Original Articles
Comparison of surgical and non-surgical methods of treating palatally impacted canines.
I – Periodontal and pulpal outcomes
Kwok K. Ling, Christopher T.C. Ho, Olena Kravchuk and Richard J. Olive
Comparison of surgical and non-surgical methods of treating palatally impacted canines.
II – Aesthetic outcomes
Kwok K. Ling, Christopher T.C. Ho, Olena Kravchuk and Richard J. Olive
Changes in interdental papillae heights following alignment of anterior teeth
Sanjivan Kandasamy, Mithran Goonewardene and Marc Tennant
The reliability of bonded lingual retainers
Robert Cerny
Sella turcica bridges in orthodontic and orthognathic surgery patients.
A retrospective cephalometric study
Hussam M. Abdel-Kader
Static frictional resistances of polycrystalline ceramic brackets with conventional slots, glazed slots and metal
slot inserts
Steven P. Jones and Gyaami Amoah
Lower intercanine width and gingival margin changes.
A retrospective study
Luciane Closs, Karine Squeff, Dirceu Raveli and Cassiano Rösing
Effect of Topacal C-5 on enamel adjacent to orthodontic brackets.
An in vitro study
Navid Karimi Nasab, Zahra Dalili Kajan and Azadeh Balalaie
The impact of orthodontic treatment on normative need.
A case-control study in Peru
Eduardo Bernabé, Socorro A. Borges-Yáñez and Carlos Flores-Mir
Review
Three-dimensional computed craniofacial tomography (3D-CT): potential uses and limitations
Hong Jin Chan, Michael Woods and Damien Stella
Case report
Treatment of skeletal 2 malocclusion using bone-plate anchorage.
A case report
Kallaya Kraikosol, Charunee Rattanayatikul, Keith Godfrey and T. Vattraraphoudet
Space closure using the Hycon device.
A case report
Viral A. Kachiwala, Anmol S. Kalha and J. Vigneshwaran
Abstracts
Comparison of surgical and non-surgical methods
of treating palatally impacted canines.
I - Periodontal and pulpal outcomes
Kwok K. Ling,* Christopher T. C. Ho,* Olena Kravchuk† and Richard J. Olive‡
School of Dentistry,* School of Land and Food Sciences,† University of Queensland and Specialist Practice,‡ Brisbane, Australia
Background: Inferior periodontal and pulpal outcomes may follow surgical exposure of palatally impacted maxillary canines.
Objectives: To compare the periodontal and pulpal health of palatally impacted maxillary canines following either surgical
exposure and assisted eruption (SE) or unassisted eruption following extraction of the overlying deciduous canine and
orthodontic creation of space in the arch (OT).
Methods: Twenty–eight subjects (OT group: N = 14; SE group: N = 14) with unilateral palatally impacted canines were
examined at least six months after orthodontic treatment. The gingival index score, plaque index score, pocket depth,
attachment loss, tenderness to percussion, pulpal responses to stimuli and radiographic assessment of changes in the pulpal
cavities and peri-radicular areas were collected on the maxillary canines, lateral incisors and premolars. The contralateral teeth
were used as controls.
Results: There were no significant differences in the plaque index scores, the gingival index scores or the periodontal outcomes
between the impacted canines in the two groups (SE and OT). More impacted canines than control canines had lost some
periodontal attachment in the SE group (p = 0.004). Although more lateral incisors, canines and premolars on the impacted
side had partially obliterated pulps than the corresponding teeth on the control side, the teeth in both groups had similar pulpal
responses (p = 0.064).
Conclusions: Natural eruption and conservative surgical exposure with orthodontic alignment have minor effects on the
periodontium. Impacted canines treated surgically and non-surgically had a higher prevalence of pulpal changes than the control
canines. Ultimately, the choice of treatment may depend on the clinical indications, the patient’s and the orthodontist’s preferences.
(Aust Orthod J 2007; 23: 1–7)
Received for publication: July 2006
Accepted: February 2007
Comparison of surgical and non-surgical methods
of treating palatally impacted canines.
II - Aesthetic outcomes
Kwok K. Ling,* Christopher T. C. Ho,* Olena Kravchuk† and Richard J. Olive‡
School of Dentistry,* School of Land and Food Sciences,† University of Queensland and Specialist practice,‡ Brisbane, Australia
Background: Palatally impacted maxillary canines may appear unsightly after treatment because of changes in position and
colour.
Aim: To determine if palatally impacted canines treated either by surgical exposure and orthodontic repositioning or by creation
of space in the arch and unassisted eruption have different aesthetic outcomes.
Methods: Twenty eight subjects with unilateral palatally impacted canines who had completed orthodontic treatment at least
6 months previously were recruited from three specialist practices. In 14 subjects the canines had been treated by surgical
exposure, orthodontic extrusion and repositioning in the arch (SE group) and in the remainder the deciduous canines were
extracted and excess space created in the arch for the canines to erupt naturally (OT group). The contralateral canines were
used as controls. The mean pretreatment ages of the subjects in the SE and OT groups were 13.5 (SD: 1.6) years and 13.5
(SD: 1.3) years respectively. The position and colour of the canines were assessed on post-treatment study models and 35 mm
slides using the American Board of Orthodontics Objective Grading System (ABO OGS) and subjective appraisal by two
orthodontists. Each subject used a semantic scale to rate the aesthetic outcome of treatment.
Results: Sixty four per cent of the treated canines in the SE group were significantly more ‘intruded’ than the treated canines
in the OT group (p = 0.004) and the control canines (p = 0.004). The ABO OGS grades of the canines in the SE and OT
groups were similar (p = 0.173). While the assessors detected a lack of labial root torque and gingival margin changes in
the canines in the SE group, the subjects in both groups were satisfied with the appearance of the canines post-treatment.
Conclusions: Palatally impacted canines treated by surgical exposure, extrusion and orthodontic treatment were more likely to
be displaced vertically (‘intruded’) after treatment than palatally impacted canines treated by extraction of the overlying
deciduous canines and creation of excess space in the arch. Small occlusal and aesthetic changes detected by the
orthodontists, but not the ABO OGS, did not appear to detract from the satisfaction of the subjects with the results of
orthodontic treatment.
(Aust Orthod J 2007; 23: 8–15)
Received for publication: July 2006
Accepted: February 2007
Changes in interdental papillae heights following
alignment of anterior teeth
Sanjivan Kandasamy,* Mithran Goonewardene* and Marc Tennant†
Dental School, The University of Western Australia* and the Centre for Rural and Remote Oral Health, The University of Western Australia,†
Perth, Australia
Background: Orthodontic alignment of overlapped incisors can reduce the apparent heights of the interdental papillae leading
to unsightly dark triangles or open gingival embrasures.
Aim: To determine if certain pretreatment contact point relationships between the maxillary anterior teeth were accompanied by
changes in the heights of the interdental papillae after orthodontic alignment.
Methods: Pre- and post-treatment intra-oral 35 mm slides, lateral cephalometric radiographs and study casts of 143 patients
(60 males, 83 females) between 13 and 16 years of age were used. The patients had diastamata closed, imbricated teeth
aligned and palatally or labially placed teeth repositioned. A sample of 25 patients (12 males, 13 females) between 13 and
16 years of age who had well-aligned anterior teeth at the start of treatment acted as a control group. All patients were
treated for approximately 18 months. The clinical crowns of the maxillary incisors and the heights of the interdental papilla
between the incisors were measured on projected images of the slides. The percentage increases or reductions in the heights of
the interdental papillae were compared.
Results: The heights of the interdental papillae increased following palatal movement of labially placed (p < 0.05) or
imbricated (p < 0.05) incisors and the intrusion of one incisor relative to an adjacent incisor (p < 0.01). The heights of the
interdental papillae reduced following labial movement of an imbricated (p < 0.05) or palatally placed (p < 0.05) incisor or
closure of a diastema (p < 0.01). Before treatment the midline papillae in the diastema subgroup were of similar length to the
midline papillae in the control group, but after treatment they were markedly shorter. The interdental papillae associated with
crowded or imbricated incisors were shorter than the interdental papillae in the control group before and after treatment.
Conclusions: Dark triangles are less likely to develop following palatal movement of labially placed or imbricated teeth and the
intrusion of one tooth relative to another. On the other hand, dark triangles are more likely to develop following labial movement
of imbricated or palatally placed incisors and closure of a diastema. Clinicians should be alert to the possibility of dark
triangles developing in the latter group, particularly in older patients.
(Aust Orthod J 2007; 23: 16–23)
Received for publication: July 2006
Accepted: January 2007
The reliability of bonded lingual retainers
Robert Cerny
Specialist practice, Newcastle, New South Wales, Australia
Background: Bonded lingual retainers have become increasingly popular, but there is little information on their long-term
reliability.
Objectives: The aims of this retrospective study were to investigate the reliability of bonded upper and lower lingual retainers
and the factors contributing to their failure.
Methods: The study group were 149 patients who returned between 2002 and 2005 with failed upper and/or lower fixed
lingual retainers. Approximately 230 patients were debonded each year and approximately 1150 patients were covered
annually by a 5-year guarantee of replacement or repair of failed retainers. The retainers were made from 0.018 inch round
stainless steel heat-treated orthodontic wire. The upper retainers had loops opposite the embrasures and the lower retainers had
loops between the lateral incisors and canines. The following details were recorded: teeth involved, patient gender, the likely
cause of any damage and the time taken for each repair.
Results: Between 35 and 40 patients required repair/replacement of their retainers each year. Multiple bond failures occurred
in approximately 9 per cent of these patients. Male patients had twice the fracture rate of female patients. Extra-oral trauma
was the most frequent cause of failure followed by intra-oral trauma, operator error and wire fracture. The central incisors in
both arches were the most frequent sites of failure. Single tooth repairs required approximately 12 minutes of the orthodontist’s
chair-side time.
Conclusions: Bonded lingual retainers are a reliable form of retention after orthodontic treatment.
(Aust Orthod J 2007; 23: 24–29)
Received for publication: January 2006
Accepted: January 2007
Sella turcica bridges in orthodontic and
orthognathic surgery patients.
A retrospective
cephalometric study
Hussam M. Abdel-Kader
Orthodontic Department, Faculty of Dental Medicine, Al-Azhar University, Cairo, Egypt
Objective: To investigate the prevalence of sella turcica bridges in patients accepted for conventional orthodontic treatment and
orthognathic surgery.
Methods: The pretreatment lateral cephalograms of 635 subjects scheduled for orthodontic treatment and 113 subjects
scheduled for orthognathic surgery were used. The number of subjects with complete sella bridges and the type of discrepancy
(Angle Class I, II, or III malocclusions, skeletal Class 2, 3 or bimaxillary protrusion) were recorded.
Results: Sella turcica bridges were found in 3.74 per cent of the total sample of 748 subjects. In the orthodontic group 3.21,
2.97 and 7.14 per cent of subjects in the Class I, II and III subgroups respectively had sella bridges. In the orthognathic
surgery group 2.86 and 10.71 per cent of the subjects in the Skeletal 2 and 3 subgroups respectively had sella bridges.
No subjects in the bimaxillary subgroup had sella bridges. In the orthodontic group 2.20 per cent of the female subjects and
1.10 per cent of the male subjects had sella bridges, while in the orthognathic surgery group 1.77 of the females and 4.42
per cent of the males had sella bridges.
Conclusions: Higher percentages of sella turcica bridges were found in subjects with Angle Class III and skeletal 3
discrepancies compared with subjects with Angle Class I, II, skeletal 2 or bimaxillary protrusion discrepancies.
(Aust Orthod J 2007; 23: 30–35)
Received for publication: June 2006
Accepted: January 2007
Static frictional resistances of polycrystalline
ceramic brackets with conventional slots,
glazed slots and metal slot inserts
Steven P. Jones* and K. Gyaami Amoah†
UCL Eastman Dental Institute for Oral Health Care Sciences, London, England* and University of Ghana Dental School, Accra, Ghana†
Aims: To compare the static frictional resistance of ceramic brackets with a conventional slot (Allure), a glazed slot (Mystique)
and a metal slot insert (Clarity).
Method: Twenty five brackets of each type, with slot size 0.022 x 0.028 inch and Roth prescription were tested by sliding
against straight lengths of 0.019 x 0.025 inch rectangular stainless steel wire. During the tests the brackets and wire were
lubricated with artificial saliva. Static frictional forces at three different simulated binding angulations (0, 5 and 10 degrees)
were measured for each type of bracket.
Results: At each of the angulations tested, the Clarity brackets produced the lowest static frictional resistance. At 0 degree
angulation (below the critical angle for binding) the Allure brackets produced the greatest friction. The difference in friction
between the Clarity and Mystique brackets was not statistically significant. As the angulations were increased to 5 degrees
the Allure brackets again produced the greatest frictional resistance, although this was not significantly higher than the Mystique
brackets. The Mystique brackets produced the greatest frictional resistance at 10 degrees, but again there was no statistical
difference from the Allure brackets.
Conclusions: A glazed slot ceramic bracket demonstrates low frictional resistance at non-binding angulations and compares
favourably with a metal slot ceramic bracket. Increasing angulations through 5 to 10 degrees of simulated binding results in
high levels of static frictional resistance such that the bracket behaves more like a conventional polycrystalline ceramic bracket.
(Aust Orthod J 2007; 23: 36–40)
Received for publication: October 2006
Accepted: February 2007
Lower intercanine width and gingival margin
changes.
A retrospective study
Luciane Closs,* Karine Squeff,† Dirceu Raveli* and Cassiano Rösing+
Araraquara School of Dentistry, Sao Paulo State University, Araraquara,* Specialist practice, Porto Alegre,† and Federal University of Rio Grande
do Sul, Porto Alegre,+ Brazil
Objective: To determine if changes in the lower intercanine widths during orthodontic treatment with fixed appliances result in
gingival margin changes around the lower canines and incisors.
Method: Pre- and post-treatment intra-oral photographs and orthodontic study models of 178 Caucasian adolescents (101
female, 77 male) were used. All subjects were treated with fixed appliances. The subjects had mean ages of 11.41 (SD:
1.83) years and 14.91 (SD: 1.78) years on their initial and final records respectively. The latter were taken 28 days or more
after the appliances had been removed. The inclusion criteria were: Angle Class I or Class II malocclusion (with or without
transverse and/or vertical discrepancies); nonextraction treatment; less than 4 mm crowding or spacing; fully erupted lower
incisors and good periodontal health. The intercanine widths and the positions of the gingival margins relative to the maximum
curvatures of the labial surfaces of the lower canines and incisors were measured with digital calipers.
Results: A significant association was found between unaltered intercanine widths and coronal migration of the gingival margins
(p = 0.045). There were no significant associations between either increased or reduced intercanine widths and changes in
the gingival margins.
Conclusions: Following orthodontic treatment coronal migration of the gingival margins around the lower incisors and canines is
more likely to be associated with an unaltered intercanine width.
(Aust Orthod J 2007; 23: 41–45)
Received for publication: April 2006
Accepted: February 2007
Effect of Topacal C-5 on enamel adjacent to
orthodontic brackets.
An in vitro study
Navid Karimi Nasab, Zahra Dalili Kajan and Azadeh Balalaie
Dental School, Guilan University of Medical Sciences, Rasht, Iran
Background: Enamel demineralisation leading to ‘white spots’ can occur during orthodontic treatment. Casein phosphopeptides
may reduce demineralisation during orthodontic treatment.
Aims: To determine if a casein phosphopeptide preparation, Topacal C-5 (Enamel Improving Cream, NSI Dental Pty Ltd,
Leighton, Hornsby, Australia), will inhibit demineralisation of enamel adjacent to orthodontic brackets.
Methods: Twenty-four pairs of human premolars from 24 subjects were used. One premolar in each pair was randomly
assigned to the control group and the contralateral premolar was assigned to the experimental group. A stainless steel
orthodontic bracket was bonded to the buccal surface of each tooth and a window of enamel (4 mm x 1 mm) left open to
acid attack. The teeth were cycled alternately through an artificial saliva medium (11 hours) and an acid medium (1 hour) for
31 days. Topacal C-5 was applied to the exposed enamel windows in the experimental group after immersion in the acid
medium. After 31 days the teeth were sectioned longitudinally and the depths of the enamel lesions measured by polarised
light microscopy.
Results: Significantly deeper demineralisation occurred in the control teeth not protected by Topacal C-5 and at sites close to the
brackets in both groups.
Conclusions: In this in vitro system, Topacal C-5 partially reduced the depth of enamel demineralisation compared with teeth
not covered with Topacal C-5. Topacal C-5 may reduce enamel demineralisation in patients with fixed orthodontic appliances.
(Aust Orthod J 2007; 23: 46–49)
Received for publication: July 2006
Accepted: March 2007
The impact of orthodontic treatment on normative
need.
A case-control study in Peru
Eduardo Bernabé,* Socorro A. Borges-Yáñez† and Carlos Flores-Mir+
Departamento de Odontología Social, Facultad de Estomatología, Universidad Peruana Cayetano Heredia, Lima, Perú,* División de Estudios de
Postgrado e Investigación, Facultad de Odontología, Universidad Nacional Autónoma de México, México D.F., México,† and Department of
Dentistry, University of Alberta, Edmonton, Canada+
Objective: To assess the impact of previously provided orthodontic treatment on the normative need in a sample of young adult
Peruvians.
Methods: Six hundred and thirty five freshmen, representative of all first year students registering in 2002 at a private university
in Lima, were randomly screened to obtain 63 cases and 126 controls. A case was defined as having a definite orthodontic
treatment need determined by the DAI and IOTN indices simultaneously. A control was defined as having no need of orthodontic
treatment based on both indices. Students were also asked if they had previously undergone any orthodontic treatment.
Binary logistic regression was used for the statistical analysis.
Results: Sex, age and socioeconomic status of the students were not statistically associated with normative orthodontic treatment
need (p = 0.258, 0.556 and ≥ 0.272 respectively). The percentage of students with a previous history of orthodontic treatment
was similar between the cases and the controls (14.3 per cent and 11.9 per cent respectively). There were no statistically
significant associations between the variables.
Conclusions: The impact of previously provided orthodontic treatment on the current normative need of young adults was limited.
Properly designed studies are required to assess the reasons for these findings.
(Aust Orthod J 2007; 23: 50–54)
Received for publication: September 2006
Accepted: April 2007
Three-dimensional computed craniofacial
tomography (3D-CT): potential uses and
limitations
Hong Jin Chan,* Michael Woods† and Damien Stella+
Private practice, Melbourne,* School of Dental Science, The University of Melbourne† and Department of Radiology,
Royal Melbourne Hospital,+ Melbourne, Australia
Aims: To determine the potential uses and limitations of 3D-CT craniofacial imaging in contemporary clinical practice.
Methods: The relevant historical and contemporary literature was reviewed.
Results: There would seem to be many potential uses for 3D-CT craniofacial imaging in clinical practice. Significant
limitations may, however, relate to the availability and cost of such imaging and the delivered radiation dose.
Conclusions: With continued research and development, the use of such 3D-CT craniofacial imaging techniques may become
appropriate for future orthodontic and clinical diagnostic applications.
(Aust Orthod J 2007; 23: 55–64)
Received for publication: November 2006
Accepted: March 2007
Treatment of skeletal 2 malocclusion using
bone-plate anchorage.
A case report
Kallaya Kraikosol,* Charunee Rattanayatikul,* Keith Godfrey,*and Theparith Vattraphudej †
Departments of Orthodontics* and Oral Surgery,† Faculty of Dentistry, Khon Kaen University, Khon Kaen, 40002 Thailand
Objective: To report the treatment of a severe Class II division 1 malocclusion using bone-plate anchorage.
Methods: A 12 year-old Thai girl presented with a skeletal 2, Class II division 1 malocclusion. Following extraction of the
maxillary first premolars and mandibular second premolars, the maxillary anterior teeth were retracted and the mandibular
posterior teeth moved mesially. A miniplate with screws, placed in each zygomatic buttress, was used as absolute anchorage
for coil springs to retract the maxillary anterior six teeth.
Results: After treatment, the patient presented with a normal overjet and overbite, a dental Class I relationship bilaterally and an
improved facial profile.
(Aust Orthod J 2007; 23: 65–71)
Received for publication: February 2006
Accepted: February 2007
Space closure using the Hycon device.
A case report
Viral A. Kachiwala, Anmol S. Kalha and J. Vigneshwaran
College of Dental Sciences, Davangere, Karnataka, India
Background: Space closure can be a difficult and uncomfortable procedure. Appliances able to be activated by the patient
may reduce the number of visits for adjustment.
Objective: To describe the closure of spaces with the Hycon device, an intra-oral screw that can be activated by the patient.
Method: Sliding mechanics were used to retract the upper and lower anterior teeth following extraction of the first premolars in
a patient with bimaxillary protrusion. The active force for retraction was derived from the Hycon device
activated twice a week by the patient.
Results: The rate of space closure achieved was of the order of 1.9 mm/month. The extraction spaces were closed by distal
movement of the anterior teeth and mesial movement of the posterior teeth.
Conclusion: The Hycon device proved to be an effective means of retracting the anterior teeth and protracting the posterior
teeth. Because the device can be activated by the patient fewer visits for adjustment may be required.
(Aust Orthod J 2007; 23: 72–75)
Received for publication: June 2006
Accepted: April 2007