Labial root torque: Effect on the maxilla and incisor root apex

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Reviews and abstracts Am. 1. Orihod. Dentofac. Orthop. fme 1987 tified significant maturation levels at which greater treat- ment changes were achieved. This study confirms that the greatest skeletal cor- rection was obtained during periods of peak velocity of growth at Fishman’s skeletal maturational levels 4 to 7. In fact, mean SNA reduction, mean Lande’s angle reduction, and mean percent change Na to point A were twice as great during maturational levels 4 to 7 than at levels I to 3. Cervical headgear treatment during mat- ruational levels 8 to 11 showed only 25% reduction as compared with peak velocity of growth (levels 4 to 7). Comparison of treatment among persons with dif- fering stages of skeletal maturation indicated that if possible headgear therapy should be initiated at the beginning of the adolescent growth spurt and continued through peak velocity growth if one is to obtain optimal apical base positioning. This study confirms the fact that skeletal age as determined by the hand-wrist ra- diograph is more accurate than chronologic age in de- termining an optimal period when cervical headgear can be used with the greatest efficiency. ffects of Rapid Maxillary Expansion e Deviated Nasal Septum-An tigation Using the Frontal Rochester, New York: Eastman Dental Center, 1986 The study was designed to determine whether the rapid maxillary expansion (RME) procedure would im- prove a deviated septum. Twenty-seven patients who bad a deviated bony nasal septum and had had RME were investigated using serial frontal radiographs. The sample was divided into high and low expansion groups, the amount of expansion achieved being de- termined by the measured increase in the Ricketts inter J-point distances. A matched control sample consisted of ten patients who had not undergone RME. The ra- diographs were traced and analyzed using Harvold’s “‘x-line” method as horizontal and vertical baselines. Anatomic landmarks were digitized and entered into a microcomputer to calculate linear distances of septal deviation from the established midline. The findings were as follows: I.. A small (0.76 t 0.14 mm) though statistically highly significant (P = 0.0002) decrease oc- curred in septal deviation in the subjects who had undergone RME. 2. There was a slight increase in septal deviation in the control sample, but a highly signi (P = 0.0002) overall mean difference between the two groups of 1.1 mm. 3. No consistent effect on the amount of deflection of the most inferior part of the septum to or away from the midline was noted. 4. No significant difference between the amount of septal straightening in the high or low expansion groups was observed; some subjects showed sig- nificant septal straightening despite rni~irn~ or- thopedic expansion. Labial Root Torque: Effect on the and Incisor Root Apex Bruce Goldin Rochester, New York: Eastman Dental Center, 1966 The purpose of this study was to dete~i~e the effectiveness of labial root torque on anterior naso- maxillary development. Quantification was ma angular and linear changes in point A and any concom- itant incisor root resorption. The study was divided into two parts: (1) to determine the anatomic configuration of the premaxillary region using lam~nagra~by on skulls and (2) to use the morphologic landmarks found in part 1 to assess the development of the nasomaxillary complex in maxillary retrusive patients. Eight dry hu- man skulls were used in part 1. Data compiled from lateral headplates, midsagittal plane laminagraphs, and midincisor laminagraphs were com~~ed for anatomic differences. Results indicate that there was a tendency for Downs point A to be depicted further anterior in the lateral cephalogram than the actual midsagittal plane structure. An incisor-apex-related point A was defined and found to be posterior and inferior to Downs point A. The clinical study used I7 maxillary retrusive pa- tients aged 8 .O to 15.7 years, having been treated be- tween 0.3 1 and 3.70 years. Control subjects were se- lected from 30 persons whose lateral head films were previously traced from the files of the Charles Bingham Bolton study. Results indicate that during the first phase of orthdontic treatment with labial root torque, initial record to first serial lateral cephalogram, having a mean treatment period of 0.63 year over a total age period of 1.5 years, a greater rate of and percentage advance- ment of Downs point A was produced when compared to normal growth. The skeletal convexity increased, whereas normal growth straightened the profile. Incisor point A advanced at a greater rate and percentage change than Downs point A, suggesting that treatment caused

Transcript of Labial root torque: Effect on the maxilla and incisor root apex

Reviews and abstracts Am. 1. Orihod. Dentofac. Orthop. fme 1987

tified significant maturation levels at which greater treat- ment changes were achieved.

This study confirms that the greatest skeletal cor- rection was obtained during periods of peak velocity of growth at Fishman’s skeletal maturational levels 4 to 7. In fact, mean SNA reduction, mean Lande’s angle reduction, and mean percent change Na to point A were twice as great during maturational levels 4 to 7 than at levels I to 3. Cervical headgear treatment during mat- ruational levels 8 to 11 showed only 25% reduction as compared with peak velocity of growth (levels 4 to 7).

Comparison of treatment among persons with dif- fering stages of skeletal maturation indicated that if possible headgear therapy should be initiated at the beginning of the adolescent growth spurt and continued through peak velocity growth if one is to obtain optimal apical base positioning. This study confirms the fact that skeletal age as determined by the hand-wrist ra- diograph is more accurate than chronologic age in de- termining an optimal period when cervical headgear can be used with the greatest efficiency.

ffects of Rapid Maxillary Expansion e Deviated Nasal Septum-An tigation Using the Frontal

Rochester, New York: Eastman Dental Center, 1986

The study was designed to determine whether the rapid maxillary expansion (RME) procedure would im- prove a deviated septum. Twenty-seven patients who bad a deviated bony nasal septum and had had RME were investigated using serial frontal radiographs. The sample was divided into high and low expansion groups, the amount of expansion achieved being de- termined by the measured increase in the Ricketts inter J-point distances. A matched control sample consisted of ten patients who had not undergone RME. The ra- diographs were traced and analyzed using Harvold’s “‘x-line” method as horizontal and vertical baselines. Anatomic landmarks were digitized and entered into a microcomputer to calculate linear distances of septal deviation from the established midline.

The findings were as follows: I.. A small (0.76 t 0.14 mm) though statistically

highly significant (P = 0.0002) decrease oc- curred in septal deviation in the subjects who had undergone RME.

2. There was a slight increase in septal deviation

in the control sample, but a highly signi (P = 0.0002) overall mean difference between the two groups of 1.1 mm.

3. No consistent effect on the amount of deflection of the most inferior part of the septum to or

away from the midline was noted. 4. No significant difference between the amount of

septal straightening in the high or low expansion groups was observed; some subjects showed sig- nificant septal straightening despite rni~irn~ or- thopedic expansion.

Labial Root Torque: Effect on the and Incisor Root Apex Bruce Goldin Rochester, New York: Eastman Dental Center, 1966

The purpose of this study was to dete~i~e the effectiveness of labial root torque on anterior naso- maxillary development. Quantification was ma angular and linear changes in point A and any concom- itant incisor root resorption. The study was divided into two parts: (1) to determine the anatomic configuration of the premaxillary region using lam~nagra~by on skulls and (2) to use the morphologic landmarks found in part 1 to assess the development of the nasomaxillary complex in maxillary retrusive patients. Eight dry hu- man skulls were used in part 1. Data compiled from lateral headplates, midsagittal plane laminagraphs, and midincisor laminagraphs were com~~ed for anatomic differences. Results indicate that there was a tendency for Downs point A to be depicted further anterior in the lateral cephalogram than the actual midsagittal plane structure. An incisor-apex-related point A was defined and found to be posterior and inferior to Downs point A.

The clinical study used I7 maxillary retrusive pa- tients aged 8 .O to 15.7 years, having been treated be- tween 0.3 1 and 3.70 years. Control subjects were se- lected from 30 persons whose lateral head films were previously traced from the files of the Charles Bingham Bolton study. Results indicate that during the first phase of orthdontic treatment with labial root torque, initial record to first serial lateral cephalogram, having a mean treatment period of 0.63 year over a total age period of 1.5 years, a greater rate of and percentage advance- ment of Downs point A was produced when compared to normal growth. The skeletal convexity increased, whereas normal growth straightened the profile. Incisor point A advanced at a greater rate and percentage change than Downs point A, suggesting that treatment caused

Volume 91 Number 6

Reviews and ab~~~ac~~ !fi

a larger dentoalveolar effect than midsagittal basal bone, When treatment was extended to 1.57 years over a mean total age period of 2.5 years, similar changes were found but at a reduced rate. Overall mean incisor tooth length loss was 0.9 mm/year and apical root re- sorption at about 1.4 mm/yr or 15.62%/year. The major portion of this resorption occurred during the initial phase of treatment. The effects of sex and age were not found to have any correlation to the amount of apical root loss.

Longitudinal Cephalometric Study of bular Asymmetry and Condylar plasia and Hypoplasia

Rochester, New York: Eastman Dental Center, 1986

The purpose of this study was to investigate the relationship between mandibular asymmetries and the morphology and growth of the mandible using serial cephalometric records. The subjects consisted of four persons whose initial ages were from 9 to 10 years. Three of these subjects demonstrated obvious clinical mandibular asymmetries; the fourth subject appeared to be symmetric. Forty-five degree oblique radiographs were used, and the entire mandible was traced on these views. Records available for the subjects covered time spans of 9, 10, 11, and 22 years. Linear measurements of the mandibular body, ramus, and condyle were eval- uated. Examination of ramal heights indicated differing patterns of growth in the asymmetric persons. Differ- ences between right and left sides may exist at an early age, yet remain fairly constant with growth; in other instances a progressive increase in the disparity between right and left may occur. In a clinically normal person, differences between right and left do occur yet remain consistently small throughout adolescent growth. How- ever, in one subject discrepancies did not become ev- ident until approximately 25 years of age and became progressively more severe, although prior to this oc- currence the magnitude of left-right differences was very small. Area measurements, although somewhat

variable, demonstrated progressive increases in con- dylar area in some asymmetric persons as well as a slowly progressive decrease in condylar area in one instance.

A Comparison of Arthrog Joint Sound Analysis in T Internal Derangements J. Lawrence Hutta, Thomas W. Richard W. Katzberg, Ross Tall Mark A. Espeland Rochester, New York: Eastman Dental Center, 1986

Internal derangements of the temporoma~dibul~ joint (TMJ) are common and can be detected by ar- thrography, CT, or magnetic resonance imaging. Re- cently, it has been suggested that clicking sounds pro- duced during reducing displacements of the disc can be assessed for indices that may inexpensively and non- invasively establish a specific diagnosis. The purpose of this clinical investigation was to examine the pos- sibility that an analysis of TMJ sound power spectra can effectively separate abnormalities of the TMJ re- lated to variable degrees of disc displacement. Cate- gories of patients studied were as follows: symptomatic but arthrographically normal (SN), meniscal displace- ment with reduction (painful clicking of the TMJ [MDR]), and meniscal displacement without reduction (MD). Sounds were obtained prospectively on 47 joints before arthrographic examination using a digital steth- oscope that allows a computer-generated power spec- trum analysis. Our results indicate that the M had 4 times more energy above a frequ than either SN or MDR joints (P 0.001); test). A rating scale of the power spectrum waveforms was also used to examine differences between groups. The power spectra for 71% of the MDR joints were classified as “smooth” as compared with only 10% of the SN and 5% of the MD TMJs (P 0.0005; chi-square test). This study strongly supports the sugestion that an analysis of TMJ sounds can provide an effective screen- ing examination.