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52 totally or partially embedded teeth were studied in ground sections by soft microradiography to assess the quality of the enamel and the dentine. In 79 % the dentine was more or less globularly mineralized. In 50 % the dentine-enamel junction (D.E.J.) was more scalloped than normally and in three cases the border-forming globules were vacuolated. All kinds of hypoplasia were found, gross, minor, and tube. The enamel-cementum junction was irregular in 63 %, hypoplastic in 60 %, hypomineralized in 42 %, and provided with loose enamel globules in 27 %. Cementum or bonelike tissue covered the enamel lingually in two front teeth and occlusally in a third lower molar. The fissures could be extremely narrow and penetrate the enamel till near the dentine border. The distance between the fundus of the fissure and the D.E.J, was measured to 0.15-0.5 mm, is one case only 0.06 mm. In their basal parts the fissures could be invaginated or ampullar. T-hypoplasia could be found in the walls or the fundus of the fissu...

One hundred and fifty patients with oroantral communications were examined radiographically and clinically in a prospective study performed in the 4-year period 1968–1972. Radiographically demonstrable pathologic changes of the maxillary sinus mucosal lining were observed in 96 % of cases examined 1–3 days after the closure of oroantral communications. At 3 months postoperatively or later, 85 % of the sinograms were found to be without evidence of radiographic mucosal hyperplasias. Radiographic examination prior to sinus exposure demonstrated pathologic conditions in 36 % of the patients examined. Observations done simultaneously on the ipsilateral side at the different control periods demonstrated a comparatively constant distribution among the different types of radiographic alterations. Bone defects of the maxillary sinus wall in the injured area were found in 7.4 % of the cases examined in standard intraoral radiographs at follow-ups after 3 months or more. The surgical techniques used in this study are discussed in terms of the incidences of failure (3.3 %), gingival remodeling and vestibular sulcus height.

Preoperative rinsing with cetylpyridinium chloride was found to have no effect on the incidence of bacteremia associated with the surgical removal of impacted third molars. A bacteremia was detected in 76 per cent of the patients, with the predominant organisms isolated being anaerobic.

A double blind study was carried out to investigate the prophylactic effect of an alveolar cone containing propylic ester of phydroxy-benzoic acid (PEHB) on the development of alveolitis sicca dolorosa (ASD) in relation to sex and pericoronitis. Three cones, each, containing 3 mg PEHB and 52 mg tablet mass or three placebo cones containing tablet mass only, were inserted in the socket after removal of impacted mandibular third molars. The material consisted of 144 consecutive patients, 76 females and 68 males. A significantly smaller number of ASD was found in the PEHB group in males (P = 0.01). No effect of PEHB could be demonstrated in the female group. No difference was found between PEHB and placebo in patients who had experienced preoperative symptoms. In the male group of patients without preoperative symptoms, significantly fewer cases of ASD developed after treatment with PEHB (P = 0.01). Such an effect was not found in the female group. No side effects were recorded in any of the cases. The results indicate that PEHB, under certain circumstances, may have such an antifibrinolytic effect in vivo that it may hinder a breakdown of the coagulum.

In 58 embedded teeth and 126 follicles it was found that the enamel-forming epithelium could be heavily disturbed especially in narrow fissures and at the cemento-enamel junction by premature reduction preventing the enamel from being fully mineralized. The congestion of capillaries in the connective tissue of the follicle caused hemorrhage which imbibed the epithelium and the enamel stroma. In the follicles two types of hyaline bodies could be discerned. One type consisted of hyalinized islands of odontogenic epithelium. They could calcify and constituted a fluent transition to odontogenic tumors, e.g. odontoma and dentinoma. They were PAS positive and elastin negative. The other type (the Rushton type) consisted of white thrombi in congested capillaries in inflamed areas. They were PAS negative and elastin positive. The described mechanism might explain the caries susceptibility in molars and premolars with narrow fissural pits and grooves. The same is valid for the cervical areas when the enamel epithe...

— The purpose of this investigation was to study colonization and sequencing of oral microorganisms in human tooth fissures. Five human subjects carried a total of 45 crowns of extracted, fully-impacted third molars which were held in place by means of an intraoral appliance. Each specimen was exposed to the oral environment for 1, 2, 3, 5, 7, 9, 12, 15 or 21 d, and prepared under anaerobic conditions for microbiologic analysis of the fissure content. At day 1 and throughout the time sequence studied, cocci (40–70%), Gram-positive rods (20–40%) and Gram-negative rods (5–9%) constituted the predominant flora. Filaments were scarce and were recovered only from plaque more than 15 d old. Approximately 74% of the recovered organisms were acidogenic. S. mutans was found in the fissures of all subjects, but not in all specimens carried by the subjects. The percentage of S. mutans varied largely within the fissures (0–88.9%). S. sanguis was found in amounts equal to S. mutans in all subjects. Lactobacilli were recovered only in a few fissures and then in small numbers. While veillonella was present in all the fissures examined, neisseria was detected in only two subjects.

The incidence of alveolar osteitis can be reduced significantly by lavage of the oral cavity and the area around the lower third molar with an antiseptic mouthwash before extraction. Evaluation of mandibular third molar extractions provides indications of preventive measures to avoid the occurrence of alveolar osteitis. A group of randomly selected patients was given an oral lavage with a phenolated antiseptic mouthwash before extraction. The use of an oral lavage before extraction resulted in fewer instances of alveolar osteitis than in extractions that were not preceded by lavage.

The use of systemic prophylactic antibiotics in third molar surgery is still a controversial issue. A double-blind study has been conducted with 75 selected patients randomized into two groups. After exclusions, 68 patients requiring removal of 133 bone impacted mandibular third molars remained. Surgery was carried out under general anesthesia and a Standard operative technique used. Postoperative raorbidity was assessed by recording trismus, swelling, pain, and the incidence of infection. In the group given an antibiotic 15.1 % of patients and 7.8 % of sockets became infected; in the control group the incidence was 14.3 % and 8.7 %, respectively. Difficult extractions were more likely to give rise to postoperative infection, but neither the state of eruption nor the occurrence of previous pericoronitis appeared to predispose to dry socket. Trismus and swelling were associated with increased difficulty of extraction, but increased pain did not usually occur unless a socket became infected, Differences of overall morbidity between the groups were slight and not statistically significant. The main conclusion from the study is that the use of prophylactic antibiotics in third molar surgery is unnecessary unless specific systemic factors are present.

The direct bonding technique is offered as a treatment method for maxillary impacted canines. Periapical and panoramic radiographs are essential elements in the detection of malposed maxillary canines. Tooth exposure, trauma, and discomfort can be minimized with the use of the direct bonding technique in treatment of maxillary canine impactions.

The enamel and dentine of 106 erupted and unerupted normal teeth from male and female subjects were analyzed for manganese content by neutron activation analysis. Erupted teeth from male and female patients, ages 8–30, contained an average of 0.60 ± 0.04 and 0.25 ± 0.02 μg manganese/g in enamel and dentine respectively. Unerupted teeth contained as much or, in some cases, more manganese than erupted teeth. A fairly consistent enamel manganese/dentine manganese ratio was found averaging 2.5. The evidence indicates that manganese is found consistently in human teeth and is metabolic or internal in origin. Differences were found in the manganese content of enamel and dentine as a function of patient age and sex.

Collagen metabolism of the operculum overlying the crown of the mandibular third molar was studied in patients with and without pericoronitis. The tissues were classified as (J) overlying unerupted lower 3rd molars, (II) the operculum overlying partially erupted lower 3rd molars, (III) same as (II) except in patients having a positive past history of pericoronitis, and (IV) same as (II) except in patients exhibiting signs and symptoms of active infection. All classes of tissue were found to contain 81–82 % water. The total protein recovered in these tissues increased progressively from class I to class IV due to an effect on the acid-soluble fraction. The total collagen levels, on the other hand, decreased. This decrease was similar for class II and III tissues, while the greatest loss of collagen was demonstrated in class IV tissues. All four classes of tissue contained essentially the same concentration of acid-soluble collagen. The loss of collagen appeared to parallel an increased collagenolytic activity of these tissues in culture. Collagenolytic activity of class II and HI tissues was increased and class IV tissues exhibited the greatest increase. The overall changes in protein and collagen metabolism in these tissues due to partial tooth eruption and subsequent infection appeared similar to those observed by others in extra-oral connective tissues subjected lo injury and inflammation. Changes in collagen metabolism could not be correlated with the reported increased susceptibility to pericoronitis of previously infected tissues. The only change observed in these tissues was a higher proportion of acid-soluble protein.

Of 117 symptom-free, fully edentulous subjects examined radiographically, twenty (17.0 per cent) demonstrated some pathologic condition, usually broken roots. preprosthodontic radiographs of the maxilla and mandible of all edentulous patients in need of complete dentures are considered an essential part of a complete oral examination.

Three cases of calcifying epithelial odontogenic tumor, a rare amyloid-producing tumor, have been reported. One occurred in a 47-year-old woman 31 years after the initial operation for its removal, thus illustrating that the lesion may grow very slowly. The tumors were located in the maxillary molar, mandibular molar, and maxillary anterior regions, respectively, and only two were associated with an unerupted tooth. These three examples illustrate the considerable variation in the microscopic appearance of these neoplasms and support the concept that the tumors pass through various developmental stages. Specifically, the neoplastic epithelium degenerates, forming amyloid globules which coalesce and calcify. In the process, the globules change from being PAS negative to being strongly PAS positive. In one case there was a focus of continuity between the overlying gingival epithelium and the neoplastic tissue.

(1968). Positional Relationships of the Retained Premolar: A Clinical-Radiological Study of an Oral Surgical Case Material. Acta Odontologica Scandinavica: Vol. 26, No. 3, pp. 177-184.

(1968). Local factors in impaction of maxillary canines. Acta Odontologica Scandinavica: Vol. 26, No. 1-2, pp. 145-168.

The supporting tissues of the distal surfaces of mandibular second molars in 33 patients with impacted and semi-impacted third molars were studied preoperatively, immediately after removal of the third molars, and 12 months postoperatively. The same tissues were studied in a group of 11 patients with congenital absence of mandibular third molars. Geometrically reproducible radiographs were obtained. In enlargements of the radiographs the height of the bony septum distal to the second molars was measured. Notes were made of the amount of plaque, the severity of gingival inflammation and the depth of the gingival pockets. Twelve months after operation no change was found in the supporting bony tissue, but significant improvements were noted in the clinical variables studied. No significant difference in the supporting bony tissue was found between age-matched groups of patients with and without impacted or semi-impacted third molars, but the clinical condition of the periodontium was significantly worse in the group with third molars. Prophylactic removal of impacted and semi-impacted mandibular third molars would seem to be indicated.

There may be instances in which this technique is applicable in an adult, assuming the risk of pulpal devitalization. After the tooth is firmly established, root canal therapy can be done. In such cases a well-positioned natural tooth, though deliberately devitalized, is preferable to an artificial replacement. The subject of this symposium is most interesting and the pooling of ideas and techniques should lead to refinements which will make our present concepts primitive within a few years.

Citrate content was determined in the outer surface enamel of unerupted human teeth. The citrate content of the outer surface enamel of erupted teeth was higher than that of unerupted teeth, suggesting that citrate is absorbed from the oral environment after eruption of the teeth. No inverse correlation was found between the citrate and fluoride content of the surface enamel of erupted teeth.

It appears from the literature that the defect of a traumatic injury to deciduous teeth may be dilaceration, hypocalcification, or hypoplasia of the permanent successors. A survey is given of eighteen patients with twenty malformed teeth. In eighteen cases, dilaceration was observed, and in two, hypoplasia of the crown. In thirteen cases, trauma to the deciduous dentition was known with certainty from the case histories. In fourteen, dilacerated teeth in the upper jaw were all unerupted; three of the four dilacerated teeth in the lower jaw had erupted, but their pulps appeared to be nonvital. This nonvitality could not be explained. Early consultation with an orthodontist is necessary in order to make a choice of either ligation and orthodontic treatment or removal and orthodontic closure of the diastema.

– A material of 207 permanent teeth (including 90 cases collected from the literature), traumatized during’development by injuries to primary teeth, has been analyzed in a clinical, radiographic, histologic, microradiographic, and electron microscopic study. It appears from this examination that such developmental disturbances may be classified into distinct clinico-pathologic entities, i.e. — (1) white or yellow-brown discoloration of enamel, (2) white or yellow-brown discoloration of enamel and horizontal enamel hypoplasia, (3) crown dilaceration, (4) odontome-like malformation, (5) root duplication, (6) vestibular root angulation, (7) lateral root angulation or dilaceration, (8) partial or complete arrest of root formation, (9) sequestration of entire tooth germ, and (10) ectopic, premature, or delayed eruption or impaction.

The purpose of the present study was to compare two groups of cases selected at random. One group was treated orthodontically and studied years after treatment, and a similar group that was not treated. Each group consisted of twenty-eight patients of whom fifteen were females and thirteen were males. The average age of the treated group was 19 years 8 months and that of the untreated group was 19 years 10 months. The age limits were 11 years 7 months and 42 years 9 months. To process the data statistically, make comparisons, and determine correlations among variables, the I.B.M. No. 1130-8K computer system was used, 23 so that our conclusions are statistically supported. However, these conclusions are valid for these two studied groups and for other groups with the same characteristics. It was found in the present study that, in general, the differences and correlations of variables were more constant and significant in females than in males. The mesiodistal width of the incisors was, on the average, larger in males, in both the maxilla and the mandible. The mesiodistal width of the incisors was related directly to crowding. With large teeth, there was more crowding, particularly if there was a lack of proportion between the upper and lower teeth. Crowding of the mandibular incisors was greater in the untreated group and more noticeable in males. The overbite was found to be, on the average, less in the untreated group in males as well as in females. However, males presented more overbite than females. The correlations between the overbite and crowding showed that, with more overbite, there was more crowding. The overjet, in general, was very similar in both groups but larger in males, decreasing with age. The correlation between the overjet and crowding indicates that, where there was more overjet, there was less crowding. Third molars had no relation with the observed crowding, since the correlations came out null in the maxillary crowding in general and null in the mandibular crowding of males, who presented the most crowding. The correlations between crowding and age show that, with greater age, there was more crowding. This crowding was more noticeable in the mandibles of males of the treated group. The extrusion of the canines influences the intercanine width reduction, and this exerts a direct influence over the mandibular incisor crowding, since it was observed that, with less intercanine width, there was more crowding.

Impacted teeth, even if deeply located in bone, are a potential source of problems if left in denture-bearing areas. A case is described wherein an impacted lower premolar was exposed to the oral environment because of advanced resorption of the alveolar ridge and became infected. Pathologic fracture of the mandible would probably have occurred if the tooth had not been removed. However, the possibility of fracture also existed at the time the tooth was extracted. Atraumatic removal was achieved with a high-speed air turbine.

Various orthodontic methods of bringing unerupted central incisors to the line of occlusion have been discussed. Those mentioned here included the use of a straight arch wire, an arch wire with double horizontal loops, threaded pins inserted in the incisal edges, and twisted brass wires around the necks of the unerupted teeth.

The mandibular right first molar regions of 43 four-day-old Sprague-Dawley rats were traumatized by needle penetration. Three rats were killed immediately and the remainder, after 36 days. Gross and histologic examination revealed enamel hypoplasia, impacted, ankylosed first molars, and an odontoma. A theoretical basis for the findings is suggested.

Analysis of routine panoramic radiographs showed six types of lesions in the 2,486 patients examined. In a total of 463 different types of lesions there were 645 occurrences of abnormality, the most common lesion being embedded teeth. Oral pathologic conditions that occurred in 17% of the patients gave evidence of poor dental care.

I t has been established from several reports published during the last fortyseven years that it is necessary to make radiographic examinations of edentulous jaws before denture construction. l-l7 A digest of these reports shows that from 16 t.o 37.2 per cent of the edentulous patients had abnormalities and/or pathologic conditions (Table I). Most of these investigations, however, were carried out in the United States of America, where the per capita income and the dentist/population ratio (1:2,000) are among the highest in the world. In other words, most of the previous investigations were made in a country in which dental services are more readily avaiIable and more utilized than is the case in many other countries. The objective of the present report is to describe the occurrence of abnormalities and pathoses in the jaws of edentulous patients who are living in a different environment with newly developing socioeconomic conditions. In the area studied, the dentist/population ratio is 1:20,000 and the use of radiographic procedures in diagnosis is not universal. In addition, this report will compare previously reported information with the data obtained from this investigation.

Calcifying epithelial odontogenic tumor associated with the mandible occurs rarely and is thought to be a distinct entity in the classification of odontogenic tumors since there is only slight histomorphologic similarity to the ameloblastoma.

Summary A technique for the extraction of the deeply impacted mandibular tooth via an extra-oral approach is described.

1. 1. The effects of antihistamine therapy on the postoperative sequelae of oral surgery were studied on a double-blind basis, using extended-action tablets of brompheniramine maleate (an antihistamine) and identical placebos. The patients included 114 who were operated on for impaction and 34 other surgical patients who underwent odontectomy, apicoectomy, and alveoloplasty. 2. 2. Among patients who were operated on for impaction, postoperative edema and trismus were significantly less in those who received the active medication than in similar patients who received the placebo. 3. 3. Among patients operated on for other conditions, those who received the active medication did not develop markedly less edema and trismus than did those who received the placebo. 4. 4. The edema and trismus that developed in patients who received the antihistamine were resolved more rapidly and the patients returned to control levels more rapidly than did patients receiving placebo.

T HE general usefulness of histamine-antagonizing agents in the fleld of allergy is we]l established. ~ Further research, both pharmacologic and clinical, has led to many new and useful findings in other fields of medicine. In the field of oral surgery, alleviation of postoperative sequelae, swelling, pain, and trismus was observed tm patients being t~'eated concomitantly for S(mle allergic condition with antihistamines. This led to the assumption that histamine, released from the traumatized area by the damaged cells, was blocked by the action of the antihistamine drugsY With these observations, a new avenue of treatment was opened to research in the field of antihistamines. This article covers an investigation of the role of the antihistamines in the alleviation o[ postoperative swelling, trismus, pain, and nausea due to th(: removal ot! intpae~,d teeth.

The problem of the unerupted or impacted maxillary cuspid is one with which the dentist must frequently cope. The three generally accepted approaches to the management of this problem are extraction of the tooth, surgical exposure of the crown to allow natural eruption to occur, and surgical exposure of the crown and application of orthodontic traction to bring the tooth into the desired position. Selection of a particular treatment method will depend, of course, on the immediate circumstances surrounding the case at hand.

One hundred eight cases of ameloblastoma definitely associated with follicular cysts and/or impacted tooth follicles were compiled from a review of the literature and a study of unpublished cases. A marked reduction in the prevalence of such cases occurred after the age of 30. The evidence presented supports the hypothesis that the potential for forming an ameloblastoma is lost with the transition of odontogenic epithelium to squamous epithelium in impacted tooth follicles and/or follicular cysts as the patient grows older.