The effect of buccolingual root angulation on the mesiodistal image perception for panoramic images
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REVIEWS AND ABSTRACTS Book reviews and article abstracts Alex Jacobson Birmingham, Ala THESIS ABSTRACTS Variation in orthodontic treatment planning decisions of Class II cases between virtual 3D models and traditional plaster study models Josh Whetten University of Alberta, Edmonton, Alberta, Canada Objective: The purpose of this study was to evaluate whether the use of digital models would elicit treatment deci- sions that varied compared with traditional plaster models. Methods: Pretreatment records of 10 patients with Class II malocclusions were assessed by 20 orthodontists serving as the variable group. The records were viewed at 2 time points at least a month apart, with the model format being changed at the second session. To serve as a control or standard, a second group of 11 orthodontists evaluated the same 10 cases twice but examined the plaster models on both occasions. Results: Orthodontists were scored on consistency of treatment decisions based on surgery, extraction, and auxil- iary appliance use. Because the data consisted of matched pairs and were nominal, the McNemar test and the kappa statistic were used to assess intrarater reliability. Addition- ally, a proportion of agreement was calculated for each group. Neither group showed statistically significant differences in decisions made. Conclusions: Digital models are a valid tool for use in treatment planning, even for difficult orthodontic cases. Alex Jacobson Am J Orthod Dentofacial Orthop 2005;128:262 0889-5406/$30.00 Copyright © 2005 by the American Association of Orthodontists. doi:10.1016/j.ajodo.2005.05.003 Paramedian palate morphology in the adolescent: a cone beam computed tomography study Keith King University of Alberta, Edmonton, Alberta, Canada Objective: The aims of this study were to (1) determine whether a relationship exists between the available bone in the paramedian palate (PP) and age, sex, and palatal morphol- ogy in growing patients; and (2) identify the most appropriate locations for PP implantation, considering available bone and interference of adjacent tooth roots. Methods: Cone beam computed tomography (CBCT) scans (NewTom 9000, Verona, Italy) were acquired in 183 orthodontic patients (10-19 years old). Paracoronal views of the PP region were reconstructed (eFilm workstation, Mil- waukee, Wis) at 4, 8, and 12 mm posterior from the incisive foramen, and measurements of bone height made in each reconstruction at 3-, 6-, and 9-mm increments laterally from the midline to describe the PP. Results: Significant variability in bone thickness was found between locations and subjects. Male subjects had significantly greater mean bone thickness in 6 of 9 locations measured. Age and palatal measurements did not demonstrate a clinically useful relationship to bone thickness. At the location 4 mm posterior to the incisive foramen and 3 mm lateral to the midline, 93% of male and 91% of female subjects met the criterion for implan- tation. At 8 mm posterior to the incisive foramen and 3 mm lateral to the midline, 86% of male and 58% of female subjects met the criterion for implantation. Conclusions: The PP meets the orthodontic implant placement criterion in growing patients over a wide age range, with males having more bone availability than females in general. Age and palatal morphology are not valid predic- tors of bone height in the PP. Because of large variability of bone thickness in this region, CBCT remains valuable before paramedian implant placement in growing patients. Because implant placement in the midpalatal suture is contraindicated in growing patients, the PP is a promising region for palatal implant placements. CBCT allows accurate measurement of PP bone height but adds cost and radiation exposure. Alex Jacobson Am J Orthod Dentofacial Orthop 2005;128:262 0889-5406/$30.00 Copyright © 2005 by the American Association of Orthodontists. doi:10.1016/j.ajodo.2005.05.004 The effect of buccolingual root angulation on the mesiodistal image perception for panoramic images Mariano Garcia University of Alberta, Edmonton, Alberta, Canada Objective: This study was carried out to assess the effect of buccolingual root orientation on the perception of mesio- distal angulation and parallelism for panoramic images. Methods: A skull-typodont phantom was constructed according to cephalometric norms. The bases of the typodont were partially sectioned so that the buccolingual orientation of 8 different teeth could be easily modified. The teeth chosen were the maxillary right lateral incisor, the maxillary right 262 American Journal of Orthodontics and Dentofacial Orthopedics /August 2005
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Transcript of The effect of buccolingual root angulation on the mesiodistal image perception for panoramic images
REVIEWS AND ABSTRACTS
Book reviews and article abstractsAlex JacobsonBirmingham, Ala
THESIS ABSTRACTS
Variation in orthodontic treatmentplanning decisions of Class II casesbetween virtual 3D models andtraditional plaster study modelsJosh WhettenUniversity of Alberta, Edmonton, Alberta, Canada
Objective: The purpose of this study was to evaluatewhether the use of digital models would elicit treatment deci-sions that varied compared with traditional plaster models.
Methods: Pretreatment records of 10 patients with ClassII malocclusions were assessed by 20 orthodontists serving asthe variable group. The records were viewed at 2 time pointsat least a month apart, with the model format being changedat the second session. To serve as a control or standard, asecond group of 11 orthodontists evaluated the same 10 casestwice but examined the plaster models on both occasions.
Results: Orthodontists were scored on consistency oftreatment decisions based on surgery, extraction, and auxil-iary appliance use. Because the data consisted of matchedpairs and were nominal, the McNemar test and the kappastatistic were used to assess intrarater reliability. Addition-ally, a proportion of agreement was calculated for each group.Neither group showed statistically significant differences indecisions made.
Conclusions: Digital models are a valid tool for use intreatment planning, even for difficult orthodontic cases.
Alex JacobsonAm J Orthod Dentofacial Orthop 2005;128:2620889-5406/$30.00Copyright © 2005 by the American Association of Orthodontists.doi:10.1016/j.ajodo.2005.05.003
Paramedian palate morphology in theadolescent: a cone beam computedtomography studyKeith KingUniversity of Alberta, Edmonton, Alberta, Canada
Objective: The aims of this study were to (1) determinewhether a relationship exists between the available bone inthe paramedian palate (PP) and age, sex, and palatal morphol-ogy in growing patients; and (2) identify the most appropriatelocations for PP implantation, considering available bone andinterference of adjacent tooth roots.
Methods: Cone beam computed tomography (CBCT)scans (NewTom 9000, Verona, Italy) were acquired in 183orthodontic patients (10-19 years old). Paracoronal views ofthe PP region were reconstructed (eFilm workstation, Mil-waukee, Wis) at 4, 8, and 12 mm posterior from the incisiveforamen, and measurements of bone height made in eachreconstruction at 3-, 6-, and 9-mm increments laterally fromthe midline to describe the PP.
Results: Significant variability in bone thickness was foundbetween locations and subjects. Male subjects had significantlygreater mean bone thickness in 6 of 9 locations measured. Ageand palatal measurements did not demonstrate a clinically usefulrelationship to bone thickness. At the location 4 mm posterior tothe incisive foramen and 3 mm lateral to the midline, 93% ofmale and 91% of female subjects met the criterion for implan-tation. At 8 mm posterior to the incisive foramen and 3 mmlateral to the midline, 86% of male and 58% of female subjectsmet the criterion for implantation.
Conclusions: The PP meets the orthodontic implantplacement criterion in growing patients over a wide agerange, with males having more bone availability than femalesin general. Age and palatal morphology are not valid predic-tors of bone height in the PP. Because of large variability ofbone thickness in this region, CBCT remains valuable beforeparamedian implant placement in growing patients. Becauseimplant placement in the midpalatal suture is contraindicatedin growing patients, the PP is a promising region for palatalimplant placements. CBCT allows accurate measurement ofPP bone height but adds cost and radiation exposure.
Alex JacobsonAm J Orthod Dentofacial Orthop 2005;128:2620889-5406/$30.00Copyright © 2005 by the American Association of Orthodontists.doi:10.1016/j.ajodo.2005.05.004
The effect of buccolingual rootangulation on the mesiodistal imageperception for panoramic imagesMariano GarciaUniversity of Alberta, Edmonton, Alberta, Canada
Objective: This study was carried out to assess the effectof buccolingual root orientation on the perception of mesio-distal angulation and parallelism for panoramic images.
Methods: A skull-typodont phantom was constructedaccording to cephalometric norms. The bases of the typodontwere partially sectioned so that the buccolingual orientationof 8 different teeth could be easily modified. The teeth chosenwere the maxillary right lateral incisor, the maxillary right
262 American Journal of Orthodontics and Dentofacial Orthopedics/August 2005
central incisor, the maxillary left canine, the maxillary leftfirst premolar, the left mandibular incisors, the mandibularright canine, and the mandibular right first premolar. Threedifferent buccolingual angulations were used for each tooth(original; root rotated toward the buccal aspect 10°; rootrotated toward the lingual aspect 10°). Nine buccolingualangulation settings were necessary to analyze all buccolin-gual-orientation combinations between adjacent teeth. Thetrue mesiodistal and buccolingual tooth angulations relativeto an orthodontic archwire were calculated with a tridimen-sional coordinate measuring machine. The panoramic filmswere scanned and digitized with custom-designed software todetermine the image mesiodistal angulations.
Results: Almost all the image angles for each tooth hadat least one angle measurement that was statistically differentfrom the other mesiodistal angles with different buccolingualorientations. Nevertheless, if applying clinical tolerance lim-its, only 50% of the image mesiodistal angles for each toothwere clinically different from each other. Variations of asmuch as � 2.5° between a tooth and a reference line on thefilm might be considered clinically insignificant according toprevious researchers. If this criterion is applied, only theimage mesiodistal angulations of the canine and premolarregions in both arches can be considered clinically andstatistically significantly different. The panoramic image ingeneral overestimated the mesiodistal angulations of teeththat had a buccal root angulation, while underestimating theones that had a lingual root orientation. The roots with buccalroot orientations were projected more distally than they werein reality, and roots lingually positioned were projected moremesially. This phenomenon was more pronounced in themaxilla than the mandible. The largest root parallelismdifferences for adjacent teeth occurred between the maxillarycanine and first premolar, and the second largest differenceswas in the mandibular canine/premolar area.
Conclusions: Buccolingual orientation changes do notseem to affect the root parallelism expression in the incisorarea. The clinical usefulness of panoramic radiography toasses the mesiodistal tooth angulation should be approachedwith caution. An understanding of the buccolingual orienta-tion effects on the image mesiodistal angulation expressionsfor panoramic images is extremely necessary, especially inthe premolar extraction site.
Alex JacobsonAm J Orthod Dentofacial Orthop 2005;128:262-30889-5406/$30.00Copyright © 2005 by the American Association of Orthodontists.doi:10.1016/j.ajodo.2005.05.005
Reproducibility of the DIAGNOdentinstrument to assess enamel smoothsurface integrity in pre- and post-bonded orthodontic patientsAly B. KananiUniversity of Detroit Mercy, Detroit, Mich
Introduction: Demineralization adjacent to orthodonticbrackets is a serious potential complication of orthodontic
treatment. Techniques to screen, monitor, and quantify earlylevels of decalcification around orthodontic brackets aredeficient.
Objective: The aim of this study was to evaluate thereproducibility of the DIAGNOdent instrument in assessingred laser-induced fluorescence for the measurement of de-mineralization around brackets in vivo and to assess thepossible effect of the bracket and bonding system on DIAG-NOdent readouts.
Methods: Measurement sites on 430 prebracketed and344 postbracketed teeth at the cervical third of the facial/buccal smooth surfaces were made. Fluorescence was mea-sured on prebonded and immediately postbonded bracketedteeth. Transbond XT Self Etching Primer and Transbond XTAdhesive were used as the bonding medium. Three outcomeswere measured: (1) inter-operator reliability between 2 oper-ators measuring every site, (2) intraoperator reliability, and(3) the difference between prebonded and immediately post-bonded smooth surface enamel areas gingival to the bondedbrackets.
Results: Interoperator reliability was excellent at98.60%, with K � 0.98 (agreement within � 2) beforebonding, and 98.00%, with K � 0.97 (agreement within � 2)immediately after bonding. Intraoperator agreement alsoshowed remarkable reproducibility with K � 1.00 (agreementwithin � 1). Paired t tests showed an overall mean decreasein instrument readings of 0.90 (P � .003) between prebondand immediately postbonded teeth. Although there is astatistically significant difference between prebonded andpostbonded readouts in vivo, the change is within the windowof measurement error and is not clinically significant.
Conclusions: These results suggest that the DIAGNO-dent instrument can be used reproducibly on enamel smoothsurfaces and adjacent to orthodontic brackets in vivo.
Alex JacobsonAm J Orthod Dentofacial Orthop 2005;128:2630889-5406/$30.00Copyright © 2005 by the American Association of Orthodontists.doi:10.1016/j.ajodo.2005.05.006
Evaluation of frictional resistance inresin self-ligating bracket, stainlesssteel self-ligating bracket and ceramicbracketsVladimir TabakmanUniversity of Detroit Mercy, Detroit, Mich
Objective: This in vitro study was designed to comparethe frictional resistance in a new polycrystalline polymerself-ligating bracket (Opal, Ultradent), stainless-steel self-ligating bracket (Inovation, GAC), polycrystalline ceramicbracket with a heat-glazed silicate slot along with recessedproximal slot edges (Mystique, GAC), ceramic with metalslot insert (Clarity, 3M/Unitek), and monocrystalline sapphireceramic (Inspire, Ormco).
Methods: An Instron universal testing machine was usedto measure the friction created by pulling straight pieces of
American Journal of Orthodontics and Dentofacial OrthopedicsVolume 128, Number 2
Reviews and abstracts 263
