Histological suture changes following retraction of the maxillary anterior bone segment after corticotomy

Abstract

By cephalometric and dental cast analyses, the effects of corticotomy in combination with 45-50 days retraction of the maxillary anterior segment were evaluated in five female Japanese monkeys (Macaca fuscata). In addition, microscopic changes of the related sutures were examined. According to the analyses of the dental casts, the retraction of the maxillary anterior segment in the experimental group was increased when compared with that of the control group. There was no change in occlusal molar relationship. The cephalometric analysis revealed that the "Point A" and "Metal Implant" on the mid-sagittal site between the upper central incisors in the experimental group showed more pronounced retraction than that in two untreated control animals. These results were histologically evaluated by changes of the suture structure: irregularity of functional arrangement of component cells and fibers, an increase in number of cells, resorption and formation of bone, and an enlargement of the suture width. Resorption of tooth roots and alveolar bone, and irregularity of the periodontal ligament were observed. In general, these histological changes appeared more extensive in the control specimens compared with the experimental specimens. The osseous histological changes were mainly observed in the compact bone area, while in the spongy bone area of both control and experimental specimens only minimal changes occurred. These results demonstrated the efficacy of combining a corticotomy procedure with retraction of the maxillary anterior bone segment by an orthodontic force.

Treatment outcome analysis of speedy surgical orthodontics for adults with maxillary protrusion

“…15,16 The application of heavy forces in maxillary retraction was studied in an animal model with monkeys by Kawakami et al 19 and Yoshikawa 20 in Japan. They reported that a corticotomized maxillary segment could be effectively retracted using a heavy force of 400 g per side without damage to the intraoral or extraoral soft tissues, inferring that the orthopedic force after a perisegmental corticotomy could clinically apply to humans.…”

“…More importantly, speedy surgical orthodontics can induce a bone-bending effect by applying the heavy orthopedic force against a palatal temporary skeletal anchorage device (Fig 1). 15,16,19,20 Recently, temporary skeletal anchorage devices such as orthodontic miniscrews and miniplates have replaced extraoral anchorage devices that rely significantly on patient compliance. [21][22][23] Advances in temporary skeletal anchorage device designs and applications have enabled orthodontists to use absolute anchorage and heavy forces without biomechanical side effects during orthodontic therapy.…”

Response of Zygomaticomaxillary Suture to Experimental Malocclusion in Rats

“…To date, various methods have been used to apply external stress to sutures surrounding the oral cavity to investigate their histomorphological changes. These methods include mechanical expansion [Miyawaki and Forbes, 1987;Southard and Forbes, 1988], protraction force [Nanda and Hickory, 1984;Kawakami et al 1996], transplantation [Oudhof and Markens, 1982], incisor excision [Sukekawa and Itoh, 1995], and the use of bite blocks [Melsen et al, 1995]. Occlusal forces also influence sutures [Forbes and Al-Bareedi, 1986;Hinton, 1988].…”

Severe bimaxillary protrusion with adult periodontitis treated by corticotomy and compression osteogenesis

“…According to Kawakami et al's animal study, after coroticotomy, there was an increase in the number of cells, the irregularity of functional arrangement of cells and fibers, the amount of bone resorption and apposition, and the width of sutures. 25 Changes were seen mostly in the cortical layer, while minimal changes were noticeable in spongeous bone. The medullary bone around anterior teeth can be easily bent by heavy retraction force if the cortical layer between the basal and alveolar bones is interrupted.…”

“…The objective was about a four mm setback and three mm intrusion. In the maxilla, the level of orthopedic force was taken from Suya, 19 Kawakami et al 25 and Yoshikawa 28 's theory, a force of 500 to 900 grams per side was applied to the C-plate and C-tube. Fukanaga et al have tried to retract the anterior dentition in patients exhibiting bone loss using skeletal anchorage.…”