BACKGROUND Extraction of impacted third molars often leads to severe complications caused by damage to the inferior alveolar nerve(IAN).AIM To proposes a method for the partial grinding of an impacted mandibular third...BACKGROUND Extraction of impacted third molars often leads to severe complications caused by damage to the inferior alveolar nerve(IAN).AIM To proposes a method for the partial grinding of an impacted mandibular third molar(IMM3)near the IAN to prevent IAN injury during IMM3 extraction.METHODS Between January 1996 and March 2022,25 patients with IMM3 roots near the IAN were enrolled.The first stage of the operation consisted of grinding a major part of the IMM3 crown with a high-speed turbine dental drill to achieve sufficient space between the mandibular second molar and IMM3.After 6 months,when the root tips were observed to be away from the IAN on X-ray examination,the remaining part of the IMM3 was completely removed.RESULTS All IMM3s were extracted easily without symptoms of IAN injury after extraction.CONCLUSION Partial IMM3 grinding may be a good alternative treatment option to avoid IAN injury in high-risk cases.展开更多
Background:This study aims to predict the extraction difficulty of mandibular third molars based on panoramic images using transfer learning while employing super-resolution(SR)technology to enhance the feasibility an...Background:This study aims to predict the extraction difficulty of mandibular third molars based on panoramic images using transfer learning while employing super-resolution(SR)technology to enhance the feasibility and validity of the prediction.Methods:We reviewed a total of 608 preoperative mandibular third molar panoramic radiographs from two medical facilities:the First Affiliated Hospital of Zhengzhou University(n=509;456 in the training set and 53 in the test set)and the Henan Provincial Dental Hospital(n=99 in the validation set).We conducted a deep-transfer learning network on high-resolution(HR)panoramic radiographs to improve the longitudinal resolution of the images and obtained the SR images.Subsequently,we constructed models named Model-HR and Model-SR using high-dimensional quantitative features extracted through the Least Absolute Shrinkage and Selection Operator method.The models’performances were evaluated using the receiver operating characteristic curve(ROC).To assess the reliability of the model,we compared the results from the test set with those of three dentists.Results:Model-SR outperformed Model-HR(area under the curve(AUC):0.779,sensitivity:85.5%,specificity:60.9%,and accuracy:79.8%vs.AUC:0.753,sensitivity:73.7%,specificity:73.9%,and accuracy:73.7%)in predicting the difficulty of extracting mandibular third molars.Both Model-HR(AUC=0.821,95%CI 0.687–0.956)and Model-SR(AUC=0.963,95%CI 0.921–0.999)demonstrated superior performance compared to expert dentists(highest AUC=0.799,95%CI 0.671–0.927).Conclusions:Model-SR yielded superior predictive performance in determining the difficulty of extracting mandibular third molars when compared with Model-HR and expert dentists’visual assessments.展开更多
We present a case of a patient with rare anatomy of a maxillary second molar with three mesiobuccal root canals and a maxillary third molar with four separate roots, identified using multi-slice computed topography ...We present a case of a patient with rare anatomy of a maxillary second molar with three mesiobuccal root canals and a maxillary third molar with four separate roots, identified using multi-slice computed topography (CT) and three-dimensional reconstruction techniques. The described case enriched/might enrich our knowledge about possible anatomical aberrations of maxillary molars. In addition, we demonstrate the role of multi-slice CT as an objective tool for confirmatory diagnosis and successful endodontic management.展开更多
[Objectives] To shorten the time of removal of the bone embedded mandibular third molar,reduce the complications of tooth extraction,and explore a surgery method of resistance-free removal of the mandibular third mola...[Objectives] To shorten the time of removal of the bone embedded mandibular third molar,reduce the complications of tooth extraction,and explore a surgery method of resistance-free removal of the mandibular third molar. [Methods] A total of 50 patients with bone embedded mandibular third molar needing to be removed were selected. A 45° elevation turbine and a long tungsten steel drill were used to remove the mesial,buccal,and distal resistances. When necessary,tongue side and root resistance was removed,and the third molar was removed when there was basically no resistance around it. The removal time was recorded,followed up for 10 d,and the postoperative reaction was observed. [Results] The bone embedded mandibular third molars were removed for all patients within 15 min,and there was no serious postoperative reaction,all patients showed high satisfaction. [Conclusions]The method of resistance-free removal of the bone embedded mandibular third molar can significantly shorten the removal time,reduce the fear of patients,and ease pain of patients.展开更多
BACKGROUND Morphological anomalies of teeth,including talon cusp,dens evaginatus,gemination,fusion,concrescence,root dilaceration,and taurodontism,always involve changes in the enamel,cementum and dentin.Diagnosing co...BACKGROUND Morphological anomalies of teeth,including talon cusp,dens evaginatus,gemination,fusion,concrescence,root dilaceration,and taurodontism,always involve changes in the enamel,cementum and dentin.Diagnosing concrescent teeth through routine clinical examination alone is difficult,and most cases of concrescence are found accidentally during extraction.A definite preoperative diagnosis of concrescence would contribute to a better treatment plan and fewer undesirable complications CASE SUMMARY A 47-year-old woman who complained of left maxillary first molar loss for half a year presented to our department seeking treatment by dental implant restoration.Panoramic radiography and cone-beam computed tomography(CBCT)showed an unclear boundary between the distal root of the second molar and the mesial root of the third molar.The teeth were extracted under local anesthesia,and a definite diagnosis of concrescence was made by histopathological examination.CONCLUSION CBCT is a useful tool for diagnosing and planning the management of tooth concrescence and may be beneficial for reducing unnecessary complications.展开更多
Double teeth refer to two teeth that are totally or partially joined by dentin and maybe their pulps. These developmental anomalies may be the result of either gemination or fusion. This is a case of a 15-year-old Ind...Double teeth refer to two teeth that are totally or partially joined by dentin and maybe their pulps. These developmental anomalies may be the result of either gemination or fusion. This is a case of a 15-year-old Indo-Trinidadian male who presented with the fusion of a mandibular third molar with a distomolar as an incidental finding. The patient had his general dental care provided by a paediatric dentist and was referred to an oral and maxillofacial radiologist, orthodontist, and oral surgeon for consultation. A Cone-beam CT was taken to supplement the plain film periapical and orthopantomogram radiographs. It showed the three-dimensional orientation of the double molar and the extent of joining. This is the first case of fusion of a mandibular third molar to a distomolar being reported in the Caribbean.展开更多
Kissing molars (KMs) is a condition of occlusal molar surfaces in a single follicular space with roots extending in opposite directions. Here, we have reported a case of KMs in a 58-year-old woman. The patient complai...Kissing molars (KMs) is a condition of occlusal molar surfaces in a single follicular space with roots extending in opposite directions. Here, we have reported a case of KMs in a 58-year-old woman. The patient complained of pain in the right mandibular molar region and was diagnosed with KMs consisting of the right mandibular second and third molars. Because of the patient’s pain having subsided at the time of the visit and her unwillingness to undergo tooth extraction, the patient was followed up. KMs is classified into three classes (I-III) and is either true-KMs or pseudo-KMs and presents with or without cystic variants of dental follicles. The presents as true-KMs class II without a cystic variant. With reference to the literature and based on our analysis, the mean age of patients affected by this specific case of KMs is 31.7 years and unilateral KMs is relatively more common (85.7%). Histopathological findings of dentigerous cysts are more often indicated (42.9%). The treatment policy for KMs should therefore be based on the classification of KMs. Importantly, the focus should be on preserving the first and second molars as much as possible. The treatment approach, such as the employment of surgical removal or orthodontics, should be determined by considering the associated factors such as the crowns, tissues, and age of the patient.展开更多
Teeth affect not only oral problems but also facial morphology.In China,there are few reports about the influence of the third molars on the craniofacial morphology of Han youths.Using in vivo imaging software,3D reco...Teeth affect not only oral problems but also facial morphology.In China,there are few reports about the influence of the third molars on the craniofacial morphology of Han youths.Using in vivo imaging software,3D reconstruction of craniofacial CTs were performed on 32 Chinese Han youths without mandibular third molars and 25 Chinese Han youth with full mandibular third molars.The morphology of their mandible and mandibular tissue was measured to identify differences.Among the morphological characteristics of hard tissues,except for∠ANB,people with a full eruption of the mandibular third molars had statistically significantly larger angle indicators than people without the eruption of the third molars.The soft tissue indicators also showed statistically significant discrepancies in terms of morphological facial height,mouth to gnathion distance,lip height,and mouth breadth.The most influential index for mandibular third molars was length of symphysis,followed by the four indicators of soft tissue and mandible length and height.Morphology facial height,mouth to gnathion distance,lip height,and height of symphysis were moderately correlated.The experimental results show that among Han youth in North China,the third molar eruption has a widespread influence on mandibular morphology,especially in angle,length,and height indicators.It also has a certain influence on maxillofacial soft tissue morphology.These results can be applied to future clinical risk assessment of the wisdom teeth and forensic personal identification of the cranial and maxillofacial region.展开更多
This paper reported a case of fusion between an impacted third molar and a supernumerary tooth, in which a surgical intervention was carried out, with the objective of removing the dental elements. The panoramic radio...This paper reported a case of fusion between an impacted third molar and a supernumerary tooth, in which a surgical intervention was carried out, with the objective of removing the dental elements. The panoramic radiography was complemented by the Donovan's radiographic technique; but because of the proximity of the dental element to the mandibular ramus, it was not possible to have a final fusion diagnosis. Hence, the Cone-Beam Computed Tomography--which provides precise three- dimensional information--was used to determinate the fusion diagnosis and also to help in the surgical planning. In this case report we observed that the periapical, occlusal and panoramic were not able to show details which could only be examined through the cone-beam computed tomo- graphy.展开更多
The role of third molars in the oral cavity has been extensively studied over the years. Literature includes numerous diagnostic and treatment alternatives regarding the third molars. However, an issue that has not be...The role of third molars in the oral cavity has been extensively studied over the years. Literature includes numerous diagnostic and treatment alternatives regarding the third molars. However, an issue that has not been discussed at the same level is their involvement in orthodontic therapy. The aim of this study is to present a review of the contemporary literature regarding the most broadly discussed aspects of the multifactorial role of third molars in orthodontics and which are of general dental interest too.展开更多
Considering the adverse effects of nonimpacted third molars(N-M3s)on the periodontal health of adjacent second molars(M2s),the removal of N-M3s may be beneficial to the periodontal health of their neighbors.This study...Considering the adverse effects of nonimpacted third molars(N-M3s)on the periodontal health of adjacent second molars(M2s),the removal of N-M3s may be beneficial to the periodontal health of their neighbors.This study aimed to investigate the clinical,immunological,and microbiological changes of the periodontal condition around M2s following removal of neighboring N-M3s across a 6-month period.Subjects with at least one quadrant containing an intact first molar(M1),M2,and N-M3 were screened and those who met the inclusion criteria and decided to receive N-M3 extraction were recruited in the following investigation.M2 periodontal condition was interrogated before M3 extraction(baseline)and at 3 and 6 months postoperatively.Improvements in clinical periodontal indexes of M2s in response to their adjacent N-M3 removal,along with changes in inflammatory biomarkers among gingival crevicular fluid(GCF)and the composition of subgingival plaque collected from the distal sites of the M2s of the targeted quadrant were parallelly analyzed.Complete data of 26 tooth extraction patients across the follow-up period were successfully obtained and subsequently applied for statistical analysis.Compared to the baseline,the periodontal condition of M2s was significantly changed 6 months after N-M3 removal;specifically,the probing depth of M2s significantly reduced(P<0.001),the matrix metalloproteinase(MMP)-8 concentration involved in GCF significantly decreased(P=0.025),and the abundance of the pathogenic genera unidentified Prevotellaceae and Streptococcus significantly decreased(P<0.001 and P=0.009,respectively).We concluded that N-M3 removal was associated with superior clinical indexes,decreased GCF inflammatory biomarkers,and reduced pathogenic microbiome distribution within the subgingival plaque.Although the retention or removal of N-M3s continues to be controversial,our findings provide additional evidence that medical decisions should be made as early as possible or at least before the neighboring teeth are irretrievably damaged.展开更多
Surgical extraction of the third molar is the most commonly performed surgical procedure in the clinical practice of oral surgery.Third molar surgery is warranted when there is inadequate space for eruption,malpositio...Surgical extraction of the third molar is the most commonly performed surgical procedure in the clinical practice of oral surgery.Third molar surgery is warranted when there is inadequate space for eruption,malpositioning,or risk for cyst or odontogenic tumor formation.Preoperative assessment should include a detailed morphologic analysis of the third molar and its relationship to adjacent structures and surrounding tissues.Due to developments in medical engineering technology,computed tomography(CT)now plays a critical role in providing the clear images required for adequate assessment prior to third molar surgery.Removal of the maxillary third molar is associated with a risk for maxillary sinus perforation,whereas removal of the mandibular third molar can put patients at risk for a neurosensory deficit from damage to the lingual nerve or inferior alveolar nerve.Multiple factors,including demographic,anatomic,and treatment-related factors,influence the incidence of nerve injury during or following removal of the third molar.CT assessment of the third molar prior to surgery can identify some of these risk factors,such as the absence of cortication between themandibular third molar and the inferior alveolar canal,prior to surgery to reduce the risk for nerve damage.This topic highlight presents an overview of the clinical significance of CT assessment in third molar surgery.展开更多
This case report describes the diagnosis and endodontic therapy of maxillary fused second and third molars, using cone-beam computed tomography (CBCT). A 31-year-old Chinese male, with no contributory medical or fam...This case report describes the diagnosis and endodontic therapy of maxillary fused second and third molars, using cone-beam computed tomography (CBCT). A 31-year-old Chinese male, with no contributory medical or family/social history, presented with throbbing pain in the maxillary right molar area following an unsuccessful attempted tooth extraction. Clinical examination revealed what appeared initially to be a damaged large extra cusp on the buccal aspect of the distobuccal cusp of the second molar. However, CBCT revealed that a third molar was fused to the second molar. Unexpectedly, the maxillary left third molar also was fused to the second molar, and the crown of an unerupted supernumerary fourth molar was possibly also fused to the apical root region of the second molar. Operative procedures should not be attempted without adequate radiographic investigation. CBCT allowed the precise location of the root canals of the right maxillary fused molar teeth to permit successful endodontic therapy, confirmed after 6 months.展开更多
Aims & Objectives: This study was performed to evaluate the incidence, risk factors (age, sex, infection, radiographic difficulty of the extraction, tobacco use) contributing to the development of dry socket and c...Aims & Objectives: This study was performed to evaluate the incidence, risk factors (age, sex, infection, radiographic difficulty of the extraction, tobacco use) contributing to the development of dry socket and clinical features following surgical removal of impacted mandibular third molar. Materials and Methods: The study included 63 patients during period of September 2009 to September 2011 in the age group of 18 to 53 years with impacted mandibular third molars all of which were surgically removed under local anesthesia by the same operator. Following surgery all patients received a single dose of 4 mg corticosteroid intravenously and similar prescriptions for analgesics, antibiotics and postoperative instructions. All patients were reviewed at 3rd and 7th day postoperatively. Results: In this study incidence of dry socket was 6.3%. We also noticed onset of symptom mostly appeared within 48 hours. Postoperatively pain, bare bone and halitosis were the most significant clinical feature at 3rd postoperative day and pain, empty socket and bare bone were most significant clinical feature at 7th postoperative day. Variables like right 3rd molar impaction, patients mean age between 19 - 32 years, female, preoperative infection, radiographically difficult impaction and habitual tobacco users showed a higher incidence of dry socket formation. Conclusion: Incidence of dry socket formation is multifactorial and therefore, there is need to evaluate all factors, with special attentions in handling these patients to reduce the incidence of dry socket formation.展开更多
Extraction of the lower third molar is one of the most common procedures performed in oral surgery. In general, impacted tooth extraction involves sectioning the tooth’s crown and roots. In order to divide the impact...Extraction of the lower third molar is one of the most common procedures performed in oral surgery. In general, impacted tooth extraction involves sectioning the tooth’s crown and roots. In order to divide the impacted tooth so that it can be extracted, high-speed air turbine drills are frequently used. However, complications related to air turbine drills may occur. In this report, we propose an alternative tooth sectioning method that obviates the need for air turbine drill use by using a low-speed straight handpiece and carbide bur. A 21-year-old female patient presented to the institute’s dental hospital complaining of symptoms localized to the left lower third molar tooth that were suggestive of impaction. After physical examination, tooth extraction of the impacted left lower third molar was proposed and the patient consented to the procedure. The crown was divided using a conventional straight low-speed handpiece and carbide bur. This carbide bur can easily cut through the enamel of crown. On post-operative day number five, suture was removed and the wound was extremely clear. This technique could minimise intra-operative time and reduce the morbidity associated with air turbine drill assisted lower third molar extraction.展开更多
Aims and Objectives: The aim of the study was to compare the effect of complete and partial wound closures on postoperative sequelae and complications after surgical removal of impacted mandibular third molars. Patien...Aims and Objectives: The aim of the study was to compare the effect of complete and partial wound closures on postoperative sequelae and complications after surgical removal of impacted mandibular third molars. Patients and Methods: One hundred and twenty patients who required 121 surgical extractions of mandibular impacted third molars were included in the study. Patients were randomly divided into 2 groups based on wound closure after surgery. In group 1 (complete wound closure, n1 = 60) patients had their extraction sockets completely closed by mucosal flap while in group 2 (partial wound closure, n2 = 60) patients had their extraction sockets partially closed. Data collected included maximum inter-incisal distance (MID) and facial width which were recorded both preoperatively and postoperatively. What also recorded were postoperative pain intensity and postoperative complications. Results: There were 50 (41.7%) males and 70 (58.3%) females (male to female ratio of 1:1.4);age range was 18-40 years and the mean was 26 ± 10 years. The mean ages of patients in both groups showed no significant difference (group 1 = 26.5 ± 7.2;group 2 = 27.1 ± 8.1). The pain was maximal at the first postoperative day review and it gradually reduced in intensity towards the preoperative values for both groups. The pain perceptionsin patients in group 2 were however significantly lower than those of group 1 on days 1 and 3 but not statistically different on day 7. The mean difference in the postoperative and preoperative MID was greatest on the 1st postoperative day and gradually became smaller on the subsequent review days. Comparison of this mean difference between the 2 groups however showed a significant difference in the 2 groups only on day 7. Maximal swelling was noted in both groups on the third postoperative day. A comparison of the mean facial width between the two groups showed no statistically significant difference on all the review days. The postoperative complication rate was 5% in both groups. Conclusions: The results of the study indicate that there was a comparative reduction in postoperative sequelae namely pain and trismus after impacted mandibular third molar surgery when a partial wound closure technique was done. However, there was no significant difference in the postoperative complication rate between the two groups.展开更多
Background: The over-ambitious use of surgical drills for almost every case of third molar impaction is on the increase in most established oral surgery centers. The purpose of this study was to assess and compare the...Background: The over-ambitious use of surgical drills for almost every case of third molar impaction is on the increase in most established oral surgery centers. The purpose of this study was to assess and compare the severity of post operative symptoms of swelling and pain that accompany the use of surgical drill in the buccal guttering technique and the non application of drill in an alveolar expansion technique. Methods: Consecutive patients with bilateral impacted lower third molars not associated with pericoronitis were included in the study, a total of 10 patients were included in the study. Extraction of both impacted third molars was done consecutively on the same day under local anaesthesia. Post operative morbidities that were assessed clinically are swelling and pain. Results: A total of 10 patients, 70% were females and males were 30%. Age range was 27 - 35 yrs.Out of the eight patients that had the two different techniques, 7 preferred the use of the alveolar expansion technique in which drill was not used. There were statistically significant differences in swellings between these two techniques, (p 0.01). Conclusions: To avoid excessive swelling and pain from over-ambitious cut-ting of soft tissues and drilling of bone, alveolar expansion technique should be considered first in pa-tients with less dense bone.展开更多
Non-steroidal anti-inflammatory drugs like Ibupro- fen alleviate mild to moderate postoperative pain caused by the third molar extractions. Moreover, Acetaminophen is a non-opioid analgesic with anti-pyretic propertie...Non-steroidal anti-inflammatory drugs like Ibupro- fen alleviate mild to moderate postoperative pain caused by the third molar extractions. Moreover, Acetaminophen is a non-opioid analgesic with anti-pyretic properties, effective in relieving mild to moderate pain. On the other hand, recent studies have demonstrated that Caffeine also acts as an analgesic adjuvant when combined with Acetaminophen, Aspirin, or their mixture. The objective of study is to compare the efficacy of a combination of Ibuprofen 200 mg and Acetaminophen 325 mg plus Caffeine 40 mg with Ibuprofen 400 mg alone for relieving the pain after surgical removal of impacted mandibular third molar. 80 adult patients (56 females, 24 males) were randomly placed into two groups. Preoperative pain recorded prior to the surgery and compare with patients’ pain after the operation. According to findings, there was no significant relationship between preoperative and postoperative pain (P value > 0.05) and also between surgical trauma and postoperative pain (P value > 0.05). The mean pain showed a slight numerical superiority for the group which used Ibu-profen plus Acetaminophen plus Caffeine especially 3hours after surgery, but there was no significant difference between the two groups (P value = 0.073). In conclusion, combination of Ibuprofen plus aceta-minophen plus caffeine does not offer any clinical advantages compared with Ibuprofen for alleviating acute postoperative pain after third molar surgeries.展开更多
Osteoradionecrosis(ORN),a pathological condition characterized by a nonvital bone occurring in the site of radiation injury,is one of the significant risks following extraction of highly impacted third molar teeth in ...Osteoradionecrosis(ORN),a pathological condition characterized by a nonvital bone occurring in the site of radiation injury,is one of the significant risks following extraction of highly impacted third molar teeth in patients treated with head&neck radiotherapy for oral cancer.Therefore,the surgery’s meticulous planning is essential to avoid such complications.This case report describes a 63-year-old male patient diagnosed with an impacted lower third molar(tooth#38)with concurrent basal cell carcinoma of the right ear and squamous cell carcinoma of the right vocal cord treated with radiotherapy.Taking into account the patient’s health status,a minimally invasive osteotomy and a corono-radicular separation procedure were performed.This procedure allowed us to reduce the risk of mandibular ORN.Three years later,the healing was complete,and the situation was stable.展开更多
Aim & Objectives: The aim of this prospective pilot-study was to assess the efficacy of intra alveolar application of 1% chlorhexidine gel (CHX) on the reduction of dry socket (DS) occurrence following surgical ex...Aim & Objectives: The aim of this prospective pilot-study was to assess the efficacy of intra alveolar application of 1% chlorhexidine gel (CHX) on the reduction of dry socket (DS) occurrence following surgical extraction of mandibular third molars. Materials and Methods: A randomized split-mouth-design study included twenty-five patients with bilaterally impacted lower third molars (partial or full bone) requiring full thickness mucoperiastal flap reflection for extraction. Following surgical extraction of third lower molar, 2 ml of gel containing 1% chlorhexidine digluconate (Chlorhexamed? Gel 1%) were placed in the experimental side, and saline solution was used for irrigation in the control side of extraction sockets, both followed by suturing of extraction site. The surgeries and follow up examinations were performed by the same surgeon. The follow up visits were performed at 48 hours and on day seven, post surgery where presence or absence of dry socket using the Blum criteria for diagnosis was evaluated and pain intensity by Visual Analogue Scale (VAS) 0 - 100 was observed. Results: In this pilot study, dry socket was present in 4.0 and 28.0% of cases in the experimental and control groups, respectively (P = 0.048). Fisher’s test revealed a statistically significant reduction of dry socket occurrence following the use of 1% CHX gel versus saline solution. Conclusion: The application of CHX gel 1% may significantly reduce the incidence of DS following third molar extraction. Prophylactic use of CHX gel 1% may be suggested in all patients, especially in the patients at risk of development of DS.展开更多
文摘BACKGROUND Extraction of impacted third molars often leads to severe complications caused by damage to the inferior alveolar nerve(IAN).AIM To proposes a method for the partial grinding of an impacted mandibular third molar(IMM3)near the IAN to prevent IAN injury during IMM3 extraction.METHODS Between January 1996 and March 2022,25 patients with IMM3 roots near the IAN were enrolled.The first stage of the operation consisted of grinding a major part of the IMM3 crown with a high-speed turbine dental drill to achieve sufficient space between the mandibular second molar and IMM3.After 6 months,when the root tips were observed to be away from the IAN on X-ray examination,the remaining part of the IMM3 was completely removed.RESULTS All IMM3s were extracted easily without symptoms of IAN injury after extraction.CONCLUSION Partial IMM3 grinding may be a good alternative treatment option to avoid IAN injury in high-risk cases.
基金supported by the National Natural Science Foundation of China(U1904145)the Joint Funds for the Innovation of Science and Technology of Fujian province(2019Y9128).
文摘Background:This study aims to predict the extraction difficulty of mandibular third molars based on panoramic images using transfer learning while employing super-resolution(SR)technology to enhance the feasibility and validity of the prediction.Methods:We reviewed a total of 608 preoperative mandibular third molar panoramic radiographs from two medical facilities:the First Affiliated Hospital of Zhengzhou University(n=509;456 in the training set and 53 in the test set)and the Henan Provincial Dental Hospital(n=99 in the validation set).We conducted a deep-transfer learning network on high-resolution(HR)panoramic radiographs to improve the longitudinal resolution of the images and obtained the SR images.Subsequently,we constructed models named Model-HR and Model-SR using high-dimensional quantitative features extracted through the Least Absolute Shrinkage and Selection Operator method.The models’performances were evaluated using the receiver operating characteristic curve(ROC).To assess the reliability of the model,we compared the results from the test set with those of three dentists.Results:Model-SR outperformed Model-HR(area under the curve(AUC):0.779,sensitivity:85.5%,specificity:60.9%,and accuracy:79.8%vs.AUC:0.753,sensitivity:73.7%,specificity:73.9%,and accuracy:73.7%)in predicting the difficulty of extracting mandibular third molars.Both Model-HR(AUC=0.821,95%CI 0.687–0.956)and Model-SR(AUC=0.963,95%CI 0.921–0.999)demonstrated superior performance compared to expert dentists(highest AUC=0.799,95%CI 0.671–0.927).Conclusions:Model-SR yielded superior predictive performance in determining the difficulty of extracting mandibular third molars when compared with Model-HR and expert dentists’visual assessments.
文摘We present a case of a patient with rare anatomy of a maxillary second molar with three mesiobuccal root canals and a maxillary third molar with four separate roots, identified using multi-slice computed topography (CT) and three-dimensional reconstruction techniques. The described case enriched/might enrich our knowledge about possible anatomical aberrations of maxillary molars. In addition, we demonstrate the role of multi-slice CT as an objective tool for confirmatory diagnosis and successful endodontic management.
基金Supported by the People's Livelihood Science and Technology Program of Qingdao City(15-9-2-73-nsh)
文摘[Objectives] To shorten the time of removal of the bone embedded mandibular third molar,reduce the complications of tooth extraction,and explore a surgery method of resistance-free removal of the mandibular third molar. [Methods] A total of 50 patients with bone embedded mandibular third molar needing to be removed were selected. A 45° elevation turbine and a long tungsten steel drill were used to remove the mesial,buccal,and distal resistances. When necessary,tongue side and root resistance was removed,and the third molar was removed when there was basically no resistance around it. The removal time was recorded,followed up for 10 d,and the postoperative reaction was observed. [Results] The bone embedded mandibular third molars were removed for all patients within 15 min,and there was no serious postoperative reaction,all patients showed high satisfaction. [Conclusions]The method of resistance-free removal of the bone embedded mandibular third molar can significantly shorten the removal time,reduce the fear of patients,and ease pain of patients.
基金Supported by the Applied Basic Research Program of the 920th Hospital of the Joint Logistics Support Force,No.2019YGB15。
文摘BACKGROUND Morphological anomalies of teeth,including talon cusp,dens evaginatus,gemination,fusion,concrescence,root dilaceration,and taurodontism,always involve changes in the enamel,cementum and dentin.Diagnosing concrescent teeth through routine clinical examination alone is difficult,and most cases of concrescence are found accidentally during extraction.A definite preoperative diagnosis of concrescence would contribute to a better treatment plan and fewer undesirable complications CASE SUMMARY A 47-year-old woman who complained of left maxillary first molar loss for half a year presented to our department seeking treatment by dental implant restoration.Panoramic radiography and cone-beam computed tomography(CBCT)showed an unclear boundary between the distal root of the second molar and the mesial root of the third molar.The teeth were extracted under local anesthesia,and a definite diagnosis of concrescence was made by histopathological examination.CONCLUSION CBCT is a useful tool for diagnosing and planning the management of tooth concrescence and may be beneficial for reducing unnecessary complications.
文摘Double teeth refer to two teeth that are totally or partially joined by dentin and maybe their pulps. These developmental anomalies may be the result of either gemination or fusion. This is a case of a 15-year-old Indo-Trinidadian male who presented with the fusion of a mandibular third molar with a distomolar as an incidental finding. The patient had his general dental care provided by a paediatric dentist and was referred to an oral and maxillofacial radiologist, orthodontist, and oral surgeon for consultation. A Cone-beam CT was taken to supplement the plain film periapical and orthopantomogram radiographs. It showed the three-dimensional orientation of the double molar and the extent of joining. This is the first case of fusion of a mandibular third molar to a distomolar being reported in the Caribbean.
文摘Kissing molars (KMs) is a condition of occlusal molar surfaces in a single follicular space with roots extending in opposite directions. Here, we have reported a case of KMs in a 58-year-old woman. The patient complained of pain in the right mandibular molar region and was diagnosed with KMs consisting of the right mandibular second and third molars. Because of the patient’s pain having subsided at the time of the visit and her unwillingness to undergo tooth extraction, the patient was followed up. KMs is classified into three classes (I-III) and is either true-KMs or pseudo-KMs and presents with or without cystic variants of dental follicles. The presents as true-KMs class II without a cystic variant. With reference to the literature and based on our analysis, the mean age of patients affected by this specific case of KMs is 31.7 years and unilateral KMs is relatively more common (85.7%). Histopathological findings of dentigerous cysts are more often indicated (42.9%). The treatment policy for KMs should therefore be based on the classification of KMs. Importantly, the focus should be on preserving the first and second molars as much as possible. The treatment approach, such as the employment of surgical removal or orthodontics, should be determined by considering the associated factors such as the crowns, tissues, and age of the patient.
基金supported by Biological Anthropology Innovation Team Project of JZMU(Grant No.JYLJ201702)Liaoning Distinguished Professor Project(Grant No.LNTP20183501&LNTP201418701)。
文摘Teeth affect not only oral problems but also facial morphology.In China,there are few reports about the influence of the third molars on the craniofacial morphology of Han youths.Using in vivo imaging software,3D reconstruction of craniofacial CTs were performed on 32 Chinese Han youths without mandibular third molars and 25 Chinese Han youth with full mandibular third molars.The morphology of their mandible and mandibular tissue was measured to identify differences.Among the morphological characteristics of hard tissues,except for∠ANB,people with a full eruption of the mandibular third molars had statistically significantly larger angle indicators than people without the eruption of the third molars.The soft tissue indicators also showed statistically significant discrepancies in terms of morphological facial height,mouth to gnathion distance,lip height,and mouth breadth.The most influential index for mandibular third molars was length of symphysis,followed by the four indicators of soft tissue and mandible length and height.Morphology facial height,mouth to gnathion distance,lip height,and height of symphysis were moderately correlated.The experimental results show that among Han youth in North China,the third molar eruption has a widespread influence on mandibular morphology,especially in angle,length,and height indicators.It also has a certain influence on maxillofacial soft tissue morphology.These results can be applied to future clinical risk assessment of the wisdom teeth and forensic personal identification of the cranial and maxillofacial region.
文摘This paper reported a case of fusion between an impacted third molar and a supernumerary tooth, in which a surgical intervention was carried out, with the objective of removing the dental elements. The panoramic radiography was complemented by the Donovan's radiographic technique; but because of the proximity of the dental element to the mandibular ramus, it was not possible to have a final fusion diagnosis. Hence, the Cone-Beam Computed Tomography--which provides precise three- dimensional information--was used to determinate the fusion diagnosis and also to help in the surgical planning. In this case report we observed that the periapical, occlusal and panoramic were not able to show details which could only be examined through the cone-beam computed tomo- graphy.
文摘The role of third molars in the oral cavity has been extensively studied over the years. Literature includes numerous diagnostic and treatment alternatives regarding the third molars. However, an issue that has not been discussed at the same level is their involvement in orthodontic therapy. The aim of this study is to present a review of the contemporary literature regarding the most broadly discussed aspects of the multifactorial role of third molars in orthodontics and which are of general dental interest too.
基金supported by the Major Research Program of the National Natural Science Foundation of China(Beijing,Subproject No.81991503)the Changjiang Scholars Program of the Ministry of Education of the People’s Republic of China(2016).
文摘Considering the adverse effects of nonimpacted third molars(N-M3s)on the periodontal health of adjacent second molars(M2s),the removal of N-M3s may be beneficial to the periodontal health of their neighbors.This study aimed to investigate the clinical,immunological,and microbiological changes of the periodontal condition around M2s following removal of neighboring N-M3s across a 6-month period.Subjects with at least one quadrant containing an intact first molar(M1),M2,and N-M3 were screened and those who met the inclusion criteria and decided to receive N-M3 extraction were recruited in the following investigation.M2 periodontal condition was interrogated before M3 extraction(baseline)and at 3 and 6 months postoperatively.Improvements in clinical periodontal indexes of M2s in response to their adjacent N-M3 removal,along with changes in inflammatory biomarkers among gingival crevicular fluid(GCF)and the composition of subgingival plaque collected from the distal sites of the M2s of the targeted quadrant were parallelly analyzed.Complete data of 26 tooth extraction patients across the follow-up period were successfully obtained and subsequently applied for statistical analysis.Compared to the baseline,the periodontal condition of M2s was significantly changed 6 months after N-M3 removal;specifically,the probing depth of M2s significantly reduced(P<0.001),the matrix metalloproteinase(MMP)-8 concentration involved in GCF significantly decreased(P=0.025),and the abundance of the pathogenic genera unidentified Prevotellaceae and Streptococcus significantly decreased(P<0.001 and P=0.009,respectively).We concluded that N-M3 removal was associated with superior clinical indexes,decreased GCF inflammatory biomarkers,and reduced pathogenic microbiome distribution within the subgingival plaque.Although the retention or removal of N-M3s continues to be controversial,our findings provide additional evidence that medical decisions should be made as early as possible or at least before the neighboring teeth are irretrievably damaged.
文摘Surgical extraction of the third molar is the most commonly performed surgical procedure in the clinical practice of oral surgery.Third molar surgery is warranted when there is inadequate space for eruption,malpositioning,or risk for cyst or odontogenic tumor formation.Preoperative assessment should include a detailed morphologic analysis of the third molar and its relationship to adjacent structures and surrounding tissues.Due to developments in medical engineering technology,computed tomography(CT)now plays a critical role in providing the clear images required for adequate assessment prior to third molar surgery.Removal of the maxillary third molar is associated with a risk for maxillary sinus perforation,whereas removal of the mandibular third molar can put patients at risk for a neurosensory deficit from damage to the lingual nerve or inferior alveolar nerve.Multiple factors,including demographic,anatomic,and treatment-related factors,influence the incidence of nerve injury during or following removal of the third molar.CT assessment of the third molar prior to surgery can identify some of these risk factors,such as the absence of cortication between themandibular third molar and the inferior alveolar canal,prior to surgery to reduce the risk for nerve damage.This topic highlight presents an overview of the clinical significance of CT assessment in third molar surgery.
基金the financial support received from A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (2011-137)
文摘This case report describes the diagnosis and endodontic therapy of maxillary fused second and third molars, using cone-beam computed tomography (CBCT). A 31-year-old Chinese male, with no contributory medical or family/social history, presented with throbbing pain in the maxillary right molar area following an unsuccessful attempted tooth extraction. Clinical examination revealed what appeared initially to be a damaged large extra cusp on the buccal aspect of the distobuccal cusp of the second molar. However, CBCT revealed that a third molar was fused to the second molar. Unexpectedly, the maxillary left third molar also was fused to the second molar, and the crown of an unerupted supernumerary fourth molar was possibly also fused to the apical root region of the second molar. Operative procedures should not be attempted without adequate radiographic investigation. CBCT allowed the precise location of the root canals of the right maxillary fused molar teeth to permit successful endodontic therapy, confirmed after 6 months.
文摘Aims & Objectives: This study was performed to evaluate the incidence, risk factors (age, sex, infection, radiographic difficulty of the extraction, tobacco use) contributing to the development of dry socket and clinical features following surgical removal of impacted mandibular third molar. Materials and Methods: The study included 63 patients during period of September 2009 to September 2011 in the age group of 18 to 53 years with impacted mandibular third molars all of which were surgically removed under local anesthesia by the same operator. Following surgery all patients received a single dose of 4 mg corticosteroid intravenously and similar prescriptions for analgesics, antibiotics and postoperative instructions. All patients were reviewed at 3rd and 7th day postoperatively. Results: In this study incidence of dry socket was 6.3%. We also noticed onset of symptom mostly appeared within 48 hours. Postoperatively pain, bare bone and halitosis were the most significant clinical feature at 3rd postoperative day and pain, empty socket and bare bone were most significant clinical feature at 7th postoperative day. Variables like right 3rd molar impaction, patients mean age between 19 - 32 years, female, preoperative infection, radiographically difficult impaction and habitual tobacco users showed a higher incidence of dry socket formation. Conclusion: Incidence of dry socket formation is multifactorial and therefore, there is need to evaluate all factors, with special attentions in handling these patients to reduce the incidence of dry socket formation.
文摘Extraction of the lower third molar is one of the most common procedures performed in oral surgery. In general, impacted tooth extraction involves sectioning the tooth’s crown and roots. In order to divide the impacted tooth so that it can be extracted, high-speed air turbine drills are frequently used. However, complications related to air turbine drills may occur. In this report, we propose an alternative tooth sectioning method that obviates the need for air turbine drill use by using a low-speed straight handpiece and carbide bur. A 21-year-old female patient presented to the institute’s dental hospital complaining of symptoms localized to the left lower third molar tooth that were suggestive of impaction. After physical examination, tooth extraction of the impacted left lower third molar was proposed and the patient consented to the procedure. The crown was divided using a conventional straight low-speed handpiece and carbide bur. This carbide bur can easily cut through the enamel of crown. On post-operative day number five, suture was removed and the wound was extremely clear. This technique could minimise intra-operative time and reduce the morbidity associated with air turbine drill assisted lower third molar extraction.
文摘Aims and Objectives: The aim of the study was to compare the effect of complete and partial wound closures on postoperative sequelae and complications after surgical removal of impacted mandibular third molars. Patients and Methods: One hundred and twenty patients who required 121 surgical extractions of mandibular impacted third molars were included in the study. Patients were randomly divided into 2 groups based on wound closure after surgery. In group 1 (complete wound closure, n1 = 60) patients had their extraction sockets completely closed by mucosal flap while in group 2 (partial wound closure, n2 = 60) patients had their extraction sockets partially closed. Data collected included maximum inter-incisal distance (MID) and facial width which were recorded both preoperatively and postoperatively. What also recorded were postoperative pain intensity and postoperative complications. Results: There were 50 (41.7%) males and 70 (58.3%) females (male to female ratio of 1:1.4);age range was 18-40 years and the mean was 26 ± 10 years. The mean ages of patients in both groups showed no significant difference (group 1 = 26.5 ± 7.2;group 2 = 27.1 ± 8.1). The pain was maximal at the first postoperative day review and it gradually reduced in intensity towards the preoperative values for both groups. The pain perceptionsin patients in group 2 were however significantly lower than those of group 1 on days 1 and 3 but not statistically different on day 7. The mean difference in the postoperative and preoperative MID was greatest on the 1st postoperative day and gradually became smaller on the subsequent review days. Comparison of this mean difference between the 2 groups however showed a significant difference in the 2 groups only on day 7. Maximal swelling was noted in both groups on the third postoperative day. A comparison of the mean facial width between the two groups showed no statistically significant difference on all the review days. The postoperative complication rate was 5% in both groups. Conclusions: The results of the study indicate that there was a comparative reduction in postoperative sequelae namely pain and trismus after impacted mandibular third molar surgery when a partial wound closure technique was done. However, there was no significant difference in the postoperative complication rate between the two groups.
文摘Background: The over-ambitious use of surgical drills for almost every case of third molar impaction is on the increase in most established oral surgery centers. The purpose of this study was to assess and compare the severity of post operative symptoms of swelling and pain that accompany the use of surgical drill in the buccal guttering technique and the non application of drill in an alveolar expansion technique. Methods: Consecutive patients with bilateral impacted lower third molars not associated with pericoronitis were included in the study, a total of 10 patients were included in the study. Extraction of both impacted third molars was done consecutively on the same day under local anaesthesia. Post operative morbidities that were assessed clinically are swelling and pain. Results: A total of 10 patients, 70% were females and males were 30%. Age range was 27 - 35 yrs.Out of the eight patients that had the two different techniques, 7 preferred the use of the alveolar expansion technique in which drill was not used. There were statistically significant differences in swellings between these two techniques, (p 0.01). Conclusions: To avoid excessive swelling and pain from over-ambitious cut-ting of soft tissues and drilling of bone, alveolar expansion technique should be considered first in pa-tients with less dense bone.
文摘Non-steroidal anti-inflammatory drugs like Ibupro- fen alleviate mild to moderate postoperative pain caused by the third molar extractions. Moreover, Acetaminophen is a non-opioid analgesic with anti-pyretic properties, effective in relieving mild to moderate pain. On the other hand, recent studies have demonstrated that Caffeine also acts as an analgesic adjuvant when combined with Acetaminophen, Aspirin, or their mixture. The objective of study is to compare the efficacy of a combination of Ibuprofen 200 mg and Acetaminophen 325 mg plus Caffeine 40 mg with Ibuprofen 400 mg alone for relieving the pain after surgical removal of impacted mandibular third molar. 80 adult patients (56 females, 24 males) were randomly placed into two groups. Preoperative pain recorded prior to the surgery and compare with patients’ pain after the operation. According to findings, there was no significant relationship between preoperative and postoperative pain (P value > 0.05) and also between surgical trauma and postoperative pain (P value > 0.05). The mean pain showed a slight numerical superiority for the group which used Ibu-profen plus Acetaminophen plus Caffeine especially 3hours after surgery, but there was no significant difference between the two groups (P value = 0.073). In conclusion, combination of Ibuprofen plus aceta-minophen plus caffeine does not offer any clinical advantages compared with Ibuprofen for alleviating acute postoperative pain after third molar surgeries.
文摘Osteoradionecrosis(ORN),a pathological condition characterized by a nonvital bone occurring in the site of radiation injury,is one of the significant risks following extraction of highly impacted third molar teeth in patients treated with head&neck radiotherapy for oral cancer.Therefore,the surgery’s meticulous planning is essential to avoid such complications.This case report describes a 63-year-old male patient diagnosed with an impacted lower third molar(tooth#38)with concurrent basal cell carcinoma of the right ear and squamous cell carcinoma of the right vocal cord treated with radiotherapy.Taking into account the patient’s health status,a minimally invasive osteotomy and a corono-radicular separation procedure were performed.This procedure allowed us to reduce the risk of mandibular ORN.Three years later,the healing was complete,and the situation was stable.
文摘Aim & Objectives: The aim of this prospective pilot-study was to assess the efficacy of intra alveolar application of 1% chlorhexidine gel (CHX) on the reduction of dry socket (DS) occurrence following surgical extraction of mandibular third molars. Materials and Methods: A randomized split-mouth-design study included twenty-five patients with bilaterally impacted lower third molars (partial or full bone) requiring full thickness mucoperiastal flap reflection for extraction. Following surgical extraction of third lower molar, 2 ml of gel containing 1% chlorhexidine digluconate (Chlorhexamed? Gel 1%) were placed in the experimental side, and saline solution was used for irrigation in the control side of extraction sockets, both followed by suturing of extraction site. The surgeries and follow up examinations were performed by the same surgeon. The follow up visits were performed at 48 hours and on day seven, post surgery where presence or absence of dry socket using the Blum criteria for diagnosis was evaluated and pain intensity by Visual Analogue Scale (VAS) 0 - 100 was observed. Results: In this pilot study, dry socket was present in 4.0 and 28.0% of cases in the experimental and control groups, respectively (P = 0.048). Fisher’s test revealed a statistically significant reduction of dry socket occurrence following the use of 1% CHX gel versus saline solution. Conclusion: The application of CHX gel 1% may significantly reduce the incidence of DS following third molar extraction. Prophylactic use of CHX gel 1% may be suggested in all patients, especially in the patients at risk of development of DS.