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ABSTRACT Background: Short implants (≤8 mm) are manufactured for use in atrophic regions of the jaws. As implant length in many studies has been proven to play a major role in implant survival it is indicated to evaluate survival of short implants in the present literature. Purpose: The purpose of this study was systematically to evaluate publications concerning short dental implants defined as an implant with a length of ≤8 mm installed in the maxilla or in the mandible with special reference to implant type, survival rate, location of implant site, and observation time. Materials and Methods: A Medline and a hand search were conducted to identify studies concerning short dental implants of length ≤8 mm published between 1992 and October 2009. The articles included in this study report data on implant length ≤8 mm, implant surface, registered region of installment, observation time, single tooth restorations, supporting overdentures, splinted implants, and implants used for prostheses. Results: The 27 included studies represent zero randomized clinical trial studies, 15 prospective nonrandomized, noncontrolled clinical trials, 11 retrospective nonrandomized, noncontrolled clinical trials, and one review. Data on 6-mm implants were few and most frequent represented was manufactured Straumann implants representing 441 out of 549 implants. Brånemark implants, 7 mm in length, comprised 1607 implants out of 1808. Straumann implants, 8 mm in length, comprised 2040 out of 2352 implants. Failures varied between 0 and 14.5%, 0 and 37.5% and 0 and 22.9% of the 6-, 7-, and 8-mm-long implants, respectively. Conclusion: Short implant length was not related to observation time, installment region, failures, and dropouts were not specified, subsequently a meta-analysis was not possible to perform. [ABSTRACT FROM AUTHOR]

The literature lacks a reliable holistic approach for the three-dimensional (3D) assessment of the temporomandibular joint (TMJ) including all three adaptive processes, which are believed to contribute to the position of the mandible: (1) adaptive condylar changes, (2) glenoid fossa changes, and (3) condylar positional changes within the fossa. Hence, the purpose of the present study was to propose and assess the reliability of a semi-automatic approach for a 3D assessment of the TMJ from cone-beam computed tomography (CBCT) following orthognathic surgery. The TMJs were 3D reconstructed from a pair of superimposed pre- and postoperative (two years) CBCT scans, and spatially divided into sub-regions. The changes in the TMJ were calculated and quantified by morphovolumetrical measurements. To evaluate the reliability, intra-class correlation coefficients (ICC) were calculated at a 95% confidence interval on the measurements of two observers. The approach was deemed reliable if the ICC was good (>0.60). Pre- and postoperative CBCT scans of ten subjects (nine female; one male; mean age 25.6 years) with class II malocclusion and maxillomandibular retrognathia, who underwent bimaxillary surgery, were assessed. The inter-observer reliability of the measurements on the sample of the twenty TMJs was good to excellent, ICC range (0.71–1.00). The range of the mean absolute difference of the repeated inter-observer condylar volumetric and distance measurements, glenoid fossa surface distance measurements, and change in minimum joint space distance measurements were (1.68% (1.58)–5.01% (3.85)), (0.09 mm (0.12)–0.25 mm (0.46)), (0.05 mm (0.05)–0.08 mm (0.06)) and (0.12 mm (0.09)–0.19 mm (0.18)), respectively. The proposed semi-automatic approach demonstrated good to excellent reliability for the holistic 3D assessment of the TMJ including all three adaptive processes. [ABSTRACT FROM AUTHOR]

The purpose of the study was to examine if Bio-Oss initiated osteoinduction or osteoconduction when implanted into rats. Sintered and unsintered granules of the anorganic bovine bone Bio-Oss was implanted subperiosteally for alveolar ridge augmentation purposes and heterotopically in the abdominal muscles of rats. Light microscopic evaluation revealed no osteoinduction or osteoconduction in connection with sintered or unsintered Bio-Oss. A foreign body reaction was observed around both forms. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine if increased bony ingrowth developed when hydroxylapatite was implanted together with an osteoinductive substrate. Dense hydroxylapatite granules (HA) (Calcitite, Calcitek, San Diego, CA, USA) were mixed with equal volumes of allogenic, demineralized, Iyophilized dentin or bone and implanted subperiosteally for alveolar ridge augmentation purposes and heterotopically in the abdominal muscles in rats. Light microscopic evaluation revealed that HA was surrounded by fibrous connective tissue containing foreign body giant cells and it had neither an osteoinductive nor an oscteoconductive effect. The newly formed bone induced from the implanted allogenic, demineralized, lyophilized dentin or bone was never found in close contact with the HA and did not incorporate the implant. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate bone substitutes for alveolar ridge augmentation by osteoinduction. Allogenic, demineralized, and lyophilized dentin and bone was tested for osteoinductive properties in order to establish an experimental model for further studies. Implantations were performed subperiosteally on the premaxilla and heterotopically in the abdominal muscles of rats. Light microscopic evaluations revealed that all allogenic, demineralized, and lyophilized dentin and bone implants induced new bore formation. No inflammatory or foreign body reactions were observed. [ABSTRACT FROM AUTHOR]

The present study describes the use of a degradable and a non-degradable material for guided bone regeneration. Forty rabbits were divided into 5 groups. Bicortical defects 15 mm in diameter were prepared in rabbit calvaria. A titanium microplate was placed over the defect to prevent collapse of the membrane. The calvarial defects of 2 groups were covered by an outer expanded polytetrafluoroethylene (e-FTFE) membrane respectively by a Polyglactin 910 membrane. Bicortical e-PTFE membranes or Polyglactin 910 membranes were used in 2 other groups. The defects were not covered by membranes in the control group. Undecalcified sections were prepared for histologic evaluation after an observation period of 8 weeks. Complete bone healing of the defects was not observed in any of the specimens. The Polyglactin 910 material lacks physical strength, resulting in collapse of the membrane and brain tissue hemiation into the defects. Subsequently, bone regeneration was impaired. The cellular reactions due to degradation of the material were minor and did not interfere with bone healing. Defects covered bicortically by e-PTFE membranes revealed the largest amount of regenerated bone. The e-PTFE membrane induced a severe cellular reaction, but no inhibition of bone regeneration was noted. [ABSTRACT FROM AUTHOR]

The present study describes the use of unbiased stereological methods for the quantitative evaluation of the amount of regenerated bone. Using the principle of guided bone regeneration the amount of regenerated bone after placement of degradable or non-degradable membranes covering defects in rabbit calvaria was compared. Forty rabbits were divided into 5 groups. A titanium microplate was placed over the defect to prevent collapse of the membrane. The non-degradable expanded polytetrafluoroethylene membrane and the degradable Polyglactin 910 material were both placed unicortically and bicortically. Undecalcified sections were prepared for stereologic evaluation after an observation period of 8 weeks. Complete bone healing of the defects was not observed in any of the specimens. Unbiased stereologic estimates revealed 48% bone regeneration in defects covered by 2 e-PTFE membranes, and 12% in defects covered by 2 Polyglactin 910 membranes. Defects covered by 1 e-PTFE or Polyglactin 910 membranes revealed 10% or 18% bone regeneration, respectively. The control group regenerated 14%. The major difference of the estimates was caused by real difference between specimens, i.e. biologic variation, whereas only minimal variance was added by the stereologic estimation procedure. [ABSTRACT FROM AUTHOR]

Background and Objectives: Patients with dentofacial deformity (DFD) requiring orthognathic treatment have poor aesthetics, jaw function and psychological well‐being, which potentially affect the quality of life. This study aimed to investigate the health‐related general, oral and orthognathic quality of life, jaw function and sleep‐disordered breathing at different stages of orthognathic surgical treatment. Methods: A total of 120 consecutive patients with DFD were recruited and grouped as pre‐orthodontic treatment (group 1), pre‐surgery (group 2), 4 months post‐surgery (group 3), 24 months post‐surgery (group 4) and in addition 30 controls without DFD (group 0). Outcomes were assessed using general health Short Form Survey (SF‐36), Oral Health Impact (OHIP‐14), Orthognathic Quality of Life Questionnaire (OQLQ), STOP‐Bang and Jaw Function Limitation Scale (JFLS) questionnaires. In addition, presence or absence of pain was recorded. Data were tested with analysis of variance, Kruskal–Wallis test, Tukey post hoc test and structural equation modelling (SEM). Results: Results revealed SF‐36 (p =.814) and STOP‐Bang (p =.143) total scores did not differ between control and treatment groups. In contrast, OHIP‐14, OQLQ and JFLS total scores differed between groups (p =.001). Higher scores were observed in groups 1 (p =.001), 2 (p =.001) and 3 (p =.041) compared to group 0, indicating poor oral health in patients with DFD. Importantly, in group 4, oral health‐related quality of life was better, and OHIP‐14 (p =.936) and JFLS (p =.572) scores did not differ from controls. OQLQ scores of group 4 were significantly lower than group 1 (p =.001) but higher than group 0 (p =.013). SEM results revealed a significant negative associations of pain with JFLS and OQLQ; OHIP‐14 with OQLQ; OHIP‐14 with SF‐36; and finally STOP‐Bang with SF‐36. Positive associations were observed between JFLS and OHIP‐14; OHIP‐14 and OQLQ. Conclusion: Oral health‐related quality of life and jaw function appears to be improved 24 months after orthognathic surgery. Pain and limitation in jaw function had a negative association with health‐related quality of life. [ABSTRACT FROM AUTHOR]

Background and objective: Patients with dentofacial deformity often present with impaired masticatory function, orofacial pain and temporomandibular disorders (TMD). This study investigates the relationship between TMD, pain, jaw and masticatory function at different stages of orthognathic surgical (OS) treatment. Methods: A total of 120 OS patients were prospectively recruited and grouped as pre‐orthodontic (group 1), pre‐surgery (group 2), 4‐month post‐surgery (group 3), 24‐month post‐surgery (group 4), in addition to 30 controls (group 0). Outcomes were assessed using: Jaw Function Limitation Scale (JFLS), McGill pain questionnaire, DC/TMD instrument, voluntary maximum bite force (MVBF), and masticatory efficiency (ME) using two‐coloured chewing gum. Data were analysed using structural equation modelling. Results: The prevalence of non‐painful TMD did not differ between groups (p =.827). However, the prevalence of painful TMD differed between groups (p =.001). Among the painful TMDs, the highest prevalence was observed for masseter myalgia in group 2 (p =.031), and importantly group 4 did not differ from group 0 (p =.948). The MPQ score was significantly higher in group 1 (p =.001) compared to group 0, and the JFLS score was significantly higher in groups 1, 2 and 3 compared to group 0. Notably, MPQ (p =.756) and JFLS (p =.572) scores in group 4 were not different from group 0. However, MVBF (p =.996) and ME (p =.991) did not differ between groups 1 and 4. The association of self‐reported pain and jaw function with the masticatory function was observed in OS patients. Conclusion: OS was not associated with a negative impact on TMD. Jaw function and pain levels were similar to controls at the 24‐month follow‐up. The masticatory function was further affected by the surgery and seems to require a longer recovery time. Moreover, it was confirmed that pain and TMD were associated with limitations in jaw function and impacts on masticatory function. [ABSTRACT FROM AUTHOR]

This systematic review aimed to determine the accuracy/stability of patient-specific osteosynthesis (PSI) in orthognathic surgery according to three-dimensional (3D) outcome analysis and in comparison to conventional osteosynthesis and computer-aided designed and manufactured (CAD/CAM) splints or wafers. The PRISMA guidelines were followed and six academic databases and Google Scholar were searched. Records reporting 3D accuracy/stability measurements of bony segments fixated with PSI were included. Of 485 initial records, 21 met the eligibility (566 subjects), nine of which also qualified for a meta-analysis (164 subjects). Six studies had a high risk of bias (29%), and the rest were of low or moderate risk. Procedures comprised either single-piece or segmental Le Fort I and/or mandibular osteotomy and/or genioplasty. A stratified meta-analysis including 115 subjects with single-piece Le Fort I PSI showed that the largest absolute mean deviations were 0.5 mm antero-posteriorly and 0.65° in pitch. PSIs were up to 0.85 mm and 2.35° more accurate than conventional osteosynthesis with CAD/CAM splint or wafer (p < 0.0001). However, the clinical relevance of the improved accuracy has not been shown. The literature on PSI for multi-piece Le Fort I, mandibular osteotomies and genioplasty procedure is characterized by high methodological heterogeneity and a lack of randomized controlled trials. The literature is lacking on the 3D stability of bony segments fixated with PSI. [ABSTRACT FROM AUTHOR]

Background Biomaterials are commonly used to augment the maxillary sinus floor prior to or in conjunction with dental implant installation. Recently, porous titanium granules ( PTGs) have been used in oral implant surgery to stabilize implants and function as an osteoconductive matrix. Purpose To evaluate if PTGs can be safely used in a larger population of patients, treated by different surgeons, when sinus floor augmentation was required in conjunction with implant installation. The primary endpoint was 12-month survival rate of the dental implants. Biopsies for histology were taken from the augmented area. Materials and Methods At five centers, 40 subjects with uni or bilateral posterior edentulism and atrophy of the posterior maxilla (3-6 mm) were enrolled. In a single-stage procedure, PTG and one to three dental implants were installed in each quadrant. In total, 70 implants were included in the study. Results One immobile implant was removed. The mean marginal bone loss was 0.5 mm and 0.8 mm, on the mesial and distal side, respectively. Histologically, all biopsies demonstrated bone ingrowth. Conclusions The results suggest that PTG can be safely and effectively used as augmentation material in the sinus floor when used with dental implants in a one-stage procedure. [ABSTRACT FROM AUTHOR]

We studied the association between bisphosphonate use and risk of atrial fibrillation or flutter and the effect of confounders such as heart and lung disease in a nationwide retrospective cohort from Denmark. All users of bisphosphonates and other drugs against osteoporosis between 1996 and 2006 ( n = 103,562) were the exposed group and three age- and gender-matched controls from the general population ( n = 310,683) were the nonexposed group. The main outcome measure was atrial fibrillation or atrial flutter. Before initiation of treatment against osteoporosis, no excess of atrial fibrillation or flutter was present for any drug except for etidronate (OR = 1.22, 95% CI 1.15–1.29). After initiation of treatment, raloxifene was not associated with any excess risk of atrial fibrillation (OR = 0.98, 95% CI 0.72–1.33). Etidronate (HR = 1.08, 95% CI 1.02–1.14) and alendronate (HR = 1.09, 95% CI 1.00–1.20) were associated with an excess risk of atrial fibrillation after treatment start if statistical adjustments were made for cardiovascular disease. However, this association disappeared upon statistical adjustment for chronic obstructive pulmonary disease (COPD) (etidronate HR = 1.04, 95% CI 0.98–1.10; alendronate HR = 1.05, 95% CI 0.96–1.15). In patients using etidronate (12.5% vs. 3.8%) and alendronate (11.4% vs. 4.6%) major differences were present in prevalence of COPD at start of treatment compared to matched controls. In conclusion, oral bisphosphonates do not seem to be associated with an excess risk of atrial fibrillation. Any excess risk seen in prior studies may be due to confounding from COPD. [ABSTRACT FROM AUTHOR]

Prior studies have indicated an excess risk of gastroduodenal ulcers and esophagus perforations with the use of bisphosphonates. However, little is known about the contribution of comorbid conditions and concomitant drug use on this risk. We studied the risk of esophagus and gastric events in patients on a wide range of drugs against osteoporosis both before and after initiation of these drugs. We studied a nationwide register-based cohort from Denmark with all users of drugs against osteoporosis between 1996 and 2006 ( n = 103,562) as cases and three age- and sex-matched controls from the general population ( n = 310,683). In a crude analysis, most drugs were already associated with an increased risk of esophagitis, esophageal ulcerations, or esophageal perforations or gastroduodenal ulcers before initiation of the drugs. Upon adjustment, this excess risk disappeared for most drugs except parathyroid hormone and its analogues, etidronate and clodronate. Only for etidronate, alendronate, and raloxifene were sufficient data present for events after initiation of the drugs, and for these, an increased risk was present for all events except gastroduodenal ulcers with raloxifene. Several drugs against osteoporosis are associated with an increased risk of esophagitis, esophageal ulcers, esophageal perforation, and gastroduodenal ulcers. However, the increase was already present before initiation of the drug for several types of drugs against osteoporosis. This points at an effect of the underlying condition being treated or comorbid conditions and drugs being provided in patients with osteoporosis, such as nonsteroidal anti-inflammatory drugs and corticosteroids. [ABSTRACT FROM AUTHOR]

The effect of recombinant human platelet-derived growth factor-BB (rhPDGF-BB) on bone healing was examined in calvarial defects in rabbits. Bicortical circular (critical size) defects were prepared in the calvarial bone of 16 rabbits. The defects were closed on the dural side and covered externally with expanded polytetrafluoroethylene membranes to prevent interference with osteogenesis within the defect by the surrounding tissue and to keep the growth factor in place. A single dose of methylcellulose gel (4.4%) with (n=8) or without rhPDGF-BB (50 μg/ml) (n = 8) was applied to the defects, and the bone formation was evaluated after 8 weeks. Healing of defects in both groups was characterized by the presence of newly formed bone along the edges of the original defect and by a central area of fibrous connective tissue. The newly formed bone in the rhPDGF-BB treated defects had a trabecular structure: in contrast, a more compact structure was found in the control defects. In the rhPDGF-BB-treated defects, the bone ingrowth was 51.8 ± 7.1% compared to 30.5 ± 3.3% in the control defects. Furthermore, the amount of mineralized tissue was increased 112% in the rhPDGF-BB group. The amount of bone marrow was increased 75% in the rhPDGF-BB-treated defect. The porosity of cortical lamella in the newly formed bone was 84% higher in the rhPDGF-BB- treated defects compared to the control. These results show that administration of a single dose of rhPDGF-BB stimulates bone formation in critical size calvarial defects. [ABSTRACT FROM AUTHOR]