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Correction of the measured values produced by the mandibular kinesiograph for the analysis of jaw movement around the rest position
Volume 85 Number 3
Reviews and abstracts
ment, and community dental health. Most of the illustrations are good, although some of the Kodachrome intraoral views that have been converted to black and white are washed out. Bibliographies are generally quite adequate at the end of each chapter. Production details are excellent, with good binding and paper quality, readable type, etc. There are a number of good pedodontic texts, but this certainly is one of the top-rung contributions that any practicing pedodontist would want on his shelf. T. hf. Graber
271
perimposition of tracings in longitudinal cephalometric analyses and offered a 70% improvement in accuracy over an observation period of one year. When the observation period was increased, a slight but significant reduction in precision was noted. The indications are that the maximum benefits may be expected for shortterm analyses of less than 3 years, and in particular for the x-coordinates of landmarks placed farther away from the cranial base. Nevertheless, photographic subtraction makes optimum use of image detail and thus offers significant improvements in the precision and reliability of radiographic cephalometric analysis. T. M. Graber
Photographic Subtraction Craniofacial Analysis
in
John Stuart McWilliam J. Dento-Maxi&-Facial
Radiol.,
Suppl.
4, 1983
The use of roentgenographic cephalometrics as a diagnostic tool in orthodontics is universally established as an aid both in diagnosing and in assessing growth and/or effects of orthodontic treatment. Orthodontic journals have published more cephalometric studies than in any other single area. Recently, however, a number of authors have questioned the reliability of such analyses. The aim of the present study was to determine whether or not photographic subtraction, in combination with direct digitizing of the films for the computer, could significantly reduce the errors encountered in craniofacial analysis. The author describes a general approach for evaluating digital measurements and describes how random and systematic errors can be detected and quantified. The latter can then be compensated for by suitable calibration of incoming data, whereas digitizing represents the optimal precision of the measuring system and can be used to follow aging of the instrument. A procedure for marking radiographs with four fiducial points is described and evaluated. This allows individual coordinate systems to be defined in order to facilitate duplication of landmark registration, addition of new landmarks to existing data, and definition of film orientation following superimposition procedures. The technique of photographic subtraction is applied to a study of condylar position. Acrylic indices were used to lock the mandible in centric relation during radiographic registrations. The analysis offered the most reliable results when bilateral instead of a onehanded pushback of the mandible was done prior to making of the radiograph. Evidence points to some posterior rotation of the mandible with this technique, however. Photographic subtraction was compared with su-
Aspectos de la Actividad Odontologica Durante el Conflict0 de las Malvinas Roberto Orlando Stvrtecky Revista
Assoc.
Odontol.
Argentina
71: 113-116,
1983
During the Anglo-Argentine conflict in the Malvinas (Falkland Islands), there was an interforce hospital in Puerto Argentino in which forty-five professionals and forty-four assistants rendered their services. Two of the assistants were dentists-one from the army and one from the air force. Three thousand fifty consultations for various types of pathosis were performed during peacetime. Then, with initiation of hostilities, there were 630 warassociated wound cases; 1,200 patients were sent to the hospital and 729 treatment procedures were carried out. Forty of these involved maxillofacial and dental complications and trauma. The most frequent cases were those due to shrapnel, bomb, or missile wounds. Following cessation of hostilities and during the imprisonment period, 69 treatment procedures were performed in Mount St. Edmund. They were of a dental nature and were performed with instruments and supplies that were provided by the British. T. M. Graber
Correction of the Measured Values Produced by the Mandibular Kinesiograph for the Analysis of Jaw Movement Around the Rest Position Satoshi Adachi, Keijiro Miyamoto, Masafumi Tsuchiya, Kenmi Yoshida, Kenji Takada, Yasuhiro Kakiuchi, Masaharu Kohbayashi, and Mamoru Sakuda J. Jpn.
Orthod.
Sot. 42: 297-306,
1983
The purpose of this study was to describe a new method for correction of the distorted original data obtained from the mandibular kinesiograph (MKG), to
272
Reviews and abstracts
Am. 1. Orthod. March 1984
analyze jaw movement quantitatively within a small range around the mandibular postural resting position, and to assess the reliability of this method. In order to investigate the amount of distortion involved in the MKG data, a parallel-sliding system was developed and connected with a three-dimensional digitizer (Gradicon) which was connected by an aluminum rod, in turn, to the magnet centered in the MKG sensor array. This assembly then was capable or registering the true X-Y-Z coordinates of the magnet’s position. The original MKG data were recorded directly by reading a digital tester at each of the magnet’s 168 positions, distributed at regular intervals with a range ofminus2toplus2mminX,minus2toplus lOinY, and 0 to minus 10 in Z coordinates. The formula for the correction, expressed by a dual equation of the second degree, was arrived at by inversely converting the equation which represents the distortion of the measured value received from the MKG. Then the true coordinates were compared to both the distorted original coordinates and the logically corrected coordinates for each dimension. The results showed that the distorted MKG data were sufficiently corrected to reduce the error to as small as 0.1 to 0.2 mm, and that this correction method had a good reliability for studying the jaw movements within a limited space around the mandibular postural resting position. T. M. Graber
An Experimental Study of the Displacement of the Maxillary Complex, Produced by Extraoral Forward Traction Toshiaki Tanabe, Kenji Suginome, Yasuhiko Yoshida, and Sadahiko Nlshiguchi J. Jpn.
Orthod.
Sot. 42: 322-335,
1983
While much of Class III therapy is directed toward the mandible, there is an increasing use of extraoral traction to the maxilla in skeletal Class III cases where there is manifest maxillary or midface deficiency. The precise nature of the effects of this type of extraoral traction to the maxilla have not been sufficiently studied as yet, so that the desired direction of pull, the amount of force, and the maxillary response can be determined ahead of time. Six dried human skulls were used for this study, to provide a model for a two-dimensional assessment of the maxillary complex and neighboring bones under varying vectors of maxillary traction in the horizontal and vertical directions. Ten loading points were set up on the model to assess the moving phase under extraoral traction.
When a dominantly forward extraoral traction force was applied, changing the loading point from the incisor area to the molar region, the maxillary complex exhibited an upward and forward rotation. It was demonstrated that there is a traction point between ANS and the center of the nasal cavity which would produce an anterior displacement of the maxillary complex without any rotation. When a downward force that was perpendicular to the palatal plane was employed, the response varied, depending on the loading point. If it was in the incisor region, the maxillary complex rotated downward and backward. If the loading point was in the distal aspect of the first permanent molar, the whole maxilla was pulled downward without any rotation. T. M. Graber
The Dental Specialties
in General
Practice
Alvin L. Morris, Harry N. Bohannan, and Daniel Casullo Philadelphia, 1983. W. B. Saunders illustrated, index. Price, $65.00
Company.
711 pages,
This volume is fittingly dedicated to a great educator, Lester W. Burket, and is intended to provide a compilation, under one cover, of specialty techniques that rightfully belong in the hands of enlightened, progressive, and conscientious general practitioners. It attempts to determine and describe the most common needs and to develop a text that is practical, useful, and applicable to everyday practice. Indeed, since all of the editors have been involved in advanced dental education, it could be categorized as “continuing education. ” For example, it is ideal as a text for general practice residents. The list of contributing authors is impressive. Louis Ripa discusses the prevention of dental caries in practice. The chapter of pedodontics is authored by Milton Houpt. Alvin Morris’s oral medicine chapter is short but well done. An excellent chapter on diagnosis and treatment planning in general practice by Daniel Casullo is beautifully organized and makes excellent reading for any dentist, whether a GP or specialist. The periodontics chapter by D. Walter Cohen and Norman Stoller recognizes the important role played by this aspect of dentistry in general practice and covers it well. The same is true for the endodontics chapter by Leif Tronstad. Henry Fields and William Proffit have done a very comprehensive chapter on orthodontics, showing how to form bands, place brackets, etc. The objectives of this chapter are to present diagnostic and treatment methods that can be employed in general practice and to give a general background of all orthodontic proce-
Reviews and abstracts
ment, and community dental health. Most of the illustrations are good, although some of the Kodachrome intraoral views that have been converted to black and white are washed out. Bibliographies are generally quite adequate at the end of each chapter. Production details are excellent, with good binding and paper quality, readable type, etc. There are a number of good pedodontic texts, but this certainly is one of the top-rung contributions that any practicing pedodontist would want on his shelf. T. hf. Graber
271
perimposition of tracings in longitudinal cephalometric analyses and offered a 70% improvement in accuracy over an observation period of one year. When the observation period was increased, a slight but significant reduction in precision was noted. The indications are that the maximum benefits may be expected for shortterm analyses of less than 3 years, and in particular for the x-coordinates of landmarks placed farther away from the cranial base. Nevertheless, photographic subtraction makes optimum use of image detail and thus offers significant improvements in the precision and reliability of radiographic cephalometric analysis. T. M. Graber
Photographic Subtraction Craniofacial Analysis
in
John Stuart McWilliam J. Dento-Maxi&-Facial
Radiol.,
Suppl.
4, 1983
The use of roentgenographic cephalometrics as a diagnostic tool in orthodontics is universally established as an aid both in diagnosing and in assessing growth and/or effects of orthodontic treatment. Orthodontic journals have published more cephalometric studies than in any other single area. Recently, however, a number of authors have questioned the reliability of such analyses. The aim of the present study was to determine whether or not photographic subtraction, in combination with direct digitizing of the films for the computer, could significantly reduce the errors encountered in craniofacial analysis. The author describes a general approach for evaluating digital measurements and describes how random and systematic errors can be detected and quantified. The latter can then be compensated for by suitable calibration of incoming data, whereas digitizing represents the optimal precision of the measuring system and can be used to follow aging of the instrument. A procedure for marking radiographs with four fiducial points is described and evaluated. This allows individual coordinate systems to be defined in order to facilitate duplication of landmark registration, addition of new landmarks to existing data, and definition of film orientation following superimposition procedures. The technique of photographic subtraction is applied to a study of condylar position. Acrylic indices were used to lock the mandible in centric relation during radiographic registrations. The analysis offered the most reliable results when bilateral instead of a onehanded pushback of the mandible was done prior to making of the radiograph. Evidence points to some posterior rotation of the mandible with this technique, however. Photographic subtraction was compared with su-
Aspectos de la Actividad Odontologica Durante el Conflict0 de las Malvinas Roberto Orlando Stvrtecky Revista
Assoc.
Odontol.
Argentina
71: 113-116,
1983
During the Anglo-Argentine conflict in the Malvinas (Falkland Islands), there was an interforce hospital in Puerto Argentino in which forty-five professionals and forty-four assistants rendered their services. Two of the assistants were dentists-one from the army and one from the air force. Three thousand fifty consultations for various types of pathosis were performed during peacetime. Then, with initiation of hostilities, there were 630 warassociated wound cases; 1,200 patients were sent to the hospital and 729 treatment procedures were carried out. Forty of these involved maxillofacial and dental complications and trauma. The most frequent cases were those due to shrapnel, bomb, or missile wounds. Following cessation of hostilities and during the imprisonment period, 69 treatment procedures were performed in Mount St. Edmund. They were of a dental nature and were performed with instruments and supplies that were provided by the British. T. M. Graber
Correction of the Measured Values Produced by the Mandibular Kinesiograph for the Analysis of Jaw Movement Around the Rest Position Satoshi Adachi, Keijiro Miyamoto, Masafumi Tsuchiya, Kenmi Yoshida, Kenji Takada, Yasuhiro Kakiuchi, Masaharu Kohbayashi, and Mamoru Sakuda J. Jpn.
Orthod.
Sot. 42: 297-306,
1983
The purpose of this study was to describe a new method for correction of the distorted original data obtained from the mandibular kinesiograph (MKG), to
272
Reviews and abstracts
Am. 1. Orthod. March 1984
analyze jaw movement quantitatively within a small range around the mandibular postural resting position, and to assess the reliability of this method. In order to investigate the amount of distortion involved in the MKG data, a parallel-sliding system was developed and connected with a three-dimensional digitizer (Gradicon) which was connected by an aluminum rod, in turn, to the magnet centered in the MKG sensor array. This assembly then was capable or registering the true X-Y-Z coordinates of the magnet’s position. The original MKG data were recorded directly by reading a digital tester at each of the magnet’s 168 positions, distributed at regular intervals with a range ofminus2toplus2mminX,minus2toplus lOinY, and 0 to minus 10 in Z coordinates. The formula for the correction, expressed by a dual equation of the second degree, was arrived at by inversely converting the equation which represents the distortion of the measured value received from the MKG. Then the true coordinates were compared to both the distorted original coordinates and the logically corrected coordinates for each dimension. The results showed that the distorted MKG data were sufficiently corrected to reduce the error to as small as 0.1 to 0.2 mm, and that this correction method had a good reliability for studying the jaw movements within a limited space around the mandibular postural resting position. T. M. Graber
An Experimental Study of the Displacement of the Maxillary Complex, Produced by Extraoral Forward Traction Toshiaki Tanabe, Kenji Suginome, Yasuhiko Yoshida, and Sadahiko Nlshiguchi J. Jpn.
Orthod.
Sot. 42: 322-335,
1983
While much of Class III therapy is directed toward the mandible, there is an increasing use of extraoral traction to the maxilla in skeletal Class III cases where there is manifest maxillary or midface deficiency. The precise nature of the effects of this type of extraoral traction to the maxilla have not been sufficiently studied as yet, so that the desired direction of pull, the amount of force, and the maxillary response can be determined ahead of time. Six dried human skulls were used for this study, to provide a model for a two-dimensional assessment of the maxillary complex and neighboring bones under varying vectors of maxillary traction in the horizontal and vertical directions. Ten loading points were set up on the model to assess the moving phase under extraoral traction.
When a dominantly forward extraoral traction force was applied, changing the loading point from the incisor area to the molar region, the maxillary complex exhibited an upward and forward rotation. It was demonstrated that there is a traction point between ANS and the center of the nasal cavity which would produce an anterior displacement of the maxillary complex without any rotation. When a downward force that was perpendicular to the palatal plane was employed, the response varied, depending on the loading point. If it was in the incisor region, the maxillary complex rotated downward and backward. If the loading point was in the distal aspect of the first permanent molar, the whole maxilla was pulled downward without any rotation. T. M. Graber
The Dental Specialties
in General
Practice
Alvin L. Morris, Harry N. Bohannan, and Daniel Casullo Philadelphia, 1983. W. B. Saunders illustrated, index. Price, $65.00
Company.
711 pages,
This volume is fittingly dedicated to a great educator, Lester W. Burket, and is intended to provide a compilation, under one cover, of specialty techniques that rightfully belong in the hands of enlightened, progressive, and conscientious general practitioners. It attempts to determine and describe the most common needs and to develop a text that is practical, useful, and applicable to everyday practice. Indeed, since all of the editors have been involved in advanced dental education, it could be categorized as “continuing education. ” For example, it is ideal as a text for general practice residents. The list of contributing authors is impressive. Louis Ripa discusses the prevention of dental caries in practice. The chapter of pedodontics is authored by Milton Houpt. Alvin Morris’s oral medicine chapter is short but well done. An excellent chapter on diagnosis and treatment planning in general practice by Daniel Casullo is beautifully organized and makes excellent reading for any dentist, whether a GP or specialist. The periodontics chapter by D. Walter Cohen and Norman Stoller recognizes the important role played by this aspect of dentistry in general practice and covers it well. The same is true for the endodontics chapter by Leif Tronstad. Henry Fields and William Proffit have done a very comprehensive chapter on orthodontics, showing how to form bands, place brackets, etc. The objectives of this chapter are to present diagnostic and treatment methods that can be employed in general practice and to give a general background of all orthodontic proce-