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PubMed1987

Neuroendocrine regulation of anterior pituitary function in patients during and after molar pregnancy.

Only partial studies evaluating the endocrine profile in molar pregnancy have been performed. In order to characterize the neuro-endocrine pattern during and after molar pregnancy, we studied the basal hormonal levels of hCG, human placental lactogen (hPL), FSH, GH, TSH, free thyroxine index (FTI), oestradiol-17 beta (E2), and progesterone (PG), as well as the anterior pituitary response to TRH, GnRH, and hypoglycaemia induced by insulin in 7 patients during molar pregnancy and one week after molar abortion. hCG showed significantly higher serum levels during rather than after molar pregnancy and hPL was detectable in only 4 patients during, but in none after molar pregnancy. FSH values were in the follicular phase range before and after molar abortion (12.7 +/- 0.8 and 12.7 +/- 3.5 IU/l). PRL had elevated basal levels before and after molar abortion; 103.0 +/- 16.5 and 43 +/- 10.6 micrograms/l, respectively (P less than 0.05). GH levels were distinctly elevated in 3 patients during molar pregnancy; after molar abortion, the basal GH values were normal in all patients less than 10 micrograms/l. Basal cortisol and TSH levels were in the normal range before and after molar abortion. The FTI was above the normal range in 3 patients during molar pregnancy, whereas after molar abortion the values were normalized. E2 levels were elevated before and after molar abortion, 1881 +/- 477 and 96.5 +/- 39.2 ng/l, respectively (P less than 0.01). PG levels before and after molar abortion were 30.9 +/- 5.4 and 10 +/- 6.7 micrograms/l, respectively (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed2001

Root and canal morphology of Burmese mandibular molars.

AIM: To study the root canal morphology of Burmese mandibular molars using a canal staining and tooth clearing technique. METHODOLOGY: Mandibular molars (331) were collected from indigenous Burmese patients and designated; first (139), second (134), third (58) molars. Following pulp tissue removal and staining of the canal systems with Indian ink, the teeth were decalcified and rendered clear with methyl salicylate. Under magnification (x3), the following features were evaluated: (i) root number and morphology, (ii) number of canals per root, (iii) root canal configuration (Vertucci's classification), (iv) number of apical foramina per root, (v) number and location of lateral canals and (vi) the presence of intercanal communications. RESULTS: Most of the mandibular molars had two separate roots (90% in first molars, 58% in second molars, 53% in third molars) and three-rooted teeth were (10%) confined to first molars. C-shaped roots occurred in 22.4% of mandibular second molars and a further 14.9% had two fused roots. The majority (81-100%) of conical distal roots possessed a simple type I (single canal) configuration. Whilst the canal system of mesial roots was more complex: 52-85% contained two canals, of which type II (two orifices, one foramen) and type IV (two separate canals) were the most prevalent. A broad range of 6.5-70% had intercanal communications. Fused/single-rooted molars had a wide variety of canal system types but intercanal communications were rare except in C-shaped roots (33%) of second molars. The majority of roots of all molars contained one or two apical foramina (91-96%) and the apical third had the highest prevalence of lateral canals. CONCLUSIONS: There was a high prevalence of three-rooted mandibular first molars and C-shaped roots/canals in mandibular second molars from a Burmese population. Conical roots tend to have simple canal systems, whilst flatter/broader roots have more complex canal systems.

Asian People↗
PubMed2002

Periodontal pathology associated with asymptomatic third molars.

PURPOSE: We report the prevalence of periodontal probing depth (PD) as a clinical measure of the extent of periodontitis associated with asymptomatic third molars at the initial examination in a cohort of patients enrolled in an institutional review board-approved longitudinal clinical trial. PATIENTS AND METHODS: Three hundred twenty-nine healthy patients were enrolled during a 30-month period. Full mouth periodontal probing that included third molars was conducted to determine periodontal status. Panoramic radiographs were taken to assess the degree of eruption of the third molars and the angulation of third molars compared with the adjacent second molar. Vertical bitewing radiographs were analyzed to detect alveolar bone levels relative to the cementoenamel junction on the distal of second molars. RESULTS: Twenty-five percent (82 of 329) of all enrolled patients, and 34% (14 of 41) of black patients, had at least one PD equal to or greater than 5 mm on the distal of a second molar or around a third molar. PD equal to or greater than 5 mm was associated with periodontal attachment loss of at least 1 mm in every patient; PD equal to or greater than 5 mm was associated with attachment loss equal to or greater than 2 mm in 80 of 82 patients. A higher proportion of patients 25 years old or older had a PD equal to or greater than 5 mm on the distal of second molars or around third molars compared with patients younger than 25 years (33% vs 17%, P =.002). The distals of second molars and third molars in the mandible were affected more often than in the maxilla (25% vs 5%, P =.0001). CONCLUSIONS: Our data indicating that 25% of patients with retained asymptomatic third molars have considerable periodontal pathology in the third molar region were unexpected. National epidemiologic surveys indicate a much lower rate of periodontitis in the population younger than 35 years.

Adolescent↗
PubMed1984

Longitudinal study of three views of mandibular third molar eruption in males.

A longitudinal study, using three views simultaneously, was conducted on twenty North American black males to investigate mandibular third molar eruption. Each subject had two third molars present. Forty third molars were studied. Lateral, posteroanterior, and oblique (45 degrees left and right) cephalograms, along with plaster casts, were used. The following observations on the third molars were made; the age at which they can be identified; angulation of the occlusal surface; eruptive path, including the vertical, anteroposterior, and buccolingual positions; and the age of delineation between being unerupted or impacted, including factors related thereto. The Fisher's exact test from the SPSS package and the central tendency were the statistical instruments used to aid in interpreting the data. In some persons the crypt of the developing third molar was seen as early as 7.5 years and the occlusal surface was identified as early as age 8 years, with a mean of 9.75 years. Third molars usually form in the ramus with the distal cusp above the occlusal plane, the occlusal surface of the molar has a great cant facing anteriorly, the tooth descends below the occlusal plane, and appears to upright around 14 to 16 years of age. The impaction of the mandibular third molar is a complex multifactorial mechanism. The wide buccal location of mandibular third molars and the inadequate anteroposterior space between the distal surface of the second molar and the anterior surface of the ramus are important factors in third molar impaction. This study does not support the concept of early prediction of third molar impaction and enucleation of the asymptomatic developing third molars. If possible, the final decision for extraction of asymptomatic mandibular third molars that appear to be impacted should be delayed until after the age of 16 years.

Adolescent↗
PubMed1990

An SEM investigation of the mesiolingual canal in human maxillary first and second molars.

The mesiolingual orifices of 21 maxillary first molars and 37 maxillary second molars were examined with the scanning electron microscope. The mesiobuccal roots of these teeth were also typed by means of a clearing technique. The results demonstrated that 90% of first molars and 70% of second molars had two canals in the mesiobuccal root. Type 3 canal systems occurred in 33% of first molars and 35% of second molars. Eighty-one percent of first molars and 59% of second molars had a separate mesiolingual canal orifice. The mean diameter of the mesiolingual orifice was 0.49 mm in first molars and 0.42 mm in second molars. The mean distance of the mesiolingual orifice from the mesiobuccal orifice was 2.31 mm in first molars and 2.06 mm in second molars. In type 3 roots, the average distance of the mesiolingual foramen to the anatomic apex was 2.0 mm for first molars and 1.45 mm for second molars.

Adolescent↗
PubMed2004

Does space in the jaw influence the timing of molar crown initiation? A model using baboons (Papio anubis) and great apes (Pan troglodytes, Pan paniscus).

Radiographic and histological studies of baboon (Papio hamadryas, P. anubis) and chimpanzee (Pan troglodytes) permanent tooth development have found that periods of molar crown mineralization overlap markedly in chimpanzees but are staggered in baboons. Here we test the hypothesis that these intertaxon differences in molar initiation are primarily due to the space available in the mandibles of each species for these teeth. This study includes radiographic, linear measurement, and three-dimensional (3D) coordinate landmark data taken from baboon (Papio anubis n=51) and great ape (Pan paniscus n=43, P. troglodytes n=60) mandibles and permanent molars across a broad developmental range for each taxon. Unexpectedly, 3D multivariate statistical shape analysis of the molar crypt, crown, and root data shows that all three species trajectories of molar row shape change are indistinguishable from each other. Qualitative analysis of these 3D data reveals subtle and inconclusive intergeneric differences in the space maintained between adjacent molars during growth. The space distal to each newly initiated molar is slightly greater in the baboon. Bivariate analyses comparing molar row and mandibular corpus proportions in Papio and Pan fail to show clear or consistent taxonomic differences in the ratio of space afforded developing molars in the alveolar bone. Thus, there is a poor correlation between mandibular proportion and both intermolar spacing and 3D molar development pattern. Contrary to earlier studies, these results suggest that pattern of molar crown initiation and temporal overlap of adjacent mineralizing crowns is not significantly different between Papio and Pan. This may be due in part to the inclusion here of not only 3D molar crown data but also 3D molar crypt data. This study strongly refutes the hypothesis that space available in the mandible directly underlies different times of permanent molar crown initiation between Papio and Pan.

Animals↗
PubMed2003

Functional and phylogenetic implications of molar flare variation in Miocene hominoids.

Comparative analyses of molar shape figure prominently in Miocene hominoid evolutionary studies, and incomplete understanding of functional and phylogenetic influences on molar shape variation can have direct consequences for the interpretation of fossil taxa. Molar flare is a shape trait whose polarity, phylogenetic distribution, and functional significance have been sources of contention. To clarify the determinants of molar flare variation in the hominoid radiation, a combination of statistical methods was employed to investigate the effects of diet, phylogeny, and geologic age upon several measures of molar shape, to identify interactions among these factors, and to estimate their relative influence. Classic indices of molar crown shape and cusp relief are highly significantly associated with diet and show no clear phylogenetic or temporal patterning. Correlations with diet are insignificant when phylogenetic effects are controlled, a result which is interpreted as an artifact of the distribution of folivory in the Miocene hominoid radiation. Possession of pronounced molar flare was found to be the primitive condition for Miocene hominoids, but molar flare reduction cannot be considered a crown hominoid synapomorphy. Molar flare is strongly correlated with geologic age but differs significantly among dietary categories when the effects of time are controlled. Among contemporaneous taxa, hard-object feeders consistently show the highest levels of flare. Molar flare reduction is hypothesized to arise from realignment of cusp positions to maximize molar shearing and increase working occlusal surface area, while variation in flare among contemporaneous taxa may be due, at least in part, to enamel thickness variation. The pronounced molar flare of Otavipithecus is interpreted as a primitive retention, although alternative dietary and phylogenetic interpretations cannot be excluded. A dramatic reversal of molar flare reduction in Mio-Pliocene hominins is interpreted as a synapomorphy of the crown hominin clade, thus supporting the hominin status of the Lukeino hominine. The last common ancestor of the Pan-Homo clade is predicted to have possessed relatively non-flaring molars, and implications of this hypothesis for early hominin recognition are discussed.

Anatomy, Comparative↗
PubMed1996

Pathoses associated with mandibular third molars subjected to removal.

OBJECTIVES: To measure the prevalence of disease of mandibular third molars referred for removal and to estimate the risk for development of pathoses for two cues. STUDY DESIGN: A prospective cohort study on molars subjected to removal was performed. The prevalence of different diseases and the patient's age, angular position, and degree of impaction of the molars were registered. Odds ratio for molars with different positions and impaction states were estimated. RESULTS: Pericoronitis was found in 64% of cases, caries in the third molar in 31%, periodontitis in association with 8%, caries in the second molar in 5%, and root resorption of the second molar with 1% of the molars with pathoses. Odds ratio was highest for distoangular molars (5.8) and for molars partially covered by soft tissue (6.7). CONCLUSIONS: The odds ratio is about 22 and 34 times higher for molars partially covered by soft tissue than for molars completely covered by soft or bone tissue. For distoangular molars the odds ratio is 5 to 12 times higher than for molars in other positions.

Adolescent↗
PubMed1994

The topography of the furcation entrance in Chinese molars. Furcation entrance dimensions.

The purpose of the present study was to document the furcation entrance dimensions (FEDs) of the maxillary and mandibular 1st and 2nd molars and relate them to the choice of periodontal therapy. Study samples consisted of 89 maxillary molars (49 1st and 40 2nd molars) and 93 mandibular molars (50 1st and 43 2nd molars). All the FEDs of the molars were examined and measured under a stereomicroscope at 2.5 x equipped with a Bioscan OPTIMAS Image Analyzer (BOIA). The results may be summarized as follows. (1) The mean FEDs in the buccal, distal and mesial furcations of maxillary 1st and 2nd molars were 0.74 mm, 0.99 mm and 1.04 mm in the 1st molars, and 0.63 mm, 0.67 mm, 0.90 mm in the 2nd molars, respectively. In the buccal and lingual furcations of mandibular 1st and 2nd molars, they measured 0.88 mm and 0.81 mm, and 0.73 mm and 0.71 mm, respectively. (2) The %s of FEDs of 0.56 mm or less (the tip width of a Cavitron tip being 0.56 mm) in the buccal, distal and mesial furcations of maxillary 1st and 2nd molars, accounted for 32%, 8% and 6% of 1st molars, and 40%, 40% and 18% of 2nd molars. In the buccal and lingual areas of mandibular 1st and 2nd molars, they accounted for 16% and 26%, and 35% and 33% of the furcations, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2006

[Possibilty of the lower third molar eruption--radiographic analysis].

BACKGROUND/AIM: To assess the possibility of the eruption of the lower third molar on the basis of the measured parameters: retromolar space, mesiodistal crown width of a molar and the third molar angulation. METHODS: The investigation included 104 patients both sexes (43 boys, and 61 girls), 16 to 25 years old (mean age, 18 years). It was performed using the orthopanthomographic radiographs analysis of those patients. Each radiograph was covered by tracing paper, and the contoures of the following anatomic details were drawn: a) the crown and root contours of third molars, upper and lower central incisors, distal molars in occlusion, anterior edge of ramus mandible, b) lines: 1. the occlusal plane, 2. the line of retromolar space, 3. the mesiodistal crown width of third molar, 4. the axial shaft of the third molar and the distal angle between occlusal plane and the axial shaft of the third molar. The values were measured with an orthodontic caliper: the diameter of retromolar space, diameter of mesiodistal width, the value of distal angle between occlusal plane and axial shaft of molar. RESULTS: A favourable angulation of the lower third molar (more than 60 degrees) was found in, boys (left 27.90%, right 32.55%), girls (left 39.34%, right 37.77%). A favourable relationship between the diameters of mesiodistal width of the third molar and retromolar space was found in, boys, (left 13.59%, right 16.27%), girls, (left 8.19%, right 14.75%). A favourable relationship between the diameters of mesiodistal width of the third molar and the retromolar space and the angulation was found in boys, (left 9.30%, right 11.62%), girls, (left 6.56%, right 9.83%). CONCLUSION: There was not any statistically significant difference found between the relation of the retromolar value, third molar mesiodistal diameter, or of the third molar angulation to the left and the right side nor of their mutual relations in comparing boys and girls. A favourable prognosis was found in 9.33% of the patients.

Adolescent↗
PubMed2006

Intraoral maxillary molar distalization.

OBJECTIVE: To evaluate the maxillary molar distalization and anchorage loss in two groups, one before (MD 1 group) and one after (MD 2 group) eruption of second maxillary molars. MATERIALS AND METHODS: After a sample size calculation, 20 patients were recruited for each group from patients who fulfilled the following criteria: no orthodontic treatment before distal molar movement, Class II molar relationship defined by at least end-to-end molar relationship, space deficiency in the maxilla, and use of an intra-arch NiTi coil appliance with a Nance appliance to provide anchorage. Patients in the MD 1 group were without any erupted second molars during the distalization period, whereas in the MD 2 group both the first and second molars were in occlusion at start of treatment. The main outcome measures to be assessed were: treatment time, ie, time in months to achieve a normal molar relation, distal movement of maxillary first molars, and anterior movement of maxillary incisors (anchorage loss). The mean age in the MD 1 group was 11.4 years; in the MD 2 group, 14.6 years. RESULTS: The amount of distal movement of the first molars was significantly greater (P < .01) and the anchorage loss was significantly lower (P < .01) in the group with no second molars erupted. The molar distalization time was also significantly shorter (P < .001) in this group, and thus the movement rate was two times higher. CONCLUSIONS: It is more effective to distalize the first maxillary molars before the second molars have erupted.

Adolescent↗
PubMedDate not supplied

Long-term outcomes of primary molar ferric sulfate pulpotomy and root canal therapy.

PURPOSE: The purpose of this study was to compare long-term outcomes of ferric sulfate pulpotomy (FS) and primary tooth root canal therapy (RCT) in vital pulps of deciduous molars exposed to caries lesions. METHODS: A total of 291 molars were treated in 130 children. One hundred and eighty-two molars received FS and 109 received RCT by random selection. RESULTS: At 3-year re-assessment, 29 molars (15 FS, 14 RCT) were available for clinical and radiographic examination. Two independent pediatric dentists evaluated periapical radiographs of the treated molars. Molars were classified 1 of 4 outcomes: (1) N = normal treated molar; (2) H = nonpathologic radiographic change present; (3) P(o) = pathologic change present, follow-up in 6 months; (4) P(x) = pathologic change present extract immediately. Survival analysis was applied. A good level of agreement between raters was found for molars with outcome P(x) (K = 0.79). No difference in radiographic outcomes was demonstrated 3 years after treatment (chi2 = 1.4). Survival analysis demonstrated a 3-year survival probability of 0.62 for FS-treated molars and 0.92 for RCT molars. Survival of RCT molars was significantly greater than for FS molars (Wilcoxon: P = .01; log-rank: P = .02). CONCLUSIONS: RCT-treated molars demonstrated significantly greater survival than FS-treated molars 3 years after treatment.

Child, Preschool↗
PubMed2005

Mandibular third molar removal: patient preferences, assessments of oral surgeons and patient flows.

UNLABELLED: Mandibular third molar removal is one of the most common treatments conducted at oral and maxillofacial surgery clinics in Sweden. During the 1980's and 1990's, 20-25,000 mandibular third molars were removed annually which represents about 60% of the total operation volume. Removals performed in private specialist clinics and general dental clinics are not included in these figures. The aims of the present studies on mandibular third molars were to: 1) study values that reflect patients' preferences about possible outcomes of removal and non-removal; 2) make comparisons between Sweden and Wales with respect to patient's preferences; 3) study assessments of oral surgeons' indications for molars to be removed; 4) describe patient flows in the care process of removal. The multi-attribute utility (MAU) method was used to quantify patients' preferences about outcomes following removal and non-removal. Whilst there were clear cultural and economic differences between the Swedish and the Welsh, there was a high degree of correlation in patients' ranking of the different outcomes for patients from the two countries (rs = 0.93, P<0.001). Generally, situations describing the outcomes of non-removal had a higher ranking than those describing the outcomes of removal i.e. patients seemed to prefer non-removal. Oral surgeons at seven specialist clinics registered data for 666 patients i.e. patient age and sex, the angular position and extent of eruption of the molar and whether or not there was an associated disease related to the molar proposed for removal. The indication for the removal was assessed on a Visual Analogue Scale (VAS), and the recorded results found to show a great variety. The mean VAS for removal of molars without disease was significantly lower than that for molars with associated disease. The differences between the mean VAS for molars with one disease compared with molars with two or three diseases were not significant. The patients' age was the only factor that had a significant effect on the assessment of the indication for molars without disease. The indication was higher for patients of the youngest age group than for patients of the oldest age group (P<0.05). In four specialist units in southern Sweden, the patient flows (the number of visits and what the visits comprise of) was registered for 361 patients. All details were recorded from arrival of the referral to the unit to performed mandibular third molar surgery. Eight different patient flows were found. The number of patient visits varied from one to three. For about 60 percent of the patients, attached radiographs to the referral were considered not appropriate and had to be completed, e.g. to be retaken. For a minority of the patients, the radiographic examination was completed at the radiological clinic included in the specialist unit and, in the oral and maxillofacial clinic for the others. The number of patient visits seemed not to depend on whether the attached radiographs were judged to be appropriate or not. IN CONCLUSION: Patient preferences seem to be more stable than the preferences of oral surgeons across the boundaries. Patients prefer outcomes of third molar non-removal as compared to outcomes following removal. Different patient flows may influence the cost-effectiveness in mandibular third molar surgery.

Adolescent↗
PubMed2005

Persistent gestational trophoblastic disease is rarely, if ever, derived from non-molar first-trimester miscarriage.

Traditional epidemiologic data suggest that persistent gestational trophoblastic disease (pGTD), may follow, and be derived from, either molar pregnancy, non-molar term pregnancy or first-trimester non-molar miscarriage. We examined a database of cases of possible or probable hydatidiform moles and proven pGTD derived from the Regional Trophoblastic Disease Unit, Charing Cross Hospital, London. There were 424 cases (6%), in whom the initial registered diagnosis was that of PHM or CHM but central histopathological review diagnosed a definite non-molar hydropic abortion (HA). In eight of the 424 (2%), although the histology of the most recent index pregnancy was that of non-molar miscarriage, there was a previous history of pregnancy affected by hydatidiform mole; two of these developed subsequent pGTD. Of a further 86 cases referred for a histopathological opinion prior to registration which demonstrated definite non-molar HA, none developed pGTD (zero of 510 (0%, 95% CI 0-0.7%)). During the same period there were 352 cases with pGTD requiring chemotherapy. In 31 cases, the only known pregnancy was the preceding apparent non-molar HA. However, of these, there were only three cases in whom the preceding histological products of conception had been centrally reviewed and were suggestive of non-molar pregnancy. However, in all three of these cases, the specimens were inadequate for definite exclusion of molar pregnancy. In one case in whom no material was available for review, molecular genetic analysis using restriction fragment length polymorphisms was carried out, and the choriocarcinoma was genetically derived from a previous molar pregnancy rather than the preceding HA. There were therefore no cases identified on the database of the trophoblastic disease unit of pGTD requiring treatment in whom the trophoblastic tumour could be genetically proven to have arisen from the preceding first trimester non-molar HA. We suggest that the risk of pGTD developing from a histologically confirmed non-molar HA is less than 1 in 50,000 and that the majority of pGTD cases previously reported to have been caused by a non-molar miscarriage probably represent disease due to an unrecognised early molar pregnancy.

Abortion, Spontaneous↗
PubMed1990

A comparison of results of second molar and first premolar extraction treatment.

The purpose of this study was to examine treatment results of maxillary and mandibular second molar extraction cases and compare them with treatment results of maxillary and mandibular first-premolar extraction cases. Records of 22 maxillary and mandibular second-molar extraction cases and 22 maxillary and mandibular first-premolar extraction cases were evaluated. For each case, pretreatment and posttreatment lateral cephalograms were traced and several cephalometric parameters were compared. From the pretreatment and posttreatment panoramic radiographs, angulations of the maxillary and mandibular third molars were evaluated. Average treatment time, in months, was recorded for both groups. The data obtained from each group were analyzed for statistical difference. The results showed that the two groups had fewer differences than indicated by advocates of second-molar extractions. Analysis of the cephalometric data demonstrated only a few statistical differences between the groups. The maxillary and mandibular incisors in the premolar group were retracted a significantly greater amount than in the second-molar group. The maxillary and mandibular first molars were protracted a greater amount in the premolar group than in the second-molar group. The lower lips in the premolar group were retracted a greater amount than in the second-molar group. The resulting facial profile after extraction of second-molars appears to be no different from that obtained after extraction of first premolars. The pantographic evaluation of the changes in third-molar angulation were not statistically different. In both groups, the maxillary third molars showed an improvement in third-molar angulation, while the mandibular third-molars showed an undesirable increase in angulation. The average treatment time for both groups was not statistically different.

Adolescent↗
PubMed2001

Root and canal morphology of Burmese maxillary molars.

AIM: To investigate the root and canal morphology of Burmese maxillary molars using a canal staining and tooth clearing technique. METHODOLOGY: Maxillary molars (239) were collected from indigenous Burmese patients and designated; first (90), second (77), third (72) molars. Following pulp tissue removal and canal system staining with Indian ink, the teeth were decalcified with 10% nitric acid, dehydrated and cleared with methyl salicylate. The following features were evaluated: (i) number of roots and morphology; (ii) number of canals per root: (iii) root canal configuration (Vertucci's classification); (iv) number of apical foramina per root; (v) number and location of lateral canals; and (vi) the presence of intercanal communications. RESULTS: All first and second molars had three separate roots, whilst third molars had one of five different root forms, of which three separate (25%) or fused (31%) roots were most prevalent. The majority of palatal (100%) and disto-buccal (96%) roots possessed one canal (type I). The prevalence of mesio-buccal roots with two canals decreased from first to third molars (68%, 49%, 39%, respectively); type II (two orifices, one apical foramen) and IV (two orifices, two apical foramina) configurations were the most common. Single/fused rooted third molars had a range of number and type of canals. Most roots in all molars had one apical foramen, those with four apical foramina were confined to third molars. Intercanal communications were most prevalent in mesio-buccal roots and two/three fused rooted third molars. Lateral canals were most prevalent in the apical third of the roots of all molars. CONCLUSIONS: The mesio-buccal roots of Burmese maxillary molars possessed a variety of canal system types. Over 50% of the first and second molars had a second mesio-buccal canal, of which over 20% had intercanal communications. The palatal and disto-buccal canals mainly had type I canals. Lateral canals were equally prevalent in all tooth types but were most common in the apical third.

Adult↗
PubMed2006

Sagittal, vertical, and transverse changes consequent to maxillary molar distalization with the pendulum appliance.

INTRODUCTION: The purpose of this study was to evaluate the skeletal and dental changes in patients who underwent distalization of their maxillary molars with pendulum appliances. METHODS: The sample consisted of 31 patients (initial mean age, 14.58 years) with Angle Class II molar relationships and all permanent teeth up to the second molars. The maxillary molars were distalized with pendulum appliances for a mean period of 5.87 months. Lateral cephalograms, 45 degrees oblique radiographs, and dental casts were obtained before and after distalization. Changes produced by the pendulum appliance were analyzed with paired t tests. RESULTS: Maxillary first molar distalization accounted for 63.5% of the space opening; mesial movement of the maxillary first premolars contributed 36.5% of the space. The mean space opening on lateral cephalograms was 7.25 mm, and the rate of molar movement was 1.23 mm per month. The mean distalization of the maxillary molars was 4.6 mm, with a mean distal crown tipping of 18.5 degrees The maxillary molars experienced expansion, with a smaller effect on the first molars than on the second molars. The pendulum appliance produced symmetrical expansion, with a rate of 1.04 mm per month on the right and 1.10 mm per month on the left. CONCLUSIONS: The pendulum appliance is effective for distalization of the maxillary molars and the establishment of a Class I molar relationship in a relatively short time. However, caution is needed to control collateral effects, including mesial movement of the first premolars and distal tipping of the molar crowns.

Adolescent↗
PubMed1995

Impaction status of third molars in Jordanian students.

The status of third molars was studied radiographically in 108 male and 124 female Jordanian students (mean age, 20.4 years). The results showed that 9.1% of third molars were congenitally missing. Approximately 73% of the subjects had all four third molars, 12% had three third molars and 11% had two third molars. Only 1.7% had agenesis of all third molars. Third molar agenesis showed predilection for the maxilla over the mandible. There was no significant sexual dimorphism in the agenesis of third molars. Impaction of third molars was found in one third of the subjects with predilection (5.2%) to the maxilla. The proportion of impaction in males was 17.4% and in females 16.2%. Angular position of mandibular third molars revealed that half of the teeth were mesially tilted (average angle 20 degrees +/- 13 [SD] and 41% were in vertical position. A highly significant correlation (r = 0.79, p < 0.001) in the inclination angles was observed between the right and left side of the mandible. The level of eruption of third molars showed 58% of the teeth were fully erupted to occlusal plane, whereas 26% were embedded below the cervical line of adjacent second molar (level C). Males showed a significantly higher frequency (p < 0.001) of level C eruption than females. Results indicated that 11.6% of the subjects or 8.4% of the third molars had incomplete root formation, of which two thirds to one thirds root completion was at a ratio of 4.3:1. The clinical significance of these results is discussed.

Adolescent↗