Adolescent patients' experience with the Carriere distalizer appliance.

AIM: To examine adolescent patients' experience with the Carriere Distalizer Appliance (CDA) and compare it with that of the Forsus Fatigue Resistant Device (FFRD). MATERIALS AND METHODS: A survey was administered to 42 patients treated with the CDA and 70 patients treated with the FFRD. Amount of time required to become accustomed to the appliance, how many patients experienced side effects as well as the degree of discomfort were explored. RESULTS: The overall experience with the device was significantly better for the CDA group than for the FFRD group. Both groups felt that delivery and removal of the appliance was quick and easy, the appliance was noticeable to some extent, and the majority became accustomed to it within two weeks with a maximum of one month. In general, associated discomfort and effects on daily life and activities were less for the CDA group than for the FFRD group. Side effects decreased over time for both groups, often more so for the CDA group. The major side effects experienced by the CDA group were difficulty eating and sore teeth, and these improved significantly over time. Soreness from the appliance rubbing on the cheek or lip was significantly less for the CDA group. CONCLUSION: The CDA appears to be more comfortable, offers a more positive overall experience, and has fewer negative comfort-related side effects compared to FFRD.

A longitudinal evaluation of extraction versus nonextraction treatment with special reference to the posttreatment irregularity of the lower incisors.

A tendency exists in contemporary orthodontics to pursue a completely non-extraction philosophy. Moreover, it has been shown that the extraction versus non-extraction debate is still with us. Controversy exists as to which treatment decision will eventually lead to orthodontic stability. It is thus imperative to conduct investigations on long-term changes of the dentition in both treatment regimens. The present study serves as an example of such a longitudinal study. A random sample, inclusive of both extraction and non-extraction treatments, was examined with respect to long-term stability and an assessment was made as to whether one treatment option favors success over the other. It was concluded that the correct initial treatment choice will not only lead to correction of the malocclusion, but will also ensure clinically acceptable stability with no significant differences between extraction and non-extraction treatments.

Adaptation of the bioprogressive philosophy to use brackets with .022" slots.

The Bioprogressive orthodontic treatment philosophy is traditionally associated with the use of brackets that have .018" slots. Proponents of the Bioprogressive philosophy suggest this slot configuration largely because they believe that lighter wires provide force levels that are within the biological limits of the periodontal support system. At the same time, the principles of orthodontic anchorage advocated by the Bioprogressive philosophy depend on careful torque control of both molar and anterior teeth. It is possible and sometimes advisable to use wires designed for use in brackets with .018" slots, in brackets with .022" slots. Under these circumstances, the thinner wires may not provide sufficient control over torque moments to develop the required degree of molar anchorage. This article suggests that with the use of certain wires, and with minor modifications to the shapes of arches, that the use of brackets with .022" slots need not conflict with many of the important principles of orthodontic treatment advocated in the Bioprogressive philosophy.

The relationship between ortho head posture and head posture measured during walking.

Murphy, Preston, and Evans recognized the dynamic nature of head posture and developed instrumentation capable of measuring and recording this posture in a continuous manner. The aim of the current project was to use the newly developed instrumentation to determine whether the difference is statistically significant between the mean natural head ortho posture, measured in a controlled manner, and the mean dynamic head posture obtained during 5 minutes of walking activity in an experimental situation. The mean ortho head posture and the mean walking head posture were measured in each of 30 men. The differences between these two sets of mean head postures were statistically significant (p < or = 0.05). In 23 persons, the mean walking head posture was tipped backward relative to the mean natural head ortho position.

An evaluation of two methods used to determine the centre of gravity of a cadaver head in the sagittal plane.

A suitable method to locate the centre of gravity of the head is not available at present. Precise location of that centre will help in the understanding of aspects of cranial balance and what effect skeletal changes, following for example orthognathic surgery, may have on head posture. The objective of this research was to use a mechanical (empirical) method, based on accepted laws of physics, to determine the centres of gravity of cadaver heads in the sagittal plane and to compare these positions with those generated by a computer programme. The two methods located the centre of gravity in the same region but at a different position in each corresponding head. These differences were statistically significant (p < 0.01). It is likely that improved computer techniques together with modern three dimensional imaging methods will be able to locate the centre of gravity of a head in a living subject.

A longitudinal evaluation of the anterior border of the dentition.

Posttreatment changes of orthodontically treated dentitions are inherent to every orthodontic practice. Various studies have documented the ideal posttreatment dental and cephalometric norms that could pertain to stable long-term occlusal results. Clinically, changes in these parameters are often observed as mandibular incisor crowding. The purpose of this study was to evaluate the longitudinal changes in certain variables representing the anterior border of the dentition. Eighty-eight white subjects were assessed regarding stability of the dentition after edgewise orthodontic treatment. (44% nonextraction, 56% extraction) The following variables in proximity of the anterior limit of the dentition (overbite, overjet, mandibular arch length, upper and lower incisor position, Little irregularity index) were assessed and correlated with each other. The data were subjected to descriptive statistics, the Friedman test for significant changes and pairwise comparisons, and the Spearman correlation test. Mandibular intercanine width was not significantly altered during treatment, but although not significantly, p > 0.05 did decrease beyond the original measurement during posttreatment evaluation (mean 7 years after treatment). The other variables influenced by the orthodontic manipulation were all within normal ranges and remained stable. The arch length decreased significantly (p < 0.05) during the entire evaluation period and was the only variable not stable. It was concluded that: (1) sound treatment leads to attainment of ideal occlusal parameters, (2) mandibular intercanine expansion could lead to failure of results, (3) arch length change plays a major role in causing irregularity of mandibular incisors after treatment, and (4) patient education regarding posttreatment orthodontic changes is imperative.

The development of instrumentation for the dynamic measurement of changing head posture.

Cranial posture and its possible relationship to the morphology of the skull has been studied in some detail, as have the relationships between cranial posture and such functions as respiration and jaw movements. To date, cranial posture has been assessed mainly with techniques that give static interpretations of the angular relationships between intracranial and extracranial reference lines. The present project was undertaken to develop a system of instruments capable of the continuous measurement and recording of cranial posture for extended periods of time. A number of aspects of this system were tested. The results indicate that the experimental array of instruments measures head posture accurately over a defined range of cranial movement. This new technique should make it possible to measure cranial posture in a more dynamic and physiologic manner.

Provision of "comprehensive dental care" in various dental schools.

The purpose of this survey was to solicit information about comprehensive dental care (CDC) programs in various dental schools. Seventy-four schools responded to a questionnaire that sought information about a range of topics pertaining to CDC. The 19 questions used were categorized under the following headings: implementation and success, physical nature of clinics, staffing, and student involvement. The diverse nature of the responses is thought to be an expression of differing philosophies and of the presence of numerous constraints to the introduction of CDC. The various approaches to CDC make it very difficult to gauge the relative merits of the many systems reported. It appears from this study that departments will continue to play an important role in preparing students to participate in CDC programs and that it would be safer to introduce students to CDC during their final year of study.

Provision of "comprehensive dental care" in various dental schools.

The purpose of this survey was to solicit information about comprehensive dental care (CDC) programmes in various dental schools. Seventy-four schools responded to a questionnaire which sought information about a range of topics pertaining to CDC. The 19 questions used were categorized under the following headings: implementation and success; physical nature of clinics; staffing; and, student involvement. The diverse nature of the responses is thought to be an expression of differing philosophies and of the presence of numerous constraints to the introduction of CDC. The various approaches to CDC make it very difficult to gauge the relative merits of the many systems reported. It appears from this study that departments will continue to play an important role in preparing students to participate in CDC programmes and that it would be safer to introduce students to CDC during the final year of study.

Fluctuating dental asymmetry as a measure of odontogenic canalization in man.

Fluctuating odontometric asymmetry was evaluated in 202 Lengua Indians and in 125 contemporary caucasoids using Euclidean map analyses, rescaled asymmetry values, and Naperian logarithmic transformations. Both populations showed bimodal distributions of canalizing ability, with significantly more Lengua Indians being less well canalized. Student t-tests indicated that significant interpopulation differences in rescaled asymmetry values centered around maxillary mesiodistal dimensions. Analyses of variance failed to show significant levels of sexual dimorphism in the magnitude of asymmetry for both populations. It is concluded that even in a relatively stress-free population, there exist some individuals who are less well canalized than others. When a population is subjected to elevated levels of parasitic and nutritional stress, the number of less-well-canalized individuals increases significantly.

Fluctuating odontometric asymmetry in the Lengua Indians of Paraguay.

Fluctuating dental asymmetry was evaluated as an indicator of environmental stress in a group of 202 living Lengua Indians from the Paraguayan Chaco area. Older, less accultured individuals were shown to be significantly more asymmetric than younger individuals who had been increasingly exposed to western foodstuffs and medicine. Lengua Indians demonstrated similar levels of asymmetry to another preliterate group, the Ticuna Indians of Columbia, but were found to be significantly more asymmetric than contemporary caucasoids. Similar patterns of asymmetry in both arcades for males and females were confirmed by analyses of variance and by Spearman's rank-order correlation coefficients. Partitioning variation in the degree of asymmetry by arcade, dimension and tooth revealed significant differences in the effects of tooth and arcade only: asymmetry was greater in the maxilla and greater in the more distal teeth within each morphogenic class.

On the non-existence of compensatory tooth size interaction in a contemporary human population.

Compensatory tooth size interactions between early and later developing teeth within the same tooth class were empirically evaluated in a sample of 125 study casts of Caucasoid children. Mean buccolingual and mesiodistal diameters for first and second molars, pre-molars, and incisors were calculated, and those first developing teeth that were either larger of smaller than the mean were identified. Pearsonian correlation coefficients and chi-square tests revealed highly significant positive correlations between smaller of larger early developing teeth and their later developing neighbors. This total lack of compensatory tooth size interaction was also confirmed when outsized teeth (larger of smaller than one standard deviation from the mean) were used. Similar results were obtained when tooth size was corrected for arcade length, hence allowing for the rejection of Sofaer's model of compensatory tooth size interaction.

Occluso-cranial correlates of attrition in a preliterate population. A cross-sectional study.

Evaluation of dental casts of 202 living Lengua Indians from Paraguay finds progressive reduction in overjet with age, but no Class III or indication of altered relationship of mandible to cranial base.

Restitution of facial form in a patient with hemifacial microsomia. A case report.

Hemifacial microsomia involves unilateral underdevelopment of the ear, mandible and associated structures. This report describes an approach to early surgical restoration of function to improve growth, illustrated with a case report.