Computerized infrared thermographic imaging and pulpal blood flow: Part 2. Rewarming of healthy human teeth following a controlled cold stimulus

AIM: To investigate the rewarming pattern and rewarming rate of clinically healthy teeth following a controlled cold stimulus using TI techniques. METHODOLOGY: A controlled cold stimulus was developed using an air stream at 20 degrees C. Gingival and incisal sites on 12 healthy maxillary lateral incisors in six patients were imaged under rubber dam following 20 s cooling. Images were captured at 10 s intervals during a 3-min rewarming period and the data used to construct graphs of the rewarming rate. Log transformation of the data was used to produce 'best fit' straight line graphs. Linear regression analysis was used to examine three variables, viz. the side of the mouth (right or left), the site of measurement (gingival or incisal) and the phase of rewarming (early 0-90 s, late 91-180 s). RESULTS: The mean temperature change (delta t degree C) during rewarming was 8.5 degrees C (SD 1.0 degree C) for gingival sites and 7.2 degrees C (SD 1.1 degrees C) for incisal sites. The slope of the 'best fit' straight line data enabled a rewarming index to be calculated for each site on each tooth. Linear regression analysis showed that the phase of rewarming was highly significant but the other variables were not. A one-way ANOVA showed no significant differences between or within groups. CONCLUSIONS: Three min is an appropriate time to record rewarming of teeth cooled for 20 s with an airstream at 20 degrees C. The side or site used to record surface temperatures using this technique is not significant. Rewarming is exponential and log transformation of the data produces a well-fitting straight line graph. The slope of this line provides a rewarming index which should enable comparison of TI and laser Doppler flowmetry in determining pulpal blood flow as a measure of tooth vitality.     

Studies in tooth crown temperature gradients with the use of infrared thermography

With the use of an infrared thermographic camera; temperature patterns over the crowns of teeth were recorded. The temperature of upper incisor teeth decreased from gingival margin to incisal edge by approximately 2.5 degrees C. Vital and nonvital teeth were the same temperature at rest, but after cooling with cold air, nonvital teeth were slower to rewarm than vital teeth. The infrared thermographic camera could provide a method of testing tooth vitality based on blood supply rather than nerve supply.     

Relations in color among maxillary incisors and canines.

OBJECTIVES: To establish the strength of color relation among the maxillary central incisor, lateral incisor and canine teeth by using digital photography. This relation might be useful for the color reconstruction of the missing part of a tooth from the color obtained from neighboring teeth. METHODS: The L*a*b* values of the maxillary incisors and canines were determined in 100 subjects. Paired t-tests, Pearson correlations and linear regression analyses were used to describe the relation of the L*a*b* values between the three teeth for each segment (cervical, middle and incisal). RESULTS: The mean L*a*b* values of the canines differed statistically significantly from the values of the central incisors (p<0.001) except for L* and a* values in the cervical segment between the lateral incisor and canine. The color differences between the incisors were statistically significant in fewer cases. The relation in color was the highest between the cervical segments of the three teeth, with respect to L* (r = 0.45-0.65; p < 0.001), b* (r = 0.49-0.55; p < 0.001), and a* (r = 0.38-0.61; p < 0.001), and no relation was found between the incisal segments of central incisor and canine. SIGNIFICANCE: There is a relation in color between the maxillary incisors and canines, which is stronger between the cervical than between the middle and incisal segments. Therefore, the color prediction is most reliable when the cervical parts of the teeth are used.     

Relationship between alignment conditions of teeth in anterior segments and incisal wear

This report describes the alignment condition and incisal wear of the anterior teeth in individuals 16–19 years of age. Tooth alignment and incisal wear were assessed on casts in accordance with two index systems NONAT (non-aligned tooth) and IwI (incisal wear index). Tests of the methods showed that the reproducibility of the assessments of tooth alignment and incisal wear were satisfactory. The results of the study of tooth irregularity demonstrated that the prevalence of non-alignment of one or more of the anterior teeth were much the same (∼50%) for the maxillary and mandibular jaws. The highest frequency was found for the maxillary lateral incisors and the mandibular central incisors (∼45%). A relationship between the alignment conditions and incisal wear of the anterior teeth was established. It appeared that non-alignment of one or more teeth in one or both jaws was associated with less severe incisal wear of the anterior teeth. This was most pronounced for non-aligned maxillary central incisors and non-aligned mandibular central incisors.     

Controlled orthodontic extrusion to create gingival papilla: a case report.

Prosthetic dental restorations alone do not produce esthetics. They must be in harmony with the surrounding gingiva, especially the gingival papilla. This case report describes the enhancement of the gingival papilla between an implant replacing the maxillary left central incisor and a provisional crown on the maxillary left lateral incisor. Esthetic harmony was disrupted by the absence of an interproximal papilla. First, provisional crowns on the implant and adjacent tooth were used in an attempt to remodel the interproximal gingival tissue, but the esthetic result was not satisfactory. The second attempt involved orthodontic extrusion of the lateral incisor in an incisal direction. The gingival tissue migrated incisally, thus restoring the deficient papilla and establishing restorative and gingival harmony. Both the implant and the lateral incisor were restored with ceramic crowns.     

Multiple dens invaginatus affecting maxillary lateral incisors and a supernumerary tooth

Abstract Dens invaginatus is a developmental variation resulting from an alteration in the normal growth pattern of the dental papilla of a tooth. This anomaly occurs predominantly in maxillary permanent lateral incisors. Multiple occurrence in maxillary incisor teeth in the same patient has frequently been reported, and examination of bilateral teeth for the anomaly is often carried out routinely. This paper reports an unusual case of multiple invaginations, including dens invaginatus affecting maxillary lateral incisors and a supernumerary tooth and minor imaginations of the upper canines. Moreover, the case illustrates the importance of examining all the teeth in patients who present with dens invaginatus and palatal pits in incisors and canines. The possibility that the supernumerary tooth had resulted from gemination of the lateral incisor tooth germ is discussed.     

Autotransplantation of premolars to replace maxillary incisors: a comparison with natural incisors.

The published literature contains no comprehensive studies that compare the outcome of premolar autotransplantation to the maxillary anterior region with natural incisors in the same patients. This article describes the gingival and periodontal conditions around premolars transplanted to the maxillary incisor region, subsequent to restoration. Forty-five premolars autotransplanted to the maxillary incisor region in 40 adolescent patients were evaluated after a mean observation period of 4.0 years. Mean age at surgery was 11.0 years. Established clinical criteria were used to assess tooth mobility, plaque and gingival indexes, probing pocket depth, and percussion. Recession and hyperplasia of interproximal gingival papillae were assessed according to a recently proposed index. Standardized radiography was used to evaluate presence of pathosis, pulp obliteration, root length, and crown-root ratios. Clinical variables for transplants did not differ from those of the natural incisors, except for increased mobility and more plaque in a few transplanted premolars. The interproximal gingival papillae adjacent to all transplanted teeth were normal or slightly hyperplastic. Radiographically, all transplants showed varying degrees of pulp obliteration, but no signs of pathosis. Crown-root ratios were similar for natural and transplanted teeth as were distances from cementoenamel junction to marginal bone. The overall status of the transplanted premolars and surrounding tissues indicated that this treatment modality may be recommended when maxillary incisors are missing in adolescents. In addition, tooth transplantation represents an inherent potential for bone induction and reestablishment of a normal alveolar process.     

Dens invaginatus on a geminated tooth: a case report

AIM: To present a case of a concomitant occurrence of dens invaginatus (DI) and gemination in a mandibular left lateral incisor. BACKGROUND: DI is a developmental anomaly resulting from the invagination of a portion of a crown in the enamel organ stage of odontogenesis. It is commonly found in the maxillary lateral incisors but also occurs in the central incisors, premolars, canines, and molars in descending order of frequency. The occurrence of DI in the mandible is extremely rare. Gemination results from one tooth bud attempting to split into two. Geminated teeth present with a single root structure and rarely occur in mandibular teeth. REPORT: A 13-year-old girl presented with a chief complaint of spontaneous nocturnal pain in the mandibular left lateral incisor tooth. Intraoral examination revealed the tooth was enlarged with a notch on the incisal edge extending to the coronal 1/3 of the crown. The radiological examination revealed a Type 2 DI in a Type I geminated mandibular left lateral incisor. SUMMARY: DI is clinically significant due to the possibility of the pulpal involvement; pulpitis, necrotic pulps, and chronic periapical lesions are often associated with this anomaly without clinical symptoms. Clinicians should be mindful of the possibility of DI when a tooth presents pulpitis without history of trauma or caries and examine the suspicious tooth and the periodontium radiographically.     

锥形束CT法在上颌前牙区牙龈厚度评估中的应用

目的 探究锥形束CT(CBCT)法在不同牙位、不同牙龈生物型及不同牙龈退缩类型上颌前牙区牙龈厚度评估中的应用。方法 选择2018年3月至2019年7月在我院口腔科接受CBCT检查的40例患者（225颗患牙）为研究对象，测量上颌前牙区龈缘下2 mm各患牙的牙龈厚度，比较其在不同牙位、牙龈生物型、牙龈退缩类型的差异。结果 中切牙的牙龈厚度（1.56±0.32） mm>侧切牙的牙龈厚度（1.34±0.28） mm>尖牙的牙龈厚度（1.13±0.24） mm；无退缩牙龈厚度（1.42±0.38） mm>退缩牙龈厚度（1.19±0.37） mm，退缩程度越深，牙龈厚度越小，差异具有统计学意义（P<0.05）；中切牙多为厚龈型，侧切牙和尖牙多为薄龈型；大部分患者为薄龈生物型，薄龈型相比厚龈型更容易发生牙龈退缩。CBCT法测量牙龈厚度具有准确性和可重复性。结论 CBCT法在上颌前牙区不同牙位、牙龈生物型及牙龈退缩类型上评估牙龈厚度具有良好的准确性。有助于牙科医生选择牙周治疗方案、评估美学修复预后提供参考依据。     

Detailed three-dimensional orthodontic tooth repositioning to improve restorative outcome:: A case report

The case describes the interdisciplinary treatment of a 23-year-old woman with a Class III malocclusion, missing an upper right lateral incisor, abrasion of the maxillary incisal edges, anterior gingival margin discrepancies, and gingival recession. Initially, the patient was treated with fixed appliances combined with orthognathic surgery. The extraction of the upper left lateral incisor and bilateral canine substitution plan was chosen. At the end of the surgical and orthodontic treatment, the restorative treatment with six veneers was accomplished to improve smile esthetics. Despite the missing lateral incisors, the patient showed a natural, good-looking final result. A symmetric incisal plane was established, a functional occlusion with average vertical and horizontal overlap was set, and the bone scallop and consequently the gingival margins were leveled. The interdisciplinary approach hid all of the initial esthetic defects of the case. The result highlights how to obtain a remarkable improvement of the smile outcome with a well-functioning masticatory system.     

Relationship between the width of the zone of keratinized tissue and thickness of gingival tissue in the anterior maxilla

The aim of this study was to evaluate whether there is a positive correlation between the width of the zone of gingival keratinized tissue and its thickness. Maxillary right canines, lateral incisors, and central incisors of 60 patients (30 men, 30 women) between the ages of 20 and 35 years were examined. Using an endodontic spacer with a rubber cursor and a digital caliper of 0.01-mm resolution, the values of the width of the zone of gingival keratinized tissue and gingival thickness were obtained. It was observed that the lateral incisor has the largest mean zone of gingival keratinized tissue (5.54 ± 1.09 mm), followed by the central incisor (4.62 ± 1.02 mm) and canine (4.32 ± 1.33 mm). The mean gingival thickness was greater in the central incisor (1.17 ± 0.20 mm), followed by the lateral incisor (1.04 ± 0.24 mm) and canine (0.87 ± 0.27 mm). No statistically significant difference was verified for the mean width of the zone of gingival keratinized tissue and gingival thickness between men and women. A positive correlation between gingival thickness and width of the zone of gingival keratinized tissue was observed in the maxillary canine (Pearson r = 0.398, P < .05), lateral incisor (Pearson r = 0.369, P < .05), and central incisor (Pearson r = 0.492, P < .05). In patients 20 to 35 years of age, there was a positive correlation between gingival thickness and width of the zone of gingival keratinized tissue for the maxillary right canine, lateral incisor, and central incisor.     

附件对隐形矫治器内收上前牙影响的三维有限元分析

目的    通过拔除上颌第一前磨牙后前牙内收的隐形矫治三维有限元模型,分析切牙上设置附件对牙齿移动方式的影响。方法    基于1例成年患者颌骨的锥形束CT影像数据,按照切牙上有无附件,构建4组拔除第一前磨牙的上颌隐形矫治模型,分别为切牙无附件组、侧切牙单附件组、中切牙单附件组和双附件组;导入Ansys Workbench三维有限元软件,设置4个上切牙控根压入内收的隐形矫治过程,分析牙列初始位移和附件的应力分布。结果    切牙无附件组及中切牙单附件组均发生4个切牙的舌向倾斜移动,后牙产生不同程度的近中倾斜移动,尖牙近中倾斜伴有伸长;侧切牙单附件组及双附件组切牙呈整体内收压入移动趋势,切牙附件的龈方可观测到压应力集中。结论    隐形矫治内收上前牙时,在侧切牙放置附件有助于切牙整体内收的表达,而中切牙附件对牙移动方式的影响较小。     

Incidence and distribution of root canal treatment in the dentition among a Jordanian sub population

AIM: To determine and compare the incidence of endodontically treated teeth in the maxilla and mandible, and to present the frequency of endodontic treatment for each tooth in the dentition in a group of the Jordanian population; then to compare these results with previously published surveys. METHOD: A total of 1,404 root canal treated teeth were examined clinically and radiographically. RESULTS: Most teeth were treated in a one visit procedure (40.1%). The results showed that 77.7% of the treated teeth were in the maxilla and 22.3% were in the mandible. Posterior teeth accounted for 39.0% of all treated teeth, among which, 20.3% were molars. The most frequently treated tooth was the maxillary central incisor tooth (39.6%), with the maxillary lateral incisor second (10.1%). Furthermore, the maxillary incisors alone accounted for almost half (49.7%) of the cases. The maxillary first molar was the third most frequently treated tooth (8.2%) with the mandibular first molar at 7.5%.The lowest frequency of treatment was for mandibular lateral incisors and canines which made up only 1.1% and 1.9% respectively. CONCLUSION: Comparison with previously published surveys revealed a lower percentage of molar endodontics than in other surveys.     

Bone augmentation and autogenous transplantation of premolar to the site of the fissure in a cleft palate patient

This article presents a case report of autogenous tooth transplantation to the site of the fissure, in addition to bone augmentation with graft of autogenous bone harvested from the iliac crest, performed in a cleft palate patient, who had insufficient bone volume. A non‐syndromic 10‐year‐old girl, with a unilateral cleft lip and palate, incisal transforamen fissures, agenesis of the maxillary left central incisor and both maxillary lateral incisors, was treated with autogenous bone graft in the cleft area. The orthodontic treatment plan was to replace the missing lateral incisors with the maxillary canines and to extract the mandibular first premolars. One of the mandibular premolars was extracted from its site with 2/3 of its root formation completed and transplanted to the maxillary left central incisor area. After orthodontic treatment, the anatomic crowns were characterized with composite resin. Autogenous tooth transplantation can be performed in the area of the fissure in young cleft palate patients, by performing bone graft augmentation before transplantation of the tooth, to gain sufficient recipient alveolar bone volume. A multidisciplinary approach is mandatory for the success of this clinical procedure, especially in cleft palate patients.     

A Study of Anterior Guidance

Purpose This study focuses on the curvature and inclination of the lingual surfaces of the maxillary anterior teeth from the transition point on the cingulum to the incisal edge. Materials and Methods On 32 sets of mounted casts, 768 measurements were made of the curvature of the lingual surfaces utilizing radius gauges. The inclination of the lingual surface relative to the occlusal plane was recorded. The relationship of the incisal edge of the mandibular teeth to the transition point on the cingulum of the maxillary teeth was determined. Centric occlusion contact was noted on each tooth. Results Significant differences were found between the measured areas of any one tooth and between the types of teeth. The average radius ranged from 20.5 mm on the mesial ridge of the canine to 5.3 mm in the fossa of the central. The average inclination of the lingual surfaces was 46%. In centric occlusion, 97% of the canines and 59% of the centrals and laterals were in contact with the opposing teeth. These contacts occurred 2.8 mm incisal to the transition point. The centrals contacted two opposing teeth (45%), and canines contacted one opposing tooth (53%). Conclusions The function and curvature of the incisor teeth vary considerably from those of the canines. Overcontouring the lingual surfaces of the maxillary incisors to gain contact is not normal and may be detrimental.     

The fusion of three primary incisors: report of case

The occurrence of a fusion of three primary incisors is rare. A two-year-old Japanese girl was brought to the pediatric dental outpatient clinic, Tokyo Dental College, to receive a caries-prevention treatment. The fused tooth consisted of the maxillary primary central incisors and right maxillary lateral incisor. Primary left lateral incisor erupted normally and the other primary teeth were erupted. The radicular pulp chambers were fused into one for three fourths of the length from the apex, and only one root. The hair and skin of the patient appeared normal and no systemic abnormality or congenital disease was noted in the medical history of the patient and her family. The occurrence of a three-tooth fusion, and no supernumerary tooth was confirmed.     

Equilibration of a progressive anterior open occlusal relationship: a clinical report

This clinical report described the initial phase of treatment of a progressive anterior open occlusal relationship. Trial equilibration on duplicate mounted diagnostic casts demonstrated centric contacts on all posterior teeth by reducing only the maxillary palatal cusps until the central incisors coupled. Anterior guidance and posterior teeth disclusion were confirmed with wax augmentation of maxillary canine palatal contours. Palatal surface and occlusal matrix reduction guides were used to visualize and measure the amount of planned tooth structure removal required to achieve a programmed occlusion. Intraoral composite resin augmentation of maxillary central incisor and canine palatal surfaces provided anterior guidance. Equilibration was limited to the maxillary palatal cusps and one lower molar. The initial 3 mm open dimension between the maxillary and mandibular incisors was eliminated. Accurate evaluation of the equilibrated duplicate casts resulted in a more conservative final result with less posterior tooth reduction and increased maxillary palatal contours. A comfortable and stable occlusion was established without any esthetic change prior to definitive restoration with multiple individual crowns.     

Multiple dens invaginatus in two brothers

Abstract Dens invaginatus is a developmental variation resulting from an alteration in the normal growth pattern of the dental papilla of a tooth. They predominantly occur on maxillary permanent lateral incisors. Their occurrence in several maxillary incisor teeth in an individual has been frequently reported, and the examination of bilateral teeth for the anomaly is well accepted. However, the present case illustrates the importance of examining both maxillary and mandibular incisors in patients who present with a dens invaginatus, in addition to other members of the family.     

Some periodontal tissue reactions to orthodontic tooth movement in monkeys

The purpose of the experiment reported was to study soft tissue changes at teeth which were orthodontically moved into areas with varying thickness and quality of periodontal tissues. The maxillary central incisors and first premolars in 5 adult monkeys were used as experimental teeth. 6 months prior to the start of the orthodontic treatment phase, the maxillary second premolars were extracted. By surgical means, areas with varying width of the keratinized gingiva were established in the incisor and premolar region. Following a clinical baseline examination which involved assessments of gingival width, location of the gingival margin in relation to cemento-enamel junction and probing attachment level, fixed orthodontic appliances were inserted in order to bodily move the two contral incisors in labial direction through the alveolar bone envelope and the first premolars in distal direction into contact with the first molars. Orthodontic forces were applied for a period of 3-4 months. The lateral incisors and first molars were selected as non-moved control teeth. After the experimental teeth had been retained in their new positions for 1 month, the clinical examination was repeated. Tissue blocks containing test and control specimens were subsequently dissected and prepared for microscopic analysis. The analysis included histometric assessments of loss of connective tissue attachment and height of alveolar bone. The results showed that at every second labially moved incisor, the gingival margin had become displaced in apical direction. The degree of displacement, however, was small and only at 2 teeth accompanied by loss of connective tissue attachment. Throughout the study, these particular teeth also showed obvious signs of gingival inflammation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Management of subluxation injury in a thumb-sucking child: a case report

Abstract –  This case report presents use of a custom trauma splint that was fabricated to prevent excessive thumb-sucking trauma to a previously-subluxated permanent incisor. A 10-year-old boy was referred to the clinic 10 days after falling in the schoolyard that resulted in a trauma to his maxillary left central incisor. The extent of clinical mobility stipulated fabrication of a custom trauma splint that would prevent further trauma to the incisor caused by excessive pressure of the thumb. A light-cured resin composite splint, covering the incisal edges of the central incisors and labial surfaces of the lateral incisors was made, and approximately 1-mm composite within the impressions of central incisors were trimmed off. The splint was bonded to the neighboring lateral incisors with flowable resin composite and root canal therapy was initiated on the subluxated incisor. After one week, the patient stopped his sucking habit completely. The treatment not only allowed for complete healing of the subluxated incisor without being exposed to further trauma, but also for spontaneous eruption of the tooth and closure of the existing open-bite.