE]

The reliability of the Frankfort Horizontal in roentgenographic cephalometry.

Eur J Orthod. 1996 Aug;18(4):367-72

Authors: Pancherz H, G&#xF6;kbuget K

This longitudinal investigation was undertaken to assess the reliability of the Frankfort Horizontal line (FH) when using either anatomical Porion (Po-a) or machine Porion (Po-m) as reference landmarks. Lateral head films (22 pairs) from subjects at the ages of 11 and 14 years were analysed twice. The results revealed that: (i) the registration error of Po-a was larger than of Po-m; (ii) for Po-a the registration error from the 11 year head films was approximately twice as large as from the 14 year head films; (iii) Po-m was, on average, located approximately 9 mm below and 2 mm anterior to Po-a; (iv) during the 3 years of observation, Po-m changed its position downward markedly more than Po-a; (v) due to the diverging location of machine Porion (Po-m) in relation to true Porion (Po-a) and the large change of Po-m with time, the FH was affected considerably. It was concluded that machine Porion was unsuitable for the construction of the FH. A misjudgement of the reference line may result in diagnostic misinterpretations and lead to false conclusions in longitudinal studies, e.g. when the outcome of a particular treatment procedure is evaluated.

PMID: 8921658 [PubMed - indexed for MEDLINE]

The hyaline zone and associated root surface changes in experimental orthodontics in rats: a light and scanning electron microscope study.

Eur J Orthod. 1996 Feb;18(1):11-8

Authors: Hellsing E, Hammarstrom L

Light and scanning electron microscopic (SEM) examinations were used to study the hyaline zone and associated root resorption after orthodontic treatment of the upper first molars of rats. The orthodontic treatment consisted of a fixed buccal expansion appliance with an initial force of 250 mN. The animals were divided into nine experimental groups with orthodontic treatment and one control group without orthodontic treatment. Three groups were sacrificed immediately after 1, 3, and 7 days of treatment, and six groups after 7 days of treatment followed by 1, 2, 3, 4, 5, and 6 weeks without treatment. A hyaline zone on the pressure side of the mesial root was identified at the light microscopic level of examination as well as the SEM examination as early as 1 day after the initiation of treatment. In the SEM it was found that on the roots of teeth studied in the first few days after initiation of treatment the hyaline tissue was so firmly attached to the root that it remained in place during the extraction and preparation procedures. After longer treatment periods these hyaline zones were lost at extraction or during the preparation for the SEM examination. The cementum surface under the hyaline zone had a smooth appearance suggesting that the surface had been modified by substances released from the hyaline zone. After 1 week of treatment, resorption in the cementum could be noticed. The resorption extended to the dentine as uncovered dentinal tubuli were found. Formation of reparative cementum started two weeks after treatment. Changes in the cementum surface as well as root resorption cavities could be seen for as long as 6 weeks after the cessation of orthodontic treatment.

PMID: 8746173 [PubMed - indexed for MEDLINE]

Effect of age on the rate of tooth movement in combination with local use of 1,25(OH)2D3 and mechanical force in the rat.

J Dent Res. 1992 Aug;71(8):1487-92

Authors: Takano-Yamamoto T, Kawakami M, Yamashiro T

The purpose of this study was to compare the amount and rate of tooth movement in young and mature rats administered 1,25(OH)2D3 simultaneous with application of mechanical force. In 30 seven-week-old and 30 28-week-old male Wistar rats, the right maxillary first molar was moved buccally with a fixed appliance. The appliances delivered forces ranging from 5 to 20 g. Twenty microL of 1,25(OH)2D3 (10(-10) and 10(-8) mol/L) was injected locally into the submucosal palatal area of the root bifurcation of the right first molar. The left side was injected with phosphate-buffered saline (PBS). In young rats receiving 10(-10) mol/L 1,25(OH)2D3 every three days, tooth movement significantly increased to 126% of that in PBS-injected control rats on day 20. In 1,25(OH)2D3-injected mature rats, tooth movement was stimulated markedly and increased with 10(-10) mol/L to 245% and with 10(-8) mol/L to 154% of the amount of tooth movement seen in the PBS-injected controls by the end of the experiment. PBS-injected rats had a plateau stage where tooth movement did not occur at all, while there was no such lag-time in the 1,25(OH)2D3-injected group which showed continuous tooth movement. The local injection of 1,25(OH)2D3 did not change serum calcium, phosphate, and alkaline phosphatase activity, and there were no apparent clinical or microscopic side-effects.

PMID: 1506515 [PubMed - indexed for MEDLINE]