Biochemical and Clinical Assessments of Segmental Maxillary Posterior Tooth Intrusion

Abstract

Objective. To compare chondroitin sulphate (CS) levels around maxillary second premolars, first molars, and second molars between the unloaded and the loaded periods and to measure the rates of intrusion of maxillary posterior teeth during segmental posterior tooth intrusion. Materials and Methods. In this prospective clinical study, 105 teeth (from 15 patients exhibiting anterior open bite and requiring maxillary posterior tooth intrusion) were studied. Competitive ELISA was used to detect CS levels. Dental casts (during the unloaded and loaded periods) were scanned, and posterior tooth intrusion distances were measured. Results. During the unloaded period, the median CS levels around maxillary second premolars, first molars, second molars (experimental teeth), and mandibular first molars (negative control) were 0.006, 0.055, 0.056, and 0.012 and during the loaded period were 2.592, 5.738, 4.727, and 0.163 ng/μg of total protein, respectively. The median CS levels around experimental teeth were significantly elevated during the loaded period. The mean rates of maxillary second premolar and first and second molar intrusion were 0.72, 0.58, and 0.40 mm/12 weeks, respectively. Conclusions. Biochemical and clinical assessments suggested that the segmental posterior tooth intrusion treatment modality with 50 g of vertical force per side was sufficient. Trial Registration. The study is registered as TCTR20170206006.

Optimal percentage of buccal to palatal intrusive force ratio for pure vertical maxillary first molar intrusion: A finite element study

“…(31) Despite the fact that some studies did not clearly specify it, the reported force magnitudes for upper molar intrusion ranged from 150 g (13)(14)(15) to 500 g (20,(32)(33)(34)(35)(36)(37)(38)(39) . In the present study, FEA employed a total applied total molar intrusive force of 200 grams (100 g buccal and 100 g palatal), which was consistent with earlier studies (20,(40)(41)(42) which concluded that; upper molar intrusion forces should be between 100 and 200 g. which also consistent with the finding of Furthermore, Kato and Kato (43) claimed that a force of 100 g was inadequate for posterior segment intrusion and that raising the force to 300 g allowed for progressive intrusion keeping in mind, this study considering posterior segment no single molar intrusion.…”

“…The force magnitude effective in posterior or intrusion had subjected to much debate in previous numerous studies as stated by Foot R et al 2014 (31) ; Tasanapanont J et al 2017 (40) used 50 gm per side; others used a force ranged from 100 to 200 gm for posterior segment intrusion (20,(41)(42)(43) ; arrange for 200-400 gm was suggested by . Kravitz ND et al 2007 (27) ; others used a heavier force range from 400 to 500 gm (31,38,39,51) , So in the present study we tested a force started by 75 gm buccal and 75 gm palatal.…”

Force magnitude as a variable in maxillary buccal segment intrusion in adult patients with skeletal open bite:

“…17 Different authors used variable forces and reported different amounts of intrusion. The minimum intrusive force used was 50 g per side, 21 while the more commonly used forces ranged between 100 and 200 g. 13,14,22 On the other hand, Kato and Kato 23 suggested that a force of 100 g was insufficient for posterior segment intrusion and stated that increasing the force up to 300 g permitted progressive intrusion. Later, a range of 200 to 400 g for segmental posterior intrusion was suggested.…”

The number of osteoblasts and osteoclasts in hypofunctional teeth during orthodontic tooth movement in rats

“…3 Open bite malocclusion occurs when maxillary and mandibular teeth are not in contact. 4 Hypofunctional teeth cause atrophic changes in the periodontal ligament, a decrease in the number of periodontal fibers and blood vessels, and the periodontal space's narrowing. Periodontal space's narrowing occurs due to the apposition of the alveolar bone by an increase in Transforming Growth Factor β (TGFβ), causing tooth elongation.…”