无牙颌患者不同垂直距离时下颌位置的研究

目的　探讨无牙颌患者不同垂直距离时下颌骨及髁状突的位置变化。方法　对无牙颌患者制作不同高度 (H-2 、H-6、H-10 )全口义齿 ,在头颅定位下分别拍摄头颅侧位X线片 ,比较分析SND、GoGn -SN、ANB、SL、SE测量值与垂直距离间的关系。结果　从H-2 到H-10 位SND、SL值呈逐渐增大 ,GoGn -SN、ANB值呈逐渐减小趋势。SE值从H-2 到H-6位时亦呈增大趋势 ,而在H-10 位时SE值明显减小。结论　随垂直距离减小 ,下颌骨颏部向前上、髁状突向后发生旋转移位。当垂直距离减小到一定程度时 ,下颌骨可能发生整体前移 ,而并非是髁状突继续向后移位。     

无牙颌患者垂直距离对髁状突前斜面应力分布的影响

目的探讨无牙颌患者垂直距离对髁状突前斜面应力分布的影响。方法构建无牙颌患者配戴不同垂直高度全口义齿时下颌骨及颞下颌关节三维有限元模型,分析载荷状态下髁状突前斜面的应力分布状况。结果髁状突前斜面下外侧为主要应力集中区,随垂直距离变化:由H-2位到H-4、H-6位时各区应力值呈减小趋势,在H-8位时各区应力值又呈增大趋势。结论无牙颌患者垂直距离变化对髁状突前斜面应力分布产生影响。     

不同体位下无鼾者与OSAHS患者的头影测量比较

目的:借助X线头影测量分析,探讨3种不同体位下,无鼾者和阻塞性睡眠呼吸暂停低通气综合征(Obstructivesleepapneahypopneasyndrome,OSAHS)患者的颅面结构及气道周围软硬组织的关系。方法:10例无鼾者和10例OSAHS患者在3种不同体位下,分别拍摄常规坐位头影测量侧位片及仰卧位、放松位头颅侧位片,并进行头颅测量分析。结果:同一体位下,与无鼾者相比,OSAHS患者的ANB角、软腭厚度及舌骨前上点至下颌平面垂直距离增加,口咽距(U-Pu)减小;仰卧位和放松位时,无鼾者的SNB角、MP-SN角均比坐位时减小,SPT增加;H-C3距、PAS距减小;OSAHS患者H-C3距比坐位时也减小。结论:3种不同体位下,无鼾者与OSAHS患者在颅面结构及气道周围软硬组织结构关系方面的差异具有显著性。     

咬合垂直距离减低的无牙颌患者治疗前后面部形态及TMD的变化

目的：探讨咬合垂直距离改变对无牙颌TMD患者治疗前后面部形态影响。方法：对无牙颌TMD垂直距离减低的48例患者恢复垂直距离前后,拍头颅侧位X线片并进行测量。结果：咬合垂直距离改变对无牙颌TMD患者治疗前后面部形态主要发生在面下1/3, YA角, MPA角N-Me距离均增加,并有显著性差异,说明恢复垂直距离后,下颌颏部向下向后顺时针移位, TMD症状缓解。结论：恢复无牙颌咬合垂直距离后,下颌颏部向下向后顺时针移位, TMD症状缓解,面部形态相应改变。     

安氏Ⅰ类错与安氏Ⅱ~1错患者颅面关系的研究

目的 :探讨安氏Ⅰ类错牙合与安氏Ⅱ1错牙合患者颅面结构的差异。方法 :随机选取 11～ 14岁的年轻恒牙列病例 45例 ,其中安氏Ⅰ类错牙合2 4例 ,安氏Ⅱ1错牙合 2 1例 ,在正中咬合位时拍摄X线头颅定位侧位片 ,比较两者颅面结构的差异。结果 :安氏Ⅱ1错牙合患者SNB、ANB、SNPg、FMA的测量值大于安氏Ⅰ类错牙合患者 (P <0 .0 5 ) ,而SNA、PP SN、OP SN、GoGn SN的测量值两者间无显著差异。结论 :安氏Ⅰ类错牙合与安氏Ⅱ1类错牙合X线头影测量的主要差异是下颌位置的异常。     

全口义齿垂直距离修复前后颌面形态的对比研究

通过对22例戴全口义齿2～5年患者常规修复新总义齿,升高咬合垂直距离,面部测量、头部X线片及(牙合)磨耗测量,发现面部形态的改变主要发生在下颌:面下1/3距离更接近面中1/3;(牙合)间隙减小;下颌颏点向下、向后移位;下颌体呈现顺时针旋转移位;上颌骨移位不明显,说明咬合垂直距离影响面部形态。(牙合)垂直距离恢复升高对无牙颌面部变化的长期影响尚待进一步研究。     

广东正常人颅颌面形态的三维分析

作者采用X线头影测量一电子计算机系统对100名正常(牙合)广东汉族人的头颅定位正、侧位片进行三维分析。结果表明:颅颌面横向、垂直向的生长发育男性大于女性,而颏部的生长发育女性大于男性;面下部的垂直高度在13岁以后还继续增长;而上颌骨宽度在第一恒磨牙萌出后基本稳定;广东人眼眶的横向距及颅颌面矢状线矩比西安人大,而颅颌面垂直距离及上颌骨宽度、上下牙弓宽度比西安人小。     

PancherzⅡ类错矫正分析方法评价Activator的治疗机制

目的 :探讨 Activator对生长发育期 类 1分类患者的牙和颌骨的作用机制。方法 :应用 Pancherz 类错牙合矫正分析法 (Class correction analysis)结合传统测量项目对 2 2例 (男 8例 ,女 14例 ,年龄男 10～ 13岁 ,女 9～ 12岁 ) ANB角大于 5°、前牙覆盖大于 7mm、磨牙完全远中或尖对尖远中关系患者的治疗前后 X线头影测量分析项目进行配对 t检验。结果 :SNA减小 ,Go- Me增大 ,NSL / ML增大 ,ANB角减小 ,前后面高增加 ,下颌位置 Pg/ OL P前移均有显著性差异。上中切牙角变小 ,下切牙角度变大 ,下磨牙前移 ,磨牙关系得到改善。结论 :Activator对下颌骨的矫形作用比较复杂 ,下颌骨的绝对长度增加 ,下颌平面角加大 ,SNB角无变化 ;Activator可以改善前牙的覆盖 ,后牙的 类关系及 类骨关系。     

下颌前移矫正器治疗阻塞性睡眠呼吸暂停综合征患者的疗效分析

目的　分析下颌前移矫正器治疗阻塞性睡眠呼吸暂停综合征 (OSAS)的临床疗效及与颅面结构、上气道的关系。方法　对 4 0例轻、中度OSAS患者进行治疗前X线头影测量 ,睡眠时戴用下颌前移矫正器治疗 ,用多导睡眠图监测评价疗效 ,并与颅面结构、上气道各指标进行相关分析。结果　下颌前移矫正器治疗OSAS患者的客观有效率为 88.6 %。治疗前、后睡眠呼吸暂停的通气指数 (AHI)减少百分比 (△AHI)与颅面结构中的SNB角 (r =- 0 4 97) ,ANB角 (r=0 .5 36 )及下颌平面角MP -FH(r=- 0 2 5 2 )相关 ,亦与舌骨高度H -MP(r=- 0 35 1)及软腭的长度SPL(r=- 0 36 6 )相关。结论　下颌前移矫正器通过前移下颌间接扩大上气道达到治疗效果     

无牙颌患者自然头位的研究

目的：了解无牙颌患者相对于有牙个体自然头位（natural head posture,NHP)的差异，以及义齿戴入即刻和戴用后短期NHP的变化。方法；分别选取20例无牙颌患者和22名有牙对照组个体，采用视线标记的头颅定位侧位片记录NHP。无牙颌患者拍摄义齿戴前、义齿戴入即刻和戴用3个月后3张X线片。有对照组拍摄一张X线片。选取6项角度测量值评价NHP，3项角度测量值和2项线距测量值评价下颌骨的位置。比较无牙颌患者义齿戴前与牙对照组上述指标的差异，以及义齿戴入即刻和戴用3个月后的变化。下颌骨垂向明显上移（P＜0．05）。义齿戴入即刻，颈椎曲度显著增高（P＜0．05）。义齿戴用3个月后，颅颈角显著减小（P＜0．05）。结论：无牙颌患者在义齿戴入即刻和戴入后短期，自然头位出现一定程度的改变；与不戴义齿的头位相比较，调整至一个新的更接近正常的平衡状态。     

无牙颌患者颞下颌关节凹形态的研究

目的探讨无牙颌患者垂直距离变化与颞下颌关节凹形态改建的关系。方法对两组不同垂直高度的无牙颌患者摄下颌姿势位双侧颞下颌关节标准薛氏位片,测量关节凹中心O’点与底边中点O之间的水平距离,并进行组间比较。结果关节凹中心与O点之间的水平距离在对照组平均为(-1.07±0.46)mm,在实验组平均为(0.55±0.42)mm。结论牙列长期缺失或总义齿人工牙重度磨耗致垂直距离明显降低时,其颞下颌关节凹有向前改建的趋势。     

Peri-implant mucosal level in patients treated with implant-supported fixed prostheses: a 1-year follow-up study

PURPOSE: The purpose of this follow-up study was to quantify the change in the peri-implant mucosal level after treatment of edentulous patients with fixed prostheses on osseointegrated endosseous implants. MATERIALS AND METHODS: Twenty patients were included in the study: 10 were treated in the maxilla, and 10 were treated in the mandible. Both groups had fixed prostheses on osseointegrated Br?nemark implants. Peri-implant mucosal level was measured with a calibrated probe after removal of the prostheses at the 1-year follow-up. These measurements were compared to those made on the original master casts. RESULTS: A larger mean retraction (-) was observed in the mandible (-1.6 mm) compared to the maxilla (-0.8 mm), but there was great variation. The individual values varied from -4.5 to +1.0 mm in the mandible and from -6.0 to +6.0 mm in the maxilla. CONCLUSION: Peri-implant soft tissue recession occurs during the first year in edentulous jaws after treatment with implant-supported fixed prostheses and more so in the maxilla than the mandible.     

The vertical heights of maxillary and mandibular bones in panoramic radiographs of dentate and edentulous subjects.

OBJECTIVE: The purposes of this study were to determine the variation in maxillary and mandibular vertical measurements made from panoramic radiographs and to assess differences in measurements between dentate and edentulous jaws. METHOD AND MATERIALS: A total of 192 alveolar ridges (96 dentate and 96 edentulous) were examined. The mean ages of the dentate and edentulous groups were 51.05 and 59.98 years, respectively. Measurements were made from reference lines drawn from anatomic landmarks on standardized panoramic radiographs. RESULTS: In the dentate group, there was no statistically significant difference between men and women in the height of the maxilla. However, the height of the mandible was significantly greater in men than in women. In the edentulous group, the heights of the maxilla at the anterior and first premolar regions were significantly greater in men than in women. In the same group, mandibular heights were also significantly greater in men than in women. Reductions in the height of the edentulous mandible and maxilla were significantly more pronounced in women than in men. The decrease in the vertical height of the maxilla was not statistically significant in men. CONCLUSION: There are differences between the sexes in alveolar ridge resorption after tooth loss.     

Research methods in dentistry 9. Follow-up of permucosal implants in an edentate mandible using panoramic radiography

Panoramic radiographs are frequently used for routine follow-up of mandibular implants. The objective of this study was to determine whether measurement on a panoramic radiograph of the vertical dimension of the mandible near by an implant, using the known implant length as a reference, is a reliable method. In 11 patients, 2 permucosal implants were placed in the anterior part of the edentulous mandible. During the first year after implantation, 2 panoramic radiographs and 2 sets of standardized oblique lateral cephalometric radiographs were made. Oblique lateral cephalometric radiographs are the golden standard for measuring the vertical dimension of an edentulous mandible. The length of the implants and the vertical dimension of the mandible dorsally to the implants were measured on all oblique lateral cephalometric radiographs. The measured and known implant length were used to calculate the image enlargement factor. This factor was used to calculate the real vertical dimension of the mandible. The same measurement procedures were performed on the panoramic radiographs. Using a paired t-test, the calculated values of the vertical dimensions of the mandibles found on panoramic radiographs were compared with the calculated values found on oblique lateral cephalometric radiographs. No statistically significant differences were found. It was concluded that under the described circumstances, panoramic radiographs can be used for reliable measurement of the vertical dimension of the mandible near by permucosal implants.     

Vertical distraction of the severely resorbed edentulous mandible: an assessment of treatment outcome

PURPOSE: To assess the treatment outcome (implant survival, surgical complications, patient satisfaction) of vertical distraction of the severely resorbed edentulous mandible. MATERIALS AND METHODS: Forty-six patients with severe resorption of the edentulous mandible (bone height 5 to 8 mm, median 6 mm) participated in this study. The anterior segment of the mandible was vertically augmented using the Groningen distraction device. One or 2 months after the last day of distraction, 2 implants (n = 92) were placed. Standardized clinical and radiographic assessments were performed annually, and patient satisfaction was scored on a 10-point rating scale (0 = completely dissatisfied; 10 = completely satisfied). RESULTS: Three implants were lost during the healing phase, but none were lost for the rest of the follow-up period (72 +/- 10.3 months), resulting in an implant survival rate of 97%. One patient developed a fracture of the mandible 3 days after the last day of distraction; it healed uneventfully. The mean mandibular bone resorption during follow-up as measured on radiographs in the midline and distal of the implants was 9.8% +/- 0.6% and 10.2% +/- 0.8%, respectively. In 4 patients radiolucency in the distracted area persisted during the follow-up period. Four patients reported a slight sensory disturbance at the final evaluation visit. All patients functioned well with their prostheses. The mean patient satisfaction score after treatment was 8.1 +/- 1.2. CONCLUSION: Vertical distraction of the anterior segment of a severely resorbed alveolar ridge of the mandible can provide a proper basis for insertion and osseointegration of endosseous load-bearing implants with good implant survival, few surgical complications, and good patient satisfaction.     

Cross-sectional analysis of the mandibular lingual concavity using cone beam computed tomography

Objectives: To study the prevalence and the degree of lingual concavity in the edentulous first molar region from cone beam computed tomography (CBCT) scans of the mandibles. Material and methods: Qualified cross‐sectional images in mandibular first molar edentulous region taken from CBCT were selected. The mandible morphology 2 mm above the inferior alveolar canal (IAC) was classified into the convex (C), parallel (P) and undercut (U) type, based on the presence of lingual concavity and the shape of alveolar ridge. The prevalence of each group was determined. Subsequently, the lingual concavity characters, including the depth, the angulation and the vertical location were determined by the measurements of selected anatomic landmarks. Results: One hundred and three subjects (mean age 51 with a range of 23.7–70.4 years) were studied. The U type was the most prevalent, accounting for 66% of the study population. The mean undercut depth and angulation at the level 2 mm above IAC were on average 2.4 mm and 57.7°. The mean vertical distances from the most prominent point (P) of the lingual concavity to the cemento‐enamel junction of second premolar and the inferior border of the mandible were 11.7 and 14.9 mm, respectively. Conclusions: The anatomic location and the degree of the lingual concavity presented in this article add more information in implant treatment planning in the mandibular first molar edentulous region. To cite this article:
Chan H‐L, Brooks SL, Fu J‐H, Yeh C‐Y, Rudek I, Wang H‐L. Cross‐sectional analysis of the mandibular lingual concavity using cone beam computed tomography.
Clin. Oral Impl. Res. 22 , 2011; 201–206.
doi: 10.1111/j.1600‐0501.2010.02018.x     

三维转化头影测量法评估咬合垂直距离的研究

目的 对三维转化头影测量法、发音法及息止间隙法确定的云南省汉族无牙颌患者咬合垂直距离的准确性进行比较和分析。方法 首先建立云南省汉族正常者锥形束CT（CBCT）头颅侧位影像各标志点间相关性数据库,随后选取5名63~78岁云南省汉族无牙颌患者,使用NNT.View软件对由CBCT转化的头颅侧位片的各硬组织标志点进行测量分析,结合正常人群数据库,评估出咬合垂直距离,并对CBCT转化头影测量法、发音法及息止间隙法确定的咬合垂直距离进行分析。结果 本研究以发音法为标准参照组,分析了息止间隙法和6种CBCT转化头影测量法（包括N-ANS/ANS-Me、S-Go/N-Me、ANS-Gn/N-ANS、ANS-FH/Me-FH、ANS-Xi-Pm、CA/LA）与发音法的差值,结果发现：7种测量方法与发音法均有很高的一致性（组内相关系数>0.986）;其中息止间隙法、N-ANS/ANS-Me、S-Go/N-Me法差值的绝对值较其他4组更小,而ANS-FH/Me-FH差值的绝对值最大,差异均有统计学意义（P<0.05）。结论 三维转化头影测量法除ANS-FH/Me-FH外,其余5种方法均可为临床评估无牙颌患者咬合垂直距离提供参考。     

General and local contraindications for endosseal implants - an epidemiological panoramic radiograph study in 65-year-old subjects

Abstract In order to evaluate general and local contraindications for implantation for 65-yr-old subjects from a medium-sized Finnish city, 431 such persons were examined anamnestically and by means of panoramic radiographs. The population represents 61% of the total age group in the city (born in 1923). It was shown that several degrees of cardiac problems and increased blood pressure followed by pulmonary diseases and diabetes were the most commonly encountered relative contraindications for implantation. Eleven percent of the patients said that they smoked regularly and the bone quality was estimated to be less suitable for implantation in 21% of the cases. Implantation was evaluated according to the Bonefit® system (implant lengths between 6 and 16 mm) in 10 regions in the maxilla and 6 regions in the mandible and was shown to be possible in 38% of the regions in the partially edentulous maxillae and 50% of those in the partially edentulous mandibles, the corresponding figures for the edentulous jaws were 55% in the maxilla and 61% in the mandible.