Case report and literature review of vital pulp preservation by endodontic microsurgery at the distal buccal root of maxillary molar / 口腔疾病防治

Objective@#To investigate the diagnosis, treatment and prognosis of nonodontogenic periapical lesions and to provide a reference for clinical diagnosis and treatment.@*Methods@# A case of a patient with right upper molar pulp with apical penetration and local occlusion admitted to the West China Stomatological Hospital of Sichuan University was retrospectively analyzed, and the curative effect of microapical surgery and pith preservation was also analyzed.@*Results @#The imaging features of tooth 16 showed periradicular radiolucency combined with local radiopaque lesions around the distal buccal apical area. Endodontic microsurgery was performed under local anesthesia. Soft tissue coverage was observed in the distal buccal apical area during the surgery, and no radiopaque tissue was detected. The distal buccal root apex was cut by 3 mm, and mineral trioxide aggregate was used for root-end backfilling. The postoperative pathological results revealed fibrous connective tissue. One-week recall X-ray examination showed tight root-end backfilling and no periradicular radiolucency; an electrical test of pulp vitality showed positive results. The four-year follow-up showed that there was no discoloration in tooth 16 and no significant difference in thermal and electrical tests of pulp vitality compared with control teeth. Combining the clinical manifestations, imaging features, surgical exploration results and pathological reports, the case was most likely to be cemental hypoplasia. Through the literature review, the treatment and healthy pulp preservation of such cases by endodontic microsurgery under the premise of preserving teeth has not been reported.@*Conclusion@#For maxillary posterior teeth with periapical lesions but healthy pulp, accurate estimation of pulp status, endodontic microsurgical exploration and application of bioactive materials can achieve vital pulp preservation while removing the lesions.

Radiological features of synovial chondromatosis affecting the temporomandibular joint: report of three cases.

Synovial chondromatosis is a benign nodular cartilaginous proliferation that mainly occurs in large joints. The temporomandibular joint is considered to be rarely affected. Several cases of synovial chondromatosis of the temporomandibular joint have been reported with clinical and histological features. People with this disease may present with swelling, pain, intracapsular sounds, and limitation of mandibular movement. Radiographs are an important component in the diagnostic process for synovial chondromatosis. In this article, we report three cases of synovial chondromatosis occurring in the temporomandibular joint with a focus on the radiological features, including those on plain films, cone-beam computed tomography (CT) images, and conventional CT images. The three cases had totally different radiological features. The imaging differences were analyzed and compared to create combined diagnostic methods based on clinical features and examination techniques. The role of cone-beam CT examination in the diagnosis of the disease is discussed.

[Oral treatment for obstructive sleep apnea syndrome].

Obstructive sleep apnea syndrome (OSAS) is a common clinical disease with high incidence and low treating proportion, difficult evaluation, and complicated nosogenesis. OSAS can cause systematic impairments. Various treatment methods were applied in clinical setting with the tendency of cross-disciplinary promotion. Oral treatment plays an exceedingly important role in OSAS research and therapy. This study reports the oral treatment involving OSAS therapy.

Cone-beam computed tomography evaluation of the maxillofacial features of patients with unilateral temporomandibular joint ankylosis undergoing condylar reconstruction with an autogenous coronoid process graft.

OBJECTIVE: To evaluate the changes in the jaws and the upper airways of unilateral temporomandibular joint ankylosis patients who underwent condylar reconstruction via autogenous coronoid process grafts using cone-beam computed tomography (CBCT). STUDY DESIGN: The 27 included patients underwent CBCT examinations at three stages: T0 (within two weeks before surgery), T1 (two weeks after surgery), and T2 (an average of 13 months after surgery). Forty items related to the maxillofacial hard tissues and the upper airway collected at the three times and the coronoid process graft volumes after surgery were compared. RESULTS: Some integral items related to the mandibular hard tissues exhibited statistical difference shortly after surgery. Some integral items related to maxillofacial hard tissues changing obviously long period after surgery may result from graft remodeling. Asymmetry-related item regarding local neo-condyle and some airway items were significantly different between T0 and T1. Due to variations in graft remodeling, some related local asymmetry items and airway items differed significantly between T0 and T2. CONCLUSIONS: Anteriorly and inferiorly located neo-condyles and a trend toward the pronation of the mandible were observed and the narrowness of the upper airway was improved shortly after surgery. The grafts remodeled differently and some integral and asymmetry items related to neo-condyle changed. The improvements in the upper airway were slightly reduced.

Characteristic features of the odontogenic myxoma on cone beam computed tomography.

OBJECTIVES: To illustrate the characteristic features of odontogenic myxoma (OM) on CBCT. METHODS: From 52 subjects with histopathologically diagnosed OMs, 18 subjects who underwent a CBCT examination were retrieved between May 2009 and April 2016. Features on CBCT images and clinical records were carefully observed and analyzed. RESULTS: Characteristic features include: (1) fine and straight septa that were recognized to separate the tumour into triangular, square or rectangular spaces, which appeared as "tennis racket" or "honeycomb" patterns; (2) septa that frequently scattered to the borders of lesions and appeared perpendicular to the margins; (3) tooth displacement and resorption that were seen in most of the OM lesions; (4) OMs that were noted to have a tendency to involve the alveolar process, scallop between the roots and affect the integrity of the alveolar ridge; (5) the cortex of OMs that appeared normally perforated and the edge of the cortex expanded into the soft tissue. CONCLUSIONS: CBCT is highly effective in demonstrating the comprehensive internal structures of the lesions precisely and providing detailed information for the diagnosis of OM.

[Analysis of clinical and imaging findings in cementoblastoma].

OBJECTIVE: To assess the clinical and imaging features of cementoblastoma for diagnosis and differential diagnosis. METHODS: Clinical and imaging data of 14 cases were selected for this retrospective study. RESULTS: A total of 14 cases of cementoblastoma patients with ages at diagnosis ranging from 11 years to 58 years (mean age, 27.6 years; median age, 21.0 years). The tumor affected 7 patients from each gender. The mandible was the main site of occurrence. The most common complaints were swelling and pain. Radiographic results showed that cementoblastoma typically presented as a well-circumscribed and radiopaque mass confluent with the involved tooth root and surrounded by a thin and uniform radio-lucent border. Tumor parenchyma was generally mixed-density, which could be divided into two types, namely, homogeneous and heterogeneous patterns. Other significant imaging features included the periphery bone of the lesion sclerosis and cortical thickening of the lower edge of the mandible. CONCLUSION: Obvious characteristics are found in the clinical and imaging findings of cementoblastoma. Accurate recognition of this lesion is significant in clinic to avoid misdiagnoses.

[Cone-beam CT features of ameloblastomas].

OBJECTIVE: To summarize and analyze the cone-beam CT (CBCT) imaging features of ameloblastomas for clinical preoperative diagnosis. METHODS: Thirty-seven cases with complete data proven by pathology were retrospectively studied for distinct CBCT features. RESULTS: Of the 37 cases, 31 were primary and 6 were recurrent. On CBCT images, the 37 cases were composed of 36 cases (97.3%) of intraosseous lesions (17 cases of multilocular lesions, 17 cases of unilocular lesions, and 2 cases of honeycomb lesion) and 1 case (2.7%) of extraosseous lesion (soft tissue lesion). Of the 17 multilocular cases, 15 (88.2%) showed tongue-shaped crests in lesions. Thirty-four cases (94.4%) showed apparent expansible change toward lip/buccal and (or) palatal/lingual sides ofjaw, with partialcortical erosion. CONCLUSION: CBCT imaging yields accurate three-dimensional images of lesion shape and structure. Therefore, CBCT can be usedfor the clinical diagnosis and surgical assessment of ameloblastoma.

Cone beam computed tomography signs of desmoplastic ameloblastoma: review of 7 cases.

OBJECTIVE: This study aimed to evaluate and summarize the radiographic features of desmoplastic ameloblastoma (DA) on cone beam computed tomography (CBCT) scans and to provide necessary further information for clinical diagnosis and preoperative assessment. STUDY DESIGN: Seven cases with pathologic diagnosis of DA were studied retrospectively. A CBCT scan of each individual was analyzed and compared with its corresponding plain (panoramic) radiograph. RESULTS: We found that 71.4% of lesions were located in the anterior or premolar regions (or both) and showed root displacement. With the advent of CBCT imaging, most DA lesions (57.1%) were perceived as having honeycomb appearance totally or dominantly. Distinctively, all the lesions presented cortical expansion with perforation in the buccal/labial side. CONCLUSIONS: The typical intralesional structure with honeycomb appearance and the dominant buccal/labial cortical expansion with perforation could be proposed as the characteristic features of DA on CBCT images. CBCT can provide more information for preoperative radiologic assessment of DA compared with panoramic radiography.

[Foundation of the interactive oral and maxillofacial radiological image annotation database].

OBJECTIVE: This project aims to establish an interactive oral and maxillofacial radiological image annotation database and to analyze its feasibility for implementation into curricula in order to develop a highly effective software for image browsing. METHODS: We established the interactive image annotation database primarily on the basis of the local network and Foxit Reader. A pilot survey was then conducted to determine the performance of the interactive database. Seventy-six students were asked to complete a structured and open questionnaire related to their perceptions of using the database. Simple numeric quantitative and qualitative analyses were then applied. RESULTS: A total of 542 portable document format (PDF) digital teaching images and corresponding annotated files were collected. The survey revealed that most of the students found the database useful. Approximately 87.50% of the 64 subjects who compelete questionnaire believed that the database was superior to an older system (joint photographic experts group, JPEG) of image browsing. CONCLUSION: The integration and sharing of teaching resources and the establishment of an internet-based learning platform is the key to realizing a digital medical teaching system. The established database has high potential in a wide range of practical applications.

Analysis of the correlative factors for velopharyngeal closure of patients with cleft palate after primary repair.

OBJECTIVE: The objective of this study was to analyze the correlative factors for velopharyngeal closure of patients with cleft palate after primary repair. STUDY DESIGN: Ninety-five nonsyndromic patients with cleft palate were enrolled. Two surgical techniques were applied in the patients: simple palatoplasty and combined palatoplasty with pharyngoplasty. All patients were assessed 6 months after the operation. The postoperative velopharyngeal closure (VPC) rate was compared by χ(2) test and the correlative factors were analyzed with logistic regression model. RESULTS: The postoperative VPC rate of young patients was higher than that of old patients, the group with incomplete cleft palate was higher than the group with complete cleft palate, and combined palatoplasty with pharyngoplasty was higher than simple palatoplasty. Operative age, cleft type, and surgical technique were the contributing factors for postoperative VPC rate. CONCLUSIONS: Operative age, cleft type, and surgical technique were significant factors influencing postoperative VPC rate of patients with cleft palate.

[Evaluation of cone-beam CT in diagnosis of supernumerary teeth in the anterior maxilla].

OBJECTIVE: To evaluate the value of cone-beam CT (CBCT) in the diagnosis and orientation of supernumerary teeth in the anterior maxilla. METHODS: 195 supernumerary teeth in the anterior maxilla of 146 patients were included, which were examined by CBCT. The number, shape, size, 3-dimensional position, growth direction of the supernumeraries and their relationship with the neighboring teeth were analyzed. RESULTS: The 146 patients aged from 5 to 39, and males were affected more than females in a ratio of 2.95:1. 102 (69.9%) patients had single supernumerary teeth. Of the 195 supernumerary teeth, 126 (64.6%) were near the middle line, 131 (67.2%) were conical, 51 (26.2%) were curved root, 98 (50.3%) were inverted and had a length of (11.97 +/- 2.40) mm. The supernumerary teeth often caused complications. CONCLUSION: The position of the supernumerary teeth is varied in the maxilla, and often causes permanent dentition complications. CBCT imaging yields accurate 3-dimensional pictures of supernumerary teeth, local dental and bony structures, which is helpful for diagnosis and orientation of supernumerary teeth.

Associations between maxillary sinus mucosal thickening and apical periodontitis using cone-beam computed tomography scanning: a retrospective study.

INTRODUCTION: This study evaluated the pathologic and spatial associations between apical periodontitis of the maxillary premolars/molars and the maxillary sinus mucosal thickening using cone-beam computed tomography (CBCT) scanning. METHODS: CBCT images of 372 patients with 508 exposed maxillary sinuses were inspected retrospectively. Clinical features such as sex and age of the patients and pathologic findings of the maxillary sinus and adjacent teeth were recorded, graded, and analyzed. RESULTS: Maxillary sinus mucosal thickening was found in 180 (48.4%) patients and 235 (46.2%) sinuses. The prevalence of maxillary sinus mucosal thickening increased dramatically as the severity of apical periodontitis increased (from 41.5% in those without periodontal disease to 100%). However, the nature of the spatial relationship between the maxillary sinus floor and the infected root tips or between the sinus floor and periapical lesions did not appear to have an effect on the prevalence of maxillary sinus mucosal thickening. Patients over 60 years of age had the highest prevalence of maxillary sinus mucosal thickening. CONCLUSIONS: A retrospective inspection of CBCT images revealed that the prevalence and severity of maxillary sinus mucosal thickening were positively associated with the degree of apical periodontitis. CBCT imaging is applicable for the evaluation of the maxillary sinuses and adjacent teeth.

A comparative analysis of periapical radiography and cone-beam computerized tomography for the evaluation of endodontic obturation length.

OBJECTIVE: The aim of this study was to determine the consistency and inconsistency between the periapical radiography (PR) and cone-beam computerized tomography (CBCT) in evaluating the length of root canal obturations (RCOs) in vivo. STUDY DESIGN: Thirty-six maxillary and mandibular first and second molars yielding 109 obturated root canals with available PR and CBCT images were analyzed. The inclusion criterion was that the RCO extended 0-2 mm short of the radiographic apex on PR images. Teeth having root canal calcification, apical resorption, or poor quality PR/CBCT images were excluded. Agreement and disagreement between the 2 imaging modalities for obturation length were analyzed using the χ(2) test. RESULTS: A total of 30.3% of the RCOs evaluated by PR as having adequate length were diagnosed by CBCT to have inadequate length. Among these, 13.8% were overextended and 16.5% underextended as diagnosed by CBCT. When the distance from the filling tip to the radiographic apex was 0.5 to 1 mm on the PR image, the discordance rate was the lowest (11.1%) in all evaluated distance groups, significantly lower than with distances of 0-0.5 mm and 1.5-2 mm (P < .01). When RCOs were diagnosed as terminating at the facial/lingual side, overextension was the main evaluation result by CBCT in the disagreement evaluation with PR and significantly more frequent than those at the mesial/distal/central side (P < .01). CONCLUSIONS: CBCT evaluated 30.3% of the RCOs with radiographically adequate length as inadequate. When the RCOs radiographically terminated 0.5-1 mm short of the apex, the evaluation rated adequate for obturation length was comparatively reliable.

Study of relationship between clinical factors and velopharyngeal closure in cleft palate patients.

BACKGROUND: This study was carried out to analyze the relationship between clinical factors and velopharyngeal closure (VPC) in cleft palate patients. METHODS: Chi-square test was used to compare the postoperative velopharyngeal closure rate. Logistic regression model was used to analyze independent variables associated with velopharyngeal closure. RESULTS: Difference of postoperative VPC rate in different cleft types, operative ages and surgical techniques was significant (P=0.000). Results of logistic regression analysis suggested that when operative age was beyond deciduous dentition stage, or cleft palate type was complete, or just had undergone a simple palatoplasty without levator veli palatini retropositioning, patients would suffer a higher velopharyngeal insufficiency rate after primary palatal repair. CONCLUSIONS: Cleft type, operative age and surgical technique were the contributing factors influencing VPC rate after primary palatal repair of cleft palate patients.

Evaluation of the root and canal morphology of mandibular first permanent molars in a western Chinese population by cone-beam computed tomography.

INTRODUCTION: The purpose of this study was to evaluate the root and canal morphology of mandibular first permanent molars in a western Chinese population by using cone-beam computed tomography (CBCT). METHODS: In this study, 558 samples were examined by CBCT. Details of sex, tooth position, the number of roots and canals, and the canal configuration were recorded. The root canal configuration was categorized and compared according to Vertucci's criteria. RESULTS: Overall, 51.4% of the mandibular first permanent molars examined had four canals, and 25.8% had a separate distolingual root. In 48.1% of these, the fourth canal was in the separate distolingual root. In the two-rooted mandibular first permanent molars, 93.9% of the mesial root canals were of type IV, and 62.9% of the distal root canals were of type I. In the three-rooted samples, 94.4% of the mesial root canals were of type IV, and 98.6% of the distobuccal and 100% of the distolingual root canals were of type I. In addition, there was a higher incidence of three-rooted mandibular first permanent molars on the left side than on the right, but this relationship was not significantly correlated with sex. CONCLUSIONS: Mandibular first permanent molars commonly have four canals and a higher prevalence for a separated distolingual canal in a western Chinese population.

A cone-beam computed tomography study of maxillary first permanent molar root and canal morphology in a Chinese population.

AIM: This study evaluated root and canal morphology of permanent maxillary first molars in a Chinese population using cone-beam computed tomography scanning. METHODOLOGY: The sample included 775 cone-beam computed tomography images of maxillary first molars; 627 of the subjects had unilateral qualifying molars and 74 had bilateral qualifying molars. The following observations were made: (1) frequency of root and canal numbers, (2) frequency of additional canals in the mesiobuccal root by sex, age, and tooth position, and (3) unilateral and bilateral occurrence of additional canals in the mesiobuccal root. RESULTS: Fused roots were present in 2.71% of unilateral qualifying molars. Multiple canals were present in the following frequencies: two canals in 0.31%, three canals in 47.21%, four canals in 50.40%, five canals in 1.75%, and six canals in 0.31% of teeth. Additional canals were detected in 52.24% of mesiobuccal roots, 1.12% of distobuccal roots, and 1.76% of palatal roots. Patients aged 20 to 30 years showed a higher prevalence of additional mesiobuccal root canals. This prevalence did not differ with sex and tooth position. Most (71.11%) of the additional mesiobuccal root canals in subjects with bilateral qualifying molars were symmetric. CONCLUSION: Cone-beam computed tomography scanning is an effective method for studying external and internal dental morphology. The root and canal configurations of maxillary first molars in this Chinese population were consistent with previously reported data. More attention should be given to the detection of additional canals in patients between 20 and 30 years of age. These data may facilitate successful endodontic treatment.

[Investigation of the optimized surgical procedure for the cleft palate patients over six years old].

OBJECTIVE: To establish the optimized surgical procedure in our approach to treat the velopharyngeal insufficiency and improve the articulations of the patients with cleft palate over six years old. METHODS: Thirty-seven subjects over six years (including six years) old underwent the palatoplasty and sphincter pharyngoplasty simultaneously. We assessed the outcome of the surgery by perceptual speech assessment, nasopharyngoscopy and lateral cephalogram 10 to 15 months postoperatively. RESULTS: Twenty-two subjects got complete velopharyngeal closure. The velopharyngeal closure ratio of 15 subjects were over 85% according to the findings of the nasopharyngoscopy. Lateral cephalograms reveal that all the subjects could get their velars raised and well contacted with the posterior pharyngeal wall in dynamic condition. Perceptual speech assessment: The rate of hypernasality and nasal emission decreased significantly, and the consonant articulation increased. CONCLUSION: Our surgical procedure in this study corrected the velopharyngeal insufficiency and improved the articulation of the patients over six years old significantly.

[Usage status of periapical films undertaking in root canal treatment].

OBJECTIVE: To determine the current radiographic practices of root canal treatment (RCT) undertaken by endodontists, general dentist practitioners (GDPs) and interns, and to analyze the relationship between the usage of periapical films and the quality of RCT. METHODS: The patients who had received RCT treatment in West China College of Stomatology were investigated at random and were divided into three groups: Endodontists treating group, GDPs treating group and interns treating group according treating physician. The usage status of periapical film were investigated by the well designed questionnaires. The obturation quality of postoperative films were evaluated. Chi-square analysis was used to compare usage rates of periapical films of three groups. Mann-Whitney test was used to determine the relationship between the usage of periapical films and the quality of RCT. RESULTS: 571 teeth of 412 patients were investigated. In endodontists treating group, GDPs treating group and interns treating group, the usage rates of preoperative films were 95.3%, 89.5% and 92.1% respectively. The usage rates of working length films were 5.2%, 1.1% and 5.8% respectively. The usage of master point films was 94.8%, 72.1% and 97.4% respectively. The usage of postoperative films was 97.9%, 76.3% and 95.3% respectively. There were statistically significant differences among the working length films, master point films and postoperative films of three groups (P<0.05). The periapical films of adequate quality RCT and inadequate quality RCT were 3.14+/-0.639 and 2.84+/-0.736 respectively. There was statistically significant difference between periapical films of adequate quality RCT and inadequate quality RCT (P<0.05). CONCLUSION: Radiographic practices of endodontists and interns are more standardized than GDPs. Quality RCT is related to radiographic practices. Standard radiographic practices would be benefit to RCT.

[Effect of root canal curvature on canal length measurement on digital image of human lower mandibular permanent incisor].

OBJECTIVE: To investigate the effect of canal curvature on measured precision in canal length of human lower mandibular permanent incisors imaged by direct digital radiograph. METHODS: With Trophy digital X-ray system, 299 Chinese lower mandibular permanent incisors were selected to take the direct digital X-ray photography in both facial to lingual (L-T) and proximal directions (M-D). Two operators familiar with endodontic knowledge estimated the canal length by means of on-screen DDR with 2-and 3-click measurements. RESULTS: The true canal length of Chinese lower mandibular permanent incisors was (19. 54 +/- 1.62) mm. The tooth root canal length on digital image was overestimated with 3-click measurement (P < 0.05), and the canal length with 2-click measurement was almost similar to the true canal length from the facial-lingual direction X-ray photography (P > 0.05). The less than 1 mm difference between the estimated canal and the true canal length was above 95%. The canal length was underestimated with 2-click measurement as the curvature severity increased. CONCLUSION: Direct digital radiography system is applicable to estimate the canal length in clinic as the accuracy is very good. The curved canal length should be estimated with 3-click measurement.

[Comparative research of craniofacial structural characteristics of syndromic and non-syndromic patients with cleft palate].

OBJECTIVE: To compare craniofacial structural characteristic of syndromic and non-syndromic patients with cleft palate and to probe into the reason of their maxillary hypoplasia and to lay a foundation for better treatment protocol for syndromic patients with cleft palate. METHODS: The sample consisted of 8 individuals with Treacher Collin syndrome, 9 patients with Pierre Robin syndrome, and 40 patients with non-syndromic cleft palate which met certain criterions. Lateral cephalometric radiographs were obtained from each study subject. A total of 18 variables, comprising 9 angular, 7 linear, and 2 ratio measurements, were studied. SPSS 12.0 software was used to describe the statistics data, consisting of means, SD, and t test. RESULTS: The tendency for smaller value in SNB and larger value in ANB indicate a severer anteroposterior mandibular hypoplasia in the syndromic type cleft. There was no difference between syndromic and non-syndromic cleft palate patients with regards to maxillary anteroposterior development. No significant difference on the development in cranial base area was found either. CONCLUSION: This interplay of cranio-facial bones is very important in the development of this complex, which will not only affect the growth but also the defect development. In this study, the patients with the two syndromes showed the similar growth potential of maxilla with the non-syndromic cleft patients.