Pulp canal obliteration after Le Fort I osteotomy

A longitudinal study of 51 patients was carried out to determine the frequency of pulp canal obliteration (PCO) after Le Fort I osteotomy for the correction of dentofacial anomalies and to analyse pre- and peroperative factors influencing the development of PCO. PCO developed in 14 (2.3%) of 617 maxillary teeth followed for an average period of 28 months (range 11-59). The highest frequency of PCO was demonstrated in canines (6.0%) and premolars (4.4%). Total PCO was present in 9 teeth and partial PCO in 5 teeth. PCO was more frequent among teeth adjacent to a vertical interdental osteotomy than in teeth with no relation to a vertical osteotomy (p less than 0.0001). Change in blood supply after the operation was suggested to be responsible for PCO, although it might have been effected by the combined surgical and orthodontic treatment. Long-term follow-up, including periapical radiographs, of teeth with PCO is suggested, as pulp necrosis may develop many years after surgery.     

Pulp canal obliteration after Le Fort I osteotomy

Abstract A longitudinal study of 51 patients was carried out to determine the frequency of pulp canal obliteration (PCO) after Le Fort I osteotomy for the correction of dentofacial anomalies and to analyse pre- and peroperative factors influencing the development of PCO. PCO developed in 14 (2.3%) of 617 maxillary teeth followed for an average period of 28 months (range 11–59). The highest frequency of PCO was demonstrated in canines (6.0%) and premolars (4.4%). Total PCO was present in 9 teeth and partial PCO in 5 teeth. PCO was more frequent among teeth adjacent to a vertical interdental osteotomy than in teeth with no relation to a vertical osteotomy (p< 0.0001). Change in blood supply after the operation was suggested to be responsible for PCO, although it might have been effected by the combined surgical and orthodontic treatment. Long-term follow-up, including periapical radiographs, of teeth with PCO is suggested, as pulp necrosis may develop many years after surgery.     

Blood-flow change and recovery of sensibility in the maxillary dental pulp after a single-segment Le Fort I osteotomy

OBJECTIVE: To examine blood-flow change and recovery of sensibility in the dental pulp of maxillary incisors in patients undergoing a single-segment Le Fort I osteotomy. STUDY DESIGN: Fifty-four maxillary incisors in 14 patients were examined preoperatively and at 1 to 7 days, 14 days, 3 months, 6 months, and 12 months postoperatively. The pulpal blood flow (PBF) was measured by laser Doppler flowmetry, and the pulpal sensibility (PS) was investigated by electrodiagnostics. RESULTS: The mean PBF dropped to its lowest value at 1 day postoperatively and subsequently increased except for a temporary drop on day 4. The PS was negative in all the examined teeth from 1 day to 14 days after surgery. Subsequently, the rate of the teeth with positive PS increased. At 3 months postoperatively, the PS recovered in half of the examined teeth. The PBF value on day 1 was significantly higher in the teeth with positive PS at 3 months postoperatively than in those with negative PS at 3 months postoperatively. CONCLUSION: These results suggest that the decrease of the PBF in the maxillary incisors on 1 day after a single-segment Le Fort I osteotomy may affect the recovery of the PS in the short term after surgery.     

Laser Doppler flowmetry for assessment of anterior mandibular teeth in conjunction with bone harvesting in the symphysis: a clinical pilot study

PURPOSE: To evaluate the pulp sensitivity and vitality of mandibular incisors and canines before and after bone harvesting in the symphysis. MATERIALS AND METHODS: In 20 patients requiring bone grafts from the symphysis, pulp sensitivity (carbon dioxide [CO2]) and pulpal blood flow (laser Doppler flowmetry [LDF]) of mandibular incisors and canines were evaluated preoperatively, postoperatively, and 6 months after surgery. Teeth were allocated to 1 of 3 groups according to their initial and final reaction to CO2 (group A = teeth with a positive reaction throughout the study, group B = teeth that exhibited a sensitivity change from positive to negative, and group C = teeth with a negative reaction throughout the study). RESULTS: Preoperative flux measurements (LDF) did not differ between groups A, B, and C. Teeth with sensitivity changes (group B) showed the greatest decrease (a statistically significant decrease) of pulpal blood flow over time, whereas teeth in groups A and C demonstrated an insignificant reduction of flux over time. DISCUSSION AND CONCLUSIONS: LDF was purely used as an experimental tool in the present study. Pulpal blood flow measurements using LDF demonstrated a decrease of flux over time in anterior mandibular teeth following bone harvesting in the symphysis. A significant change of flux, however, was only observed for teeth that also demonstrated a loss of pulp sensitivity during the same study period. Loss of pulp sensitivity appeared to be correlated to a significant decrease of blood flow assessed by LDF.     

Histological and bacteriological study of pulps extirpated after luxation injuries

Abstract In a material of 637 luxated permanent teeth, it was found that 26 teeth (4.2%) which initially demonstrated the classical signs of pulp necrosis had reverted to normal appearance and sensibility at later examination, indicating that a revascularization and reinnervation process of the traumatized pulpal tissue had taken place. A histological and histobacteriological analysis was made of 66 pulps in the same population that had been extirpated due to suspected pulpal necrosis after injury, in order to examine whether similar changes could also have occurred in these teeth. It was found that the pulps studied were either non-infected (n = 27), infected (n= 11) or totally autolyzed (i.e. not enough tissue for histological examination (n = 28)). In contrast to teeth with autolyzed or infected pulp tissue, 12 of the 27 non-infected specimens showed signs of pulpal revascularization and/or apparent scattered cell survival. These pulps were assumed to have a potential for healing (i.e. revascularization and reinnervation of the pulp). Most clinical and radiographic parameters appeared not to be associated with pulpal infection of cell/tissue integrity. Only the length of the observation period and tenderness to percussion were found to be related to the histological status (i.e. presence or absence of pulpal infection, cellular versus acellular stroma). It was concluded that the present criteria for pulpal necrosis cannot discriminate between infected pulp necrosis and cases where healing might take place. Whether healing processes would actually lead to repair of the pulp could not be determined with the present material.     

Evaluation of the process of recovery of dental pulp after Le Fort I osteotomy

Le Fort I osteotomy has been established by many studies and is generally used, but hypoesthesia of the dental pulp, the most common complication, occurs in almost all patients. As such, we examined dental pulp sensibility, pulpal blood flow, and histological changes, to elucidate the process of functional recovery of dental pulp after Le Fort I osteotomy. Monkeys (Macaca fusucata) were used in this study. The animals underwent Le Fort I osteotomy in their unilateral maxillae. Histological and angiographic examinations were performed to observe the postoperative changes in the maxillae and dental pulp. Postoperative pulpal blood flow was examined using a laser Doppler flowmetry. Postoperative pulpal blood flow, by a laser Doppler flowmetry, and dental pulp sensibility, by electrodiagnostics, in patients who underwent Le Fort I osteotomy, were also examined. Although nerve fibers observed in the dental pulp of the maxilla degenerated and disappeared by one week postoperatively, they reappeared sparsely from two to three months after osteotomy, and there were abundant nerve fibers by one year postoperatively. In the angiographic examination, blood supply to the maxillary dental pulp was maintained throughout the postoperative period. In the examinations of laser Doppler flowmetry and dental pulp electrodiagnostics, ischemia in the dental pulp for three or four days after osteotomy might delay the recovery of dental pulp sensibility. These results suggested that blood flow in dental pulp at three or four days after surgery may affect the recovery of dental pulp sensibility.     

Replantation of 400 avulsed permanent incisors. 2. Factors related to pulpal healing

Abstract Four hundred avulsed and replanted permanent teeth were examined for pulpal healing. In 110 teeth, the apical foramen was either open or half-open. In 16 teeth, the pulps were extirpated prophylactically. Thus, pulpal revascularization was considered possible in 94 teeth. Revascularization occurred in 32 teeth (34%). Pulp necrosis could usually be demonstrated after 3 weeks. Positive pulpal sensibility and radiographis signs of pulp canal obliteration were usually observed after 6 months. The effect of various clinical factors was examined, such as sex, age, type of tooth replanted, stage of root formation, type and length of extra-alveolar storage, clinical contamination of the root surface, type of cleansing procedure of the root surface, type and length of splinting and the use of antibiotics. Finally, the width of the apical foramen and the length of the root canal were measured on radiographs taken at the time of injury. A multivariate statistical analysis revealed that pulpal revascularization was more frequent in teeth with shorter distances from the apical foramen to the pulp horns. Furthermore, that wet storage (saliva and/or saline) for more than 5 min decreased the chance of pulpal revascularization; whereas dry extraalveolar storage had a monotonous effect on pulpal revascularization, i. e. decreasing chance of revascularization with increasing length of the extraalveolar dry storage. Based on these findings, immediate replantation after brief cleansing in either tap water or saline is recommended.     

Effect of segmental Le Fort I osteotomy on maxillary tooth type-related pulpal blood-flow characteristics

Laser Doppler flowmetry (LDF) is a noninvasive method to assess pulpal blood-flow (PBF). Osteotomies may have segment-related losses of pulpal sensibility. OBJECTIVES: To determine the effect of segmental Le Fort I osteotomy on tooth-type related PBF values. MATERIALS AND METHODS: In 12 volunteers, maxillary incisors, canines, and premolars were investigated bilaterally by LDF to assess local PBF values before and after surgery. Perfusion units (PU) were in 3 sessions, on the day before surgery and at 4 and 56 days after osteotomy. RESULTS: Measurements before surgery were significantly higher than at 4 days after surgery for the canine (P <.01) and for the overall PBF values (P <.01). At 4 days assessment, PBF values of tooth types adjacent to vertical osteotomy cuts showed a significant decrease for the lateral incisors (P <.05), canines, and first premolars (P <.05), with no significant differences between the preoperative and postoperative values for tooth types not adjacent to vertical osteotomy cuts (P <.05). CONCLUSIONS: Segmental Le Fort I osteotomy induced a short-term and long-term decrease in maxillary PBF values of tooth types adjacent to vertical osteotomy cuts.     

Cone beam computed tomography evaluation of tooth injury after segmental Le Fort I osteotomy

The purpose of this study was to explore the incidence of injuries to the teeth at the vertical osteotomy line after segmental Le Fort I osteotomy by examination of postoperative cone beam computed tomography (CBCT) images. Data for this retrospective case study were collected using CBCT images of 132 patients with an indication for Le Fort I osteotomy with three-piece segmentation of the maxilla. Twenty-two patients (17%, 95% confidence interval 10–23%) had dental injuries. No patient had more than one dental injury. Thirty-three patients (25%, 95% confidence interval 18–32%) had bone dehiscence of the teeth (defined as the osteotomy line passing through the periodontal ligament). Six patients had bone dehiscence involving two teeth and one patient had bone dehiscence involving three teeth. In the group in which dental injuries occurred, the preoperative interdental distance at the vertical osteotomy line was significantly shorter than the interdental distance in the group without dental injuries. In conclusion, this study demonstrated that a preoperative interdental distance of more than 2.5 mm significantly reduced the possibility of tooth injuries adjacent to the vertical osteotomy line during Le Fort I osteotomy with three-piece segmentation of the maxilla.     

Blood-flow change and recovery of sensibility in the maxillary dental pulp during and after maxillary distraction: a pilot study

OBJECTIVE: To examine the change in blood flow and recovery of sensibility in the maxillary dental pulp during and after maxillary distraction. STUDY DESIGN: The subjects included 5 patients undergoing high Le Fort I osteotomy and maxillary distraction (D-group) and a reference group of 14 patients who underwent a common single-segment Le Fort I osteotomy, 1-stage maxillary advancement, and mandibular setback surgery (C-group). Eleven (D-group) and 54 (C-group) maxillary incisors were assessed preoperatively and at 1-7 days, 14 days, and 3 months postoperatively. Pulpal blood flow (PBF) was measured by laser Doppler flowmetry, and pulpal sensibility (PS) was investigated by electrodiagnostics. RESULTS: From postoperative days 1 to 5 (the latency period), the PBF tended to be higher in the D-group than in the C-group. From day 6 to 3 months postoperatively (during and after maxillary distraction), the PBF values of the 2 groups were similar. The PS remained negative up to 14 days postoperatively in both groups. However, at 3 months after the operation, a higher proportion (90.9%) of teeth in the D-group was positive for PS. CONCLUSION: These results suggest that maxillary distraction is a favorable technique for maintenance of PBF and recovery of PS in the maxillary teeth after surgery.     

The chin as a donor site in early secondary osteoplasty: a retrospective clinical and radiological evaluation.

26 unilateral cleft palate patients received an autogenous bicortical chin bone graft for early reconstruction of the alveolar process. In the evaluation of the donor site, 4% of the anterior teeth showed a negative pulpal sensibility, less than 1% a peri-apical granuloma and 12% pulp canal obliteration. The tooth buds of the canines showed developmental disturbances in 6%. Exposure of unerupted canines should be avoided, and a 5 mm safety margin is advised. Based on its architecture, topographic accessibility, minimal post-operative morbidity and absence of visible scars, the chin can be considered to be a very useful donor site in bone grafting procedures.     

Long-term evaluation of human teeth after Le Fort I osteotomy: a histologic and developmental study

Transient pulpal vascular ischemia and direct injury to the apices of the teeth have been implicated as the causes of degenerative and atrophic pulpal changes in experimental animals after Le Fort I osteotomy despite the presence of collateral circulation. The long-term clinical effect of these pathologic changes in human teeth has not been studied. Seventeen maxillary third molar teeth from 10 patients whose postsurgical follow-up ranged from 6 months to 78 months (mean, 40 months) were extracted. The long-term biologic effects of Le Fort I osteotomy on the pulp and on the development of teeth were retrospectively evaluated with clinical and standard histologic techniques. Normal teeth from patients who were not operated on were used as controls. Histologic examination revealed an intact pulpal circulation and minimal pathologic changes in the pulpal tissue. Clinical and radiographic studies showed that the growing teeth developed normally after surgery. The Le Fort I downfracture procedure had little discernible long-term effect on the pulp and on the development of human third molar teeth.     

Blood-flow and neurosensory changes in the maxillary dental pulp after differing Le Fort I osteotomies

PURPOSE: The objective of this study was to examine changes in blood flow and the recovery of sensibility in the maxillary dental pulp after two different types of maxillary osteotomies.Study design Nine patients (C-group) who underwent a combined of Le Fort I and horseshoe osteotomy and 14 patients (NC-group) who underwent a single-segment Le Fort I osteotomy were compared. Thirty-two (C-group) and 54 (NC-group) maxillary incisors were examined preoperatively and at 1-7 days, 14 days, and 3, 6, and 12 months postoperatively. The pulpal blood flow (PBF) was measured by laser Doppler flowmetry, and the pulpal sensibility (PS) was investigated by electrodiagnostics. RESULTS: In both groups, the PBF dropped to its lowest value at 1 day after surgery and increased thereafter. Though a temporary drop of the PBF was observed in the NC-group on day 4, the PS recovered earlier in the NC-group than in the C-group. CONCLUSION: These results suggest that the method of maxillary osteotomy influences the postoperative change of the PBF and recovery of the PS in the maxillary teeth.     

Laser doppler flowmetry in the assessment of tooth vitality after Le Fort I osteotomy

The aim of the present study was to evaluate pulp vitality in 15 patients, 11 to 29 months after a Le Fort I osteotomy. Assessment of pulpal blood flow was obtained by means of laser Doppler flowmetry, and it was measured bilaterally from the first maxillary premolar to the central incisor. The results were compared with those obtained by electric pulp testing in the same teeth. In addition, periodontal ligament perception was evaluated by applying axial loads to the central incisors. Radiographs were also studied. Fourteen subjects served as a control group. There was no significant difference between the level of pulpal blood flow in the teeth of the operated group compared with the control group. Twenty-one per cent of the teeth in the group operated on were insensitive to electric pulp testing, and in the remaining 79% the mean threshold was significantly higher than in the corresponding teeth in the control subjects. Similarly, the axial load threshold for the incisors for the control subjects was below 5 g, but in the group operated on 66% had a threshold above 5 g. These experiments clearly demonstrate that teeth without normal innervation can have an intact blood supply and be vital.     

The tissue reactions after capping of dog teeth with calcium hydroxide experimentally crammed into the pulp space

The pulps of 48 permanent dog teeth, incisors and canines, were evaluated histopathologically after capping treatment with pure calcium hydroxide placed by two methods: the experimental method, in which the calcium hydroxide was crammed into the pulpal space via the exposure site, and the usual method of direct pulp capping (controls). The results were recorded after periods of 2, 15, and 69 days. The healing process with hard-tissue formation was more evident in the experimentally capped teeth, despite the fact that pulpal necrosis occurred in a higher proportion of these teeth after use of this method of placement of the calcium hydroxide.     

The effect of pulp obliteration on pulpal vitality of orthodontically intruded traumatized teeth

Limited information exists on the impact of pulp obliteration on pulpal vitality of orthodontically treated traumatized teeth. Pulpal condition was examined in 269 traumatized maxillary incisors after orthodontic intrusion (OT group) and in 193 traumatized maxillary incisors without subsequent orthodontic treatment (C group). According to the degree of initial pulp obliteration, the teeth were divided into three categories: teeth without, teeth with partial, and teeth with total pulp obliteration. Teeth in the OT group revealed a significantly higher rate of pulp necrosis than teeth in the C group (p < 0.001). In addition, teeth in the OT group with total pulp obliteration showed a significantly higher rate of pulp necrosis than teeth without (p < 0.001) or only partial pulp obliteration (p = 0.025). The results indicate that traumatized teeth with total pulp obliteration have a higher susceptibility to pulpal complications during orthodontic intrusion than traumatized teeth without or only partial pulp obliteration.     

Analysis and comparison of pulp vitality after total and segmental LeFort I osteotomy

A more systematic electrical testing of pulp vitality demonstrated that the recovery rate of pulp vitality was 89.5% after 12 months of total and segmental LeFort I osteotomy. Segmental LeFort I osteotomy only imposed an interference to the speed of pulp vitality recovery. In other words, the recovery rate of pulp vitality in segmental LeFort I osteotomy was comparable to that in total LeFort I osteotomy. Maxillary segmentation inflicted a minimum damage to its adjacent teeth if clinical manipulation was meticulous and skillful. Interdental osteotomy did not exert an apparent effect on the recovery of pulp vitality and the positive rate of pulp vitality in the teeth close to it was roughly similar with that of homonymous teeth on the opposite side or their adjacent teeth on the same side.     

The effect of splinting upon periodontal and pulpal healing after autotransplantation of mature and immature permanent incisors in monkeys

The effect of splinting upon periodontal and pulpal healing after autotransplantation of teeth with complete and incomplete root formation was studied in 16 green Vervet monkeys (Cercopithecus aethiops). 2 maxillary incisors were extracted in each monkey and autotransplanted to the contralateral socket. One of these teeth was stabilized with an acrylic splint for either 2 or 6 weeks, while the other incisor was non-splinted. The animals were sacrificed 8 weeks after autotransplantation and the autotransplanted teeth were examined histologically. The following histologic parameters were registered for each tooth: surface resorption, inflammatory resorption, replacement resorption (ankylosis), downgrowth of pocket epithelium, periapical inflammatory changes and extent of pulp necrosis. The histometric analysis demonstrated that splinting increased the extent of pulp necrosis and inflammatory root resorption compared to non-splinting. Furthermore, the extent of normal periodontium was decreased among the splinted teeth, when compared to the non-splinted teeth. It is concluded that splinting not only failed to improve healing but apparently exerted a harmful effect upon periodontal and pulpal healing after autotransplantation.     

Fate of vital pulps beneath a metal-ceramic crown or a bridge retainer

AIM: To investigate the incidence of and factors associated with pulpal necrosis in vital teeth restored with metal-ceramic crowns (CMCs) or crowned as part of a fixed-fixed bridge. METHODOLOGY: Patients who had a CMC or bridge retainer (BR) placed on a tooth with no previous history of root canal treatment from 1981 to 1989 were retrieved from computer records. The collated patients were randomly selected and their clinical records examined. Those who satisfied the inclusion criteria were contacted and offered a review. After clinical examination, long-cone paralleling periapical radiographs were taken of the selected teeth, which were then assessed by two precalibrated operators to ascertain the pulpal status. Factors that might contribute to loss of pulp vitality and the tooth type were also recorded. The collected data were analysed statistically using the chi-square test and subject to Bonferroni adjustment where indicated. RESULTS: The numbers of preoperatively vital teeth in the CMC and BR groups were 122 and 77, and the mean observation periods were 169 +/- 25 (SD) and 187 +/- 23 months, respectively. In the CMC group, 19 failed cases (15.6%) were due to an endodontic reason; total number of failures was 34. In the BR group, 25 (32.5%) showed signs of pulpal necrosis; a significant association with maxillary anterior teeth was noted. The survival rates for pulp vitality were 84.4% (CMC) and 70.8% (BR) after 10 years, and 81.2% (SC) and 66.2% (BR) after 15 years. The difference between the two groups was significant. CONCLUSION: The survival of the vital pulp in teeth restored with a single-unit CMC was significantly higher than those serving as an abutment of a fixed-fixed bridge. Maxillary anterior teeth used as bridge abutments had a higher rate of pulpal necrosis than any other tooth types.     

Histological evaluation of enamel matrix derivative as a pulpotomy agent in primary teeth

PURPOSE: The purpose of this study was to evaluate histologically the effect of an enamel matrix derivative as a pulpotomy agent in primary canines. METHODS: Ten carious primary canines among teeth deemed for serial extraction were selected for this study. Emdogain gel was used as the pulp dressing material on the amputated pulp stumps. Teeth were extracted postoperatively after: (1) 1 week; (2) 2 weeks; and (3) 6 months. The extracted teeth were examined histologically to assess the response of the pulp to Emdogain gel after the pulpotomy procedure. RESULTS: Of the teeth extracted after 1 week, the amputated pulpal surface was lined by a thin, nearly continuous cellular layer. Generalized congestion was accompanied by an increase in angiogenesis. Of the teeth extracted after 2 weeks, most showed small islands of dentin-like tissue at different stages of mineralization. Of the teeth extracted after 6 months, several different histological pictures were viewed. Most of the teeth showed coalescing islands of dentin-like tissue trying to bridge the full width of the coronal pulp at the interface between the wounded and unharmed pulp tissue below the amputation site. CONCLUSION: Based on these experiments, Emdogain gel shows promising results as a valuable material for use in pulpotomy procedures, especially in the primary dentition.