A cadaveric study of maxillary sinus size as an aid in bone grafting of the maxillary sinus floor

Simulation of sinus floor augmentation with symphysis bone graft using three-dimensional computerized tomography

The objective of this study was to evaluate the maximum amount of harvestable bone graft in the mandibular symphysis and the augmentation volume needed for different sinus lift levels (from 10 to 18 mm), in addition to calculating which sinus lift level can be acquired using the individual's symphysis bone graft volume with three-dimensional computerized tomography (3D CT) and software. Data from 15 CT scans was obtained from 15 adult patients (10 males, five females). The CT data, in DICOM format, was read into Mimics software from Materialize (Leuven, Belgium), with a slice thickness of 0.5 mm. The mandibular symphysis bone graft volumes and different levels of sinus lift augmentation volumes were calculated on the 3D images using Mimics software. It was determined that the average symphysis bone volume (3491.08+/-772.12 mm(3)) could provide approximately 14 mm of sinus lift height (3167.84+/-1067.65). 3D CT techniques and software can be used to calculate the required graft volume for sinus floor augmentation and symphysis bone graft volume, and the mandibular symphysis region can provide adequate bone volume for sinus lift augmentation.

Spiral computed tomography based maxillary sinus imaging in relation to tooth loss, implant placement and potential grafting procedure

Objectives

The purpose of the present study was to explore the maxillary sinus anatomy, its variations and volume in patients with a need for maxillary implant placement.

Material and Methods

Maxillary sinus data of 101 consecutive patients who underwent spiral computed tomography (CT) scans for preoperative implant planning in the maxilla at the Department of Periodontology, University Hospital, Catholic University of Leuven, Leuven, Belgium were retrospectively evaluated. The alveolar bone height was measured on serial cross-sectional images between alveolar crest and sinus floor, parallel to the tooth axis. In order to describe the size of the maxillary sinus anteroposterior (AP) and mediolateral (ML) diameters of the sinus were measured.

Results

The results indicated that the alveolar bone height was significantly higher in the premolar regions in comparison to the molar region (n = 46, P < 0.01). The age showed negative relation to bone dimension (r = - 0.32, P = 0.04).

Anterior and posterior border of the maxillary sinuses were mostly located in the first premolar (49%) and second molar (84%) regions, respectively. Maxillary sinus septa were indentified in 47% of the maxillary antra. Almost 2/3 (66%) of the patients showed major (> 4 mm) mucosal thickening mostly at the level of the sinus floor. The present sample did not allow revealing any significant difference (P > 0.05) in maxillary sinus dimensions for partially dentate and edentulous subjects.

Conclusions

Cross-sectional imaging can be used in order to obtain more accurate information on the morphology, variation, and the amount of maxillary bone adjacent to the maxillary sinus.

Sinus grafting with a natural fluorohydroxyapatite for immediate load: a study with histologic analysis and histomorphometry

The goal of this retrospective study was to evaluate the survival rates of dental implants placed in sinuses grafted with a 50:50 composite ratio of autogenous bone and a natural flourohydroxyapatite (FHA) combined with platelet-rich plasma (PRP) using an immediate-load protocol. The authors hypothesized that a 50:50 composite ratio of FHA and autogenous bone combined with PRP would permit immediate loading without compromising implant survival rates. Eleven patients with bilateral partial edentulism of the posterior maxilla were enrolled in this retrospective study. Autogenous bone used in the graft procedure was harvested from the tibia of the left lower extremity. Each patient was grafted with a 50:50 composite ratio of autogenous bone and FHA. Membranes were not used to cover the lateral wall osteotomy site. Platelet-rich plasma was added to the graft material to accelerate and enhance bone regeneration. Four to 6 months after the grafting procedure, 37 hydroxyapatite-coated dental implants were surgically placed and immediately loaded between 72 hours and 5 days later with custom titanium abutments and acrylic provisional restorations placed out of functional occlusion. Six months later, definitive ceramometal restorations were cemented on to the custom abutments. Patients were observed over a 52-week period. The overall implant survival rate was 97.3%. Histologic and histomorphometric analysis of core samples revealed formation of new vital bone in different graft specimens ranging from 23% to 34%. In each core bone sample, 100% of the bone sample was determined to be vital. In the grafted maxillary sinus, the natural FHA combined with autogenous bone in a 50:50 composite ratio with PRP is a suitable graft material permitting immediate load without compromising implant survival rates while decreasing the overall healing time.

Volume and distances of the maxillary sinus in craniofacial deformities with midfacial hypoplasia

OBJECTIVE

Craniofacial deformities (CFDs) frequently accompany midfacial hypoplasia. The authors evaluated characteristics of maxillary sinuses that had CFDs with variable degrees of midfacial hypoplasia.

STUDY DESIGN

Cross-sectional survey with chart review.

SETTING

Department of Plastic and Reconstructive Surgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.

SUBJECTS AND METHODS

We investigated 40 patients with CFDs having midfacial hypoplasia. Study group 1 (SG 1) consisted of eight patients with Crouzon syndrome (16 maxillary sinuses). Study group 2 (SG 2) consisted of 10 patients with midfacial hypoplasia after palatoplasty (20 maxillary sinuses). Study group 3 (SG 3) consisted of 22 patients with Pruzansky grade I hemifacial microsomia (22 maxillary sinuses on the affected sides). Data on volume and three-dimensional distances (height, width, and depth) from computed tomography were collected and compared with each corresponding control group. Correlation coefficient between volume and the three distances was also calculated.

RESULTS

The volume, height, width, and depth of the maxillary sinus were significantly decreased in SG 1 (P < 0.01). In SG 2, only the depth was significantly decreased (P < 0.05). In SG 3, there were no significant differences in any parameters. A multiple-regression analysis between the volume and the three distances showed a statistically significant relationship for width in SG 1, width and height in SG 2, and all distances in SG 3.

CONCLUSION

There were differences in the structure of the maxillary sinuses among patients with different CFDs.

Maxillary sinus anatomy: a cadaveric study with clinical implications

This study measured maxillary sinus volume, evaluated the location of the semilunar hiatus in correlation to the nasal floor, and the incidence, location, and height of antral septa and discusses their clinical implications. Maxillary sinus volume was quantified in 65 cadavers (130 sinuses) by water application through the semilunar hiatus and measuring the used amount. The location of the semilunar hiatus was identified as distance from the nasal floor. The septa were counted, evaluated, and the size measured from the antral floor. The medium maxillary sinus volume was 12.5 mL (range, 5-22 mL). The medium location of the semilunar hiatus was 25.6 mm above the nasal floor (range, 18-35 mm). Thirty-five septa were counted in 130 maxillary sinuses. This equals an incidence of 27%. The medium height of the septa was 5.4 mm (2.5-11 mm). The main location of the septa was the region of the first molar (29%), the second molar (23%), and the second premolar (23%). The height, location, and number of septa as well as the height of the semilunar hiatus and volume of the maxillary sinus have to be taken into consideration to correctly plan the procedure and amount of grafting material in maxillary sinus floor elevation operations.

Are culture-expanded autogenous bone cells a clinically reliable option for sinus grafting?

OBJECTIVES

This prospective clinical study was designed to examine the healing process during the first 12 months after sinus grafting (SG) with autogenous culture-expanded bone cells (ABC) and bovine bone mineral (BBM) histomorphometrically and radiologically.

MATERIAL AND METHODS

Twenty-two sinuses of 12 patients (mean age 56.2+/-9.3 years) were grafted. Four weeks before, SG bone biopsies were obtained with a trephine burr and the bone cells were isolated and expanded. Every sinus was grafted with BBM and ABC. After 6 months, a biopsy was taken from each sinus and implants (n=82) were placed. These were uncovered after another 6 months and fitted with dentures. The percent newly formed bone (NB) and the NB-to-BBM contact area were determined on undecalcified histologic sections. The sinus graft volume was evaluated by dental CT after SG (CT 1), after implant placement (CT 2) and after implant uncovery (CT 3).

RESULTS

Postoperative healing was uneventful. The NB was 17.9+/-4.6% and the contact area 26.8+/-13.1%. The graft volume (in mm(3)) was 2218.4+/-660.9 at the time of CT 1, 1694+/-470.4 at the time of CT 2 and 1347.9+/-376.3 at the time of CT 3 (P<.01). Three implants were lost after uncovery. Reimplantation and prosthodontic rehabilitation were successful throughout.

CONCLUSIONS

These results suggest that SG with ABC and BBM in a clinical setting provides a bony implant site which permits implant placement and will tolerate functional loading.

CT-based manual segmentation and evaluation of paranasal sinuses

Manual segmentation of computed tomography (CT) datasets was performed for robot-assisted endoscope movement during functional endoscopic sinus surgery (FESS). Segmented 3D models are needed for the robots' workspace definition. A total of 50 preselected CT datasets were each segmented in 150-200 coronal slices with 24 landmarks being set. Three different colors for segmentation represent diverse risk areas. Extension and volumetric measurements were performed. Three-dimensional reconstruction was generated after segmentation. Manual segmentation took 8-10 h for each CT dataset. The mean volumes were: right maxillary sinus 17.4 cm(3), left side 17.9 cm(3), right frontal sinus 4.2 cm(3), left side 4.0 cm(3), total frontal sinuses 7.9 cm(3), sphenoid sinus right side 5.3 cm(3), left side 5.5 cm(3), total sphenoid sinus volume 11.2 cm(3). Our manually segmented 3D-models present the patient's individual anatomy with a special focus on structures in danger according to the diverse colored risk areas. For safe robot assistance, the high-accuracy models represent an average of the population for anatomical variations, extension and volumetric measurements. They can be used as a database for automatic model-based segmentation. None of the segmentation methods so far described provide risk segmentation. The robot's maximum distance to the segmented border can be adjusted according to the differently colored areas.

Immediate loading of the grafted maxillary sinus using platelet rich plasma and autogenous bone: a preliminary study with histologic and histomorphometric analysis

OBJECTIVE

The goal of this clinical study was to evaluate dental implant survival rates using the concept of a nonfunctional, immediate loading protocol with nonsplinted dental implants in the grafted maxillary sinus during a 52-week period. Random histomorphological and histomorphometric analysis was completed to evaluate the early healing effect of platelet rich plasma (PRP) and 50% autogenous bone combined with 3 different substitute graft materials.

MATERIALS

Four to 8 months after grafting the sinus with PRP sprayed autogenous bone combined with 3 different substitute graft materials in a 50:50 composite ratio, 27 hydroxyapatite- coated dental implants were surgically placed in 41 patients and immediately loaded between 48 hours and 5 days later with custom titanium abutments and acrylic provisional restorations placed out of functional occlusion. Six months later, definitive ceramometal restorations were cemented on to the custom abutments.

RESULTS

During a 52-week observation period, no implants were lost. Between 4 and 8 months of graft healing time, histologic and histomorphometric analysis revealed formation of new vital bone in different graft specimens ranging from 77% to 100%.

CONCLUSION

The preliminary results of this clinical study indicate that immediate nonfunctional loading using PRP and 50% autogenous bone combined with different substitute graft materials is a predictable protocol in the grafted maxillary sinus as early as 4 months of postgrafting. The high implant survival rate is due to the early formation of large percentages of new vital bone as confirmed by using histologic and histomorphometric analysis.

Volumetric evaluation of the paranasal sinuses in normal subjects using computer tomography images: a stereological study

OBJECTIVE

The size and shape of paranasal sinuses are especially relevant when considering endoscopic sinus surgery. For this reason, the size of the paranasal sinuses has been the subject of many studies, none of which has used stereological methods to estimate the volume. In the present stereological study, we estimated the volume of paranasal sinuses of normal males and females.

MATERIAL AND METHODS

We used a combination of the Cavalieri principle and computer tomography scans taken from 39 male and 38 female patients to estimate the volumes of frontal, maxillary, ethmoidal and sphenoidal sinuses.

RESULTS

The mean volumes of frontal, maxillary, ethmoidal and sphenoidal sinuses were estimated bilaterally, producing mean volumes of 11.6+/-0.8, 35.9+/-1.3, 11.8+/-0.4 and 13.6+/-0.7 cm(3), respectively. When the correlations between estimated volumes were analyzed statistically a positive relation was found for the paranasal sinuses. The size of the sinuses tends to decrease with age.

CONCLUSION

The findings of the present study using the stereological methods could provide data for the evaluation of normal and pathological volumes of the paranasal sinuses.

Análise por tomografia computadorizada do enxerto autógeno na cirurgia de "sinus lift"

OBJETIVO: Quantificar a formação óssea nos enxertos com e sem plasma rico em plaquetas, obtido pelos métodos de centrifugação e aférese, comparando os três tipos de enxertos realizados por meio de análise tomográfica. MATERIAIS E MÉTODOS: Este estudo prospectivo, duplo cego, utilizou uma amostra composta de 34 pacientes adultos, de ambos os sexos, com idade média de 48 anos e 8 meses, portadores de pneumatização unilateral ou bilateral dos seios maxilares, que necessitavam de enxertos ósseos, com a finalidade de melhorar as condições locais para a colocação dos implantes dentários. Todos os pacientes realizaram tomografia computadorizada antes da cirurgia. Foram operados 53 seios maxilares, divididos em três grupos: enxerto de plasma rico em plaquetas obtido pelos métodos de aférese, centrifugação e enxerto apenas de osso autógeno. Após seis meses do procedimento cirúrgico foram realizados novos exames de imagem. RESULTADOS: Pela avaliação tomográfica, houve crescimento em altura e em largura nos três grupos quando foram comparados os momentos inicial e final, entretanto, não houve diferença estatística para a altura e para a largura. CONCLUSÃO: Evidências clínicas demonstram a eficácia dos enxertos autógenos, principalmente os associados a fatores indutores de crescimento ósseo, como o plasma rico em plaquetas, recuperando o arcabouço maxilofacial, necessário para a reconstrução protética e funcional por meio de implantes dentários.

Effects of sinus lifting on voice quality. A prospective study and risk assessment

A variety of potential complications associated with sinus lift surgery have been reported in the literature. However, potential alterations of voice quality following sinus elevation have so far not been mentioned or evaluated scientifically. For the majority of patients, slight changes of the voice pattern are of no importance. However, for voice professionals, whose voices have become part of their distinctive profession or trademark, minimal changes may have dramatic consequences. This specific group of patients, such as speakers, actors and singers, depend on the particular quality and timbre of their voice for their livelihood. Consequently, the purpose of this study was to assess the effects of sinus lifting on voice quality in the above patient group. In a collaborative interdisciplinary effort, the Departments of Oral Surgery and Otorhinolaryngology, Section of Phoniatrics and Logopedics, thoroughly evaluated a series of voice parameters of four patients undergoing sinus lifting pre- and postoperatively. The parameters analyzed included pitch, dynamic range, sound pressure level, percent jitter, percent shimmer and noise-to-harmonics ratio with special emphasis on formant analysis. No changes were detected in any of the commonly evaluated parameters. These were rated subjectively by patients and their friends or relatives and objectively with instrumental tools under isolated phoniatric lab conditions. In conclusion, sinus lift surgery appears to be a safe, predictable evidence-based method for regenerating the highly atrophic posterior maxilla, which does not jeopardize the individual characteristic voice pattern of high-profile patients critically dependent on their voices for their livelihood.