Shape, height, and location of the lingula for sagittal ramus osteotomy in Thais

Efficacy of the Coronoid Notch and Occlusal Plane As Predictable Landmarks for Determining the Medial Cut Height in Bilateral Sagittal Split Osteotomy: A Split-Mouth Observational Study

AIM

This split-mouth observational study was conducted to assess the reliability and safety of using the coronoid notch and occlusal plane as landmarks to aid surgeons during bilateral sagittal split osteotomy (BSSO).

MATERIALS AND METHODS

Thirteen patients between the ages of 18 and 30 years, with class II and class III mandibular skeletal malocclusion requiring BSSO, were randomly selected and assigned to each of the study and control groups. A split-mouth study was chosen to conduct this research. Cone beam computed tomography (CBCT) imaging was conducted before the surgery to evaluate the anatomical structure, and three predefined points were marked at the superiormost point of the mandibular foramen, the inferiormost point of the mandibular foramen, and the deepest point of the sigmoid notch. A conventional sagittal split osteotomy was carried out in the control group. Preoperative values were obtained in the study group using the CBCT imaging technique by drawing an imaginary line from the inferiormost part of the mandibular foramen to the line corresponding to the occlusal plane that extended beyond the last molar. The lingual flap reflection was restricted to the internal oblique ridge. The posterior border of the mandible was not reflected. The measurements acquired via CBCT imaging were accurately transferred to the intraoperative surgical site using a vernier caliper. This facilitated the precise completion of the horizontal osteotomy, ascending ramus cuts, and vertical osteotomies. BSSO was performed, the mandibular setback or advancement was done with intermaxillary fixation, and the procedure was completed by rigid fixation. Types of lingual splits, types of lateral bone cut ends (LBCEs), any unfavorable split, and the time taken for the surgery (in minutes) were assessed.

RESULTS

The surgery time in the control group (20.1538 ± 2.85325 min) was found to be higher than that in the study group (17.6154 ± 3.59487 min), with a p-value of 0.02. No significant differences were observed when assessing the presence of unfavorable splits in both groups (p = 0.500). Buccal LBCEs were the most prevalent, followed by inferior types. Type I lingual split was the most common in the study group (70%).

CONCLUSION

This technique offers a dependable anatomical reference and significantly reduces surgical time for beginners. Additionally, the patterns of the lingual split were correlated with the types of lateral bone cut ends.

Variations of the Lingula and Mandibular Ramus in the Context of Sagittal Split Ramus Osteotomy: A Cone Beam Computed Tomography Study Supporting an Ethnic-Centric Approach to Orthognathic Surgery

OBJECTIVES

To investigate the ethnic variations concerning the lingula and ramus of the mandible, with particular emphasis on sagittal split ramus osteotomy (SSRO) in orthognathic surgery.

MATERIALS AND METHODS

This study examined Cone beam computed tomography (CBCT) scans from the Kenyan and Malay populations. Lingula morphology was classified into four categories. Morphometric measurements included lingula size, height above the occlusal plane, distance to the second mandibular molar, and distance from its apex to all four mandible borders. Regarding the ramus of the mandible, the thickness of each cortical plate, trabecular bone, and overall thickness were determined at two points. Furthermore, points of fusion of cortical plates were determined in both the vertical and horizontal planes.

RESULTS

Among Kenyans, the triangular shape was most common (46.5%, n = 80 sides), while truncated was most common among Malays (34.4%, n = 57 sides). The overall mean size of lingula differed significantly between Kenyan (7.37 ± 2.19 mm) and Malay (4.14 ± 2.50 mm) populations (p<0.001). The lingula was more located postero-superiorly in Kenyans compared to Malays (p < 0.001). The mean distance from the distal aspect of the second mandibular molar to the lingula was 38.37 ± 4.98 mm among Kenyans, in contrast to 31.95 ± 0.03 mm among Malays (p < 0.001). The Malays exhibited a thicker mandible with a larger trabecular distance (5.99 ± 1.41 mm and 3.41 ± 1.29 mm, respectively) than Kenyans (5.28 ± 1.39 mm and 1.98 ± 0.98 mm, respectively) (p < 0.001). The points of fusion of the cortical plates differed significantly between Kenyans and Malays.

CONCLUSION

This study focuses on two ethnic groups, Kenyans and Malays, and brings to light the ethnic-based differences in the position of the lingula and the dimensions of the mandibular ramus, both of which are essential considerations in orthognathic surgery. Preoperative consideration of such variations is warranted, potentially mitigating iatrogenic injuries and enhancing successful patient outcomes.

Determining the position of the lingula and the mandibular foramen using the antilingula in orthognathic surgery

BACKGROUND

The antilingula located on the lateral surface of the mandibular ramus has been served as a surgical landmark for the mandibular foramen on the medial surface for decades. However, whether the antilingula truly represents the lingula which is the bony prominence overlapping the mandibular foramen, or the foramen itself, is still unclear. This study thus aimed to examine the position of the antilingula in relation to three reference points: the lingula, the anterior and the posterior borders of the mandibular foramen, as well as to the reference plane used in the inferior alveolar nerve block, and to the posterior border of the mandible.

METHODS

This observational study was performed in 113 Thai dry mandibles. The antilingula were identified followed by transferring the reference points to the lateral surface. The distances from the antilingula to the reference points, the reference plane and the posterior border of the ramus were then measured. Chi-square test was calculated for side-dependency of the antilingula. Paired t-test was calculated for difference in measurements in left and right sides.

RESULTS

The antilingula could be identified in 92.48% of the mandibles with 86.67 - 90.00% accuracy and 86.67% reliability. There was no significant difference in the presence of the antilingula on left and right sides (p = 0.801). Only 2.5% and 0.83% of the antilingula correspond to the lingula and the anterior border of the mandibular foramen, respectively. However, 85% of the reference points were located within 11 mm radius. The antilingula was found located 2.80 mm inferior to the reference plane and 16.84 mm from the posterior border of the ramus.

CONCLUSIONS

The antilingula does not concur with the reference points on the medial surface. Our study also suggests that the safe area for vertical osteotomy is 11 mm posterior to the antilingula or at 30% of the length from the posterior border parallel to the occlusal plane. The use of more accurate techniques in localizing the mandibular foramen combined with the antilingula is more recommended than using the antilingula as a sole surgical guide.

Evaluation of the differences in the localization of the lingula mandibulae according to pubertal development in children: A new anthropological and forensic approach

OBJECTIVE

This study aims to investigate changes in lingula mandibulae localization before and after puberty and sex differences.

DESIGN

288 panoramic radiographs evaluated retrospectively were divided into four groups according to pubertal development: under and over 10 years old for females and under and over 11 years old for males. Four anatomic sites were used as reference points: (a) the anterior border of the ramus; (b) the posterior border of the ramus; (c) the deepest point of mandibular notch; and (d) the angulus mandibulae. The ratio of the distances from the lingula mandibulae to points (a) and (b) and the ratio of the distances from the lingula mandibulae to points (c) and (d) were determined. Two-way ANOVA was performed to assess differences between subgroups based on sex and puberty, and a Bonferroni post-hoc test was performed for multiple comparisons.

RESULTS

Puberty and sex has a significant interaction effect on the vertical location of the lingula mandibulae. Postpubertal lingula mandibulae is positioned proportionally more anteriorly by prepubertal localization. In addition, the lingula mandibulae is situated more posteriorly in females compared to males. A significant interaction effect of puberty and sex was observed in relation to the vertical positioning of the lingula mandibulae.

CONCLUSIONS

The spatial localization of the lingula mandibulae and its spatial displacement with age can be used both in estimating sex and the onset of puberty. Changes in the localization of lingula mandibulae according to pubertal development and sex can be used in forensic and anthropological contexts.

Evaluation of Mandibular Lingual and Foramen Location in Class I, Class II, and Class III Patients and its Significance in Sagittal Split Ramus Osteotomy

The precise location of the mandibular lingual (ML) and foramen (MF) is clinically significant because they are crucial anatomic markers for the inferior alveolar nerve protection in sagittal split ramus osteotomy. To determine the position of the ML and MF among subjects with class I, class II, and class III skeletal patterns to obtain information that could be useful for interventions in mandibular ramus. A retrospective study of 324 mandibular ramus from 162 patients was performed to evaluate the distance from the MF to the occlusal plane (OP) and the distance of the ML to the MF, OP, and the margin of the mandible ramus. The MF was more often located below the OP in class III (55.1%), compared with class I (29.0%) and class II (45.3%) patients (P<0.05). The distance from the ML to the MF in skeletal Class III patients (10.15 ± 1.56 mm) was found to be greater than class I (9.25 ± 1.52 mm) and class II (8.34 ± 1.79 mm) patients (P<0.001). And the distance from the ML to the OP was shown to be longer in class III (9.40 ± 2.53 mm) than in class I (6.85 ± 2.55 mm) and class II (6.99 ± 2.53 mm) patients (P<0.001). Therefore, we believe that a low medial horizontal cut at the height of OP is dangerous for Class III patients. And the safe zone for the high medial horizontal cut over the ML should be determined according to the patient's skeletal patterns.

Determining the safety margin of mandibular lingula in sagittal split ramus osteotomy

PURPOSE

The anatomical position of the lingula is clinically very important to prevent injuries during sagittal split ramus osteotomy. Our study aims to evaluate the localisation of the lingula by cone beam computed tomography (CBCT) and to compare the localisation of the lingula between malocclusion, gender, and lingula types.

METHODS

A retrospective study was conducted to evaluate the shape and location of the lingula using CBCT. A total of 250 CBCT images were included in this study. The lingula was classified as nodular, assimilated, truncated, or triangular type. Six defined distances from the top of the lingula were measured: anterior border of the ramus (L-A), posterior border of the ramus (L-P), internal oblique ridge (L-IOR), mandibular notch (L-N), and distal surface of the mandibular second molar (L-M2) and occlusal plane (L-OP). The measured distances were compared between gender, malocclusion, and lingula types.

RESULTS

The most common type of lingula was nodular (32.4%). The L-N, L-P, L-M2, and L-OP distances between genders were statistically higher in male patients than in female patients. The L-IOR, L-M2, and L-OP distances exhibited statistically significant differences found between malocclusions. No statistically significant difference was found when the distances of the lingula to the anatomical points were compared between the lingula types.

CONCLUSION

These variations in positioning of the lingula depending on the dysmorphoses are developing towards a systematic 3D examination before any mandibular osteotomy to precisely visualize the position and shape of the lingula.

A detailed radiomorphometric analysis of the mandibular foramen, lingula and anti-lingula with a special emphasis on mandibular prognathism

INTRODUCTION

The aim of this study was to evaluate radiomorphometric differences of mandibular foramen (MF), lingula (Li), and anti-lingula (AL) between prognathic and non-prognathic patients, using cone-beam computed tomography (CBCT).

METHODS

A total of 228 3D CBCT images of 57 prognathic and 57 non-prognathic patients were retrospectively evaluated. The distances between MF or Li to occlusal plane (OP), anterior border of ramus (AR), posterior border of ramus (PR), sigmoid notch (SN), gonion (Go) and distances Li to MF were measured. The presence of AL, and the distances to Li were also assessed in both groups.

RESULTS

In prognathic patients the mean distances of MF-AR and Li-PR were lesser, and Li-OP was greater (p < 0.05). However, distances from MF or Li to the other ramal landmarks were similar in both groups (p > 0.05). Presence of AL was found at 53 sides in prognathic and 20 sides in non-prognathic groups (p < 0.05). The horizontal distance of Li-MF was greater in prognathic patients (p < 0.05). On the other hand, there was no difference between groups regarding the horizontal distance of Li-Al, and the vertical distances of Li-MF and Li-AL (p > 0.05).

CONCLUSION

The present study provided valuable data regarding morphological differences of MF-AR, Li-MF and Li-OP, which should be considered in the preoperative assessment of patients with mandibular prognathism. Presence of AL was more common in prognathic patients and mainly located above Li. 3D CBCT applications facilitated assessment of AL and its relationship with Li.

Morphological Study of the Mandibular Lingula and Antilingula by Cone-Beam Computed Tomography

The patterns of the lingula and antilingula are crucial surgical reference points for ramus osteotomy. Cone-beam computed tomography (CBCT) provides three-dimensional images, and patient radiation dose is significantly lower for CBCT than for medical CT. The morphology of the mandibular lingula and antilingula of ninety patients (180 sides) were investigated using CBCT. The lingula were classified as having triangular, truncated, nodular, and assimilated shapes. The antilingula were classified as having hill, ridge, plateau, and plain shapes. The patients' sex, skeletal patterns (Classes I, II, and III), and right and left sides were recorded. The most to least common lingula shapes were nodular (37.8%), followed by truncated (32.8%), triangular (24.4%), and assimilated (5%). The most to least common antilingulae were hill (62.8%), plain (18.9%), plateau (13.9%), and ridge (4.4%) patterns, respectively. The lingula and antilingula had identical patterns on both sides in 47 (52.2%) and 46 patients (51.1%), respectively. Sex and skeletal pattern were not significantly correlated to lingula and antilingula shapes. No significant correlation was observed between lingula and antilingula shapes.

Morphological Analysis of the Mandibular Lingula and Its Relation to Antilingula Using Cone-Beam Computed Tomography in the Saudi Population

Adequate knowledge of the anatomy of the medial aspect of the mandibular ramus is essential in order to prevent inferior alveolar nerve anesthetic failure and nerve injuries associated with mandibular ramal surgical procedures. The purpose of this study was to assess the morphology of the lingula and analyze the correlation of presence probability between the lingula and antilingula using cone-beam computed tomography (CBCT). Three-dimensional images reconstructed from mandibular CBCT images of 125 Saudi individuals (250 sides), aged 16-36 years, were retrospectively evaluated for distribution in the shape of the lingulae. Additionally, the presence probability of the lingula and antilingula was assessed with respect to gender and the mandible (unilateral and bilateral), and correlation between the variables was analyzed. A nodular shape of the lingula was most commonly found (37.6%) followed by a triangular shape (30%). No significant differences were observed between the genders with regard to the presence of the lingula (p = 0.108) and antilingula (p = 0.530). Gender was non-significantly correlated with the presence of the lingula and antilingula, whilst the presence of lingula showed a significant but weak correlation with that of the antilingula (r_s = 0.221; p = 0.000). The present study provides information regarding morphological variations of the mandibular lingula in the Saudi population. The presence of the lingula was unassociated with that of the antilingula and hence consideration of the antilingula as the absolute landmark for mandibular ramus surgical procedures seems insufficient.

Locating the Mandibular Lingula Using Cone-Beam Computed Tomography: A Literature Review

This study aimed to review the literature on adult mandibular lingula (ML) locations and related distances determined using cone-beam computed tomography (CBCT). A search was conducted for studies on CBCT using the following databases: PubMed, Web of Science, and Embase. The search results were limited to studies published between 1970 and 2021. The inclusion criteria were the investigation of ML location, CBCT, and participants aged ≥18 years. Eligible studies were examined for the distances from the lingual tip to the anterior ramus border, posterior ramus border, sigmoid notch, inferior ramus border, and occlusal plane. Eight studies on CBCT qualified for inclusion in the study. The mean distances from the ML to the anterior ramus border were 15.57 to 20 mm. In most of these, the ML was located above the occlusal plane. No significant differences were observed in the location and related distances for the ML among patients of different sexes, ethnicities, or skeletal patterns.

Morphological Investigation of Mandibular Lingula: A Literature Review

Purpose: The purpose of the study was to review the literature on the shape of the mandibular lingula. Methods: English articles published from 1970 to 2021 in databases (PubMed, Web of Science, and Embase) were selected. Articles meeting the search strategy were evaluated based on the eligibility criteria (participants aged 18 years and over). Dry mandibles and cone beam computed tomography (CBCT) images were used as research materials. The shapes of mandibular lingula were classified as triangular, truncated, nodular, and assimilated. Results: Based on the eligibility criteria, 10 articles (six with dry mandibles and four with CBCT images) were selected for full-text reading and detailed examination. In the dry mandible group, triangular, truncated, nodular, and assimilated lingula were observed on 446, 398, 232, and 69 sides, respectively. In the CBCT group, nodular, truncated, triangular, and assimilated lingula were observed on 892, 517, 267, and 88 sides, respectively. Therefore, the most common lingula types in the dry mandible and CBCT groups were different. The assimilated type was the least common in both groups. Conclusion: In the dry mandible group, the most common lingula type was triangular, followed by truncated, nodular, and assimilated types. In the CBCT group, the most common lingula type was nodular, followed by truncated, triangular, and assimilated types. There were no significant differences in lingula types between the left and right sides of the mandible.

Cross sectional analysis of mandibular anthropometric points using CBCT to derive biometric measurements for a safer approach to mandible osteotomies

Purpose: This study aims to derive a series of biometric measurements using cone-beam computed tomography (CBCT) from a cross sectional group of population to help the surgeon accurately locate the mandibular foramen and the mental foramen during mandibular osteotomies. Methods: CBCT images of 800 subjects were evaluated. Various measurements were noted and compared between the two sides of the mandible in and between the sexes. Result: Statistically significant values were noted between the right and left sides of Line X to Point A in female subjects, Line Z & Line B only in male subjects and Line X’ in both male and female subjects. However, Line Y was found to be significant when comparing both sides in both males and females and also on correlation between the genders. Conclusion: Although the identification of the mandibular lingula and anatomical landmarks is an important step during mandibular osteotomies, the position of one side, however, cannot be blindly extrapolated to the contra lateral side. Also, pre operative CBCT is a useful tool to derive measurements which when transferred clinically during the surgery gives an accurate and safe approach for localisation of lingula, thus reducing the incidence of post operative neurologic morbidities.

Correlation between the Mandibular Lingula Position and Some Anatomical Landmarks in Cone Beam CT

BACKGROUND

the position of the mandibular lingula (Li) affects the success rate of the inferior alveolar nerve block (IANB) and ramus osteotomies. This study evaluated the position of the Li, to investigate the anatomical relationship between the Li and some anatomical measurements using cone beam computed tomography (CBCT).

METHODS

201 hemimandibular CBCTs of 111 patients (43 males and 68 females; 18 to 88 years old) were retrospectively evaluated. The Li location was determined from the lingula tip to: the occlusal plane, the anterior and posterior borders of the mandibular ramus, the lower border of the mandible, the distal surface of the mandibular second molar, and the mandibular notch. We evaluated the correlations between the Li and the anteroposterior diameter of the mandibular ramus; the vertical distance between condyle and mandibular angle; the mesial-distal diameter of the first, second, and third mandibular molar, the intercanine distance, the intermolar distances among the first, second, and third mandibular molars; the distance between the intermolar line of the first molar and midline, and the length of the mandibular body.

RESULTS

the vertical distance of the Li from the occlusal plane was 11.22 ± 4.27 mm. Some parameters significantly correlated with the anatomical measurements taken into consideration.

CONCLUSIONS

the present study provides new information concerning the Li and mandibular anatomy in the Italian population. Moreover, by correlating some anatomic measurements to the Li position, the localization of the Li is made possible, indirectly through the measurement of some distances between anatomical landmarks.

Dimension and Location of the Mandibular Lingula: Comparisons of Gender and Skeletal Patterns Using Cone-Beam Computed Tomography

Objective

The study aimed to investigate and measure the anatomical relationship between the mandibular lingula (Li) and skeletal patterns using cone-beam computed tomography (CBCT). Materials and Methods. In total, 72 participants (23 men and 49 women) were categorized into three groups according to their skeletal patterns (specifically, the A point–nasion–B point (ANB]) angle) as follows: Class I (0° < ANB < 4°), Class II (ANB ≥ 4°), and Class III (ANB ≤ 0°). The CBCT images of 144 rami were collected, and the distance from the Li to the external oblique ridge (Li-EOR), internal oblique ridge (Li-IOR), posterior border of the ramus (Li-PBR), inferior border of the ramus (Li-IBR), sigmoid notch (Li-Sm), and mandibular foramen (Li-MF) was examined. The Li-hMF (horizontal distance from the Li to the MF) and Li-vMF (vertical distance from the Li to the MF) were measured. The comparisons of gender, side (right and left), and skeletal patterns were then evaluated by statistical analysis.

Results

The values of the Li-EOR and Li-PBR (19.99 mm and 15.93 mm, respectively) were significantly higher in men than in women (18.85 mm and 14.89 mm, respectively). Moreover, the Li-IBR was higher in men (32.91 mm) than in women (30.40 mm). Both sides (right and left) and skeletal patterns demonstrated that the Li-EOR, Li-IOR, and Li-PBR were not significantly different. Pearson's correlation test reported a strong correlation between the Li-EOR and Li-IOR (r=0.610).

Conclusion

The distances from mandibula lingula to the external oblique ridge, posterior border of ramus, and inferior border of ramus were significantly longer in men than in women. Similarly, both horizontal and vertical distances from the lingula to the mandibular foramen were significantly longer in men than in women. Therefore, the results demonstrated that the Li was longer and more protruding in men than in women. With respect to the horizontal distance from the mandibular lingula to the mandibular foramen, of the three types of the skeletal system (Class I, Class II, and Class III), Class III was the significantly largest.

Cone-beam computed tomography of mandibular foramen and lingula for mandibular anesthesia

Purpose

The positions of the mandibular foramen (MnF) and the lingula affect the success rate of inferior alveolar nerve block. The objective of this study was to investigate aspects of the MnF and the lingula relevant for mandibular block anesthesia using cone-beam computed tomography (CBCT).

Materials and Methods

Fifty CBCT scans were collected from a picture archiving and communications system. All scans were taken using an Alphard Vega 3030 (Asahi Roentgen Co. Ltd., Kyoto, Japan). Fifty-eight MnFs of 30 subjects were included in the study. The position of the MnF, the size of the MnF, the position of the lingula, the size of the lingula, and the shape of the lingula were measured and recorded. All data were statistically analyzed at a significance level of P<0.05.

Results

The position of MnF was 0.1 mm and 0.8 mm below the occlusal plane in males and females, respectively. The horizontal position of the MnF was slightly anterior to the center of the ramus in males and in the center in females (P<0.05). The vertical position of the MnF was lower in females than in males (P<0.05). The MnF was an oval shape with a longer anteroposterior dimension. The height of the lingula was 9.3 mm in males and 8.2 mm in females. The nodular type was the most common shape of the lingula, followed by the triangular, truncated, and assimilated types.

Conclusion

CBCT provided useful information about the MnF and lingula. This information could improve the success rate of mandibular blocks.

Measurement of mandibular lingula location using cone-beam computed tomography and internal oblique ridge-guided inferior alveolar nerve block

Objectives

Inferior alveolar nerve block (IANB) is the most frequently used treatment for mandibular molars. Successful IANB requires insertion of the dental needle near the mandibular foramen. In this study, we aimed to analyze the anatomic location of the mandibular lingula and evaluate the effects of internal oblique ridge (IOR)-guided IANB.

Materials and Methods

The location of the mandibular lingula was measured using cone-beam computed tomography images of the mandibles obtained from 125 patients. We measured the distances from the occlusal plane to the lingula and from the IOR to the lingula in 250 mandibular rami. Based on the mean of these distances, alternative anesthesia was carried out on 300 patients, and the success rate of the technique was evaluated.

Results

The mean vertical distance was 8.85±2.59 mm, and the mean horizontal distance was 14.68±1.44 mm. The vertical (P<0.001) and the horizontal (P<0.05) distances showed significant differences between the sex groups. The success rate of the IOR-guided technique was 97.3%.

Conclusion

IANB-based location of mandibular lingula showed a high success rate. From this study, we concluded that analysis of the anatomic locations for mandibular lingula and IOR-guided IANB are useful for restorative and surgical dental procedures of the mandibular molars.

Imaging study on relationship between the location of lingula and the Gonial angle in a Chinese population

PURPOSE

The purpose of this study was to investigate the Gonial angle in relation to the position of the lingula using computerized image analysis to guide the oral surgeons to prevent injury to the inferior alveolar nerve and peripheral blood vessels during surgery.

METHODS

We measured Gonial angle sizes of bilateral rami and the distances from the lingula tip to the mandibular notch (LN), the anterior (LA) and posterior (LP) margin of the mandibular ramus, the mandibular base (LB) and the occlusive plane (h) in 407 Chinese adults with CBCT.

RESULTS

In males, the mean distance of LN was 17.64 mm in the low Gonial angle group while 16.76 mm in the high Gonial angle group, which was significantly different between two groups (P < 0.001). The distance of LA in LGA group was obviously longer than that in HGA group (P < 0.001). The mean distance LP of men was 17.94 mm in LGA group while 16.9 mm in HGA group (P < 0.001). In females, the mean distance of LB in LGA group was 33.32 mm and 32.37 mm in HGA group (P < 0.01).

CONCLUSION

We discovered that the segment of the mandibular branch, between the mandibular lingula and the mandibular angle, was obviously smaller in the HGA group than that in the LGA group.

Location and shape of the mandibular lingula: Comparison of skeletal class I and class III patients using panoramic radiography and cone-beam computed tomography

PURPOSE

The aim of this study was to compare the location and the shape of the mandibular lingula in skeletal class I and III patients using panoramic radiography and cone-beam computed tomography.

MATERIALS AND METHODS

The sample group included 190 skeletal class I patients and 157 class III patients. The location of the lingula in relation to the deepest point of the coronoid notch was classified into 3 types using panoramic radiographs. The shapes of the lingulae were classified into nodular, triangular, truncated, or assimilated types using cone-beam computed tomographic images. The data were analyzed using the chi-square test.

RESULTS

The tips of the lingulae were at the same level as the coronoid notch in 75.3% of skeletal class I patients and above the coronoid notch in 66.6% of class III patients. The positions of the lingulae in relation to the deepest point of the coronoid notch showed statistically significant differences between class I and class III patients. The most common shape was nodular, and the least common was the assimilated shape. Although this trend was not statistically significant, the triangular shape was more frequently observed in class III patients than in class I patients.

CONCLUSION

The locations and the shapes of the mandibular lingulae were variable. Most of the lingulae were at the same level as the coronoid notch in skeletal class I patients and above the coronoid notch in skeletal class III patients. The nodular and assimilated-shaped lingulae were the most and the least prevalent, respectively.

Reevaluation of Mandibular Morphometry According to Age, Gender, and Side

AIM

This study aims to reevaluation the linear and angular measurements of mandibles with multidetector computed tomography (MDCT) that is a new method and used frequently in recent years.

MATERIALS AND METHODS

The archived MDCT images of 100 adult patients (age range, 15-74 years) without mandibular operation and trauma history were evaluated retrospectively. Mandibular ramus heights, maximal mandibular length, mandibular symphysis height, mandibular angles, and mandibular foramen distance measurements were performed on MDCT images. All measurement parameters were analyzed by gender, age groups, and sides.

RESULTS

Mandibular linear length measurements were higher in males than in females (P < 0.05). Only mandibular symphysis height was statistically significantly different in age groups (P < 0.05). The Angle 1 (gonial angle) was found to be significantly higher in females (P < 0.05). The Angle 3 (right condyle-gnathion-left condyle angle) was observed to be significantly higher in the 60+ age group (P < 0.05). The 3 of the mandibular foramen measurements (distance from the front edge, distance to gonion, and height of lingula) were found to be higher in males than in females (P < 0.05). There were no significant differences according to age groups in these measurements. The lengths of the mandibular canals were higher in males (44.72 mm) than in females (41.68 mm). There was no statistically significant difference was found between gender, age groups, and sides of mandibular canal length.

CONCLUSION

The MDCT was found to be a reliable method for the detection of mandibular morphometry when compared with the results of other radiographic images studies.

The variable position of the inferior alveolar nerve (IAN) in the mandibular ramus: a computed tomography (CT) study

INTRODUCTION

This study was designed to quantify the important anatomical landmarks and the path of the inferior alveolar nerve (IAN) within the human mandibular body and ramus, in particular with reference to the bilateral sagittal split osteotomy (BSSO).

MATERIALS AND METHODS

Four hundred and eleven CT scans were studied, 299 of these were involved in determining the position of lingula; and 230 were involved in determining the course of IAN in the mandibular molar region, namely from the mesial of the mandibular first molar to the distal of the mandibular second molar; 118 were involved with both measurements.

RESULTS

On average, the lingula was located 17.0 ± 2.2 mm from the external oblique ridge; 11.6 ± 2.0 mm from the internal oblique ridge; 17.2 ± 2.7 mm from the sigmoid notch; and 15.6 ± 1.9 mm from the posterior border of the mandible. The course of the IAN in the mandibular molar region was found to descend vertically from the distal of the mandibular second molar (7) to reach its lowest point between the first and second molars (6 and 7), and then ascend towards the mesial of the first molar (6). Horizontally, the IAN was found to traverse medially between the distal of the 7 and the middle of the 7, and then changes its path laterally towards the mesial of the 6.

CONCLUSION

Precise knowledge of the individual's position of the IAN will help surgical planning.

A Novel Method for Observation of the Mandibular Foramen: Application to a Better Understanding of Dental Anatomy

Cone-beam computed tomography gives us much useful morphological information about the mandibular bone. Many studies of the mandible include findings from this technique. However, there have been no endoscopic studies of the mandible. Sixteen sides of eight dry mandibles resected from cadavers (age range 38-83 years) were examined by endoscopy. The head of the endoscope was 2.0 mm in diameter. We examined the mandibular foramen, lingula, mylohyoid groove, and mandibular canal. The mylohyoid grooves showed variations such as double grooves and canals. The mandibular lingula was located superior or medial to the the mandibular foramen. In a single case, the medial wall inside the mandibular canal showed a porous surface. The retromolar canal was observed in three sides. None of the images in the present study have been seen in other studies. Observation of the retromolar canal from the mandibular canal in particular can help dental students as well as oral and maxillofacial surgeons to understand its morphology. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 300:1875-1880, 2017. © 2017 Wiley Periodicals, Inc.

Location, shape and anatomic relations of the mandibular foramen and the mandibular lingula: a contribution to surgical procedures in the ramus of the mandible

PURPOSE

The purpose of this study was to obtain morphological parameters of the mandibular foramen (MF) and the mandibular lingula (ML) as well as to use biometric data to locate these structures in the medial aspect of the mandibular ramus and to measure the angle that the inferior alveolar sulcus makes with the posterior margin of the ramus.

METHODS

The sample was composed of 30 dry human mandibles. The quantitative variables were the distances between the MF and the ML, as well as the distances between these structures and the margins of the mandibular ramus. The angle between the inferior alveolar sulcus and the posterior margin was also measured. The qualitative variables were the shape of the MF and the ML. All variables were analyzed using statistical softwares and the admitted level of statistical significance was 5 %.

RESULTS

The statistical analysis indicated a bilateral central positioning of the MF and the ML in relation to the medial surface of the mandibular ramus, however, with a more superior and posterior positioning when the relatives values-which also indicated an oval morphology of the MF and trapezoidal shape of the ML-were considered. The inferior alveolar sulcus was in an acute angle with the posterior margin of the ramus with a larger opening in the left side of the mandible-but equals, however, considering the margins of error.

CONCLUSIONS

With the data presented in this study, the surgeon will obtain quantitative and qualitative parameters that can be added to the surgical literature available, facilitating the identification and preservation of the anatomic structures in check, reducing, thus, the risk of iatrogenic injuries.

Morphological study of the lingula in adult human mandibles of Brazilians individuals and clinical implications

Objectives. The purpose of this research was to study, in macerated adult human mandibles, the height of the lingula and provide morphometric data for its location considering aspects such as shape of the lingula, gender, and race. Material and Methods. 132 macerated mandibles of Brazilian adult individuals, both sexes, Amerindian and Caucasian, were used. The distances: from mandibular notch to lingula; from anterior margin of ramus of mandible to lingula; from posterior margin of ramus of mandible to lingula; from mandibular base to lingula, and the height of lingula were obtained. To perform these measurements we used a digital caliper. The variables such as gender and race were analyzed. Results. The mean values found for the height of lingula and its location were determined according to the gender, race, and the lingula shape. Conclusion. This research provides additional data on height of the lingula and morphometric data for its location considering aspects such as shape of the lingula, gender, and race, information that had not been reported in the literature to date. We emphasize that a careful study considering gender and ethnic group makes procedures involving the region of lingula safer.

Cone beam computed tomographic analysis of the shape, height, and location of the mandibular lingula in a population of children

OBJECTIVES

This is the first study to identify and classify the different morphological shapes of the mandibular lingula (ML) in children using cone-beam computed tomography (CBCT).

MATERIAL AND METHODS

A retrospective study was performed to evaluate the shape, height, and location of the ML in relation to the surrounding structures using CBCT images of mandibles obtained from 269 children. The shape of the ML was classified into triangular, truncated, nodular, or assimilated types. The location was determined by five distances. The height of the lingula was also measured from the lingular tip to the mandibular foramen.

RESULTS

A nodular shape of the ML was most commonly found (48.3%, n = 260) followed by truncated (23.4%, n = 126), assimilated (14.4%, n = 78), and triangular (13.7%, n = 74). The mean distance of ML from the anterior and posterior borders of mandibular ramus was 13.3 ± 2.3 mm and 10.2 ± 1.6 mm, respectively. In the majority of the mandibles studied, the ML was located above the occlusal plane.

CONCLUSION

The present study provides new information to the literature concerning the shape, height, and location of the lingula in a Turkish pediatric population. This finding may assist clinicians to localize the lingula and avoid intraoperative complications.

Three-dimensional anatomic analysis of the lingula and mandibular foramen: a cone beam computed tomography study

PURPOSE

The authors analyzed the anatomic location differences of the mandibular foramen (MF) and lingula in a cone beam computed tomography study, aiming to obtain information that could be used when performing mandibular osteotomies and the inferior alveolar nerve block (IANB).

METHODS

Three-dimensional mandibular computed tomography images were reconstructed from data for 139 patients (278 sides) aged between 9 and 18 years (growth group, 27 patients) and aged 19 to 71 years (adult group, 112 patients).

RESULTS

In the adult group, positive correlations were seen between right and left measurements. In the growth group, there are significant differences in lingula-anterior and MF-posterior ramus measurements. In the adult group, there are significant differences between man and woman MF-gonion distance measurements. Differences were seen in edentulous and asymmetry patients.

CONCLUSIONS

The MF is an important anatomic landmark for ramus surgery and IANB. When applied to ramus operations and IANB, the anatomic data provided by this study may help surgeons gain more understanding of nerve position during surgery.

Anatomic study of the mandibular foramen, lingula and antilingula in dry mandibles, and its statistical relationship between the true lingula and the antilingula

The authors verified the anatomical location of the mandibular foramen, lingula and antilingula in dry mandibles, aiming to obtain information that could be used when performing mandibular osteotomies. Forty-four mandibles (88 sides) were evaluated. The distances were measured using a sliding calliper, with the mandibles fixed in a reproducible position. Results showed that the mandibular foramen is on average 5.82 mm below the lingula. Regarding the statistical comparison between the mandibular foramen entrance and the antilingula position, there is no correlation between the position of those two structures in the studied sample. The mandibular foramen is slightly posterior in relation to the centre of the ramus. The lingula is an important anatomic landmark for ramus surgery, and for determining the distance to the mandibular foramen entrance. The use of the antilingula as a landmark for the position of the vertical ramus osteotomy is not recommended.