Effects of relapse forces on periodontal status of mandibular incisors following orthognathic surgery
ABSTRACT In this case-control study, the relationship between the relapse forces and periodontal changes in the mandibular incisor region were investigated following orthognathic surgery.
Mucogingival and alveolar changes in 36 subjects with mandibular prognathism were analyzed by clinical and roentgenographic methods just before mandibular setback surgery and 7.4 months postoperatively. The results were compared to two control groups: 36 subjects with no orthodontic history and 33 orthodontic patients. The mean age of the 105 subjects was 20.21 years.
The intergroup comparisons showed significant differences in all parameters, except for the plaque index and alveolar height measurements. By an incisor proclination of 3.3 mm and a tipping of +8.5 degrees (postoperative relapse: 0.8 mm and 0.14 degrees ), the surgery group revealed significant changes in single parameters of both alveolar height and sulcus depth measurements.
Compared to both control groups, the preoperative periodontal condition of the surgery patients was less acceptable than in the orthodontically treated patients, whereas subjects without braces presented the most ideal hygienic conditions. In the short term, the decompensation process prior to mandibular setback surgery did not affect periodontal structures significantly, and the current study did not find any negative effects of early postoperative relapse forces on the mandibular incisor area.
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- "We found no statistically significant difference for the mean change during decompensation for maxillary incisors between the Class III and Class II group, whilst the amount of decompensation achieved for the mandibular incisors for Class III patients was statistically significantly greater than in the Class II group. Interestingly, Potts et al. (5) found that most cases with retroclined incisors were not decompensated adequately prior to orthognathic surgery, whilst Ari-Demirkaya and Ilhan (17) identified that in 28% of patients with Class II malocclusion, the mandibular incisors were still protrusive at the time of surgery with angles greater than 99o. Proclination of incisors has been shown to be more achievable than retroclination (6) and our results would indicate that incisor decomensation in the mandible is more achievable than in the maxilla. "
ABSTRACT: Objectives: To quantify incisor decompensation in preparation for orthognathic surgery. Study design: Pre-treatment and pre-surgery lateral cephalograms for 86 patients who had combined orthodontic and orthognathic treatment were digitised using OPAL 2.1 [http://www.opalimage.co.uk]. To assess intra-observer reproducibility, 25 images were re-digitised one month later. Random and systematic error were assessed using the Dahlberg formula and a two-sample t-test, respectively. Differences in the proportions of cases where the maxillary (1100 +/- 60) or mandibular (900 +/- 60) incisors were fully decomensated were assessed using a Chi-square test (p<0.05). Mann-Whitney U tests were used to identify if there were any differences in the amount of net decompensation for maxillary and mandibular incisors between the Class II combined and Class III groups (p<0.05). Results: Random and systematic error were less than 0.5 degrees and p<0.05, respectively. A greater proportion of cases had decompensated mandibular incisors (80%) than maxillary incisors (62%) and this difference was statistically significant (p=0.029). The amount of maxillary incisor decompensation in the Class II and Class III groups did not statistically differ (p=0.45) whereas the mandibular incisors in the Class III group underwent statistically significantly greater decompensation (p=0.02). Conclusions: Mandibular incisors were decompensated for a greater proportion of cases than maxillary incisors in preparation for orthognathic surgery. There was no difference in the amount of maxillary incisor decompensation between Class II and Class III cases. There was a greater net decompensation for mandibular incisors in Class III cases when compared to Class II cases. Key words:Decompensation, orthognathic, pre-surgical orthodontics, surgical-orthodontic.Journal of Clinical and Experimental Dentistry 07/2014; 6(3):e225-9. DOI:10.4317/jced.51310
Conference Paper: Spectral shaping for the hearing impaired[Show abstract] [Hide abstract]
ABSTRACT: A method is presented for shaping the audio spectrum to improve intelligibility for the hearing impaired. Actual audiological data is used to design a finite impulse response digital filter using the frequency sampling method. Cubic spline interpolation is used to generate any number of frequency samples from the limited number available from the audiological dataSoutheastcon '96. 'Bringing Together Education, Science and Technology'., Proceedings of the IEEE; 05/1996
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ABSTRACT: Orthodontic treatment aims at providing an acceptable functional and aesthetic occlusion with appropriate tooth movements. These movements are strongly related to interactions of teeth with their supportive periodontal tissues. In recent years, because of the increased number of adult patients seeking orthodontic treatment, orthodontists frequently face patients with periodontal problems. Aesthetic considerations, like uneven gingival margins or functional problems resulting from inflammatory periodontal diseases should be considered in orthodontic treatment planning. Furthermore, in cases with severe periodontitis, orthodontics may improve the possibilities of saving and restoring a deteriorated dentition. In modern clinical practice, the contribution of the orthodontist, the periodontist and the general dentist is essential for optimized treatment outcomes. The purpose of this systematic review is to highlight the relationship between orthodontics and periodontics in clinical practice and to improve the level of cooperation between dental practitioners. Potentials and limitations that derive from the interdisciplinary approach of complex orthodontic-periodontal clinical problems are discussed.Journal of Oral Rehabilitation 02/2010; 37(5):377-90. DOI:10.1111/j.1365-2842.2010.02068.x · 1.68 Impact Factor