Original Articles
Accuracy and validity of space analysis and irregularity index measurements using digital models
Roy W. Goonewardene, Mithran S. Goonewardene, John M. Razza and Kevin Murray
Are ratings of dentofacial attractiveness influenced by dentofacial midline discrepancies?
Tarulatha R. Shyagali, B. Chandralekha, Deepak P. Bhayya, Santhosh Kumar and Goutham
Balasubramanyam
Comparison of methods used to correct a lingually tilted mandibular molar: 3-D analysis using the finite
element method (FEM)
Allahyar Geramy and Hannaneh Ghadirian
Comparison of active self-ligating brackets and conventional pre-adjusted brackets
Robert Hamilton, Mithran S. Goonewardene and Kevin Murray
The effects of bracket removal on enamel
Farzin Heravi, Roozbeh Rashed and Leila Raziee
Mechanomyogram and electromyogram analyses during isometric contraction in human masseter muscle
Hideki Ioi, Makoto Kawakatsu, Shunsuke Nakata, Akihiko Nakasima and Amy L. Counts
The effects of systemic stress on orthodontic tooth movement
Gustavo Hauber Gameiro, Darcy Flávio Nouer, Joa~o Sarmento Pereira-Neto, Marília Bertoldo Urtado,
Pedro Duarte Novaes, Margaret de Castro and Maria Cecília Ferraz Arruda Veiga
Tooth size discrepancies in female patients with palatally impacted canines
Kazem Al-Nimri, Imad Adwan, Tareq Gharaibeh and Abdalla M. Hazza’a
Clinical effects associated with miniscrews used as orthodontic anchorage
Sulainee Kokitsawat, Montien Manosudprasit, Keith Godfrey and Charunee Chatchaiwiwattana
Review
Risk factors and indications of orthodontic temporary anchorage devices: a literature review
Sofie Hoste, Marjolein Vercruyssen, Marc Quirynen and Guy Willems
Case report
Assisted eruption of impacted teeth into an alveolar bone graft in a patient with cleft lip and palate
Chonthicha Peamkaroonrath, Montien Manosudprasit and Keith Godfrey
Treatment of severe bimaxillary protrusion with miniscrew anchorage: treatment and complications
Hiroshi Mimura
Abstracts
Accuracy and validity of space analysis and
irregularity index measurements using
digital models
Roy W. Goonewardene,* Mithran S. Goonewardene,* John M. Razza*
and Kevin Murray†
Dental School* and School of Mathematics and Statistics,† The University of Western Australia, Nedlands, Western Australia
Background: Digital copies of study models may avoid the storage and retrieval issues of plaster study models, but
measurements made on digital models may not be as accurate as measurements made on traditional study models.
Aim: To determine the reliability and validity of tooth size–arch length discrepancies (TALD), irregularity indices and arch lengths
(four- and six-segment analyses) measured directly on study models with digital calipers with the same measurements measured
on digital copies of the study models with proprietary software.
Methods: The irregularity indices and TALDs (four- and six-segments) were measured on 50 sets of pretreatment plaster models.
The plaster models were measured using manual calipers with a digital readout. The models were then couriered to OrthoCAD
and digital copies emailed to the authors. The digital models were measured with the proprietary software provided with the
digital models. Repeat measurements of the TALDs and the irregularity indices were subjected to intraclass correlations (ICC) to
assess the reliability. The least squares means of variation was used to assess validity and the impact of measuring arch length
(four- and six-segments) on the digital models, and the implications on the TALDs.
Results: There were high correlations (ICC) ranging from 98.6–99.9 per cent for both the irregularity indices and the TALDs.
The choice of manual over computer and four-segment over six-segment analysis had a significant effect when measuring lower
arch lengths (p < 0.05), but they had no effect on the upper arch findings.
Conclusions: Reliable measurements of the irregularity index and the TALD can be made on digital models. Computer
measurements of TALDs on digital models were more consistent than manual measurements of TALDs on plaster models.
Six-segment analyses of lower arch lengths on digital and plaster models gave more consistent findings than the four-segment
analyses.
(Aust Orthod J 2008; 24: 83–90)
Received for publication: March 2007
Accepted: June 2008
Roy Goonewardene: gooner02@student.uwa.edu.au
Mithran Goonewardene: mithran.goonewardene@uwa.edu.au
John Razza: jmrazza@ohcwa.uwa.edu.au
Kevin Murray: kev@maths.uwa.edu.au
Are ratings of dentofacial attractiveness influenced
by dentofacial midline discrepancies?
Tarulatha R. Shyagali,* B. Chandralekha,† Deepak P. Bhayya,± Santhosh Kumar+ and
Goutham Balasubramanyam+
Departments of Orthodontics and Dentofacial Orthopedics,* Pediatric and Preventive Dentistry,± and Preventive and Community Dentistry,+
Darshan Dental College and Hospital, Loyara, Udaipur, and the Department of Orthodontics and Dentofacial Orthopedics, NSVK Dental
College, Bangalore,† India
Aims: To assess the attractiveness of dentofacial midline discrepancies during smiling, and to determine if the ratings were
influenced by the gender of the judges.
Methods: Twenty non-dental undergraduate students (10 males, mean age: 33.5 years; 10 females, mean age: 31.2 years)
and 20 orthodontists (10 males, mean age: 36.6 years; 10 females, mean age: 34.3 years) assessed frontal photographs of
the same smiling adult female with coincident midlines, and images of the same person with the upper dental midline shifted
2 mm and 4 mm to the right and left of the facial midline. The judges scored the attractiveness of the smile using 5-point scale.
Results: Both the students and the orthodontists considered that the images were less attractive as the dentofacial midline
discrepancy increased. More orthodontists than undergraduate students, and more female orthodontists than male orthodontists,
considered a 4 mm discrepancy between the dental and facial midlines as unattractive.
Conclusion: Dental to facial midline discrepancies reduce dentofacial attractiveness. Discrepancies of 2 mm or more are likely
to be noticed by both orthodontists and non-dental university students. Orthodontic treatment objectives should include correction
of the dental midline discrepancies to within 2 mm of the facial midline.
(Aust Orthod J 2008; 24: 91–95)
Received for publication: March 2008
Accepted: September 2008
Tarulatha R. Shyagali: drdeepu@rediff.com
B. Chandralekha: santosh_dentist@yahoo.com
Deepak P. Bhayya: drdeepu20@yahoo.com
Santhosh Kumar: santosh.dentist@gmail.com
Goutham Balasubramanyam: goutham_dentist@yahoo.com
Comparison of methods used to correct a lingually
tilted mandibular molar: 3-D analysis using the
finite element method (FEM)
Allahyar Geramy and Hannaneh Ghadirian
Department of Orthodontics, Dental Research Centre, Tehran University of Medical Sciences, Tehran, Iran
Background: Methods used to upright lingually tilted mandibular molars frequently result in extrusion and unwanted rotations.
Aim: To use the finite element method (FEM) to compare three springs designed to upright a lingually tilted mandibular first
molar.
Methods: A 3-D computer model of a lingually tilted mandibular first molar was designed. The FEM was used to compare
movement of the molar during uprighting with either a single horizontal helix, an open vertical loop, or a new spring with two
vertical helices wound around and perpendicular to the long axis of the archwire. Each spring was assumed to be part of a
continuous 0.016 x 0.022 inch stainless steel archwire, and each spring was placed mesial to the buccal tube on the first
molar.
Results: From the mesial perspective, all designs moved the crown of the lingually tilted molar buccally and the root apex
lingually. From the occlusal perspective: the horizontal helix uprighted the molar with a disto-buccal rotation; the open vertical
loop uprighted the molar with a mesio-buccal rotation; and the new design uprighted the lingually tilted molar around a
mesio-distal axis.
Conclusion: Using FEM, the most suitable design was a double helix formed around and perpendicular to the long axis of the
archwire and sited mesial to the tilted molar. It was the only spring to upright the lingually tilted molar without an unwanted
rotation.
(Aust Orthod J 2008; 24: 96–101)
Received for publication: February 2008
Accepted: June 2008
Allahyar Geramy: gueramya@yahoo.com
Hannaneh Ghadirian: dds1358@yahoo.com
Comparison of active self-ligating brackets and
conventional pre-adjusted brackets
Robert Hamilton,* Mithran S. Goonewardene* and Kevin Murray†
Dental School,* and the School of Mathematics and Statistics, † The University of Western Australia, Australia
Background: Active self-ligating brackets may be more efficient than conventional pre-adjusted brackets.
Aims: To determine if self-ligating brackets are more efficient than conventional pre-adjusted brackets when used in a specialist
practice setting.
Methods: Seven hundred and sixty two patients, consecutively treated with fixed appliances, were evaluated retrospectively. All
patients were treated by one orthodontist in a private orthodontic practice. Three hundred and eighty three patients were treated
using a conventional pre-adjusted bracket system and 379 patients were treated with active self-ligating brackets. The total
treatment time, number of appointments, appointment intervals, number of bracket breakages and number of unscheduled emergency
appointments were recorded. Pretreatment characteristics identified by the ICON were related to these variables.
Results: The average treatment duration was 15.7 months (Range: 4.1–40.5 months; SD: 5.6 months). Comparable amounts
of time were spent in rectangular and round archwires by both appliances. Overall, there was no statistically significant
difference between the durations of treatment with active self-ligating brackets and conventional pre-adjusted brackets.
The number of debonded brackets and other emergency visits was significantly higher in patients treated with active
self-ligating brackets. The treatment characteristics associated with prolonged treatment were: extraction of teeth, a Class II
molar relationship and the degree of maxillary crowding or spacing.
Conclusions: Active self-ligating brackets appear to offer no measurable advantages in orthodontic treatment time, number of
treatment visits and time spent in initial alignment over conventional pre-adjusted orthodontic brackets.
(Aust Orthod J 2008; 24: 102–109)
Received for publication: June 2008
Accepted: July 2008
The effects of bracket removal on enamel
Farzin Heravi,*Roozbeh Rashed* and Leila Raziee†
Department of Orthodontics and Dental Research Center, School of Dentistry, Mashhad University of Medical Sciences, Mashhad* and the
Department of Pediatric Dentistry, School of Dentistry, Yazd University of Medical Sciences, Yazd,† Iran
Background: Enamel cracks, which may develop during debonding orthodontic brackets, may jeopardise the integrity of the
enamel and detract from the appearance of the teeth.
Aim: To compare the adhesive remnant scores (ARI), the number, lengths and directions of enamel cracks before bonding and
after debonding metal orthodontic brackets with three different methods.
Methods: Metal brackets were bonded with a self-curing orthodontic adhesive to the buccal surfaces of 75 recently extracted
upper and lower premolars. The teeth were randomly divided into three groups, and the brackets removed either with a sidecutter,
a single-blade bracket remover or a two-blade bracket remover. The number, directions and lengths of the enamel cracks
before bonding and after debonding were compared. The number of ‘pronounced’ cracks (i.e. cracks that could be identified
with the naked eye) and the ARI scores in each group were also compared.
Results: After debonding, the number of enamel cracks and pronounced cracks, and the lengths of the enamel cracks increased
in all groups (p < 0.001). There were no statistically significant differences between the groups. The ARI scores and the
direction of propagation of the enamel cracks were not influenced by the debonding method used (p = 0.73).
Conclusions: Concerns about the enamel damage caused by the three methods of debonding justify caution. Despite
widespread use of these methods, it would be sensible to search for methods that result in less enamel damage.
(Aust Orthod J 2008; 24: 110–115)
Received for publication: March 2008
Accepted: August 2008
Farzin Heravi: heravif@mums.ac.ir
Roozbeh Rashed: rashedr831@mums.ac.ir
Leila Raziee: leilaraziee@yahoo.com
Mechanomyogram and electromyogram analyses
during isometric contraction in human masseter
muscle
Hideki Ioi,* Makoto Kawakatsu,† Shunsuke Nakata,* Akihiko Nakasima* and
Amy L. Counts+
Department of Orthodontics, Faculty of Dentistry, Kyushu University, Fukuoka,* Private practice, Kawakatsu Orthodontic Clinic,† Fukuoka,
Japan and Dental School of Orthodontics, Jacksonville University, Jacksonville, Florida, United States of America+
Aims: To investigate the relationship between mechanomyogram (MMG), electromyogram (EMG) and bite force during
isometric contraction of the human masseter muscle.
Methods: Data were obtained from 16 healthy Japanese males (Mean age: 25.6 ± 2.3 years). The measuring device for
MMG consisted of an amorphous sensor and a small magnet. The bite force, MMG and EMG signals were recorded
simultaneously during isometric contraction of the masseter muscle. The subjects were instructed to perform 0, 5, 10, 20, 30,
40, 50, and 60% maximal voluntary contractions (MVC) for 20 seconds. The average rectified value (ARV) for MMG and
EMG were calculated from 1 to 5 second samples. The median frequency of the power spectrum (MFPS) for MMG and EMG
were determined with the use of a fast Fourier transformation algorithm.
Results: The mean ARV for MMG increased up to 20% MVC and then gradually decreased at the higher force levels. The
mean ARV for EMG increased with bite force in a monotonic fashion. The mean MFPS for MMG clearly increased up to 10%
MVC and then gradually increased. On the other hand, the mean MFPS for EMG clearly increased up to 10% MVC, but then
gradually decreased with bite force.
Conclusion: These findings suggest that the MMG analysis combined with the EMG may be a more useful method for
evaluating the status of the masseter muscle.
(Aust Orthod J 2008; 24: 116–120)
Received for publication: June 2008
Accepted: October 2008
The effects of systemic stress on orthodontic
tooth movement
Gustavo Hauber Gameiro,* Darcy Flávio Nouer,* João Sarmento Pereira-Neto,*
Marília Bertoldo Urtado,† Pedro Duarte Novaes,+ Margaret de Castro± and Maria
Cecília Ferraz Arruda Veiga†
Division of Orthodontics,* Oral Physiology† and Histology,+ Piracicaba Dental School, State University of Campinas – UNICAMP, Piracicaba
and the Division of Endocrinology,± Department of Internal Medicine, Ribeirão Preto Medicine School, University of São Paulo – USP, Ribeirão
Preto, Brazil
Objectives: To determine if systemic stress affects the biological reactions occurring during orthodontic tooth movement.
Methods: Four groups of male 10 week-old Wistar rats were used. Group A animals (N=10) were restrained for one hour per
day for 40 days; Group B animals (N=10) were restrained for one hour per day for three days; Group C (N=10) and Group
D (N=8) animals were unrestrained. The upper left first molars in the rats in Groups A (long-term stress), B (short-term stress) and
C (control) were moved mesially during the last 14 days of the experiment. The animals in Group D (N=8) were used for body
weight and hormonal dosage comparisons only. They were not subjected to any stress and did not have appliances fitted.
All animals were killed at 18 weeks of age and blood collected for measurement of plasma corticosterone. Tooth movement
was measured with an electronic caliper. The right and left hemi-maxillae of five rats from each group were removed and the
number of tartrate-resistant acid phosphatase (TRAP) positive cells, defined as osteoclasts, adjacent to the mesial roots of the
upper first molars counted. The contralateral side in each animal served as the control (split-mouth design).
Results: Corticosterone levels were significantly higher in the stressed groups (Groups A and B) than in the control group (Group
C). Tooth movement was significantly greater in Group A (long-term stress) compared with Group B (short-term stress) and
Group C (control), which did not differ from each other. There were significantly more osteoclasts in the long-term stress group
than in the short-term stress and control groups.
Conclusion: Persistent systemic stress increases bone resorption during orthodontic tooth movement. Systemic stress may affect
the rate of tooth movement during orthodontic treatment.
(Aust Orthod J 2008; 24: 121–128)
Received for publication: May 2008
Accepted: October 2008
Gustavo Hauber Gameiro: gustavo@gameiro.pro.br
Darcy Flavio Nouer: nouer@fop.unicamp.br
Joao Sarmento Pereira-Neto: sarmento@fop.unicamp.br
Marilia Bertoldo Urtado: mariliabertoldo@gmail.com
Pedro Duarte Novaes: novaes@fop.unicamp.br
Margaret de Castro: castrom@fmrp.usp.br
Maria Cecilia Ferraz Arruda Veiga: cveiga@fop.unicamp.br
Tooth size discrepancies in female patients with
palatally impacted canines
Kazem Al-Nimri, Imad Adwan, Tareq Gharaibeh and Abdalla M. Hazza'a
School of Dentistry, Jordan University of Science and Technology, Jordan
Background: Small upper lateral incisors in patients with palatally impacted canines may contribute to inter-arch tooth size
discrepancies.
Aim: To compare the Bolton ratios in female patients with and without unilateral palatally impacted canines.
Methods: The pretreatment dental casts of 30 female patients with unilateral palatally impacted canines (Impaction group) and
30 female patients without palatally impacted canines (Control group) were used. The latter were matched for age and incisor
malocclusion with the Impaction group. The anterior and overall Bolton ratios were calculated for each group.
Results: Although the total width of the upper anterior teeth in the Impaction group was significantly smaller than the total width
of the upper anterior teeth in the Control group (p = 0.029), there was no significant difference between the mesio-distal
widths of the lower anterior teeth in the two groups. Furthermore, there were no significant group differences in either the mean
anterior Bolton ratio (p = 0.156) or the overall Bolton ratio (p = 0.652).
Conclusion: Females patients with palatally impacted canines may not have more inter-arch tooth size discrepancies than
female patients without palatally impacted canines.
(Aust Orthod J 2008; 24: 129–133)
Received for publication: February 2008
Accepted: October 2008
Clinical effects associated with miniscrews used as
orthodontic anchorage
Sulainee Kokitsawat, Montien Manosudprasit, Keith Godfrey and Charunee
Chatchaiwiwattana
Department of Orthodontics, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
Aims: To measure the clinical effects associated with miniscrew anchorage used to retract the upper anterior teeth, specifically
the positional changes associated with the miniscrews, the upper anterior teeth and the first upper molars.
Methods: This clinical trial included 13 patients. After orthodontic alignment, miniscrews were inserted in the maxillary
zygomatic buttresses as anchorage for en masse retraction of the upper anterior teeth. Following premolar extractions, nickeltitanium
closed coil springs, stretched between the miniscrews and upper archwire, were used for retraction. Three-dimensional
changes in the upper anterior teeth, the upper first molars and the heads of the miniscrews were measured on study models
taken before a 300 g force was applied and seven months later, or when retraction was completed if less than seven months.
Results: The mean duration of retraction was 5.23 months (SD: 1.74 months) with a range of three to seven months. The mean
amount of anterior retraction was 3.82 ± 1.64 mm (Range: 0.77-7.07 mm). Average movements of the miniscrew heads on
the right side were 0.44 mm buccally, 0.38 mm forward and 0.54 mm downward, and on the left side 0.06 mm buccally,
0.41 mm forward and 0.50 mm downward. During the study period the right and left upper first molars moved mesially 0.70± 0.46 mm (Range: 0.01-2.3 mm) and 0.76 ± 0.47 mm (Range: 0.1-2.61 mm) respectively, although no force was applied
to them.
Conclusion: Miniscrews provide satisfactory anchorage for retraction of the upper anterior segment, but do not remain
absolutely stationary under orthodontic loads. Because of coincidental mesial movement of the upper molars, there must be
sufficient clearance mesial to the molars to avoid the molar roots contacting the miniscrews.
(Aust Orthod J 2008; 24: 134–139)
Received for publication: August 2008
Accepted: October 2008
Sulainee Kokitsawat: Sulaineeko@hotmail.com
Montien Manosudprasit: Monman@kku.ac.th
Keith Godfrey: keith_and_jill@yahoo.com.au
Charunee Ratanayatikul: Chakhut@gmail.com
Risk factors and indications of orthodontic
temporary anchorage devices: a literature review
Sofie Hoste,* Marjolein Vercruyssen,† Marc Quirynen† and Guy Willems*
Departments of Orthodontics and Forensic Dentistry* and Periodontology† School of Dentistry, Katholieke Universiteit Leuven, Belgium
Aims: The aims of this review are twofold, firstly, to give an overview of the general and local risk factors when using
temporary anchorage devices (TADs) and the prerequisites for placement and, secondly, to illustrate the orthodontic indications
of various TADs.
Methods: The PubMed database was searched for original articles on: ‘orthodontics and miniscrews/mini-implants/
miniplates/temporary anchorage devices/titanium screws/skeletal anchorage’, ‘miniscrews/mini-implants/miniplates and
risk factors/biomechanics/placement procedure’. Only articles published between 2001 and December 2007 were used.
In addition, each article was hand searched for references that may have been missed by the PubMed search.
Results: General risk factors are factors concerning general health. Bone quality and oral hygiene are local risk factors. Aspects
of the placement procedure discussed were: primary stability, loading protocols, pre-drilling diameter and whether or not to
make an intra-oral incision. A selection of published case reports is given to illustrate some orthodontic indications of TADs.
Conclusions: Temporary anchorage devices have a place in modern orthodontics. Careful treatment planning involving
radiographic examination is essential. Consultation with an oral surgeon is advisable if a soft tissue flap is required. Excellent
patient compliance, particularly avoidance of inflammation around the implant, is an important consideration for successful use
of TADs.
(Aust Orthod J 2008; 24: 140–148)
Received for publication: July 2008
Accepted: August 2008
Assisted eruption of impacted teeth into an
alveolar bone graft in a patient with cleft lip
and palate
Chonthicha Peamkaroonrath, Montien Manosudprasit and Keith Godfrey
Department of Orthodontics, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
Aims: To assist the eruption of impacted upper teeth into an alveolar bone graft in a patient with a unilateral cleft lip and
palate.
Methods: An 8 year-old Thai boy with left unilateral complete cleft lip and palate had the chief complaint of anterior crossbite.
He presented with a mild skeletal 3, dental Class III subdivision malocclusion, anterior crossbite, left unilateral posterior
crossbite, moderate crowding in the upper arch with impaction of upper the left lateral incisor (tooth 22) and canine (tooth 23).
In the first phase of treatment the posterior crossbite was corrected with a removable appliance with a 3-way screw. In the
second phase the impacted teeth were surgically exposed, moved into the alveolar bone graft and the teeth aligned with fixed
appliances. The upper left lateral incisor was extracted because of its questionable longevity.
Results: The orthodontic treatment resulted in normal overjet, overbite and an acceptable facial profile. A prosthesis replaced
tooth 22.
Conclusions: Forced eruption of impacted teeth can be carried out successfully in the cleft patients after an appropriate
treatment plan has been formulated and following preparation of alveolar bone graft in the cleft site.
(Aust Orthod J 2008; 24: 149–155)
Received for publication: January 2008
Accepted: April 2008
Chonthicha Peamkaroonrath: honggip@yahoo.com
Montien Manosudprasit: montien3@hotmail.com
Keith Godfrey: keith_and_jill@yahoo.com.au
Treatment of severe bimaxillary protrusion
with miniscrew anchorage: treatment
and complications
Hiroshi Mimura
Specialist practice, Tokyo, Japan
Background: Problems involving excessive face height and severe bimaxillary protrusion are usually treated with orthognathic
surgery. When this form of treatment is rejected, retraction and intrusion of the anterior teeth using skeletal anchorage afforded
by miniscrews may be employed.
Aims: To describe the treatment of severe bimaxillary protrusion with the aid of miniscrews and to discuss the complications
encountered during treatment.
Methods: Following extraction of the four first premolars, miniscrews were placed bilaterally in both jaws to permit maximum
retraction of the anterior teeth, and intrusion of the posterior and upper anterior teeth.
Results: The upper incisors were retracted 12 mm and intruded 5 mm over 20 months. The mandible rotated forward and
upward, the face height reduced and the facial aesthetics improved. During treatment an irregular ridge of bone developed
labial to the upper incisors, bone was deposited in the incisive fossae and the apices of the upper incisors were resorbed.
An alveoloplasty was carried out to recontour the labial bone and the incisive fossae.
Conclusions: Absolute anchorage provided by miniscrews may become an effective alternative to orthognathic surgery for
treatment of severe bimaxillary protrusion. During extensive retraction, the teeth may contact structures not normally encountered
during conventional orthodontic treatment.
(Aust Orthod J 2008; 24: 156–163)
Received for publication: April 2008
Accepted: July 2008
Hiroshi Mimura: mimura@m-ortho.com