Intraoral Group Research Articles

Effectiveness of Transcutaneous Electric Nerve Stimulation for Controlling Pain after the Archwire Placement

Introduction: The aim of the study was to evaluate the effectiveness of transcutaneous electric nerve stimulation (TENS) for controlling pain after the archwire placement and then comparison between the placebo, extra-oral, and intra-oral group depending upon the electrode placement. Materials and Methods: The study consists of a sample size of 90 patients who were further divided into three groups. Each group had 30 samples each, and the groups were divided into placebo group, extra-oral TENS group, and intra-oral TENS group. TENS application was done after the bonding and ligation of initial archwire. The patients were asked to record the level of pain on a VAS form at 4 hours, 8 hours, 12 hours, 24 hours, and 48 hours interval. Result: On comparison of VAS of all the three groups at 8 hours intervals significant result (P = 0.037) has occurred. Individual intra-group comparison has also shown some significant result. Conclusion: TENS being a non-pharmacological, non-invasive method for controlling pain is found to be effective. Both the extra-oral and intra-oral applications are effective.

Comparative evaluation of the effectiveness of intracanal and intraoral cryotherapy on postendodontic pain in patients with symptomatic apical periodontitis: A randomized clinical trial.

There is a rising need for controlling postendodontic pain (PEP) without using analgesics and other conventional methods. The aim of the study is to compare the effectiveness of various cryotherapy applications on controlling PEP in patients with symptomatic apical periodontitis. One hundred and eight patients were selected and preoperative pain and pain on percussion scores were recorded using Numeric Rating Scale (NRS) and Visual Analog Scale (VAS), respectively. After obtaining consent, the access cavity was prepared under local anesthesia. After cleaning and shaping, the patients were randomized into the following groups: Group A: Canals were given final irrigation with 20 mL room temperature saline solution for 5 min, Group B: Canals were given final irrigation with 20 mL cold (2°C-4°C) saline solution for 5 min, and Group C: After obturation and restoration procedures, small ice packs of size 2 cm × 2 cm × 2.5 cm (wrapped in sterile gauze) were placed intraorally on the vestibular surface of the treated tooth. At 6 h, postoperative pain was measured using NRS and at 24 h, pain and pain on percussion were measured using NRS and VAS, respectively. Data were analyzed using SPSS software. There was a significant reduction in postoperative pain in the intracanal and intraoral groups at 6 and 24 h when compared with the control group individually. There was no significant difference in postendodontic between intracanal and intraoral cryotherapy groups at 6 and 24 h. Both intracanal and intraoral cryotherapy applications are effective in reducing PEP in patients with symptomatic apical periodontitis.

Assessment of Occlusal Vertical Dimension Change in Mechanical and Virtual Articulation: A Pilot Study.

The aim of this clinical study was to investigate the change in occlusal vertical dimension (OVD) with dental casts mounted on a mechanical articulator using an average axis facebow and on a virtual articulator mounted using the Bonwill triangle and the Balkwill angle and compare these groups with OVD change observed clinically in patients. Casts were obtained from each patient (n = 14) and mounted on a semi-adjustable articulator in the facebow preservation group (FPG) and on a virtual articulator using average anatomic values in the average mounting group (AMG). Customized mandibular anterior splints were virtually designed at an OVD increased by 3, 6, and 9 mm. Digital buccal scans were performed with the anterior devices in the participants' mouths in the intraoral group (IOG), AMG, and FPG at the different OVD increases accordingly. While no statistically significant differences (p > 0.05) were observed in the posterior interocclusal measurements with the incisal guide pin raised by 3 mm and 6 mm among all groups, a 9 mm increase resulted in a significant difference between AMG and IOG. The interocclusal posterior-to-anterior opening ratio observed clinically was 1:1.575. Increases in OVD up to 6 mm on dental casts mounted using average anatomic values performed similarly to the actual intraoral changes.

Intraoral versus transcervical approaches in mandibular reconstruction with free flaps: A retrospective study

This study aims to investigate the clinical and functional differences between intraoral and transcervical approaches for segmental mandible resection and reconstruction with free flaps. Patients diagnosed as benign and low-grade mandibular malignant tumors without neck dissections were retrospectively reviewed and divided into intraoral and transcervical groups. Patients of intraoral group underwent intraoral mandibulectomy and vascular anastomosis was performed through a 2-cm submandibular incision, while traditional submandibular approach was used in transcervical group. Clinical characteristics of two groups were assessed including body mass index (BMI), defect types and number of fibular segments, as well as perioperative variables such as operation time, blood loss, drainage volume. The score of appearance, swallowing and speech using the University of Washington Quality of Life Questionnaire (UW-QOL) was recorded and analyzed 6-month postoperatively.A total of 14 patients in intraoral group and 21 patients in transcervical group was collected, respectively. In intraoral group, intraoperative blood loss and postoperative drainage volume were significantly reduced in comparison with transcervical group (p = 0.0146, p = 0.0017; respectively). The score of appearance was 87.50 ± 12.97 in intraoral group, which was significantly higher than 64.29 ± 12.68 in transcervical group (p < 0.0001). Similar results were found in patients of subtype Class II mandibular defect between two groups. However, patients of intraoral group had a significant increase in operative time and a comparable amount of intraoperative blood loss (p = 0.0472, p = 0.1434; respectively).Within the limitations of the study it seems that an intraoral approach combined with a 2-cm submandibular incision should be preferred over a transcervical approach for segmental mandibulectomy and free flap reconstruction whenever appropriate.

Transoral versus Transcervical Drainage of Pharyngeal Abscesses in Children: Post-Operative Complications

The objective of this study was to compare complications and other perioperative outcomes between intraoral and transcervical drainage of both retropharyngeal and parapharyngeal abscesses. This was a retrospective study that analyzed data from the 2012 to 2016 National Surgical Quality Improvement Program (NSQIP)-Pediatric public use files. Baseline characteristics and perioperative outcomes including postoperative complications and length of hospital stay (LOS) were compared between intraoral and transcervical drainage groups. Multivariable logistic regression was performed to inspect predictors of having an extended LOS, defined as LOS greater than 3 days. A total of 1174 patients were included. Mean age was 5.1 ± 3.8 years in the intraoral group (N = 1063) and 4.2 ± 4.3 years in the transcervical group (N = 111, P < .001). There was no significant difference in the rate of post-operative complications between groups (5.7% intraoral vs 8.1% transcervical, P = .316). LOS was significantly longer in the transcervical group (>3 days in 36.2% of intraoral vs 49.5% of transcervical, P = .006). Patients in the transcervical group had 1.59 times the odds of extended LOS, after adjusting for age, pre-operative ventilator support, asthma, structural pulmonary disease, hematologic disorders, and all post-operative complications (P = .024). There does not appear to be a significant difference in the rate of post-operative complications after intraoral versus transcervical drainage for pharyngeal abscesses in children. However, transcervical drainage was associated with an extended hospital stay. Further prospective studies will be needed to determine the reasons for this.

Management of Atrophic Mandibular Fractures in Pakistan – Changing Trends with Preference to Extra-Oral Approach

Background: With the ever-increasing incidence of facial trauma in geriatric population, it is very important to improve the care given to these patients. This study has been focused on determining a better approach for management of atrophic mandibular fractures. &nbsp;Objective: To compare the frequency of complications of extra-oral versus intra-oral approach for the management of atrophic mandible fractures. Study Design: Randomized control trial. Settings: Outdoor patient of department of Oral and Maxillofacial Surgery, Mayo Hospital, Lahore Pakistan. Duration: One year, 20th January, 2018 till 20th January, 2019. Methodology: Seventy consecutive patients were included in this study from the OPD of Oral and Maxillofacial Surgery. All the patients were randomly assorted in the both groups, group A being the intra-oral approach and group B being the extra-oral approach. The outcome was determined on the basis of presence or absence of mal-union or non-union after the fractures were treated. Results: The mean age of cases in extra and intra oral group was 76.54±8.13 years and 73.66± 8.04 years. In extra-oral group, there were 21(60%) male and 14(40%) females and in intra-oral group, there were 25(71/4%) male and 10(28.6%) female cases. In extra –oral group 3(8.6%) cases had complication and in intra-oral group 2(5.7%) cases had complications, the frequency of complication in both groups, p-value &gt;0.05. Among complications in extra-oral group 2(5.7%) cases had non-union and 1(2.9%) had malunion and in intra-oral group 1(2.9%) cases had non-union and malunion each. The frequency of type of complication was statistically same in both group, p-value &gt;0.05. &nbsp;Conclusion: The incidence of complications is statistically same in both groups. Hence, we encourage the use of extra-oral approach for management of atrophic fractures of mandible.

Outcomes of extra oral versus intraoral approach for Mandibular angle fracture reduction

Abstract&#x0D; Objective: To compare the outcomes of intraoral versus extraoral approach in the treatment of mandibular angle fracture.&#x0D; Method: The randomised controlled trail was conducted at the Department of Maxillofacial Surgery, Mayo Hospital, Lahore Pakistan, from September 2016 to March 2017, and comprised patients of mandibular angle fracture who were divided into two equal extraoral group A and intraoral group B. . Baseline and post-operative data on 1st and 7th days as well as 3 months following the surgery was collected. Data was analysed using SPSS 20.&#x0D; Results: Of the 100 patients, there were 50(50%) in each of the two groups. Mean age of group A was 32.28±7.79 years compared to 33.72±8.13 years in group B. There were 39 (78%) males in group A and 36(72%) in group B. The mean pain score at baseline in the groups was not significantly different (p=0.795). On the 7th day and 3 months post-operation, mean pain score was significantly lower in group A (p=0.002). Nerve complication in group A was significantly high compared to group A (p=0.005).&#x0D; Conclusion: Extra oral approach for the management of mandibular angle fracture is better with regards to pain while intra-oral approach is less associated with nerve complications.&#x0D; Key Words: Angle of mandible, Fracture, Intraoral approach, Extraoral approach, Incision.

Mandibular angle fractures- intra oral and extra oral approaches – A comparative study

Aim: The aim of this study was to analyze outcomes of intra-oral and extra-oral approaches to mandibular angle fractures. Materials and Methods: a retrospective study was performed of patients who underwent open reduction and internal fixation of mandibular angle fractures. Inpatient and outpatient records were reviewed for pertinent data including age, gender, presence of other fractures, surgical approach, operative time, and post-operative complications. Results: The 40 patients with angle fracture, 60% were treated vis intra-oral approach and the rest 40% via extra-oral approach. The mean age of the patients were 30.87 years in the intra-oral group and 34.13 years in the extra-oral group. Main etiology of injury was RTA. The mean operating time for the intra-oral group was 95.63 minutes and 100.43 minutes for the extra-oral group. There was not much of difference in length of hospital stay for both the groups the mean being 2 days. Malocclusion was seen in 17.4% of extra-oral cases and 12.5% of intra-oral group. Re-surgery was performed in 12.5% of the extra-oral cases. Post-op infection was observed in 13% of intra-oral cases and 31.3% of extra-oral cases. Neurosensory disturbance occurred in 30% of extra-oral cases, and none in the intra-oral group, which is statistically significant. (p-0.017). Conclusion: Both methods of fixation for angle fractures are useful in the treatment. On the basis of our results we recommend using intra-oral approach while clinically favorable with single miniplate along superior border. Keywords: Mandbular angle fracture, Intraoral versus extra oral approach.

Accuracy of implant position when placed using static computer-assisted implant surgical guides manufactured with two different optical scanning techniques: a randomized clinical trial

Data from cone beam computed tomography (CBCT) and optical scans (intraoral or model scanner) are required for computer-assisted implant surgery (CAIS). This study compared the accuracy of implant position when placed with CAIS guides produced by intraoral and extraoral (model) scanning. Forty-seven patients received 60 single implants by means of CAIS. Each implant was randomly assigned to either the intraoral group (n=30) (Trios Scanner, 3Shape) or extraoral group (n=30), in which stereolithographic surgical guides were manufactured after conventional impression and extraoral scanning of the stone model (D900L Lab Scanner, 3Shape). CBCT and surface scan data were imported into coDiagnostiX software for virtual implant position planning and surgical guide design. Postoperative CBCT scans were obtained. Software was used to compare the deviation between the planned and final positions. Average deviation for the intraoral vs. model scan groups was 2.42°±1.47° vs. 3.23°±2.09° for implant angle, 0.87±0.49mm vs. 1.01±0.56mm for implant platform, and 1.10±0.53mm vs. 1.38±0.68mm for implant apex; there was no statistically significant difference between the groups (P>0.05). CAIS conducted with stereolithographic guides manufactured by means of intraoral or extraoral scans appears to result in equal accuracy of implant positioning.

A comparative study of intraoral versus retromandibular approach in the management of subcondylar fracture

BackgroundThe purpose of this study was to compare the outcomes and effectiveness between intraoral approach and retromandibular approach for treatment of subcondylar fracture of mandible.MethodsBetween March 2011 and October 2013, 24 patients with subcondylar fractures of the mandible were treated by a single surgeon with an intraoral approach using an angulated screwdriver (n = 14) or by another surgeon using a retromandibular approach (n = 10). The interincisal distance was measured 1 week (T0), 6 weeks (T1), 3 months (T2), and 6 months (T3) postoperatively. We also compare the average operation time and the cost of operation between the two groups.ResultsAt 6 months postoperatively, all 24 patients achieved satisfactory ranges of temporomandibular joint movement, with an interincisal distance > 40 mm without deviation and with stable centric occlusion. The intraoral group had the median interincisal distance of 14 mm at T0, 38 mm at T1, 42.5 mm at T2, and 43 mm at T3, while the retromandibular group had that of 15, 29, 35, and 42.5 mm respectively. There was no statistically significant difference between the intraoral and the retromandibular group at T0 and T4. However, significant differences were noted T1 and T2 (p < 0.01). The differences of average operation time between the intraoral (81 min) and retromandibular group (45 min) were statistically significant (p < 0.01). The cost of an operation was 369.96 ± 8.14 (United States dollar [USD]) in intraoral group and was 345.48 ± 0.0 (USD) in retromandibular group. The differences between the two groups were statistically significant (p < 0.01).ConclusionIn open reduction of a subcondylar fracture of the mandible, a intraoral approach using an angulated screwdriver is superior to the retromandibular approach in terms of interincisal distance, although the operation time is longer.

Comparison of Therapeutic Effects of Intra and Extra Oral Low Level Laser Radiation in Maxillary Chronic Sinusitis

Chronic sinusitis is one of the most common chronic diseases. In this research, intra- oral radiation of low-level laser has been compared with extra-oral low level laser radiation in treating maxillary chronic sinusitis for the first time. In this clinical trial, 40 patients were enrolled. Treatment plan was performed in 8 sessions, every other day, and using low-level diode laser with 810 nm. SNOT-22 questionnaire and rhinomanometry were used for evaluating patients. Mann whiteny, Fridman and wilcoxson tests were used for data analyses. P. value < 0.05 was considered statistically significant. All studied variables were improved using intra and extra oral low-level laser and this improvement was statistically significant (P. value<0.05). Comparing the two groups, Intra-oral laser therapy significantly (P. value<0.05) improved rhinomanometry variables compared to extra-oral laser therapy. The two groups showed no significant difference in improvement of clinical symptoms that contained in the SNOT-22 questionnaire except for sneeze which intra-oral laser therapy significantly decreased this variable (P. value<0.05). It should be noted that intra-oral radiation reduced all symptoms earlier than extra-oral radiation. After Six-months, in intra-oral group there was no significant difference between the results of completion and the results of 8th treatment session (P. value> 0.05). But in extra-oral group only post nasal discharge and thick nasal discharge were significantly increased compared with the results of the 8th session of radiation. Other symptoms showed no significant difference (P. value>0.05). Using intra and extra oral low-level laser therapy is a suitable way to treat patients with chronic maxillary sinusitis.

The Effects of Transcutaneous and Intraoral Low-Level Laser Therapy After Extraction of Lower Third Molars: A Randomized Single Blind, Placebo Controlled Dual-Center Study.

The surgical removal of impacted third molars is one of the most common procedures performed by oral and maxillofacial surgeons. The purpose of this study is to determine whether either transcutaneous or intraoral low-level laser therapy (LLLT) reduces postoperative pain and assists in the healing of mandibular third molar extraction. This randomized, placebo controlled, single-blind, split-mouth design study was conducted on 60 patients with full bony impacted similar position mandibular third molars bilaterally. The patients were divided into two groups of 30 each: transcutaneous LLLT and intraoral LLLT and the other side of each group treated with nonactive laser (60 teeth). The laser treatment consisted of administering laser energy immediately before and after the extraction procedure with gallium aluminum arsenide (GaAlAs) 830 nm diode lasers. Postoperative pain and healing of the sockets were compared in transcutaneous and intraoral group with placebo for 1 week following the extraction. Descriptive and bivariate statistics was computed, and the p-value was set at 0.05. Intraoral LLLT application resulted in a statistically significant reduction of postoperative pain in comparison with transcutaneous laser group and placebo. The unhealed socket numbers were compared in two groups at seventh day and no differences were observed. The results of this study suggest that single-session intraoral LLLT is more effective than extraoral application for reducing postoperative pain. It was postulated that the differences between skin and mucosa could have effect on the results. Although intraoral use would allow closer application to the surgical site, the size of some laser devices precludes their use intraorally.

Influence of abutment tooth geometry on the accuracy of conventional and digital methods of obtaining dental impressions

Statement of problemDirect (intraoral) and indirect (desktop) digital scanning can record abutment tooth preparations despite their geometry. However, little peer-reviewed information is available regarding the influence of abutment tooth geometry on the accuracy of digital methods of obtaining dental impressions. PurposeThe purpose of this in vitro study was to evaluate the influence of abutment tooth geometry on the accuracy of conventional and digital methods of obtaining dental impressions in terms of trueness and precision. Material and methodsCrown preparations with known total occlusal convergence (TOC) angles (−8, −6, −4, 0, 4, 8, 12, 16, and 22 degrees) were digitally created from a maxillary left central incisor and printed in acrylic resin. Each of these 9 reference models was scanned with a highly accurate reference scanner and saved in standard tessellation language (STL) format. Then, 5 conventional polyvinyl siloxane (PVS) impressions were made from each reference model, which was poured with Type IV dental stone scanned using both the reference scanner (group PVS) and the desktop scanner and exported as STL files. Additionally, direct digital impressions (intraoral group) of the reference models were made, and the STL files were exported. The STL files from the impressions obtained were compared with the original geometry of the reference model (trueness) and within each test group (precision). Data were analyzed using 2-way ANOVA with the post hoc least significant difference test (α=.05). ResultsOverall trueness values were 19.1 μm (intraoral scanner group), 23.5 μm (desktop group), and 26.2 μm (PVS group), whereas overall precision values were 11.9 μm (intraoral), 18.0 μm (PVS), and 20.7 μm (desktop). Simple main effects analysis showed that impressions made with the intraoral scanner were significantly more accurate than those of the PVS and desktop groups when the TOC angle was less than 8 degrees (P<.05). Also, a statistically significant interaction was found between the effects of the type of impression and the TOC angle on the precision of single-tooth dental impressions (F=2.43, P=.002). Visual analysis revealed that the intraoral scanner group showed a homogeneous deviation pattern across all TOC angles tested, whereas scans from the PVS and desktop scanner groups showed marked local deviations when undercuts (negative angles) were present. ConclusionsConventional dental impressions alone or those further digitized with an extraoral digital scanner cannot reliably reproduce abutment tooth preparations when the TOC angle is close to 0 degrees. In contrast, digital impressions made with intraoral scanning can accurately record abutment tooth preparations independently of their geometry.

Clinical evaluation of an improved cementation technique for implant-supported restorations: a randomized controlled trial.

Cement remnants were frequently associated with peri-implantitis. Recently, a shoulderless abutment was proposed, raising some concern about cement excess removal. To compare different cementation techniques for implant-supported restorations assessing the amount of cement remnants in the peri-implant sulcus. Additional aim was to compare the effect of these cementation techniques using two different abutment designs. Forty-six patients requiring double implant-supported restoration in the posterior maxilla were randomly divided in two groups according to the cementation modality: intraoral and extraoral. According to the abutment finishing line, implants in each patient were randomly assigned to shoulderless or chamfer subgroup. In the intraoral group, crowns were directly seated onto the titanium abutment. In the extraoral group, crowns were firstly seated onto a resin abutment replica and immediately removed, then cleansed of the cement excess and finally seated on the titanium abutment. After cement setting, in both groups, cement excess was carefully tried to remove. Three months later, framework/abutment complexes were disconnected and prepared for microscopic analysis: surface occupied by exposed cement remnants and marginal gaps were measured. Additionally, crown/abutment complexes were grinded, and voids of cement were measured at abutment/crown interface. Related-samples Friedman's two-way analysis of variance by ranks was used to detect differences between groups and subgroups (P≤0.5). At the end of the study, a mean value of 0.45mm2 (±0.80), 0.38mm2 (±0.84), and 0.065mm2 (±0.13) and 0.07mm2 (±0.15) described surface occupied by cement remnants in shoulderless and chamfer abutment with intraoral cementation and shoulderless and chamfer abutment with extraoral cementation, respectively. A mean value of 0.40mm2 (±0.377), 0.41mm2 (±0.39) and 0.485mm2 (±0.47) and 0.477mm2 (±0.43) described cement voids at the abutment/crown interface; a mean value of 0.062mm (±0.03), 0.064mm (±0.35), 0.055mm (±0.016) and 0.054mm (±0.024) described marginal gaps. Statistics showed tendency of intraoral cementation to have significantly higher cement remnants compared with abutments with extraoral cementation groups. At the same time, the presence of voids was significantly higher in case of extraoral cementation. No significant differences between groups for the variable "gap". Despite the presence of more voids, extraoral cementation reduces cement excess. However, using low adhesivity cement and careful cement removal, a very limited quantity of cement remnants was observed also in the intraoral cementation.

A Prospective Study on Management of Mandibular Angle Fracture.

To evaluate the results of management of mandibular angle fracture by open reduction and internal fixation using single non compression miniplate via transbuccal, intraoral or extraoral approaches. In this prospective study, 30 patients were randomly selected regardless of age, sex requiring open reduction and internal fixation of non comminuted angle fracture with/or without other associated fractures of the mandible. All the patients were operated under general anaesthesia following routine haematological, biochemical, general physical examination and routine radiographic examination. Patients were randomly distributed into 3 groups namely: (1) intraoral, (2) transbuccal, and (3) extraoral groups depending on the surgical approach used for open reduction and internal fixation of fracture of the angle of mandible. In the intraoral group (12 patients), angle fracture was approached through the intraoral vestibular incision similar to sagittal split incision. In the transbuccal group (8 patients), angle fracture was approached through the intraoral vestibular incision and transbuccal stab incision for screw fixation via trochar. In the extraoral group (10 patients), angle fracture was approached through the Risdon's submandibular incision. In all the patients, fractures were reduced with upper and lower Erich's arch bar fixation as means for IMF intraoperatively. In all the patients, fracture of the angle of the mandible was fixed with single non compression 2.5mm, 4 holed with gap stainless steel miniplate and 6/8mm monocortical screws. All patients were followed up for minimum of 6months to maximum of 24months. Complications were relatively minor such as paresthesia (on average 26.7% first post-operative day which was gradually improved and on average after 1month was 3.3%), mild to moderate occlusal discrepancies (on average 36.7%) which needed the post-operative intermaxillary fixation with elastics for 1-2weeks, infection (20% on average) was mild to moderate which was managed with antibiotic therapy and/or incision and drainage except in one case, plate removal was done under general anaesthesia (extraoral group) because of recurrent infection. Post-operative pain was mild to moderate (mean VAS score pre operative-6.17, post-operative 1week-1.63) which was managed with analgesics. Mouth opening was recorded in all patients which was on average 20.98mm preoperatively which improved to 40.57mm after 1month. The use of a single non compression miniplate for fractures of the angle of the mandible is a simple, reliable technique with relatively rare major complications and few minor complications irrespective of the surgical approach used for the open reduction.

Mandibular Reconstruction Using a Tray With Particulate Cancellous Bone and Marrow and Platelet-Rich Plasma by an Intraoral Approach

To evaluate the possibility of immediate mandibular reconstruction using particulate cancellous bone and marrow (PCBM), platelet-rich plasma (PRP), and a tray, we compared the postsurgical infection rate and bone formation in patients who received mandibular reconstruction with this method using either an intraoral or extraoral approach. We conducted a retrospective study of a series of 18 patients who underwent the mandibular reconstruction procedure using a mesh tray with PCBM and PRP, all performed by 1 surgeon. These cases were further divided into those treated by the intraoral approach and those treated by the extraoral approach. Clinical data, postoperative bone formation, and complications in the 2 groups were evaluated. The χ(2) examination and the Mann-Whitney U test were used for statistical analysis. We could not detect any statistically significant differences in clinical data between the 2 groups, except for the timing of reconstruction. There were postoperative complications such as wound dehiscence and tray exposure, as well as infection of the reconstructed bone. The overall complication rate of the recipient sites in the intraoral group was 30% (3 of 10), whereas in the extraoral group, it was 0%. However, satisfactory bone formation was seen in all cases in the intraoral group (100% [10 of 10]) but only 87.5% (7 of 8) in the extraoral group. We conclude that mandibular reconstruction using a tray with PCBM and PRP is a safe and reliable method for cases of benign tumor and trauma, even if immediate reconstruction is performed by an intraoral approach.

In Vitro Biomechanical Comparison of the Effect of Pattern, Inclination, and Size of Positional Screws on Load Resistance for Bilateral Sagittal Split Osteotomy

The purpose of this in vitro investigation was to determine whether the pattern, angle of placement, or size of positional screws affected their ability to resist vertical loads resembling mastication in the bilateral sagittal split osteotomy system. Standardized bone substitutes were secured with three 12- to 16 mm-long, 1.85-, 2.0-, 2.1-, and 2.4-mm outer diameter, self-tapping titanium screws (Synthes, Solothurn, Switzerland) in various patterns using a positional screw technique. These patterns included transbuccal triangular, intraoral triangular, and transbuccal linear patterns. The models were secured in a jig and subjected to vertical loads by a mechanical testing unit (1475 UPM; Zwick, Ulm, Germany) until failure. Loading test data analysis was based on peak load values resulting in mechanical deformation of the system (1-, 3-, and 5-mm displacement), maximal force, and stiffness (load/displacement slope curve) for each group. Means and standard deviations were derived and compared for statistical significance using univariate analysis of variance with a confidence level of 95% (P values < .05). The designed study demonstrated that 1.85- and 2.0-mm-diameter positional screws provided similar stability in all 3 setups. Three screws placed in an inverted L pattern at 90° (simulating a transbuccal approach) showed significantly higher resistance to vertical forces for advancement movements at 1-, 3-, and 5-mm displacement when compared with the inverted L group of screws placed at an angle (intraoral approach) or 3 screws in a linear pattern placed at 90° (transbuccal approach) (P < .01). Under the conditions tested in this in vitro study, differences in the load resistance of positional screws placed in a transbuccal or intraoral approach could be demonstrated depending on the fixation technique. The transbuccal group of 3 screws in an inverted L pattern showed significantly greater stability than the intraoral group of 3 screws placed in an inverted L pattern and the transbuccal group of 3 screws in a linear pattern. Resistance to vertical loads with 1.85-mm screws was similar to that with the standard 2.0-mm screws in all 3 setups. The results of this study suggest that the angle of screw placement (surgical approach) and pattern have a greater influence on the stability of the bilateral sagittal split osteotomy system than the screw size.

Effects of temperature on blood flow in facial tissues

This study evaluated the effect of temperature on blood flow by using rubidium 86 to determine the fraction of cardiac output going to specific facial tissues of rats. Seventy-seven male Holtzman rats were divided into two groups and various subgroups. The intraoral subgroups were categorized according to the temperature of the water irrigating the oral cavity (11°, 39°, 41°, 43°, or 45°C). The extraoral subgroups were categorized according to whether heat or ice was applied to the cheek of the rats and the duration of application (10 or 20 minutes). Rats were killed within 60 seconds after injection of 86Rb, and tissue samples were taken from the buccal mucosa, facial skin, masseter muscle, mandible, tongue, and maxilla. The fraction of isotope uptake in each gram of these tissues (FU/g) was then calculated. For the intraoral group, the bath temperature of 39°C increased the FU/g in all tissues except masseter muscle and tongue. Higher bath temperature did not further alter the FU/g. Lowering the temperature to 11°C changed the FU/g significantly only in the tongue. For the extraoral group, 20-minute application of ice was required to reduce FU/g significantly in all tissues but masseter muscle and skin. Extraoral heat application for 10 minutes increased FU/g significantly in skin and tongue, but no further change was seen after 20 minutes of application.

Mandibular molar displacement secondary to the use of forces to retract the maxilla

Using previously described computer-aided techniques, we have been able to characterize quantitatively the displacements of the lower first molar associated with the use of several different therapeutic modalities that are conventionally employed to retract the maxilla in the treatment of Class II malocclusion. The total displacement of the molar has been partitioned into two components associated respectively with displacement of the entire mandible and with local interosseous migration (dental compensation) of the molar within the mandible. A further attempt has been made to partition treatment-associated effects from nontreatment-associated effects. While considerable variability in effect was observed within each sample on a case-by-case basis, some important normative trends did emerge. Contrary to our expectations, it was found that in each of the treatment groups, the mean local intraosseous rotational effect (Table 1113.2) was of greater magnitude than the mean effect of mandibular rotation (Table IIB.1). The character of the intraosseous rotation differed significantly ( P < 0.05) between the control group and each of the treatment groups. In the control group, a mean mesial crown tipping (that is, “proclination”) was noted. In each of the treatment groups, a mean distal crown tipping (“uprighting”) was noted. In both the cervical and intraoral groups, the lower molar tended to displace mesially more than in the control or high-pull groups. This mesial displacement derived from the mesial displacement of the mandible (Table IIC.3), rather than from displacement of the tooth within the bone (Table IICA). In both the high-pull and the intraoral groups, the lower molar erupted within the mandible significantly more than in the control and cervical groups (Table IIC.6). The statistically significant supereruption/extrusion of the upper molar in the cervical group (Table IIC.2) was not accompanied by an associated inhibition of the eruption of the lower first molar (Table IIC.6). In general, it seems reasonable to infer that the growth-related displacement of the mandible influenced the final position of the lower first molar more profoundly than did the treatment-associated displacement of the upper molar.

Quantitative analysis of the orthodontic and orthopedic effects of maxillary traction

This article analyzes differences in displacement of ANS and of the upper first molar when different vectors of force are delivered to the maxilla in non-full-banded Phase I mixed-dentition treatment of Class II malocclusion. The sample is identical to that for which we have previously reported differences in change in several key measures of mandibular and facial shape.14, 15 It includes a cervical-traction group, a high-pull-to-upper-molar group, a modified-activator group, and an untreated Class II control group. Using newly developed computer-conducted procedures, which are described, we have been able to partition the orthodontic and orthopedic components of upper molar displacement and also to isolate treatment effects from those attributable to spontaneous growth and development.In the region of ANS, small but statistically significant and clinically meaningful differences were noted between treatments. When the intercurrent effects of growth and development had been factored out (Table III), orthopedic distal displacement of ANS was significantly greater in the high-pull and cervical groups than in the activator group. Orthopedic downward displacement of ANS was seen to be significantly greater in the cervical group than in the high-pull and activator groups. In the region of the first molar cusp, mean distal displacement of the tooth as an orthopedic effect was found to be almost identical in the cervical and high-pull groups (although variability was greater in the cervical group), but the mean orthodontic effect was significantly greater in the high-pull group than in the cervical group. In the cervical group, where relatively light forces were used for relatively long treatment periods on average, more of the total distal displacement of the upper molar was of an orthopedic character than of an orthodontic character. Conversely, in the high-pull group, in which relatively heavier forces tended to be used for briefer treatment periods, most of the distal displacement at the upper molar was of an orthodontic character. These observations are contrary to expectations from conventional orthodontic theory. In the activator-treated group, roughly equal components of the treatment-associated distal displacement of the upper molar were of the orthodontic and orthopedic types. As concerns changes in the vertical direction in the region of the molar cusp, significant intrusion of both the orthopedic and orthodontic types was seen in the high-pull sample as compared to each of the other groups examined. The intraoral group also showed a tendency toward molar intrusion as compared to the untreated control group, but the trend did not reach statistical significance in this multiple-comparison test. The cervical-traction group showed significant mean extrusive effects of both the orthodontic and the orthopedic types, but even for this group total extrusion was on average no more than 1 mm. as compared to the control group.