Anthony A. Gianelly

The use of magnets to move molars distally.

Repelling magnets, which were anchored to a modified Nance appliance cemented on the first premolars, were activated against the maxillary first molars to move them distally. Eighty percent of the space created represented distal movement of the first molars.

Japanese NiTi coils used to move molars distally

Japanese NiTi superelastic coils, exerting 100 gm of force, were compressed against the maxillary first molars and moved the molars distally 1 to 1.5 mm/month. Anchorage was obtained with a modified Nance appliance cemented onto the first premolars in conjunction with a fixed appliance.

Distal movement of the maxillary molars.

Molars can be moved distally approximately 1 mm/month with little to no patient cooperation by using intraarch compressed 100 gm NiTi coils or 100 gm looped NiTi wires against the molars supported by a removable modified Nance appliance. When the molars are moved posteriorly by these intraarch mechanisms, anchorage loss occurs and produces an increase in overjet that is generally within acceptable limits. Although molars can be moved posteriorly at any age, an advantageous treatment time is the late mixed dentition.

A universal direct bonding system for both metal and plastic brackets

Abstract A new system of direct bonding has been described, and a step-by-step procedure as utilized at the present time has been outlined. Changes are occurring rapidly in the technique, and these changes will bring a greater percentage of success. Now in progress are basic studies of an electron scanning analysis of the NuvaSeal junction and the enamel and of the adhesive and NuvaSeal. Other studies will determine the effect of NuvaSeal application on the sheen on the enamel surface after removal of the NuvaSeal preparation. Clinical use may be somewhat empirical until these and other basic studies have been cempleted.

A comparison of Class II treatment changes noted with the light wire, edgewise, and Fränkel appliances.

The purpose of this study was to determine if selected cephalometric changes noted in groups of growing patients with Class II, Division 1 malocclusions treated with the Fränkel function regulator (FR-2), the edgewise technique, and the light-wire (Begg) mechanism were different and characteristic of a specific technique. To this end, the changes in the SNA, SNB, N-S-Gn, and the SN-GoGn angles, face height (N-M), the anterior movement of pogonion, and the annualized mandibular growth increment (AR-Gn) in a group of patients treated with the FR-2 were compared to the changes noted in similar groups of patients treated by the edgewise technique and the light-wire mechanism. The methods used to compare the groups were an analysis of variance and a discriminant analysis. A reduction in the SNA angle was observed in all groups. It was -0.37 degrees with light wire treatment, -0.60 degrees with Fränkel appliance use, and -1.47 degrees with edgewise therapy. The SNB angle increased in all three groups, ranging from 0.29 degrees in the edgewise group to 0.56 degrees in the Fränkel group. In the light-wire group it was 0.34 degrees. The N-S-Gn angle in the Fränkel group remained essentially the same (0.06 degrees), while in the light-wire and edgewise groups it increased 0.81 degrees and 0.82 degrees. The SN-GoGn angle opened slightly in all groups, ranging from a low of 0.46 degrees with Fränkel therapy to 0.58 degrees with edgewise treatment to 1.25 degrees with the use of the light-wire appliance.(ABSTRACT TRUNCATED AT 250 WORDS)

Extraction vs Nonextraction: Arch Widths and Smile Esthetics

Dental casts of 30 patients treated with extraction and 30 patients without extraction of four first premolars were randomly selected to determine changes in arch width as a result of treatment. Arch widths were measured from the cusp tips of the canines, premolars, and molars. Posttreatment arch widths were also measured in the midline at a constant arch depth from the most labial surfaces of the incisors. Standardized frontal photographs of the face taken during smiling of 12 extraction- and 12 nonextraction-treated subjects were evaluated. Fifty laypersons judged the esthetics of the smiles. Intercanine width increased less than one mm in both groups, and there was no difference between the two groups. The interpremolar and intermolar distance in both arches decreased significantly from 0.53 to 0.95 mm in the extraction sample, whereas the interpremolar and intermolar widths increased significantly from 0.81 to 2.10 mm in the nonextraction sample. When arch widths of both groups were measured from the most labial surfaces of the teeth at a constant depth, the average arch width of both arches was significantly wider in the extraction sample (1.8 mm wider in the mandible and 1.7 mm wider in the maxilla). The mean esthetic score and the number of teeth displayed during a smile did not differ between the groups. The results indicate that arch width is not decreased at a constant arch depth because of extraction treatment, and smile esthetics are the same in both groups of patients.

Mandibular Growth, Condyle Position and Fränkel Appliance Therapy

A statistical evaluation of condyle position and mandibular length changes in 10 patients after one year of Fränkel appliance therapy, finding the condyle forward on the eminence in 4 of them. Large variations were found in mandibular growth, with no significant difference from the means of patients treated with the Edgewise appliance.

The use of the lingual arch in the mixed dentition to resolve incisor crowding

In the mixed dentition, arch length preservation, maintaining the leeway space, can often provide adequate space to resolve lower incisor crowding. Yet the frequency of this occurrence is not known. To obtain this information, lingual arches were placed in the mandibular arches of 107 consecutive mixed dentition patients with incisor crowding to preserve arch length and make the leeway space available to resolve the crowding. Arch length decreased only 0.44 mm whereas the intercanine, interpremolar, and intermolar dimensions increased between 0.72 and 2.27 mm. There was adequate space to resolve the crowding in 65 (60%) of the 107 patients. If perfect arch length preservation had occurred, there would have been adequate space to resolve the crowding in 73 (68%) of the 107 patients. The correlation between leeway space and tooth size-arch size discrepancy was only 0.44.

Force-induced changes in the vascularity of the periodontal ligament

The application of a force to a tooth can stimulate the process of alveolar bone resorption by creating areas of pressure in the attachment apparatus.l-s Although the cellular mechanisms may be the same, two forms of resorption (frontal and undermining) have been described and related, in part, to the magnitude of the applied force.1-5 The distinction is based on the pattern of bone removal. For example, frontal resorption usually stimulated by the application of “light” forces, consists of resorption of the plate of alveolar bone adjacent to the area of the periodontal membrane under pressure. In contrast, with “heavy” forces, there is no bone-resorptive activity at the immediate site of pressure. Rather, resorption occurs above and below the pressure site and in the marrow spaces next to the alveolar plate. As the resorption progresses, the bone at the pressure area is undermined from the bordering sides and is the last segment of bone to be removed.” The association between force application and bone resorption has led to the supposition that the type of resorption is related to the integrity of the periodontal membrane which, in turn, is dependent on the vascularity of the membrane.‘e8 Theoretically, forces exerting pressures which do not occlude the vascular network of the ligament stimulate the cells in the area under pressure to initiate the process of frontal resorption. In contrast, only undermining resorption follows the application of forces which obliterate the vascularity, since the cytoarchitecture of the membrane is destroyed, possibly by anoxia.2-* Since vascular integrity is considered to be an indispensable aspect of membrane health and function and is, therefore, an important, if not decisive, factor in determining the pattern of bone resorption that follows force application, the present study was undertaken to examine the relationship between force, vascular patency, and alveolar bone resorption.

Crowding: timing of treatment.

The late mixed dentition stage of development, after the eruption of the first premolars, is a favorable time to start treatment to resolve crowding. This protocol offers the clinician choices. If nonextraction treatment is preferable, arch length preservation can provide the space for alignment in approximately 75% of all patients with crowding. If extraction treatment is indicated, the first premolars are available.