Impacted mandibular third molar: Comparison of coronectomy with odontectomy

Damage to the inferior alveolar nerve (IAN) while extracting lower third molars is often caused by the intimate relationship between the nerve and the roots of the teeth. The aim of this study was to compare the sequelae of coronectomy with odontectomy in impacted mandibular third molars. Patients and Methods: This study included thirty patients which were divided into two groups, Group-I (test group) including 15 patients undergoing coronectomy and Group-2 (control group) of 15 patients undergoing odontectomy. Investigations included digital orthopantomogram. The parameters for this study included pain, swelling, nerve paresthesia, trismus, postoperative infection, postoperative wound dehiscence, postoperative pocket depth, and migration. Results: In Group-1 (coronectomy group), the patients underwent follow-up for 6 months to evaluate migration of the retained mandibular third molar root which was in proximity with the IAN. There was a mean increase in migration when the distance from the inferior border of IAN until the apex of the retained mandibular third molar root was measured which was by 3.43 mm after 6 months of follow up. Conclusion: On statistical analysis, the result in this study showed no statistical difference in both the groups in all the parameters that were taken.

Coronectomía en terceros molares mandibulares como alternativa de tratamiento seguro en la prevención del daño al nervio alveolar inferior: revisión bibliográfica y reporte de 30 casos / Coronectomy in third mandibular molars as an alternative treatment to prevent damage to the inferior alveolar nerve: bibliographic review and 30 cases report

La lesión del nervio alveolar inferior (NAI) al extraer los terceros molares mandibulares esa menudo causada por la íntima relación entre el nervio y las raíces dentarias. La técnica de coronectomía ola retención intencionada de raíz, podría mitigar este problema. Treinta pacientes fueron sometidos a coronectomia en 30 terceros molares mandibulares con seguimiento de al menos 6 meses. Todos los pacientes fueron radiografiados antes de la intervención, inmediatamente después de la operación, y después de 6meses. La técnica se realizó con protección del nervio lingual como parte del procedimiento quirúrgico. Todas las raíces quedaron al menos 3 mm por debajo de las tablas óseas bucal y lingual. No hubo ningún caso de daño del NAI. Hubo un caso de afectación transitoria del nervio lingual, probablemente por el uso del retractor lingual. Un paciente requirió la retirada posterior de las raíces de los terceros molares, debido a la falta cicatrización, y otro paciente requirió la retirada posterior de una raíz a causa de migración posterior ala superficie. La migración de las raíces se observó en aproximadamente el 30 % de los pacientes durante un período de 6 meses. La coronectomia parece ser una técnica viable en aquellos casos en que la extracción completa del diente podría poner al NAI en un riesgo considerable de daño. La técnica parece estar asociada con una baja incidencia de complicaciones, pero la migración posterior de las raíces puede ser un problema en el largo plazo.

The inferior alveolar nerve (IAN) injury to remove the third molars is often caused by the intimate relationship between the nerve and the roots of the teeth. Coronectomy technique or intentional root retention, may minimize this problem. Thirty patients underwent coronectomy in 30 third molars with follow up of at least 6 months. Coronectomy technique deliberately protected the lingual nerve as part of the surgical procedure. All roots were at least 3 mm below the buccal and lingual bony walls. All patients were radiographed preoperatively, immediately postoperatively, and after 6 months. There were no cases of IAN damage involved in this study of 30 patients who underwent 30 coronectomies. There was one case of transient lingual nerve involvement, probably by the use of lingual retractor. One patient required subsequent removal of the roots of both lower third molars, due to lack of healing, and one patient required subsequent removal of a root cause of migration back to the surface. migration of the roots was observed in approximately 30 percent of patients during a period of six months. Coronectomy seems to be a viable technique in those cases where the removal of all tooth could put the IAN at considerable risk of damage. The technique appears to be associated with a low incidence of complications, but the subsequent migration of the roots can be a problem in the long term.

Coronectomia em terceiro molar inferior: relato de casos / Coronectomy in lower third molar: case reports

O princípio da coronectomia ou odontectomia parcial intencional é a remoção da coroa do dente, deixando a raiz in situ. Essa técnica, quando aplicada para a remoção de um terceiro molar ou qualquer dente posterior incluso na mandíbula, tem o intuito de evitar danos ao nervo alveolar inferior. O objetivo do presente estudo foi relatar dois casos clínicos de terceiro molar inferior incluso apresentando suas raízes em íntima relação com o canal mandibular, e, para o tratamento, foi realizada a técnica da odontectomia parcial intencional. Informações sobre o déficit neurosensorial, infecção pós-operatória, tempo do pós-operatório e a taxa de sucesso são enfatizadas no estudo. Conclui-se que a odontectomia parcial intencional é uma técnica previsível e de fácil execução, podendo ser realizada em ambiente ambulatorial. Trata-se de um procedimento alternativo, útil nas extrações de terceiros molares inferiores inclusos que apresentam relação de proximidade com o canal mandibular... (AU)

The principle of coronectomy or intentional partial odontectomy is the removal of the tooth crown, leaving the root in situ. This technique aims to prevent damage to inferior alveolar nerve while applying to removal a third molar or posterior tooth impacted in mandible. In this study, we report two clinical cases with the impacted lower third molar presented roots in close proximity to the mandibular canal and the treatment was performed by intentional partial odontectomy. Neurosensory deficits, postoperative infection, periods off follow up and surgical outcomes were emphasized in this study. We concluded that the intentional partial odontectomy is a foreseeable technique and easy to perform in an outpatient setting. It is an alternative procedure in the extraction of impacted lower third molar that has a close relationship with mandibular canal... (AU)

A CLINICAL STUDY OF ODONTECTOMY IN IMPACTED MANDIBULAR THIRD MOLARS

Surgical removal of impacted mandibular third molars frequently require tooth sectioning or bone removal. In this study, 361 mesioangular or horizontal impacted mandibular third molars are removed surgically by tooth section, the methods of tooth section are classified as 4 stages and 12 grades in the number of times and technics of crown or roots section and difficulties. Grades and their cases are followings: 1. occlusal crown first section(100, 28%) 2. distal crown first section(69, 19%) 3. occlusal crown second section(29, 8%) 4. distal crown second section(52, 14%) 5. occlusal crown first section and root section(10, 3%) 6. distal crown first section and root section(27, 7%) 7. occlusal crown third section(3, 1%) 8. distal crown third section(22, 6%) 9. occlusal crown second section and root section(13, 3%) 10. distal crown second section and root section(17, 5%) 11. occlusal crown third section and root section(2, 1%) 12. distal crown third section and root section(17, 5%)