Relationship between morphological change of nasomaxillary complex and nasal respiratory function following to maxillary protraction

1994 Fiscal Year Final Research Report Summary

• Project/Area Number: 05454558
• Research Category: Grant-in-Aid for General Scientific Research (B)
• Allocation Type: Single-year Grants
• Research Field: 矯正・小児・社会系歯学
• Research Institution: Health Sciences University of Hokkaido
• Principal Investigator: ISHII Hideshi Health Sciences University of Hokkaido, School of Dentistry, Professor, 歯学部, 教授 (80001965)
• Co-Investigator(Kenkyū-buntansha): KOBAYASH Hiroki Health Sciences University of Hokkaido, School of Dentistry, Assistant, 歯学部, 助手 (70244861) ; TAKEUTI Makoto Health Sciences University of Hokkaido, School of Dentistry, Assistant Professor, 歯学部, 講師 (00143595)
• Project Period (FY): 1993 – 1994
• Keywords: Maxillary protraction / Chincap / Resistance of nasal of airway

Research Abstract

The purpose of this investigation was to clarify the effects of maxillary protraction in the the following three point ; (1) the difference of morphological and histological changes according with the difference of direction for the traction. (2) adaptaion of nasopharyngeal soft tissue to the maxillary skeletal changes during and after the traction. (3) relationship between the change of resistance of nasal airway and the morphological change during the experience.
For (1) : according to the cephalometric analysis, in the conventional direction of protraction, upper dental arch had moved mesially with counter clockwise rotation of the occlusal plane. In the skeletal change, forward movement as well as counterc lockwise rotation of the palatal plane was shown. Especially the distal part of the palatal plane moved downward. In the mandible, major change was not shown in spite of the lingual inclination of the incisors. For the animals protacted antero-inferiorly from the center of resista nce of the maxilla, forward movement of the maxillary complex with superior movement of upper occlusal plane and palatal plane. And, palatal plane did not rotate clockwisely. For (2) : In the thickness of the soft tissue on the plate, there was no difference between the two groups, and there was no pathological changes. Also antero-posterior opening of the transverse palatine suture was seen in the two groups. In the animals protracted antero-inferiorly from the center of resistance, absorbtion lacuna were seen on the superior and inferior plane of the suture. And they were also seen on the bone surface of nasal floor. For (3) : To measure the resistance of nasal airway of the monkey, it was shown that comparatively stable measurement could be obtained with active anterior method. With the differences of direction and degree of palatal movement, changing pattern on the resistance of nasal airway. That is, in the monkeys protracted conventionally, the resistance of nasal airway decreased, however, in the animals protracted antero-inferiorly from the center of maxillary resistance, it tended to increase. This fact shows that respiratory function can be changed following to the change of nasal volume with maxillary protraction. And it is thought to give an useful suggestion to the clinical aspect of orthodontics.