Abstract This study focuses on the development of a bone collecting device for intra-oral bone harvesting and on the introduction of a new bone graft donor site, zygomatic bone. A bone collector was constructed and tested in vitro. This bone collector is suitable and efficient in dental implant related bone grafting surgery. It was also found to be more efficient and with a larger capacity in bone harvesting when compared to the two commercially available bone collectors. A zygomatic bone harvesting technique is introduced in this study. The safety and morbidity of the method was assessed in a cadaver and a prospective clinical study. In the cadaver study, 40 procedures were performed. The complications during the cadaver harvesting included 15 perforations into the maxillary sinus and 7 perforations into the infratemporal fossa. The only intra-operative complication in 32 clinical operations was perforation of the maxillary sinus in 33% of the zygomatic sites. None of these patients experienced any post-operative problems related to the perforation. Patients needed pain medication for a mean time of four days and they did not demonstrate any paresthesias or altered sensations in the donor area. The yield of the bone graft from zygomatic bone was quantified in cadaver and clinical studies. In the cadaver study, the average yield of the graft was 0.59 ml. In the clinical study the average graft volume was 0.90 ml. The required reconstructions were accomplished in all clinical cases. In the prospective clinical study, the bone grafts from the zygomatic bone were used simultaneously with one-stage dental implants placement. Bone grafting was employed at 72 of the 82 implant sites. Two of the bone grafted implants failed, yielding a survival rate of 97.2% for bone grafted implants and 97.6% for the whole study group. Grafted sites healed remarkably well, and no obvious signs of graft resorption were noted during the 26.9 months follow-up period. The bone collector developed in this study is an effective instrument in intra-oral bone harvesting. The zygomatic bone can be regarded as a safe bone harvesting donor site and the yield of bone graft from this area is sufficient for moderate defects in resorbed alveolar ridges.

O aumento da procura pela reabilitação de rebordos desdentados com cirurgias reconstrutivas e implantes osseointegráveis, faz com que se torne necessário um estudo mais detalhado das características anatômicas dos ossos maxilares e suas possíveis variações. Neste contexto, a fixação zigomática é uma alternativa aos enxertos ósseos para a reabilitação de rebordos maxilares atróficos, onde altura e largura da crista óssea insuficientes impedem a instalação de implantes convencionais. As variações da anatomia do osso zigomático indicam a necessidade de um planejamento tridimensional. O exame por tomografia computadorizada de feixe-cônico (TCFC) se mostra adequado para exame das estruturas ósseas maxilofaciais e ainda apresenta vantagens como baixo custo e menor dose de radiação quando comparada à tomografia computadorizada helicoidal. Este estudo, composto de duas amostras independentes, se propôs a avaliar aspectos relacionados à anatomia do osso zigomático (OZ) e, mais especificamente, o forame zigomático-facial (FZF), em pacientes e em crânios macerados. Em um primeiro momento, foram avaliadas, retrospectivamente, imagens de TCFC de 40 pacientes (80 ossos zigomáticos), obtidas pelo aparelho i-CAT Classic®. Foram observados a presença e número do FZF, quando presente; avaliada a espessura média do OZ e delimitada uma região no osso zigomático a partir de pontos antropométricos Jugale (Ju) e Zigomaxilare (Zm), para dimensionar o local de inserção de implantes zigomáticos, em valores de área e volume. A incidência de um único forame foi observada em 40% dos ossos zigomáticos (n=32), dois forames em 20% (n=16), e três em 3,75% dos OZs (n=3). Em 36,25% dos ossos zigomáticos (n=29), o forame estava ausente. A espessura média do OZ encontrada foi de 10,3mm, variando de 5,45mm a 16,8mm. A área e volume médios para instalação de implantes zigomáticos foi de 147,93mm2 e 1102,9 mm3, respectivamente. Em um segundo momento, foram estudados 151 crânios macerados, totalizando 302 ossos zigomáticos, quanto à presença e número do FZF, quando presente, e a incidência encontrada foi de um forame em 44% dos ossos zigomáticos (n=133), dois forames em 28% (n=86), e três em 8% dos OZ (n=24). Em 19% dos ossos zigomáticos (n=57), o forame estava ausente e em 2 casos apenas haviam quatro forames (1%). Destes 151 crânios, 20 foram selecionados aleatoriamente para mensuração do diâmetro desses FZF, e posteriormente os mesmos foram submetidos à TCFC para que se avaliasse a acurácia deste exame em mostrar esta estrutura anatômica (FZF). A média de diâmetro encontrada foi de 0,57mm (±0,27mm). Todos os forames, mesmo os de menor calibre puderam ser observados nos cortes tomográficos. Os resultados levam a concluir que o exame tridimensional do osso zigomático é de extrema importância quando se pretende intervir nesta região, dada a sua variabilidade anatômica, e que a tomografia computadorizada de feixe cônico se mostrou adequada para esta finalidade. / The increased demand for rehabilitation of edentulous ridges with reconstructive surgery and dental implants, does it become necessary a more detailed study of the anatomical features of the jaws and their possible variations. In this context, the zygomatic implants are an alternative to bone grafting in the rehabilitation of atrophic maxillary ridges, where insufficient height and width of the bony crest prevent the installation of conventional implants. The variation in the anatomy of the zygomatic bone indicates the need for a three-dimensional planning system. Examination by cone-beam computed tomography scan is more appropriate for a thorough examination of the maxilofacial structures and has advantages as low cost and less radiation dose compared with convencional computed tomography. This study, composed of two independent samples, aimed to evaluate aspects related to the anatomy of the zygomatic bone and more specifically, the zygomatic-facial foramen in patients and in macerated skulls. At first, were evaluated, retrospectively, the CBCT images of 40 patients (80 zygomatic bones), obtained by the apparatus i-CAT Classic®. Were observed the presence and number of ZFF, when present, evaluated the average thickness of ZB and mapped an area on the zygomatic bone from anthropometric points Jugale and Zigomaxilare to scale the approximate area of insertion of zygomatic implants, in area values and volume. The incidence of a single foramen was found in 40% of zygomatic bone (n = 32), two foramen in 20% (n = 16) and three at 3.75% ZB (n = 3). In 36.25% of the zygomatic bone (n = 29), the foramen was absent. The average thickness of ZB was found to be 10.3 mm, ranging from 5.45 mm to 16.8 mm. The average area and volume for installation of zygomatic implants was 147.93 mm2 mm3 and 1102.9, respectively. In a second step, were studied 151 macerated skulls, totaling 302 zygomatic bones regarding to the presence and number of ZFF were evaluated, when present, and the incidence found was a foramen in 44% of the zygomatic bone (n = 133), two foramina in 28 % (n = 86) and three in 8% of ZB (n = 24). In 19% of zygomatic bone (n = 57) the foramen was absent and in only 2 cases had four foramen (1%). Of these 151 skulls, 20 were randomly selected for measuring the diameter of ZFF, and later they were submitted to CBCT in order to assess the accuracy of this exame to show this anatomical structure (ZFF). The average diameter was found to be 0.57 mm (± 0.27 mm). All foramen, even with smaller diameters were observed in tomography slices. The results support a conclusion that the tridimensional exam of the zygomatic bone is extremely important when it intends to intervene in this region, in view of the anatomical variability, and that the CBCT is more suitable for this purpose.

O aumento da procura pela reabilitação de rebordos desdentados com cirurgias reconstrutivas e implantes osseointegráveis, faz com que se torne necessário um estudo mais detalhado das características anatômicas dos ossos maxilares e suas possíveis variações. Neste contexto, a fixação zigomática é uma alternativa aos enxertos ósseos para a reabilitação de rebordos maxilares atróficos, onde altura e largura da crista óssea insuficientes impedem a instalação de implantes convencionais. As variações da anatomia do osso zigomático indicam a necessidade de um planejamento tridimensional. O exame por tomografia computadorizada de feixe-cônico (TCFC) se mostra adequado para exame das estruturas ósseas maxilofaciais e ainda apresenta vantagens como baixo custo e menor dose de radiação quando comparada à tomografia computadorizada helicoidal. Este estudo, composto de duas amostras independentes, se propôs a avaliar aspectos relacionados à anatomia do osso zigomático (OZ) e, mais especificamente, o forame zigomático-facial (FZF), em pacientes e em crânios macerados. Em um primeiro momento, foram avaliadas, retrospectivamente, imagens de TCFC de 40 pacientes (80 ossos zigomáticos), obtidas pelo aparelho i-CAT Classic®. Foram observados a presença e número do FZF, quando presente; avaliada a espessura média do OZ e delimitada uma região no osso zigomático a partir de pontos antropométricos Jugale (Ju) e Zigomaxilare (Zm), para dimensionar o local de inserção de implantes zigomáticos, em valores de área e volume. A incidência de um único forame foi observada em 40% dos ossos zigomáticos (n=32), dois forames em 20% (n=16), e três em 3,75% dos OZs (n=3). Em 36,25% dos ossos zigomáticos (n=29), o forame estava ausente. A espessura média do OZ encontrada foi de 10,3mm, variando de 5,45mm a 16,8mm. A área e volume médios para instalação de implantes zigomáticos foi de 147,93mm2 e 1102,9 mm3, respectivamente. Em um segundo momento, foram estudados 151 crânios macerados, totalizando 302 ossos zigomáticos, quanto à presença e número do FZF, quando presente, e a incidência encontrada foi de um forame em 44% dos ossos zigomáticos (n=133), dois forames em 28% (n=86), e três em 8% dos OZ (n=24). Em 19% dos ossos zigomáticos (n=57), o forame estava ausente e em 2 casos apenas haviam quatro forames (1%). Destes 151 crânios, 20 foram selecionados aleatoriamente para mensuração do diâmetro desses FZF, e posteriormente os mesmos foram submetidos à TCFC para que se avaliasse a acurácia deste exame em mostrar esta estrutura anatômica (FZF). A média de diâmetro encontrada foi de 0,57mm (±0,27mm). Todos os forames, mesmo os de menor calibre puderam ser observados nos cortes tomográficos. Os resultados levam a concluir que o exame tridimensional do osso zigomático é de extrema importância quando se pretende intervir nesta região, dada a sua variabilidade anatômica, e que a tomografia computadorizada de feixe cônico se mostrou adequada para esta finalidade. / The increased demand for rehabilitation of edentulous ridges with reconstructive surgery and dental implants, does it become necessary a more detailed study of the anatomical features of the jaws and their possible variations. In this context, the zygomatic implants are an alternative to bone grafting in the rehabilitation of atrophic maxillary ridges, where insufficient height and width of the bony crest prevent the installation of conventional implants. The variation in the anatomy of the zygomatic bone indicates the need for a three-dimensional planning system. Examination by cone-beam computed tomography scan is more appropriate for a thorough examination of the maxilofacial structures and has advantages as low cost and less radiation dose compared with convencional computed tomography. This study, composed of two independent samples, aimed to evaluate aspects related to the anatomy of the zygomatic bone and more specifically, the zygomatic-facial foramen in patients and in macerated skulls. At first, were evaluated, retrospectively, the CBCT images of 40 patients (80 zygomatic bones), obtained by the apparatus i-CAT Classic®. Were observed the presence and number of ZFF, when present, evaluated the average thickness of ZB and mapped an area on the zygomatic bone from anthropometric points Jugale and Zigomaxilare to scale the approximate area of insertion of zygomatic implants, in area values and volume. The incidence of a single foramen was found in 40% of zygomatic bone (n = 32), two foramen in 20% (n = 16) and three at 3.75% ZB (n = 3). In 36.25% of the zygomatic bone (n = 29), the foramen was absent. The average thickness of ZB was found to be 10.3 mm, ranging from 5.45 mm to 16.8 mm. The average area and volume for installation of zygomatic implants was 147.93 mm2 mm3 and 1102.9, respectively. In a second step, were studied 151 macerated skulls, totaling 302 zygomatic bones regarding to the presence and number of ZFF were evaluated, when present, and the incidence found was a foramen in 44% of the zygomatic bone (n = 133), two foramina in 28 % (n = 86) and three in 8% of ZB (n = 24). In 19% of zygomatic bone (n = 57) the foramen was absent and in only 2 cases had four foramen (1%). Of these 151 skulls, 20 were randomly selected for measuring the diameter of ZFF, and later they were submitted to CBCT in order to assess the accuracy of this exame to show this anatomical structure (ZFF). The average diameter was found to be 0.57 mm (± 0.27 mm). All foramen, even with smaller diameters were observed in tomography slices. The results support a conclusion that the tridimensional exam of the zygomatic bone is extremely important when it intends to intervene in this region, in view of the anatomical variability, and that the CBCT is more suitable for this purpose.

Les sutures crâniennes ont été régulièrement étudiées au fil des siècles puisque déjà Vésale établissait une relation entre l’âge et la synostose suturale. Leur imprécision a quelque peu confiné l’observation de ces sutures dans un certain oubli, justifié en partie. Il est clair que leur fiabilité quant à l’estimation de l’âge au décès reste discutable et ce, pour diverses raisons. Leur observation est difficile et dès lors sujette à subjectivité dans l’appréciation de leurs stades de fusion. De plus, leur apparence sur le crâne sec peut être altérée par divers artéfacts de conservation (cire, vernis…). Outre l’observation des classiques sutures ectocrâniennes de voûte et l’utilisation des méthodes habituelles en la matière (méthode de Acsádi et Nemeskéri, méthode de Masset), nous avons orienté notre étude vers des sutures peu voire pas exploitées, à savoir les sutures palatines, les sutures fronto-naso-maxillaires et les sutures de l’os zygomatique. Ces trois groupes suturaux ont la particularité d’évoluer de manière très lente vers la fusion, à tel point que peu d’individus en présentent une oblitération complète. Face au vieillissement de la population et de par notre expérience médico-légale et anthropologique d’étude de pièces osseuses de personnes âgées, nous avons estimé qu’il était utile de se pencher sur des collections particulières de sujets d’âge avancé, afin d’apprécier l’évolution morphologique de ces sutures faciales. Si certaines personnes fort âgées gardent malgré tout des caractéristiques suturales peu évoluées, il existe dans l’ensemble, une progression suturale quasiment constante en fonction de l’âge. Nous avons tenté de la cerner, en attribuant à ces sutures, des degrés bien définis de cette progressive fusion et par là, l’aboutissement à un coefficient moyen d’oblitération suturale, se traduisant aisément en pourcentage d’oblitération ou pouvant être introduit dans des équations de régression. Tout en connaissant les limites de cette approche, nous pouvons estimer qu’elle peut rendre des services lors de l’étude de restes humains squelettisés, notamment s’ils appartiennent à des personnes fort âgées, dès lors qu’à ces stades de vieillissement, peu de méthodes restent encore applicables. D’autre part, l’approche en pourcentage d’oblitération suturale rend également des services lorsque les crânes étudiés sont fragmentés. C’est la situation que nous rencontrons actuellement lors de l’étude d’une très importante collection anthropologique à l’Institut royal des Sciences naturelles de Belgique. Cette observation suturale pourra également – à l’avenir – trouver un terrain d’approche fort utile par l’étude des sutures en CT-Scan ou en micro-CT. Enfin, grâce à ces techniques modernes d’imagerie médicale, les sutures trouvent un regain d’intérêt dans une application toute particulière, qui est celle de l’identification comparative, puisqu’il apparaît que le « dessin sutural » s’avère tout à fait propre à chaque individu.

Les sutures crâniennes ont été régulièrement étudiées au fil des siècles puisque déjà Vésale établissait une relation entre l’âge et la synostose suturale.<p><p>Leur imprécision a quelque peu confiné l’observation de ces sutures dans un certain oubli, justifié en partie.<p><p>Il est clair que leur fiabilité quant à l’estimation de l’âge au décès reste discutable et ce, pour diverses raisons.<p><p>Leur observation est difficile et dès lors sujette à subjectivité dans l’appréciation de leurs stades de fusion.<p><p>De plus, leur apparence sur le crâne sec peut être altérée par divers artéfacts de conservation (cire, vernis…).<p><p>Outre l’observation des classiques sutures ectocrâniennes de voûte et l’utilisation des méthodes habituelles en la matière (méthode de Acsádi et Nemeskéri, méthode de Masset), nous avons orienté notre étude vers des sutures peu voire pas exploitées, à savoir les sutures palatines, les sutures fronto-naso-maxillaires et les sutures de l’os zygomatique.<p><p>Ces trois groupes suturaux ont la particularité d’évoluer de manière très lente vers la fusion, à tel point que peu d’individus en présentent une oblitération complète.<p><p>Face au vieillissement de la population et de par notre expérience médico-légale et anthropologique d’étude de pièces osseuses de personnes âgées, nous avons estimé qu’il était utile de se pencher sur des collections particulières de sujets d’âge avancé, afin d’apprécier l’évolution morphologique de ces sutures faciales.<p><p>Si certaines personnes fort âgées gardent malgré tout des caractéristiques suturales peu évoluées, il existe dans l’ensemble, une progression suturale quasiment constante en fonction de l’âge.<p><p>Nous avons tenté de la cerner, en attribuant à ces sutures, des degrés bien définis de cette progressive fusion et par là, l’aboutissement à un coefficient moyen d’oblitération suturale, se traduisant aisément en pourcentage d’oblitération ou pouvant être introduit dans des équations de régression.<p><p>Tout en connaissant les limites de cette approche, nous pouvons estimer qu’elle peut rendre des services lors de l’étude de restes humains squelettisés, notamment s’ils appartiennent à des personnes fort âgées, dès lors qu’à ces stades de vieillissement, peu de méthodes restent encore applicables. D’autre part, l’approche en pourcentage d’oblitération suturale rend également des services lorsque les crânes étudiés sont fragmentés. C’est la situation que nous rencontrons actuellement lors de l’étude d’une très importante collection anthropologique à l’Institut royal des Sciences naturelles de Belgique.<p><p>Cette observation suturale pourra également – à l’avenir – trouver un terrain d’approche fort utile par l’étude des sutures en CT-Scan ou en micro-CT.<p><p>Enfin, grâce à ces techniques modernes d’imagerie médicale, les sutures trouvent un regain d’intérêt dans une application toute particulière, qui est celle de l’identification comparative, puisqu’il apparaît que le « dessin sutural » s’avère tout à fait propre à chaque individu.<p><p>/<p><p>Cranial sutures were regularly studied during centuries since Vésale already established a relationship between age at death and sutural fusion. <p><p>Their inaccuracy somewhat confined the observation of these joints in a certain lapse of memory, partly justified. <p><p>Various reasons clearly indicate that their reliability for age at death estimation remains debatable. <p><p>Their observation is difficult and consequently prone to subjectivity in the appreciation of their stages of fusion. <p><p>Moreover, their appearance on dry cranium can be modified by various artefacts from preserving methods (wax, varnished…). <p><p>In addition to the traditional observation of ectocranial sutures (with the usual methods such as Acsádi and Nemeskéri method and Masset method), we have directed our study towards not much exploited sutures, namely the palatine sutures, the fronto-naso-zygomatic sutures and the sutures of the zygomatic bone. <p><p>These three sutural groups are characteristic by evolving very slowly to fusion, and than, only few individuals present a complete obliteration of the latter. <p><p>Because of general population ageing and our medicolegal and anthropological experience of skeletal remains in elderly, we estimated the usefulness in studying particular collections of old people, in order to appreciate the morphological evolution of these facial joints. <p><p>Despite some very old people who present little evolved sutural characteristics, we consider as a whole, an almost constant sutural progression according to age. <p><p>We tried to define degrees of this progressive fusion and by the way, the result with a sutural obliteration average coefficient, can be easily translate as a percentage obliteration or able to be introduced into regression equations. <p><p>The limits of this approach are well known but we estimate that it is possible to help the examination of human skeletal remains in elderly, although at these stages of ageing, some methods remain still applicable. In addition, the approach expressed as a percentage of sutural obliteration is also very helpful when craniums are fragmented. This situation is currently observed on the anthropological collections at the Royal Belgian Institute of Natural Sciences. <p><p>Furthemore in the future, the sutural observation will find an interesting and useful approach by the study of the joints in CT-Scan or micro-CT. <p><p>At least, thanks to these modern techniques of medical imagery, the sutures find a renewed interest in a very particular application, such as comparative identification. It appears that the "sutural drawing" proves completely specific to each individual. <p><p> / Doctorat en sciences médicales / info:eu-repo/semantics/nonPublished