Anatomy and function of the canalis sinuosus and its injury prevention and treatment strategies in implant surgery. / çª¦ç®¡çš„è§£å‰–ä¸ŽåŠŸèƒ½åŠå ¶åœ¨ç§æ¤æœ¯ä¸­æŸä¼¤çš„é˜²æ²»ç­–ç•¥.

The canalis sinuosus, a canal containing the anterior superior alveolar nerve bundle, originates from the infraorbital canal and extends along the maxillary sinus and nasal cavity edges to the anterior maxilla. It was once regarded as an anatomical variation. However, with the widespread application of cone beam computed tomography (CBCT), the detection rate of canalis sinuosus in the population has increased. The canalis sinuosus exhibits diverse courses, branching into multiple accessory canals and terminating at the nasal floor or the anterior tooth region, with the majority traversing the palatal side of the central incisor. The anterior superior alveolar nerve bundle within the canalis sinuosus not only innervates and nourishes the maxillary anterior teeth, their corresponding soft tissues, and the maxillary sinus mucosa, but also relates to the nasal septum, lateral nasal wall, and parts of the palatal mucosa. To minimize surgical complications, implantologists need to investigate strategies for preventing and treating canalis sinuosus injuries. Preoperatively, implantologists should use CBCT to identify the canalis sinuosus and virtually design implant placement at a distance of more than 2 mm from the canalis sinuosus. Intraoperatively, implantologists should assess bleeding and patient comfort, complemented by precision surgical techniques such as the use of implant surgical guide plates. Postoperatively, CBCT can be employed to examine the relationship between the implant and the canalis sinuosus, and treatment of canalis sinuosus injuries can be tailored based on the patient's symptoms. This review summarizes the detection of canalis sinuosus in the population, its anatomical characteristics, and its physiological functions in the anterior maxilla, and discusses strategies for effectively avoiding canalis sinuosus injuries during implant surgery, thereby enhancing implantologists' awareness and providing references for clinical decision-making.

Assessment of canalis sinuosus, rare anatomical structure using cone-beam computed tomography: A prospective study.

Objectives: This prospective study was performed with cone-beam computed tomography (CBCT) images for evaluating canalis sinuosus (CS), determine its location and diameter in relation to gender, age, and distances from important structures, including floor of nasal cavity, incisive foramen, edge of buccal cortical bone, and palatal cortical bone. Material and Methods: The scans of 650 patients in total were included in this prospective analysis. Gender, age, the position of the CS, its presence or absence, diameter, and its location in reference to the adjacent teeth were the factors that were noted. Results: The study had 301 female participants and 349 male participants, with a mean age of 42.19. Compared to females, males had a statistically higher frequency of CS. Higher age groups showed a higher presence of CS in comparison to the other age groups. The mean distances of these parameters on the left and right side did not differ significantly. Nonetheless, the distance on both sides between CS and nasal cavity floor for males and females, as well as the diameter and border of buccal-palatal cortical bone on the right side, were statistically significant different. On the left side, both genders demonstrated significance in buccal cortical margin and nasal cavity floor. IIn addition, in females, the diameter of the CS on the right and left sides differed on average. The associations between age and number of CS, CS diameter, and number of CS versus sex were all extremely weak. Overall, the study findings showed that CS is a typical anatomical feature in anterior maxillary region, irrespective of age, or gender. Conclusion: The bony canal, CS is an obscure feature located in the frontal region of the maxilla. Surgeons can avoid complications by being aware of the auxiliary canals derived from this structure. With the use of CBCT, it is now feasible to examine the course of CS as it passes through the maxillary sinus's anterolateral wall with better radiological accuracy has already been documented.

Cone-beam computed tomography of accessory canals of the canalis sinuosus and analysis of the related risk factors.

PURPOSE: Cone-beam computed tomography (CBCT) was used in this study for evaluating the diameter, prevalence, spatial location, and risk factors of the accessory canal (AC) of the canalis sinuosus. METHODS: A comprehensive assessment of the incidence rate, diameter, three-dimensional (3D) spatial location, and direction of travel of AC was performed on 1003 CBCT images. The CBCT data were used to reconstruct a 3D model of the maxilla to determine the alveolar bone volume. The obtained data were further analyzed and processed. RESULTS: AC was present in 50.1% of images. Male patients more frequently had ACs than female patients did (P < 0.01) and was positively correlated with the maxillary alveolar bone volume (P < 0.001, OR 1.532). Age or nasopalatine canal diameter were not significantly associated with the occurrence of AC (P > 0.05). Among the 502 patients with AC, AC was present on the left side, right side, and bilaterally in 189, 98, and 215, respectively. The maximum number of ACs observed per individual was eight. The average AC diameter was 0.89 ± 0.26 mm (minimum, 0.5 mm; maximum, 2.02 mm). CONCLUSIONS: As the prevalence of AC and its trajectory display considerable variation among individuals, surgeons must consider the possibility of the presence of AC when devising surgical plans involving the anterior maxillary region.

A cone-beam computed tomography study of canalis sinuosus and its accessory canals in a South African population.

OBJECTIVES: Canalis sinuosus (CS) is a clinically relevant structure in the anterior maxilla. The present study aimed to determine the prevalence and distribution of CS and its accessory canals (ACs) in the South African population and describe its anatomical variations. METHODS: In total, 500 cone-beam computed tomography (CBCT) scans of the anterior maxilla were assessed for prevalence, sidedness, diameter, and distribution of CS. The frequency, number, diameter, configuration, and point of termination of ACs were also recorded. Statistical analysis was performed using analysis of variance, Kruskal-Wallis, chi-squared, and Fisher Exact tests with P < 0.05. RESULTS: CS was present in most cases (99.6%), and commonly occurred bilaterally (98.8%). The mean diameter of CS was 1.08 mm (range: 0.50 mm-2.39 mm). Sex, population group, and age had no significant effect on the prevalence or sidedness of CS. Additionally, 535 ACs were observed in 58.8% of the sample, with 42.9% of ACs found bilaterally and 57.1% unilaterally. The mean diameter of the ACs was 0.86 mm on the left and 0.87 mm on the right (range; 0.50 mm-1.52 mm). The majority of ACs maintained a straight vertical configuration (72.3%). ACs most commonly terminated in the anterior palatal region of the maxilla (57.2%). No significant differences were found in any groups mentioned (P > 0.05). CONCLUSIONS: A high prevalence of CS as well as ACs were observed in the sample population. Due to their clinical significance, surgical planning with the aid of high quality CBCT scans of the anterior maxilla is advisable.

Anatomical study of the canalis sinuosus in Chilean individuals by cone-beam computed tomography / Estudio anatómico del canal sinuoso en individuos chilenos mediante tomografía computarizada cone-beam

SUMMARY: The canalis sinuosus (CS) is a double-curved bone canal in the anterior region of the maxilla. The CS contains a vasculo-nervous bundle consisting of the anterior superior alveolar nerve and its corresponding arteries and veins. The CS and its accessory canals (AC) have been little described in the literature and are often omitted in imaging evaluations before procedures in the region. The object of the present study was to evaluate the frequency of the CS and its AC in Chilean individuals, and to carry out a morphometric analysis of these anatomical structures by cone-beam computed tomography (CBCT) by sex, side and age range. CBCT examinations of 28 patients were studied, evaluating the presence, diameter and terminal portion of the CS. We also evaluated the presence and number of AC, and their terminal portion. The diameter of the AC was classified as greater or smaller than 1.0 mm. Non-parametric tests were used for quantitative variables and chi-squared for qualitative variables. The SPSS v.27.0 software was used, with a significance threshold of 5 %. The CS was present in all the samples analysed, generally presenting a diameter greater than 1.0 mm. Alterations were found, and the diameter could be greater depending on the segment evaluated, however it was not affected by sex, side or age range. The terminal portion of the CS is usually located adjacent to the region of the nasal cavity. The frequency of AC was very high, and the most common location was in the region of the upper central incisor; in 61.3 % of cases their diameter ?1.0 mm. The high frequency of CS and AC shows the importance of carrying out a detailed imaging study before invasive procedures in the anterior region of the maxilla.

RESUMEN: El canal sinuoso (CS) es un canal óseo que presenta doble curvatura, ubicado en la región anterior de maxila. El CS contiene un paquete vásculonervioso formado por nervio alveolar superior anterior, arterias y venas correspondientes. El CS y sus canales accesorios (CA) han sido poco descritos en la literatura y muchas veces son omitidos en evaluaciones imagenológicas previas a procedimientos en la región. El objetivo del presente estudio fue evaluar la frecuencia del CS y de sus CA en individuos Chilenos, bien como realizar un análisis morfométrico de estas estructuras anatómicas mediante tomografía computarizada cone-beam (TCCB) según sexo, lado y rangos etarios. Fueron evaluados exámenes de TCCB de 28 pacientes. Se evaluó la presencia, diámetro y porción terminal del CS. Se evaluó la presencia del CA, cantidad y porción terminal. El diámetro del CA fue clasificado en mayor o menor a 1,0 mm. Se utilizaron pruebas no paramétricas para variables cuantitativas y chi-cuadrado para variables cualitativas. Se utilizó el software SPSS 27.0, considerándose umbral de significación de 5 %. El CS estuvo presente en todas las muestras analizadas, presentando en general un diámetro mayor a 1,0 mm. El diámetro del CS sufre alteraciones pudiendo ser mayor dependiendo de la región evaluada, sin embargo no se ve afectado por sexo, lado o rangos etarios. La porción terminal de CS suele ubicarse adyacente a la región de cavidad nasal. La frecuencia de CA es muy alta, en un 61,3 % presentan diámetro ?1,0 mm, siendo la región de incisivo central superior su ubicación más común. La alta frecuencia de CS y de CA demuestra la importancia de realizarse un detallado estudio imagenológico previo a procedimientos invasivos en región anterior de la maxila.

Canalis sinuosus: An Anatomic Repair that May Prevent Success of Dental Implants in Anterior Maxilla.

Canalis sinuosus (CS) is a neurovascular canal that corresponds to a small branch of the infraorbital canal. It contains the anterior superior alveolar nerve and vessels, supplying the anterior maxilla. Despite having been described 81 years ago, CS is not recognized by many dental practitioners and may be the cause of unintended injuries during dental procedures. The aims of this study are to report a case of a patient who suffered pain due to exposure of the CS, to provide a comprehensive review of other CS cases that were challenging to diagnose, and to propose guidelines for preoperative examination of patients undergoing surgical procedures in the anterior maxilla. The review of the literature revealed six cases, in addition to the one presented here, of unintended or potential damage to CS. Five out of seven cases were related to dental implant placement and resulted in postoperative pain and/or paresthesia. The dental implant was removed in 4 out of the 5 cases. This study reinforces the importance of awareness of CS by dental practitioners and provides a protocol for the preoperative examination of the patient to prevent avoidable injuries to CS.

Direct approach to the anterior and lateral part of the maxillary sinus with an endoscope.

OBJECTIVE: The Caldwell-Luc (CL) approach with a sublabial incision is used to manipulate the anterior wall of the maxillary sinus. Paresthesia is one of the major complications associated with the CL approach. We developed a new method, "direct approach to the anterior and lateral part of the maxillary sinus with an endoscope" (DALMA), that negates the need for a sublabial incision and minimizes dental paresthesia by reducing the risk of anterior superior alveolar nerve injury. This study aimed to describe how to perform the DALMA technique, and to review its effectiveness and associated complications. METHODS: We retrospectively reviewed 10 patients who had received DALMA. RESULTS: Ten patients underwent DALMA. The anterior superior alveolar nerve was identified in all patients. Access to the lateral side beyond the infraorbital canal and anterior wall of the maxillary sinus was achieved. CONCLUSIONS: DALMA is a simple, effective, and minimally invasive technique that can be used as an alternative to CL with sublabial incision.

Injured Anterior Superior Alveolar Nerve Endoscopically Resected within Maxillary Sinus.

Posttraumatic facial pain is due to an injured nerve, most often a branch of the trigeminal nerve. While surgical approaches to injuries of the supraorbital, supratrochlear, infraorbital, and inferior alveolar nerves have been reported, an injury to the anterior superior alveolar nerve (ASAN) has not been reported. An algorithm is proposed for the diagnosis of injury to the ASAN versus the infraorbital nerve itself. A case is reported in which pain relief was achieved by dividing the ASAN within the maxillary sinus, leaving the proximal end exposed within the sinus at the level of the orbital floor.

Accessory branch of canalis sinuosus mimicking external root resorption: A diagnostic dilemma.

The aim of this study was to recognize the importance of canalis sinuosus in Endodontics. A 60-year-old male patient reported with the chief complaint of pain and swelling in upper front tooth region for 2 weeks with a history of trauma 21 years back. Clinical examination revealed fractured tooth 21 (maxillary left central incisor) with an associated sinus tract. Radiographic examination revealed diffuse periapical radiolucency in relation to tooth 21 and external resorptive defect in apical third of the root of tooth 11 (maxillary right central incisor). Cone-beam computed tomography advised to plan surgical treatment for the same disclosed the presence of an anatomic variation of canalis sinuosus. The location and course of this canal illuded as a resorptive defect, which is a very rare occurrence. This led to a change in diagnosis with relation to tooth 11 and treatment plan was formulated accordingly.

Assessment of accessory canals of the canalis sinuosus: a study of 1000 cone beam computed tomography examinations.

The aim of this study was to verify the presence, spatial location, and calibre of the accessory canals (AC) of the canalis sinuosus by cone beam computed tomography, and their relationship to the anterior maxilla. This retrospective analysis included the scans of 1000 subjects. Parameters registered were sex, age, number of AC, presence or absence of AC with a diameter <1.0mm, AC diameter (only for AC with a diameter >1.0mm), and AC location in relation to the adjacent teeth. Males showed a statistically higher frequency of AC than females. The difference in age distribution was not statistically significant. Twenty percent of all AC presented a diameter of a least 1.0mm. The end of the AC trajectory was most frequently located palatal to the anterior maxillary teeth. All relationships analyzed here were very weak (age vs. number of AC, age vs. AC diameter, number of AC vs. sex). Overall, the results of this study showed that AC of the canalis sinuosus are a common anatomical structure in the anterior maxilla, regardless of age and sex.

Effectiveness of nasopalatine nerve block for anesthesia of maxillary central incisors after failure of the anterior superior alveolar nerve block technique

The purpose of this study was to assess the effectiveness of nasopalatine nerve block for anesthesia of maxillary central incisors after failure of the anterior superior alveolar nerve (ASAN) block technique. Secondarily, the possible innervation of the maxillary central incisors by the nasopalatine nerve was also investigated. Twenty-seven healthy, young adult volunteers (age: 17-26 years; gender: 9 males and 18 females) were enrolled in this study. All participants were undergraduate dental students of the University of Vale do Rio Verde de Três Corações. The volunteers had the anterior superior alveolar nerves anesthetized and a thermal sensitivity test (cold) was performed on the maxillary central incisors. The volunteers that responded positively to cold stimulus received a nasopalatine nerve block and the thermal sensitivity test was repeated. All participants were anesthetized by a single operator. Three patients presented sensitivity after both types of bilateral blocks and were excluded from the percentage calculations. In the remaining 24 patients, 16 had their maxillary central incisors anesthetized by the anterior superior alveolar block and 8 remained with sensitivity after the ASAN block. All these 8 patients had their maxillary central incisors successfully anesthetized by the nasopalatine block. In this study, 33.3 percent of the subjects had the innervation of one or both maxillary central incisors derived from the nasopalatine nerve, whilst most subjects (66.7 percent) had such teeth innervated by the anterior superior alveolar nerve. The nasopalatine nerve block was effective in anesthetizing the maxillary central incisors when the anterior superior alveolar nerve block failed.

O objetivo deste estudo foi avaliar a eficácia do bloqueio do nervo nasopalatino após falha na anestesia dos incisivos centrais superiores pelo bloqueio no nervo alveolar superior anterior (NASA). Secundariamente, investigou-se a possível inervação do incisivo central superior por ramos do nervo nasopalatino (NNP). Foram avaliados 27 voluntários saudáveis, adultos jovens (idade: 17-26 anos; sexo: 9 homens e 18 mulheres). Todos eram estudantes de Odontologia da Faculdade do Vale do Rio Verde de Três Corações. Os voluntários tiveram os nervos alveolares anteriores superiores anestesiados e em seguida foram submetidos a um teste de sensibilidade térmica nos incisivos centrais superiores. Aqueles pacientes que ainda apresentavam sensibilidade após o bloqueio do NASA receberam bloqueio do NNP e então o teste térmico foi repetido. Todos os pacientes foram anestesiados por um único operador. Três pacientes ainda apresentaram sensibilidade após ambos os bloqueios bilaterais (NASA e NNP) e foram excluídos das análises de percentagem. Dos 24 pacientes restantes, 16 tiveram seus incisivos centrais superiores anestesiados pelo bloqueio do NASA e 8 permaneceram com sensibilidade após este procedimento. Estes 8 pacientes submeteram-se ao bloqueio do NNP, o que resultou em sucesso na anestesia dos incisivos centrais superiores. Neste estudo, 33,3 por cento dos pacientes tinham a inervação de um ou de ambos os incisivos centrais superiores derivada do nervo nasopalatino, enquanto a maioria dos pacientes (66,7 por cento) tinha tais dentes inervados pelo nervo alveolar superior anterior. O bloqueio do NNP foi eficaz para anestesiar os incisivos centrais superiores, nos casos em que falhou o bloqueio do NASA.