Malignant hyperthermia in a patient receiving nitrous oxide

A patient who had malignant hyperthermia that apparently was triggered by nitrous oxide anesthesia even though he was premedicated with dantrolene sodium was successfully managed on a separate occasion using dantrolene without nitrous oxide.     

Evaluation of a subcutaneously implanted hydroxylapatite-avitene mixture in rabbits

Avitene, a microfibrillar collagen hemostatic agent was mixed with hydroxylapatite and implanted subcutaneously along the inferior border of the mandible in ten rabbits. This mixture clearly enhanced surgical manipulation of the implants. Radiographic and histologic examination of the implant sites at one, three, and six months showed an acceptable host response with no apparent alteration of the favorable characteristics of hydroxylapatite implants.     

Intramuscular hemangioma of the tongue

A case of intramuscular hemangioma of the tongue originally suspected to be an epidermoid or dermoid cyst was presented. The correct diagnosis was discovered during surgery, when uncontrollable bleeding and the results from a frozen section revealed the true nature of the lesion.     

Reconstructive prosthetic surgery of massive craniofacial injury

A case has been presented of reconstruction for a patient with massive injuries of the face and jaw. Reconstructive surgery, including bone grafting, skin grafting, and placement of the mandibular staple bone plate, and prosthetic rebuilding of eyes and dentures have made him a reasonably functioning and cosmetically acceptable individual.     

Fluctuating asymmetry of dynamic smiles in normal individuals

The aim of this study was to quantify the fluctuating dynamic facial asymmetry during smiling in a group of ‘normal’ adults, using three-dimensional (3D) motion facial capture technology. Fifty-four male and 54 female volunteers were recruited. Each subject was imaged using a passive markerless 3D motion capture system (DI4D). Eighteen landmarks were tracked through the 3D capture sequence. A facial asymmetry score was calculated based on either a clinically derived midline or Procrustes alignment; scores were based on the Euclidean distance between landmark pairs. Facial asymmetry scores were determined at three time points: rest, median, and maximum frame. Based on the clinically derived midline and on Procrustes alignment, the differences between male and female volunteers, as well as those at the three different time points, were not clinically significant. However, throughout a smile, facial and lip asymmetry scores increased over the duration of the smile. Fluctuating facial asymmetry exists within individuals, as well as between individuals. Procrustes superimposition and the clinically derived midline produced similar asymmetry scores and both are valid for symmetrical faces. However, with facial asymmetry, Procrustes superimposition may not be a valid measure, and the use of the clinically derived midline may be more appropriate, although this requires further investigation.     

A prospective study of complications related to mandibular third molar surgery

A prospective study that evaluated the surgical and postsurgical problems of 9,574 patients of a wide range of ages who had had 16,127 third molars removed was performed. It was concluded that removal of mandibular third molar teeth during the teenage years resulted in decreased operative and postoperative morbidity.     

Massive craniofacial injury: initial treatment and methods of reconstruction

A patient with a massive craniofacial injury is presented to illustrate useful flaps that may be used in the reconstruction of this type of injury. Initial management, consisting of basic life support, is indicated, because many patients who appear to be unsalvageable may be successfully restored to an active, productive life. Reconstruction of soft-tissue deficits was accomplished using the forehead and deltopectoral flaps. Although other methods of reconstruction may be used, the forehead and deltopectoral flaps remain among the more reliable flaps to restore thin lining to mucosal and external skin surfaces where bulky tissues are not desired.     

Augmentation of an atrophic edentulous mandible by interpositional grafting with hydroxylapatite

The clinical use of densely sintered calcium hydroxylapatite as a substitute for autogenous bone in interpositional grafting of an atrophic edentulous mandible is described. Results indicate this material appears to be a successful bone substitute for use in the rebuilding of the atrophic mandible.     

Light-transmitting fiber optic posts: An in vitro evaluation

Statement of problem

The clinical challenge of adhering cement to intracanal dentin is transmitting light to the most apical parts of root canals to allow more efficient polymerization of the cement.

Tracheal Stenosis after Tracheostomy

INTRODUCTIONTracheal stenosis is a late and usually non-life threatening complication of surgical and percutaneous tracheostomies (PDT) as well as delayed endotracheal extubation.METHODSWe undertook a retrospective review of all patients who underwent a surgical tracheostomy over a 10 year period. Patients were included in the study if they had CT or MRI imaging of the tracheostomy site both pre-operatively and six or more weeks post operatively. Patients whose imaging was not available were excluded (n = 3) as were those patients who still had a tracheostomy in situ (n = 8). In total 91 patients were included in the study. In the same period 1170 surgical tracheostomies were performed by the maxillofacial surgeons. The images were analysed by a radiologist and the degree of stenosis reported.RESULTSAll 91 patients underwent a tracheostomy with a window. 83 patients did not demonstrate any stenosis. Looking at the remaining 8 patients with stenosis: 6 patients had stenosis of less than 25%, 1 patient had stenosis between 25-50% and 1 patient had stenosis greater than 50%. Both patients with stenosis greater than 25% had more than one surgical tracheostomy.CONCULSIONWe have shown that the risk of stenosis is 8.8%, lower than often quoted in literature, and when it occurs it is likely to be symptomatic only in severe stenosis. Our main risk of stenosis was repeat surgical tracheostomies which also seems to be linked to a greater degree of stenosis.     

Biologic basis for interpositional autogenous bone grafts to the mandible

Interpositional autogenous bone grafting procedures were performed in the mandibles of 12 beagle dogs to assess cell survival within the graft and the superiorly repositioned alveolus, and to monitor the remodeling process. Histologic and radiologic results indicated that the grafts were well accepted and that new bone was rapidly laid down on their trabeculae. However, the osteocytes within the autografts generally did not survive. There was no evidence of necrosis of the superiorly displaced alveolus, nor any resorption of its surface cortex, and it rapidly united with the autograft and the mandible to produce a stable structure. This study confirms that the lingual pedicle of soft tissue is adequate to maintain the viability of the superiorly repositioned alveolus or segment and to allow rapid remodeling of the autogenous bone graft.     

羟基磷灰石─—胶原复合材料动物实验的钙磷元素定量分析和扫描电镜研究

本实验将羟基磷灰石—胶原复合材料和单纯羟基磷灰石植入10只成年狗颌骨缺损内，通过对钙、磷元素的定量分析和扫描电镜观察，研究胶原粘结剂的加入对羟基磷灰石生物特性的影响及该复合材料的成骨特性。结果表明，胶原粘结剂的加入不影响羟基磷灰石良好的成骨作用，且对新骨生长有一定的促进作用。复合材料固泣成型作用良好，与新骨形成完全的骨整合。     

口腔颌面外科的发展见证中国改革开放30年——2008年西雅图会议的启示

改革开放为中国的口腔颌面外科发展带来了无限生机,学术机构日益完善,学术队伍不断壮大,国际交流不断加强,但也面临着许多新的挑战.为了走出目前的困境,提出了一些有益的建设性意见和建议.     

Space conditions and prevalence of anterior spacing and crowding among nine-year-old schoolchildren

Abstract

Objective: To give detailed insight into the space conditions and prevalence of spacing and crowding in schoolchildren at nine years of age. The reliability and validity of screening methods was also assessed.

Design: Epidemiological survey.

Setting: South-western part of Germany (Rhein-Neckar-Kreis); elementary schools in a region with a low orthodontic care rate.

Sample and methods: 494 nine-year-old German schoolchildren (237 males, 257 females, median age 9 years) were examined orthodontically in cooperation with the local community dentistry service. A special measurement ruler was developed to enhance validity and reliability of space measurements on location in the schools.

Results and conclusions: Concerning space conditions in the incisor segments: in the maxilla the variety encountered comprised both space excess and moderate to severe crowding. This was considerably larger in the maxilla than in the mandible. Severe crowding (>5 mm) was found more often in the maxilla than in the mandible and affected around 2–3% of the maxillary dentitions. Also severe contact point displacements (IOTN Grade 4) were mainly restricted to the maxilla (prevalence approximately 3%).

In the canine–premolar segments, the arch segments in males were in general around 0.5 mm larger than among the females, also within each dental stage. In general, the maxilla was more often affected by posterior crowding than the mandible. Anterior crowding seemed to be more prevalent than posterior crowding. With respect to the screening methods used in the present study, reliable and valid measurements were also found to be possible in schools. This may open up further opportunities for orthodontic screening by community dentistry services or similar organizations.