[Alveolar ridge augmentation with cortical osteotomies for dental implantation]. / Les ostéotomies corticales d'augmentation alvéolaire en chirurgie implantaire.

Cortical osteotomies allow alveolar ridge augmentation so as to place dental implants of adequate size, most often in one step. This technique is reliable and allows long-lasting prosthetic restoration, without need for a graft-harvesting site. We report an expansion technique, which combines various cortical alveolar osteotomies. It allows guiding bone fractures away from the implant site during the expansion procedure. The possibility of implant placement is enlarged because exposure risks for implants are limited. The technique also preserves cortical bone structure and resistance, while allowing a larger bone augmentation movement. The diameter, axis, and crestal emergence position are optimized, thus improving the biomechanical resistance of implant restoration. A better implant position and restoration of bone anatomy and volume, supporting the gingival alveolar mucosa, improve the esthetic and prosthetic result. This technique can be used if the ridge is very narrow with limited bone elasticity. We present the various osteotomies and basic surgical steps for transversal and even vertical alveolar ridge augmentation, as well as possible modifications and clinical results.

[Mandibular hemangiopericytoma, a malignant vascular tumor]. / L'hémangiopéricytome mandibulaire, une tumeur vasculaire maligne.

INTRODUCTION: Hemangiopericytoma is a rare tumor, arising from pericytes, which are perivascular cells belonging to the capillar walls. OBSERVATION: A 41 year old man consulted for a mandibular tumor. The clinical and radiographic diagnosis was difficult. The biopsy performed in the operative room led to an embolization decided in emergency, and proved the definitive diagnosis. Despite the embolization, bleeding during surgical excision of the tumor compelled us to perform an external carotid artery ligature. The mandibular reconstruction was performed using a trapezium osteo-muscular flap. DISCUSSION: As reported in the literature, the radiographic diagnosis of hemangiopericytoma is difficult, the malignant potential is variable and the recommended treatment is surgical excision.

Vascularization of the palate in maxillary osteotomies: anatomical study.

Le Fort 1 maxillary osteotomy carries a risk of injury to the descending palatine arteries which vascularize the bulk of the mucosa of the bony palate. Some authors believe that injury to these arteries in the greater palatine canal is intrinsic to the procedure without any consequence for the trophicity of the mucosa or bony palate. In order to assess the risk of injury to the descending palatine arteries during such surgery, and to demonstrate the supplementary vascularization which would avoid ischemia of the palate, we carried out a study of the vascularization of the palate on 11 fresh cadavers. We used intra-arterial injection of colored latex and dissection of the vessels running to the palate. The study was done without osteotomy in the first subject, after a Le Fort 1 osteotomy in the five following subjects and after a Le Fort 1 osteotomy and ligation of the two descending palatine arteries in the last five subjects. Our results show that injury of the descending palatine arteries is not intrinsic to the procedure in spite of mobilization of the palatine plateau. When the descending palatine arteries are ligated there is diminution in coloration of the mucosa of the bony palate but there is substitution by the arteries vascularizing the soft palate, essentially the ascending palatine artery and the pharyngeal branch arising from the ascending pharyngeal artery. However, this substitute vascularization has individual variations.

Surgical anatomy of the nose in the elderly: value of conservative rhinoplasty by transoral route.

Functional or aesthetic rhinoplasty is being done later and later in life. It is essential to know the characteristics of morphological ageing of the nose in order to modify surgical techniques. An anatomical study was carried out on 40 fresh cadavers more than 70 years old. All the subjects studied were measured to define the external morphology of the nose. Amongst these 40 subjects, 20 were dissected plane by plane, 10 were operated on by a new conservative rhinoplasty technique utilizing a strictly transoral route and 10 were operated on by a classical rhinoplasty technique. The anatomy of the nose in the elderly subject is characterized by thinner skin, subcutaneous fat infiltrating in the muscles in 50% of cases and the small muscles of the tip of the nose undergoing complete involution. The technique of rhinoplasty described here shows the value of better respecting lesions at the tip of the nose which is particularly fragile in the aged subject. It may be extended to post-traumatic rhinoplasties or to the nose which has already been operated on.

[The growth of the maxilla in humans. What place for the premaxilla?]. / La croissance du maxillaire chez l'homme. Quelle place pour un prémaxillaire?

INTRODUCTION: The growth of the maxilla in man is still debated. Many authors described an anterior part of the maxillary bone, called premaxilla distinct from the maxilla proper. This description referred to the existence in animals of an incisive or premaxillary bone which does not exist in man. Is this distinction pertinent in the human facial growth? MATERIAL AND METHODS: To settle this question, we performed a histologic study in eight embryos and fetuses aged from 40 days to 10 weeks post conceptional (PC) and an anatomic dissection of 3 palates of fetuses aged from 22 to 30 weeks PC. RESULTS: We found only one maxillary point of ossification, and the growth of the anterior part of the maxilla cannot be separated from the global growth of the maxilla. DISCUSSION: The independence of the anterior part of the maxilla in man is very limited during the growth and cannot justify the term of premaxilla.

Relations of the accessory nerve with the internal jugular vein: surgical implications in cervical lymph node clearances.

The position of the lateral branch of the accessory nerve in relation to the internal jugular vein is given variously by different authors. In surgery of the neck, and especially in conservative cervical lymph node clearances, the lateral branch of the accessory nerve is protected when it is situated lateral to the vein. However, when the nerve is medial to the vein there is a risk of damage to the internal jugular vein. A prospective preoperative study of 123 cervical lymph node clearances, as well as a dissection study of 5 fresh subjects, was carried out to determine the position of the lateral branch of the accessory nerve in relation to the internal jugular vein. The surgical study showed that the lateral branch of the nerve was anterior and lateral to the vein in 122 of the 123 clearances, while the cadaveric study found the nerve always anterior and lateral to the vein. Thus the risk of injuring the internal jugular vein during cervical lymph node clearances is very small. The differences observed by authors may be explained by collapse of the internal jugular vein observed during cadaveric dissections.

[Screening of cancerous and precancerous lesions of the oral mucosa in an at-risk population]. / Dépistage des lésions cancéreuses et pré-cancéreuses de la muqueuse buccale dans une population à risque.

Early diagnosis of oral carcinomas allows a limitation of functional consequences of surgical treatment. A prospective study was designed in 270 alcoholic patients. We practiced a clinical examination of the oral cavity by a stomatologist followed by a Toluidin blue test. The clinical examination permitted to detect 1 carcinoma and 23 leukoplakias. The Toluidin blue test revealed one more carcinoma and two leukoplakias more. The early diagnosis of oral carcinomas in alcoholics patients gives them a better survival. The Toluidin blue test could be proposed as an aid to early diagnosis of these carcinomas.

[Whole saliva flowmetry. Evaluation of 3 measurement technics]. / Débimétrie salivaire globale. Evaluation de 3 techniques de mesure.

Several methods traditionally have been used to collect and measure whole mouth saliva. The purpose of the study was to determine resting and stimulated whole saliva secretion rates and to evidence decreased saliva production (xerostomia) in outpatients' clinic. In this prospective study, saliva production was quantified by swab weighing, suction method (before and after chewing) and by oral sugar clearance. The 3 methods were carried out in 30 healthy subjects (16 females and 14 males) and 7 subjects with dry mouth (2 females and 5 males). Our results indicate that whole saliva formation can be reliably quantitated by standardized procedures of weighing sterile sponge and suction methods on healthy subjects. But the suction technique was found to be inferior in the group with xerostomia (impossibility of quantitative measurement in 5 patients out of 7). The 3 methods did significantly differ when mean flow rates in the group with xerostomia and in the healthy group were compared (p < 0.01). To conclude, in a physician's office, direct weighing of the swabs can be done easily and more reliable when using a balance that is accurate to 0.1 gm. Oral sugar clearance can be used to screen for xerostomia.

[Transmission of infection in oral medicine. Evaluation of the risk of transmission in the office surgery]. / Transmission des infections en stomatologie. Evaluation du risque de transmission au cabinet de consultation.

The present study was designed to estimate the risk of transmission of infectious diseases by dental equipment in stomatology. The protocol was carried out on 30 patients. The three following samples were collected from each patient: (a) oral flora before any treatment, (b) aerosol produced by the hand-piece before internal decontamination, (c) aerosol produced by the hand-piece after internal decontamination. The results of this study indicate there was a risk of transmission of infectious diseases in 3 cases (10%) with dental equipment, even if there were no consequences for healthy individuals. We have to improve the security in stomatology, with internal and external decontamination after each patient.