Residual enamel removal to improve outcomes of mandibular third molar coronectomy: A single-center retrospective cohort study.

This study aimed to analyze post-coronectomy complications, chronological root survival rate (success rate) using Kaplan-Meier analysis, and postoperative radiographic signs for root extraction. A total of 555 mandibular third molar coronectomies were clinically and radiologically evaluated (mean follow-up period, 27.2 months; range, 1 month to 10.5 years). Complications were observed in 22 (4.0%) cases. Temporary inferior alveolar nerve damage was observed in one (0.2%) case, and 21 (3.8%) retained roots required extraction between 1 and 64 months after coronectomy due to dry socket (two cases, 0.4%), primary non-wound closure (10 cases, 1.8%), secondary root exposure (seven cases, 1.3%), and submucosal root eruption (two cases, 0.4%). Residual enamel after coronectomy was more significantly found on 13 (61.9%) of 21 extracted roots than on 30 (5.6%) of 534 surviving roots. Kaplan-Meier analysis revealed an overall survival rate of 93.8% at 5 years and 92.2% at 10 years. The 5-year survival rates differed significantly (p < 0.001) between the enamel-free (97.0%) and residual enamel-attached (58.3%) roots. The Cox proportional hazards model showed a hazard ratio of 20.87 (95% confidence interval, 8.58-50.72). The long-term outcomes of coronectomy were satisfactory, and a higher success rate is expected when the enamel is completely removed during coronectomy.

Effect of mineralized dentin matrix on the prognosis of bone defect and retained root after coronectomy.

OBJECTIVE: To investigate the impact of mineralized dentin matrix (MDM) on the prognosis on bone regeneration and migration of retained roots after coronectomy. MATERIALS AND METHODS: Patients were divided into three groups based on the type of bone graft after coronectomy: Group C (n = 20, collagen), Group T (n = 20, tricalcium phosphate (TCP) + collagen), and Group D (n = 20, MDM + collagen). CBCT scans, conducted immediately and 6 months after surgery, were analyzed using digital software. Primary outcomes, including changes in bone defect depth and retained root migration distance, were evaluated 6 months after surgery. RESULTS: After 6 months, both Groups D and T exhibited greater reduction of the bone defect and lesser retained root migration than Group C (p < 0.001). Group D had greater regenerated bone volume in the distal 2 mm (73 mm3 vs. 57 mm3, p = 0.011) and lesser root migration (2.18 mm vs. 2.96 mm, p < 0.001) than Group T. The proportion of completely bone embedded retained roots was also greater in Group D than in Group C (70.0% vs. 42.1%, p = 0.003). CONCLUSIONS: MDM is an appropriate graft material for improving bone defect healing and reducing retained root migration after coronectomy. CLINICAL RELEVANCE: MDM is an autogenous material prepared chairside, which can significantly improve bone healing and reduce the risk of retained root re-eruption. MDM holds promise as a routine bone substitute material after M3M coronectomy.

Coronectomia como técnica alternativa à exodontia de terceiros molares impactados com risco de lesão ao nervo alveolar inferior / Coronectomy as an alternative technique to the extraction of impacted third molars with risk of injury to the inferior alveolar nerve

A coronectomia consiste no procedimento em que se faz a remoção da coroa do dente deixando a raiz in situ. Tal técnica é indicada para dentes posteriores impactados que apresentem proximidade com o canal mandibular representando assim um risco ao nervo mandibular caso seja feita uma exodontia. O seguinte trabalho tem como objetivo demonstrar os aspectos positivos relacionados ao emprego da técnica de coronectomia para dentes posteriores impactados. Foram realizadas buscas bibliográficas nas bases de dados PUBMED, MEDLINE e sciELO usando os descritores "coronectomia", "coronectomy", "terceiros molares impactados", "trigeminal", "nerve damage", respeitando critérios de relevância quanto ao tema foram selecionados 31 artigos. Sabe-se que pelo canal mandibular passa o nervo alveolar inferior e esse é responsável pela inervação sensitiva de estruturas anatômicas importantes, logo dentes impactados que tenham grande proximidade com o canal mandibular quando empregadas técnicas de exodontia correm o risco de lesionar o nervo podendo gerar perda da sensibilidade de forma passageira ou permanente, a indicação para realização da técnica precisa ser feita posteriormente à análise radiográfica e tomográfica da relação do dente com o canal mandibular. A técnica consiste na remoção da coroa do dente e o suficiente da raiz abaixo da crista vestibular e lingual do osso, para que esse possa desencadear um processo de cicatrização natural sobre as raízes retidas. Conclui-se que a coronectomia é um procedimento alternativo seguro e eficaz para casos específicos que se tem indicação e apresenta prognóstico favorável.

The coronectomy consists of the procedure in which the crown of the tooth is removed leaving the root in situ. This technique is indicated for impacted posterior teeth in close proximity to the mandibular canal representing a risk to the mandibular nerve if an extraction is performed. The following study has the porpouse to demonstrate the positive aspects related to the use of the coronectomy technique for impacted posterior teeth. Bibliographic searches were carried out in the databases PUBMED, MEDLINE, sciELO, using the DeCS "coronectomy", "odontectomy", "trigeminal", "nerve damage", respecting the criterion of relevance to the topic, 31 articles were selected. It is known that the inferior alveolar nerve passes through the mandibular canal and is responsible for the sensitive innervation of important anatomical structures, so impacted teeth that are very close to the mandibular canal when extraction techniques are used has the risk of injuring the nerve, which may lead to temporary or permanent loss of sensitivity, the indication for performing the technique needs to be made after the radiographic and tomographic analysis of the affinity between the tooth and the mandibular canal. The technique consists of removing the crown of the tooth and enough of the root below the buccal and lingual crest of the bone, so that it can trigger a natural healing process on the retained roots. It is concluded that coronectomy is a safe and effective alternative procedure for specific cases that are indicated and have a favorable prognosis.

The success rates and outcomes of mandibular third molar coronectomy: 167 cases.

PURPOSE: The purpose of this study was to assess success rates and to report complications of coronectomy of mandibular third molars (M3M), including intra-operative failure, pain, infection, dry socket, inferior dental alveolar (IAN) and lingual nerve (LN) injuries and re-operation rates. METHODS: Retrospective analysis of 167 coronectomies completed between January 2017 to December 2022 was undertaken. RESULTS: The success of coronectomy was 93%. Intra-operative failure was reported to be 3.6% (n = 8). Complications accounted for pain (15%, n = 24), infection (9%, n = 15) and dry socket (3.6%, n = 6). Three patients required removal of M3M root at 3 months (n = 2) and 24 months (n = 1), accounting for 1.8% re-operation rate. A total of number of patients who suffered a nerve injury was 12; three of these were permanent (LN - 1.2%, n = 2; IAN - 0.6%, n = 1), nine were temporary (IAN - 1.2%; n = 2, LN - 2.4%; n = 4; site not specified - 1.8%, n = 3). No patients with intra-operative failure and re-operation suffered IAN or LN injury post-operatively. CONCLUSION: Coronectomy offers a successful strategy for management of high risk M3M. The treatment outcomes can be improved with careful case selection and adjusting surgical technique, including assessment of root morphology, incomplete crown sectioning technique and avoidance of lingual retraction. Reporting of coronectomy success as a factor of surgical outcome, presence or absence of permanent IAN injury, persistent symptoms or any other long-standing complications (such as LN injury), and the need for re-operation accounting for root migration status may be a useful tool to measure coronectomy outcomes.

Association of indications for mandibular third molar coronectomy and the Pell and Gregory and the Winter classification systems.

PURPOSE: The purpose of this study was to determine how the surgeon's decision to perform a mandibular third molar coronectomy or surgical removal is associated with the impaction pattern as classified using Pell and Gregory or Winter's system. METHODS: This observational, cross-sectional study was conducted on 813 mandibular third molars belonging to 565 patients. All patients were referred for removal of the mandibular third molar and had radiographic signs indicating a close relationship with the inferior alveolar nerve. Panoramic images were classified according to the impaction pattern. RESULTS: A coronectomy was performed on 492 (60.5%) mandibular third molars. Most impacted mandibular third molars were class IIB with a mesioangular inclination. A significant association was found between the Pell and Gregory classification and the surgeon's choice (p = 0.002). Winter's classification was not significantly associated with surgeon choice (p = 0.425). CONCLUSION: Mandibular third molar coronectomy is chosen more frequently than surgical removal if molars are class III and position B. TRIAL REGISTRATION NUMBER: Not applicable.

Outcomes of Coronectomy and Total Odontectomy of Impacted Mandibular Third Molars.

OBJECTIVE: The aim of this research was to evaluate the surgical complications and neurosensory deficits after coronectomy and the complete removal of mandibular third molars. METHODS: The study sample included patients requiring surgical removal of mandibular third molars. A coronectomy was conducted on 220 teeth showing signs of close proximity to the inferior alveolar canal. A complete extraction was performed on 218 teeth with no risk signs. The patients were evaluated at 1 week and 1, 3, 6, 12, and 24 months after surgery for pain, swelling, neurologic deficit, dry socket, postoperative bleeding, infection, root migration, and eruption. RESULTS: No significant difference was noted in pain and swelling; however, bleeding and dry socket were significantly higher in the odontectomy group (P = .017). The inferior alveolar nerve deficit was higher in the odontectomy group (3.7%) than the coronectomy group (0.5%) (P = .017). The percentage and distance of root migration of coronectomised teeth at 3, 6, and 12 months were 60% (2.37 ± 0.96 mm), 66% (3.35 ± 0.86 mm), and 74% (3.85 ± 0.93 mm), respectively. CONCLUSIONS: Coronectomy is a safe procedure and should be performed when the roots are closely associated with the mandibular canal. Although root migration is common, the likelihood of root exposure is low and roots rarely need removal.

[Microanatomy features in third molars roots adjacent to mandibular canal]. / Osobennosti anatomii kornei tret'ikh molyarov i nizhnechelyustnogo kanala pri ikh tesnom prileganii.

THE PURPOSE: Of the study is to reduce the risk of postoperative neuropathy of the inferior alveolar nerve by improving diagnostic methods, assessment of individual topographic and anatomical features and extraction technique of impacted teeth adjacent to the mandibular canal. MATERIALS AND METHODS: According to the CBCT examination, orthopantomography and macroscopic examination of removed third molars roots (n=140) the relative position of the mandibular canal and the roots of the third molars were studied. RESULTS: Three variants of close mandibular canal and third molars position have been identified. In the lateral and apical nerve position, the root surface depressions were detected. With inter-radicular position fit, the mandibular canal and the nerve bundle form a «bed¼ in between impacted tooth roots. CONCLUSION: The injury of neurovascular bundle prognosis during extraction with an interadicular mandibular position depends on roots anatomy and their convergence degree. If the interradicular distance is less than the diameter of the mandibular canal, nerve injury during tooth extraction is inevitable, in such cases coronectomy is indicated.

Accuracy of computer-assisted dynamic navigation when performing coronectomy of the mandibular third molar: A pilot study.

OBJECTIVES: The study represents a preliminary evaluation of the accuracy of the dynamic navigation system (DNS) in coronectomy of the mandibular third molar (M3M). METHODS: The study included participants with an impacted M3M near the inferior alveolar canal. The coronectomy planes were designed before the surgery using cone-beam computed tomography (CBCT) imaging data and then loaded into the DNS program. Intraoperatively, the navigation system was used to guide the complete removal of the target crown. Postoperative CBCT imaging was used to assess any three-dimensional deviations of the actual postoperative from the planned preoperative section planes for each patient. RESULTS: A total of 12 patients (13 teeth) were included. The root mean square (RMS) deviation of the preoperatively designed plane from the actual postoperative surface was 0.69 ± 0.21 mm, with a maximum of 1.45 ± 0.83/-1.87 ± 0.63 mm deviation. The areas with distance deviations < 1 mm, 1-2 mm, and 2-3 mm were 71.97 ± 5.72 %, 22.96 ± 6.57 %, and 4.52 ± 2.28 %, respectively. Most patients showed extremely high convexity of the surface area located in the mesial region adjacent to the base of the extraction socket. There was no observable evidence of scratching of the buccolingual bone plate at the base of the extraction socket by the handpiece drill. CONCLUSIONS: These results provide preliminary support for the use of DNS-based techniques when extracting M3M using a buccal approach. This would improve the accuracy of coronectomy and reduce the potiential damage to the surrounding tissue. CLINICAL SIGNIFICANCE: DNS is effective for guiding coronectomy.

The effect of individual drilling sleeves on the precision of coronectomy tooth sections. An in vitro 3D-printed jaw model experiment.

OBJECTIVES: The aim of this in vitro study was to evaluate the effect of a 3D-printed drill sleeve (DS) on the precision and duration of coronectomy sections. MATERIALS AND METHODS: Thirty-six trainees and oral surgeons performed 72 coronectomy cuts in a 3D-printed, entirely symmetric mandible model. Coronectomy was performed freehand (FH) on one side and with a DS on the other side. The occurrence of "too superficial" (≥ 4 mm unprepared lingual tooth tissue) and "too deep" (drilling ≥ 1 mm deeper as tooth contour) cuts and sectioning times were registered. RESULTS: In 7 cases, the sections were "too deep" with FH, while none with DS (OR: 18.56; 95%CI: 1.02-338.5; p = 0.048). The deviation between virtually planned and real cut depths was significantly greater in the FH group (1.91 ± 1.62 mm) than in DS group (1.21 ± 0.72 mm) (p < 0.001). A total of 18 "too superficial" buccolingual sections occurred with FH, while 8 cases with DS (OR: 3.50; 95%CI: 1.26-9.72; p = 0.016). Suboptimal sections did not correlate with experience (p = 0.983; p = 0.697). Shortest, suboptimal drillings were most frequently seen distolingually (OR: 6.76; 95% CI: 1.57-29.07; p = 0.01). In the inexperienced group, sectioning time was significantly longer with FH (158.95 ± 125.61 s vs. 106.92 ± 100.79 s; p = 0.038). CONCLUSIONS: The DS effectively reduced tooth sectioning times by less experienced colleagues. Independently from the level of experience, the use of DS obviated the need for any preparation outside the lingual tooth contour and significantly decreased the occurrence of "too superficial" cuts, leaving thinner unprepared residual tooth tissue lingually. CLINICAL RELEVANCE: Coronectomy sections may result in lingual hard and soft tissue injury with the possibility of damaging the lingual nerve. The precision of the buccolingual depth-control can be improved, while surgical time can be reduced when applying a drilling sleeve.

Extraction of impacted mandibular third molars in close proximity to the inferior alveolar canal with coronectomy-miniscrew traction to avoid nerve injury.

OBJECTIVES: Extraction of impacted mandibular third molars (IMTMs) is the most common surgery performed in the Department of Oral and Maxillofacial Surgery. Inferior alveolar nerve (IAN) injury is a rare but severe complication, and the risk is significantly higher in cases of IMTM near the inferior alveolar canal (IAC). The existing surgical method to extract such IMTMs is either not safe enough or is time-consuming. A better surgical design is needed. MATERIALS AND METHODS: From August 2019 to June 2022, 23 patients underwent IMTM extraction by Dr. Zhao at Nanjing Stomatological Hospital, Affiliated Hospital of Medical School, Nanjing University, and were found to have IMTMs in close proximity to the IAC. Due to high IAN injury risk, these patients underwent coronectomy-miniscrew traction to extract their IMTMs. RESULTS: The time between coronectomy-miniscrew insertion and complete removal of the IMTM was 32.65 ± 2.110 days, which was significantly shorter than that of traditional orthodontic traction. Two-point discrimination testing revealed no IAN injury, and no injury was reported by patients during follow-up. Other complications, such as severe swelling, severe bleeding, dry socket, and limited mouth opening, were not observed. Postoperative pain levels were not significantly higher in the coronectomy-miniscrew traction group than in the traditional IMTM extraction group. CLINICAL RELEVANCE: For IMTMs that are in close proximity to the IAC and must be extracted, coronectomy-miniscrew traction is a novel approach to minimize the risk of IAN injury in a less time-consuming way with a lower possibility of complications.

Neurosensory Deficits of Inferior Alveolar Nerve Following Impacted Mandibular Third Molar Extraction: Comparison of One-Stage Complete Extraction with Two-Stage Partial Coronectomy Surgical Technique.

Objectives: Inferior alveolar nerve neurosensory deficit is a worrisome complication of surgical extraction of impacted mandibular third molars. A novel approach using two-stage partial coronectomy has been proposed as an alternative surgical procedure to reduce this complication. This study compared neurosensory deficits of inferior alveolar nerve following impacted mandibular third molar extraction using one-stage complete extraction with the two-stage partial coronectomy technique. Material and Methods: Subjects with mesioangular or horizontal impacted mandibular third molar with an intimate relationship with inferior dental canal who met the inclusion criteria were recruited for the study. Subjects were divided into one-stage and two-stage partial coronectomy techniques. The subjects were evaluated for the presence of inferior alveolar neurosensory deficit, and the relationships of neurosensory nerve deficit with sex, age and type of impaction. Results: Neurosensory deficit was observed in 5 subjects (7.8%), with all cases seen in the one-stage group. This difference was statistically significant (p = 0.03). The relationship between the incidence of neurosensory deficit and age, sex, type of impaction, surgical difficulty, operating time and root morphology was not statistically significant (p > 0.05). Conclusion: Findings from this study suggest partial coronectomy compared to one-stage complete extraction reduces the incidence of Inferior alveolar nerve neurosensory deficit.

Early root migration after a mandibular third molar coronectomy.

PURPOSE: This prospective cohort study aimed to assess early root migration after a coronectomy of the mandibular third molar at 2 and 6 months after surgery. METHODS: We included all patients treated with a coronectomy of an impacted mandibular third molar. The primary outcome measure was the extent of postoperative root migration after 2 and 6 months. Migration was measured as the distance between the root complex and a fixed point on the inferior alveolar canal. The secondary aim was to identify factors (age, impaction pattern, and patient sex) that affected the extent of root migration. RESULTS: One hundred and sixty-five coronectomies were performed in 141 patients (96 females and 45 males; mean age 33.1 years, SD 16.0). The 2-month checkup was completed by 121 patients that received 141 coronectomies. The 6-month check-up was completed by 73 patients that received 80 coronectomies. The mean root migrations were 3.30 mm (SD 2.53 mm) at 2 months and 5.27 mm (SD 3.14 mm) at 6 months. In the 2-6-month interval, the mean root migration was 2.58 mm (SD 2.07 mm). The extents of migration were similar during the 0-2-month interval and the 2-6-month interval (p = 0.529). Younger age was associated with greater root migration, and females experienced significantly greater migrations than males (p = 0.002). CONCLUSION: Roots migrated more rapidly in the first two postoperative months, compared to the 2-6-month interval. Age was negatively correlated with the extent of root migration, and females showed significantly greater migrations than males.

Straight lift technique as an alternative to surgical extraction of an intact, partially impacted mesioangular mandibular third molar.

Impacted mandibular third molar removal is the most common procedure performed by oral and maxillofacial surgeons. An array of alternative procedures have been suggested, like operculectomy in cases of pericoronitis and coronectomy in certain cases. However, these procedures pose several disadvantages, and we propose a relatively non-invasive 'straight lift technique'. This technique is specifically useful in straightening abnormally positioned mesioangular third molars as a substitute of complete removal. This can improve tooth function, eliminate the need for surgical intervention, and reduce the risk of complications associated with third molar removal.

Knowledge and Attitude Among the Saudi Dentists Towards Coronectomy of Impacted Mandibular Third Molars.

Purpose: Compared to the complete extraction of impacted third molars that are in close proximity to the mandibular canal, the coronectomy procedure is used as an alternative, owing to its minimal risk of damaging the Inferior alveolar nerve. Despite clear coronectomy concepts mentioned in the literature, the procedure is debatable. This study aimed to assess the knowledge and attitude towards the coronectomy procedure among dentists in Saudi Arabia. Patients and Methods: The 16 close-ended questionnaire was distributed electronically to 377 dentists over the country. It included the demographic data and the options given to their patients with complicated impacted third molars, and the number of coronectomy they have performed. The retrieved data were exported and transferred to the SPSS software program for analysis. The Chi-squared and Fisher's exact tests were used as appropriate for comparisons. A P-value <0.05 was considered significant. Results: Only 54 (15%) participants performed coronectomy procedure, and only 28.3% of the participants advised their patients to do coronectomy. Nearly two-thirds of the participants (71.9%) were aware of coronectomy procedures, with no significant differences (P> 0.05) between the groups. About 68.9% of the participants agreed that coronectomy aims to protect inferior alveolar nerve damage. More than 60% of participants believed that coronectomy is a reliable technique, while 40.6% of participants claimed that they were capable of deciding whether to do coronectomy or extraction. No significant differences were found between the groups concerning most of the study variables (P> 0.05). Conclusion: Knowledge of Saudi dentists towards coronectomy is good, while their attitude is still low. More learning strategies about coronectomy should be implemented.

Coronectomy of mandibular wisdom teeth: A case series.

INTRODUCTION AND IMPORTANCE: Coronectomy represents a common procedure performed in oral surgery, mostly involving the lower wisdom teeth when the extraction presents a risk of injury to the inferior alveolar nerve (NAI). The surgical approach can be described as a coronal separation of the tooth and leaving the roots intact in the socket. The result is impressive with the disappearance of the symptomatology at first and especially the root migration, which occurs most frequently in the first 6 months. CASES SERIES PRESENTATION: We present a series of clinical cases of coronectomy involving the lower wisdom tooth which was performed by respecting the preoperative, perioperative, and postoperative measures and whose indications were established correctly. DISCUSSION AND CONCLUSION: Besides the previously mentioned indication, this procedure can be associated with other clinical situations such as dentigerous cysts. However, there are several circumstances in which coronectomy is contraindicated. According to our study, we can conclude that coronectomy of mandibular wisdom teeth represents a reassuring alternative to the preservation of NAI. Complications may occur but follow-up remains a key point in visualizing the progression of the roots away from the mandibular canal.

Current thinking in lower third molar surgery.

The removal of lower third molar teeth is one of the most common surgical procedures performed worldwide, but many concepts in this surgery have been unclear and have engendered different opinions. This paper aims to review current thinking in certain pertinent aspects of this surgery to update the reader on the most current research and synthesise it to make clinical recommendations. Topics covered include preoperative imaging, timing of removal, flap design, lingual retraction, coronectomy, lingual split, closure techniques, and use of antibiotics, steroids, and drains.

Does the Coronectomy a Feasible and Safe Procedure to Avoid the Inferior Alveolar Nerve Injury during Third Molars Extractions? A Systematic Review.

This systematic review aimed to review the literature on the coronectomy technique and evaluate the incidence of success and complications as a surgical approach for inferior third molars. Online databases were searched for data on the frequency of inferior alveolar nerve damage, lingual nerve damage, root migration, pain, infection, dry socket, and extraction of the remaining root, and data on the necessity of reintervention were also extracted. Randomized clinical trials, controlled clinical trials, prospective cohort studies, and prospective and retrospective studies with or without the control group were intercepted. This systematic review was registered in PROSPERO (CDR 42020135485). Sixteen papers analyzed 2176 coronectomies in total, and only five of them were judged as appropriate according to methodological quality assessment. The incidence of inferior alveolar nerve injury was documented in 0.59% of the procedures, lingual nerve injury in 0.22%, infection 3.95%, dry socket 1.12%, extraction of the root 5.28%, and reintervention 1.13%. The pain was the most reported, in 22.04% of the population. This study provides an overview of the clinical success and complications of coronectomy, and their prevalence. A coronectomy may be considered a low-risk procedure and an option for treatment to avoid potential damage to nervous structures. However, patients should still undergo a full screening and evaluation of postsurgical procedures.

Coronectomy of mandibular third molars: a systematic literature review and case studies.

BACKGROUND: Extraction of mandibular third molars (M3M) close to the inferior alveolar nerve (IAN) has a higher risk of neurological disturbance. This review aims to evaluate the evidence supporting the use of the coronectomy technique compared to complete extraction for such M3Ms. Case studies by a specialist oral and maxillofacial surgeon are included to illustrate clinical practice. METHODS: Three databases (Cochrane Library, Embase, PubMed) were searched (November 2020). Additional articles were sought by hand searching the reference list of included articles. All studies published in English comparing outcomes of coronectomy with complete extraction with at least 50 subjects and 6 months follow-up were included. RESULTS: Of the six included studies, five reported a lower rate of IAN disturbance after coronectomy compared with complete extraction. There were no reported cases of lingual nerve disturbance. Other outcomes of coronectomy such as pain, infection, alveolar osteitis were either similar or lower compared to complete extraction. There were high rates of root migration but low rates of exposure and reoperation. Follow-up protocols varied considerably. CONCLUSIONS: There is medium quality evidence to support the option of coronectomy for high risk M3M cases. Further studies to develop follow-up protocols to assist general dental practice is warranted.

Three-dimensional assessment of root migration and rotation patterns after coronectomy: bone-embedded roots versus soft tissue-covered roots.

In this study, a three-dimensional evaluation was performed to explore differences between bone-embedded and soft tissue-covered roots after mandibular third molar (M3M) coronectomy. Patients were recruited according to the results of cone-beam computed tomography, 6 months after coronectomy. Completely bone-embedded M3Ms were assigned to group B, while completely soft tissue-covered M3Ms were assigned to group S. Data were recorded using digital software. A total of 213 M3Ms in 181 patients were investigated, of which 170 were assigned to the two study groups. Age was the primary factor influencing root migration (P<0.001). The smaller the degree of angulation of the M3M, the more likely was the root complex to rotate distally (r=-0.37, P<0.001). The depth of the impacted M3M contributed to the regeneration of new bone (P≤0.008). The length of the root complex (odds ratio 0.82, P=0.048) and distance from the root to the alveolar crest (odds ratio 1.23, P=0.026) were two critical factors influencing whether the root complex was bone-embedded. Ensuring that the length of the root complex is <7.6mm and the distance between the root and alveolar crest is ≥5mm were both found to be critical to the remaining root being completely bone-embedded and thus preventing eruption and the need for secondary surgery.

Coronectomy of Mandibular Third Molar: Four Years of Follow-Up of 130 Cases.

Inferior wisdom teeth extraction surgery may have some complications that, in some cases, could be prevented by a correct diagnosis and minimal surgery. Coronectomy is a technique used for wisdom teeth surgery where only the crown is extracted and the root/roots are left in situ. This procedure may be controversial, but it could limit the common risks of the extraction procedure. Nowadays, the indication and contraindication of this technique are debated, and clinicians normally extract the entire tooth. The following case series includes the data and follow-up radiographs of 130 patients who received a coronectomy, reporting the safety of the procedure. After a mean follow-up period of four years, no complications occurred. A total of 13 patients showed mobile roots but had no complications or symptoms. The roots migrated in a mesial or coronal direction in 31 patients; in 4 cases, they were removed because of patient preference. Coronectomy is a useful oral surgical procedure in certain complicated cases of mandibular wisdom tooth extraction.