Analisi della morfologia radicolare e canalare di molari superiori ed inferiori in una popolazione Caucasica: studio in vivo alla CBCT

AimTo investigate the root and canal morphology of maxillary and mandibular permanent molar teeth in a Caucasian population by using Cone Beam Computed Tomography (CBCT).MethodsA total of 596 permanent molars were included. The number of roots, the number of canals per root and the root canal configurations according to the method of Vertucci were recorded.ResultsAlmost all of maxillary first molars (95.7%) had three separate roots; however, 40.3% of mesiobuccal roots had two canals (MB2). Of 157 maxillary second molars, 88.5% had three roots. Among the mesiobuccal roots, 15.1% had two canals. The majority of mandibular molars (100% of first molars, 89.4% of second molars) had two separate roots. Most distal roots had a simple type I configuration, whereas mesial roots had more complex canal systems, with more than one canal.ConclusionsCBCT is an efficient method of studying root canal systems.     

游离腓骨瓣楔形截骨术在下颌骨重建中的应用

目的:探讨游离腓骨瓣同期修复下颌骨缺损过程中应用楔形截骨塑形与小型钛板分段固定的方法.方法:16例下颌骨病变患者均按改良方法制备腓骨瓣,断蒂前在所需修复下颌骨的角部及颏部的相应位置上,直接由腓骨外侧面楔形截骨塑形,精细磨削截骨面,调整至所需的弧度及角度,采用2块小型钛板在腓骨的不同骨面固定.结果:16例患者的骨瓣及骨皮瓣均存活,出院时下颌骨颏部及下颌角外形良好,咬合关系、语音功能恢复正常或基本正常.术后15例随访3～18个月,下颌骨全景片示移植骨段均一期愈合.结论:应用楔形截骨法塑形结合小型钛板分段固定重建下颌骨,可灵活调整骨瓣所需的弧度和角度,使每个骨段得到充足的血供,有利于截骨段的愈合,安全可靠,制备简便,易于操作和掌握.     

An Investigation into the Changes in Airway Dimension and the Efficacy of Mandibular Advancement Appliances in Subjects with Obstructive Sleep Apnoea

Abstract

This prospective clinical study evaluates a group of 37 male Caucasians with obstructive sleep apnoea for changes in airway dimension and the efficacy associated with the use of mandibular advancement splints. Lateral skull radiographs were obtained with the subjects—upright in occlusion, supine in occlusion, and supine in protrusion. Each radiograph was traced and digitized, and changes in mandibular position, airway dimensions, and hyoid were examined. Subjects were invited to complete pre- and post-treatment questionnaires, and interviewed following fitting of a removable Herbst mandibular advancement splint.

Significant changes were recorded in the airway dimensions in response to both a change in position, from upright to supine, and in response to mandibular advancement. A compliance rate of 76 per cent was achieved with no reported serious complications associated with the use of mandibular advancement devices.     

锥形束计算机体层摄影术观察下牙槽神经管形态及其临床意义

目的 应用锥形束计算机体层摄影术（CBCT）观测并分析下牙槽神经管在下颌骨内的走行特点,探讨其分布规律,为临床手术提供解剖学依据.方法 采用单纯随机抽样法选取具备下颌后部CBCT 扫描数据的患者60 例,应用CBCT 自带的KaVo eXam Vision 软件测量颏孔区、前磨牙区、磨牙区下牙槽神经管与牙槽嵴顶、下颌骨颊舌侧骨板及下缘的平均距离,对各组测量项目进行成组t 检验比较,并观察其走行特点.结果 下牙槽神经管距下颌下缘小于距牙槽嵴顶的距离,在第二磨牙区距离下颌骨下缘最近;颏孔区至第一磨牙区间,下牙槽神经管距颊侧骨板距离小于距舌侧骨板距离,自第二磨牙后,下牙槽神经管距颊侧骨板距离则大于距舌侧骨板距离;性别及左、右侧下牙槽神经管距离差异无统计学意义（t＝2.437,P ＞ 0.05）.结论 CBCT 扫描有利于更好了解下牙槽神经管的走行及结构特异性,对牙槽外科及种植外科手术方案的制定具有一定临床指导意义.     

下颌角截骨术后咀嚼效率的评估

目的评估下颌角截骨术对患者咀嚼效率的影响。方法选择15例拟行下颌角截骨术（下颌角下颌缘切除合并下颌体部外侧骨皮质劈除术）患者,排除牙周疾病、颞下颌关节疼痛及偏颌等疾病,采用杏仁、小枣过筛称重法,分别测量患者术前、术后1个月及术后6个月的咀嚼效率。结果患者术后1个月与术前相比咀嚼效率明显减小,差异有统计学意义;术后6个月与术后1个月相比,咀嚼效率明显增大,差异有统计学意义;术后6个月与术前相比,差异无统计学意义。结论下颌角截骨术对患者的咀嚼效率无明显影响。     

Revascularisation of costochondral grafts: an experimental study in domestic pigs

Mandibular condyles are reconstructed immediately with costochondral grafts (CCGs) in children for several temporomandibular conditions, including ankylosis, benign neoplasia, and chronic arthritis. A prerequisite for growth of CCGs is that they are properly revascularised, but the revascularisation process has not to our knowledge so far been examined. The aim of the present study was therefore to investigate the revascularisation of CCGs when they were used for immediate reconstruction of the mandibular condyle in juvenile domestic pigs. Eleven mandibular condyles were experimentally resected and immediately reconstructed with CCGs. Microangiograms with an Indian ink solution were done 2, 4, 8, and 12 weeks after the reconstructions. The density of vessels was higher in measurement zones facing soft tissues than in those facing mandibular bone at all time points. Revascularisation of the growth plate originated from the surrounding recipient soft tissues and not from an endosteal blood supply from the host mandible ramus.     

Introduction of the "Rotterdam mandibular distractor" and a biomechanical skull analysis of mandibular midline distraction

The Rotterdam mandibular distractor (RMD) is a slim, rigid, boneborne distractor for use in midline distraction of the mandible. We did a biomechanical study to compare the RMD with the Trans Mandibular Distractor-flex (TMD-flex). This included an anatomical biomechanical study that was conducted on 9 dentate human cadaveric heads using both the RMD and the TMD-flex. In the vertical plane less tipping was measured in the RMD group than in the TMD-flex group. Significantly less skeletal tipping was found in the horizontal plane in the RMD group (P=0.021). There was minimal difference in the intercondylar distance between the groups. As the amount of lateral displacement of the condyle was similar in both groups and there was less rotational movement in the RMD group, the TMD-flex would be expected to increase stress on the temporomandibular joint. As a result of the increased parallel widening in the vertical plane, more basal bone is being created and less relapse is expected using the RMD. The study design involves an in vitro anatomical model and conclusions must be drawn with care. At present clinical studies are under way and results will follow.     

Validity and reliability of the Portuguese version of Mandibular Function Impairment Questionnaire

The aim of this study is to evaluate the validity and reliability of the Mandibular Function Impairment Questionnaire (MFIQ) (Portuguese version). Face and content validity of the Portuguese version were performed. To assess reproducibility of the data gathered with MFIQ, it was applied to 62 individuals who completed the questionnaire on two occasions. Validity and reliability of the data gathered with MFIQ were evaluated in a sample of 249 patients. Construct-related validity was assessed through factorial validity (by means of a confirmatory factor analysis), and convergent and discriminant validities were assessed, respectively, by the average variance extracted (AVE), composite reliability (CC) and bivariate correlations between factors. The internal consistency was estimated by the standardised Cronbach's alpha coefficient (α) and reproducibility by the intra-class correlation coefficient (ICC). All the items of MFIQ showed content validity. Reproducibility was excellent in both the 'functional capacity' dimension (D1) (ICC(D1) =0·895, 95% CI=0·832 to 0·935) and the 'feeding' dimension (D2) (ICC(D2) =0·825, 95% CI= 0·726 to 0·891). Items 1, 2, 6 and 7 of D1 had factor weights below the desired cut-off (0·5), and overall fit of the original bifactorial structure of the MFIQ was poor [(confirmatory fit index) CFI= 0·850, (goodness of fit index) GFI= 0·781, (root mean square error of approximation) RMSEA= 0·118]. Thus, these items were excluded, and the new, reduced version of the MFIQ showed good fit (CFI=0·933, GFI=0·879, RMSEA=0·099). The convergent validity was adequate (AVE≥0·5, CC≥0·7) for both factors. However, their discriminant validity was low (AVE(D1) = 0·51 and AVE(D2) = 0·66 <ρ(2) (D1D2) =0·70). The internal consistency was excellent (α(D1) =0·874; α(D2) =0·918). The Portuguese version of the reduced MFIQ produced data with good validity and reliability.     

利用曲面断层片进行下颌骨测量的研究

目的 评价利用曲面断层片进行下颌骨测量的可行性.方法 分别测量51 例患者的曲面断层片和头颅侧位片上的下颌角、下颌升支长、下颌体长、下颌综合长几项指标,分析其相关性.结果 下颌角、下颌升支长、下颌体长度、下颌综合长的测量值在曲面断层片上与头颅侧位片上的相应指标呈显著相关.结论 在统一拍摄条件下,曲面断层片能够用做下颌骨的测量.