Maxillary Molar Region Research Articles

Posterior superior alveolar nerve blocks: a randomised controlled, double blind trial.

Local anesthesia has been a boon for dentistry to allay the most common fear of pain among dental patients. Several techniques to achieve anesthesia for posterior maxillae have been advocated albeit with minor differences. We compared two techniques of posterior superior alveolar nerve block (PSANB), the one claimed to be "most accurate" to the one "most commonly used." This study was conducted to assess and compare the efficacy as well as complications of "the straight needle technique" to that of "the bent needle technique" for PSANB. We conducted a prospective, randomised, double blind study on 120 patients divided into two groups, using a 26-gauge, 38mm long needle with 2ml of 2% lignocaine hydrochloride with 1:200,000 adrenaline solution. Objective symptoms were evaluated by a single investigator. Cold test using ice was used to evaluate the status of pulpal anesthesia. Data thus obtained was subjected to statistical analysis. Out of the 120 blocks, 19 blocks failed. Statistical analysis found straight needle technique to be more successful than the bent needle technique (p=0.002). Both the techniques were equally effective for the first molar region on both right and left side (p=0.66 on right side and p=0.20 on left side). However, in the second and third molar region technique A was more effective than B (p=0.01) on right side only. On Left side, both techniques were equally effective (p=0.08). Sensitivity of the cold test was 82% which is quite high but the specificity was 68% which seems to be falling in the above average range only. Positive predictive value of 75 and negative predictive value of 76 was observed. We did not encounter any complications in this study. To the best of our knowledge, this is the first randomised controlled clinical study on PSANB techniques. This study suggests that the PSANB using the straight needle technique as advocated by Malamed [1] can be routinely and safely used to achieve anesthesia in the maxillary molar region and to great efficacy, with normal precautions.

The Ultrastructural Relationship Between Osteocytes and Dental Implants Following Osseointegration.

Osteocytes, the most abundant cells in bone, have multiple functions, including acting as mechanosensors and regulating mineralization. It is clear that osteocytes influence bone remodeling by controlling the differentiation and activity of osteoblasts and osteoclasts. Determining the relationship between titanium implants and osteocytes may therefore benefit our understanding of the process of osseointegration. The aim of this study was to visualize the ultrastructural relationship between osteocytes and the titanium implant surface following osseointegration in vivo. Titanium implants were placed in the maxillary molar regions of eight female Sprague Dawley rats, 3 months old. The animals were sacrificed 8 weeks after implantation, and undecalcified tissue sections were prepared. Resin-cast samples were subsequently acid-etched with 37% phosphoric acid prior to examination using scanning electron microscopy. Compared with mature bone, where the osteocytes were arranged in an ordered fashion, the osteocytes appeared less organized in the newly formed bone around the titanium implant. Further, a layer of mineralization with few organic components was observed on the implant surface. This study shows for the first time that osteocytes and their dendrites are directly connected with the implant surface. This study shows the direct anchorage of osteocytes via dendritic processes to a titanium implant surface in vivo. This suggests an important regulatory role for osteocytes and their lacunar-canalicular network in maintaining long-term osseointegration.

A modified, self-locking, sliding knot for minimally accessible intraoral regions

ObjectiveA secured surgical suture is essential for the reapproximation of divided tissues. These safest sutures are achieved by a sound knot-tying technique that exploits the properties of the suture material. However, there are certain intraoral sites which have minimal access such as the maxillary third molar region, where placing a knot is often difficult and time consuming. Hence, the objective of this paper is to propose a simple, self-locking, sliding knot with highly predictable knot placement and less chance of knot slippage and breaking. MethodThis paper describes a modified, self-locking, sliding knot, which we routinely use in minimally accessible intraoral regions. The modified, sliding knot-tying technique mentioned in this note involves the placement of two knots. The second knot purely serves the purpose of securing the initial knot. ConclusionsThis sliding knot technique is easy to master and it also allows precise and predictable placement of the knot. It is a less time-consuming suturing technique. This technique has a very less chance of knot slippage and knot breakage. We have employed this technique during suturing the maxillary third molar region and found it to be highly effective.

Short-term skeletal and dental changes following bone-borne versus tooth-borne surgically assisted rapid maxillary expansion: A randomized clinical trial study

AimTo evaluate and compare the short-term (post-retention) skeletal and dental changes following bone-borne and tooth-borne surgically assisted rapid maxillary expansion (SARME) using cone beam computed tomography (CBCT). Subjects and methodsIn this randomized clinical study, 30 patients with transverse maxillary deficiency underwent either tooth-borne (n = 15) or bone-borne (n = 15) SARME. Before treatment and immediately after the consolidation period, CBCT was obtained and the nasal floor width, interdental root distance, palatal bone width and interdental cusp distance were measured at first premolar and first molar regions of maxilla. ResultsTwenty eight patients completed the study protocol. In both tooth-borne (n = 13) and bone-borne (n = 15) groups the highest degree of expansion occurred in the dental arch, followed by palatal bone, and nasal floor (V-shaped widening in coronal dimension). The amount and pattern of expansion was comparable between anterior and posterior maxillary regions in each group (parallel posteroanterior expansion) and between the two groups. ConclusionDental and skeletal effects of tooth-borne and bone-borne devices were comparable. The overall complication rate was negligible. Selection of an expansion device should be based on each individual patient's requirements. Future long-term clinical trial studies to evaluate the stability and relapse of these two techniques are recommended.

Double teeth: evaluation of 10-years of clinical material

Abstract The aim of the study was to evaluate 10-years of clinical material referring to the rare dental abnormality of double teeth. The study material consisted of case records, operation-books and radiographic or photographic documentation on patients treated in the Department of Oral Surgery, Silesian Medical University, Katowice, from the 1st of June 2000 to the 31st of May 2010. The following features were considered important: age and sex, the reason why the patient reported for treatment, general state of health, the time of recognition and type of double teeth, location of double teeth, complaints and disturbances connected with double teeth, types of radiographs, the radiographic and macroscopic appearance of double teeth and treatment method. Diagnoses were as follows: eight conrescent teeth, two fused teeth, two geminated teeth and one invaginated tooth. The anomaly of a deciduous tooth was referred to in one case only. Double teeth were most often seen in the region of maxillary incisors and molars but rarely in the mandible. The region of incisors was affected chiefly in children and the region of molars in adults. Double incisors are usually recognized prior to treatment whereas double molars as late as during their extraction. In many cases, neither intraoral radiographs nor pantomographs help to confirm double teeth or provide sufficient information to plan the treatment. In such a situation, CT or CBCT should be used in addition to imaging diagnostics. Double teeth among incisors are usually accompanied by occlusal disorders. Therefore the therapeutic management is conducted by a team, including orthodontists.

Survival rate of Astra Tech implants with maxillary sinus lift

ObjectivesThe aim of this study was to retrospectively evaluate the clinical survival rate of Astra Tech implants in the maxillary molar region performed with sinus lift and bone graft.Materials and MethodsNinety-nine Astra Tech implants (Osseospeed) placed in the maxillary molar region using sinus lift from September 2009 to February 2012 were selected with a minimum follow-up period of 1 year. The height of alveolar bone, sinus approach technique, bone material and implant survival rate were evaluated.ResultsOf the 99 implants, the survival rate was 90.9%; 8 implants failed within 1 year after implant placement, and 1 implant failed 1 year after implant loading. All failed implants were placed with sinus lift simultaneously. The average height of alveolar bone before implant placement was 6.9 mm, while the height of alveolar bone of failed implants was 2.1 mm, on average.ConclusionAstra Tech implants placed in the maxillary molar region had generally good survival rates, but the relationship between reduced pre-implant alveolar bone height and implant failure requires further attention.

Occurrence Regions and Sites of Peri-implant Inflammation With Bone Resorption in Partially-edentulous Patients

Aim: The aim of this study was to clarify the occurrence regions and sites of peri-implant bone resorption and inflammation in partially-edentulous patients.Methods: Five hundred one partially-edentulous patients with 738 implants in function for more than 5 years were included in this study for the evaluation of the bone resorption by using dental radiograph and probing. Considering physiological bone remodeling, the mean mesio-distal bone resorption around the implant was measured on dental radiograph.Results: In 65 patients (13.0% of the total patients) with 76 implants (10.3% of the total implants), peri-implant bone resorption was identified. The mean functional loading time of these implants was 8.4 years. Occurrence regions were frequently found in the molar regions in maxilla (15.4%) and the molar region in mandible (10.0%) In these leisions detected radiologically, the bleeding on probing was seen in 95.2% of the buccal sites in mandibular molar regions, 70.0% of the palatal sites in maxillary molar regions and 56.7% of the buccal sites in maxillary molar regions with statistically significant differences.Conclusion: From the limitation of the information in this study, it was concluded that the sites that tend to be vulnerable to peri-implant inflammation were the buccal site in mandible, and the buccal and palatal sites in maxilla.

7本の埋伏過剰歯を認めた1例

The prevalence of supernumerary teeth is about 1 percent, but multiple supernumerary teeth are extremely rare. We report the case of a 15-year-old girl with seven impacted supernumerary teeth detected on panoramic radiographic examination. The panoramic X-ray film showed six supernumerary teeth impacted bilaterally in the canine-premolar region of the mandible and one supernumerary tooth impacted in the right maxillary molar region. On computed tomography, all of the impacted teeth were incompletely developed. We extracted all of the supernumerary teeth under general anesthesia. We pathologically examined the connective tissue surrounding the impacted teeth. Histopathologically, there were many small lumps of odontogenic epithelium in the connective tissue.

Prosthodontic treatment with dentures using a flat table in maxillary molar region of patients with unstable mandibular position

Prosthodontic treatment with dentures using a flat table in maxillary molar region of patients with unstable mandibular position

Stress Distribution during Rapid Canine Retraction with a Distraction Device: A Finite Element Study

Objective : To evaluate stress patterns in the maxillary canine and first molar region during rapid canine retraction by a distraction device and determine the amount of force generated by 0.5 mm activation of the distractor device in the 3D model of maxillary arch using finite element analysis. Materials and methods: For the study, 40 slices of 0.625 mm sections at 0.2 mm intervals of spiral computed tomographic (CT) scan of the maxilla with permanent dentition was taken using GE 64 slicer spiral CT in helical mode using version 4.2 Application Development Workbench (ADW) software and was simulated with 0.5 mm activation of the distractor device. Results: The stress was greatest in the molar region which generated a force of 214 g within the range of orthodontic forces. Conclusion: The periodontium in the maxillary first molar region showed the maximum stress and the canine showed unequal stress distribution with more stress at the crest of the alveolar bone and lesser stress at the apical region which lessens root resorption.

Assessment of Short Dental Implants Restored With Single-Unit Nonsplinted Restorations

To investigate the survival rate of short (≤9 mm) implants restored with single-unit, nonsplinted crowns after an average follow-up of 37 months (21-94 months). Two hundred and twenty-one implants placed in 168 patients (74 men, 94 women, aged 34-87 years, mean = 61 years). Implant lengths were 6 (n = 16), 8 (n = 166), 8.5 (n = 2), or 9 mm (n = 34). The implant diameters ranged from 3.7 to 5.6 mm. Implants were placed in the maxillary (n = 44) and mandibular arches (n = 176). Survival rate was 94.1% (maxilla [88.6%] and mandible [96.0%]) and 12 early failures (first 4 months) and 1 late failure (4.5 years in the maxillary molar region) observed. Of the 12 early failures, 4 were in the maxilla (2 premolars and 2 molars) and 8 in the mandible (2 premolars and 6 molars). The early failures were 11 implants of 8 mm long and a 9-mm implant. Smoking cigarettes, diabetes mellitus, and bone augmentation procedures were not associated with implant failure significantly (P > 0.05). Survival rate of short implants restored with single-unit, nonsplinted restorations over an average period of 37 months was favorable and comparable with longer implants.

Soft and Hard Tissues Healing at Immediate Transmucosal Implants Placed Into Molar Extraction Sites With Collagen Membrane Uncovered

To assess soft and hard tissues healing at immediate transmucosal implants placed into maxillary molar region with collagen membranes uncovered. Twenty subjects received 20 immediate transmucosal implants placed in maxillary molar extraction sockets. Periimplant marginal defects were treated according to the principles of guided bone regeneration by means of deproteinized bovine bone mineral particles in conjunction with collagen membrane. Flaps were repositioned and sutured, allowing nonsubmerged, transmucosal soft tissues healing. The collagen membranes adapted around implant neck were uncovered. No implants were lost during the 1-year observation period yielding a survival rate of 100%. No postsurgical wound healing complications were observed. No degranulation of grafting material was reported. The results of this 12-month prospective study showed that the exposure of collagen membrane at time of the flap suturing does not represent a limitation for the soft and hard tissues healing at immediate transmucosal implants placed into maxillary molar extraction sites.

Sequential test selection by quantifying of the reduction in diagnostic uncertainty for the diagnosis of proximal caries.

In order to determine the presence or absence of a certain disease, multiple diagnostic tests may be necessary. Performance of these tests can be sequentially evaluated. The aim of the study is to determine the contribution of the test in each step, in reducing diagnostic uncertainty when multiple tests are sequentially used for the diagnosis. Diagnostic accuracy study. Radiographs of seventy-three patients of the Department of Dento-Maxillofacial Radiology of Hacettepe University Faculty of Dentistry were assessed. Panoramic (PAN), full mouth intraoral (FM), and bitewing (BW) radiographs were used for the diagnosis of proximal caries in the maxillary and mandibular molar regions. Diagnostic performance of radiography was sequentially evaluated by using the reduction in diagnostic uncertainty. FM provided maximum diagnostic information for ruling in potential in the maxillary and mandibular molar regions in the first step. FM provided more diagnostic information than BW radiographs for ruling in the mandibular region in the second step. In the mandibular region, BW radiographs provided more diagnostic information than FM for ruling out in the first step. The presented method in this study provides the clinicians with a solution for the decision of the sequential selection of diagnostic tests for the correct diagnosis of the presence or absence of a certain disease.

Endodontic and Surgical Treatment of Root Damage Caused by Orthodontic Miniscrew Placement

IntroductionMiniscrews are being increasingly used for anchorage control in orthodontics. Despite the concern over root damage caused by miniscrews, there are few reports of precise clinical evaluations and appropriate management of that damage. In the case presented herein, the root damage caused by the placement of miniscrews was repaired by root canal treatment and surgical intervention. MethodsA 44-year-old man received orthodontic treatment for intrusion of the left maxillary first molar with a miniscrew anchorage system. During that treatment, the miniscrews had fallen out and had to be reinserted more than 6 times in the same area. Two years later, the patient complained of a spontaneous pain in the maxillary left molar region. Although the patient received root canal treatment, intraoral sinus tracts could still be detected, and the patient's discomfort persisted. Periradicular surgery revealed that the persistent infection was related to root surface damage caused by orthodontic miniscrew placement. Healing was achieved by a combination of root canal treatment and surgical intervention. ResultsScanning electron microscopy of the damaged distobuccal root apex revealed a mature biofilm consisting of a network of matrix that contained mostly rod-like and spherical bacteria. At a 12-month recall checkup, the patient was free of pain. A repeat periapical radiograph revealed reduction of the pretreatment radiolucent lesion. ConclusionsMore careful planning of miniscrew placement is necessary to lessen the danger of root damage. Furthermore, a precise evaluation of both root and pulpal damage and careful consideration of the choice of optimal treatment modality are needed.

Real‐time thermographic analysis of low‐density bone during implant placement: a randomized parallel‐group clinical study comparing lateral condensation with bone drilling surgical technique

To compare the effect of two surgical techniques, lateral condensation and bone drilling, on changes in temperature of the adjacent low-density bone during implant placement into posterior maxilla and to investigate the influence of the host factors - age, gender, region of implantation, bone density, and thickness of the cortical bone at the recipient sites. Local bone temperature was measured thermographically during implant placement into posterior maxilla following lateral bone condensing (test group) or bone drilling (controls). The main study outcomes were baseline bone temperature prior to implantation and maximum bone temperature recorded during implantation. Early implant success was evaluated after 6 months of healing. A total of 40 implants were randomly allocated to test and control groups and placed into maxillary premolar and/or molar region of 18 participants of both genders and average age of 51.74 years. All recorded bone temperatures were below the threshold for thermal necrosis. Although both groups showed significant increase in bone temperature during implant placement procedure (P ≤ 0.0005), it was significantly higher for bone condensing compared with drilling (P ≤ 0.0005; 3.79 ± 1.54°C; 1.91 ± 0.70°C respectively). No host factor was singled out as a significant predictor of bone temperature changes, although trend of higher increase was observed in young patients, regardless of gender, during implant placement procedure into maxillary first premolar region with bone density type 3 and cortical layer thicker than 1 mm. Early implant success rate after 6 months follow-up was 100%. Although both surgical techniques, bone condensing and bone drilling, can be considered safe regarding their thermal effect on the bone of posterior maxilla, bone drilling is associated with fewer local bone heating during implantation. Host factors do not affect the bone thermal changes significantly.

Maxillary Posterior Bone Height in Relation to Maxillary Sinus Floor in Indian Dentulous Population

To establish a ratio of variable bone height (Infrazygomatic alveolar crest height) to constant bone height (Infraorbital zygomatic height) and, to estimate the relative sinus floor position from alveolar crest of maxillary first molar region of dentulous Indian males and females, using Digital panoramic radiographs. Panoramic radiographs of 74 patients were included in the study (37 male, 37 female) to measure maxillary posterior vertical bone height and their ratio in dentulous patients. Measurements were made from reference lines drawn from anatomic landmarks on soft digital versions of standardized panoramic radiographs using Kodak dental imaging software. Later the data were analyzed using normal test (Z-score). When the posterior maxillary bone height and their ratio were evaluated in Indian population, the vertical bone height (x, y, z) of males was more than the females. Ratio of Infrazygomatic-alveolar crest distance (y)/Infraorbital-zygomatic distance (x)-was 0.74 for Indian males and females. The relative sinus floor for Indian males was found to be 8.1mm and that of Indian females to be 7.8mm. The results are of significant value as "baseline" data, in serial studies where alveolar bone height for a single patient is compared at different times before and after tooth loss. The relative sinus floor position from alveolar crest can help in implant length selection. This study can be used as a diagnostic and predictive tool in implant treatment planning but further long-term evaluation is still required to prove the efficacy of this study.

Factors affecting the accuracy of buccal alveolar bone height measurements from cone-beam computed tomography images

The reasons for inaccuracies in alveolar bone measurement from cone-beam computed tomography (CBCT) images might be multifactorial. In this study, we investigated the impact of software, the presence or absence of soft tissues, the voxel size of the scan, and the regions in the jaws on buccal alveolar bone height measurements in pigs at an age equivalent to human adolescents. Marker holes, apical to the maxillary and mandibular molar roots, and mesiodistal molar occlusal reference grooves were created in 6 fresh pig heads (12 for each jaw), followed by CBCT scans at 0.4-mm and 0.2-mm voxel sizes under soft-tissue presence and soft-tissue absence conditions. Subsequently, buccolingual sections bisecting the marker holes were cut, from which the physical alveolar bone height and thickness were measured. One blinded rater, using Dolphin (version 11.5 Premium; Dolphin Imaging, Chatsworth, Calif) and OsiriX (version 3.9; www.osirix-viewer.com) software, independently collected alveolar bone height measurements from the CBCT images. Differences between the CBCT and the physical measurements were calculated. The mean differences and the limit of agreement (LOA, ±1.96 SD) for every jaw, voxel-size, soft-tissue, and software condition were depicted. Each measurement was then assessed for clinical inaccuracy by using 2 levels of criteria (absolute differences between CBCT and physical measurements ≥1 mm, or absolute differences between CBCT and physical measurements ≥0.5 mm), and the interactions between soft-tissue and voxel-size factors for every jaw and software condition were assessed by chi-square tests. Overall, the mean differences between the CBCT and the physical measurements for every jaw, voxel-size, soft-tissue, and software condition were near 0. With all other conditions kept equal, the accuracy of the maxillary CBCT measurements was inferior (larger limit of agreement ranges and higher frequencies of clinical inaccuracy) to the mandibular measurements. The physical thickness of the maxillary alveolar crestal bone was less than 1 mm and significantly thinner than the mandibular counterparts. For every jaw and software condition, the accuracy of measurements from the 0.2-mm soft-tissue presence CBCT images was consistently superior (smaller limit of agreement ranges and lower frequencies of clinical inaccuracy) to those from the 0.4-mm soft-tissue presence, the 0.4-mm soft-tissue absence, and the 0.2-mm soft-tissue absence images; all showed similar accuracies. Qualitatively, the soft-tissue absence images demonstrated much brighter enamel and alveolar bone surface contours than did the soft-tissue presence images. At an adolescent age, the buccal alveolar bone height measured from the maxillary molar region based on 0.4-mm voxel-size CBCT images can have relatively large and frequently inaccurate measurements, possibly due to its thinness. By using 0.2-mm voxel-size scans, measurement accuracy might be improved, but only when the overlying facial and gingival tissues are kept intact.

Age‐related changes in maxillary and mandibular cortical bone thickness in relation to temporary anchorage device placement

The aim of this study was to investigate the correlation between alveolar bone cortical thickness (ABCT) and age in the maxillae and mandible in humans. This information could then be translated into clinical application with temporary anchorage devices (TADs) in orthdontics. Samples comprised 82 post-mortem CT datasets (41 males and 41 females) aged between 11 to 50 years, and were divided into five different age groups and gender. Alveolar ABCT was measured in the labial/buccal and palatal/lingual sides of the incisor, canine, premolar, molar and tuberosity/retromolar regions of the maxillae and mandible. Correlations between ABCT and age and gender were analysed with linear regression analysis. Strong correlation between ABCT and age was found for the maxilla on the labial side of the maxillary incisor region (p < 0.001). On the palatal aspect, significant correlations between ABCT and age were found in the maxillary incisor and maxillary premolar regions (p = 0.01 and p = 0.047 respectively). Significant correlation between ABCT and gender was found only at the buccal aspect of the maxillary molar region (p = 0.022). In the mandible, a statistically significant correlation between ABCT and age was found in the cortical bone of the labial side of the mandibular incisor region (p = 0.017). However, statistically significant negative correlation between ABCT and age was found in the mandibular canine region (p = 0.033). The only site to demonstrate a significant difference in change in ABCT with age between males and females was the lingual side of the retromolar region, in which female ABCT increased more than in males (slope = 0.015). There is minimal clinically significant correlation between ABCT and age at the alveolar bone level. Although investigations show statistically significant correlations, these may not be clinically significant as those regions are not ideal for anchorage reinforcement with TADs in orthodontic practice.

A Comparison of Manual and Electrical Mallet in Maxillary Bone Condensing for Immediately Loaded Implants: A Randomized Study

The aim of this clinical study was to compare electrical versus hand mallet in osteotome-assisted surgery for maxillary bone condensing in immediately loaded implant procedure. Edentulous patients in maxillary premolar and molar regions with type III or IV bone were enrolled in this prospective clinical study. The patients were randomly divided in two groups: in the test group (magnetic mallet group [MMG]), the implant site was prepared with osteotomes pushed by electrical mallet, while in the control group (hand mallet group [HMG]), the implant site was performed with osteotomes pressed by hand mallet. Implants were immediately loaded. Intraoral digital radiographic measurements were reported at 6, 12, and 24 months. Fifty patients were enrolled in the study. Twenty-five patients were included in MMG and 25 patients in the HMG. One hundred thirty-eight dental implants were placed. In 12 cases, six in MMG and six in HMG, sinus elevation was performed. After 24-month follow-up, a survival rate of 94.93% was reported (MMG and HMG reported a survival rate of 97.10 and 92.75%, respectively, not statistically significant [P > .05]). In control group, two patients claimed benign paroxysmal positional vertigo following the use of osteotomes with hand hammer. Marginal bone levels remained stable over time for both groups, and no statistically significant differences were found. After 12 months, the bone height increased in both groups and, at 24 months, was stable. Statistical analysis reported no significant differences between test and control groups. These results demonstrated a stable marginal bone levels over time and a significant increase in bone height between 6 and 12 months in osteotome technique. The use of electrical mallet provided some essential clinical advantages for the patients during surgical procedure in comparison with hand mallet.

A modified Thermoplastic Retainer

The aim of this article is to describe a method for fabricating a new esthetic maxillary retainer. To fabricate this retainer it is necessary to fit a segment of orthodontic wire in the maxillary molar and premolar region, followed by plasticization of the model. In order to allow occlusal finishing the occlusal and incisal surfaces of the plate are removed. The described retainer can be a useful alternative to the orthodontist for esthetic orthodontic retention.