Volume 21, No.2 - November 2005
Original Articles
Personality traits in adolescence and satisfaction with orthodontic treatment in young adulthood
Matthew J. Barker, W. Murray Thomson and Richie Poulton
Factors influencing the non-surgical eruption of palatally impacted canines
Richard J. Olive
Force systems yielded by different designs of T-loop
Guilherme Thiesen, Marcus Vinicius Neiva Nunes do Rego, Luciane Macedo de Menezes and Roberto Hideo Shimizu
Mandibular arch changes following nonextraction treatment
David T. Waring, Neil Pender and Dan Counihan
Physical properties of human premolar cementum: hardness and elasticity
Wanjira Chutimanutskul, M. Ali Darendeliler, Michael V. Swain, Gang Shen and Peter Petocz
SmartClip versus conventional twin brackets for initial alignment: is there a difference?
Peter C. Miles
Case Reports
Maxillary molar intrusion with micro-implant anchorage (MIA)
Hyo-Sang Park, Bong-Kyu Jang and Hee-Moon Kyung
Treatment protocol for unilateral cleft lip and palate patients: questioned by two case reports
Medhat Aly, Anna Verdonck, Carine Carels and Guy Willems
Abstracts
Personality traits in adolescence and satisfaction with orthodontic treatment in young adulthood
Matthew J. Barker,* W. Murray Thomson* and Richie PoultonÜ
Departments of Oral Sciences* and Preventive and Social Medicine,Ü University of Otago, New Zealand
Objective: This study aimed to determine whether personality traits are associated with satisfaction with orthodontic treatment by age 26.
Methods: A prospective observational cohort study was conducted with 1,037 individuals, one-third of whom had received orthodontic treatment by age 26. A comprehensive personality assessment was conducted at age 18 using the multidimensional personality questionnaire. At age 26, orthodontic outcome was rated as either ëExcellent', ëPretty good', ëFair' or ëPoor'.
Results: Those who were less satisfied (rating their treatment outcome as ëFair' or ëPoor') scored lower on the personality traits of control and social closeness, and higher on stress reactivity. Individuals with low scores on social closeness were twice as likely (Odds ratio: 2.07) to be less satisfied with their orthodontic result.
Conclusions: Individuals who are impulsive, stress-reactive or socially isolated are more likely to be disappointed with their orthodontic outcome. Pretreatment knowledge about certain aspects of personality might be useful to practising orthodontists.
(Aust Orthod J 2005; 21: 87ñ93)
Received for publication: May 2005
Accepted: September 2005
Factors influencing the non-surgical eruption of palatally impacted canines
Richard J. Olive
Brisbane, Australia
Background: Many palatally impacted canines in children do not require surgical exposure prior to the start of orthodontic treatment. They erupt in mid-alveolar positions providing excess space is made for them in the arch. The time required for an impacted tooth to emerge under these conditions is highly variable.
Aim: To determine the factors influencing the time required for a palatally impacted canine to spontaneously disimpact following orthodontic treatment to create excess space in the arch.
Method: Thirty palatally impacted canines, which emerged following orthodontic treatment to open excess space in the arch, were used. The impacted teeth were present in 28 children. No canines were surgically exposed. The positions of the impacted canines before treatment, the mesiodistal widths and rotations of the adjacent and contralateral lateral incisors, age and gender of the subjects, subjects' dental ages, presence of either incisor or premolar hypodontia, number of subjects with bilaterally impacted canines, and number of siblings with impacted canines were recorded. Canines that erupted in less than nine months of treatment were compared with canines that required more than nine months of treatment. The canines were grouped by severity of impaction (sectors II - IV) and compared.
Results: There were significantly more severe (sector IV) impactions in the long duration group compared with the short duration group. Significantly more cases of incisor - premolar hypodontia were found in the short duration group. Canines impacted in sector IV emerged after 21 months of treatment and canines in sectors II and III emerged after eight months of treatment. Lateral incisors adjacent to the impacted teeth were rotated mesiolabially to a greater extent in the sector IV group compared with lateral incisors in the sector II group. Differences in rotation of the adjacent and contralateral lateral incisors were significantly less in the sector II group compared with the lateral incisors in the sector III and IV groups.
Conclusions: The sector of impaction was the best guide to the duration of treatment prior to emergence.
(Aust Orthod J 2005; 21: 95ñ101)
Received for publication: August 2004
Accepted: February 2005
Force systems yielded by different designs of T-loop
Guilherme Thiesen,* Marcus Vinicius Neiva Nunes do Rego,Ü Luciane Macedo de Menezesá and Roberto Hideo Shimizu §
Unisul Dental School,* Novafapi Dental School,Ü Pontifical Catholic University of Rio Grande do Sul Dental School,á Tuiuti University Dental School,§ Brazil
Objectives: To determine the mechanical characteristics of beta-titanium T-loops with and without helices, with 0 and 180 degree gable bends and constructed from 0.017 inch x 0.025 inch and 0.019 inch x 0.025 inch wire.
Methods: Forty beta-titanium T-loops were centrally positioned in a universal testing machine. The horizontal force and the moment/force ratios during activation were recorded at 1 mm intervals, up to a maximum of 7 mm. The data were analysed with analysis of variance complemented by the Tukey test for multiple comparisons.
Results: The results demonstrated that the transverse section of the wire had the greatest effect on the horizontal force produced by the loops. Significantly lower levels of horizontal force were obtained with loops made with the smaller 0.017 inch x 0.025 inch wire. Loops with gable bends yielded high moment/force ratios, whereas loops without gable bends had low moment/force ratios. In general, T-loops with helices yielded lower magnitudes of horizontal force and moment/force ratios than plain T-loops.
Conclusions: The horizontal forces and moment/force ratios generated by plain T-loops with 180 degree gable bends yielded more adequate force systems. Incorporation of helices in the design of T-loops seems to be unnecessary.
(Aust Orthod J 2005; 21: 103ñ110)
Received for publication: November 2004
Accepted: July 2005
Mandibular arch changes following
nonextraction treatment
David T. Waring,* Neil Pender* and Dan Counihan†
University Dental Hospital of Liverpool, United Kingdom,* and Tralee, Eire†
Objective: To evaluate mandibular tooth position changes following treatment with a lip bumper and fixed appliance.
Specifically, we aimed to determine how space was obtained to align crowded lower incisors.
Methods: Thirty-four consecutively treated children with a mean age of 10.6 years (SD: 1.14 years) were selected from a
specialist orthodontic practice in Eire. All subjects were treated with a lip bumper followed by a fixed appliance. The positions
and angulations of the lower first molars and most proclined lower incisor were measured on the pretreatment and posttreatment
lateral cephalometric radiographs and study models with a reflex metrograph. The changes were also compared with
published growth data.
Results: After lip bumper and fixed appliance treatment the mandibular arch depth decreased (Mean difference: 1.2 mm;
p < 0.01) and the mandibular intermolar width increased (Mean difference: 1.73mm; p < 0.01). The mandibular molars
moved mesially (Mean difference: 2.14 mm; p < 0.01) and tipped distally (Mean difference: 4.36 degrees; p < 0.01).
There were no significant differences between the pre- and post-treatment positions or angulations of the mandibular incisors.
Compared to published growth data the arch depth decreased less, the intermolar width increased more and the mandibular
molars were uprighted. There was no difference in the positions of the mandibular incisors in the treated group compared with
published growth data.
Conclusions: The main effects of nonextraction treatment with a lip bumper followed by fixed appliance treatment were to maintain
the leeway space, expand the mandibular arch and ‘upright’ the lower molars. The treatment had no effect on the position
of the lower incisors.
(Aust Orthod J 2005; 21: 111–116)
Received for publication: February 2005
Accepted: July 2005
Physical properties of human premolar cementum: hardness and elasticity
Wanjira Chutimanutskul,* M. Ali Darendeliler,* Michael V. Swain,* Gang Shen* and Peter Petocz*Ü
Faculty of Dentistry, Sydney Dental Hospital, The University of Sydney,* and Macquarie University,Ü Australia
Aims: To determine if the cementum on the maxillary right and left first premolars has identical physical properties.
Methods: Ten normal maxillary first premolar teeth, extracted from five orthodontic patients with a mean age of 14.0 years, were used. The teeth had not been subjected to an orthodontic force. The hardness and elastic modulus of the cementum were measured on the buccal and lingual surfaces of the roots at three locations: cervical third, middle third and apical third.
Results: There were no significant side-to-side differences in cementum hardness (Mean side-to-side difference: 0.0063 GPa; SD: 0.0279; p = 0.525) or elastic modulus (Mean side-to-side difference: ñ0.027 GPa; SD: 0.111; p = 0.814). The hardness and elastic modulus of the cementum decreased from cervical to apical regions on both root surfaces.
Conclusions: Similar physical properties of the cementum on the maxillary right and left first premolars suggest that intra-arch comparisons can be used to investigate root resorption caused by orthodontic forces.
(Aust Orthod J 2005; 21: 117ñ121)
Received for publication: June 2005
Accepted: September 2005
SmartClip versus conventional twin brackets for initial alignment: is there a difference?
Peter G. Miles
Caloundra, Queensland, Australia
Objective: To compare the effectiveness of SmartClip brackets and conventional twin brackets for initial alignment of the lower arch.
Methods: Fifty-eight patients participated in this prospective trial. The patients were assigned alternately to either a group treated with SmartClip MBT prescription brackets or a group treated with conventional MBT twin brackets. Lower anterior irregularity was measured at the start of treatment, 10 weeks later at the first archwire change and 20 weeks after the start of treatment at the second archwire change.
Results: There was no difference in irregularity at the start of treatment. At 10 weeks subjects treated with conventional brackets had a lower irregularity index than subjects treated with SmartClip brackets (Mean difference: 0.7 mm; p = 0.005). After 20 weeks there were no statistically significant differences in irregularity between the two groups (Mean difference: 0 mm; p = 0.82).
Conclusion: The SmartClip bracket was no more effective at reducing irregularity during the initial stage of treatment than a conventional twin bracket ligated with elastomeric modules or stainless steel ligatures.
(Aust Orthod J 2005; 21: 123ñ127)
Received for publication: August 2005
Accepted: September 2005
Case Reports
Maxillary molar intrusion with micro-implant anchorage (MIA)
Hyo-Sang Park, Bong-Kyu Jang and Hee-Moon Kyung
Department of Orthodontics, Kyungpook National University, Daegu, Korea
Background: Intrusion of the maxillary molars is difficult to accomplish using traditional methods of anchorage.
Aims: To describe methods of maxillary molar intrusion with the aid of micro-implants.
Methods: Micro-implants provide stable intra-oral anchorage and enable the maxillary molars to be intruded without the usual side effects. Three adult patients are presented showing how micro-implants can be used to intrude the maxillary molars. In the first patient micro-implants were placed in the alveolar process between the second premolar and first molar, in the second patient micro-implants were placed in the palatal alveolar process between the first and second molars, and in the third patient a micro-implant was placed in the palate paramedially. A transpalatal bar was used to prevent bucco- or linguoversion of the molars during intrusion.
Conclusions: The maxillary molars can be intruded with intra-oral anchorage derived from microscrew implants.
(Aust Orthod J 2005; 21: 129ñ135)
Received for publication: January 2005
Accepted: August 2005
Treatment protocol for unilateral cleft lip and palate patients: questioned by two case reports
Medhat Aly, Anna Verdonck, Carine Carels and Guy Willems
School of Dentistry, Katholieke Universiteit Leuven, Belgium
Background: The types and severity of clefts as well as palatal development and growth in children with repaired cleft lip and palate deformities can vary greatly. Independent of the technique used surgery produces scar tissue, which restricts palatal growth so that by the second decade many patients have an underdeveloped maxilla. Experience has shown that the maxillary retrognathism found in many cleft patients is not amenable to nonsurgical correction. Few long-term studies have evaluated the procedures, sequencing and timing of the treatment methods found to give the best results. This lack of reliable information means there is a serious gap in our ability to assess the value of different treatment modalities.
Aims and methods: From the viewpoint of orthodontics, this article describes the treatment protocol used by the cleft lip and palate team at the University Hospitals of the KU Leuven. The present treatment protocol is illustrated and questioned by two cases. The roles of prediction of facial growth and distraction osteogenesis are discussed.
(Aust Orthod J 2005: 21: 137ñ148)
Received for publication: May 2005
Accepted: August 2005