Topography and Spatial Fascicular Arrangement of the Human Inferior Alveolar Nerve

Background: Topography and fascicular arrangement of the inferior alveolar nerve (IAN) can provide critical information for the estimation of damage to IAN based on patient symptoms, or conversely to evaluate the symptoms resulting from injury to the IAN. Purpose: The fascicular composition and organization of the IAN were determined to confirm the microarchitecture of the IAN bundles into each of the mandibular teeth, including the composition of the mental nerve. Materials and Methods: The IAN within the mandibular canal (MC) was examined in 30 hemifaces of embalmed Korean cadavers. Results: The most common patterns of nerve fascicle innervation to the mandibular teeth could be grossly classified into three: (1) the superior buccal portion of the IAN innervating the molars, (2) the superior portion innervating the premolars, and (3) the superior lingual or the superior lingual and inferior lingual portions in the posterior MC and the lingual portions in the anterior MC, innervating the incisors and canine. The buccal two‐thirds portion of the IAN was composed of the mental nerve. Conclusion: The IAN had distinctive fascicular organizations, which make it possible to forecast the degree, location, and extent of nerve damage according to presenting symptoms.     

The Dynamax System: A new orthopaedic appliance and case report

Abstract

The Dynamax appliance is a treatment modality for the correction of the Skeletal II malocclusion characterized by a mandibular retrusion. Progressive mandibular advancement, maxillary expansion, control of maxillary growth, incisor torque and control of vertical facial development are incorporated into a two-part appliance. The design facilitates laboratory construction, clinical handling and patient acceptability.

A prefabricated spring module forms the basis of the appliance, allowing both maxillary expansion and mandibular advancement. An easily adjustable progressive forward position of the lower jaw makes a construction bite unnecessary.

The spring module provides most of the structure of the appliance so that minimal acrylic is required and the appliance is fully contained within the freeway space. Contact between the upper and lower parts of the appliance occurs posteriorly in the lingual sulcus. Here the depth permits an extended vertical contact, to maintain a protrusive mandibular position throughout the range of mandibular opening, including during sleep. The lower portion of the appliance may be fixed or removable and multibracket treatment can be carried out in one or both arches at the same time as the orthopaedics.     

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目的探讨下颌骨骨折不同手术时机与术后并发症的关系。方法回顾2007--2012年济南市第五人民医院口腔科收治的下颌骨骨折患者61例,按伤后手术时机的不同将患者依次分类,观察各患者术后感染、骨折畸形愈合和骨折不愈合的发生情况,数据采用Logistical回归分析和方差分析。结果61例患者中有5例出现术后并发症,无骨折不愈合病例。Logistical回归分析得知延迟手术对全部并发症的相对危险度为0．61（P=0．12）,对感染的相对危险度为0．82（P=0．39）,对骨折畸形愈合的相对危险度为0．61（P=0．12）;各组并发症发生与否的手术时机差异无统计学意义（P〉0．05）。结论下颌骨骨折的手术时机与术后并发症的发生无明显关联。     

两种方法在拔除下颌阻生第三磨牙中的疗效比较

目的:观察和比较两种拔除下颌阻生第三磨牙的临床疗效。方法:门诊200例下颌阻生第三磨牙随机分为两组,各100颗。分别采用传统锤凿去骨法和涡轮机去骨法拔除,记录手术时间、术后疼痛、张口受限等情况并进行统计学分析。结果:两种手术方法在手术时间、术后疼痛、张口受限、肿胀程度等方面有统计学差异(P<0.05),传统锤凿去骨组出现干槽症与下唇麻木分别为5例和1例,涡轮机去骨组分别为1例和0例,组间比较差异无统计学意义(P>0.05)。结论:与传统锤凿去骨法相比,采用涡轮机去骨法拔除下颌阻生第三磨牙手术时间短,术后并发症较少,值得临床推广。     

Static reconstruction of malar region in facial paralysis: A new alternative technique for plasty of symmetric mouth appearance

Abstract

Static suspension using fascia lata graft is used as a reconstructive procedure against drooping of the mouth corner for treating longstanding facial paralysis. Although it achieves symmetry at rest, movement of the mouth corner at mouth opening is restricted to some extent because it is fixed with fascia lata to the immovable temporal fascia, the parotid fascia, or bones. This was overcome by suspending the mouth corner to the mandibular coronoid process with fascia lata, which enabled a shift of the mouth corner with mouth opening and closure. The nine patients discussed in this study were operated on since 1994 for longstanding facial paralysis and followed-up for over 1.5 years. As in conventional static suspension, the fascia lata was harvested and split into two bands. Next, one semi-oval fascial loop was inserted around the paralysed part of the mouth and tied with another fascial band at the mouth corner, which was looped to the mandibular coronoid process. The suspended fascia lata graft was relaxed with anteroinferior movement of the coronoid process at mouth opening, enabling the mouth corner to shift inferiorly. The mouth corner returned to its original position at mouth closure, and the nasolabial fold deepened during mastication. No limitation in mouth opening was observed. Suspension of the mouth corner to the mandibular coronoid process provided a dynamic element, thereby restoring a near-normal shift. The procedure is considered as an alternative for reconstructing the malar region of patients with facial paralysis and in whom dynamic reconstruction is not indicated.     

Hepatocyte growth factor stimulates root growth during the development of mouse molar teeth

Sakuraba H, Fujiwara N, Sasaki‐Oikawa A, Sakano M, Tabata Y, Otsu K, Ishizeki K, Harada H. Hepatocyte growth factor stimulates root growth during the development of mouse molar teeth. J Periodont Res 2012; 47: 81–88. © 2011 John Wiley & Sons A/S Background and Objective: It is well known that tooth root formation is initiated by the development of Hertwig’s epithelial root sheath (HERS). However, relatively little is known about the regulatory mechanisms involved in root development. As hepatocyte growth factor (HGF) is one of the mediators of epithelial–mesenchymal interactions in rodent tooth, the objective of this study was to examine the effects of HGF on the root development of mouse molars. Material and Methods: The HERS of mouse molars and HERS01a, a cell line originated from HERS, were used in this study. For detection of HGF receptors in vivo and in vitro, we used immunochemical procedures. Root development was assessed by implanting molar tooth germs along with HGF‐soaked beads into kidney capsules, by counting cell numbers in HERS01a cell cultures and by performing a 5′‐bromo‐2′‐deoxyuridine (BrdU) assay in an organ‐culture system. Results: HGF receptors were expressed in the enamel epithelium of molar germs as well as in HERS cells. HGF stimulated root development in the transplanted tooth germs, the proliferation of HERS01a cells in culture and HERS elongation in the organ‐culture system. Examination using BrdU revealed that cell proliferation in HERS was increased by treatment with HGF, especially that in the outer layer of HERS. This effect was down‐regulated when antibody against HGF receptor was present in the culture medium. Conclusion: Our results raise the possibility that HGF signaling controls root formation via the development of HERS. This study is the first to show that HGF is one of the stimulators of root development.