Importance of occlusion aspects in the completion of orthodontic treatment.

Braz Dent J. 2007;18(1):78-82

Authors: Oltramari PV, Conti AC, Navarro Rde L, Almeida MR, Almeida-Pedrin RR, Ferreira FP

The purpose of this study was to address the therapeutic goals regarding the static and functional occlusion in the completion of orthodontic treatment. For such purpose, a study population comprising 20 female treated Class II malocclusion subjects with an initial mean age of 11 years underwent a two-phase treatment (orthopedics and orthodontics). The patients were diagnosed in centric relation and were treated according to the six keys for normal occlusion and functional occlusal parameters (centric relation, vertical dimension, lateral and anterior guidances, occlusal contacts and direction of forces applied on the teeth). After removal of fixed mechanics, retainers were installed and maintained for two years. Five years after orthodontic completion, the occlusal stability of the patients was evaluated regarding molar relationship and overjet, measured in dental casts. All subjects maintained the normal molar relationship and correct overjet achieved at the end of treatment, indicating a fair level of occlusal stability. The importance of the criteria of the ideal functional occlusion to ensure a better stability after completion orthodontic treatment will be discussed in detail in this paper. In addition, some clinical situations in which localized adjustments are indicated for occlusal refinement will be described.

PMID: 17639207 [PubMed - indexed for MEDLINE]

The reinforced removable retainer.

J Contemp Dent Pract. 2006 May 1;7(2):145-52

Authors: Al-Suliaman S, Hashim HA, Cordovez JL

The aim of this paper is to present a new type of orthodontic removable retainer, which is of great help to the orthodontist as well as to the patient. The procedures of fabrication are described. The Reinforced Removable Retainer (Triple "R" Retainer) is well tolerated, adaptable, and easy to fit and remove. Its main advantage is that it is not easy to break, less bulky, and very retentive.

PMID: 16685306 [PubMed - indexed for MEDLINE]

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

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

Authors: Baydaş B, Denizoglu S

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

PMID: 16491157 [PubMed - indexed for MEDLINE]

Clinical pearl: LingLock--the flossable fixed retainer.

J Orthod. 2005 Dec;32(4):241-3

Authors: Amundsen OC, Wisth PJ

The present article describes a new product for long-term retention of the lower dental arch. The LingLock is a fixed bonded retainer from canine to canine in the lower front made up of separate, but co-working retention elements in the ceramic material aluminium oxide (Al2O3). The LingLock retainer enables the patient to floss the teeth in a regular manner in the actual retention area.

PMID: 16333044 [PubMed - indexed for MEDLINE]

Assessment of open and incomplete bite correction by incisor overlap and optical density of polyvinyl siloxane bite registration.

Eur J Orthod. 2006 Apr;28(2):166-72

Authors: Shpack N, Einy S, Beni L, Vardimon AD

Open bite (OB) is a generalized term, which could incorporate subgroups that react differently to vertical correction. The objectives of the present study were to detect vertical treatment changes in incomplete bite (IB: inter-incisor overlap with no lower incisor contact with teeth or palate) and OB (no inter-incisor overlap) groups compared with a complete bite (CB: inter-incisor overlap with full lower incisor contact with teeth or palate) control group, to evaluate treatment response of the central and lateral incisors, and to study the vertico-sagittal interaction. Dental casts were taken at three time points, pre-treatment, post-treatment, and after one year of retention, from 54 Class II patients (22 males and 32 females with a mean age of 11 years 6 months) divided into three groups: CB (n = 21), IB (n = 18) and OB (n = 15). Measurements included incisor overlap (mm) and optical density (OD/mm2) of occlusal bite registration made of polyvinl siloxane. Both CB and IB groups demonstrated post-retention bite opening. However, bite opening in the CB group was three times greater than that in the IB group (e.g. lower lateral = -1.42 mm, 118 OD/mm2 versus -0.40 mm, 107 OD/mm2). Conversely, the OB group showed a significant (P < 0.001) bite closure (e.g. lower lateral = 1.30 mm, -377 OD/mm2). Overjet changes affected OD measurements, causing diversity in OD and millimetric measurements of the lateral incisors in the IB group. In conclusion, the OB group demonstrated a significant stable vertical correction; a post-treatment non-contact inter-incisor relationship was determined by a vertico-sagittal relapse; and full compensation of an IB was not possible.

PMID: 16267127 [PubMed - indexed for MEDLINE]

How to ... place a lower bonded retainer.

J Orthod. 2005 Sep;32(3):206-10

Authors: Shah AA, Sandler PJ, Murray AM

Post-orthodontic relapse of lower incisors is a common phenomenon. Sometimes a bonded retainer is fitted to prevent this relapse. In this article, we suggest a handy clinical technique of fitting a lower bonded retainer, which is convenient and easy to carry out.

PMID: 16170063 [PubMed - indexed for MEDLINE]

An approach to maintain orthodontic alignment of lower incisors without the use of retainers.

Eur J Orthod. 2005 Jun;27(3):209-14

Authors: Aasen TO, Espeland L

The purpose of this investigation was to examine the long-term stability of orthodontic alignment of lower incisors without the use of retainers. The study sample comprised 56 patients treated according to a protocol that included over-correction of rotated teeth at an early stage of treatment and systematic enamel reduction (stripping) of the approximal surfaces in the mandibular anterior region, both during treatment and follow-up. Care was also taken to maintain dental arch form and to avoid lateral expansion of the lower dental arch and proclination of the incisors. Dental study casts were obtained pre-treatment, at the end of treatment, and 3 years post-treatment. Alignment of the mandibular incisors was recorded using Little's irregularity index. The inter-canine distance and the sum of the mesio-distal widths of the mandibular incisors and canines were also measured.The total amount of enamel removed from the approximal surfaces of the lower anterior teeth ranged from 0.3 to 5.0 mm (mean 1.9 mm). The mean increase in irregularity index score of 0.6 from post-treatment to 3 years follow-up indicated good stability. In 45 per cent of the patients the change in score during this period was less than 0.5, indicating that the treatment approach presented may be considered an alternative strategy to placement of lower retainers to safeguard the stability of alignment of mandibular incisors.

PMID: 15947218 [PubMed - indexed for MEDLINE]

Degree of conversion of two lingual retainer adhesives cured with different light sources.

Eur J Orthod. 2005 Apr;27(2):173-9

Authors: Us&#xFC;mez S, Büyükyilmaz T, Karaman AI, Gündüz B

The aim of this study was to evaluate the degree of conversion (DC) of two lingual retainer adhesives, Transbond Lingual Retainer (TLR) and Light Cure Retainer (LCR), cured with a fast halogen light, a plasma arc light and a light-emitting diode (LED) at various curing times. A conventional halogen light served as the control.One hundred adhesive samples (five per group) were cured for 5, 10 or 15 seconds with an Optilux 501 (fast halogen light), for 3, 6 or 9 seconds with a Power Pac (plasma arc light), or for 10, 20 or 40 seconds with an Elipar Freelight (LED). Samples cured for 40 seconds with the conventional halogen lamp were used as the controls. Absorbance peaks were recorded using Fourier transform infrared (FT-IR) spectroscopy. DC values were calculated. Data were analysed using Kruskal-Wallis and Mann-Whitney U-tests.For the TLR, the highest DC values were achieved in 6 and 9 seconds with the plasma arc light. Curing with the fast halogen light for 15 seconds and with the LED for 40 seconds produced statistically similar DC values, but these were lower than those with the plasma arc light. All of these light exposures yielded a statistically significantly higher DC than 40 seconds of conventional halogen light curing. The highest DC value for the LCR was achieved in 15 seconds with the fast halogen light, then the plasma arc light curing for 6 seconds. These two combinations produced a statistically significantly higher DC when compared with the 40 seconds of conventional halogen light curing. The lowest DC for the LCR was achieved with 10 seconds of LED curing. The overall DC of the LCR was significantly higher than that of the TLR.The results suggest that a similar or higher DC than the control values could be achieved in 6-9 seconds by plasma arc curing, in 10-15 seconds by fast halogen curing or in 20 seconds by LED curing.

PMID: 15817625 [PubMed - indexed for MEDLINE]

Axiographic findings in patients undergoing orthodontic treatment with and without premolar extractions.

Eur J Orthod. 2004 Aug;26(4):427-33

Authors: Heiser W, Stainer M, Reichegger H, Niederwanger A, Kulmer S

Mechanical axiography was performed on 49 (37 female, 12 male) patients prior to orthodontic treatment, after removal of the fixed appliance, and at the end of retention. Twenty-five subjects (mean age 12.8 years) underwent orthodontic treatment without premolar extractions (group 1) and 24 subjects (mean age 13.5 years) with premolar extractions (group 2). The axiographic tracings of the protrusive movements were analysed using a digitizer and specially designed software. A statistically significant increase (P < 0.05) in the values for horizontal condylar inclination (HCI) was found for both groups over the entire observation period. Group 1 showed a higher increase (P < 0.05) between the beginning of treatment and removal of the brackets, and group 2 between bracket removal and the end of retention. At the end of retention, a similar increase in HCI values was found for both groups. Over the observation period, the frequency of pathological axiographic findings decreased, which seems to be a positive effect of orthodontic treatment.

PMID: 15366388 [PubMed - indexed for MEDLINE]

Skeletal and dental changes following surgically assisted rapid palatal expansion.

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

Authors: Byloff FK, Mossaz CF

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

PMID: 15366385 [PubMed - indexed for MEDLINE]

Changes in occlusion and maxillary dental arch dimensions in adults with treated unilateral complete cleft lip and palate: a follow-up study.

Eur J Orthod. 2004 Aug;26(4):385-90

Authors: Marcusson A, Paulin G

The purpose of this study was to evaluate the occlusion and maxillary dental arch dimensions in adults with repaired complete unilateral cleft lip and palate (UCLP) and to investigate the patterns of change in early adulthood. Study models from 39 patients (25 men, 14 women; mean age 24.7 years, range 20.2-29.3 years) with a diagnosis of complete UCLP taken at a follow-up examination were analysed and compared with the study models taken at baseline examination (mean age 19.1 years, range 16.0-20.6 years). Lip closure was carried out according to the Millard technique and palatal closure according to the Wardill-Kilner technique. All patients had received orthodontic treatment with fixed appliances. The patients were divided into three groups according to the type of retention in the upper arch: no retention (n = 15), retention with a bonded twisted retainer (n = 13), an onlay or fixed bridge (n = 11). Occlusion was evaluated according to a scoring system. The maxillary dental arch dimensions were measured with a video imaging system. There was a significant deterioration in the total occlusal score during the follow-up period and this was larger on the cleft than on the non-cleft side. There were no significant differences in the anterior scores. A comparison of the transversal and sagittal maxillary arch dimensions revealed significant differences in all measurements during the follow-up interval. The reduction was largest for the maxillary second premolar width, followed by the first molar width. The overjet differed significantly between the registrations. The occlusal score and the maxillary arch dimensions were reduced in all of the three subgroups, but there were no differences between the groups.

PMID: 15366382 [PubMed - indexed for MEDLINE]

Restoration of mechanical strength and morphological features of the periodontal ligament following orthodontic retention in the rat mandibular first molar.

Eur J Orthod. 2003 Apr;25(2):167-74

Authors: Fukui T, Yamane A, Komatsu K, Chiba M

Biomechanical properties and morphological features of the periodontal ligament (PDL) in the rat mandibular molars were examined during orthodontic retention. Seventy-three male rats of the Wistar strain, 8 weeks of age, were used for biomechanical analysis and six rats for morphological analysis. An elastic band was inserted between the mandibular first and second molars for 4 days; after removal of the elastic band the interdental space was filled with resin for 4 and 8 days. The maximum shear stress, tangent modulus, and failure strain energy density of the PDL of the first molar in the experimental animals decreased markedly following application of an orthodontic force. They increased rapidly and were restored completely to the control levels by the 8th day after retention. Light microscopy showed severe compression and extension of the PDL in the experimental animals on the 8th day after retention. Birefringent collagen fibre bundles running across the compressed and expanded PDL were observed, although they appeared to be thinner with less insertions into the alveolar bone or cementum in the experimental animals than in the controls. This suggests that the periodontal collagen fibres were partially reorganized and rearranged during retention. The reorganization and rearrangement of periodontal collagen fibres seemed to be partly related to the restoration of mechanical strength of the rat molar PDL during the 8 days of retention.

PMID: 12737215 [PubMed - indexed for MEDLINE]

Maxillary retention: is longer better?

Eur J Orthod. 2003 Feb;25(1):65-9

Authors: Destang DL, Kerr WJ

Two different maxillary retention regimes were compared to ascertain if differences in posttreatment relapse existed. The patient pool was derived from subjects being treated at two orthodontic departments in the west of Scotland. Group 1 (20 patients) followed a 6 month regime using removable upper Hawley retainers for a period of 3 months full time and 3 months nights only. Group 2 (18 patients) followed a 1 year regime of 6 months full time and 6 months nights only. The results revealed that maxillary incisor alignment, as determined by Little's irregularity index, had relapsed by an average of 50 per cent of the end of retention value 3 months out of retention in Group 1 but only 23 per cent in Group 2. Although the actual mean values for relapse were 0.77 and 0.23 mm, respectively, seven subjects in Group 1 showed relapse of more than 3 mm as compared with only one in Group 2. This suggests that retaining a case for 1 year rather than 6 months is clinically beneficial.

PMID: 12608725 [PubMed - indexed for MEDLINE]

Restoration and retention of maxillary anteriors with severe root resorption.

J Am Dent Assoc. 2002 Jan;133(1):67-71

Authors: Savage RR, Kokich VG

BACKGROUND: The authors describe the treatment of three patients who had severe apical root resorption of maxillary lateral incisors caused by ectopically erupting canines. Ectopically erupting canines derive from a normal path of eruption and may cause resorption of the adjacent teeth. CASE DESCRIPTION: The authors present the three cases of severe root resorption caused by ectopically erupting canines. They then discuss various prosthetic options; the indications, advantages and disadvantages of various treatment modalities; the long-term retention and esthetic concerns of the patients; and the inherent limitations of restorative treatment. CLINICAL IMPLICATIONS: Increased tooth mobility and long-term retention are significant concerns in cases of patients who have severe root resorption. Attaining stability with lingual splinting can cause esthetic problems. An interdisciplinary approach is necessary to provide optimal care for the patient.

PMID: 11811745 [PubMed - indexed for MEDLINE]

Maxillary unilateral molar distalization with sliding mechanics: a preliminary investigation.

Eur J Orthod. 2001 Oct;23(5):507-15

Authors: Keles A

Fifteen patients, eight males and seven females with a mean age of 13.32 years, were selected for unilateral molar distalization. Dentally, all presented with a unilateral Class II molar relationship. The subjects were all in the permanent dentition with second molars erupted and with a well aligned lower dental arch. For maxillary molar distalization a new intra-oral appliance was developed, the Keles Slider, which comprised two premolar and two molar bands. The anchorage unit was a Nance button with an anterior bite plane. From the palatal side, the point of distal force application was carried towards the level of centre of resistance of the maxillary first molar. A Ni-Ti coil spring was used and 200 g distal force was applied to the Class II first molar. Lateral cephalograms were taken and analysed before and 2 months after molar distalization. The Class II molars were distalized bodily, on average, 4.9 mm (P < 0.001). Mesial migration of the Class II first premolars was 1.3 mm (P < 0.05), incisor protrusion was 1.8 mm (P < 0.05) and incisor proclination 3.2 degrees (P < 0.05). The overbite was reduced by 3.1 mm (P < 0.001) and the overjet increased 2.1 mm (P < 0.01). For stabilization, the corrected Class II unilateral molar relationship was maintained with a Nance button for 2 months. The results show that this newly developed device achieved bodily distal molar movement with minimum anchorage loss.

PMID: 11668870 [PubMed - indexed for MEDLINE]

Rationalizing retention regimes.

J Orthod. 2001 Jun;28(2):180

Authors: Brenchley ML

PMID: 11395536 [PubMed - indexed for MEDLINE]

Breakage incidence with direct-bonded lingual retainers.

Br J Orthod. 1999 Sep;26(3):191-4

Authors: Lumsden KW, Saidler G, McColl JH

This study examined the effects of a number of patient and clinical variables on the breakage of bonded retainers, and consisted of a retrospective review of the survival of 200 bonded retainers. Data was collected from two clinical centres between November 1996 and February 1997. The subjects comprised 198 patients of both sexes divided into three age groups. Retainers at both centres were made in 018-inch co-axial wire with Relyabond and Helioprogress adhesives used at each respective centre. The effects on time to first breakage of adhesive, patient sex, and arch (upper/lower) were considered using Kaplan Meier survival graphs and in Log Rank Tests. Finally, a Cox Proportional Hazard Model was used to examine the joint effects of these factors and the patients' ages. Breakage over a 5-year period with Relyabond was 38.8 per cent upper, 22.1 per cent lower, and with Helioprogress 75 per cent upper and 23.2 per cent lower. Breakage appears to be unrelated to the materials used or to the age and sex of the patients. Upper retainers break more often than lowers (P = 0.016) and early breakage is more likely to occur at an adhesive pad than at a wire (9.6 versus 2.5 per cent within 6 months).

PMID: 10532157 [PubMed - indexed for MEDLINE]

A long-term evaluation of treated Class II division 2 malocclusions: a retrospective study model analysis.

Eur J Orthod. 1999 Aug;21(4):377-86

Authors: Canut JA, Arias S

Pre-treatment, end of treatment, and post-retention study models of 30 subjects with a Class II division 2 malocclusion were assessed, after a period of at least 3 years, in order to evaluate the long-term changes in occlusion, alignment, and arch dimensions. Molar relationship correction was found to be stable after retention. There were no variables which could be used to establish a prognosis of vertical stability. Over-correction of overbite was seen to relapse. Ten per cent of the cases showed unacceptable anterior maxillary irregularities after retention. Mandibular arch width and length usually showed a decrease after retention. An increase in lower intercanine width and arch length achieved by orthodontic treatment always relapsed. This relapse was associated with post-retention mandibular irregularity and crowding. Nine cases (30 per cent) showed an unacceptable degree of mandibular irregularity after retention. Pre-treatment crowding in the mandible showed a relationship with post-retention lower irregularity and crowding. There was a correlation between the number of years which had elapsed after retention, overbite relapse and post-retention mandibular irregularity.

PMID: 10502900 [PubMed - indexed for MEDLINE]

Intra-oral temperature variation over 24 hours.

Eur J Orthod. 1999 Jun;21(3):249-61

Authors: Moore RJ, Watts JT, Hood JA, Burritt DJ

This study aimed to investigate temperature variation at archwire sites adjacent to the maxillary right central incisor and first premolar, its correlation with ambient temperature, and the influence of inter-racial variation. Twenty young adult male subjects were randomly selected (13 Asian, seven Caucasian). Thermocouples were attached to the labial archwire component of custom-made orthodontic retainers at the two intra-oral sites. A third thermocouple measured ambient temperature. A data-logger recorded temperatures at 5-second intervals over a 24-hour period. Temperatures ranged from 5.6 to 58.5 degrees C at the incisor and from 7.9 to 54 degrees C at the premolar, with medians of 34.9 degrees C and 35.6 degrees C, respectively. Ambient temperature correlated poorly with the intra-oral temperatures. The Asian and Caucasian groups had significantly different temperature distributions. On average during the 24-hour period, temperatures at the incisor site were in the range of 33-37 degrees C for 79 per cent of the time, below it for 20 per cent, and above it for only 1 per cent of the time. Corresponding figures for the premolar site were 92, 6, and 2 per cent. At both archwire sites the most frequent temperatures were in the range of 35-36 degrees C. The data presented demonstrate that the temperature at sites on an archwire in situ varies considerably over a 24-hour period and that racial differences may exist. This information should be considered during the manufacture and use of temperature-sensitive orthodontic materials, in particular nickel-titanium archwires and springs.

PMID: 10407534 [PubMed - indexed for MEDLINE]

A comparison of sagittal and vertical effects between bonded rapid and slow maxillary expansion procedures.

Eur J Orthod. 1999 Apr;21(2):175-80

Authors: Akkaya S, Lorenzon S, U&#xE7;em TT

The purpose of this study was to determine the vertical and sagittal effects of bonded rapid maxillary expansion (RME), and bonded slow maxillary expansion (SME) procedures, and to compare these effects between the groups. Subjects with maxillary bilateral crossbites were selected and two treatment groups with 12 patients in each were constructed. The Hyrax screw in the RME treatment group and the spring of the Minne-Expander in the SME treatment group were embedded in the posterior bite planes, which had a thickness of 1 mm. At the end of active treatment these appliances were worn for retention for an additional 3 months. Lateral cephalometric radiographs were taken at the beginning and end of treatment, and at the end of the retention period. The maxilla showed anterior displacement in both groups. The mandible significantly rotated downward and backward only in the RME group. The inter-incisal angle and overjet increased in both groups. No significant differences were observed for the net changes between the two groups.

PMID: 10327741 [PubMed - indexed for MEDLINE]

The functional shift of the mandible in unilateral posterior crossbite and the adaptation of the temporomandibular joints: a pilot study.

Eur J Orthod. 1999 Apr;21(2):155-66

Authors: Nerder PH, Bakke M, Solow B

Changes in the functional shift of the mandibular midline and the condyles were studied during treatment of unilateral posterior crossbite in six children, aged 7-11 years. An expansion plate with covered occlusal surfaces was used as a reflex-releasing stabilizing splint during an initial diagnostic phase (I) in order to determine the structural (i.e. non-guided) position of the mandible. The same plate was used for expansion and retention (phase II), followed by a post-retention phase (III) without the appliance. Before and after each phase, the functional shift was determined kinesiographically and on transcranial radiographs by concurrent recordings with and without the splint. Transverse mandibular position was also recorded on cephalometric radiographs. Prior to phase I, the mandibular midline deviated more than 2 mm and, in occlusion (ICP), the condyles showed normally centred positions in the sagittal plane. With the splint, the condyle on the crossbite side was displaced 2.4 mm (P < 0.05) forwards compared with the ICP, while the position of the condyle on the non-crossbite side was unaltered. After phase III, the deviation of the midline had been eliminated. Sagittal condylar positions in the ICP still did not deviate from the normal, and the splint position was now obtained by symmetrical forward movement of both condyles (1.3 and 1.4 mm). These findings suggest that the TMJs adapted to displacements of the mandible by condylar growth or surface modelling of the fossa. The rest position remained directly caudal to the ICP during treatment. Thus, the splint position, rather than the rest position should be used to determine the therapeutic position of the mandible.

PMID: 10327739 [PubMed - indexed for MEDLINE]

Bone scintigraphy of human temporomandibular joints during Herbst treatment: a case report.

Eur J Orthod. 1998 Aug;20(4):369-74

Authors: Paulsen HU, Rab&#xF8;l A, Sørensen SS

Bone scintigraphy results were compared with changes shown on orthopantomographic radiographs in a patient with facial asymmetry, before, during, and after Herbst treatment, and followed up with control of growth activity in the temporomandibular joints (TMJs) after long-term retention. The present study showed that new bone formation (modelling) was initiated asymmetrically in TMJs during treatment. The results indicate that late development of right/left asymmetry in the occlusion can be corrected and normalized using the Herbst appliance therapy, stimulating a differentiated 'catch up' growth (modelling) in the TMJ with condyles. After treatment, original growth with asymmetric activity in the TMJ was re-established. This growth activity may re-establish the asymmetry in the sagittal occlusion and the face of the patient. It is therefore recommended that the occlusion should be maintained with an appliance which stabilizes the occlusion until cessation of the primary, endochondral growth.

PMID: 9753818 [PubMed - indexed for MEDLINE]

The periodontal-orthodontic interface: a simple solution to a difficult problem.

Br J Orthod. 1998 May;25(2):95-9

Authors: Johal AS, Lee RT

A technique which combines the use of a sectional fixed and removable appliance in periodontally compromised dentitions is described. The rationale behind treatment in these patients is discussed and the relative advantages over other techniques highlighted.

PMID: 9668991 [PubMed - indexed for MEDLINE]

The William Houston Gold Medal 1996.

Br J Orthod. 1998 May;25(2):85-93

Authors: Lawson RB

PMID: 9668990 [PubMed - indexed for MEDLINE]

A cautionary tale of simplified retention.

Br J Orthod. 1997 Nov;24(4):345-6

Authors: Remmelink HJ

PMID: 9459040 [PubMed - indexed for MEDLINE]

Phosphor-stimulated computed cephalometry: reliability of landmark identification.

Br J Orthod. 1997 Nov;24(4):301-8

Authors: Lim KF, Foong KW

The aim of this randomized, controlled, prospective study was to determine the reliability of computed lateral cephalometry (Fuji Medical Systems, Tokyo, Japan) in terms of landmark identification compared to conventional lateral cephalometry (CAWO, Schrobenhausen, Germany). To assess the reliability of landmark identification on lateral cephalographs, 20 computed images, taken at 30 per cent reduced radiation (70 kV, 15 mA, 0.35 s) were compared to 20 conventional images (70 kV, 15 mA, 0.5 s). The 40 lateral cephalographs were taken from 20 orthodontic patients at immediate post-treatment and 1 year after retention. The order and type of imaging was randomized. Five orthodontists identified eight skeletal, four dental and five soft tissue landmarks on each of the 40 films. The error of identification was analysed in the XY Cartesian co-ordinate following digitization. Skeletal landmarks exhibited characteristic dispersion with respect to the Cartesian co-ordinates. Root apices were more variable than crown tips. Soft tissue landmarks were more consistent in the X co-ordinate. Two-way ANOVA shows that there is no significant difference between the two imaging systems in both co-ordinates (P > 0.05). Moreover, the differences are generally small (< 0.5 mm), and are unlikely to be of clinical significance. Most of the variables attained statistical power of at least 0.8 in the X-co-ordinate while only the dental landmarks achieved statistical power of at least 0.78 in the Y-co-ordinate. Based on the results of the study: (1) computed lateral cephalographs can be taken at 30 per cent radiation reduction, compared to conventional lateral cephalograph; (2) each anatomical landmark exhibits its characteristic dispersion of error in both the Cartesian co-ordinates; (3) there is no trend between the two imaging systems, with equivocal result, and none of the landmarks attained statistical significance when both raters and imaging systems are considered as factorial variables; (4) the random error of raters in landmark identification after replicate tracing was highlighted and needs to be taken into consideration in all studies involving landmark identification.

PMID: 9459029 [PubMed - indexed for MEDLINE]

The B.S.S.O. M. Orth. Prize of the Royal College of Surgeons of England 1996.

Br J Orthod. 1997 Nov;24(4):285-91

Authors: Spencer RJ

PMID: 9459026 [PubMed - indexed for MEDLINE]

A 3-year follow-up study of various types of orthodontic canine-to-canine retainers.

Eur J Orthod. 1997 Oct;19(5):501-9

Authors: Artun J, Spadafora AT, Shapiro PA

The present study was performed to test the tendency for plaque and calculus build-up along the wire of different types of bonded orthodontic canine-to-canine retainers, whether the presence of such retainers causes any damage to the teeth involved, the failure rate of the retainers, and any changes in incisor alignment during a 3-year period of retention. The four test groups received either retainers made of thick plain wire bonded only to the canines (n = 11); thick spiral wire bonded only to the canines (n = 13); thin, flexible spiral wire bonded to each tooth (n = 11); or removable retainers (n = 14). Accumulation of plaque and calculus along the gingival margin, gingival inflammation and probing attachment level were scored in lingual areas from canine to canine at the time of fixed appliance removal and again 3 years after retainer insertion. Incisor irregularity was measured on plaster models made at the same time periods. Accumulation of plaque and calculus and development of caries along the wire were scored at follow-up. Retainer failures were recorded whenever they occurred. The results revealed no intergroup differences in changes between baseline and follow-up examinations or status along the retainer wire for any of the variables. Gingival inflammation and plaque accumulation were scored less frequently after 3 years in retention than at the time of debonding. No signs of caries were seen adjacent to the wire. Failures were observed of one, four and three of the fixed retainer types, respectively. These patients showed a greater increase in incisor irregularity than the other patients.

PMID: 9386336 [PubMed - indexed for MEDLINE]

Re: The use of pressure formed retainers in cases of hypodontia.

Br J Orthod. 1997 Aug;24(3):257-8

Authors: Peden M, McSherry P, Burden D

PMID: 9313922 [PubMed - indexed for MEDLINE]

Evaluation of treatment and post-treatment changes by the PAR Index.

Eur J Orthod. 1997 Jun;19(3):279-88

Authors: Birkeland K, Furevik J, B&#xF8;e OE, Wisth PJ

To assess the outcome of orthodontic treatment, 224 cases treated in a postgraduate clinic were evaluated. Pre-treatment (T1), post-treatment (T2) and 5-year follow-up (T3) study casts were assessed by the Peer Assessment Rating (PAR) Index. The influence of various factors upon treatment and long-term outcome was analysed. According to the PAR Index, orthodontic treatment reduced the malocclusions on average by 76.7 per cent, and at follow-up the reduction was 63.8 per cent. Follow-up stability was good for 76.3 per cent of the cases. Some cases (4.0 per cent) even improved, while moderate to severe post-treatment relapse occurred in 19.7 per cent of the cases. Orthodontic treatment changed Angle Class I, II and III malocclusions to near ideal occlusion (PAR scores 4.4-6.8). No long-term interaction between the groups was discovered. Sex and extraction/non-extraction treatments did not significantly affect the results. The initial PAR score accounted for 77.8 per cent of the variation in treatment PAR score change (T1-T2), and for 61.8 per cent of the variation of long-term PAR score change (T1-T3). Age at treatment start accounted significantly for the variability of treatment changes (P < 0.001). The PAR score at the end of treatment had some explanatory importance (R2 = 0.099) for the long-term (T1-T3) result. However, PAR score changes in the follow-up period were difficult to predict.

PMID: 9239958 [PubMed - indexed for MEDLINE]

The 'hands free' method for the accurate placement and bonding of a multistrand wire splint.

Br J Orthod. 1997 May;24(2):177

Authors: Becker A

PMID: 9218119 [PubMed - indexed for MEDLINE]

A cautionary tale of simplified retention.

Br J Orthod. 1997 May;24(2):113-5

Authors: Brenchley ML

Attention is drawn to a possible serious unwanted sequela of a simplified bonded retainer. It is illustrated by three brief case histories.

PMID: 9218108 [PubMed - indexed for MEDLINE]