Comparison of speed and accuracy between manual and computer-aided measurements of dental arch and jaw arch lengths in study model casts

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1 Compariso of speed ad accuracy betwee maual ad computeraided measuremets (Diah Wibisoo, et.al.) Compariso of speed ad accuracy betwee maual ad computeraided measuremets of detal arch ad jaw arch legths i study model casts Diah Wibisoo, Bergma Thahar, Too S. Hambali, Joo Salim Departmet of Orthodotic, Faculty of Detistry, Uiversitas Padjadjara ABSTRACT This research is aimed at observig whether there are differeces i the measuremet results betwee detal arch legth ad arch legth measured maually ad by usig computer software, i.e. Corel Draw 12, i study model cast as well as the measuremet speed i both techiques. The method used i this research is the descriptive comparative method. The measuremet is performed to 52 study model cast samples with the Spee Curve depth of < 1.5 mm, betwee 1.5 ad 3 mm,. The measuremets are performed usig 2 techiques: maual techique usig caliper ad by usig Corel Draw 12, a computer program with computer scaer. The ttest statistic is used to reveal whether there are differeces i the measuremet results betwee the two techiques ad which method eeds shorter time. Statistically, there are sigificat differeces either i the speed of the measuremet or the results of the measuremet usig both techique where tcalculated > le. The deeper the Spee curve, the more differet the results from the maual techique ad computed techique. The differeces are i the rage of 0.32 to 0.52 mm for detal arch legth ad 0.33 to 0.43 mm for arch legth. These differeces are still acceptable cliically. By referrig to the results of this research, it is epected that computer usage ca be icreased ad become a alterative agaist maual techique of measuremet. Key words: Detal arch legth measuremet, speed of the measuremet, maual techique, Corel Draw 12 R INTRODUCTION A study model cast is a stadard compoet of iformatio source for diagosig ad plaig the treatmet of a special case. Other compoets iclude facial ad itraoral photographs, ray photographs, ad medical record cards. 1,2 From a study model cast, it is possible to obtai iformatio about detal shape, dimesio, coditio, ad positio, ad legth of jaw arch. A study model cast also gives us a threedimesioal image of the itraoral coditio. 1,3 Dividers, Boley Gauge, Verier Gauge, ad electroic digital calipers are amog the istrumets commoly used to measure mesiodetal width. 4,5,6,7 For maual measuremet of jaw arch legth, dividers or brass wire are ofte used. 8 A patet o a computer model system that ca geerate digital images from a study model cast has bee grated to ORTHOCAD (Cadet Fairview, NJ). ORTHOCAD produces a software program that ca be operated by orthodotists to perform study model cast routie measuremets of detal dimesio, overjet, overbite, ad to perform Correspodece author: Diah Wibisoo, Departmet of Orthodotic. Faculty of Detistry Uiversitas Padjadjara Jl. Sekeloa Selata No.1 Badug, West JavaIdoesia, Tel./Fa /

2 Padjadjara Joural of Detistry 2007, (1):. Bolto aalysis. The software ca also geerate multiagle images of upper jaw occlusio. 2,9 Measuremet of detal ad jaw arch legth i a study model cast has bee performed maually with a pair of sharppoited dividers. With the curret developmet i computer techology, there is ow available i market a software program called Corel Draw 12, which ca be used to create graphic desigs. There is also a scaer that ca covert a image ito a digital format with the help of a computer set. The preset writer coceives this techological developmet as iterestig. If the combied use of a computer set, software program, ad scaer ca be applied i the field of orthodotics to produce accurate ad reliable results, especially from a study model cast, it is the possible to store the iformatio from a study model cast i a digital or electroic format. The techology ca be very useful i orthodotic iformatio maagemet. With this techology, a orthodotist ca quickly retrieve the required detal iformatio ad commuicate it to the patiet. 2,10 Sice time is ow a major cocer for most idividuals, a computeraided procedure ca be coceived as a way to get thigs doe more quickly ad easily. Both maual ad computeraided study model measuremets have their ow procedures. The more a practitioer is accustomed to a ew system, the faster ad more accurate the measuremet is. 1,11 The research aims to compare the speed ad accuracy betwee maual ad computeraided measuremets of detal arch ad jaw arch legths of study model casts. opebite aterior or posterior); depth differece betwee left ad right s does ot eceed 0.5 mm; there was o abormality i detal aatomy, o broke teeth i the study models; o airbulbs i study model casts; o attritio, caries, or filligs that ca alter the mesiodistal measuremet of detal crows. Maual measuremets of the 52 study model casts were performed i the followig maer: Detal arch ad jaw arch legths are measured with a pair of dividers; measuremet results are recorded; speed is measured with a stopwatch. Computeraided measuremet follows the followig procedure: the study model casts are scaed, the results of which are fed ito Corel Draw 12 computer software program. Detal arch legth is measured by placig poits with a computer mouse o wider mesiodistals as they appear o the moitor scree. Figure 1. Lower jaw study model cast is placed o scaer METHOD The research employed the descriptivecomparative method, by which data are aalyzed with Studet s ttest. A total of 53 study model casts are sampled. The samples cosisted of study model casts with Spee s Curve depths of <1.5 mm, study model casts with depths of 1.5 to 3 mm, ad study model casts with depths of over 3 mm. The sample criteria 1,2 were as follows: permaet teeth have erupted from right to left first molar; there are o missig teeth betwee right first molar ad left first molar; occlusio of upper jaw teeth follows lower jaw (o Figure 2. Measuremet of iterdetal width

3 Compariso of speed ad accuracy betwee maual ad computeraided measuremets (Diah Wibisoo, et.al.) Table 1. Aalysis of average ideticality test betwee the results of maual ad computeraided measuremets of detal arch legth M C t M C t mm Table 2. Aalysis of average ideticality test betwee the results of maual ad computeraided measuremets of jaw arch legth M C t M C t mm Table 3. Aalysis of ideticality test betwee maual ad computeraided detal arch ad jaw arch legth measuremet speed Time (secod) M C t mm *) *) *) Note: X M C t hit *) Upper Jaw Average Lower Jaw Stadard Deviatio Maual (milimeter) Number of Study Model Casts Computeraided (milimeter) Calculated t Sigificat ttable

4 Padjadjara Joural of Detistry 2007, (1):. The process starts from the first right permaet molar distal ed to the first left permaet molar distal ed. Legth readig speed is measured with a stopwatch. Measuremet results are the recorded. Jaw arch legth is measured by placig poits o the alveolar ridges of the 6 segmets, from the distal ed of the first permaet right molar to the distal ed of the first permaet left molar. Measured legths are the recorded. A stopwatch is used to measure the speed of jaw arch legth measuremet. The research is udertake at the Postgraduate Cliic of the Faculty of Detistry from September 2005 to Desember The populatio of the research was the 516 study model casts of patiets of the Orthodotic Specialist Cliic, The Faculty of Detistry, Uiversitas Padjadjara, betwee 2002 ad 2005, before ad after orthodotic braces placemet. RESULTS Detal arch legth measuremet variables are show i table 1. Jaw arch legth measuremet variables are show i table 2. Compariso of detal arch ad jaw arch legth measuremet speed betwee the maual ad computeraided techiques is preseted i table 3. Aalysis Statistically, the overall results of maual ad computeraided measuremet techiques show sigificat differeces.this meas that the maual ad computeraided measuremets of detal arch ad jaw arch legths of model study casts with differet depths (<1.5 mm, 1.53 mm, ad >3 mm) will yield differet values. The results of computeraided measuremets of detal arch ad jaw arch legths were greater i values tha those of the maual techique. The deeper the cast, the greater the differece. This fidig is supported by previous studies, that the results of computeraided measuremets are greater i values tha those of the maual techique. Errors i the form of value augmetatio ad dimiutio may occur due to the positio of the detal cast away from the scaer glass surface. Aother factor that ca cause differeces is the placemet of idetificatio poits o the moitor scree. 2,6 Difficulties i placig poits o the study model cast image o the moitor scree affect the accuracy of the measuremet. From a statistical poit of view, the differeces i results betwee the maual ad computeraided techiques were sigificat. However, a lesstha0.5 mm. Margi will make virtually o differece i detal diagoses ad treatmet plas. I the maual measuremet of a study model cast, i which a ruler ad a pair of dividers are used, it is a commo practice to roud values up or dow to a margi of 0.5 mm. I space aalysis, jaw arch legth i this case, it is sufficiet to roud values up or dow to a 0.5 mm margi. 12 Previous researches agree that such a margi will ot result i sigificat cliical impacts. It takes more time for the computeraided techique to perform measuremets of detal arch ad jaw arch legths of study model casts with various depths. This fidig is icosistet with the results of the previous researches, which idicate that a simple computer program ca icrease study model cast measuremet speed ad that the more a practitioer is accustomed to the system, the more the speed will icrease. 1,13 I the preset study, maual measuremet takes less time sice the process ca be applied directly to the study model cast without ay eed to sca ad place poits o the moitor scree image of the cast as is ecessary whe the computeraided techique is used. CONCLUSION Computeraided measuremet of detal arch ad jaw arch legths of a study model cast ca be applied as a alterative to the maual techique. However, careful cosideratios must be give regardig the biases that may result alog with the icrease of depths. How a practitioer places idetificatio poits o the moitor scree also plays a importat role i determiig the accuracy of computeraided measuremet. The computeraided measuremet techique takes more time tha the maual oe does.

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