Transverse molar movements during growth

The purpose of this study was to evaluate changes in molar crown torque and intermolar arch width from the time of permanent first molar eruption to early adulthood. Molar crown torque and intermolar arch width were measured in 36 untreated subjects with Class I occlusion from the Iowa Facial Growth Study at approximate ages 7.5, 10.3, 12.9, 16.5, and 26.4 years. On average, the mandibular first and second molars uprighted buccally by 5.0 degrees and 7.5 degrees, respectively. Mandibular first and second molar intermolar width increased by 2.2 and 0.78 mm, respectively. On average, maxillary first and second molars uprighted lingually by 3.3 degrees and 5.9 degrees, respectively. Maxillary first and second intermolar width increased by 2.8 and 2.0 mm, respectively. Results of statistical analysis by the Wilcoxon signed rank test indicate that (1) maxillary molars erupt with buccal crown torque and upright with age, whereas mandibular molars erupt with lingual crown torque and upright with age (P <.01), and (2) molar crown torque changes are accompanied by concurrent increases in maxillary and mandibular intermolar width (P <.01).     

The Role of Abutment-Attachment Selection in Resolving Inadequate Interarch Distance: A Clinical Report

A critical factor that needs to be evaluated during the diagnosis and treatment planning phase for patients seeking an implant-tissue-supported overdenture or metal-resin implant fixed denture is the presence of adequate interarch distance. The amount of interarch distance is critical to the selection of appropriate implant abutments and attachments for both implant-tissue-supported overdentures and metal-resin implant fixed complete dentures. This clinical report describes a patient with complications related to the failure to diagnose inadequate interarch distance, and the methods used to resolve the patient's chief complaint. A guide for abutment-attachment selection using one commercially available implant system is given.     

Can nonstandardized bitewing radiographs be used to assess the presence of alveolar bone loss in epidemiologic studies?

OBJECTIVE: To compare periodontitis-associated alveolar bone loss assessment by standardized and nonstandardized radiographs in clinical and epidemiologic studies. METHODS: Participants included 37 patients aged 21-66 years with prior nonstandardized bitewing radiographs scheduled to receive bitewing radiographs as part of their next routine dental care visit. Standardized bitewing radiographs were taken with a Rinn film holder to position the film in the mouth and align the X-rays so that they were at 90 degrees to the film. Before taking the radiograph the bite was registered in centric relation using a polyether impression material. One registered dental hygienist took and processed all the standardized radiographs. One dentist read all radiographs using a viewing box, magnifying lens, and periodontal probe with William's markings. Radiographic bone loss was measured to the closest millimeter at mesial and distal sites of the posterior teeth excluding third molars. The examining dentist was blinded to the participant's name, age, gender, or if the radiograph was standardized or nonstandardized. RESULTS: Mean bone loss (+/- SD) was similar in the standardized and nonstandardized groups (1.60 +/- 0.72 mm versus 1.64 +/- 0.85 mm), and the correlation was high (r = 0.95). Periodontitis was defined as present if the participant had at least one site with 3, 4 and 5 mm bone loss. The Kappa statistics for concordance using these three cutoffs were good and ranged from 0.60 to 0.65. The sensitivity ranged from 72.7 to 80.8% and specificity from 88.5 to 90.9%. CONCLUSIONS: Periodontitis assessed as mean alveolar bone loss or the prevalence of disease based on alveolar bone loss can be accurately and reliably evaluated from nonstandardized radiographs.     

Validity of radiographic evaluations of bone formation in a rat calvaria osteotomy defect model

OBJECTIVE: The objective of this study was to evaluate the validity of radiographic evaluations of bone formation in a critical-size rat calvaria osteotomy defect model. METHODS: Bilateral, critical-size ( [symbol in text] 6 mm) calvaria osteotomy defects in 30 adult Sprague-Dawley rats treated with a rat platelet-rich plasma preparation or control treatments were evaluated by radiographic and histometric measures following a 4- or 8-week healing interval. Standardized radiographic images of the rat calvaria gross specimens were used to assess bone formation within the defect sites by visual evaluation of the grey scale by three masked examiners. The most central portion of each defect site was subject to histometric analysis using a PC-based image analysis system. Kappa statistics and percentage agreement between the radiographic and histometric analysis were estimated. RESULTS: Radiographic evaluations of bone formation are associated with significant weaknesses poorly representing actual healing events; kappa statistics (0.17) denoting slight agreement beyond chance. Perfect agreement between the histologic and radiographic analysis for defect sites showing complete and partial histologic bone fill was achieved 63% and 50% of the time, respectively. Agreement reached only 20% for sites with no/limited bone fill. When no/limited and partial bone fill occurred, the radiographic analysis tended to overestimate bone fill and underestimate bone fill when complete closure of the defect sites was observed in the histologic analysis. CONCLUSION: Low accuracy was observed when radiographic evaluations were employed in identifying and characterizing bone fill in the rat calvaria osteotomy defects. Assessment of bone healing in animal models aiming at treatment recommendations for clinical application must not solely be based on radiographic analysis, but should be confirmed using histologic observations.     

Temporalis myofascial flap in maxillofacial reconstruction: clinical and histological studies of the oral healing process

Objectives—To report our experience with temporalis myofascial flaps (TMF), describe the healing process of uncovered flaps in the mouth, and the histology of the repaired mucosa in the long term. Design—Prospective clinical and histological study. Subjects—36 patients who received a TMF over a 6.5 year period for serial assessment of the oral healing, 24 patients whose scars over the reconstructed area were assessed clinically, and 11 whose repaired mucosa was assessed histologically. Main outcome measures—To follow the clinical process of oral healing of the TMF and describe the repaired mucosa healed over the flap. Results—The uncovered TMF in the mouth healed gradually starting with an acute inflammatory phase, going through chronic inflammatory and proliferative phases with eventual epithelialisation of the oral mucosa. There were no major complications. The healed mucosa showed mild scarring in 70% of cases and the repaired mucosa had characteristic histological features that were distinct from the normal mucosa. Conclusion—The TMF is an extremely reliable and versatile flap for maxillofacial reconstruction which heals gradually with eventual coverage by mildly scarred repaired mucosa.     

Prosthodontic procedures for implant reconstruction. 1. Diagnostic procedures

The University of Sydney Dental School and more recently the Implant Centre have been treating patients with the Brånemark Osseointegration Implant System since 1981. Success depends on close cooperation between surgeon and prosthodontist. This paper describes specific prosthodontic treatment planning procedures based on a general knowledge of prosthodontics, and detailed methods for determining the position, length and alignments of the implants for a specific case by the use of radiographic and surgical templates.     

Comparing the Impact of Oral Disease in Two Populations of Older Adults: Application of the Geriatric Oral Health Assessment Index

Objectives : This study compares the distributional and psychometric properties of the Geriatric Oral Health Assessment Index (GOHAI) in two samples of older adults, and examines how the self-perceived impact of oral disease, as measured by the GOHAI, varies in accordance with sample sociodemographic and health characteristics. Methods : Results are based on survey data from two samples of older men: a Medicare sample of patients using community physicians (n=799; mean age=74) and users of VA ambulatory health care (n=542; mean age=72). Results : The findings indicated significant differences between samples in mean GOHAI scores, with the VA sample exhibiting worse scores. A number of similarities in psychometric properties of the instrument across the two samples were found: high internal consistency reliability and similar inter-item and item-scale correlations. Factor analyses revealed somewhat different structures between the two samples, but explained similar amounts of variance; regression analyses indicated that income and self-rated oral health were significant predictors of GOHAI scores in both samples. Conclusions : The GOHAI exhibits satisfactory psychometric properties in both samples and is sensitive to sociodemographic differences among and between two samples of older men. Results suggest continued use of the GOHAI as an indicator of the impact of oral conditions on functioning and well-being in a variety of samples.