Posterior Bite Collapse

Journal of Oral Rehabilitation 1998 25; 376–385Posterior bite collapse – revisited A. SHIFMAN, B-Z. LAUFER & H. CHWEIDAN Department of Oral Rehabilitation, The Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel SUMMARY Although there are different definitions of of lips and tongue, bruxism, habits, as well as the posterior bite collapse, only the classical definition presence of advanced periodontal disease or of Amsterdam provides a definite diagnosis and malocclusions, should be ruled out before the treatment plan. This situation entails a subtle loss diagnosis of posterior bite collapse can be made. The of the occlusal vertical dimension with resultant complexity of differential diagnosis is illustrated flaring of the maxillary incisors. Other causes for with three case reports. flaring, such as derangements of form and functions drift, resulting from space loss, because of the lesion of Introduction caries, tooth loss, or an imbalance of the anterior Characteristic tooth movements have been described as component of force’. (Amsterdam, 1974). Obviously, an undesirable sequela of loss of the mandibular first this sequence can take place only in Angle Class I molar, especially if it occurs at a young age (Salzman, normocclusions. The slight loss of OVD sufficient to 1938; Erlich & Yaffe, 1983). Changes in tooth positions overload the maxillary anterior teeth, may not were observed not only in the affected segment and in necessarily be detected clinically by increased the opposing dental arch, but also in the anterior region. interocclusal rest space (free way space). Similar The term posterior bite collapse (PBC) has been coined consequences of PBC were denoted: ‘the mandibular for this phenomenon inasmuch as it is attributed to loss anterior teeth that initially were in light or no contact of occlusal vertical dimension (OVD), (Amsterdam & with the palatal surfaces of the maxillary anterior teeth Abrams, 1968; Amsterdam, 1974). Other terms used in now contact heavily, resulting in flaring of the maxillary the literature are: collapse of the bite (Ramfjord & Ash, anterior teeth’. (Amsterdam & Abrams, 1973). They 1966), collapse of the occlusion (Stern & Brayer, 1975), further explain that: ‘the open contacts frequently posterior overclosure (Academy of Prosthodontics, initiate an adult or secondary tongue-thrusting habit, 1994). and the mandibular anterior teeth can also flare’. The classic description of Amsterdam (1974) is that: (Amsterdam & Abrams, 1973). As anterior tooth ‘we also see gradual loss of the protective function of the posterior teeth resulting in excessive stress in loading movements can be initiated by tongue-thrusting habits of maxillary anterior teeth and their ‘fanning’ (resulting per se, the authors do not present a clue for differential from migration of the maxillary anterior teeth). This is diagnosis of these two aetiologies. usually accompanied by ‘fanning’ of the mandibular A different mechanism for the flaring of the maxillary anterior teeth, which are seeking containment, with anterior teeth in cases of loss of the mandibular first resultant loss of occlusal vertical dimension.’ He further molar is proposed by Ramfjord & Ash (1966). They states that: ‘it frequently takes place in much more ascribed it to: ‘an increased slide in centric hitting the subtle fashion in any instance of accelerated mesial front teeth, and by abnormal occlusal relations that 376 © 1998 Blackwell Science Ltd a requisite sign for PBC (Brayer posterior segment was restored at that time and 2 years & Stern. mechanisms for this phenomenon can take place. There was a nearly complete prognosis and treatment plan. Journal of Oral Rehabilitation 25. 1. dental caries and faulty restorations. Perio- dontal involvement in these cases is considered secondary and as a result of tooth migrations or mal- alignments. She however. Maxillary dental arch of patient 1. Their suggested treatment is a combined periodontal. orthodontic and prosthodontic effort.b) proposes that the primary causes of PBC are periodontal disease and dental caries. Rosenberg (1987) also suggests that Patient 1 accelerated occlusal wear may be one of the aetiologic factors present in PBC. Stern & Brayer (1975) concede that in loss of posterior occlusal support: ‘a forward drift of the mandible will take place. repositioning of the mandible. anterior flaring in both arches situation described by Amsterdam (1974) to divergent was evident (Fig.’ According to these authors. spaces between teeth. 1970). The maxillary left migration is. congenital Fig. recalled that about 20 years of PBC is a far remote clinical picture from that described ago she lost the left first molars and right second by Amsterdam (1974). 1). 2. It seems that a subtle loss of OVD can ago the mandibular right posterior segment was also cause the anterior teeth to migrate. 376–385 . manifested both in loss of posterior occlusal support and anterior Fig. The inclusion of such a patient in the realm unaware of the cause of this situation and denied any oral habits. many aetiologic factors may lead to reduction or loss of posterior occlusal support: loss of arch integrity as in early loss of a tooth. space closure of the maxillary second premolar (Figs 2 © 1998 Blackwell Science Ltd. although other restored. He illustrates this by a case A 52-year-old woman complained of spacing of the report of a patient missing posterior teeth with extreme maxillary and mandibular teeth that had gradually wear of her anterior teeth and a pseudo Class III developed during the previous 5 years. These occlusal changes may disrupt the neuromuscular balance of the Patient reports masticatory system and may even cause muscle spasm and MPD syndrome. however. This search for new support in the region of the front teeth thus leads to an increased load on upper incisors. lingually (Figs 4 & 5). Rosenberg (1988a. Extra-oral examination did not reveal any Reviewing the literature reveals incongruity in the abnormalities. tooth attrition and malocclusion. although redefine the concept of PBC through apparently similar the mandibular left molar was tipped mesially and patient reports. tooth mobility and migration and eventually to PBC. that. The occlusion in the loss of OVD. The aim of this article is therefore to posterior segments was maintained bilaterally. lips were competent and in normal shape various definitions of PBC from a well defined clinical and tone. Amsterdam & Abrams (1968) also allude that PBC may emanate from the concurrence of loss of OVD and anterior displacement of the mandible. Both arches were extensively clinical situations that encompass every case displaying restored posteriorly (Figs 2 & 3). POSTERIOR BITE COLLAPSE – REVISITED 377 have induced a change of masticatory habits and muscle tonicity rather than a loss of vertical dimension’. however. differ in pathogenesis. It is claimed that anterior tooth premolars in both dental arches. The patient was situation. Intra-orally. These diseases can lead to occlusal trauma. Front view of occluded dentition of patient 1. iatrogenic causes in previous occlusal restorations. 6). Diagnosis. Most of the teeth were mobile (grade contact position. Maximal intercuspal position coincided displayed an approximate loss of one-third of the with the retruded contact position. 3. 4. 376–385 . Small amounts of supragingival and bleeding on probing. Several consultations in the past recommended periodontal surgical treatment which she refused because of the fear of postoperative unaesthetic root exposure. Left-side view of occluded dentition of patient 1. Nevertheless. Radiographically. S H I F M A N et al. Extra-oral examination did not reveal any abnormalities. Although not complaining of pain or severe discomfort. No bone loss was evident in the posterior segments (Fig. She was then also aware of occasional daytime tooth clenching. Although the mandibular left second molar Fig. None of the teeth were mobile or sensitive to premolar. birth 5 months ago. Right-side view of occluded dentition of patient 1. she reported that her husband made her aware of night-time tooth grinding that appeared a few months ago. 5. Her general medical condition was noncontributory. Overall pocket (Figs 10 & 11). Patient 2 A 31-year-old married woman complained of flaring of Fig. oedematous depths varied between 2 mm to 5 mm with few sites and receded. the patient had remained under regular periodontal maintenance therapy and was highly motivated for good oral hygiene. the patient was very anxious about losing her dentition. Mandibular dental arch of patient 1. She gave Fig. The temporomandibular joints and the mandibular elevator muscles were not tender on palpation. the maxillary anterior teeth 2 mm to 3 mm. A year before the present examination. Overall pocket depths the range of 2 mm to 3 mm. except for slight deviation in open–close cycle. Chronic periodontitis adult type (moderate). was missing. Interocclusal rest space was within the range of 3 mm. occlusal adjustments were performed to allow free mandibular excursions. Journal of Oral Rehabilitation 25. the latter mainly in position was about 1 mm anterior to the retruded maxillary incisors. Overbite was 3 mm © 1998 Blackwell Science Ltd. Interocclusal rest space was within subgingival calculus were present.378 A . Anterior migration of the teeth induced by posterior overclosure and secondary tongue thrust. and despite the crossbite on the right and the fractured buccal cusp of the maxillary left first & 4). molar support was deemed to be adequate percussion. although she had been smoking for the last 10 years (10–20 cigarettes per day). In addition. her upper anterior teeth which occurred 6 years ago. Overbite was 3 mm and the overjet 1). Maximal intercuspal varied from 3 mm to 7 mm. Gingival tissues were red. in particular the upper incisors. alveolar bone whereas the mandibular anterior teeth displayed loss of about half of this bone. Intra-oral examination showed spacing of maxillary incisors in an almost completely preserved dentition with few restorations in the molar teeth (Figs 7–9). Carious lesions or wear facets were not detected. Fremitus was not detected. Early onset of generalized periodontitis with was rectified with a removable orthodontic appliance. 8. from gum swelling and. recent onsent bruxism. 9. Patient 3 A 36-year-old woman complained of mobility of her and overjet 2 mm. She reported that at the age of 17 she suffered of the bone posteriorly. Front view of occluded dentition of patient 2. 12). 376–385 . Maxillary dental arch of patient 2. Fig. generalized loss of lower anterior teeth and of unaesthetic appearance of the alveolar bone was evident in both dental arches. A the upper anterior teeth that were spaced and labially loss of two-thirds of the bone anteriorly and one-half inclined. 6. © 1998 Blackwell Science Ltd. Periapical dental radiographs of patient 1. Radiographically. Mandibular dental arch of patient 2. Fig. was estimated (Fig. spacing and flaring of the front teeth developed. Fig. POSTERIOR BITE COLLAPSE – REVISITED 379 Fig. upper first molars. Right-side view of occluded dentition of patient 2. At the age of 22 the flaring Diagnosis. 10. 7. Fig. a year later. Journal of Oral Rehabilitation 25. Periodontally induced anterior but relapsed after a year following bilateral loss of the migration of maxillary incisors. Posterior occlusal contacts were diminished molar teeth were missing bilaterally with partial closure (Figs 16 & 17). The mandibular maximal intercuspation and the retruded contact dental arch was complete (Fig. Front view of occluded dentition of patient 3. Left-side view of occluded dentition of patient 2. Both the maxillary second premolar and first 3 mm. In the posterior segments. Fig. spacing between the grade 3 mobility with firey red gingival tissues and maxillary central and lateral incisors was observed purulent exudate. Extra-oral examination did not reveal any abnormalities. 14). Overbite was 2 mm and overjet (Fig. Intraorally. 13. 15. The mandibular central incisors displayed the bone. 15). A difference of 2 mm existed between of the edentulous spaces (Fig. Fig. Journal of Oral Rehabilitation 25.380 A . 376–385 . Periapical dental radiographs of patient 2. 12. mandibular anterior teeth. general pocket depths were Radiographically. Interocclusal rest space was 1 mm to 2 mm. there was less © 1998 Blackwell Science Ltd. Fig. complete alveolar bone loss was moderate (3 mm to 5 mm) including the maxillary evident around the mandibular central incisors. Maxillary dental arch of patient 3. Fig. No of a few sites of deep periodontal pockets notably the such habits as tongue thrusting could be demonstrated. 14. S H I F M A N et al. 13). The anterior teeth which displayed grade 1 mobility and maxillary anterior teeth displayed loss of about half of fremitus. 11. Mandibular dental arch of patient 3. With the exception position. Fig. . but maximal forces which rarely exist during normal function. Diagnosis. can result in the tooth moving to a position relieving this effect. force they exert on the teeth). splaying. 376–385 . that there are several positions of stability. (1963) is defined as that position of a tooth from which it will not be moved by the natural enviromental forces acting thereon. © 1998 Blackwell Science Ltd. or with trapped lower lip. Perio- dontally induced anterior tooth migration perpetuated Arch integrity by posterior overclosure. When he added 2 mm thick labial or lingual extensions to teeth. and the surrounding bone and periodontal tissues. namely forces from contiguous Labial migration of the anterior teeth. summed up according to their relative duration in 24 h. e. POSTERIOR BITE COLLAPSE – REVISITED 381 extensive bone loss but angular osseous defects and denotes loss of arch form and occlusal stability. This equilibrium includes all the forces that may affect tooth position. opposing and fanning. It has been assumed that when teeth are stable in their position. external objects such as food. there is an equilibrium of forces acting on Discussion them. and swallowing. Lear & Moorrees (1969) measured force magnitude of the musculature during rest. occlusal stability is maintained by three factors: arch integrity. However. 18. Changing this balance of forces. in normocclusion. 18). described as muscles such as the tongue and lips. Kydd (1957) measured tongue and lip muscle forces and found statistically significant differences between them. In addition. Weinstein et al. muscular dystrophy. Early onset localized periodontitis. Fig. occlusal relations and the periodontal health. speech. Journal of Oral Rehabilitation 25. Left-side view of occluded dentition of patient 3. 16. or flaring is a discerning sign that adjacent teeth. This sign etc. Right-side view of occluded dentition of patient 3. Fig. fingers. The furcation involvements were detected (Fig. facial paralysis and cerebral palsy as an indirect proof for this theory. (1963) lists several pathological conditions associated with mal- alignment of teeth such as: aglossia. he did not measure habitual. Periapical dental radiographs of patient 3. The ‘equilibrium position’ theory presented by Weinstein et al. regularly induces patients to seek treatment. he showed by mathematical plotting of the angulation of the anterior teeth and the combined angulation of the lips (correlated with the Fig. mastication.g. the latter being considerably less. he could demonstrate movement of the teeth to the opposite direction reaching plateau within a few weeks. 17. Hochman & Erlich (1992) Currently. A slight increase in OVD of Prosthodontics. This is regarded as secondary occlusal traumatism procedure permits unhindered orthodontic movements (Academy of Prosthodontics. Flaring can occasionally be treated only at the level of The foregoing discussion is based on the premise that the anterior segments. Flaring of maxillary incisors can be achieved by orthodontic or by spontaneous can be induced even by physiologic forces acting upon eruption of the posterior teeth (Yaffe & Ehrlich. This bone. Even a slight loss of OVD can Periodontal involvement overload the maxillary incisors. improves overbite/overjet relations can thus be affected by secondary occlusal traumatism and thus reduces the load on these teeth. combined with but have adequate alveolar bone support with the tooth alterations for occlusal clearance and permanent presence of mild periodontal disease. Ramfjord & Ash. 1994). 1989). flaring of the therefore to be considered. showing that the dental arch of the mandible. Other determinants of tooth anterior teeth are splinted (Waltimo & Ko¨no¨nen. 1971). greater forces can be exerted when the arch (Proffit. It is even in situations where no loss of OVD is present. as well as to reposition into a new stable equilibrium. 1985) these teeth when there is a substantial loss of alveolar or by prosthetic means as indicated for patient 1. hypothesized that once secondary tongue habits are Recently. It seems that this type of maxillary incisors slightly contact or do not contact flaring can only take place when the neuromuscular (Andersson & Myers. 1978). maxillary incisors results from these teeth being hit by the opposing mandibular incisors during protrusive movements (Stern & Brayer. with the lingual forces being greater. neuromuscular inhibition (Williamson & Lundquist. resulting in their flaring. such as may occur in contact when pressure is applied during maximal closure bruxism. no permanent splint of the anterior teeth been correlated to alveolar bone loss and to the presence is required and these teeth may even spontaneously of acute inflamation around these teeth.382 A . This splinting of these teeth. at the most. It appears that the resultant equilibrium is not a simple 1983).. positions and arch form such as the occlusion have Some authors contend that in PBC. They suggest that this protrusive intercuspal position (Shillingburg. Yaffe. Occlusal relations 1966). a considerable imbalance was found. aborigines’ large dental arches can not be explained by Two mechanisms were proposed to explain how the tongue pressure. (2) disclusion evokes a the tongue and perioral musculature fits his equation. 376–385 . factor for anterior flaring. However. pattern may be regarded as an additional aetiologic 1978. They found an inverse capable of protecting the multi-rooted posterior teeth relationship between tongue pressure and arch size. (Riise & Ericsson. namely by orthodontic in PBC maxillary incisors are subjected to excessive load movements of the inclined incisors. Hobo & Whitsett. 1994). McGlone With respect to the anterior guided occlusion. this is a specific situation (seven subjects). 1988). migration of maxillary anterior teeth has controlled. Mohl et al. At maximal intercuspation. a different treatment is referred to as primary occlusal traumatism (Academy approach should be adopted. 1975. This pattern in sirognathographic sagital tracings of scheme infers that the anterior teeth protect the deliberate mastication. As loss of OVD the loss of more than three posterior teeth in the same © 1998 Blackwell Science Ltd. 1984). Maxillary incisors of the anterior teeth. action of labio-lingual muscular forces within the dental Indeed. 1983) or with the change of head posture (Mohl. it is & Barret (1975) examined tongue and lip pressures in hard to conceive how uni-rooted maxillary incisors are Australian aborigines. Journal of Oral Rehabilitation 25. S H I F M A N et al. Although the study was conducted on a small sample in these patients is occult. A different approach to this problem load acting upon maxillary incisors is reduced during was used by Brader (1972) who developed a complex excursive movements: (1) in the class III lever system mathematical solution. incisors function on a longer lever arm fits a trifocal ellipse and the difference in forces between than molars (Dawson. All these patients shared severe posterior teeth in mandibular excursions by disocclusion attrition of the anterior teeth or moderate attrition with and that the posterior protect the anterior teeth at the fremitus or flaring. so when forces are applied lingually on inclined planes. Furthermore. which rightfully deserves a separate diagnosis of PBC. the mutual protection concept is the showed that a group of patients exhibited a protrusive favourable scheme for physiologic occlusion. 1994). Proffit. these teeth may protective mechanism has failed. However. Patient 1 presented with anterior flaring occurring To define a separate disease entity one has to describe after loss of posterior teeth. appeared because of periodontal disease precending the Zammit & Dongari. is to onset periodontitis and is considered to have a better be evaluated thereafter. anterior occlusal impairment. The rehabilitative correction of the flaring followed by permanent splinting treatment should therefore start in the posterior of the maxillary incisors. early onset periodontitis. segment. 1973. © 1998 Blackwell Science Ltd. prognosis and treatment plan (Table 1). Comparison of findings. by increasing the OVD. It is thus advantageous to prognosis than patient 2. and loss of OVD and therefore the situation should not be localized early onset periodontitis (patient 3).. a combined loss of OVD or flaring that is caused by other factors. Rosenberg. instituted. Amsterdam. there was no sign of generalized early onset periodontitis (patient 2). no more a clinical situation featuring common pathogenesis. broaden Differential diagnosis the definition of PBC to a variety of conditions associated with loss of OVD (Stern & Brayer. EOP. they differ in pathogenesis. Amsterdam. dentition (Martinez-Canut et al. Other authors. orthodontic and prosthodontic treatment can be with or without involvement of the posterior segments. however. Prognosis is guarded. their diagnosis Patient 2 presented with severe periodontal disease is subdivided into adult periodontitis (patient 1). aforementioned parameters of disease. AOI. to control bruxism. 1975. Although flaring is a sign common to all the patients 1987. occlusal impairment. The Abrams. with the generalized type of preserve the term PBC for this clinical situation. patient 3 presented in this article. This sequence of events do not conform to that described septal peridontal fibres. 1997). posterior bite collapse. This patient should be treated with holds true for the diagnosis of loss of OVD. Amsterdam & an interocclusal device (night guard) is indicated. pathogenesis. Journal of Oral Rehabilitation 25. 1974). Also. 1974. all the the maxillary incisors was evident. may also be regarded as a PBC-situation. 1988a. Also it has been ‘Hopeless’ mandibular incisors can be replaced by a reported that anterior spacing can spontaneously be fixed or removable prosthesis. by Amsterdam for PBC (Amsterdam & Abrams. The classic intensive periodontal protocol. For instance. 376–385 . Despite the flaring. attributed to disruption and reintegration of the trans. diagnoses and treatment approaches in described patient reports Patient Flaring Region of Region of Occlusal Peridontal Region of Region of Need for Need for primary secondary diagnosis diagnosis primary secondary increasing anterior impairment impairment restorative restorative OVD splint treatment treatment 1 1 Posterior Anterior PBC Adult peridontitis Posterior – (Anterior?) 1 – 2 1 Anterior – AOI General EOP Anterior – – 1 3 1 Anterior Posterior APOI Local EOP Posterior Anterior 1 1 PBC. description of PBC (Amsterdam. According to this definition. The same diagnosed as PBC. 1968. 1973). Need for a Patient 3 presented with a localized type of early rehabilitative treatment in the anterior segment. anterior and posterior occlusal impairment. orthodontic anterior segment from overloading.b). APOI. flaring closed after surgical peridontal treatment (Brunsvold. and bone loss. In this patient. This situation patients described in this article were afflicted with corroborates the classical description of PBC periodontitis. than a one-third loss of the alveolar bone surrounding prognosis and treatment plan. is that the anterior flaring is suggested rehabilitative treatment for this patient is caused by failure of the posterior occlusion to protect the limited to the anterior segment. This phenomenon is loss of the maxillary teeth and subsequent loss of OVD. should not be confused with other situations involving 1996). restoration of the OVD and permanent The latter may be termed as anterior or anteroposterior splinting of the rectified maxillary incisors is indicated. 1974). In this patient. 1997). namely. respectively (Table 1). It this disease (American Academy of Periodontology. When the disease is controlled. 1968. POSTERIOR BITE COLLAPSE – REVISITED 383 Table 1. As they greatly differed in the (Amsterdam & Abrams. J. 50. 1974. 541. and habitual MARTINEZ-CANUT.W.M. To diagnose PBC. 55. Quintessence Publishing (v) Expanding the definition of PBC to a variety of Co. ERLICH. 8 years after extraction. J. KYDD. (1968) Periodontal prosthesis.384 A . 1968. p. primary tongue thrusting. Chicago. M. that some subjects lost the tooth as much as 20 years AMSTERDAM. & YAFFE. 5. occlusal parafunctions. (iii) Flaring of maxillary incisors is a requisite sign for 50.C. 646. L. Journal of Dental Research. Possible explanations AMSTERDAM.D. Solberg & G. individual case. Louis... & ABRAMS. (1983) The effect of first molar loss on the interocclusal rest space is an unreliable sign for PBC. (1984) The role of head posture in mandibular different disease entity that warrants further research.W. 226. (1973) Periodontal prosthesis. A. K. the perioral and lingual musculature. there are no known clinical studies that assess the prevalence of PBC in a patient population. G. septal fibres may be remodelled and their activity ANDERSSON. does not contribute to a MOHL. Salzman (1938) The authors wish to thank the following graduate found mesial drift of the second molar in more than students for providing the illustrations and patient 90% of the subjects. to 8 mm for maxillary second molars. & LORCA. In: previously. 42. L. G. dentition and the periodontium. St. (1972) Dental arch form related with intraoral forces. It features a DAWSON.E. L. AMERICAN ACADEMY OF PERIODONTOLOGY (1996) Position paper. R.. 64. Quintessence Publishing Co. N.. BRUNSVOLD. CV Mosby Co. A change in the Problems. Journal of Prosthetic Dentistry. Louis. 1973) is valid. ZARB. Prevalence of PBC (vi) PBC is probably an infrequent clinical situation and is encountered only in Angle Class I occlusal relations.E. BRADER. CV Mosby Co. Dental Association. PBC but not a pathognomonic one. Chicago. This peridontal therapy. p. advanced LEAR. 1983). © 1998 Blackwell Science Ltd. 4th edn. (iv) The role of excursive mandibular movements as a Journal of Clinical Periodontology. 7. edn. In: for this phenomenon are: (1) achieving a definite Periodontal Therapy (eds H. 379.M. pp. St.. and distal drift of premolars in reports for this article: Dr Yoseph Nissan (patient 1). A. self-limiting (Erlich & Yaffe. M. PR 5 C. (2) trans. American Journal of Orthodontonics. (1974) Twenty-five years in retrospect. M. (ii) PBC is a specific case of loss of OVD. G. Some studies. Journal of maxillary or mandibular first molar. Journal of Oral Rehabilitation 25. (1957) Maximum forces exerted on the dentition by other contributing factors for flaring must be excluded. CV Mosby Co. 67. CARRASQUER.. however. & MOORREES. which is considered the main aetiologic factor for PBC. (1969) Buccolingual muscle force and dental arch form. 183. p. Dr Harry Chweidan (patient 3). found that in 61% Periodontology. J.A. C. function. p. various habits. A.. A. Restorative Dentistry.D. 61. & RUGH. 4. atypical swallowing.S.F. 492. (1971) Nature of contact in centric reduced.A. Goldman & D. St. C. 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