下顎骨前突之病患以矯正合併口內下頷支垂直截骨術後之移動變化評估

Evaluation of post-operative changes of orthodontic treatment combined with intraoral vertical ramus osteotomy

王脩然(Hsiu-Jan Wang)

指導教授 ： 蔡吉陽

臺北醫學大學/口腔醫學院/牙醫學系碩博士班/碩士(2013年)

https://doi.org/10.6831/TMU.2013.00090

摘要

骨性第三類型（Skeletal Class III）是臨床上常見的咬合不正類別，嚴重的骨性第三類患者通常伴有咀嚼和發音等功能異常，以及明顯的容貌缺陷，進而導致心理與社會關係障礙等問題。顏面特徵會隨著骨性變異嚴重程度而呈現輕度至重度凹臉型的外觀，患者除了美觀的因素外，通常求診原因包含：咀嚼障礙、發音問題、人際關係與心理因素等等。因此，在臨床上，對於骨性第三類型咬合不正患者，矯正與正顎手術合併的療程進而成為主流的治療趨勢。綜合矯正與手術之治療計畫，在療程前之確切的診斷與有效的預期術後之結果對於臨床醫師而言是不可或缺的。術前的考量包含：牙齒與顏面部的異常、術前矯正可達到齒列去代償的程度、手術中顎骨移動的範圍、術後預期可改善的顏面外觀等。

下顎骨前突之骨性三級異常病患通常以：（1）雙側下顎骨垂直支的矢狀面劈開術（Bilateral Sagittal Split Ramus Osteotomy，以下簡稱BSSO）或是（2）口內下頷枝垂直截骨術（Intraoral Vertical Ramus Osteotomy，以下簡稱IVRO）兩種手術方式進行處理。過去研究指出，由於口內下頷枝垂直截骨術（IVRO）相對於雙側下顎骨垂直支的矢狀面劈開術（BSSO）較不易造成下顎齒槽神經損傷[1]、術中出血量少[2]，以及顯著減少術後病患顳顎關節問題[3]，因此在考量病患術後預後與併發症風險等，口內下頷枝垂直截骨術（IVRO）是較為安全的手術方式。

過去文獻與研究中，對於雙側下顎骨垂直支的矢狀面劈開術（BSSO）術式與其術後顏面部外觀改變有較多探討，對於其術後穩定性也有較多研究。相較於雙側下顎骨垂直支的矢狀面劈開術（BSSO），對於口內下頷枝垂直截骨術（IVRO）在手術後輪廓改變與術後穩定型研究較少；此外，對於口內下頷枝垂直截骨術（IVRO）之術後組織變化大部分在於探討術前術後測顱分析值在水平前後（anteroposterior）方向的改變，較少有研究討論下顎骨在垂直方向的改變、下顏面高度的提升、下顎骨角的術後變化等。因此，本研究目的在探討因單純下顎骨前突之骨性三級咬合病患而至台北醫學大學附設醫院牙科部接受矯正合併口內下頷枝垂直截骨術（Intraoral Vertical Ramus Osteotomy）治療之患者，其手術前後顏面部輪廓與組織變化、下顎骨在術後的順時鐘旋轉、上下與前後顏面部高度之改變，以及下顎角開展度的改變，進而討論手術穩定性與週邊肌肉關係。

患者樣本皆於2009∼2012年間於台北醫學大學附設醫院牙科部完成全口矯正合併正顎手術治療。符合樣本有16位（男性8位，女性8位）因下顎骨前突之骨性三級異常咬合異常接受矯正及正顎手術治療之病患。病患平均年齡22.4歲（分布18.6∼26.4歲）。治療時間由18個月至36個月，平均治療時間24.4個月。研究資料選取範圍為病患在矯正治療前（T0）、及手術前矯正階段完成時（T1）、手術後六週顎間固定（intermaxillary fixation）拆除時（T2）、以及最終手術合併矯正療程結束後（T3）等四次時間點所拍攝之測顱X光片。治療前後組織特徵之差異以paired t test加以比較。

關鍵字

口內下頷支垂直截骨術 ； 順時鐘旋轉 ； 前牙開咬

並列摘要

Angle’s classification skeletal Class III occlusion is a type of malocclusion commonly observed among Asian patients. Depending on its severity, skeletal Class III patients are usually diagnosed with chewing and pronunciation dysfunction, facial asymmetry and concavity, and possibly mental and socio-psychological retardations. The degree of craniofacial defects and facial concavity vary among patients. The most typical chief complaint of patients and their reason for seeking treatment may be: chewing difficulties, pronunciation dysfunction, mental or social obstacles due to abnormal appearance. Therefore, the combination of orthodontic treatment with orthognathic surgery is now progressively considered a routine treatment protocol for patients diagnosed with severe skeletal Class III malocclusion. A panoramic and systematic treatment plan involving both the orthodontic and surgical aspects is of tremendous importance. Factors to consider at the pre-surgical orthodontic treatment stage include: the severity of dental and craniofacial abnormality, the extent of pre-surgical dental decompensation, the amount of necessary surgical setback and rotation, and the expected post-surgical outcome following the completion of orthodontic treatment and orthognathic surgery.

Severely prognathic patients generally require surgical mandibular setbacks in addition to orthodontic treatment in order to achieve an orthognathic and esthetic profile. Bilateral sagittal split ramus osteotomy (BSSO) and intraoral vertical ramus osteotomy (IVRO) are the two most commonly practiced surgical techniques in the correction of skeletal Class III mandibular prognathism. Past studies have proved that IVRO, in comparison to BSSO, has the advantages of decreased risks of neurovascular injuries, lower incidences of hemorrhaging, and fewer complaints of temporomandibular joint discomfort after surgery. Therefore, in consideration of improving surgical prognosis and minimizing post-operative complications, IVRO is more preferable in the treatment of skeletal Class III prognathic patients as it is proven to be a safer and more effective method of surgery.

Numerous studies have been done on post-surgical stability, morphological changes, and long-term relapses following BSSO. However, relatively few studies of the same regime have been focused on IVRO. Moreover, past researches on post-IVRO profile changes have mainly focused on alterations in the anteroposterior direction. Few studies have been designed to investigate the changes in vertical dimension, gonial angle and mandibular plane rotations. The purpose of this experiment, therefore, is to explore the facial and morphological adaptations in patients receiving orthodontic treatment combined with orthognathic surgery (IVRO). The particular changes of interest include: facial profile, vertical dimension, mandibular plane rotations, mandibular angle variations, surgical stability and its relation to surrounding musculature.

The sample population of patients under investigation was gathered from the Orthodontic Department in the Taipei Medical University Hospital, Department of Dentistry, from 2009~2012. All patients were diagnosed as skeletal Class III with severe mandibular protrusion, and therefore, required surgical orthodontic treatment. Number of patients assembled in this study were 16 (8 males and 8 females), average age was 22.4 years (range 18.6~26.4 years). In the period of this study, all patients have completed orthodontic treatment combined with orthognathic surgery (IVRO). Cephalometric data were collected at 4 different time points: prior to treatment (T0), pre-surgery and upon completion of pre-surgical orthodontic treatment (T1), at the removal of intermaxillary fixation 6 weeks after surgery (T2), and at the completion of treatment (T3). Cephalograms taken at the different time points were traced and analyzed. Paired t test was used to compare the mean differences in measurements on the cephalograms at each time interval.

並列關鍵字

IVRO ； clockwise rotation ； anterior openbite

參考文獻

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