Lips and noses in 10-year old patients with repaired complete unilateral clefts of lip, alveolus, and palate. A prospective three-centre study of the Baltic Cleft Network.

This multicenter study aimed at comparing different techniques of lip and nose repair with or without NAM and primary anterior rhinoplasty in pre-adolescent children. Patients with unilateral clefts of lip, alveolus, and palate who had undergone cleft lip and nose repair were evaluated in a prospective three-centre study using standardized monochromatic, cropped photographs. Four cleft surgeons evaluated the aesthetics of the central part of the face when the patients had reached age ten years. Seventy-six sets of photographs out of 87 patients were evaluated. The overall ratings of lips and noses did not differ much between centres. However, noses of centres 1 (mean 0.74; SD 0.57) and 2 (mean 0.76; SD 0.60) had been rated better than centre 3 (mean 1.32; SD 0.78; p = 0.0078), especially "Deformation of upper part of nostril rim or poor position of alar cartilage". Centre 3 had produced better looking scars (mean 0.33; SD 0.48); p = 0.0036. Within the limitations of the study it seems that NAM and primary anterior rhinoplasty including postoperative nasal stents should be performed whenever possible in order to achieve a favorable shape of the nose and to reduce the need for secondary corrective surgery.

Bone formation in mono cortical mandibular critical size defects after augmentation with two synthetic nanostructured and one xenogenous hydroxyapatite bone substitute - in vivo animal study.

OBJECTIVES: Healing characteristics as well as level of tissue integration and degradation of two different nanostructured hydroxyapatite bone substitute materials (BSM) in comparison with a deproteinized hydroxyapatite bovine BSM were evaluated in an in vivo animal experiment. MATERIAL AND METHODS: In the posterior mandible of 18 minipigs, bilateral mono cortical critical size bone defects were created. Randomized augmentation procedures with NanoBone(®) (NHA1), Ostim(®) (NHA2) or Bio-Oss(®) (DBBM) were conducted (each material n = 12). Samples were analyzed after five (each material n = 6) and 8 months (each material n = 6). Defect healing, formation of soft tissue and bone as well as the amount of remaining respective BSM were quantified both macro- and microscopically. RESULTS: For NHA2, the residual bone defect after 5 weeks was significantly less compared to NHA1 or DBBM. There was no difference in residual BSM between NHA1 and DBBM, but the amount in NHA2 was significantly lower. NHA2 also showed the least amount of soft tissue and the highest amount of new bone after 5 weeks. Eight months after implantation, no significant differences in the amount of residual bone defects, in soft tissue or in bone formation were detected between the groups. Again, NHA2 showed significant less residual material than NHA1 and DBBM. DISCUSSION: We observed non-significant differences in the biological hard tissue response of NHA1 and DBBM. The water-soluble NHA2 initially induced an increased amount of new bone but was highly compressed which may have a negative effect in less stable augmentations of the jaw.

Centre-based statistics of cleft lip with/without alveolus and palate as well as cleft palate only patients in Aden, Yemen.

OBJECTIVE: The purpose of the study was to report the types and patterns of cleft lip with/without cleft alveolus and palate as well as cleft palate only as seen in Aden, Yemen. DESIGN AND SETTING: Retrospective, centre-based study conducted at the Cleft Lip and Palate Centre, Aden University, Yemen. MATERIAL AND METHODS: Statistical evaluation of the data from all cleft patients who were registered at or referred to this centre during the years 2005-2011. RESULTS: A total of 1110 cleft patients were seen during the period studied (2005-2011). Amongst these there were 183 (16.48%) with a cleft lip and 144 (12.98) with a cleft of lip and alveolus, 228 (20.54%) had a cleft palate, and 555 (50%) had a combination of cleft lip, alveolus, and palate. The clefts were found more often in males than in females (56.5% boys versus 43.5% girls). This difference was statistically significant (p ≤ 0.001). Statistically significant sex differences were also noted when evaluating the various cleft types. Isolated cleft palates were found most often in females. Among the cleft palate cases there were 102 (9.2%) with a cleft soft palate only. The ages of the patients were between one day and 40 years. Two hundred and one children (18%) had a positive family history of clefts. Among the risk factors considered in this study, consanguineous marriages among cousins were found most frequently (in 48% of the cases). In contrast to this, only 10% of the mothers had reported to have been taking medication directly prior to or during the first trimester of their pregnancy. On average the mothers were neither very young nor very old. CONCLUSION: The prevalence rate of orofacial cleft types among this Yemeni sample was similar to prevalence rates previously reported in white Caucasians. The present study did neither find many cases with medication before, nor during, pregnancy; there were few young or very old mothers; and the incidence of positive family histories was similar to those found in other studies on clefts. However, consanguineous marriages were encountered quite often.

The isolated mandibular ramus - a hitherto rarely described anomaly of the mandible. Pathogenesis and treatment.

INTRODUCTION: A very famous paper by Sam Pruzansky, published in 1969, was entitled "Not all dwarfed mandibles are alike". This is the topic of this paper: to describe the shape and discuss the possible pathogenesis of an extremely rare congenital dysplasia found in a unilaterally hypoplastic mandible, namely the isolated mandibular ramus. MATERIAL AND METHODS: A unique malformation of the lower jaw was found in more than 75 patients with developmental abnormalities of the mandible diagnosed and treated by the two authors in two different university hospitals over the last 40 years. We performed the following teratological experiments with laboratory rodents in order to try to understand the pathogenesis of this special dysplasia (and others): at first the normal development of the lower jaw was studied in rat and mouse foetuses. Then a variety of teratogenic drugs were applied to pregnant females and then the foetuses of these pregnancies were studied following Caesarian section. RESULTS: One rat foetus was identified which presented the identical dysplasia that had been noted in the patient described here. The dam pregnant with this foetus had been given 25 mg/kg bodyweight of 6-mercaptopurine on day 12 of pregnancy. The explanation found for the pathogenesis of this anomaly was deducted from the scientific literature regarding normal development of the mandibular condyle. CONCLUSION: The nucleus of the so-called secondary cartilage that will produce the ascending ramus (plus condyle and coronoid) is a separate growth centre which fuses a short time later with the dental bone which becomes the mandible proper by this fusion.

Two-stage palatoplasty, is it still a valuable treatment protocol for patients with a cleft of lip, alveolus, and palate?

INTRODUCTION: Speech development is of utmost importance and requires early closure of a palatal cleft. On the other hand, it is well known that all types and timings of surgical repair of facial clefts are detrimental to maxillary growth. Nevertheless, these days one is more and more confronted with a world-wide tendency in favour of the one-in-all operation to close clefts of the lip, alveolus, and palate. Therefore, a three-centre study was performed for testing - once more - the value of two-stage palatoplasty as a means to reduce the detrimental effects of surgery on palatal growth and at the same time to also enable early speech development. MATERIAL AND METHODS: Plaster casts from 85 patients have been re-evaluated. All of them had a complete unilateral cleft of lip, alveolus, and palate. They had been treated according to the old therapy protocols followed in either one of the three different cleft centres many years ago, namely in Hamburg, (Western) Germany, Iowa City, IO, USA, and Rostock, (in those days still Eastern) Germany. The impressions had been taken already in 1987 from patients being either 8 years (36 pts.) or 16 years of age (49 pts.). Three different treatment protocols had been followed for these patients in those centres in those days: The main difference was that in centres A and B the palates were closed in two stages whilst in centre C palatoplasty was performed in just one operation. RESULTS: The most interesting results regarding the palatal growth were that: 1. In centre C (one-stage palatoplasty) the patients had more constricted palates. 2. In centre A (two-stage palatoplasty) the patients had least often an anterior cross-bite. DISCUSSION AND CONCLUSION: It appears that it was possible to show once more that closing the palate in one stage at age 1 year or less is interfering most with maxillary growth. This study leads us to conclude that two-stage palatoplasty is still a valuable treatment protocol for patients with a complete unilateral cleft of lip, alveolus, and palate, especially as apparently good guidance of speech development can lead to satisfactory speech for cleft patients in whom the hard palate was closed at a later age.

How to do clinical research in cranio-maxillo-facial surgery.

INTRODUCTION: Not many randomised controlled trials are published in surgical journals, especially those on maxillo-facial surgery. There appears to be some uncertainty on how to perform such studies. Accordingly this paper offers some information on how to plan, pursue and publish a well conducted case-control study, or the more powerful randomised control trial. RESULT: The main section describes how to define a relevant clinical question, and a research protocol, the way to implement the study, and it helps to find funding for such research. It also explains the various study designs, gives a very short introduction to statistics and on how to appraise the results achieved, and it advises on writing and submitting the resultant manuscript. CONCLUSION: This paper offers a guide for young colleagues who wish to perform a study, write a paper and achieve publication in one of our leading speciality journals.

A preliminary study in osteoinduction by a nano-crystalline hydroxyapatite in the mini pig.

To test the probable osteoinductive properties of NanoBone, a new highly non-sintered porous nano-crystalline hydroxylapatite bone substitute embedded into a silica gel matrix, granules were implanted subcutaneously and intramuscularly into the back region of 18 mini pigs. After periods of 5 and 10 weeks as well as 4 and 8 months, implantation sites were investigated using histological and histomorphometric procedures. Signs of early osteogenesis could already be detected after 5 weeks. The later periods were characterized by increasing membranous osteogenesis in and around the granules leading to the formation of bone-like structures showing periosteal and tendon-like structures with bone marrow and focal chondrogenesis. Bone formation was better in the subcutaneous than in the intramuscular implantation sites. This ectopic osteogenesis is discussed with regard to the nanoporosity and microporosity of the material, physico-chemical interactions at its surface, the differentiation of osteoblasts, the role of angiogenesis and the probable involvement of growth factors. The results of this preliminary study indicate that this biomaterial has osteoinductive potential and induces the formation of bone structures, mainly in subcutaneous adipose tissue in the pig.

Ankylosis of the temporomandibular joint.

INTRODUCTION: True ankylosis of the temporo-mandibular joint must be differentiated from other reasons why a patient is unable to open his mouth properly. It can be treated by various methods. It is the purpose of this paper to (a) Present various cases with different disorders that had lead to a restricted mouth opening and (b) Report upon the long-term post-operative results achieved by having applied various treatment options for true ankylosis of the temporomandibular joint (TMJ). MATERIAL AND METHODS: In 40 patients a true ankylosis was treated surgically by applying one of the two protocols: Either by interposing silastic sheetings or by implanting a TMJ prosthesis made of metal and consisting of 2 parts, a condylar head and a temporal fossa. Twenty patients could be followed up after 113 months on average - 13 patients of these have been treated by interposition of silastic and 7 have received endoprostheses. In 7 other patients, different reasons were found inhibiting freely opening the mouth. Congenital bony ankylosis of upper and lower alveolar processes, congenital or acquired bony fusion of the coronoid process with the zygomatic arch and/or temporal bone, acquired ankylosis between mandible and lateral pterygoid plate, ossifying myositis, or fibrosis of masticatory muscles following tumour irradiation. Not all of these could be operated upon and not all of these could be followed up. However, all patients operated upon followed a strict postoperative physiotherapeutic regimen. RESULTS: Long-term follow-up maximum interincisal distances (MiDs) were callipered: 34mm (mean; min. 22, max. 52) following silastic sheeting; 18mm (mean; min. 10, max. 23) following endoprosthesis implantation. In the one of the two patients who could be followed up after ankylosis of the coronoid with the temporal bone, the MiD measured 49mm 1 year postoperatively. In that one of the two patients who could be operated because of a unilateral bony fusion between the mandible and the pterygoid plate, MiD was only 26mm 8 years postoperatively. And in the one of the two males who could be followed up 8 years after operation of myositis ossificans, MiD measured 50mm. CONCLUSION: There are several possible reasons why a patient cannot open his mouth widely. Six of these have been touched upon, 4 of these have been operated upon. For true ankylosis silastic (sheeting or blocks) is felt to be the best material for interposition following osteotomy. Postoperative physiotherapy is a conditio sine qua non - it is the second most important part for every type of treatment for ankylosis.

Epidemiological studies on the frequency of clefts in Europe and world-wide.

BACKGROUND: Most textbooks present data on the various frequencies of clefts in different human "races". This was studied in more detail. MATERIAL AND METHODS: In a major literature study the frequencies of clefting reported in more than 100 publications were studied and the following data was collected: Incidences of clefts in Mongolians, Caucasians and Negroids; relative frequencies of clefts of the primary (and secondary) palate versus that of clefts of the secondary palate (only); data on cleft location (right, left, bilateral) and on genders affected. RESULTS: There was most confusing data on incidences in the different "races" whilst all other data was rather consistent: complete clefts (i.e. primary plus secondary palate affected) were most common with left sided ones being reported most often; males were more prone to have a cleft of the primary palate than females and females were more often affected by clefts of the secondary palate than males. DISCUSSION: The types of data bases having been evaluated varied from report to report indicating that today's data pools are of different qualities. Regional or national registries are necessary to collect reliable data with strict definitions applied in all countries.

Presurgical orthopaedic treatment of newborns with clefts--functional treatment with long-term effects.

AIM: Presentation of an orthopaedic/orthodontic treatment protocol within the framework of complex rehabilitation of patients with clefts of lip, alveolus and palate. Presurgical orthopaedic treatment aims at reduction of cleft size by guiding growth and functional rehabilitation. Long-term results of maxillary development and occlusion at young adult age are reported. PATIENTS AND METHODS: 43 newborns with unilateral (19) or bilateral (24) clefts of lip, alveolus and palate were examined until their deciduous dentition was complete. In 29 patients a late follow-up was performed at age 17.3 years (mean). Maxillary dental casts were evaluated prior to and following presurgical orthopaedic treatment at the time the deciduous dentition was complete and at young adult age (2 to 5 years after termination of orthodontic treatment). Parameters were width of the alveolar and palatal cleft as well as width and length of the dental arch. In the adults occlusion was studied and the occlusal outcome was related to the therapeutical input. RESULTS: Presurgical orthopaedic treatment reduced the cleft width by taking advantage of normal growth. At the age of 3 to 4 years the development of the upper dental arch was in line with that of non-cleft children. CONCLUSION: Maxillary growth may be guided in almost physiological terms even in patients with a cleft of lip, alveolus and palate. Prerequisite is functional rehabilitation by means of orthopaedic treatment at age 1 to 12 months in terms of functional orthodontic therapy and a surgical protocol saving tissues with growth potential.

Macroscopical, histological, and morphometric studies of porous bone-replacement materials in minipigs 8 months after implantation.

OBJECTIVE: The aim of this investigation was to test the induction of bone formation and biodegradation of different biomaterials based on calcium phosphate (CaP). Up to now, hydroxyapatite and beta-tricalcium phosphate ceramics have routinely been sintered at temperatures of 1300 degrees C. The new CaP biomaterials tested are fabricated by a sol-gel process at only 700 degrees C. STUDY DESIGN: Critical-size defects (>5 cm(3)) in the mandible of 15 adult Goettingen minipigs were filled with 1 of the 2 new types of CaP biomaterials, or with 1 of 2 well-known old-type ceramics, or with a gelatin sponge (in the control group). Macroscopical, histological, and morphometric examination of the former defect areas were made 8 months postoperatively. RESULTS: Eight months after implantation of the new CaP biomaterials, complete bone formation was observed in the defect area, and at the same time, the foreign material was resorbed almost completely. After implantation of the classical types of ceramics, only incomplete bone formation and a lesser resorption rate of the foreign bodies were noted. The difference in the bone formation rate was significant: more than 93% for the new CaP biomaterials versus less than 58% for the classical types of ceramics (P < 0.01). CONCLUSION: The biological behavior of the new CaP biomaterials was better than that of the old-type sintered ceramic bone-grafting materials. These new CaP matrices are suitable for filling bone defects and are of interest for dentists, including implantologists, craniomaxillofacial and orthopedic surgeons, as well as traumatologists.

Ossification of the frontal sinus in juvenile minipigs following water jet application.

BACKGROUND: Obliteration of the frontal sinus is a generally accepted management for patients with severe craniofacial trauma in whom the sinus cannot be repaired or adequately drained. Effective obliteration requires complete removal of mucosa, sufficient filling of the sinus cavity as well as effective occlusion of the nasofrontal duct. The use of various filling materials for sinus obliteration has been described and include autologous fat, bone, muscle and lyophilized cartilage. MATERIAL AND METHODS: In order to appreciate the advantages of the water-jet scalpel an animal study in 10 juvenile (4 months old) and 10 adult (18 months) minipigs was performed. In 5 juvenile and 5 adult animals the frontal sinus mucosa was removed using the water jet, while in the others bone curettes were used. No occlusion of the frontonasal duct was carried out and no filling material was implanted. All animals were followed-up for 40 days. After sacrifice, radiological, histological and computerized histomorphometrical examinations were carried out. RESULTS: Removal of the mucosa from the sinus was simplified when using the water jet. Previous studies have shown that the selected tissue structures were less traumatized when compared with conventional surgical techniques. In young animals (only) and exclusively following the use of a water-jet scalpel osseous occlusion of the frontal sinus was found at follow-up. Histomorphometric findings revealed a significant increase of bone formation in the frontal sinus area of these animals. CONCLUSION: Based on these experimental results in a small series of juvenile minipigs the water-jet technique is a faster and less traumatic technique (less blood loss) for osteoplastic surgery of the frontal sinus. Further long-term studies are needed to evaluate the possibilities for applying this technique in post-traumatic craniofacial surgery in man.

Does avascular necrosis of the jaws in cancer patients only occur following treatment with bisphosphonates?

INTRODUCTION: In the last decade, bisphosphonates were regularly used to treat osteoporosis and bone pain from diseases such as metastatic breast cancer, multiple myeloma and Paget's disease. Currently, the influence of bisphosphonates in development of avascular osteonecrosis of the jaws has been recognized by various authors. In many cancer patients chemotherapy and medications like steroids have also to be applied. Agreement exists that these drugs can initiate vascular endothelial cell damage and accelerate disturbances in the microcirculation of the jaws possibly resulting in thrombosis of nutrient end arteries. The role of bisphosphonates in cancer patients with previously treated jaws has yet to be elucidated. PATIENTS: Four case reports of 'cancer' patients are described in whom osteonecrosis of the jaws was found. In two patients, the nitrogen-containing bisphosphonate zoledronic acid was prescribed for additional therapy of malignancy for a period of 45 up to 70 months. In another case, supportive treatment of breast cancer was offered using ibandronate. The fourth patient suffered avascular necrosis of the mandible without ever having taken bisphosphonates. In any case, revisional, as well as extended surgery has to be performed for osteonecrosis because neither conservative debridement nor antibiotic therapy have shown long term success, with or without bisphosphonates. No withdrawal of bisphosphonates was performed in view of the information on the direct correlation of total dosage and duration of drug intake to systemic incorporation and the long time for drug release. CONCLUSION: According to our observations, withdrawal of bisphosphonates is not recommended when necrosis of the jaws has occurred.

Initial findings on teratological and developmental relationships and differences between neural tube defects and facial clefting. First experimental results.

Unless genetically caused, the occurrence of neural tube defects and clefts of the lip, alveolus and palate are not associated. These malformations do, however, share some common causes, one of which is folic acid deficiency. Nevertheless, it is not known why a neural tube defect resulting from folic acid deficiency does not occur in combination with facial clefts. Based on animal experiments and a review of the literature, it is assumed that other factors--such as vitamin B6 deficiency--though clinically not diagnosed, can more often cause malformations.

Pneumosinus dilatans frontalis: two case reports.

INTRODUCTION: Pneumosinus dilatans was described first in 1898 by Meyes. Up to now only 60 cases have been published worldwide dealing mainly with young men between 20 and 30 years of age. The aetiology remains unknown. Whilst frontal sinuses are affected most often other sinuses can also be involved. The expansion of the pneumosinus is not only an aesthetic problem but may also have functional consequences. There may be a bulging of the roof of the orbit with consequent global displacement, ocular alterations and ptosis. Other features are headache and anosmia. PATIENTS: Two male patients with a pneumosinus dilatans of the frontal sinus are presented. They were 22 and 25 years old. The main complaints were aesthetic disfigurement. Treatment consisted of craniofacial repair of the malformation. RESULTS: While one patient was lost to follow-up, the other still is happy and has a stable aesthetic long-term result.

Repair of bone defects by applying biomatrices with and without autologous osteoblasts.

QUESTION: Is it possible to stimulate osteoconduction and osteogenesis to improve bone formation in critical-size defects in order to avoid bone grafting? MATERIAL AND METHODS: Full thickness, critical-sized defects were created in the anterior mandible of 16 adult mini-pigs. The defects were filled with a new bioactive matrix (60% hydroxyapatite and 40% beta-tricalciumphosphate), produced by an innovative low temperature sol-gel-process (120 degrees C). The biomatrix was tested alone and in combination with cultured autologous osteoblasts. In a control group, periosteum was the only bone producing source. Five weeks postoperatively, the animals were sacrificed and the defects analysed macroscopically, histologically and radiographically. RESULTS: The highest rate of new bone formation was in the biomatrix group without osteoblasts (73% of the former defect). The biomatrix was degraded at the same speed as new bone was laid down. In the control group, bone formation of only 59% was observed. Additional transplantation of autologous osteoblasts in combination with the biomatrix did not result in more bone production than in the control group(!). CONCLUSION: This new bioactive calciumphosphate matrix seems to be a promising bone replacement material.

Reconstruction of the frontal calvarian continuity in a child using a freeze-preserved autogenous bone graft.

Today, extended craniofacial defects in childhood can be treated by using modern techniques of bone banking and osteosynthesis, of particular importance when the restoration needs to consider calvarial growth. This is a report of an 8-year-old boy whose right frontal bone was removed during primary multidisciplinary trauma care. The bone was stored at a tissue bank using sterilization and freeze-dried preservation. Nine months later the graft was replaced and fixed with resorbable miniplates. Postoperatively no complications were observed and the (auto)graft has taken well. There was symmetrical craniofacial growth as well as a good aesthetic result three years after reconstruction.

Position of the hyoid bone in cleft lip, alveolus, and palate: variation of normal anatomy or sign accompanying the malformation?

OBJECTIVE: To compare the hyoid bone position in patients with clefts of lip, alveolus, and palate with orthodontic patients with no cleft. DESIGN: Retrospective cephalometric long-term study. PATIENTS: Lateral cephalograms of 23 patients with a complete unilateral cleft were compared with those of 24 orthodontic patients with no cleft with an Angle class 1 occlusion. Twenty-five of the patients were girls, and 22 were boys. The age of the patients with cleft at the beginning of the study was 8.1 +/- 0.7 years and at the end 14.8 +/- 0.6 years. The patients without cleft were 8.4 +/- 0.8 years old at the beginning and 14.4 +/- 0.6 years at the end of the study. MAIN OUTCOME MEASURES: Cephalometric analysis was used to determine the skull growth pattern as well as the positions of the head and hyoid bone twice in all 47 persons. RESULTS: With increasing age of the patients, the skull growth pattern changed from vertical to horizontal growth, but no significant differences were found between patients with and without cleft. Head position did not differ significantly between patients with and without cleft. However, hyoid bone position differed significantly. The hyoid in patients with cleft was located more caudally and more anteriorly than in patients without cleft. CONCLUSION: The hyoid bone in a subset of north German adolescents with complete unilateral cleft lip and palate was found to be caudal and anterior, compared with a control group.

Experimental and comparative study of the blood supply to the mandibular cortex in Göttingen minipigs and in man.

INTRODUCTION: Since the blood supply to the mandibular cortex is an important factor for bone growth and bone repair, experimental studies on the blood supply in animal models (such as Göttingen minipigs) applicable to man are necessary. Their value depends on the requirement that the patterns of blood supply in the two species are similar. MATERIAL AND METHODS: Twelve Göttingen minipig mandibles (24 halves) and four human mandibles (eight halves) were investigated for the blood supply to the mandibular cortex. RESULTS: Only minor differences were found in blood supply to the mandibular cortex between the two species. Common to both was: in the cranial part of the mandible (including the condyle), the endosteal blood supply prevailed, whereas the periosteal blood supply predominated in the caudal part of the mandible (the body). Both patterns of blood supply were in balance in the centre section, i.e. angle and ascending ramus of the mandible. CONCLUSION: The present study confirms that results obtained from Göttingen minipigs, used as an experimental animal model, are applicable to man: three different types of blood supply are evident in the mandibular cortex in both species.

Blood supply of the mandibular cortex: an experimental study in Göttingen minipigs with special reference to the condyle.

INTRODUCTION: Blood supply of the mandible is an important factor that influences bone growth and bone repair. MATERIAL AND METHODS: An experimental study was carried out in 24 mandibles of 12 Göttingen minipigs to study the blood supply of the mandibular cortex. RESULTS: Endosteal blood supply prevails in the cranial part of the mandible including the condyle, whilst periosteal blood supply predominates in the caudal part of the mandible, the body. The two forms of blood supply are in balance in the ascending ramus and the angle of the mandible. CONCLUSION: The mandibular cortex can be divided into three parts, each having different sources of blood supply. The results of this study may be of significance for man and could help to understand some pathological disorders of the mandible.