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PubMed2005

Success of mineral trioxide aggregate in pulpotomized primary molars.

UNLABELLED: The aim of the present study was to compare, clinically and radiographically, the mineral trioxide aggregate (MTA) to formocresol (FC) when used as medicaments in pulpotomized vital human primary molars. METHODS: The sample consisted of 120 primary molars, all teeth were treated with the same conventional pulpotomy technique. Sixty molars received FC and 60 received MTA throughout a random selection technique. RESULTS: At the end of 24-month evaluation period, 74 molars (36 FC, 38 MTA) were available for clinical and radiographic evaluation. None of the MTA treated teeth showed any clinical or radiographic pathology, while the FC group showed a success rate of 86.8% radiographically and 98.6% clinically. The difference between the two groups in the radiographic outcomes was statistically significant. It was concluded that MTA treated molars demonstrated significantly greater success. MTA seems to be a suitable replacement for formocresol in pulpotomized primary teeth.

Aluminum Compounds↗
PubMed2004

Morphometric analysis of the furcation anatomy of mandibular molars.

BACKGROUND: Successful treatment of molar furcation defects remains a challenge in clinical practice. Knowledge of anatomic factors facilitates predictable management of furcation involvement lesions. The degree of success in managing furcation involvement is inversely related to the horizontal probing depth. The depth of the horizontal component of attachment loss can vary depending on the external tooth-surface reference points used. However, the anatomical factors affecting horizontal component of attachment loss have not been previously assessed. Therefore, this study determined the bucco-lingual measurements of the cemento-enamel junction and the mesial and distal roots and at the level of root separation. METHODS: One hundred extracted permanent human mandibular first (N = 50) and second (N = 50) molars were studied. Four horizontal bucco-lingual widths were measured with calibrated calipers: 1) furcation entrance/roof (FE); 2) cemento-enamel junction level (CEJ); 3) mesial root width (MRW); and 4) distal root width (DRW). RESULTS: The mean widths at FE, CEJ, MRW, and DRW were, respectively, 5.53 +/- 0.45 mm, 8.71 +/- 0.54 mm, 8.57 +/- 0.54 mm, and 7.97 +/- 0.65 mm in the first molars and 5.61 +/- 0.65 mm, 8.40 +/- 0.65 mm, 7.95 +/- 0.88 mm, and 7.16 +/- 0.84 mm in the second molars. Analysis of variance revealed significant differences between FE and the other variables tested. The results showed that the bucco-lingual width of the furcation roof is considerably shorter than the MRW and DRW. The difference in the mean bucco-lingual dimension between FE and the other measurements occurred in all teeth evaluated and varied between 0.7 and 4.30 mm. CONCLUSIONS: Our findings demonstrate that clinical measurements of horizontal probing depth that use the external surfaces of roots as reference points overestimate the true anatomical component of furcation involvement in mandibular molars. Conversely, positive treatment outcomes in these teeth may be underestimated. This has implications not only for clinical practice but also for clinical research studies evaluating treatment outcomes.

Furcation Defects↗
PubMed1994

Three-dimensional measurement study of the maximum protuberance and cervical line of the upper molars.

The maximum protuberance and the cervical line of 48 upper first molars and 56 second molars were observed using a three-dimensional measuring device. On the basis of the results, the relationship between the maximum protuberance and the cervical line was investigated on the respective contour line and lateral aspect waveform. The contour of the cervical line was positioned at the center of the maximum protuberance in both first and second molars. The distance of the lateral aspect between the measurement points of the maximum protuberance and the cervical line were wider in the mesiodistal direction than in the buccolingual direction. In the second molar, the distance between the maximum protuberance and the cervical line was narrower, and the stricture from the tooth crown to the cervical line on the second molar was decreased. The lateral aspect waveform of the cervical line and maximum protuberance tended to be similar, but the top-to-bottom distance of undulation on the maximum protuberance was longer than that of the cervical line. The buccolingual direction of the lateral aspect waveform showed much more marked fluctuations than that of the mesiodistal direction.

Female↗
PubMed1999

An odontometrical difference in the mandibular molars of two laboratory strains of the musk shrew, Suncus murinus, derived from Bangladesh and Tokunoshima Island of Japan.

We investigated an odontometrical difference in the mandibular molars (M1, M2, and M3) of two laboratory strains of the musk shrew (Suncus murinus) originating in Bangladesh (BAN strain) and Tokunoshima Island of Japan (TKU strain). We used skulls from two strains of shrews that were maintained under identical laboratory conditions. Mesiodistal and buccolingual crown diameters in the trigonid and talonid of the mandibular molars were measured with a measuring microscope, calibrated to 0.001 mm. The crown proportion was expressed by the crown indices calculated from the measurements. Size reduction was analyzed quantitatively according to the reduction index. All crown dimensions were significantly larger in BAN shrews than in TKU shrews (P < 0.01). Sexual differences were noted in the talonid dimensions, while interstrain differences were clearly evident in the trigonid dimensions. The crown indices in M1 showed the least interstrain difference of the three molars. The crown indices showed that TKU shrews had relatively larger buccolingual diameters and talonid diameters than BAN shrews, and the reduction indices showed that TKU shrews had relatively larger M2 and M3 than BAN shrews. To extract the variance components of tooth shape, a principal component analysis was performed after the variables were standardized. After Varimax rotation, each factor was interpreted. The first three factors accounted for 79.9% of all variances. The first component represented the mesiodistal crown proportion of the trigonid-to-talonid crown component. The second and third components represented the relative size of buccolingual diameters in the distal molars for M1. The principal component scores showed that TKU shrews had relatively larger talonids and distal molars than BAN shrews.

Animals↗
PubMed1992

Third molars in Norwegian general dental practice.

A questionnaire containing 37 questions on oral surgery was mailed to a systematic random sample of 500 Norwegian general dental practitioners in October 1989. A 60% return rate was obtained. A selected part of the questionnaire was also presented to all 5th-year dental students in Bergen and Oslo. The total return rate was 43%. From the 17 questions dealt with in this paper the following conclusions were drawn: Norwegian general practitioners' attitudes towards indications for third-molar removal are in general agreement with the current conservative approach. Norwegian 5th-year dental students had more radical attitudes. Norwegian general practitioners indicated the use of adequate technical measures when surgically removing third molars in practice. Every month 4.3 patients presented to general practice with symptoms or findings indicating removal of an impacted or partially erupted third molar. This suggests that in 1 year a situation indicating third-molar removal will occur in 20% of the patients who have third molars.

Analgesics↗
PubMed1996

Influence of the antineoplastic agent cyclophosphamide on dental development in rat molars.

The effect of cyclophosphamide (Cy) on tooth development was studied in molars of 18 young Sprague-Dawley rats. Doses of 30 mg/kg body weight of Cy dissolved in 1 ml 0.9% NaCl were administered to 18 experimental rats and 1 ml 0.9% NaCl to 18 control rats at 10 and 13 days of age. The most obvious changes in the experimental teeth could be seen in the developing pulp of the third molar and developing roots of the first and second molars. Wide cell-free areas appeared in the third molar 2 days after the last injection; later these areas turned into mineralized osteodentin. Similar areas could be observed also in the roots of the first and second molars. These changes were related to the developmental stage of the area.

Animals↗
PubMed1978

A comparative study of gonial angle and growth of the lower third molar in cleft lip and palate. An orthopantomographical study.

In children and young adults with cleft lip and palate, the gonial angle, the angle between the lower second molar and the mandibular plane, the angle between the longitudinal axes of the second and third molars as well as the timing of the development of the third molar were investigated on the right and left side from orthopantomograms. The results were compared with the corresponding results in a noncleft Finnish material. The series consisted of 100 randomly selected subjects aged from 10 to 24 years, 57 males and 43 females. One to three orthopantomograms were available for each subject, totalling 201. The results were examined in a cross-sectional and longitudinal material. The right and left gonial angles were not found to differ in the different cleft groups. Among subjects with cleft lip and palate the gonial angle was found to be larger in the different age groups than the corresponding values in the comparison material. In both materials, the gonial angle was found to decrease between the ages of 10 and 15 years. In males with cleft lip and palate the decrease in this angle, however, continued up to the age of 19. The anterior angle between the longitudinal axis of the lower second molar and the mandibular base line was about 10 degrees larger than in the comparison material, being slightly larger than that in the Angle's Class III occlusion type in the comparison material. When examined by degrees of development the development of the lower third molar was delayed approx. 0.9 years in males and 1.6 years in females compared with the corresponding times in the comparison material.

Adolescent↗
PubMed1992

[Alveolar bone resorption process in molar tooth region in calcium-deficient rats].

The present study was carried out to investigate the alveolar bone resorption in the molar tooth region in the rats fed a low calcium diet. Male Wistar rats (70-85g in body weight) were either fed a low calcium diet (0.05% Ca, 0.35% P) or a control diet (0.5% Ca, 0.35% P) by using a pair feeding technique. The rats were sacrificed at intervals of 3, 6, 9 and 20 days during the experimental period. Contact microradiograph of the second molar region of the mandible showed that the cancellus bone as well as the endosteal surface of the cortical bone were progressively resorbed soon after the start of low calcium feeding. At day 9, the amount of bone was reduced to about half of the control rats and 80% of the bone was diminished at day 20. In spite of the severe bone resorption, the alveolar bone proper that surrounds the molar sockets and a few cancellus bone were seen remaining and the occlusal function of the molar tooth seemed to be maintained. These results suggest that the alveolar bone quickly responded to the low calcium diet resulting in bone resorption and that the bone in the supporting tissues of the molar tooth seems to be not affected by the calcium deficiency.

Alveolar Bone Loss↗
PubMed1998

[The occlusal force distribution on the dental arch restored with implants in uni-lateral molars missing].

The object of this study was to discuss the occlusal force distribution on the dental arch before and after wearing implant-supported prostheses. The occlusal force was measured on four patients missing uni-lateral molars restored with 14 dental implants. The occlusal force distribution was represented as the occlusal force bearing rate (B.R.) which is the percentage of occlusal force on each portion to the total occlusal force. B.R. of the implant portion, of the non-implant side molar portion and of the anterior portion were calculated on four patients. B.R. of the premolar implant portion and of the molar implant portion were calculated on two patients. The pressure sensitive sheets and the image scanner (Dental Prescale 50H type R and Occluzer FPD 703, Fuji Photo Film Co.) were used in this study. The results were as follows: 1. The corresponding occlusal force was also born with the implant portion. Therefore, the total occlusal force increased, and the occlusal force distribution was extended to the same degree as the natural dentition after wearing the implant-supported prostheses. 2. The occlusal force and B.R. on the molar implant portion were considerably large regardless of wearing premolar implants. 3. The occlusal force and B.R. on the most distal implant in any molar portion were almost constant. These results suggested that the implant restoration should be useful for recovering occlusal functions, and that the most distal implant on the dental arch should have the sufficient bearing potential.

Adult↗
PubMed1975

[Mesiodistal inclination of permanent 2d molars Angles of bite].

Measurement of the angles formed by the axes of the second permanent molars on the plane of bite in premolar sector was carried out by profile teleradiographies of 50 young adults. These patients showed no abnormality likely to affect the molar alveolar processes in the saggital plane. The results were as follows: Open angle in front of the second upper molar with plane of bite:80degres. Open angle in front of the second lowermolar with plane of bite: 110degrees. Angle of bite of the second molars: 170degrees, identical with the angle of bite of the first molars.

Adolescent↗
PubMedDate not supplied

[Periapical surgery of the molars].

INTRODUCTION: If loss of a great number of teeth occurs, one molar in the lateral segment is of great importance. Contemporary techniques and materials provide extremely successful conservative treatment of pulpal diseases and apical periodontitis. In some cases, however, surgery is indicated. INDICATIONS: Indications for periapical surgery used to be a matter of double standards. If periapical surgery is indicated in incisors, it is performed without delay, but if it is indicated in molars, it is often exchanged for extraction. Surgical access in the region of upper and lower molars is specific in regard to much more frequently operated incisors due to anatomic structures at the surgical site. Canal filling techniques, implants, endodontic surgical procedures are of importance and can provide better healing. High quality canal filling is condition sine qua non in treatment of apical periodontitis. It is performed prior surgery, by conventional orthograde endodontic techniques, during surgery by orthograde technique and/or retrogradely. Implants provide better bone healing and are recommended in surgery of molar apex. Surgical packing has numerous advantages (better psychological and mechanical care). CONCLUSION: Good knowledge of anatomy and surgical techniques is a pre-requisite for molar apicoectomy. Careful establishment of indications and good relations with the patient provide good prognosis of this therapeutic method.

Apicoectomy↗
PubMed2000

Lingual nerve protection during surgical removal of lower third molars. a prospective randomised study.

A prospective randomised study was designed to evaluate the efficacy of protecting the lingual nerve by subperiosteal insertion of a retractor in 300 patients. All operations were performed under local anaesthesia and only one molar was removed at a time. In one group, the lower third molar was removed with protection of the lingual nerve and in another group, without protection. Molars which did not need to be sectioned were excluded from the study. The position of the molar, the degree of surgical difficulty and patient gender and age were also recorded. The results indicate 1.33% incidence of temporary lingual nerve dysaesthesia--this being low in comparison with other studies. No permanent disturbances were found. The intergroup percentage difference was not significant. It is suggested that routine application of a lingual protecting instrument during surgical removal of a third molar is not necessary in the hands of an experienced surgeon.

Adolescent↗
PubMed2000

Apical root resorption of upper first molars as related to anchorage system.

Night-time use of extra-oral traction for anchorage may cause jiggling, rotational and extrusional forces. The purpose of the study was to test the hypothesis that headgear forces in an anchorage system may increase the risk of radiographically detectable root resorptions on molar teeth. Twenty-one patients were selected among patients planned for orthodontic treatment, in which there was a need of anchorage in a full-bond appliance during a period of at least 6 months. An experimental group of 11 patients was given reinforcement anchorage in the maxilla with an extra-oral traction (cervical-pull) during night. Ten patients in a control group was given anchorage by a Goshgarian palatal bar, or by Class II-elastics. Periapical radiographs were taken of the upper first molars according to a standardised technique at the start of treatment, and at 3 and 6 months. Recordings included also patient compliance, force evaluation and the measurement of tooth movement. Significant reduction of root length was shown for some roots already after 3 months. However, mean root resorption after 6 months did not exceed 0.6 millimeter in any upper first molar root of the present sample. The degree of root resorption was similar in the experimental and the control groups. The hypothesis of a significant effect on root resorption of upper first molars by night-time use of extra-oral traction for a 6 month period was rejected. It is concluded that patients given anchorage by night-time use of extra-oral traction will show similar degrees of root resorption of the upper molars as those in which anchorage is given by a Goshgarian bar or Class II elastics.

Extraoral Traction Appliances↗
PubMed2000

Conventional cross-sectional tomographic evaluation of mandibular third molars.

OBJECTIVE: The purpose of this study was to locate the mandibular canal in relation to the impacted mandibular third molar by conventional cross-sectional tomography. METHOD AND MATERIALS: Conventional axially corrected cross-sectional tomograms of 347 successive impacted mandibular third molars of 234 patients referred for removal of the impacted teeth were acquired with a Scanora x-ray unit. The images were assessed for location of the mandibular canal and the impacted mandibular third molar. Descriptive analysis was performed. RESULTS: Examination of the tomograms revealed the alveolar nerve to have, in relation to the mandibular third molar, a lateral (buccal) course in 53.6% (n = 186), a course between the roots in 26.8% (n = 93), a lingual course in 13.0% (n = 45), and an inferior course in 6.0% (n = 21). Supplementary canals were found in 6.3% (n = 22). Two of the tomograms (0.6%) could not be evaluated, in 1 case because of incorrect patient positioning, resulting in an incorrectly adjusted transverse cut, and in the other case because of a mandibular carcinoma. CONCLUSION: Conventional axially corrected cross-sectional tomograms offer additional information in cases where there is a close relationship between impacted third molars and the alveolar nerve (superimposition of the roots and the canal, grooving, or a varied direction of the canal on the panoramic radiograph) and may contribute to a higher level of intrasurgical safety.

Anatomy, Cross-Sectional↗
PubMed2001

Enamel hypomineralization in permanent first molars. A clinical, histo-morphological and biochemical study.

Hypomineralization in the permanent first molars was common in a group of 516 Swedish 8-year-old children. Ninety-five children (18.4%) had at least one molar with demarcated opacity. The incisors frequently displayed opacities concomitantly. The mean number of hypomineralized teeth of the affected children was 3.2 (SD 1.8), of which 2.4 were first molars. Six and a half percent of the children had severe defects, 5% had moderate defects, while 7% had only mildly hypomineralized teeth. Fifteen percent had more than one tooth affected, indicating systemic causation. The affected children, especially the boys, were reported to have had more health problems, asthma in particular (but only 4 cases), during the first year of life. Breast feeding history was similar in children with and without enamel defects. The children with severely defected enamel had undergone dental treatment of their first molars nearly ten times as often as the children in the healthy control group at the age of nine. Behavior management problems and dental fear and anxiety were common compared to the controls. Undemineralized sections from 73 permanent first molars, extracted due to severe hypomineralization of the enamel, were examined in polarized light. The hypomineralized areas extended from the cusps cervically comprising about half of the buccal and lingual sides. The cervical border to normal enamel was well defined and mainly followed the lines of Hunter-Schreger. The hypomineralized zones were covered by thin well-mineralized enamel. The concentration gradients for F, Cl, Na, Mg, K and Sr in hypomineralized enamel were analyzed by means of Secondary Ion Mass Spectrometry (SIMS), and completed with an analysis of the main matrix elements O, P and Ca by means of X-ray microanalysis (XRMA). Hypomineralized enamel had a higher content of C. Ca and P concentration were lower compared with normal enamel. The mean Ca/P ratio in hypomineralized areas was significantly lower (1.4) than the mean Ca/P ratio in the adjacent normal enamel (1.8).

Adolescent↗
PubMed2002

Dental treatment, dental fear and behaviour management problems in children with severe enamel hypomineralization of their permanent first molars.

OBJECTIVES: To assess the demand for restorative treatment, dental anxiety and dental behaviour management problems among children with severe hypomineralization of their first molars (MIH). DESIGN: Case control study. SAMPLE AND METHODS: Data were compiled from the dental records of 32 9-year-old children with severe enamel hypomineralization of their first molars and from 41 controls of the same age group concerning dental health, a number of restorative treatments, use of local anaesthesia and clinical behaviour management problems (BMP). A questionnaire containing specific questions on children's experiences of dental care and the Children's Fear Survey Schedule-Dental Subscale (CFSS-DS), was answered by the parents. RESULTS: The children in the study group had undergone dental treatment of their first molars nearly 10 times as often as the children in the control group. Repeated treatments of these teeth at brief intervals were common. The dental treatment was often undertaken without the use of local anaesthesia, and BMP, and dental fear and anxiety (DFA) were more common than in the controls. CONCLUSIONS: Children with severe enamel hypomineralization of their first molars had had to undergo a considerable amount of dental treatment. It is reasonable to assume that experiences of pain and discomfort on repeated occasions were related to the occurrence of BMP in patients with MIH. An early treatment planning and prognostication based on increased knowledge of hypomineralized first molars is desirable. Local anaesthesia and other pain-reducing techniques, e.g. sedation, should be used when treating these teeth. Extraction should be considered in cases of extensive disintegration of the crown, in cases of frequently repeated treatments or when pulpal symptoms are hard to cure.

Anesthesia, Dental↗
PubMed1998

[Complaints and complications associated with removal of the mandibular third molar. A prospective clinical study].

OBJECTIVE: To study the incidence of complaints and complications after removal of the mandibular third molar and to evaluate the influence of this procedure on functioning of the patient during the first post-surgical week. DESIGN: Prospective, clinical. SETTING: Department of Oral and Maxillofacial Surgery, University Hospital Groningen. METHODS: Patients referred for removal of a mandibular third molar were asked to return one week after the procedure and to keep a daily record of the use of pain medication, duration of the pain and intensity of the pain. RESULTS: Removal of mandibular third molars resulted in an overall complication rate of 12%. Pain medication was used more frequently and for a longer period by patients with post-surgical complications. Due to complaints following the removal of the mandibular third molar, the mean absence from work was one and a half day. Work was generally resumed with decreased perceived efficiency. CONCLUSION: After this commonly performed procedure in dento-alveolar surgery most of the patients were hampered as a result of pain during the first four post-surgical days. Over 10% of the patients developed complications leading to more frequently and prolonged use of pain medication. Removal of the mandibular third molar gave rise to complaints which influenced the patients relatively strong in their daily functioning.

Absenteeism↗
PubMed1992

[Secondary retention of permanent molars. I. Clinical, radiologic and histologic characterization].

The clinical, radiographical and histological aspects of secondary retention in permanent molars were studied in a group of 53 patients with 81 secondarily retained permanent molars. First molars turned out to be affected most frequently. The mean infraocclusion at the patients' first visit was 4.3 mm. After six months, infraocclusion had increased in adolescents. It seemed to be stable in adults. Tilting of adjacent teeth was observed in 39 cases of secondary retention. A solid, clear percussion sound and a partial absence of the periodontal ligament space on radiographs was only noted in less than 20% of the affected molars, while histological examination of 38 removed molars revealed that local areas of ankylosis were present in all cases. During a follow-up period of four years, six new cases of secondary retention were observed in the same population.

Adolescent↗