PubMed · 6575947
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
J R Jarabak. 1983. Open Bite. Skeletal morphology.. https://doi.org/10.1007/bf01997308
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
This retrospective study examines the therapeutic changes during the buccal segment retraction phase of treatment in 25 children with mild Class II, Division 1 malocclusions and for whom distalization of buccal teeth was the treatment of choice. Where significant mandibular retrognathia was diagnosed clinically, a functional treatment approach was indicated, and these children were not included in this study. Therapy was carried out with an upper removable expansion appliance and extraoral traction. It will be shown in Part II of the investigation that a full unit of buccal segment retraction can be expected, with a combination removable appliance/headgear technique.
One of the goals of early treatment of Class III malocclusion with maxillary expansion and protraction headgear is to significantly improve the dentofacial profile. The objectives of the present study were to determine (1) the interrelationships of the soft tissue and dentoskeletal profiles after maxillary expansion and protraction headgear treatment and (2) which cephalometric variables could contribute to an accurate prediction of the protraction effect on the soft tissue profile. Lateral cephalometric radiographs of 20 consecutively treated Class III patients (10 males, 10 females) by protraction headgear were included in this study. Their ages at the start of protraction headgear treatment ranged from 6 to 11 years, with an average of 8.1 +/- 2.1 years. None of the patients had previous orthodontic treatment. For each patient, the first lateral cephalogram was taken 6 months before the initiation of headgear treatment (T0), and the second radiograph at the start of treatment (T1). Therefore (T1-T0) represented 6 months of growth with no treatment. A third radiograph was taken 6 months after start of treatment (T2). In this way, (T2-T1)-(T1-T0) represented the effect the result of appliance therapy alone and each subject served as his/her own control. A computerized cephalometric analysis was used including variables assessing sagittal and vertical relationships of skeletal and soft tissue profiles, incisal relationships, soft tissue thickness, and lip structure. Data were analyzed by means of paired t tests, Pearson's product-moment coefficient correlation, and multiple regression analyses. The results showed significant improvements in dentofacial profile after 6 months of maxillary protraction. The skeletal and soft tissue facial profiles were straightened and the posture of the lips was improved. The normal incisal relationship (overjet) that was achieved had a significant impact on the soft tissues overlying both upper and lower incisors resulting in better lip competence and posture. Significant correlations were found between changes in the sagittal relationships of skeletal and soft tissue profiles in both the maxilla and the mandible (p < 0.05). The forward movement of the maxilla was accompanied by a corresponding forward movement of the soft tissue profile at 50% to 79% of the hard tissue. In the mandible, the downward and backward movements of the soft tissues were equivalent to 71% to 81% of the corresponding hard tissues. The lack of high r square values in the multiple regression analyses reflected a low prediction value for the maxillary variables, but moderately high prediction value for the mandibular variables that could be used in preorthopedic treatment planning. This study showed that significant dentoskeletal changes and improvements in dentofacial profile resulted from 6 months of treatment with maxillary expansion and protraction.
Plagiocephaly is a descriptive term that connotes an asymmetrically oblique or twisted head. Such cranial dysmorphology has a number of etiologies, the most common of which are unicoronal synostosis, unilambdoid synostosis, and plagiocephaly without synostosis. Use of the term plagiocephaly in the literature is often ambiguous in that at times it is used inclusively for all etiologies while at other times it is used exclusively as a synonym for unicoronal synostosis. Although differentiation by physical examination among unicoronal synostosis, unilambdoid synostosis, and plagiocephaly without synostosis usually is possible for an experienced observer, inexperienced observers often have difficulty making an anatomically accurate diagnosis even with the assistance of conventional skull radiographs. High-resolution CT scans, including three-dimensional osseous surface re-formations, have become a standard element in the evaluation of craniofacial anomalies in many centers. We hypothesized that the three major etiologies of plagiocephaly could be unambiguously differentiated by means of endocranial three-dimensional CT osseous surface re-formations. Archival pretreatment CT data on 15 unicoronal synostosis, 4 unilambdoid synostosis, and 15 plagiocephaly without synostosis patients were reviewed to define, qualitatively and quantitatively, the characteristics of the endocranial base morphologies for each group; in addition to visual dysmorphology specific to each group, there was a statistically significant difference in the angle of deviation from the midlines of the anterior and posterior cranial fossae among unicoronal synostosis, unilambdoid synostosis, and plagiocephaly without synostosis. Four radiologists experienced in reading images of craniofacial anomalies were oriented to the group characteristics and then instructed to perform differential diagnosis for each of the 34 patients using only the endocranial three-dimensional CT images. The raters were blind to all other clinical and diagnostic information. The raters correctly diagnosed unicoronal synostosis. Errors were made in differentiation of unilambdoid synostosis and plagiocephaly without synostosis. These errors resulted from the raters' reliance on image inspection rather than quantitation of anteroposterior fossae midline angulation. Such quantitation unambiguously differentiated between unilambdoid synostosis and plagiocephaly without synostosis in the "error" cases. The endocranial base dysmorphology of patients with plagiocephaly is etiology-specific for unicoronal synostosis, unilambdoid synostosis, and plagiocephaly without synostosis. Three-dimensional CT endocranial base images can assist differential diagnosis of plagiocephaly.