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.

Combined orthodontic, surgical, and restorative approach to treat a complicated crown-root fracture in a maxillary central incisor.

This case report shows the treatment of a severe traumatic tooth injury. For the maxillary right central incisor, the trauma was considered a complicated crown-root fracture. The level of the fracture line, the length of the remaining root segment, and the presence and condition of the tooth fragment determined the type of therapy. Traumatized teeth with fractures below the alveolar crest are often considered hopeless. As this report shows, the treatment of a complicated crown-root fracture in the esthetic region can be challenging. Orthodontic extrusion and crown-length surgery were performed to bring the fracture line above the alveolar bone crest. A multidisciplinary approach was required for complete rehabilitation of the traumatized maxillary incisor. Suggestions are made to improve treatment planning of complicated crown-root fractures.

Concomitant Third Molar Removal During Sagittal Split Osteotomy of the Mandible.

It is described in textbook about management of third molar in orthognathic surgery that "ideally, the third molars should be removed 9 to 12 months before sagittal split osteotomy (SSO)." At the Chang Gung Craniofacial Center, the authors always remove mandibular third molars during SSO, because: removal of third molars at the same time of SSO could reduce psychological stress on patients by saving 1 surgical procedure under local anesthesia, better exposure of impacted third molars could be facilitated by sagittal split of buccal cortical plate, rigid fixation could be performed without difficulty by our fixation method using plates and screws crossover anterior oblique line. Strong force during the elevation of third molars, however, may result in the fracture of distal segment of SSO, where the buccal cortical plate is relatively thin because of the presence of third molar. Therefore, more care needs to be taken in the surgical technique, which is different from ordinary tooth extraction. In this paper, the details of surgical procedure of third molar removal during SSO were reported.

Preventive treatment of post-traumatic dental infraocclusion: study on the knowledge of dental decoronation in a sample of Italian dental students and dentists.

AIM: The aim of the present work is to investigate whether dental decoronation is a procedure known by a sample of dental students and Italian dentists. Dental decoronation technique is performed in order to mitigate the outcomes which may occur after a delayed tooth replantation. MATERIALS AND METHODS: A cognitive survey about the knowledge of the dental decoronation technique was carried on two groups: a sample of 120 dental students (5th year of dental school), from University of Cagliari, Sassari and of Chieti-Pescara (60 males and 60 females), and a group which involved 200 Italian dentists (age comprised between 25 and 45, 130 females and 70 males) enrolled at pedodontics and orthodontics Masters and CE courses (University of Roma Sapienza, Chieti- Pescara, Cagliari). The latter group's main field of work was paediatric dentistry and orthodontics, two dental specialties often involved in treating Traumatic dental injuries. RESULTS: Only 20 dentists out of the 200 interviewed answered that they knew this technique and only 5 of them proved to know it and were able to describe it correctly. No students interviewed knew this technique. CONCLUSION: It is apparent from the results of this survey that there is very little information about the dental decoronation technique both during the Degree Course in Dentistry and Post Graduate specialty programmes (Continuing Education Courses and Masters).

Coronectomy; Good or Bad?

The removal of mandibular third molars can be complicated by injury to the inferior alveolar nerve (IAN). Coronectomy retains the tooth root; this method has been found to be preferable to extraction in the context of mandibular third molars. A failed coronectomy may cause mobilization of these roots, thereby requiring a subsequent extraction. Having undergone a previous coronectomy, extraction is then safer as the roots usually migrate away from the IAN. Computed tomography is more accurate than radiography when imaging mandibular third molars pre-operatively owing to its three-dimensional nature. Longer studies need to be conducted to evaluate the long term benefits of coronectomy. CPD/CLINICAL RELEVANCE: The removal of mandibular third molars can be complicated by the presence of the close lying inferior alveolar nerve. Coronectomy can be useful in this setting and therefore it is important to be aware of the pros and cons of this technique.

[Mandibular third molar extractions with proximity to the inferior alveolar nerve canal: what are the alternatives?].

Throughout the evolution, modern diet became softer and led to less attrition and less mesial migration of teeth resulting in an increased incidence of teeth impaction. When a mandibular third molar extraction is indicated, damage to the inferior alveolar nerve (IAN) is one of the most important complications. The objective of this review is to provide an overview of the alternative treatment modalities to total removal for a third mandibular molar in cases of proximity to the inferior alveolar nerve. Among the discussed options are: Orthodontic intervention to slowly move the tooth apex away from the mandibular canal and thus reducing the potential for neural injury during extraction; staged approached involving removal of the mesial portion of the crown creating a space for mesial migration of the teeth; and Coronectomy which include removing of the tooth crown while leaving the root undisturbed.

To retrieve or not to retrieve the coronectomy root--the clinical dilemma.

UNLABELLED: Coronectomy of mandibular third molars is a well established technique that is going through a resurgence as it seems to reduce the risk of inferior dental nerve (IDN) injury. The reservation with the technique arises because of fear that the retained root will become infected and symptomatic over time. General dental practitioners will be responsible for the long-term review and care of these patients and, consequently, it is important that they are aware of the technique and its sequelae. CLINICAL RELEVANCE: Coronectomy of mandibular third molars to avoid nerve injury is becoming increasingly popular. It is important that general dental practitioners (GDPs) are aware of the immediate and later sequelae of treatment and the implication of the retained root.

[Implant therapy following trauma of the anterior teeth ­ a new method for alveolar ridge preservation after post-traumatic ankylosis and external root resorption]. / Implantattherapie nach Frontzahntrauma. Eine neue Methode zum Erhalt des Alveolarkammes nach posttraumatischerAnkylose und externer Wurzelresorption.

The therapy of traumatized front teeth with ankylosis and additional root resorption is a real challenge for the clinician. Due to the infraposition ankylosed teeth are useless and esthetically unsatisfactory. The progressive replacement resorption and the vertical growth inhibition render an intervention inevitable. In the following case report, the prophylaxis of the alveolar ridge is brought into focus. The treatment of two ankylosed teeth by decoronation, preservation of the alveolar ridge and an implant-supported supraconstruction will be presented. The additional histological assessment confirms the diagnosis and the choice of treatment.

Coronectomy may be a way of managing impacted third molars.

DATA SOURCES: TPubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL) and the grey literature database SIGLE. STUDY SELECTION: Randomised controlled trials (RCTs) and non-randomised controlled trials (CCTs) that compared coronectomy with total removal for third molar extractions with high risk of nerve injury were included. DATA EXTRACTION AND SYNTHESIS: Data were extracted independently and in duplicate by two reviewers. Risk of bias was assessed according to the Cochrane Reviewers' Handbook. Meta-analysis and sensitivity analysis were performed. RESULTS: Four studies (two RCTs and two CCTs) involving 699 patients and 940 third molars were included. Pooled risk ratios for coronectomy compared with total removal are shown in table 1.Coronectomy was changed to total removal during surgery due to root loosening or mobilisation in 2.3% to 38.3% of cases. In 0% to 4.9% of cases reoperation was required in the coronectomy group due to persistent pain, root exposure or persistent apical infections. Root migration was only reported in three studies and ranged from 13.2% to 85.9%. CONCLUSIONS: We suggest that coronectomy can protect inferior alveolar nerves in the extraction of third molars with high risk of nerve injury as compared with total removal, and that the risk ratios of post-operative infections were similar between the two surgical modalities.

Esthetic periodontal surgery for impacted dilacerated maxillary central incisors.

Clinicians do not frequently see impacted dilacerated maxillary incisors in their patients. When they do, there are several diagnostic and management challenges for correcting root dilacerations. An unfavorable esthetic outcome might occur as a result of soft-tissue complications during surgical eruption procedures. We present 2 patients with an impacted and dilacerated maxillary central incisor. Computed tomography scans with 3-dimensional reformation were used to accurately assess the positions of the dilacerated teeth, the degree of dilaceration, and the stage of root formation. The therapy primarily involved 2-stage crown exposure surgery combined with orthodontic traction. An apicoectomy was performed on 1 dilacerated tooth; the other exhibited pulp vitality. This article highlights the periodontal surgical strategies for the esthetic management of inverted crowns. Through periodontal plastic surgery and interdisciplinary cooperation, the impacted dilacerated central incisors were properly aligned, and successful esthetic results were achieved.

Coronectomy: An Alternative to Complicated Full-Bony Impacted Tooth Removal.

The removal of impacted teeth is a common office-based oral and maxillofacial surgical procedure. Complications associated with the procedure are uncommon; however, in the mandible, close proximity of the third molars to the inferior alveolar nerve can potentially lead to temporary or permanent sensory disturbances. The intentional partial odontectomy (coronectomy) procedure is a surgical option aimed at mitigating and reducing the incidence of this potential risk and complication.

Gemination or fusion? - challenge for dental practitioners (case study).

Gemination and fusion are anomalies in size, shape and structure of teeth. Gemination more frequently affects the primary teeth, but it may occur in permanent dentitions, usually in the incisor region. Geminated teeth are typically disfigured in appearance due to irregularities of the enamel. Fused teeth can have separated pulpal space, one pulp chamber and two canals or take the form of a large bifid crown with one pulpal space. It is hard to differentiate between fusion and gemination, especially if the supernumerary tooth bud is fused with the adjacent one. Usually, fusion may be differentiated from germination by a reduced number of teeth. An exception is in the unusual case in which the fusion is between a supernumerary tooth and normal tooth. A 20-year-old male referred to us at - "UniDent" - Dental Clinic, Training and Research Center. The patient complained about the large, unusual maxillary central incisors, lip irritation and aesthetic problems. According clinical examination and radiological findings, clinical diagnose was - bilateral germination of central incisors. Several treatment methods have been described in the literature with respect to the different types and morphological variations of fused and geminated teeth, including endodontic, direct\indirect restorative, surgical, periodontal and/or orthodontic treatment. Our patient has demanded for better aesthetics and he choose the treatment option to make two separate PFM crowns. In the beginning of treatment, the length of tooth 11 was 9.5mm, after prosthodontic treatment it has become 11.5mm. For tooth 21, it was 9.9 millimeter and became - 10.8 mm, while the primary width of right central incisor appeared 13.2 millimeter and was narrowed until 10.8 mm. 12.8 mm was the - width of left central incisor, which finally became - 10.4 mm. Despite the considerable number of cases reported in the literature, the differential diagnosis between these abnormalities is very difficult, as well as, to find guideline of proper outcome of treatment therapy of abovementioned abnormalities. That's why, the aesthetic rehabilitation of doubled teeth, has been suggested, to depend upon the patient's desires, but at the same time, avoid treatment plans with aggressive management.

Is endodontic treatment necessary during coronectomy procedure?

PURPOSE: Close proximity of the inferior alveolar nerve (IAN) to the third molar roots can result in nerve injuries during extraction of third molars. Consequently, it is necessary to determine the relationship of the nerve and roots to avoid damage to the IAN. Computed tomography scans are widely used to determine the correct relationship between the IAN and lower third molars. PATIENTS AND METHODS: The study consisted of 10 patients with 16 lower third molars in close relationship with the IAN who were divided into a study group and a control group. The patients in the study group were treated via coronectomies performed with endodontic treatments. The patients in the control group underwent coronectomies without endodontic treatment. The patients were followed up for at least 1 year. RESULTS: We had to extract 7 of the roots because of the infection in 8 patients belonging to the study group, which were treated endodontically. Moreover, there were 3 cases of IAN damage because of the extraction in the study group. However, in the control group, no infection was determined and IAN damage was absent. CONCLUSION: Coronectomy appears to be a reliable technique to protect the IAN from damage. This procedure has a low incidence of complications. Endodontic treatment does not affect the success of this method according to our results.

Coronectomy of a third molar with cyst lining enucleation in the management of a dentigerous cyst.

UNLABELLED: A dentigerous cyst was treated with enucleation and coronectomy of the associated tooth to minimize the risk of inferior alveolar nerve damage, resulting from direct surgical trauma or indirectly from intra-operative or post-operative jaw fracture. Radiographic monitoring over 33 months confirmed migration of the roots through healed bone and progressive obliteration of the residual pulp canal chamber. These observations are not associated with failure of the technique but are, in fact, commonly observed in successful cases of coronectomy. A brief discussion of the risks versus benefits of this treatment modality is presented with reference to the literature available. CLINICAL RELEVANCE: In selected cases, coronectomy with cyst enucleation as a one stage procedure may reduce the risk of perioperative nerve damage.

[Coronectomy. An alternative for complete removal of the third molar in the lowerjaw]. / Coronectomie. Alternatief voor volledige verwijdering van een derde molaar in de onderkaak.

Sensory impairment of the inferior alveolar nerve in the region undergoing treatment is an unfortunate complication after the surgical removal of a mandibular third molar. Coronectomy is a treatment in which only the crown portion and part of the roots of the tooth are removed. The apical portion of the roots is deliberately left in place in order to avoid damage to the nerve. In a group of 34 patients, a total of 38 coronectomies was carried out, because these patients had a radiologically determined increased risk of inferior alveolar nerve damage in case of surgical removal. The mean follow-up period was 16.7 months, ranging from 3-62 months. None of the patients experienced sensory impairment of the alveolar nerve in the region under treatment. In the case of 3 patients, roots left in place appeared to cause complaints and were removed after all. The conclusion of the study was that coronectomy seems a useful and safe treatment option.

Clinical evaluations of coronectomy (intentional partial odontectomy) for mandibular third molars using dental computed tomography: a case-control study.

PURPOSE: Studies have suggested that coronectomy reduces the risk of inferior alveolar nerve injury (IANI) when a close relationship with the inferior alveolar canal is indicated on panoramic imaging. However, the relationship between the inferior alveolar canal and the root are unclear on panoramic imaging. Our aim was to compare coronectomy with traditional extraction for the treatment of mandibular third molars that had clear high IANI risks as evaluated by dental computed tomography. PATIENTS AND METHODS: We designed a case-control study of subjects with high-risk signs of IANI on panoramic images evaluated by dental computed tomography before enrollment. The 220 patients enrolled were assigned to extraction (control group, n = 118) or coronectomy (case group, n = 102). RESULTS: The mean follow-up time was 13 months in the extraction group and 13.5 months in the coronectomy group. Six IANIs (5%) were found in the extraction group. In the coronectomy group, 1 patient (1%) had symptoms of neurapraxia, which disappeared within 1 month. Four remaining roots had signs of postoperative infection, and the patients underwent extraction of the root. No nerve damage resulted in these patients after repeat extraction. CONCLUSIONS: Coronectomy might reduce the risk of nerve injury for patients at true high risk of IANI as evaluated by dental computed tomography. A long-term postoperative review is needed to assess the incidence of root migration and the root extraction and infection rates after coronectomy.

Decoronation of an ankylosed permanent incisor: alveolar ridge preservation and rehabilitation by an implant supported porcelain crown.

Replacement resorption and ankylosis are frequently diagnosed following severe dental trauma. The complications that may develop as a result of ankylosis of a permanent incisor in children and adolescent include: esthetic compromise, orthodontic complications because of: arch irregularity; lack of mesial drift; tilting of adjacent teeth, arch length loss and local arrest of alveolar ridge growth. To avoid such complications, an ankylosed tooth should be removed before the changes become so pronounced that they compromise future prosthetic treatment. The purpose of this article was to present a case of preservation of the alveolar ridge for implant rehabilitation by utilizing decoronation for the treatment of a young permanent central incisor. An implant was inserted, without any bone augmentation procedures, followed by prosthetic porcelain crown rehabilitation. We conclude that treatment of an ankylosed young permanent incisor by decoronation may maintain the alveolar bone ridge width, height and continuity, and facilitate future rehabilitation with minimal, if any, ridge augmentation procedures.

Coronectomy to prevent damage to the inferior alveolar nerve.

Conventional wisdom advises that when a tooth needs to be extracted, the whole tooth should be removed, usually with as little surrounding bone as possible. However, the evidence to support this is not compelling, and every dentist has experienced cases where the apices of teeth are not removed for a variety of reasons and, in most cases, the patient seems to suffer no ill effects. If one extrapolates from this, it is evident that there might be instances where it is actually preferable to leave the apical part of the root rather than remove it, and this can be carried out deliberately. The usual time that one would consider this is when the inferior alveolar nerve is intimately related to the roots of the lower molar teeth, and this occurs most often in relation to the third molar. This concept of deliberately removing only the crown and part of the root of the tooth is known variously as coronectomy, partial root removal, deliberate vital root retention, or partial odontectomy.

Plain radiographs for the assessment of coronectomy: not always a case of black or white.

In recent years, coronectomy of impacted lower third molar teeth has become an increasingly popular alternative to removal. Traditionally, orthopantomograms of mandibular third molars have been used to indicate features that show that the tooth is in close proximity to, or in an intimate relation with, the inferior dental nerve. Some authors advocate coronectomy as opposed to surgical removal to reduce the risk of damage to the nerve. In our Trust during the last two years, there has been a noticeable increase in the prescription of coronectomy for the management of pericoronitis associated with mandibular third molars. The purpose of this study therefore was to examine the differences among clinicians in their assessment of the need for coronectomy using plain-view radiographs. An online survey was completed by 25 clinicians with different levels of experience from six units across the UK and Republic of Ireland. We found a wide variation in the number of coronectomies prescribed (intraclass correlation 2.67), and when prescribed, a lack of agreement about the radiographic feature that had influenced the decision. These judgments are not straightforward. They are, to some extent, subjective, and in certain cases may benefit from a team-led approach.