Evaluation of the relationship between the maxillary posterior teeth and the sinus floor using cone-beam computed tomography

Anatomic relationship between the root apex of maxillary molars and maxillary sinus in the presence of antagonist teeth: A Kwak's method with divisions

OBJECTIVE

The purpose of the study was to evaluate the proximity between the root apices of maxillary molars and maxillary sinus floor using cone-beam computed tomography (CBCT) in the southern Turkish subpopulation.

DESIGN

For the study, 246 CBCT images were analyzed. The absence of antagonist teeth was excluded. Kwak's types III and V were detailed with three divisions. Division M; the penetration of the mesial root only, Division D; the penetration of the distal root only, and Division MD; the penetration of both buccal roots. The distance between the maxillary sinus and the root apices was measured. Student's t-test, one-way ANOVA, and chi-square were used for statistical analysis.

RESULTS

The penetration of maxillary molars was 24.40%. The highest prevalence belonging to Type I. Division MD was 44.35% for Type III and 40.42% for Type V. Division M was higher than Division D. The distances between the sinus and root apices were 1.35-2.41 mm in Type I. The distance decreased with age (p < 0.05).

CONCLUSION

Both buccal root penetration into the sinus was higher than the single root penetration. The distance of the second molar root apices to the sinus was closer than the first molar. One-quarter of the first and second molars were inside the sinus. A greater likelihood of penetration of the root apices into the sinus with increased age.

Panoramic Radiography in the Evaluation of the Relationship of Maxillary Molar Teeth and Maxillary Sinuses on the Deep Learning Models Improved with the Findings Obtained by Cone Beam Computed Tomography

BACKGROUND

Panoramic radiography (PR) is available to determine the contact relationship between maxillary molar teeth (MMT) and the maxillary sinus floor (MSF). However, as PRs do not provide clear and detailed anatomical information, advanced imaging methods can be used.

AIM

The aim of this study was to evaluate the diagnostic performance of deep learning (DL) applications that assess the relationship of the MSF to the first maxillary molar teeth (fMMT) and second maxillary molar teeth (sMMT) on PRs with data confirmed by cone beam computed tomography (CBCT).

METHODS

A total of 2162 fMMT and sMMT were included in this retrospective study. The contact relationship of teeth with MSF was compared among DL methods.

RESULTS

DL methods, such as GoogLeNet, VGG16, VGG19, DarkNet19, and DarkNet53, were used to evaluate the contact relationship between MMT and MSF, and 85.89% accuracy was achieved by majority voting. In addition, 88.72%, 81.19%, 89.39%, and 83.14% accuracy rates were obtained in right fMMT, right sMMT, left fMMT, and left sMMT, respectively.

CONCLUSION

DL models showed high accuracy values in detecting the relationship of fMMT and sMMT with MSF.

Anatomical Possibilities of the Alveolar Bone at the Upper Second Premolar Level

Background and Objectives: The upper posterior teeth are typically regarded as being exclusively inferior to the maxillary sinus (MS). The expansion of the nasal fossa above the maxillary alveolar base (MAB) needs better investigation. The hypothesis was raised that the MAB in the upper premolar region, which is usually addressed by surgeons for the elevation of the antral floor, is not exclusively beneath the MS. Therefore, we aimed to document the possible upper relations of the MAB as antral, nasal, or both. Materials and Methods: A total of 145 CBCT scans were used to study four types of MAB: type 1-antral; type 2-antral with a palatal recess; type 3-antral and nasal; type 4-nasal. In type 2, the orthoradial width of the alveolar bone, the rectilinear width of the antral floor, and the maximum depth of the palatal recess were measured. For type 3, the MAB width and the straight widths of the antral and nasal segments of the MAB were measured. Results: Type 1 was found in 67.24%, type 2 in 13.45%, type 3 in 16.21%, and type 4 in 3.1% of the 290 MSs investigated. Palatal recesses were found in 11.72% of the MSs on the right side and 15.17% of the MSs on the left side. Types 1 and 2 exhibited strongly statistically significant bilateral symmetry (Pearson's Chi2 = 86.42, p < 0.001). Type 3 correlated equally with contralateral types 1 and 3. The bilateral symmetry for types 1-3 was stronger in the males (Pearson's Chi2 = 47.83, p < 0.001) than in the females (Pearson's Chi2 = 56.96, p < 0.001). There were no statistically significant associations between sex and the unilateral anatomical type. Conclusions: The MAB in the upper second premolar area should not be considered to be exclusively antral during surgeries or in anatomical teaching.

Evaluation of Dimensional Changes in Maxillary and Frontal Sinus in Adult Patients With Anterior Open Bite and Normal Overbite: A Retrospective Cone Beam Computed Tomography (CBCT) Study

INTRODUCTION

An anterior open bite is a form of vertical discrepancy that presents as a lack of contact between maxillary and mandibular segments. The treatment modalities usually involve either intrusion of posterior teeth or extrusion of anterior or a combination of both. The anatomical relationship between the apex of the maxillary molar roots to the inferior wall of the maxillary sinus floor is crucial in planning posterior intrusion. The paranasal sinuses influence the growth of the facial structures that eventually get altered in various malocclusions. Studies have proven that the height of the sinus gets modified in anterior open bite owing to pneumatization. This study aims to evaluate the distance from the root apex of maxillary first molars (mesiobuccal, distobuccal, and palatal roots) to the maxillary sinus floor to evaluate the significance of the vertical pneumatization of the sinus on planning for true intrusion in anterior open bite and to assess the correlation between frontal and maxillary sinuses in an anterior open bite.

METHODS

This retrospective study evaluated 30 pre-treatment cone beam computed tomographies (CBCTs) of patients out of which 15 were with anterior open bite and 15 with ideal overbite. Linear measurements were carried out using care stream software in CBCTs.

RESULTS

There was a significant correlation between the distance of the palatal root and the distobuccal root of the maxillary first molar to the maxillary sinus floor bilaterally in the anterior open bite (p<0.04). A significant moderate positive correlation of the maxillary and frontal sinus height in anterior open bite (p<0.006). A significant moderate negative correlation between the distance from the palatal root to the maxillary sinus floor and maxillary sinus height in anterior open bite (p<0.001).

CONCLUSION

Vertical pneumatisation of the maxillary sinus has caused a significant negative correlation between the apex of the palatal root of the maxillary first molar tooth and the maxillary sinus floor in the anterior open bite. The palatal root being the closest to the sinus floor, and the distobuccal root being second nearest. There is a significant correlation between the height of the sinuses in the anterior open bite.

Characteristics of CBCT versus panoramic signs of the surrounding bone of molar root protrusions into the maxillary sinus

The study aimed to (a) investigate the amount and characteristics of the surrounding bone of protruded molar roots into the maxillary sinus using cone-beam computed tomography (CBCT) and (b) assess the correlation between the amount of bone with panoramic high-risk signs. Radiographs of 408 roots protruding beyond the sinus floor were evaluated. Axial CBCT images were used to investigate then classify eight characteristics of surrounding bone: no bone; bone < half the root girth in the proximal or buccal-palatal aspect; bone covering half the root girth in the proximal or buccal-palatal aspect; bone > half the root girth in the proximal or buccal-palatal aspect; and, complete bone. These were then grouped into four degrees of bone support: no bone; bone ≤ half the root girth; bone > half the root girth; and, complete bone. Panoramic signs were subclassified as: projection of root; interruption of the sinus floor; darkening of the root; upward curving of the sinus floor; absence of periodontal ligament space; and, absence of the lamina dura. Correlation between the degree of bone and the panoramic signs was evaluated using the Chi-square or Fisher's exact tests. Positive and negative predictive values, sensitivity, specificity, accuracy, and receiver operating characteristic analysis were calculated. Complete bone support was the most common. 'Projection of root' had a high negative predictive value and sensitivity. 'Absence of the periodontal ligament space and lamina dura' had a high positive predictive value, specificity, accuracy, and area under the curve. These two signs were significantly correlated with the degree of bone support.

Relationship of maxillary third molar root to the maxillary sinus wall: A cone-beam computed tomography (CBCT) based study

Background

The relationship of the root of the maxillary third molars and the maxillary sinus (MS) is an important predictor of the anticipated difficulty in extraction. The aim of this study was to assess the location of maxillary third molars to the inferior wall of the MS in a sample of Pakistani population evaluated using cone-beam computed tomography (CBCT) imaging and to assess if age or gender has any influence on third molar to MS distance.

Methods

The CBCT scans of adult patients, carried out keeping image volume at 8 cm×8 cm, and the voxel size 0.2 and 0.1 mm. Images retrieved from the hospital database were included in the study. The relationship of root apices of maxillary third molar with the MS was assessed according to the vertical, horizontal and Winter's classification. Descriptive statistics, t test and chi-square test of association were applied.

Results

CBCT scans of 93 patients, 56 males and 37 females were evaluated. The mean age was 41.12±17.13 years. The mean distance of third molar roots to the MS wall was 2.38±1.54 mm for males and 1.86±1.04 mm for females, on the left and 2.67±1.81 mm for males and 2.58±1.54 mm in females, on the right side. Independent sample t test showed that there was no significant difference for third molar to sinus wall distance in the two genders. No significant difference was found between the two sides.

Conclusion

In a sub-population of Pakistani adults, the mean distance between the roots of the upper third molar and MS wall is around 2 mm. Only 5% males and 8% females had their upper third molars roots protruding into the MS.

Anatomical Evaluation of Posterior Maxillary Roots in Relation to the Maxillary Sinus Floor in a Saudi Sub-Population: A Cross-Sectional Cone-Beam Computed Tomography Study

To evaluate the mean distance and differences between posterior maxillary teeth and maxillary sinus floor (MSF) concerning the age and gender of the patients, a total of 124 maxillary sinuses and 496 posterior maxillary teeth were randomly selected in 62 cone-beam computed tomography (CBCT) images. Mean distances between posterior maxillary roots (PMRs) from different teeth and the MSF were measured using a calibrated tool in the software. Other relations regarding the gender and age of the patients were determined. The mean root-MSF distances in the right and left first premolars were more significant compared to the second premolars. No significant relation was found between the apices of the right and left first and second molar roots and the floor of the maxillary sinus concerning gender. A statistically significant relation was found between the apices of the buccal root of the right first premolar, right and left first and second molars and floor of the maxillary sinus concerning the age group 21-40 years (p-value = 0.009). This study showed that the second molar mesiobuccal root apex is frequently related to the sinus floor. Differences were reported concerning age, concerning the distance between posterior maxillary teeth and the maxillary sinus floor. CBCT technology helped provide the clinical proximity between the MSF and the posterior teeth root apices during the treatment planning.

Treatment effects after maxillary total arch distalization using a modified C-palatal plate in patients with Class II malocclusion with sinus pneumatization

INTRODUCTION

The purpose of this study was to evaluate the treatment effects after molar distalization using modified C-palatal plates in patients with Class II malocclusion with maxillary sinus pneumatization.

METHODS

This study consisted of 70 lateral cephalograms derived from cone-beam computerized tomography images of 35 patients with Class II malocclusion (mean age 22.3 ± 7.4 years) who had undergone bilateral total arch distalization of the maxillary dentition using modified C-palatal plates. The samples were divided into 2 groups according to sinus pneumatization; group 1 (n = 40), cephalograms with sinus pneumatization and group 2 (n = 30) cephalograms without sinus pneumatization. Paired t tests and independent-sample t tests were used to compare the changes in each group and between groups.

RESULTS

The distal movement of the maxillary first molars was 4.3 mm for group 1 and 3.5 mm for group 2, with the intrusion of 1.4 mm and 2.5 mm, respectively. There was no statistically significant difference between the 2 groups. Group 1 showed 3.5° of distal tipping of the maxillary second molars, which was significantly greater than the 0.2° in group 2 (P <0.05). The total treatment period, including distalization, was 2.2 years for group 1 and 1.9 years for group 2, but the difference was not significant.

CONCLUSIONS

There was no significant difference in the amount of distal movement and intrusion of the maxillary first molars between groups 1 and 2. Therefore, these results suggest that regardless of sinus pneumatization, molar distalization using temporary skeletal anchorage devices in Class II patients can be performed as a nonextraction treatment.

Assessment of the Relationship between Maxillary Posterior Teeth and Maxillary Sinus Using Cone-Beam Computed Tomography

Introduction

Because of the close contact between maxillary sinus and maxillary posterior teeth, procedural errors such as perforation of the sinus may occur during surgical intervention resulting in oroantral communication, which if not corrected, would develop into a fistula. The aim of this study was to evaluate the relationship between maxillary posterior teeth and maxillary sinus floor in a population of the western area of Saudi Arabia, and if age, gender, and size may affect such distance.

Materials and Methods

This retrospective study evaluated 539 cone-beam computed tomography (CBCT) radiographs of patients over 20 years of age. Patients were divided into four groups according to age: group I (20–30 years), group II (31–40 years), group III (41–50 years), and group IV (more than 50 years). From coronal and sagittal images of CBCT, the vertical distance between the posterior maxillary root and the maxillary sinus was measured and classified according to its proximity to the maxillary sinus.

Results

Gender and size did not significantly affect the distance between maxillary posterior root and maxillary sinus. However, there was a significant increase in this distance with increased age. Mesiobuccal root of the second molar was the nearest root to the maxillary sinus (0.8 ± 1.62, p < 0.001), while the buccal root of the first premolar was the farthest root (5.39 ± 3.26, p < 0.001).

Conclusion

Regarding the population of this study, the buccal roots of the second molars are the closest to the sinus floor. Complications associated with maxillary molar extraction and implantation are greater at a younger age. Because the distance between posterior maxillary teeth and maxillary sinus was mostly type 1 (0–2 mm), clinicians are advised to perform CBCT to get a better understanding of the relationship between maxillary posterior roots and maxillary sinus before surgical intervention.

Maragathavalli. Assessment of the vertical relationship between the maxillary posterior teeth and the maxillary antral floor in a South Indian population using Cone Beam Computed Tomography- A radiographic observational study

Introduction and Aim: Maxillary sinus, also known as the Antrum of Highmore, is said to be one of the largest pyramidal shaped paranasal sinuses that begins at the 10th week of intrauterine development and undergoes pneumatisation. The root apices of the maxillary posterior teeth have a proximity to the antral floor, so a thorough understanding of this anatomical relationship is very essential as it can have an important influence during dental procedures such as implant planning, extractions, and certain other oral and maxillofacial surgeries. The aim of this study was to assess the vertical relationship between the posterior teeth in the maxillary arch with the floor of the maxillary antrum, using Cone Beam Computed Tomography (CBCT) in a South Indian population.   Materials and Methods: This was a retrospective analysis of 50 right or left maxillary sinuses in panorama and tangential sections by tracing the outline forms of the maxillary antral floor and also measuring its vertical distance from maxillary posterior root apices.   Results: Four types of relationship patterns were observed between the maxillary antral floor and root apices of the maxillary posteriors. The root apices of the maxillary second molar were found to be in close proximity with the maxillary sinus (2.27mm) and similar observation was found in the left side with the left second molar to be in close proximity to the sinus (2.04 mm).   Conclusion: The assessment of this vertical relationship is very important during extractions, implant planning or during any other surgeries in the maxillofacial region.

Three-dimensional assessment of the favorability of maxillary posterior teeth intrusion in different skeletal classes limited by the vertical relationship with the maxillary sinus floor

Background

Understanding the anatomical relationship between the maxillary sinus floor (MSF) and the posterior maxillary teeth (PMT) is important when planning the orthodontic intrusion of the posterior teeth. This study aimed to determine the vertical relationship between posterior maxillary teeth and maxillary sinus floor in different skeletal classes in the Chinese adult population.

Methods

This is a retrospective cross-sectional study involved cone beam computed tomography images of 298 adult patients (145 males and 153 females) between 20 and 45 years old. The sample was categorized according to A point, Nasion, B point (ANB) angle into 102 Class I, 102 Class II, and 94 Class III malocclusion. Non-parametric Wilcoxon Mann–Whitney U and Kruskal–Wallis tests were used to compare the studied groups. The Intra-class Correlation Coefficient (ICC) was used to assess the intra- and inter-observer reliability analysis.

Results

Overall, there was a statistically significant difference in the mean distance between both genders (P < 0.001). The measured distance increased with age in all posterior tooth roots (P < 0.001). The root apex in the sagittal view appeared to be closer to the maxillary sinus than in the coronal view; 2.2 ± 4.3 and 3.1 ± 5.5 mm, respectively. The most frequent root scores were Type 1 and Type 2P. In both sagittal and coronal views, Class I demonstrated a higher Type 2P prevalence, whereas Class III showed a lower prevalence. The second molars’ mesiobuccal root had the largest number of penetration in the three examined skeletal classes.

Conclusions

Maxillary molars of Class I malocclusion with the majority of Type 2P root-sinus relationship have the highest possible risk of root resorption during molar intrusion due to cortical bone encroachment, while Class III malocclusion showed the least possible risk.

Supplementary information

The online version contains supplementary material available at 10.1186/s13005-022-00316-3.

Three-dimensional quantification of the relationship between the upper first molar and maxillary sinus

Objectives

The present study aims to describe the relationship between upper first molar roots and maxillary sinus, for the first time with a truly three‐dimensional approach.

Methods

From a retrospective cone‐beam computed tomography (CBCT) sample of the upper jaw, a total of 105 upper first molars in contact with maxillary sinus from 74 patients (male 24, female 50, mean age 42) were included in the present study. Segmentation of the upper first molar and maxillary sinus in CBCT was performed utilizing a semiautomatic livewire segmentation tool in MeVisLab v.3.1. The segmentations were analyzed in 3‐matic Medical 20.0 for root volume and the contact area between upper first molar roots and maxillary sinus. Analysis of variance test was applied to detect statistically significant differences between the roots.

Results

The palatal root had the largest contact area with maxillary sinus 27.8 ± 21.4 mm² (20% of the root area) followed by the mesiobuccal 20.5 ± 17.9 mm² (17% of the root area) and distobuccal root 13.7 ± 12 mm² (14% of the root area). A significant difference in the contact area of the different roots of the upper first molar was seen.

Conclusions

This study showed that 70% of the upper first molars were in contact with the maxillary sinus. The palatal root had on average a fifth of its root surface in contact with the sinus, while for mesiobuccal this was a sixth of its root surface and distobuccal roots this was somewhat less. The true 3D relationship could help to better understand maxillary anatomy in relation to occurring pathologies and treatment planning in this area.

Relationship of the maxillary posterior teeth and maxillary sinus floor in different skeletal growth patterns: A cone-beam computed tomographic study of 1600 roots

Purpose

This study evaluated the distance from the posterior root apices to the maxillary sinus floor (MSF) and the frequency of roots touching or protruding through the MSF using cone-beam computed tomography (CBCT).

Materials and Methods

This study included 100 subjects divided into different vertical and anteroposterior skeletal growth patterns. On CBCT images, the distance from the posterior root apices to MSF was measured and the frequency of roots touching or protruding through the MSF was evaluated using NNT software (version 5.3.0.0; ImageWorks, Elmsford, NY, USA).

Results

No statistically significant differences were found in the distance from the posterior root apices to the MSF among vertical skeletal groups (P>0.05). The palatal roots of the first molar and the palatal, mesio-buccal and disto-buccal roots of the second molars had significantly less distance from MSF in skeletal class II than in class III (P<0.05). The high-angle group had the highest frequencies of roots touching or protruding into the maxillary sinus (49.8%); the lowest proportion of these roots was found in skeletal class III (28.3%) and the highest proportion in class II (50.3%). Males had shorter distances from the posterior root apices to the MSF and higher frequencies of roots protruding through or touching the MSF than females.

Conclusion

Anteroposterior skeletal growth patterns and sex affected the distances from the maxillary posterior roots to the MSF. The frequency of roots protruding into or touching the sinus was affected by both vertical and anteroposterior skeletal groups and sex. These findings have implications for dental practice.

CBCT evaluation of root canal morphology and anatomical relationship of root of maxillary second premolar to maxillary sinus in a western Chinese population

BACKGROUND

To evaluate the root anatomy, root canal morphology and the anatomical relationship between the roots and maxillary sinus of maxillary second premolars by CBCT in a western Chinese population.

METHODS

A total of 1118 CBCT scans of the maxillary second premolars were collected from West China Hospital of Stomatology, Sichuan University. Information below were measured on axial, coronal and sagittal sections, recorded and evaluated properly: the number of roots and canals, the morphology of canal system classified by Vertucci standard, the inter-orifice distance of canal orifices, the curvature of each canal and the distance from root tip to maxillary sinus floor.

RESULTS

Among the 1118 teeth, 94.2% (1053) are single-rooted and 55.1% (616) have one canal. Type I (55.1%) is the commonest root canal morphology followed by Type II (31.9%). The mean inter-orifice distance (IOD) for multi-canal teeth ranging from 2.72 ± 0.32 to 3.41 ± 0.11 mm. Of 1622 canals, 38.8% (630) curvature are mesiodistal and 30.9% (501) are straight canals. The distance from root tip to maxillary sinus floor increased with age and the mean distance of single-rooted ones is 2.47 ± 3.45 mm.

CONCLUSIONS

All kinds of canal morphology category can be detected in maxillary second premolars. The IOD might be a predictable factor for root canal morphology. Roots of maxillary second premolars are related to maxillary sinus which should be treated carefully.

Assessment of the relationship between the maxillary sinus and the canine root tip using cone beam computed tomography

BACKGROUND

The purpose of the present study is to investigate the relationship between the maxillary sinus and the canine root apices in cone beam computed tomographic images (CBCT) and to assess the amount of extension of the maxillary sinus to the anterior region of the jaw in different sexes and age groups.

METHODS

CBCT of 300 individuals (154 males and 146 females) over 20 years (with a mean age of 35.12 ± 8.40 years) were evaluated. The subjects were categorized into three age groups (20-30, 30-40, and 40-50 years). When the maxillary sinus extended to the canine area, the vertical distance between them was measured, and their relationship was classified into three types: I (more than 2 mm distance), II (less than 2 mm distance or in-contact), and III (interlock).

RESULTS

413 out of 600 maxillary sinuses (68.8%) were extended into the canine area or beyond. Among them, 15 maxillary sinuses pneumatized into the incisor area (2.5%). The prevalence of the maxillary sinuses extended to the anterior region of the jaw was not significantly different between genders. However, it was significantly less frequent in the older age group and more frequent on the left side. In addition, the mean amount of anterior extension of the maxillary sinus (mm) was significantly lower in the older age group. Type I was the most frequent vertical relationship between the maxillary sinuses and canine apices with no significant difference in gender, side, and age groups.

CONCLUSIONS

In most cases, the maxillary sinus extended to the canine area and sometimes reached the incisor region. This necessitates paying more attention to the maxillary anterior sextant during surgical procedures.

CBCT-based assessment of the anatomic relationship between maxillary sinus and upper teeth

Objectives

To describe the relationship between maxillary sinus (MS) and upper teeth based on cone beam computed tomographic scans (CBCT).

Materials and methods

Based on CBCT maxillary imaging data of 147 patients, distance between MS and apices of canines and posterior maxillary teeth were assessed. Distances between tooth roots and sinus were classified into three groups: distant (>2 mm), close (<2 mm) or in contact with MS. Teeth with apical lesions and uncommon root configurations were excluded.

Results

In total, 1075 teeth of maxillary canines, upper premolars and upper molars were included in this study. Teeth most often in contact with MS were the second (89%) and first (81%) maxillary molar without any significant difference (p = 0.19). Roots most often in contact with MS were the mesiobuccal and distobuccal root of the second molar (85% and 76%; p = <0.01) followed by the palatal root of the first molar (73%). A fifth of the upper canines are situated less than 2 mm from MS.

Conclusions

More than four out of five upper molars (first and second) are in a close relationship to the MS. Knowledge of the anatomical relationship between posterior maxillary teeth and the MS is important for diagnosis and treatment in this area.

Comparison of panoramic radiography and cone-beam computed tomography for assessing radiographic signs indicating root protrusion into the maxillary sinus

Purpose

This study investigated correlations between findings on panoramic radiographs and cone-beam computed tomography (CBCT) to assess the relationship between the maxillary sinus floor and the roots of maxillary posterior teeth. In addition, radiographic signs indicating actual root protrusion into the maxillary sinus were evaluated on panoramic radiographs.

Materials and Methods

Paired panoramic radiographs and CBCT images from 305 subjects were analyzed. This analysis classified 2,440 maxillary premolars and molars according to their relationship with the maxillary sinus floor on panoramic radiographs and CBCT images. In addition, interruption of the sinus floor was examined on panoramic radiographs.

Results

Root protrusion into the maxillary sinus occurred most frequently in the mesiobuccal roots of the second molars. The classification according to panoramic radiographs and CBCT images was the same in more than 90% of cases when there was no contact between the root apex and the sinus floor. When the panoramic radiograph showed root protrusion into the sinus, the CBCT images showed the same classification in 67.5% of second molars, 48.8% of first molars, and 53.3% of second premolars. There was a statistically significant relationship between interruption of the sinus floor on panoramic radiographs and root protrusion into the sinus on CBCT images.

Conclusion

The presence of root protrusion into the sinus on panoramic radiographs demonstrated a moderate ability to predict root protrusion into the maxillary sinus. Interruption of the maxillary sinus floor could be considered an indicator of actual root protrusion into the maxillary sinus.

Topographic relationship between maxillary sinus and roots of posterior teeth: a cone beam tomographic analysis

Purpose:

The objective of the research was to determine the relationship between root apices and maxillary sinus wall, and to analyze pulpoapical conditions of 2nd premolars, 1st molars, 2nd molars, 3rd molars using cone beam computerized tomography (CBCT).

Materials and methods:

This study was conducted on a retrospective manner of CBCT images of 1000 maxillary sinus with 500 subjects, who visited the Department of Dento-Maxillofacial Radiology. The association of each teeth with sinus floor and pulpoapical status were categorized. The association among gender, age, lateralization of sinus cavity were evaluated.

Results:

A total of 602 second premolars, 500 first molars, 623 second molars, 347 third molars were evaluated. There were no significant differences between pulpoapical condition of teeth and gender or left and right sides (p=0.065, p=0.072). There were significant associations between pulpoapical condition of all teeth and age (p=0.023), and the relationship of each root with maxillary sinus and age (p=0.037). There was significant association between vertical position and right/left sides in second and third molars (p=0.033).

Conclusion:

Age seems to have relationship with periapical condition of teeth, and the association of root with the sinus cavity.

Evaluation of the Relationship Between Maxillary Sinus Wall and Maxillary Canines and Posterior Teeth Using Cone-Beam Computed Tomography

Background

The proximity between the maxillary sinus and dental roots may impede orthodontic tooth movement. This study aimed to explore the relationship between the maxillary sinus wall (MSW) and maxillary canines and posterior teeth using cone-beam computed tomography (CBCT).

Material/Methods

CBCT images (317) were examined for whether the mesial, distal, buccal, and palatal surfaces of the examined root contacted the MSW, and the contact distance of each root surface with the MSW was measured. The effects of age and sex were analyzed using logistic regression and linear regression analyses.

Results

The highest contact ratios with the MSW (ranging from 62.0% to 73.2%) were observed at the palatal root surfaces of the first molar mesiobuccal and distobuccal roots (1M MB and DB), the buccal root surface of the first molar palatal roots (1M P), and the mesial and buccal root surfaces of the second molars (2M), followed by the distal root surface of the second premolars (2PM) and the mesial root surfaces of the 1M MB and P (ranging from 49.2% to 59.3%). At these root surfaces, the contact ratios decreased with age (P<0.05), but the lowest still reached a range of 29.4% to 57.9% in the 30- to 47-year-old group.

Conclusions

The 2PM distal root surface, the 1M MB mesial and palatal root surfaces, the 1M DB palatal root surface, and the 1M P and 2M mesial and buccal root surfaces most frequently contacted the MSW. Clinicians should observe the contact of root surfaces with the MSW, even in aged patients.

Determination of alveolar bone height according to the relationship between molar teeth and maxillary sinus

PURPOSE

This study aims to analyze alveolar bone height (ABH) in the maxillary molar area according to the anatomical relationship between maxillary sinus and maxillary molar teeth via cone beam computed tomography images.

METHODS

In 330 patients, 660 maxillary first molar (M1) and 648 maxillary second molar (M2) were evaluated. ABH measurements were made as to the shortest distance between the furcation midpoints of maxillary molars and the lowest point of the sinus floor. After the measurement, the positions of the maxillary molar teeth relative to the maxillary sinus were classified into four categories as type 1, 2, 3, and 4.

RESULTS

ABH measurements in males were significantly higher than females (p < 0.05), but there were no differences between sides (p > 0.05). There were significant differences between types of both M1 and M2 for ABH, and the longest ABH was measured in type 1 (p < 0.05). Type 3 was the most common among 1308 maxillary molars teeth followed by type 1, type 2, and type 4.

CONCLUSION

Determination of the relationship between maxillary molar teeth and the maxillary sinus and analysis of ABH according to this relationship may help plan endodontic treatment, apical surgery, and immediate implant therapy and prevent their complications.

A cone-beam computed tomographic assessment of the proximity of the maxillary canine and posterior teeth to the maxillary sinus floor: Lessons from 4778 roots

INTRODUCTION

When tooth roots protrude into the maxillary sinus, apical root resorption and tipping may occur during horizontal tooth movement across the sinus floor. Three-dimensional cone-beam computed tomography (CBCT) images may provide detailed information without distortion and overlap. We evaluated the relationships between the maxillary tooth root apices and the maxillary sinus floor using CBCT.

METHODS

We evaluated 4778 roots from 76 men (aged 27.6 ± 10.4 [mean ± standard deviation] years; range, 18-69 years), and 225 women (aged 30.4 ± 12.0 years; range, 18-68 years). The positional relationships between the maxillary tooth root apices, including the canine, premolar (first and/or second), and molar (first and/or second), and the inferior wall of the maxillary sinus were comprehensively evaluated on 2 cross-sectional CBCT images (ie, the sagittal and coronal planes). These distances were measured in both images simultaneously.

RESULTS

The sagittal plane distances were significantly larger than coronal plane distances, except for the distobuccal root of the first molar. Pearson correlation test revealed a significant negative correlation between the distance and the patient's age.

CONCLUSIONS

Our study provides valuable information for planning orthodontic tooth movement through the maxillary sinus, which may help to predict the occurrence and severity of root resorption.

Odontogenic infection as a predisposing factor for pathologic disorder development in maxillary sinus

OBJECTIVE

To investigate an association between odontogenic infections (OI) and maxillary sinuses pathologic disorder (MSPD). The distance between the sinus floor and the root apex of upper posterior teeth was also assessed.

METHODS

Out of 4,402 cone beam computed tomography scans, 230 were selected, and 431 teeth were evaluated regarding the presence of OI: bone loss with furcation involvement, periapical and endodontic-periodontal lesions. The maxillary sinuses were assessed regarding the presence of MSPD, which was considered as mucosal thickening, opacification of the sinus and mucous retention cyst.

RESULTS

There was a significant association between OI and MSPD (p < .001). Periodontal bone loss with furcation involvement, periapical lesions and endodontic-periodontal lesions increased the risk of opacification of the sinuses by 11.6, 34.1 and 228.8 times, respectively. The frequency of the different types of MSP showed not to be associated with a group of teeth or dental root. Conversely, the presence of MSP was associated with a significant shorter distance between the palatine root apex and the sinus floor (p < .001).

CONCLUSION

There is a relationship between infectious process of teeth and MSPD. The proximity between the apex of palatine roots and the maxillary sinus floor showed to be a predisposing factor for MSPD.

Cone-beam Computed Tomographic Analysis to Detect the Association between Primary and Secondary Endodontic Infections and Mucosal Thickness of Maxillary Sinus

INTRODUCTION

This retrospective study used cone-beam computed tomographic (CBCT) imaging to evaluate the differences in the mucosal thickness of the Schneiderian membrane in primary and secondary endodontic lesions.

METHODS

A total of 121 CBCT scans were analyzed. Clinical features such as sex, age, size and volume of the periapical lesion, dimension of the bone, morphology, and relationship between the roots and the mucosal thickness were recorded and analyzed in primary and secondary endodontic lesions in CBCT sagittal and coronal planes. Data were analyzed using the chi-square test, the Mann-Whitney U test, and multiple logistic regression (P < .05).

RESULTS

Statistical analysis revealed no significant differences in membrane thickness between the primary and secondary lesions in the sagittal and coronal planes (P = .08 and .06). Differences between age groups were statistically significant in both groups (P < .05). The volume of the periapical lesions of the secondary endodontic lesions were statistically greater than that of the primary lesions (P < .05). Mucosal thickness prevalence increased when the volume of the lesion was greater, and the bone dimension was narrower in maxillary second premolars and first and second molars. Teeth with 2 or more affected roots were directly related to increased sinus mucosa thickening.

CONCLUSIONS

CBCT images showed no differences in mucosal thickening between primary and secondary endodontic lesions.

Associations between Periapical Health of Maxillary Molars and Mucosal Thickening of Maxillary Sinuses in Cone-beam Computed Tomographic Images: A Retrospective Study

INTRODUCTION

This retrospective study aimed to assess the radiologic characteristics of the possible associations between mucosal thickening of the maxillary sinuses (MSs) and periodontal and anatomic conditions of healthy and diseased maxillary teeth.

METHODS

The periapical health of the maxillary molars in cone-beam computed tomographic (CBCT) images from 50 patients (mean age = 40.60±14.59 years) was evaluated using the CBCT-periapical index. Anatomic associations between maxillary molars and the inferior wall of the MSs and periodontal bone loss and its relation to MS pathology were assessed. The possible effects of these conditions on mucosal thickening of MSs were analyzed. Kruskal-Wallis, Mann-Whitney U, chi-square, and logistic regression (for relative risk) tests were used for statistical analysis.

RESULTS

CBCT-periapical index 4 was the most frequently encountered apical periodontitis (AP) lesion. The risk for pathologic changes in the MSs was significantly higher in the presence of AP (P < .001). This risk was 62.364 times greater than that in areas of MSs adjacent to healthy teeth of the same patient (95% confidence interval, 7.968-488.14). Thicker MS mucosae were detected when the molar roots with AP were closer to the MSs (P < .004). No statistically significant difference was found between periodontal status and MS pathology.

CONCLUSIONS

The findings of this study showed that MSs were affected by the endodontic health of adjacent molar teeth. Dental and medical practitioners should take into consideration the possible odontogenic causes while examining pathologic changes in the MS.

Anatomical analysis of periapical bone of maxillary posterior teeth: a cone beam computed tomography study

Objectives

To investigate the periapical bone thicknesses of maxillary posterior teeth at the preferred level for root resection (3 mm apical to the root end) and to determine vertical distances from apex to maxillary sinus floor (MSF) using cone beam computed tomography (CBCT) scans.

Methods

CBCT scans were collected from 341 subjects (2389 teeth). Associations of bone thicknesses and vertical distances with age and sex were determined by one-way analysis of variance.

Results

At the level of root-end resection, buccal bone was the thickest over the mesiobuccal roots of second molars (mean, 2.99 mm) and thinnest over the double-root first premolars (mean, 0.29 mm). In maxillary posterior teeth, thicker buccal bone was found in men than in women. The mesiobuccal roots of second molars were nearest to the MSF (mean, 1.33 mm), and were also most frequently extended into the sinus cavity (15.81%). Subjects more than 40 years of age had larger vertical distances from root apices to MSF in the molar region, compared with younger subjects.

Conclusions

Generally, periapical bone was thicker in men, and root apices were located nearer to the MSF in younger subjects. Age and sex should be considered before endodontic microsurgery.

Evaluation of the relationship between maxillary posterior teeth and the maxillary sinus floor using cone-beam computed tomography

BACKGROUND

Maxillary posterior teeth have close anatomical proximity to the maxillary sinus floor (MSF), and the race, gender, age, side and presence/absence of adjacent teeth may influence the mean distances between the root apices and the MSF. This study aimed to evaluate both the relationship between the maxillary posterior teeth and MSF, and the influence of adjacent teeth loss on the distance between the maxillary posterior roots and MSF.

METHODS

Cone-beam computed tomography images were collected from 1011 Chinese patients. The relationship between the maxillary posterior teeth and the MSF was divided into three types: Type OS (the root apex extending below/outside the MSF), Type CO (the root apex contacting with the MSF), Type IS (the root apex extending above/inside the MSF). The minimum vertical distances between the maxillary posterior roots apices and the MSF were recorded. The correlations of the distances with gender and age were analyzed. The distances between the maxillary posterior root apices and the MSF with different types of adjacent teeth loss was evaluated.

RESULTS

Type OS was the most common relationship of all posterior root apices (P<0.05). Type IS was highest in the palatal roots (PRs) of the maxillary first molars (MFMs) and the mesiobuccal roots (MBRs) of the maxillary second molars (MSMs) (24.8% and 21.6%) (P<0.05). The frequency of Type IS decreased with age except the premolar roots and PRs of the MSMs (P<0.05). The MBRs of the MSMs had the lowest distances to the MSF (0.8 ± 2.5 mm), followed by the distobuccal roots of the MSMs (1.3 ± 2.7 mm) and the PRs of the MFMs (1.4 ± 3.4 mm) (P<0.05). Age was an important influencing factor to the mean distances while gender had little effects. The distance between the maxillary second premolar root apices and the MSF decreased with the absence of adjacent teeth (P<0.05).

CONCLUSIONS

The maxillary molars showed greater proximity to the MSF than premolars. Age had significant impacts on the relationship between maxillary posterior roots and MSF. The absence of maxillary first molars will influence the proximity of maxillary second premolar root apices to MSF.

Proximity of the roots of posterior teeth to the maxillary sinus in different facial biotypes

INTRODUCTION

Orthodontists consider facial growth pattern and oral function when developing a treatment plan. Less attention is given to the relationship between the maxillary posterior teeth and the maxillary sinus. We aimed to evaluate the relationship between the roots of the maxillary posterior teeth and the floor of the maxillary sinus.

METHODS

Proximity of the roots to the maxillary sinus was scored for the left and right first and second premolars and molars (scores, 0-3). Mean scores per patient and per tooth type were calculated. The influences of age, sex, and facial biotype on mean scores per patient and tooth were analyzed.

RESULTS

The mean scores per patient and the second molar scores were significantly lower in the normodivergent subjects compared with the hypodivergent subjects, and in the hypodivergent vs the hyperdivergent groups, indicating that the hypodivergent biotype had significantly fewer second molar roots into the sinus than the normodivergent and hyperdivergent biotypes. Age had no effect on mean score per patient, but in the hyperdivergent group, the second molar score increased with age, meaning that second molar roots tend to be closer to the sinus floor.

CONCLUSIONS

In a young population (7-24 years), the positions of the apices of the maxillary second molar roots in relation to the maxillary sinus floor are associated with the facial biotype. In a hypodivergent biotype, the roots of the second molars are located farther from the sinus floor compared with the normodivergent and hyperdivergent facial patterns.

Evaluation of Single Tooth Loss to Maxillary Sinus and Surrounding Bone Anatomy With Cone-Beam Computed Tomography: A Multicenter Study

BACKGROUND

Posterior maxillary tooth loss may complicate the implant treatment due to the alterations in alveolar anatomy and maxillary sinus pneumatization. This study aimed to comprehensively examine the anatomical structure of this region from cone-beam computed tomography (CBCT) images.

MATERIALS AND METHODS

The posterior maxilla regions with single tooth loss were analyzed by dividing the variables into 3 subgroups from images of 597 patients chosen from 1160 CBCTs. Variables associated with sinus membrane (SM), sinus dimensions, ostium, septa, sinus neighborhood, alveolar bone height (ABH) and width (RW), posterior superior alveolar artery (PSAA), and adjacent roots were evaluated.

RESULTS

The majority of the patients demonstrated 0 to 5 mm membrane thickness. Irregular SM thickening was lower for female patients. While females showed higher number of narrow sinus, males had higher RW than females. Sinus augmentation classification showed negative correlation with ABH, root-tip sinus floor and edentulous site classification. Posterior septa height was correlated with number of septa and ABH. PSAA diameter and location were also correlated between each other.

CONCLUSION

The present results define formation of a sinus space with 11 mm coronal and 16 mm apical width after single tooth loss. A flat or semispherical thickening around 4 mm is usual in most cases with 51% possibility of anterior septum existence. A ridge anatomy, around 7.5 mm ABH and 7.2 to 9.3 RW from coronal to apical, complements this anatomy. Further studies are needed to clarify the reasons behind the SM and crestal anatomy variations between genders.

Three-dimensional CAD/CAM imaging of the maxillary sinus in ageing process

OBJECTIVES

During the physiological ageing process atrophy of the alveolar bone appears in vertical direction. This bone resorption causes pushing the limits of the maxillary sinus at the expense of a degraded bone. The sinus volume increases due to the facial development in children and adolescents or during the ageing process due to the loss of teeth and bone mass. The main aim of this study is to determine the sinus shape and sinus floor morphology related to age.

MATERIALS AND METHODS

Human adult male and female cadaveric heads (aged 37 to 83 years) with different dental status were used. The three-dimensional CAD/CAM software was used to scan the solid impressions of the maxillary sinus to visualize the real sinus shape and sinus floor. Subsequently, other findings are shown in tables and evaluated graphically.

RESULTS

The maxillary sinus morphology, its relationship to the nasal cavity, the sub sinus alveolar bone height, displacement of the lowest and highest points of sinus, and the sinus relationship to the roots of the upper teeth were studied and evaluated. Some septa, crests, and the prominent infraorbital canal were also found in the area of the sinus floor.

CONCLUSIONS

This paper provides a unique view on the maxillary sinus and its changes during the ageing process with preserved topographical relations in a representative sample of the Slovak population. The visualization of the maxillary sinus anatomy is necessary in the diagnosis and treatment plans for dental implants and during current surgical procedures.

Differences in distances between maxillary posterior root apices and the sinus floor according to skeletal pattern

INTRODUCTION

The aim of this study was to evaluate the distances from the maxillary posterior root apices to the inferior wall of the maxillary sinus using cone-beam computed tomography images and the relationships between roots and maxillary sinus according to age, sex, and skeletal pattern.

METHODS

Three-dimensional images of each root were checked, and the distances were measured along the true vertical axis from the apex of the root to the sinus floor in 118 patients (63 male, 55 female) aged 10 to 28 years. Compare-means statistic tests were done to assess the differences between groups classified according to age, sex, and skeletal pattern.

RESULTS

The frequency of root contact with the sinus floor increased from 70% at the second premolar to more than 80% at the buccal roots of the first and second molars. Male and older age (20-28 years) groups had significantly smaller distances or more protrusion of the root into the sinus than female and younger age (10-20 years) groups. The distances were shorter, or there was more protrusion of the root into the sinus in the hyperdivergent, down-canted palatal plane, and large gonial angle groups.

CONCLUSIONS

Male, older age, hyperdivergent skeletal pattern, and large gonial angle groups had significantly closer distances between maxillary root tips and the sinus floor or more protrusion of the roots into the sinus. The intrusion of the maxillary molars in those situations may be difficult and slow because of the pneumatized maxillary sinus.

Assessment of the relationship between the maxillary sinus floor and the upper posterior root tips: Clinical considerations

AIM

The purpose of the present study was to evaluate the relationship between the maxillary sinus floor and the upper posterior root tips in the Colombian population using cone-beam computed tomography.

METHODS

A total of 1656 roots were analyzed (1104 molars and 552 premolars), classified as types I (outside the maxillary sinus) and II (inside the maxillary sinus).

RESULTS

The results showed that the palatal root of the maxillary first molar was most frequently found inside the antrum.

CONCLUSIONS

Understanding the relationship between the maxillary sinus floor and the upper posterior root tips is important to the clinician when performing conventional or surgical endodontic treatment and conventional surgery procedures in order to minimize or avoid the risk of damaging the maxillary sinus.

Correlation between Endodontic Infection and Periodontal Disease and Their Association with Chronic Sinusitis: A Clinical-tomographic Study

INTRODUCTION

The proximity of the roots of maxillary posterior teeth to the maxillary sinus floor can be associated with the development of chronic maxillary sinusitis (CMS). Therefore, this study evaluated the correlation between the presence of endodontic infection and periodontal disease in maxillary posterior teeth and the presence of CMS.

METHODS

A total of 83 patients (159 maxillary sinuses) were selected and underwent clinical dental examination to assess tooth mobility and pulp condition. In addition, cone-beam computed tomography was performed to evaluate the presence of periapical lesion and periodontal bone loss, and measure the distance from the root apex to the cortical of the maxillary sinus. The maxillary sinuses were divided into 2 groups: CMS and no maxillary sinusitis. Data were analyzed using χ² test and binary logistic regression analysis (P < .05).

RESULTS

Periodontal disease was positively associated with CMS, leading to a 3.45-fold higher association between these disorders (P < .05). CMS was significantly more common in patients with periodontal disease or endodontic infection in close proximity with the maxillary sinus. Periodontal disease or endodontic infection that was more distant from the maxillary sinus was more common in patients with no maxillary sinusitis (P < .05). To the extent that the tooth is more distant from the maxillary sinus floor, the chance of presenting CMS is reduced up to 2.5-fold (P < .05).

CONCLUSION

Periodontal disease and proximity to the maxillary sinus are more common in cases of CMS, requiring a dental assessment and cone-beam computed tomography evaluation in patients with CMS with ineffective treatment.

Transcrestal sinus floor augmentation with immediate implant placement applied in three types of fresh extraction sockets: A clinical prospective study with 1-year follow-up

BACKGROUND

Immediate implant insertion and transcrestal sinus augmentation both can provide a lot of advantages for patients and clinicians.

OBJECTIVE

This prospective study aims to verify the use of a modified technique for immediate implant insertion simultaneously with sinus augmentation in different types of sockets.

MATERIALS AND METHODS

Thirty-seven patients were recruited for the clinical study and were divided into 3 groups according to the relationship of their maxillary molar roots and sinus floor: group 1 with none of the teeth roots contacts sinus floor; group 2 as at least 1 teeth root contacting sinus floor, but no root is observed penetrating into sinus cavity; group 3 with at least 1 teeth root penetrating into sinus cavity. Implants were inserted after transcrestal sinus floor augmentation and immediately after tooth extraction. The change of mucosa thickness, diagnosis of rhinosinusitis, marginal bone loss (MBL), pocket depth (PD), and sulcus bleeding index were examined through radiographic measurement or clinical monitoring.

RESULT

During the study period, no implants failed. The relationship of the root of maxillary molars and sinus floor may have an effect on the bone height of the interradicular crest. Sinus mucosa was observed thicker after surgery. After healing period, sinus mucosa returned as thin as presurgery. At the time of 1-year follow-up, MBL was measured on X-ray (group 1: mesial: 0.63 ± 0.20 mm, distal: 0.70 ± 0.14 mm; group 2: mesial: 0.67 ± 0.21, distal: 0.65 ± 0.22 mm; group 3: mesial: 0.70 ± 0.15 mm, distal: 0.73 ± 0.19 mm). No statistical difference was found in MBL and PD as well as bleeding index among 3 groups.

CONCLUSION

In consideration of the advantages of sinus floor augmentation and immediate implant placement, our clinical result confirms that it is promising to combine the 2 techniques for replacing maxillary molars especially when using residual roots as implant orientation and taking full advantage of the interradicular crest bone.

What is the frequency of anatomical variations and pathological findings in maxillary sinuses among patients subjected to maxillofacial cone beam computed tomography? A systematic review

Background

When considering dental implant rehabilitation in atrophic posterior sectors, the maxillary sinuses must be evaluated in detail. Knowledge of the anatomical variations and of the potential lesions found in these structures conditions the outcome of sinus lift procedures and therefore of the dental implants. A systematic review is made to determine the frequency of anatomical variations and pathological findings in maxillary sinuses among patients subjected to cone beam computed tomography (CBCT).

Material and Methods

A PubMed (MEDLINE) literature search was made of articles published up until 20 December 2015. The systematic review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA). The quality of the studies included in the review was assessed using the Methodological Index for Nonrandomized Studies (MINORS).

Results

The combinations of search terms resulted in a list of 3482 titles. Twenty-three studies finally met the inclusion criteria and were entered in the systematic review, comprising a total of 11,971 patients. The most common anatomical variations were pneumatization and sinus septa. The prevalence of maxillary sinus disease ranged from 7.5% to 66%. The most common pathological findings of the maxillary sinus were mucosal thickening, sinusitis and sinus opacification.

Conclusions

Although the main indication of CBCT of the maxillary sinus in dentistry is sinus floor elevation/treatment planning and evaluation prior to dental implant placement, this imaging modality is increasingly also used for endodontic and periodontal purposes. There is no consensus regarding the cutoff point beyond which mucosal thickening of the maxillary sinus should be regarded as pathological, and the definition of maxillary sinusitis moreover varies greatly in the scientific literature. In this regard, international consensus is required in relation to these concepts, with a clear distinction between healthy and diseased maxillary sinuses.

Key words:Maxillary sinus, cone beam computed tomography, dental implant, maxillary sinus floor augmentation, sinus membrane, sinus floor elevation.

Anatomic basis of Le Fort 1 impaction osteotomy: a radiological study

PURPOSE

In Le Fort 1 osteotomy when a maxillary impaction is necessary, surgeons have to face different anatomical problems. (1) To determine the best bone resection route, they have to consider the situation of dental roots, infraorbital foramen and maxillary artery. (2) In case of Le Fort 1 osteotomy combined with a mandibular sagittal split osteotomy, the palate has to be replaced in horizontal position although there is no anatomical landmark. (3) In case of Gummy smiles, it can be due to either long face or short upper lip. The main objective was to identify safe bony landmarks to perform a Le Fort I osteotomy and to find a reliable way for repositioning the palate horizontally; the secondary objective was to determine the upper lip normal length.

METHODS

The study was based on 178 facial CT examinations. The following parameters have been used: the vertical length of the upper lip, the vertical heights of the anterior nasal spine, the canine and molar roots, the inferior limit of the pterygomaxillary fossa and the vertical height of the infraorbital foramen on both sides.

RESULTS

The vertical length from the subnasal point to the upper vermilion was 15.06 ± 3.09 mm, and to the junction of the upper and lower lips was 23.94 ± 3.79 mm. The vertical length from the anterior nasal spine to the incisor alveolar border was 19.70 ± 3.17 mm. The height of the canine root was 17.11 ± 2.60 mm. The height of the highest lateral root of first or second maxillary molars was 11.71 ± 1.83 mm. The vertical length from the inferior limit of the pterygomaxillary fossa (pti point) to the alveolar border of the pterygomaxillary suture was 19.86 ± 3.45 mm. The height from the center of the infraorbital foramen to the alveolar border of the maxilla on a vertical line was not statistically different on right and left sides.

CONCLUSIONS

According to our results, in impaction Le Fort 1 osteotomy, the bone resection must pass 20 mm above the alveolar border in canine area, and 15 mm above the alveolar border in molar area. The resection has to end less than 20 mm above the inferior border of the pterygomaxillary suture. The vertical height of the infraorbital foramen is a consistent landmark for repositioning of the palate in a horizontal plane.

Comparison of panoramic radiography and CBCT to identify maxillary posterior roots invading the maxillary sinus

OBJECTIVES

Given the limitations of panoramic radiography for assessing topographic relationship of maxillary teeth with sinus floor, the purpose of this study was to assess signs on panoramic radiography that could predict root protrusion into the sinus.

METHODS

A total of 46 individuals (330 maxillary posterior teeth) who underwent panoramic radiography and CBCT were enrolled. The relationship between the posterior teeth and the maxillary sinus and panoramic radiography signs (projection of the root apices, interruption of the maxillary sinus floor, lamina dura, darkening in the root apices, and superiorly curving sinus floor enveloping the associated tooth root) associated with protrusion of root apices into the sinus were evaluated.

RESULTS

There were differences between the imaging modalities about the positioning of the root apices regarding the sinus (p < 0.05). Only the projecting of the root apices and the interruption of the sinus floor on panoramic radiography were predictors for the root protrusion (p < 0.05). No significant association was observed for the other panoramic radiography signs (p > 0.05).

CONCLUSIONS

The root projection into the sinus and the interruption of the sinus floor are indicative signs of root protrusion into the sinus on CBCT.

An Analysis of the Proximity of Maxillary Posterior Teeth to the Maxillary Sinus Using Cone-beam Computed Tomography

INTRODUCTION

It is known that the level of the maxillary sinus floor varies with age. Because few studies have investigated whether the position of the posterior roots relative to the maxillary sinus varied with the variation of the sinus floor or not, the present study assessed the position according to age.

METHODS

Cone-beam computed tomographic images of 848 patients were reconstructed to evaluate the position of the posterior roots relative to the sinus floor, which were divided into 3 types, and quantify the distances between posterior root apexes and the adjacent border of the sinus floor. Measurements were taken for each root, and data were correlated with age, which was divided into 4 groups (≤20 years, 21-40 years, 41-60 years, and >60 years).

RESULTS

A total of 3063 premolars and 3095 molars were evaluated. The mean distances from the root tips to the border of the maxillary sinus floor increased with increasing age. From the first and second premolar roots, the mean distances ranged from 3.6 ± 4.1 mm to 8.9 ± 4.6 mm and from 0.7 ± 3.3 mm to 5.3 ± 3.9 mm, respectively. From the mesiobuccal, distobuccal, and palatinal roots of the first molars, the mean distances were -0.4 ± 2.8 mm to 4.6 ± 4.0 mm, -0.3 ± 2.4 mm to 4.4 ± 3.8 mm, and -0.4 ± 3.5 mm to 3.9 ± 4.1 mm, respectively. From the mesiobuccal, distobuccal, and palatinal roots of the second molars, the mean distances were -0.5 ± 2.2 mm to 3.4 ± 3.5 mm, 0.3 ± 2.2 mm to 3.9 ± 3.7 mm, and 1.1 ± 3.2 mm to 4.6 ± 4.5 mm, respectively. The frequency of type IS decreased with increasing age. It was very low in first premolars (0%-8.13%) and higher in second premolars (0%-25.68%), first molars (0%-44.75%), and second molars (0%-32.89%). Age significantly influenced the mean distances to the sinus floor and the frequencies of type IS (inside).

CONCLUSIONS

Cone-beam computed tomographic imaging is an effective method to study the position of the posterior roots to the maxillary sinus floor. Variation in proximity measurements was found by age, with those under the age of 40 showing a greater likelihood of the position of maxillary roots above/inside the sinus floor.

Anatomical considerations for implant placements in first maxillary molar extracted sites in East Asian patients

PURPOSE

With the advent of cone-beam computed tomography (CBCT) for maxillofacial imaging, there has been a paradigm shift from two dimensional panoramic radiography to three dimensional imaging. This study investigated the microanatomy of the maxillary permanent first molar socket and its relationship to the floor of the maxillary sinus, especially for immediate or early implant placement.

MATERIALS AND RESULTS

Sixty CBCT scans of 30 Malay and 30 Chinese subjects were selected from over 300 archived images. Ninety-five percent of the subjects had sinus floor extending anterior to the first molar, while 72% had the floor dipping between the roots. Seventy-five percent of the patients had inter-radicular bone and almost 50% had intrusion of root apices into the floor of the maxillary sinus. The dimensions of the socket were as follows: the mean width was 11.42 ± 0.86 mm; the mean length was 7.70 ± 0.56 mm; the mean height on the coronal plane was 6.48 ± 3.77 mm while on the sagittal plane it was 6.85 ± 3.67 mm.

CONCLUSIONS

Any implant length greater than the mean height of the socket (approximately 7 mm) has a fair chance of perforation into the maxillary sinus if placed without any additional adjunct procedures. In addition, 50% of the apices opened into the maxillary sinus, thereby risking the creation of perforations or root displacements into the maxillary sinus during exodontia-mandating CBCT scanning prior to any surgical implant procedures.