- Email: [email protected]
Relationships between sesamoid calcification and facial growth
Volume 85 Number 6
Reviews and abstracts
appliance, preferably fixed, such as a quad helix type, probably should be placed in the early mixed dentition if expansion plate wear cannot be assured. T. M. Graber
An Investigation Into the Initial Discomfort Caused by Placement of an Archwire M. L. Jones Eur.
J. Orthod.
648-54.
1984
Thirty patients completed a discomfort index card for the first 16 days following the placement of fixed appliances. Six patients had 0.016 inch arch wires for Begg appliances; twenty-four had 0.015 inch multistranded arch wires in 0.022 inch slots of an edgewise appliance. There were ten male and twenty female patients ranging in age from 11.5 to 30.2 years. The recorded score for the degree of discomfort and the analgesic requirement was made on a sessional basis. It was found that a number of patients suffered severe discomfort over the first few days, eleven scoring at least one severe discomfort session and twelve a moderate discomfort session. Only two patients were free of pain. The majority of discomfort recording occurred over the first 8 days, although the most severe scores were mostly within the first 3 days. Those scoring severe discomfort sessions usually had the worst pain at night, and this correlated well with when the analgesics were required most. Those patients recording mild discomfort (five) had this discomfort evenly distributed throughout the day. There was a statistically significant difference in the discomfort index of adolescents under 16 years of age and adults over 16 years of age, with greater initial discomfort in the adults. No sexual dimorphism was encountered. Discomfort experience was quite low for placement of subsequent arch wires, except where torque was employed.
533
underwent surgical fossa displacement by a combined effect of altered growth of the neurocranium and artificial craniosynostosis. A control group did not undergo surgery. Ten control and ten experimental animals were sacrificed at 50 days for macroscopic studies. Of twenty-one measurements made on the dried skulls, fourteen were used for comparison of the two groups, As a reaction to an increased posterior migration of the glenoid fossa, the mandible appeared to grow longer and the growth of the condylar cartilage increased, as compared to the controls. The resorptive process at the anterior aspect of the condyle appeared more rapid than the apposition at the posterior aspect. In spite of the increased condylar growth, the condyles were located more anteriorly and inferiorly in relation to the fossa from 5 days postoperatively onward. However, no differences in intermaxillary relationships were observed between the control and the experimental animals during any phase of the observation period. The present method seems useful for studying condylar growth. The results indicate that the condyle is adaptive to some extent to sagittal changes in the fossa, with resorptive responses greater than those of apposition. Since not only the condyle but also the glenoid fossa reacted to the provoked changes, it appears that the whole temporomandibular joint is constructed to ensure a functionally sufficient intermaxillary relationship. The findings that the intermaxillary relationship remained unchanged, despite the posteriorly displaced fossa, could conversely be interpreted to indicate that the tissues (for example, the muscles) connecting the mandible to contiguous structures are more important than growth of the condyle in determining the sagittal intermaxillary relationship. T. M. Graber
T. M. Graber
Research abstracts Effect of Increased Posterior Displacement of the Glenoid Fossa on Mandibular Growth: A Methodological Study on the Rabbit Tuomo Eur.
Kantomaa
J. Orthod.
615-24,
1984
This award-winning essay, presented at the Fiftyninth Congress of the European Orthodontic Society, addresses an important subject-the role of the glenoid fossa position in the ultimate sag&al intermaxillary relationship. Eighteen lo-day and ten 5-day New Zealand rabbits
Relationships Calcification
Between Sesamoid and Facial Growth
L. Chmura Center for Human Growth and Development, Mich. (Supported through the Craniofacial Center for Human Growth and Development (From J. Dent. Res. 63: 163, 1984)
Ann Arbor, Group of the
Although prediction of facial growth is a major concern of the orthodontist planning treatment, the available methods for doing so are not reliable. There is evidence that calcification of the ulnar adductor sesa-
534
Am. J. Orthod. June 1984
Reviews and abstracts
moid bone (ASC) is a good predictor of the adolescent growth spurt in stature. There is also evidence linking the statural spurt with a facial spurt, and linking the facial spurt with ASC. Mandibular length and anterior facial height, both linear measures, are the dimensions most often associated with ASC. This study is designed to show relationships between ASC and facial growth, using a tensor analysis of growth and controlling explicitly for chronological age-a major confounding factor in conventional study designs. The results show a relationship signijcant at the 95% level between ASC and facial size change in males only. The direction of greatest size change difference approximated a line from Sella to Menton. No sig-
nificant size change was found for females, and no significant shape change relationship was found for either males or females. The results of this study do not provide much comfort to those wishing to use ASC to predict facial growth spurts. It has not been shown that ASC can be used to predict important attributes of spurts-onset, duration, and growth rate. Even if these could be accurately predicted, not all children manifest the spurts equally and different directions of facial growth manifest different spurts.
Local Factors Determine the Progeny Skeletoblasts In Vitro: Chondroblasts versus Osteoblasts
of
H. Silbermann Bone Cell Biology Section, NIDR, Bethesda, (From J. Dent. Res. 63: 167, 1984)
Md.
The mandibular condyles of fetal and neonatal mice and rats contain a layer of embryonic cells capable of differentiation to either chondroblasts or osteoblasts. Under normal functioning conditions in vivo, these ‘ ‘skeletoblasts ” differentiate to cartilage cells that subsequently contribute to endochondral bone formation. If, however, young condylar cartilages are transferred to subcutaneous sites or to in vitro organ culture systems these ‘ ‘skeletoblasts ” switch their differentiation pathway and develop into new osteoblasts. The latter synthesize and secrete type I collagen, fibronectin, osteonectin and bone-specific alkaline phosphatase. The newly formed osteoid undergoes mineralization. The de novo formation of new bone in vitro is a reproducible feature provided the tissue is cultured at the interface between the medium (MEM or BGJB) and the air (containing 5% CO,) above it. When condylar cartilages are cultured as submerged tissues within the
medium a larger portion of the skeletoblasts continue to differentiate to cartilage cells. The elaboration of new bone in vitro takes place when explants are placed on either millipore filters, collagen sponges or on demineralized bone. Autoradiography experiments indicate that the new bone cells originate in the skeletoblasts’ cell layer. The latter cells maintain their capacity to form new bone in vitro even in serum-free, hormonedefined medium. The above organ culture system provides a novel model for studies related to osteogenesis and chondrogenesis.
The Predictability of the Success Bite Plane Treatment
of the
Y. Kobayashi, Y. Takeda, and T. lshikawa Department of Prosthodonrics, Nippon (From J. Dent. Res. 63: 172, 1984)
Dental
Universiry,
Tokyo
The purpose of this experiment was to investigate the possibility of predicting the prognosis of the bite plane. The psychological tests of Cornell Medical Index-Health Questionnaire (CMI) and Manifest Anxiety Scale (MAS) were performed on 90 TMJ dysfunction patients who were divided into positive and negative groups. The muscle palpation score and the maximum jaw opening ability were used as the criteria for the success of the bite plane treatment. Twentyseven patients were treated with the Michigan splint and 63 with the anterior type bite plane. As a group both the maximum jaw opening ability and the palpation score had improved significantly after 2 weeks of the bite plane treatment. In the psychological tests, 58.8% had been classified as negative in both CMI and MAS tests, 15.6% had either one of the tests positive, and 25.6% had both positive. The first group showed significant improvements in both the palpation score and the jaw opening ability. The latter two groups also showed improvements but no significant differences were observed. Thus it was suggested that by applying the results of the CMI and MAS tests the prognosis of the bite plane
could
be predicted.
Effect of Splint Occlusal Guidance Masticatory Muscle EMG Activity
on
G. S. Graham and J. D. Rugh University of Texas Health Science Center, (From J. Dent. Res. 63: 172, 1984)
San Antonio
It has been reported (Williamson and Lundquist 1983) that cuspid guidance is necessary to decrease masticatory muscle activity in excursive movements; however, cuspid guidance was not compared with other
Reviews and abstracts
appliance, preferably fixed, such as a quad helix type, probably should be placed in the early mixed dentition if expansion plate wear cannot be assured. T. M. Graber
An Investigation Into the Initial Discomfort Caused by Placement of an Archwire M. L. Jones Eur.
J. Orthod.
648-54.
1984
Thirty patients completed a discomfort index card for the first 16 days following the placement of fixed appliances. Six patients had 0.016 inch arch wires for Begg appliances; twenty-four had 0.015 inch multistranded arch wires in 0.022 inch slots of an edgewise appliance. There were ten male and twenty female patients ranging in age from 11.5 to 30.2 years. The recorded score for the degree of discomfort and the analgesic requirement was made on a sessional basis. It was found that a number of patients suffered severe discomfort over the first few days, eleven scoring at least one severe discomfort session and twelve a moderate discomfort session. Only two patients were free of pain. The majority of discomfort recording occurred over the first 8 days, although the most severe scores were mostly within the first 3 days. Those scoring severe discomfort sessions usually had the worst pain at night, and this correlated well with when the analgesics were required most. Those patients recording mild discomfort (five) had this discomfort evenly distributed throughout the day. There was a statistically significant difference in the discomfort index of adolescents under 16 years of age and adults over 16 years of age, with greater initial discomfort in the adults. No sexual dimorphism was encountered. Discomfort experience was quite low for placement of subsequent arch wires, except where torque was employed.
533
underwent surgical fossa displacement by a combined effect of altered growth of the neurocranium and artificial craniosynostosis. A control group did not undergo surgery. Ten control and ten experimental animals were sacrificed at 50 days for macroscopic studies. Of twenty-one measurements made on the dried skulls, fourteen were used for comparison of the two groups, As a reaction to an increased posterior migration of the glenoid fossa, the mandible appeared to grow longer and the growth of the condylar cartilage increased, as compared to the controls. The resorptive process at the anterior aspect of the condyle appeared more rapid than the apposition at the posterior aspect. In spite of the increased condylar growth, the condyles were located more anteriorly and inferiorly in relation to the fossa from 5 days postoperatively onward. However, no differences in intermaxillary relationships were observed between the control and the experimental animals during any phase of the observation period. The present method seems useful for studying condylar growth. The results indicate that the condyle is adaptive to some extent to sagittal changes in the fossa, with resorptive responses greater than those of apposition. Since not only the condyle but also the glenoid fossa reacted to the provoked changes, it appears that the whole temporomandibular joint is constructed to ensure a functionally sufficient intermaxillary relationship. The findings that the intermaxillary relationship remained unchanged, despite the posteriorly displaced fossa, could conversely be interpreted to indicate that the tissues (for example, the muscles) connecting the mandible to contiguous structures are more important than growth of the condyle in determining the sagittal intermaxillary relationship. T. M. Graber
T. M. Graber
Research abstracts Effect of Increased Posterior Displacement of the Glenoid Fossa on Mandibular Growth: A Methodological Study on the Rabbit Tuomo Eur.
Kantomaa
J. Orthod.
615-24,
1984
This award-winning essay, presented at the Fiftyninth Congress of the European Orthodontic Society, addresses an important subject-the role of the glenoid fossa position in the ultimate sag&al intermaxillary relationship. Eighteen lo-day and ten 5-day New Zealand rabbits
Relationships Calcification
Between Sesamoid and Facial Growth
L. Chmura Center for Human Growth and Development, Mich. (Supported through the Craniofacial Center for Human Growth and Development (From J. Dent. Res. 63: 163, 1984)
Ann Arbor, Group of the
Although prediction of facial growth is a major concern of the orthodontist planning treatment, the available methods for doing so are not reliable. There is evidence that calcification of the ulnar adductor sesa-
534
Am. J. Orthod. June 1984
Reviews and abstracts
moid bone (ASC) is a good predictor of the adolescent growth spurt in stature. There is also evidence linking the statural spurt with a facial spurt, and linking the facial spurt with ASC. Mandibular length and anterior facial height, both linear measures, are the dimensions most often associated with ASC. This study is designed to show relationships between ASC and facial growth, using a tensor analysis of growth and controlling explicitly for chronological age-a major confounding factor in conventional study designs. The results show a relationship signijcant at the 95% level between ASC and facial size change in males only. The direction of greatest size change difference approximated a line from Sella to Menton. No sig-
nificant size change was found for females, and no significant shape change relationship was found for either males or females. The results of this study do not provide much comfort to those wishing to use ASC to predict facial growth spurts. It has not been shown that ASC can be used to predict important attributes of spurts-onset, duration, and growth rate. Even if these could be accurately predicted, not all children manifest the spurts equally and different directions of facial growth manifest different spurts.
Local Factors Determine the Progeny Skeletoblasts In Vitro: Chondroblasts versus Osteoblasts
of
H. Silbermann Bone Cell Biology Section, NIDR, Bethesda, (From J. Dent. Res. 63: 167, 1984)
Md.
The mandibular condyles of fetal and neonatal mice and rats contain a layer of embryonic cells capable of differentiation to either chondroblasts or osteoblasts. Under normal functioning conditions in vivo, these ‘ ‘skeletoblasts ” differentiate to cartilage cells that subsequently contribute to endochondral bone formation. If, however, young condylar cartilages are transferred to subcutaneous sites or to in vitro organ culture systems these ‘ ‘skeletoblasts ” switch their differentiation pathway and develop into new osteoblasts. The latter synthesize and secrete type I collagen, fibronectin, osteonectin and bone-specific alkaline phosphatase. The newly formed osteoid undergoes mineralization. The de novo formation of new bone in vitro is a reproducible feature provided the tissue is cultured at the interface between the medium (MEM or BGJB) and the air (containing 5% CO,) above it. When condylar cartilages are cultured as submerged tissues within the
medium a larger portion of the skeletoblasts continue to differentiate to cartilage cells. The elaboration of new bone in vitro takes place when explants are placed on either millipore filters, collagen sponges or on demineralized bone. Autoradiography experiments indicate that the new bone cells originate in the skeletoblasts’ cell layer. The latter cells maintain their capacity to form new bone in vitro even in serum-free, hormonedefined medium. The above organ culture system provides a novel model for studies related to osteogenesis and chondrogenesis.
The Predictability of the Success Bite Plane Treatment
of the
Y. Kobayashi, Y. Takeda, and T. lshikawa Department of Prosthodonrics, Nippon (From J. Dent. Res. 63: 172, 1984)
Dental
Universiry,
Tokyo
The purpose of this experiment was to investigate the possibility of predicting the prognosis of the bite plane. The psychological tests of Cornell Medical Index-Health Questionnaire (CMI) and Manifest Anxiety Scale (MAS) were performed on 90 TMJ dysfunction patients who were divided into positive and negative groups. The muscle palpation score and the maximum jaw opening ability were used as the criteria for the success of the bite plane treatment. Twentyseven patients were treated with the Michigan splint and 63 with the anterior type bite plane. As a group both the maximum jaw opening ability and the palpation score had improved significantly after 2 weeks of the bite plane treatment. In the psychological tests, 58.8% had been classified as negative in both CMI and MAS tests, 15.6% had either one of the tests positive, and 25.6% had both positive. The first group showed significant improvements in both the palpation score and the jaw opening ability. The latter two groups also showed improvements but no significant differences were observed. Thus it was suggested that by applying the results of the CMI and MAS tests the prognosis of the bite plane
could
be predicted.
Effect of Splint Occlusal Guidance Masticatory Muscle EMG Activity
on
G. S. Graham and J. D. Rugh University of Texas Health Science Center, (From J. Dent. Res. 63: 172, 1984)
San Antonio
It has been reported (Williamson and Lundquist 1983) that cuspid guidance is necessary to decrease masticatory muscle activity in excursive movements; however, cuspid guidance was not compared with other