成人单侧完全性唇腭裂双侧髁突的形态特点

doi:10.3969/j.issn.2095-4344.2015.24.010

摘要/Abstract

摘要：

背景：对单侧完全性唇腭裂患者进行正畸治疗，应首先了解其髁突形态的特点。
目的：探索成人单侧完全性唇腭裂患者双侧髁突形态的特点。
方法：收集临床单侧完全性唇腭裂患者和正常志愿者各25例，分别作为实验组和对照组，通过全颌曲面断层片，测量髁突上部高度、升支高度、髁突高度、髁突颈部宽度，并计算髁突上部高度/升支高度和髁突高度/髁突颈部宽度。
结果与结论：与对照组相比，实验组患者健侧和缺损侧髁突上部高度、髁突颈部宽度、髁突高度、髁突上部高度/升支高度减小(P < 0.05)，且髁突形态类型存在明显差异，但升支高度和髁突高度/髁突颈部宽度差异无显著性意义(P > 0.05)，且实验组患者健侧和缺损侧髁突上部高度、升支高度、髁突颈部宽度、髁突高度、髁突上部高度/升支高度、髁突高度/髁突颈部宽度以及髁突形态差异无显著性意义(P > 0.05)。说明成人单侧完全性唇腭裂患者呈现髁突短而颈部窄，髁突相对下颌升支短小的特点,这为临床上矫治单侧完全性唇腭裂患者提供临床依据。

中国组织工程研究杂志出版内容重点：干细胞；骨髓干细胞；造血干细胞；脂肪干细胞；肿瘤干细胞；胚胎干细胞；脐带脐血干细胞；干细胞诱导；干细胞分化；组织工程

关键词: 组织构建, 组织工程, 唇腭裂, 髁突, 全颌曲面断层片, 下颌, 正畸治疗, 先天性发育缺陷

Abstract:

BACKGROUND: The characteristics of condylar morphology should be first understood in patients with unilateral cleft lip and palate.
OBJECTIVE: To investigate the bilateral condylar morphology in adult patients with unilateral cleft lip and palate.
METHODS: This study included 25 patients with unilateral cleft lip and palate (study group), and 25 normal volunteers (control group). The upper condylar height, ramal height, condylar height and condylar width were measured on panoramic radiographs. The ratio of the upper condylar height to the ramal height and the ratio of the condylar height to the condylar width were calculated.
RESULTS AND CONCLUSION: Compared with the control group, upper condylar height, condylar width, condylar height and the ratio of the upper condylar height to the ramal height were reduced in the study group between the normal and affected sides (P < 0.05). Moreover, significant differences in condylar morphology were detected between the two groups. No significant difference in ramal height and the ratio of the condylar height to the condylar width was detected between the two groups (P > 0.05). No significant difference in upper condylar height, ramal height, condylar width, condylar height, the ratio of the upper condylar height to the ramal height, the ratio of the condylar height to the condylar width, and condylar morphology was detectable between the normal and affected sides in the experimental group (P > 0.05). These data show that adult patients with unilateral cleft lip and palate presented short condylar process and narrow neck, and the condylar process is shorter than ramus, which provides clinical evidence for patients with unilateral cleft lip and palate.

中国组织工程研究杂志出版内容重点：干细胞；骨髓干细胞；造血干细胞；脂肪干细胞；肿瘤干细胞；胚胎干细胞；脐带脐血干细胞；干细胞诱导；干细胞分化；组织工程

Key words: Cleft Lip, Cleft Palate, Mandibular Condyle, Orthodontics, Corrective

中图分类号:

R318

李增才，刘新强. 成人单侧完全性唇腭裂双侧髁突的形态特点[J]. 中国组织工程研究, 2015, 19(24): 3818-3823.

Li Zeng-cai, Liu Xin-qiang. Bilateral condylar morphology in adult patients with unilateral cleft lip and palate [J]. Chinese Journal of Tissue Engineering Research, 2015, 19(24): 3818-3823.

图/表（结果） 3

Quantitative analysis and clinical information of experimental subjects
All patients were involved in the final analysis, no loss. Flowchart of trials is displayed in Figure 2.

The age distributions in the two groups are shown in
Table 1. There was statistically insignificant difference between the male and female in condylar morphology^[32-35]. Therefore, data for both genders were pooled for analyses.
Condylar morphology
Descriptive statistics and comparison of upper condylar height, ramal height, condylar height, condylar width, the ratio of the upper condylar height to the ramal height and the ratio of the condylar height to the condylar width for the right and left sides in the control group are shown in Table 2. There was no statistically significant difference in the control group (P > 0.05). Therefore, data for both sides in the control group were pooled for further analyses. Statistical comparison of measurements for the normal and cleft sides in the study group is shown in Table 2. There was statistically insignificant difference in the study group (P > 0.05).

Statistical results of tests comparing the measurements of the control group and the normal side in the study group are shown in Table 2. There was statistically significant difference in the upper condylar height, condylar height, condylar width, and the ratio of the upper condylar height to the ramal height (P=0.000, P=0.000, P=0.000 and P=0.000, respectively). However, there was not statistically significant difference in ramal height and the ratio of the condylar height to the condylar width (P > 0.05). Statistical results of tests comparing the measurements of the control group and the cleft side in the study group are shown in Table 2. There was statistically significant difference in the upper condylar height, condylar height, condylar width, and the ratio of the upper condylar height to the ramal height (P=0.000, P=0.000, P=0.000 and P=0.003, respectively), but ramal height and the ratio of the condylar height to the condylar width did not exhibit any statistically significant difference (P > 0.05).

参考文献

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引言

Cleft lip and palate is one of the most common congenital craniofacial anomalies^[1-7]. Unilateral cleft lip and palate (UCLP) is the most common cleft type^[8-10], dentomaxillofacial deformities resulting from the clefts can lead to functional, esthetic, and psychosocial disturbances^[11-13]. Although operations can close the cleft in soft tissue, dentomaxillofacial deformities are not completely eliminated^[14-16], and it may be more and more seriously. The reconstruction of muscle caused by scarring and the malocclusion deformity with cleft lip and palate^[17-21], has influence on the function of the temporomandibular joint and the condylar morphology. Habets et al^[22] described a method for measuring the vertical condylar and ramal heights for comparing the right and left sides of the mandible for evaluating condylar and ramal asymmetry. This is an acceptable method for condylar asymmetry in unilateral posterior crossbite patients^[23], condylar asymmetry in bilateral posterior crossbite patients^[24]_, condylar and ramal vertical asymmetry in unilateral and bilateral posterior crossbite patients and a normal occlusion^[25], mandibular asymmetry in unilateral cleft lip and palate subjects^[26], unilateral posterior crossbite and unilateral cleft lip and palate on vertical mandibular asymmetry^[27], mandibular asymmetry in unilateral and bilateral posterior crossbite patients using cone-beam computed tomography[28], skeletal and dental asymmetries in Class II subdivision malocclusions using cone-beam computed tomography^[29], and prevalence of mandibular asymmetries in growing patients[30]. In a recent study, Kurt et al ^[31] evaluated mandibular asymmetry in cleft lip and palate patients, and found statistically insignificant differences between the normal and cleft sides in the measurements in the UCLP patients. Mevlut Cellkoglu et al ^[32] reported condylar and ramal vertical asymmetry in adolescent patients with cleft
lip and palate evaluated with cone-beam computed tomography. In a review of the orthodontic literature, no published study was found that condylar morphology in patients with UCLP. This study was designed to mainly investigate the condylar morphology in the group of unilateral cleft lip and palate patients with comparison with subjects with non-UCLP patients, introducing to make treatment planning for UCLP patients.

中国组织工程研究杂志出版内容重点：干细胞；骨髓干细胞；造血干细胞；脂肪干细胞；肿瘤干细胞；胚胎干细胞；脐带脐血干细胞；干细胞诱导；干细胞分化；组织工程

材料方法

Design
This is a synchronous non-randomized comparative study.

Time and setting
Experiments were performed at the Department of Orthodontics, the Affiliated Hospital of Qingdao University in China from December 2013 to November 2014.

Subjects
Study group: The patients were selected from the Department of Orthodontics, The Affiliated Hospital of Qingdao University in China.

Inclusion criteria: (1) Complete unilateral cleft lip and palate^[31]; (2) no systemic disease; (3) no history of orthodontic treatment; (4) had undergone surgery using the Tennison and Millard techniques for cleft lip construction and the Wardill-Kilner[33] pushback technique for surgical construction of the cleft palate.

Exclusion criteria: (1) History of past orthodontic treatment; (2) presence of unilateral and/or bilateral posterior cross-bite; (3) any known systemic disease affecting general growth and development.

The study group included 25 patients in the age range of 18 to 28 years (12 males and 13 females; mean age 21.20±3.10 years).

Control group included 25 subjects in the age range of 18 to 28 years (12 males and 13 females; mean age 21.16±2.56 years) with non-UCLP patients who met the following criteria: (1) class I skeletal and molar relationship; (2) all teeth present except third molars; (3) no significant facial asymmetry; exclusion criteria: (1) history of past orthodontic treatment; (2) presence of unilateral and/or bilateral posterior cross-bite; (3) any known systemic disease affecting general growth and development.

Methods
Measurement of condylar morphology
All panoramic radiographs were taken in a standard manner by the same operator, and were traced and measured manually by the same author. The outlines of the condyle and the ramal of both sides were traced on acetate paper. On the tracing paper^[22,32-34], a line (O₂O₃-line) was drawn between the most lateral points of the condylar (O₂) and of the ramal (O₃) image (Figure 1A), this distance from O₂ to O₃ was termed ramal height. To the O₂O₃-line (the ramal tangent) from the most superior point of the condylar (C0) image, a perpendicular C0O₁-line was drawn. The vertical distance from this line on the ramal tangent to O₂projected on the ramal tangent was measured; this distance was termed upper condylar height. A line (x-line) was drawn from the most lateral points of the neck of condylar (Figure 1B). To the x-line from the narrowest neck of condyle, a perpendicular y-line was drawn. The distance from C0 to y-line was measured and termed condylar height. The ratio of the upper condylar height to the ramal height and the ratio of the condylar height to the condylar width were calculated.

讨论

At present, panoramic radiographs with a relatively low radiation dose and a favorable cost-benefit relationship^[36-39], had become a routine tool for orthodontic diagnosis and treatment planning. There is magnification of the radiographic images of the structures in both the vertical and the horizontal directions, but according to Graber^[40], the magnification on panoramic radiographs is uniform and should not significantly affect diagnostic decisions. It was shown by some authors[^41] that vertical measurements, angle and symmetry measurements on panoramic radiographs are relatively reliable. In a recent study, Kambylafkas et al ^[36]stated that panoramic radiographs could be used to evaluate vertical posterior mandibular asymmetries. Many studies suggest that the reproducibility of vertical and angular measurements is acceptable if the patient’s head is positioned properly in the equipment^[42-45]. Habets et al ^[46]concluded that the head must be centered in the head holder when a panoramic radiograph is to be evaluated. All panoramic radiographs were taken in a standard manner by the same operator and the inadequate or poor-quality panoramic radiographs were excluded, with a simple method for evaluating horizontal distortion of the image is to compare the apparent width of the mandibular first molars bilaterally^[47]. Therefore, panoramic radiographs were chosen to be measured in this study.

Possible causative factors contributing to the development of mandibular asymmetry among subjects with UCLP include true skeletal asymmetry, asymmetrical mandibular fossa, and functional adaptation to dentoalveolar and occlusal disharmonies^[48]. Differential growth of the condyles can be caused by asymmetrical masticatory muscle activity position. Patients with UCLP generally present anterior and posterior crossbites and mid-face deficiency with a tendency towards a Class III malocclusion and abnormal muscular functions^[49]. In electromyographic studies, increased activity was reported in the anterior and posterior muscles on the crossbite side compared with the non-crossbite side[50]. This increased muscle activity might result in overloading of the condylar surfaces and therefore cause deformation or necrotic shrinkage of the condyles^[51-53]. Inui et al^[54]suggested that continuous condylar displacement in the glenoid fossa during the growth period derived from occlusal problems, induced differential growth of the condyles. Adaptations of the mandible to a new condition were seen generally in the condylar region because of active growth and development^[55].

Prolongation of abnormal muscular functions can cause changes in the growth center at the temporomandibular joint, because the condyle is one of the most sensitive areas to occlusal changes^[32]. Some studies have shown that functional displacement of the mandible over a long time either suppresses or activates mandibular growth, especially in the condylar region^[23]. The critical period is between age 7 and 10^[56]. In this study, we selected the patients with UCLP in the age range of 18 to 28. The growth potential of condyle has become more and more small and ever been over in this period.

In this study, there was statistically insignificant difference between the normal and cleft sides in the measurements in the UCLP group. Horswell and Levant^[57] who compared 16 UCLP subjects with published cephalometric standards did not find any significant differences in mandibular dimensions or morphology between the two groups. Kurt et al ^[31] evaluated mandibular asymmetry in cleft lip and palate patients, and reported statistically insignificant differences between the normal and cleft sides in the measurements in the UCLP patients. In this study, difference between the normal and cleft sides in the measurements in the UCLP group was not statistically significant. The reason may be condylar reconstruction. As the condylar reconstruction, upper condylar height, ramal height, condylar height and condylar width in two sides in the UCLP patients are similar.

There was statistically significant difference between the UCLP group and the non-UCLP sample in the upper condylar height, condylar height, condylar width, and the ratio of the upper condylar height to the ramal height (P < 0.01), other measurements did not show any significant differences (P > 0.05). The upper condylar height, condylar height, condylar width, and the ratio of the upper condylar height to the ramal height in the UCLP group were significantly lower than measurements of non-UCLP group. It may be deduced that scarring tissue, malocclusion deformity^[58], entomaxiliofacial deformity and abnormal muscular functions, have mainly influence on the condylar reconstruction and absorption, and less on the ramal growth.

The findings of this study may have some clinical implications. Orthodontic treatment planning should consider the condylar morphology in the UCLP patients[59]. Early correction of malocclusion deformity, dentomaxiliofacial deformity and abnormal muscular functions in UCLP patients can prevent condylar reconstruction and absorption.

The weaknesses of this study are the small-sample size and the limitations of panoramic radiographs. For further evaluation, it will be necessary to carry out studies with a larger sample and perhaps use CBCT for further evaluation^[60-62].
There was statistically insignificant difference between the normal and cleft sides in the measurements in the UCLP group.

The upper condylar height, condylar height, condylar width, and the ratio of the upper condylar height to the ramal height in the UCLP group were significantly lower than measurements of non-UCLP group.