Louis J. Baume

Is the condylar growth center responsive to orthodontic therapy? An experimental study in Macaca mulatta.

Abstract A review of the recent literature indicates that, contrary to Wolffs law and Rouxs principle, epiphyseal cartilage plates remain highly unresponsive to mechanical stimuli. A controlled experiment in three rhesus monkeys, aged 44 to 50 months, was designed to assess condylar response to orthopedic stimulation. Roentgenographic, vital-staining, and histologic analyses of the temporomandibular articulations after treatment periods of two and one-half and four and one-half months, respectively, yielded the following results: 1. 1. The condylar cartilage with its endochondral growth apparatus responded most actively to functional therapy. Upon treatment, the condylar head assumed a prolonged, bilobed shape as part of a growth response that tended to compensate for the induced mandibular displacement. 2. 2. Transformations of the joint structures of the temporal bone remained at a microscopic level. Comparison with experimental results so far published (Table II) suggests that this was due to the advanced age of the animals and the shortness of the experiment. The unique properties of condylar cartilage among the endochondral growth apparatus were evaluated both from the biologic aspect and from the standpoint of its impact on orthodontic therapy.

Ontogenesis of the Human Temporomandibular Joint: 2. Development of the Temporal Components

The embryologically unique origin of the temporomandibular joint from two separately (in time and space) developing blastemas was further studied in relation to temporal structures. Both coronal and sagittal sections of 11 human fetuses from the 24 mm to 72 mm crown-rump (C-R) stage showed that the glenoid blastema developed in close relationship with the primordial quadrate-meckelian joint to form the bony temporal joint components, including the capsular elements of the upper joint story. The disk developed independently of the tendon of the external pterygoid muscle as a derivative of both the condylar and the glenoid blastemas.

Diagnosis of diseases of the pulp

Abstract On the basis of a combined clinical and histologic study of 270 affected pulps, the possible classification of the pulpal states, the pathogenesis of pulpal inflammation, and the possibility of differentiating the various pathologic conditions by clinical criteria were evaluated. In compliance with the suggestion made by the World Health Organization in the International Classification of Diseases, a clinical classification of the pulpal states for therapeutic purposes was suggested (Table III). The study of the dynamics of pulpal pathosis led to a pathogenic classification that is in harmony with the thinking of general pathology (Table IV), eliminating ill-defined notions such as “hyperemia,” “serous pulpitis,” etc. Evidence was presented (Table V) that it was completely hazardous to differentiate the various pathologic states of the pulp by clinical criteria. Histopathologic classification, therefore, was referred to the laboratory for scientific investigations. The symptomatic classification was considered to be best suited to serve the needs of daily practice.

Growth and transformation of the Temporomandibular joint in an orthopedically treated case of Pierre Robin's syndrome

Abstract An infant affected with Pierre Robins syndrome of micrognathia was treated orthopedically at the age of 2 months. After five months of therapy, normal jaw relations were established. The child died of other causes at the age of 9 months. The histologic analysis of the temporomandibular joint revealed the following: 1. 1. The temporal structures of the joint gave evidence of an orthopedically induced transformation in the sense of a forward displacement of the fossa by coordinated processes of bone apposition and bone resorption. 2. 2. Absence of traumatic injuries of the capsular structures was noted. 3. 3. The condylar head showed growth activity in the vertical and horizontal directions exceeding the normal rate. 4. 4. These histologic peculiarities are identical with those described by Breitner, Haupl, and Hoffer in similarly treated experimental monkeys. These observations lead to the following conclusions: 1. 1. The scope of orthodontic treatment is not necessarily limited to transformations of the periodontal structures of the jaws. Even parts of the temporal bone may be influenced by orthodontic appliance therapy. 2. 2. X-ray analysis does not reveal the entire picture of orthodontically induced growth changes. Animal experimentation remains an important aid for the bioassay of orthodontic therapy. 3. 3. Haupls functional jaw orthopedics takes best advantage of the morphogenetic property of functional stimuli (Roux 21 ), although any other appliance system may produce the same effect.

Uniform methods for the epidemiologic assessment of malocclusion. Results obtained with the World Health Organization standard methods (1962 and 1971) in South Pacific populations.

Abstract 1. 1. Data by age, sex, and ethnic group are reported on the dental eruption pattern and the frequency distribution of severe malocclusions and their types, respectively, among 21,325 inhabitants of the Society Islands, Western Samoa, and the Australes Archipelago, using the WHO standard methods. 2. 2. In Polynesians the eruption pattern was characterized by an early emergence of the accedaneous permanent teeth and a “sexdimorphous” difference in the premolar and canine group of succedaneous permanent teeth. There was intraracial variance in the timing of tooth eruption, apparently due to socioeconomic conditions. Tahitians, subject to rampant decay, developed their full set of permanent teeth earlier (if ever) than the relatively caries-free Samoans and Australasians. Evidence was presented to show that the change in dietary habits of Tahitians has brought about a reduction in the dietary fluoride uptake from natural foods at the expense of highly cariogenic, imported carbohydrates. 3. 3. Severe malocclusion occurred in only 5 to 7 per cent of the three population samples examined and hence constituted no public health problem. Caries in the Tahitians and periodontal diseases in all Polynesian groups constituted the real danger for harmonious occlusion. 4. 4. Crowding was the relatively most frequent malocclusion in all three samples. In spite of rampant decay, Tahitians showed the same rate as the other caries-free groups, probably because of a still favorable jaw growth factor. 5. 5. The distribution of severe mesiocclusion and distocclusion revealed a certain racial trend. Mesiocclusion was consistently more frequent in pure Polynesians than among the mixed ones. It also showed a consistently higher prevalence than distocclusion. Severe distocclusion affected only three in 1,000 of relatively purebred Polynesians, while in the mixed groups it affected one to seven in 100. The conjecture based on epidemiologic and paleopathologic data that racial intermixture may constitute a genetic factor in the development of distocclusion has been discussed. 6. 6. In view of data presented, retention of simple malocclusion indices in the WHO Basic Survey Methods appears to be justified. Much needed information on the genetic and racial background of certain malocclusions may be obtained from simple prevalence studies of isolated population groups.

Clinical evaluation of four amalgam alloys: A five-year report

In this study 96 teeth of 12 patients were restored with either the conventional alloy Premix, the blended non-gamma 2 amalgam Dispersalloy, or one of the spherical alloys Sybraloy and Tytin. To ascertain an objective comparison of the clinical performance of these alloys, two different alloys were used in each of at least two dental arch quadrants in the same patient and consequently were placed in the same oral environment. Clinical performance of the restorations was evaluated by macrophotography and scanning electron microphotography of replicas made after placement and 2, 3, and 5 years thereafter. Standard criteria were used for the evaluation of anatomic form, surface condition, and marginal adaptation of the fillings. In addition, the filling-enamel interface was assessed from the microphotographs. The three high-copper alloys performed better clinically than the conventional alloy, and the spherical alloys had the best qualifications. In addition to visual examination and photographic evaluation of restorations, the micrometric assessment of replica photographs from the scanning electron microscope may render clinical trials of amalgam alloys measurable and less subjective.

Response of Condylar Growth Cartilage to Induced Stresses

The endochondral growth apparatus of the mandibular condyles, in contrast to epiphyseal plates of long bones, reacts positively to mechanical stimulation. Roentgenographic and histologic analyses of the joint structures of two experimental rhesus monkeys, when compared with untreated controls, showed obvious morphologic and structural transformations of the condylar heads as the result of the instituted treatment. Corollary differences were found in the ontogenetic and histogenetic pattern, as well as in the hormonal control, of these condylar growth centers.

Radicular pulpotomy of category III pulps. Part III. Histologic evaluation

Abstract Twenty-two sound or symptom-free restored teeth (indicated for extraction) of patients 18 to 60 years of age were subjected to radicular pulpotomy and immediate root canal filling. 2 Eight contralateral teeth served as untreated controls. The histologic evaluation led to these results. The untreated control teeth showed regressive changes in the apical third of the radicular pulps consisting of the disappearance of the odontoblasts, von Korff fibers, and the subodontoblastic vascular network starting at the apex and gradually ascending. The regression increased with age. All the treated teeth showed a vital remaining pulp free of inflammation and necrosis. One month postoperatively capping was effected by dentinal chips encapsulated by a fibrotic tissue. Osteodentin matrix formation had begun around advanced dentin chips and at discrete sites of the dentinal walls, while at other areas modeling resorption took place. The frequency and extent of dentinoclasia seemed to depend on the height of the pulpotomy, but they never constituted a clinical problem since dentinoclasia would repair with osteodentin. The remaining tissue had the characteristics of loose connective tissue. Three months postoperatively, the remaining pulp size had been reduced by osteodentin deposition along the dentinal walls and around the dentinal chips thus forming a more or less complete seal. Calcific obliteration depended on the presence of a dentinal plug and its proximity (3 to 5 mm.) to the apex. This was associated with a progressive fibrosis of the remaining pulp tissue in the absence of inflammatory changes. In the light of the favorable biologic results obtained, it may be justified to introduce radicular pulpotomy into daily practice under the conditions that its specific indications for category III pulps are respected and its exacting techniques applied.

Embryogenesis of the Human Temporomandibular Joint

The structures of this articulation were found to originate from two different blastemata situated at some distance from each other and operating at different rates and opposing directions. A condylar blastema evolving dorsally contributes to the formation of the condylar cartilage, the disc, the aponeurosis of the external pterygoid muscle, and the capsular elements of the lower joint level, while a temporal blastema develops the articular structures of the upper level in a forward direction. At the end of the fourth fetal month all joint elements including a glenoid fossa and articular eminence are present in their primitive form.

Microradiographic assessment of neodentinal bridging following direct pulp capping in human teeth

Neodentinal bridges formed in 14 human premolars following direct pulp capping with a calcium hydroxide paste (Pulpdent) were microradiographically assessed. Densitometric measurements were made in the longitudinal sections of the bridges, revealing an increase in the mean mineral content per volume after progressively longer postoperative periods ranging from 2 to 15 wk. Transverse measurements made through each of two 15-wk bridges confirmed the presence of three layers: the superior amorphous layer yielded the lowest mineral content of 32.3 and 34.8% by volume; the medial (atubular) fibrodentine layer exhibited the highest scores of 48.1 and 50.1%, greater than those of the lateral dentine walls (43 to 48%); and the inferior juxtapulpal layer of tubular orthodentine contained 41.0 and 42.2% mineral per volume. With the new photoelectronic ASBA equipment the presence of centers of high mineral density within the medial fibrodentinal layer was confirmed.