| [Objective]The purpose of the present study was to analyze mandibular implant-related anatomical structures and to show incidence and morphological characteristics of each anatomical structure for providing useful information for dental implant treatment in mandibular region.[Methods]Experiment 1 A total of 1008 patients were enrolled in this study in The Affiliated Stomatology Hospital of Kunming Medical University. The medial lingual foramen, medial lingual canal, lateral lingual foramen, mandibular incisive canal and other anatomical structures of mandibles were measured and analyzed by the CBCT viewer. Observations included: 1. The incidence, length, type, of the medial lingual foramen and the distance to the lower edge of the mandible, and the distance to the alveolar crest. 2. The incidence, length, type, of the lateral lingual foramen and the distance to the lower edge of the mandible, and the distance to the alveolar crest. 3.The incidence and length of mandibular incisive canal. 4. Incidence of the anterior loop of the inferior alveolar nerve. The data were grouped according to gender group and age, and the differences and analyzed statistically.Experiment 2 (1) 70 mandibular specimens were analyzed for incidence of medial lingual foramen and lateral lingual foramen. The distance between the median lingual foramen and the lower edge of the mandible and the alveolar crest were measured. (2) Chosen the mandibular specimens which had a distinct medial lingual foramen and then injection of contrast agent into foramen. The CBCT was taken before and after injection of the contrast agent. The data were analyzed by Simplant 17.0 for observation of the contrast agent distributions in the mandible.[Results]Experiment 1: A total of 1008 patients with CBCT data were collected, including 521 males (51.7%) and 487 females (48.3%). The youngest was 18 years old, the oldest was 84 years old, the average age was 41 years old.The incidence of 1.observation results: (1) .the medial lingual foramen was found to be present in 916 patients of 1008 patients (90.9%) by CBCT. Of these, 674 cases (66.9%) had only one medial lingual foramen, 221 (21.9%) of them had two medial lingual foramen, and 21(2.1%) of them had three medial lingual foramen.(2). There were 547 patients(54.3%) who had observed lateral lingual foramen, with a rate of 54.3%. There were 365 patients just had only one lateral lingual foramen, 178 patients (17.7%) with two lateral lingual foramen, 3 cases (0.3%) with three lingual foramen, and 1 (0.1%) with only four lingual foramen. (3). The incidence rate of left and right mandibular incisive canal was 87% (887 cases). (5).The location of the lateral lingual foramen was basically the same on the left and right sides, from below the mandibular incisors to below the mandibular first molar, and the most common appearances on the left side were the mandibular first premolars and the second premolar between the bottom of the second premolar, on the right side. 2.The length of the measurement results: (1)According to the position of medial lingual foramen in the mandibular from top to bottom, respectively, named the first medial lingual foramen (canal), the second medial lingual foramen (canal) and the the third medial lingual foramen (canal), were recorded as z1, z2 and z3. According to the classification of Thompson and the location of the middle tongue relative to the location of the chin, it was divided into three categories: Supraspinous forame, Interspinous foramen and Infraspinous foramen. The average length of the first medial lingual canal was 6.48 ± 1.64 mm,and the average length of the alveolar crest was 20.50 ± 4.20mm, and 65.5% was the Supraspinous forame, 20.8% for the Interspinous foramen, 13.7% for the Infraspinous foramen .The average length of the second lingual canal (z2) was 6.134 ± 1.929mm,and 2.9% was the Supraspinous forame, 6.6% for the Interspinous foramen, 90.5% for the Infraspinous foramen. The third lingual canal (z3) the average length of 27.8 ±2.58mm, all for the Infraspinous foramen. (2) The average length of the right side of the mandibular incisive canal was 6.03 ±1.56mm,the average distance to the alveolar crest was 23.07 ± 3.32mm,and the average distance to the lower edge of the mandible was 8.98 ± 2.25mm. The average length of the left side of the tongue was 6.03 ±1.67mm, the average distance to the alveolar crest was 22.89 ± 3.19mm, the average distance to the lower edge of the mandible was 8.96 ± 2.03mm. (3) The average length of the left incisor was 9.46 ± 2.96mm,the average distance to the alveolar crest was 22.89 ± 3.19mm,and the average distance to the lower edge of the mandible was 8.96 ± 2.03mm. The mean length of the right incisor was 9.46 ± 3.14mm,the average distance to the alveolar crest was 23.07 ± 3.32mm,and the average distance to the lower edge of the mandible was 8.98 ± 2.25mm. There was no statistically significant difference in the length of the left and right incisors (P <0.05).(4)Z1 to the alveolar crest distance, Z1 to the lower edge of the mandible, CR to the alveolar crest distance,CL to the alveolar crest distance and CL jaw to the lower edge of the distance of the six measurements in gender The difference was statistically significant.Experiment 2: (1) 70 mandibular specimens, discharge damage, done special treatment and other factors could not observe the anatomical structure of the specimen,the final successful observation of the specimens of 62. (2) A total of 59 of the 62 specimens showed a medial lingual foramen,with a probability of 95.2%,of which 29 specimens appeared in 1 foramen (46.8%), 26 specimens appeared in 2 foramen(41.9%), 4 specimens appeared 3 foramen (6.5%). (3) A total of 29 specimens of 62 specimens appeared lateral lingual foramen, the rate of 46.8%, which appeared in a foramen of 16 specimens (25.5%), there were two foramen of 10 (16.1%), there were three foramen (4.8%). (4) The contrast agent was injected and introduced into the Simplant analysis results: 640.98±378.51 mm3 were measured on the larger side 510.26 ± 322.94 mm3, and the difference between the two sides was p = 0.336(Mann-Whitney U test). After injection, the total volume was 295.22 ± 115.91mm3,the larger side was 212.34 ± 85.08 mm3, the smaller side was 82.88 ± 40.61 mm3, and the volume of the two sides was p = 0.000 (Mann-Whitney U test), showed a statistical significance.[Conclusion]1.Incidence of mandibular median lingual foreman was relatively high (90.0%),suggesting keeping auctions during mandibular implant placements. 2.The incidence of lateral lingual foreman was 54.3%, the highest incidence of location was the mandibular premolars, suggesting keeping auctions during mandibular implant placements in this premolar areas. 3.This study found that the incidence of mandibular incisive canal was high, suggesting keeping auctions during mandibular implant placements. 4.The incidence of direct observation of the mandibular was similar to the measurements on the CBCT.5.The mandibular contrast agent injection found that the distribution was uneven, which provide valuable information for anatomy researches in oral and maxillofacial region. |
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