Orthodontic Phase Research Articles

Periodontal status of mandibular incisors following excessive proclination A study in adults with surgically treated mandibular prognathism

The present study was undertaken to examine whether excessive proclination of mandibular incisors results in gingival retraction. In patients with surgically treated mandibular prognathism, 29 with more than 10° proclination of mandibular incisors and 33 with minimal change in incisor inclination during presurgical orthodontic phase were selected. A total of 21 and 19 patients, respectively, could meet for a clinical follow-up examination including Visible Plaque Index, Gingival Bleeding Index, probing pocket depth, and length of supracrestal connective tissue attachment. Study models and intraoral color slides were also made. The mean postoperative times at this examination were 7.8 (SD 2.5) and 8.1 (SD 2.8) years, respectively. Clinical crown height was measured on the study models taken before and after appliance therapy, at the 3-year postoperative control (check) and at the follow-up examination. The number of teeth with recession was determined from the color slides taken at the same intervals; the thickness of the symphysis was measured on the cephalograms taken before treatment. The results demonstrated significantly more increase in clinical crown height and significantly more teeth developing recession both during appliance therapy and during the period from removal of appliance to the 3-year postoperative control in the patients with excessive proclination than in the patients with minimal change in incisor inclination. The correlation coefficient between width of symphysis and increase in clinical crown height in patients with excessive proclination was statistically significant. Only minimal changes were observed from 3 years postoperatively to the follow-up examination. No differences in clinical measurements were observed between the groups and bone dehiscences were not found.

Social-demographic differences and perceptions of lingual and conventional orthodontic patients: J. Albino, L. Gallo, L. Tedesco, L. Green, and J. CunatState University of New York at Buffalo (From J Dent. Res. 63: 254, 1984)

This investigation examined the relationship of postorthodontic treatment relapse to crestal alveolar bone support and root resorption. Thirty-six persons having completed the retention phase of orthodontics at least 10 years earlier were divided into two groups based on the amount of relapse crowding of the mandibular anterior teeth. Eighteen subjects (relapse group) exhibited 2 mm or more of mandibular anterior relapse crowding and 18 subjects (nonrelapse group) exhibited no mandibular anterior relapse crowding. At time of recall, full-mouth series of periapical and bitewing radiographs were obtained as well as lateral cephalometric films to allow comparison with similar lateral cephalometric films obtained at pretreatment and retention time points. The radiographs were examined to assess three parameters: root resorption, crestal alveolar bone levels, and changes in the position and angulation of the maxillary incisors. The subjects in the relapse group had undergone longer periods of treatment and exhibited a greater prevalence of root resorption; they also displayed significantly greater crestal alveolar bone level distances, indicating greater loss of bone support than that observed in the nonrelapse group. The distances that teeth were translated seemed to affect the extent of root resorption and crestal bone loss with smaller amounts of tooth translation seemingly more prone to demonstrate tissue loss. The findings of this investigation suggest there may be a relationship between orthodontic relapse and the parameters of increased root resorption and decreased crestal alveolar bone levels.

The change in American Board of Orthodontics Phase III requirements

The change in American Board of Orthodontics Phase III requirements

Function-The Neglected Phase of Orthodontics

Abstract No Abstract Available. Read before the Edward H. Angle Society of Orthodontia, Silver Anniversary meeting, Chicago, November, 1955.

Effects of maxillary bite plane therapy in orthodontics

This clinical report describes the simultaneous use of functional and fixed appliances to modify the pattern of dentofacial development and align teeth in preparation for prosthodontic habilitation of a growing child with hypohidrotic ectodermal dysplasia. The treatment objective was to create a more favorable starting point for the prosthodontic phase of habilitation by improving the sagittal and vertical skeletal relationships and facial esthetics. This was accomplished through growth modification with functional appliances conducted simultaneously with eruption of maxillary and mandibular molars, dental arch expansion, alignment, and space management using fixed orthodontic appliances. Orthodontic retention was accomplished by means of removable partial dentures. A second phase of orthodontics conducted closer to the age of skeletal maturation will aim at definitive tooth alignment in preparation for dental implant-supported restorations.

A survey on the use of the guide plane

Questionnaires were sent to seventeen leading orthodontists of the nation. Thirteen replied. Seven of the thirteen answered the questions in detail. Six have also contributed viewpoints. Of the thirteen who replied, nine use the guide plane, three do not, and one seldom uses it. These questions were entirely mechanical in character. However, several could not discard the scientific viewpoint. Of the three who do not use the guide plane, two, Doctors Joseph E. Johnson and James D. McCoy, use attachments of their individual designs on anterior bands. We can recognize that these plans stabilize anchorage of individual jaws, and as the jaws are developed, improved function brings about normal or near-normal depth of the lower part of the face without the use of the guide plane. Dr. John V. Mershon, the third contributor who does not use the guide plane, does not describe his plan whereby the use of this appliance is not necessary. On the question of mechanical cause of open-bite during treatment the majority opinion is that improper manipulation rather than incorrect appliance is responsible. The mechanical cause brings about a tipping of the molars. This tipping can be avoided by the use of the labial appliances properly stabilized, either by bands carrying attachments or by ligating to the anterior teeth. From these opinions we would gather that properly stabilized labial appliances make the use of the guide plane unnecessary and prevent open-bite. However, the experiences of many of us have shown ready correction of posterior relation in both protrusion and retrusion without the use of the guide plane. We have also seen these conditions respond only after the guide plane was used. Then, in a few instances the use of the guide plane produced no result at all. There are differences of opinions on the subject of bone change. One claim is that the only change is in the alveolar process, while other opinions are that changes involve other areas. The terms “bite block,” “bite plane” and “guide plane” show a difference of opinion as to the correct name for the appliance while one contributor finds objection to the metal framework, but uses one of “vulcanite or similar material.” There was an appeal by one contributor for better nomenclature. While the scientific phase of orthodontics is most important, the mechanical side is not insignificant. Proper education in the basic principles in the dental curriculum, thus laying a better foundation for a better understanding of orthodontic problems by the orthodontists of the future, is essential. In conclusion I want to thank the contributors for their valuable comments. Without their cooperation this survey would not have been possible.

A Modern Concept of Orthodontic Diagnosis

This case report describes the treatment of a 33-year-old white man who had a skeletal Class III and dental Class II subdivision malocclusion caused by a retrognathic maxilla, with severe maxillary crowding, a highly placed maxillary left canine, mild mandibular crowding, and a bilateral posterior crossbite. Treatment was performed with a modified surgery-first approach, which included a short presurgical alignment phase for the correction of the significant maxillary crowding while controlling the incisal angulation, followed by LeFort I maxillary advancement surgery. The short presurgical orthodontic phase aimed at eliminating the anterior dental interferences before the maxillary advancement, and the use of the inherent increased bone turnover in the postsurgical phase helped to reduce the total orthodontic treatment time to 12 months. Pleasing esthetic results and a good functional occlusion were achieved.