Clinical Factors Affecting the Accuracy of Guided Implant Surgery-A Systematic Review and Meta-analysis.

OBJECTIVES: To systematically review the current dental literature regarding clinical accuracy of guided implant surgery and to analyze the involved clinical factors. MATERIAL AND METHODS: PubMed and Cochrane Central Register of Controlled Trials were searched. Meta-analysis and meta-regression analysis were performed. Clinical studies with the following outcome measurements were included: (1) angle deviation, (2) deviation at the entry point, and (3) deviation at the apex. The involved clinical factors were further evaluated. RESULTS: Fourteen clinical studies from 1951 articles initially identified met the inclusion criteria. Meta-regression analysis revealed a mean deviation at the entry point of 1.25 mm (95% confidence interval [CI]: 1.22-1.29), 1.57 mm (95% CI: 1.53-1.62) at the apex, and 4.1° in angle (95% CI: 3.97-4.23). A statistically significant difference (P < .001) was observed in angular deviations between the maxilla and mandible. Partially guided surgery showed a statistically significant greater deviation in angle (P < .001), at the entry point (P < .001), and at the apex (P < .001) compared with totally guided surgery. The outcome of guided surgery with flapless approach indicated significantly more accuracy in angle (P < .001), at the entry point (P < .001), and at apex (P < .001). Significant differences were observed in angular deviation based on the use of fixation screw (P < .001). CONCLUSIONS: The position of guide, guide fixation, type of guide, and flap approach could influence the accuracy of computer-aided implant surgery. A totally guided system using fixation screws with a flapless protocol demonstrated the greatest accuracy. Future clinical research should use a standardized measurement technique for improved accuracy.

Bone quality evaluation: comparison of cone beam computed tomography and subjective surgical assessment.

PURPOSE: To examine the relationship between dental cone beam computed tomography (CBCT) gray scale values and Hounsfield units (HU), and whether the gray values of edentulous sites correlate with the subjective clinical bone quality assessed at surgery. MATERIALS AND METHODS: Two radiographic phantoms containing varying concentrations of either dipotassium hydrogen phosphate or calcium hydroxyapatite (HA) were imaged using multislice CT or CBCT. Reconstructed DICOM data were analyzed to examine the relationship between CBCT gray values and HU. Presurgical CBCT scans from 52 patients who underwent implant placement in the posterior sextants were used. The gray values of the edentulous implant sites were measured and compared with the subjective bone quality assessed at surgery. RESULTS: There was a strong correlation between CBCT gray values and HU. CBCT gray values increased linearly with increasing calcium HA or bone equivalent density material. CBCT gray values measured at edentulous implant sites ranged from -455 to 642, with a trend of decreasing gray values with bone quality type. The median gray values for the four subjective bone types were: 362 (type 1), 214 (type 2), 76 (type 3), and -454 (type 4). CONCLUSIONS: CBCT gray values can be used to infer bone density and may provide a valuable aid to predict bone quality at potential implant sites.

Bisphosphonate-associated osteonecrosis of the jaw: report of a task force of the American Society for Bone and Mineral Research.

UNLABELLED: ONJ has been increasingly suspected to be a potential complication of bisphosphonate therapy in recent years. Thus, the ASBMR leadership appointed a multidisciplinary task force to address key questions related to case definition, epidemiology, risk factors, diagnostic imaging, clinical management, and future areas for research related to the disorder. This report summarizes the findings and recommendations of the task force. INTRODUCTION: The increasing recognition that use of bisphosphonates may be associated with osteonecrosis of the jaw (ONJ) led the leadership of the American Society for Bone and Mineral Research (ASBMR) to appoint a task force to address a number of key questions related to this disorder. MATERIALS AND METHODS: A multidisciplinary expert group reviewed all pertinent published data on bisphosphonate-associated ONJ. Food and Drug Administration drug adverse event reports were also reviewed. RESULTS AND CONCLUSIONS: A case definition was developed so that subsequent studies could report on the same condition. The task force defined ONJ as the presence of exposed bone in the maxillofacial region that did not heal within 8 wk after identification by a health care provider. Based on review of both published and unpublished data, the risk of ONJ associated with oral bisphosphonate therapy for osteoporosis seems to be low, estimated between 1 in 10,000 and <1 in 100,000 patient-treatment years. However, the task force recognized that information on incidence of ONJ is rapidly evolving and that the true incidence may be higher. The risk of ONJ in patients with cancer treated with high doses of intravenous bisphosphonates is clearly higher, in the range of 1-10 per 100 patients (depending on duration of therapy). In the future, improved diagnostic imaging modalities, such as optical coherence tomography or MRI combined with contrast agents and the manipulation of image planes, may identify patients at preclinical or early stages of the disease. Management is largely supportive. A research agenda aimed at filling the considerable gaps in knowledge regarding this disorder was also outlined.

A review of the association between osteoporosis and alveolar ridge augmentation.

OBJECTIVE: Because of increasing life expectancy and popularity of dental implants, surgeons face a larger number of osteoporotic patients who require bone augmentation. Relationship between low bone density/osteoporosis and bone graft success is still not clear. The purpose of this article is to review and summarize the literature regarding the success of alveolar bone augmentation in osteoporosis. STUDY DESIGN: The study design includes a literature review of relevant preclinical and clinical articles that address the association between osteoporosis and alveolar bone augmentation. RESULTS: Increased rate of complications such as resorption of bone graft, non-integration of bone graft, delayed healing time, and implant failure in augmented bone especially in the maxilla may be associated with compromised bone health. CONCLUSIONS: Despite the decreased success rate, osteoporosis is not an absolute contraindication for bone augmentation and dental implant placement. The modifiable risk factors for osteoporosis should be eliminated before surgery.

The effect of orthognathic surgery on taste function on the palate and tongue.

PURPOSE: Perceived taste intensity and taste quality identification on localized regions of the palate and tongue were examined for 9 patients before orthognathic surgery and again at 1 to 2 and 6 to 9 months after surgery. Taste function would be at risk on the palate after maxillary Le Fort I osteotomy (LFI) and on the tongue after mandibular sagittal split osteotomy (SSO) because of potential damage to peripheral nerves conducting afferent chemosensory information from these regions. PATIENTS AND METHODS: Three patients had LFI and SSO, 1 had LFI only, and 5 had SSO only. Patients rated taste intensity (using a 10-point fixed-interval scale) and identified taste quality of 4 solutions (NaCl, sucrose, citric acid, and quinine.HCl) brushed with a cotton-tipped applicator on each of 6 oral locations (left and right soft palate, left and right anterior and posterolateral tongue). RESULTS: Perceived taste intensity of NaCl, sucrose, and citric acid was reduced on average to 34% of presurgery values on the palate for patients who underwent LFI, but the taste intensity of quinine was not affected. LFI also affected the ability to correctly identify the quality of tastants applied to the palate: Patients made 38% correct quality identifications postsurgery compared with 91% presurgery. Perceived taste intensity of quinine.HCl placed on the tongue was reduced to 72% of its presurgery value after SSO, but the taste intensities of NaCl, sucrose, and citric acid were not affected. Correct quality identifications of sucrose, citric acid, and quinine.HCl were reduced to 75% at 2 months post-SSO compared with 96% presurgery and at 6 months postsurgery, but identification for NaCl was 96% before and after surgery. CONCLUSION: In the patients studied, taste function on the palate was significantly decreased for 6 to 9 months after LFI, likely a result of impairment of function of the greater superficial petrosal branch of the facial nerve. Lingual taste function, reduced at 1 to 2 months after SSO, likely due to impaired chorda tympani nerve function, improved by 6 to 9 months. Palatal and lingual neurosensory testing can be used to identify reversible sequelae of oral maxillofacial surgery.

Recovery after third molar surgery: clinical and health-related quality of life outcomes.

PURPOSE: The study goal was to assess both clinical and health-related quality of life (HRQOL) outcomes after third molar surgery. METHODS: Patients who were having 4 third molars removed were enrolled in a prospective clinical trial. Baseline data were recorded that included demographics, the patient's and surgeon's assessment of third molar conditions, and details of the surgical procedure. After surgery, clinical data were collected that detailed healing and any treatment that was rendered. Each patient was given an HRQOL instrument to complete on each postsurgery day for 14 days; the instrument was designed to assess a patient's perception of recovery in 4 main categories: pain, lifestyle, oral function, and other symptoms related to the procedure. RESULTS: Recovery data were available for 630 of 740 enrolled patients. The median age of the 630 patients was 21 years, and the median operation time was 30 minutes. Recovery for most HRQOL measures occurred within 5 days after surgery. However, recovery from pain to the criterion of "little or none" was delayed relative to other HRQOL measures. Twenty-two percent of patients were treated for delayed healing after surgery. CONCLUSIONS: Having both clinical and HRQOL data on recovery after third molar surgery could assist the surgeon when informing prospective patients about what to expect after surgery to remove third molars.